5401 lines
124 KiB
C
5401 lines
124 KiB
C
/*
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* ring buffer based function tracer
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*
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* Copyright (C) 2007-2008 Steven Rostedt <srostedt@redhat.com>
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* Copyright (C) 2008 Ingo Molnar <mingo@redhat.com>
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*
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* Originally taken from the RT patch by:
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* Arnaldo Carvalho de Melo <acme@redhat.com>
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*
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* Based on code from the latency_tracer, that is:
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* Copyright (C) 2004-2006 Ingo Molnar
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* Copyright (C) 2004 Nadia Yvette Chambers
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*/
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#include <linux/ring_buffer.h>
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#include <generated/utsrelease.h>
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#include <linux/stacktrace.h>
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#include <linux/writeback.h>
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#include <linux/kallsyms.h>
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#include <linux/seq_file.h>
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#include <linux/notifier.h>
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#include <linux/irqflags.h>
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#include <linux/irq_work.h>
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#include <linux/debugfs.h>
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#include <linux/pagemap.h>
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#include <linux/hardirq.h>
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#include <linux/linkage.h>
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#include <linux/uaccess.h>
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#include <linux/kprobes.h>
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#include <linux/ftrace.h>
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#include <linux/module.h>
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#include <linux/percpu.h>
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#include <linux/splice.h>
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#include <linux/kdebug.h>
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#include <linux/string.h>
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#include <linux/rwsem.h>
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#include <linux/slab.h>
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#include <linux/ctype.h>
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#include <linux/init.h>
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#include <linux/poll.h>
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#include <linux/nmi.h>
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#include <linux/fs.h>
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#include <linux/sched/rt.h>
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#include "trace.h"
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#include "trace_output.h"
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/*
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* On boot up, the ring buffer is set to the minimum size, so that
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* we do not waste memory on systems that are not using tracing.
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*/
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int ring_buffer_expanded;
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/*
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* We need to change this state when a selftest is running.
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* A selftest will lurk into the ring-buffer to count the
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* entries inserted during the selftest although some concurrent
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* insertions into the ring-buffer such as trace_printk could occurred
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* at the same time, giving false positive or negative results.
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*/
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static bool __read_mostly tracing_selftest_running;
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/*
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* If a tracer is running, we do not want to run SELFTEST.
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*/
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bool __read_mostly tracing_selftest_disabled;
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/* For tracers that don't implement custom flags */
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static struct tracer_opt dummy_tracer_opt[] = {
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{ }
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};
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static struct tracer_flags dummy_tracer_flags = {
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.val = 0,
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.opts = dummy_tracer_opt
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};
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static int dummy_set_flag(u32 old_flags, u32 bit, int set)
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{
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return 0;
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}
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/*
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* To prevent the comm cache from being overwritten when no
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* tracing is active, only save the comm when a trace event
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* occurred.
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*/
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static DEFINE_PER_CPU(bool, trace_cmdline_save);
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/*
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* When a reader is waiting for data, then this variable is
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* set to true.
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*/
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static bool trace_wakeup_needed;
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static struct irq_work trace_work_wakeup;
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/*
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* Kill all tracing for good (never come back).
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* It is initialized to 1 but will turn to zero if the initialization
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* of the tracer is successful. But that is the only place that sets
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* this back to zero.
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*/
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static int tracing_disabled = 1;
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DEFINE_PER_CPU(int, ftrace_cpu_disabled);
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cpumask_var_t __read_mostly tracing_buffer_mask;
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/*
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* ftrace_dump_on_oops - variable to dump ftrace buffer on oops
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*
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* If there is an oops (or kernel panic) and the ftrace_dump_on_oops
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* is set, then ftrace_dump is called. This will output the contents
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* of the ftrace buffers to the console. This is very useful for
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* capturing traces that lead to crashes and outputing it to a
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* serial console.
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*
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* It is default off, but you can enable it with either specifying
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* "ftrace_dump_on_oops" in the kernel command line, or setting
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* /proc/sys/kernel/ftrace_dump_on_oops
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* Set 1 if you want to dump buffers of all CPUs
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* Set 2 if you want to dump the buffer of the CPU that triggered oops
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*/
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enum ftrace_dump_mode ftrace_dump_on_oops;
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static int tracing_set_tracer(const char *buf);
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#define MAX_TRACER_SIZE 100
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static char bootup_tracer_buf[MAX_TRACER_SIZE] __initdata;
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static char *default_bootup_tracer;
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static int __init set_cmdline_ftrace(char *str)
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{
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strncpy(bootup_tracer_buf, str, MAX_TRACER_SIZE);
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default_bootup_tracer = bootup_tracer_buf;
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/* We are using ftrace early, expand it */
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ring_buffer_expanded = 1;
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return 1;
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}
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__setup("ftrace=", set_cmdline_ftrace);
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static int __init set_ftrace_dump_on_oops(char *str)
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{
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if (*str++ != '=' || !*str) {
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ftrace_dump_on_oops = DUMP_ALL;
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return 1;
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}
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if (!strcmp("orig_cpu", str)) {
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ftrace_dump_on_oops = DUMP_ORIG;
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return 1;
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}
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return 0;
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}
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__setup("ftrace_dump_on_oops", set_ftrace_dump_on_oops);
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static char trace_boot_options_buf[MAX_TRACER_SIZE] __initdata;
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static char *trace_boot_options __initdata;
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static int __init set_trace_boot_options(char *str)
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{
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strncpy(trace_boot_options_buf, str, MAX_TRACER_SIZE);
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trace_boot_options = trace_boot_options_buf;
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return 0;
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}
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__setup("trace_options=", set_trace_boot_options);
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unsigned long long ns2usecs(cycle_t nsec)
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{
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nsec += 500;
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do_div(nsec, 1000);
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return nsec;
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}
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/*
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* The global_trace is the descriptor that holds the tracing
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* buffers for the live tracing. For each CPU, it contains
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* a link list of pages that will store trace entries. The
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* page descriptor of the pages in the memory is used to hold
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* the link list by linking the lru item in the page descriptor
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* to each of the pages in the buffer per CPU.
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*
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* For each active CPU there is a data field that holds the
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* pages for the buffer for that CPU. Each CPU has the same number
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* of pages allocated for its buffer.
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*/
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static struct trace_array global_trace;
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static DEFINE_PER_CPU(struct trace_array_cpu, global_trace_cpu);
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int filter_current_check_discard(struct ring_buffer *buffer,
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struct ftrace_event_call *call, void *rec,
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struct ring_buffer_event *event)
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{
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return filter_check_discard(call, rec, buffer, event);
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}
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EXPORT_SYMBOL_GPL(filter_current_check_discard);
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cycle_t ftrace_now(int cpu)
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{
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u64 ts;
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/* Early boot up does not have a buffer yet */
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if (!global_trace.buffer)
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return trace_clock_local();
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ts = ring_buffer_time_stamp(global_trace.buffer, cpu);
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ring_buffer_normalize_time_stamp(global_trace.buffer, cpu, &ts);
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return ts;
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}
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/*
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* The max_tr is used to snapshot the global_trace when a maximum
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* latency is reached. Some tracers will use this to store a maximum
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* trace while it continues examining live traces.
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*
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* The buffers for the max_tr are set up the same as the global_trace.
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* When a snapshot is taken, the link list of the max_tr is swapped
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* with the link list of the global_trace and the buffers are reset for
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* the global_trace so the tracing can continue.
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*/
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static struct trace_array max_tr;
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static DEFINE_PER_CPU(struct trace_array_cpu, max_tr_data);
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int tracing_is_enabled(void)
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{
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return tracing_is_on();
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}
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/*
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* trace_buf_size is the size in bytes that is allocated
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* for a buffer. Note, the number of bytes is always rounded
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* to page size.
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*
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* This number is purposely set to a low number of 16384.
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* If the dump on oops happens, it will be much appreciated
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* to not have to wait for all that output. Anyway this can be
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* boot time and run time configurable.
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*/
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#define TRACE_BUF_SIZE_DEFAULT 1441792UL /* 16384 * 88 (sizeof(entry)) */
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static unsigned long trace_buf_size = TRACE_BUF_SIZE_DEFAULT;
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/* trace_types holds a link list of available tracers. */
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static struct tracer *trace_types __read_mostly;
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/* current_trace points to the tracer that is currently active */
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static struct tracer *current_trace __read_mostly = &nop_trace;
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/*
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* trace_types_lock is used to protect the trace_types list.
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*/
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static DEFINE_MUTEX(trace_types_lock);
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/*
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* serialize the access of the ring buffer
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*
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* ring buffer serializes readers, but it is low level protection.
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* The validity of the events (which returns by ring_buffer_peek() ..etc)
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* are not protected by ring buffer.
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*
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* The content of events may become garbage if we allow other process consumes
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* these events concurrently:
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* A) the page of the consumed events may become a normal page
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* (not reader page) in ring buffer, and this page will be rewrited
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* by events producer.
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* B) The page of the consumed events may become a page for splice_read,
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* and this page will be returned to system.
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*
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* These primitives allow multi process access to different cpu ring buffer
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* concurrently.
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*
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* These primitives don't distinguish read-only and read-consume access.
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* Multi read-only access are also serialized.
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*/
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#ifdef CONFIG_SMP
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static DECLARE_RWSEM(all_cpu_access_lock);
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static DEFINE_PER_CPU(struct mutex, cpu_access_lock);
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static inline void trace_access_lock(int cpu)
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{
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if (cpu == TRACE_PIPE_ALL_CPU) {
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/* gain it for accessing the whole ring buffer. */
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down_write(&all_cpu_access_lock);
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} else {
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/* gain it for accessing a cpu ring buffer. */
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/* Firstly block other trace_access_lock(TRACE_PIPE_ALL_CPU). */
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down_read(&all_cpu_access_lock);
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/* Secondly block other access to this @cpu ring buffer. */
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mutex_lock(&per_cpu(cpu_access_lock, cpu));
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}
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}
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static inline void trace_access_unlock(int cpu)
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{
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if (cpu == TRACE_PIPE_ALL_CPU) {
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up_write(&all_cpu_access_lock);
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} else {
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mutex_unlock(&per_cpu(cpu_access_lock, cpu));
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up_read(&all_cpu_access_lock);
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}
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}
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static inline void trace_access_lock_init(void)
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{
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int cpu;
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for_each_possible_cpu(cpu)
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mutex_init(&per_cpu(cpu_access_lock, cpu));
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}
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#else
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static DEFINE_MUTEX(access_lock);
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static inline void trace_access_lock(int cpu)
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{
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(void)cpu;
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mutex_lock(&access_lock);
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}
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static inline void trace_access_unlock(int cpu)
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{
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(void)cpu;
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mutex_unlock(&access_lock);
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}
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static inline void trace_access_lock_init(void)
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{
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}
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#endif
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/* trace_wait is a waitqueue for tasks blocked on trace_poll */
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static DECLARE_WAIT_QUEUE_HEAD(trace_wait);
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/* trace_flags holds trace_options default values */
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unsigned long trace_flags = TRACE_ITER_PRINT_PARENT | TRACE_ITER_PRINTK |
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TRACE_ITER_ANNOTATE | TRACE_ITER_CONTEXT_INFO | TRACE_ITER_SLEEP_TIME |
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TRACE_ITER_GRAPH_TIME | TRACE_ITER_RECORD_CMD | TRACE_ITER_OVERWRITE |
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TRACE_ITER_IRQ_INFO | TRACE_ITER_MARKERS;
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static int trace_stop_count;
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static DEFINE_RAW_SPINLOCK(tracing_start_lock);
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/**
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* trace_wake_up - wake up tasks waiting for trace input
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*
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* Schedules a delayed work to wake up any task that is blocked on the
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* trace_wait queue. These is used with trace_poll for tasks polling the
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* trace.
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*/
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static void trace_wake_up(struct irq_work *work)
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{
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wake_up_all(&trace_wait);
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}
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/**
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* tracing_on - enable tracing buffers
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*
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* This function enables tracing buffers that may have been
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* disabled with tracing_off.
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*/
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void tracing_on(void)
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{
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if (global_trace.buffer)
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ring_buffer_record_on(global_trace.buffer);
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/*
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* This flag is only looked at when buffers haven't been
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* allocated yet. We don't really care about the race
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* between setting this flag and actually turning
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* on the buffer.
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*/
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global_trace.buffer_disabled = 0;
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}
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EXPORT_SYMBOL_GPL(tracing_on);
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/**
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* tracing_off - turn off tracing buffers
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*
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* This function stops the tracing buffers from recording data.
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* It does not disable any overhead the tracers themselves may
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* be causing. This function simply causes all recording to
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* the ring buffers to fail.
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*/
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void tracing_off(void)
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{
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if (global_trace.buffer)
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ring_buffer_record_off(global_trace.buffer);
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/*
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* This flag is only looked at when buffers haven't been
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* allocated yet. We don't really care about the race
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* between setting this flag and actually turning
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* on the buffer.
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*/
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global_trace.buffer_disabled = 1;
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}
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EXPORT_SYMBOL_GPL(tracing_off);
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/**
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* tracing_is_on - show state of ring buffers enabled
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*/
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int tracing_is_on(void)
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{
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if (global_trace.buffer)
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return ring_buffer_record_is_on(global_trace.buffer);
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return !global_trace.buffer_disabled;
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}
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EXPORT_SYMBOL_GPL(tracing_is_on);
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static int __init set_buf_size(char *str)
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{
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unsigned long buf_size;
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if (!str)
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return 0;
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buf_size = memparse(str, &str);
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/* nr_entries can not be zero */
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if (buf_size == 0)
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return 0;
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trace_buf_size = buf_size;
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return 1;
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}
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__setup("trace_buf_size=", set_buf_size);
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static int __init set_tracing_thresh(char *str)
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{
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unsigned long threshold;
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int ret;
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if (!str)
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return 0;
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ret = kstrtoul(str, 0, &threshold);
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if (ret < 0)
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return 0;
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tracing_thresh = threshold * 1000;
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return 1;
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}
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__setup("tracing_thresh=", set_tracing_thresh);
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unsigned long nsecs_to_usecs(unsigned long nsecs)
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{
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return nsecs / 1000;
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}
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/* These must match the bit postions in trace_iterator_flags */
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static const char *trace_options[] = {
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"print-parent",
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"sym-offset",
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"sym-addr",
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"verbose",
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"raw",
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"hex",
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"bin",
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"block",
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"stacktrace",
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"trace_printk",
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"ftrace_preempt",
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"branch",
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"annotate",
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"userstacktrace",
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"sym-userobj",
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"printk-msg-only",
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"context-info",
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"latency-format",
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"sleep-time",
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"graph-time",
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"record-cmd",
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"overwrite",
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"disable_on_free",
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"irq-info",
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"markers",
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NULL
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};
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static struct {
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u64 (*func)(void);
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const char *name;
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int in_ns; /* is this clock in nanoseconds? */
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} trace_clocks[] = {
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{ trace_clock_local, "local", 1 },
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{ trace_clock_global, "global", 1 },
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{ trace_clock_counter, "counter", 0 },
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ARCH_TRACE_CLOCKS
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};
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int trace_clock_id;
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|
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/*
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* trace_parser_get_init - gets the buffer for trace parser
|
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*/
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int trace_parser_get_init(struct trace_parser *parser, int size)
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{
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memset(parser, 0, sizeof(*parser));
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parser->buffer = kmalloc(size, GFP_KERNEL);
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if (!parser->buffer)
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return 1;
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parser->size = size;
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return 0;
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}
|
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|
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/*
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* trace_parser_put - frees the buffer for trace parser
|
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*/
|
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void trace_parser_put(struct trace_parser *parser)
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{
|
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kfree(parser->buffer);
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}
|
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|
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/*
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* trace_get_user - reads the user input string separated by space
|
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* (matched by isspace(ch))
|
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*
|
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* For each string found the 'struct trace_parser' is updated,
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* and the function returns.
|
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*
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* Returns number of bytes read.
|
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*
|
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* See kernel/trace/trace.h for 'struct trace_parser' details.
|
|
*/
|
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int trace_get_user(struct trace_parser *parser, const char __user *ubuf,
|
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size_t cnt, loff_t *ppos)
|
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{
|
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char ch;
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size_t read = 0;
|
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ssize_t ret;
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|
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if (!*ppos)
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trace_parser_clear(parser);
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|
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ret = get_user(ch, ubuf++);
|
|
if (ret)
|
|
goto out;
|
|
|
|
read++;
|
|
cnt--;
|
|
|
|
/*
|
|
* The parser is not finished with the last write,
|
|
* continue reading the user input without skipping spaces.
|
|
*/
|
|
if (!parser->cont) {
|
|
/* skip white space */
|
|
while (cnt && isspace(ch)) {
|
|
ret = get_user(ch, ubuf++);
|
|
if (ret)
|
|
goto out;
|
|
read++;
|
|
cnt--;
|
|
}
|
|
|
|
/* only spaces were written */
|
|
if (isspace(ch)) {
|
|
*ppos += read;
|
|
ret = read;
|
|
goto out;
|
|
}
|
|
|
|
parser->idx = 0;
|
|
}
|
|
|
|
/* read the non-space input */
|
|
while (cnt && !isspace(ch)) {
|
|
if (parser->idx < parser->size - 1)
|
|
parser->buffer[parser->idx++] = ch;
|
|
else {
|
|
ret = -EINVAL;
|
|
goto out;
|
|
}
|
|
ret = get_user(ch, ubuf++);
|
|
if (ret)
|
|
goto out;
|
|
read++;
|
|
cnt--;
|
|
}
|
|
|
|
/* We either got finished input or we have to wait for another call. */
|
|
if (isspace(ch)) {
|
|
parser->buffer[parser->idx] = 0;
|
|
parser->cont = false;
|
|
} else {
|
|
parser->cont = true;
|
|
parser->buffer[parser->idx++] = ch;
|
|
}
|
|
|
|
*ppos += read;
|
|
ret = read;
|
|
|
|
out:
|
|
return ret;
|
|
}
|
|
|
|
ssize_t trace_seq_to_user(struct trace_seq *s, char __user *ubuf, size_t cnt)
|
|
{
|
|
int len;
|
|
int ret;
|
|
|
|
if (!cnt)
|
|
return 0;
|
|
|
|
if (s->len <= s->readpos)
|
|
return -EBUSY;
|
|
|
|
len = s->len - s->readpos;
|
|
if (cnt > len)
|
|
cnt = len;
|
|
ret = copy_to_user(ubuf, s->buffer + s->readpos, cnt);
|
|
if (ret == cnt)
|
|
return -EFAULT;
|
|
|
|
cnt -= ret;
|
|
|
|
s->readpos += cnt;
|
|
return cnt;
|
|
}
|
|
|
|
static ssize_t trace_seq_to_buffer(struct trace_seq *s, void *buf, size_t cnt)
|
|
{
|
|
int len;
|
|
|
|
if (s->len <= s->readpos)
|
|
return -EBUSY;
|
|
|
|
len = s->len - s->readpos;
|
|
if (cnt > len)
|
|
cnt = len;
|
|
memcpy(buf, s->buffer + s->readpos, cnt);
|
|
|
|
s->readpos += cnt;
|
|
return cnt;
|
|
}
|
|
|
|
/*
|
|
* ftrace_max_lock is used to protect the swapping of buffers
|
|
* when taking a max snapshot. The buffers themselves are
|
|
* protected by per_cpu spinlocks. But the action of the swap
|
|
* needs its own lock.
|
|
*
|
|
* This is defined as a arch_spinlock_t in order to help
|
|
* with performance when lockdep debugging is enabled.
|
|
*
|
|
* It is also used in other places outside the update_max_tr
|
|
* so it needs to be defined outside of the
|
|
* CONFIG_TRACER_MAX_TRACE.
|
|
*/
|
|
static arch_spinlock_t ftrace_max_lock =
|
|
(arch_spinlock_t)__ARCH_SPIN_LOCK_UNLOCKED;
|
|
|
|
unsigned long __read_mostly tracing_thresh;
|
|
|
|
#ifdef CONFIG_TRACER_MAX_TRACE
|
|
unsigned long __read_mostly tracing_max_latency;
|
|
|
|
/*
|
|
* Copy the new maximum trace into the separate maximum-trace
|
|
* structure. (this way the maximum trace is permanently saved,
|
|
* for later retrieval via /sys/kernel/debug/tracing/latency_trace)
|
|
*/
|
|
static void
|
|
__update_max_tr(struct trace_array *tr, struct task_struct *tsk, int cpu)
|
|
{
|
|
struct trace_array_cpu *data = tr->data[cpu];
|
|
struct trace_array_cpu *max_data;
|
|
|
|
max_tr.cpu = cpu;
|
|
max_tr.time_start = data->preempt_timestamp;
|
|
|
|
max_data = max_tr.data[cpu];
|
|
max_data->saved_latency = tracing_max_latency;
|
|
max_data->critical_start = data->critical_start;
|
|
max_data->critical_end = data->critical_end;
|
|
|
|
memcpy(max_data->comm, tsk->comm, TASK_COMM_LEN);
|
|
max_data->pid = tsk->pid;
|
|
max_data->uid = task_uid(tsk);
|
|
max_data->nice = tsk->static_prio - 20 - MAX_RT_PRIO;
|
|
max_data->policy = tsk->policy;
|
|
max_data->rt_priority = tsk->rt_priority;
|
|
|
|
/* record this tasks comm */
|
|
tracing_record_cmdline(tsk);
|
|
}
|
|
|
|
/**
|
|
* update_max_tr - snapshot all trace buffers from global_trace to max_tr
|
|
* @tr: tracer
|
|
* @tsk: the task with the latency
|
|
* @cpu: The cpu that initiated the trace.
|
|
*
|
|
* Flip the buffers between the @tr and the max_tr and record information
|
|
* about which task was the cause of this latency.
|
|
*/
|
|
void
|
|
update_max_tr(struct trace_array *tr, struct task_struct *tsk, int cpu)
|
|
{
|
|
struct ring_buffer *buf;
|
|
|
|
if (trace_stop_count)
|
|
return;
|
|
|
|
WARN_ON_ONCE(!irqs_disabled());
|
|
|
|
if (!current_trace->allocated_snapshot) {
|
|
/* Only the nop tracer should hit this when disabling */
|
|
WARN_ON_ONCE(current_trace != &nop_trace);
|
|
return;
|
|
}
|
|
|
|
arch_spin_lock(&ftrace_max_lock);
|
|
|
|
buf = tr->buffer;
|
|
tr->buffer = max_tr.buffer;
|
|
max_tr.buffer = buf;
|
|
|
|
__update_max_tr(tr, tsk, cpu);
|
|
arch_spin_unlock(&ftrace_max_lock);
|
|
}
|
|
|
|
/**
|
|
* update_max_tr_single - only copy one trace over, and reset the rest
|
|
* @tr - tracer
|
|
* @tsk - task with the latency
|
|
* @cpu - the cpu of the buffer to copy.
|
|
*
|
|
* Flip the trace of a single CPU buffer between the @tr and the max_tr.
|
|
*/
|
|
void
|
|
update_max_tr_single(struct trace_array *tr, struct task_struct *tsk, int cpu)
|
|
{
|
|
int ret;
|
|
|
|
if (trace_stop_count)
|
|
return;
|
|
|
|
WARN_ON_ONCE(!irqs_disabled());
|
|
if (WARN_ON_ONCE(!current_trace->allocated_snapshot))
|
|
return;
|
|
|
|
arch_spin_lock(&ftrace_max_lock);
|
|
|
|
ret = ring_buffer_swap_cpu(max_tr.buffer, tr->buffer, cpu);
|
|
|
|
if (ret == -EBUSY) {
|
|
/*
|
|
* We failed to swap the buffer due to a commit taking
|
|
* place on this CPU. We fail to record, but we reset
|
|
* the max trace buffer (no one writes directly to it)
|
|
* and flag that it failed.
|
|
*/
|
|
trace_array_printk(&max_tr, _THIS_IP_,
|
|
"Failed to swap buffers due to commit in progress\n");
|
|
}
|
|
|
|
WARN_ON_ONCE(ret && ret != -EAGAIN && ret != -EBUSY);
|
|
|
|
__update_max_tr(tr, tsk, cpu);
|
|
arch_spin_unlock(&ftrace_max_lock);
|
|
}
|
|
#endif /* CONFIG_TRACER_MAX_TRACE */
|
|
|
|
static void default_wait_pipe(struct trace_iterator *iter)
|
|
{
|
|
DEFINE_WAIT(wait);
|
|
|
|
prepare_to_wait(&trace_wait, &wait, TASK_INTERRUPTIBLE);
|
|
|
|
/*
|
|
* The events can happen in critical sections where
|
|
* checking a work queue can cause deadlocks.
|
|
* After adding a task to the queue, this flag is set
|
|
* only to notify events to try to wake up the queue
|
|
* using irq_work.
|
|
*
|
|
* We don't clear it even if the buffer is no longer
|
|
* empty. The flag only causes the next event to run
|
|
* irq_work to do the work queue wake up. The worse
|
|
* that can happen if we race with !trace_empty() is that
|
|
* an event will cause an irq_work to try to wake up
|
|
* an empty queue.
|
|
*
|
|
* There's no reason to protect this flag either, as
|
|
* the work queue and irq_work logic will do the necessary
|
|
* synchronization for the wake ups. The only thing
|
|
* that is necessary is that the wake up happens after
|
|
* a task has been queued. It's OK for spurious wake ups.
|
|
*/
|
|
trace_wakeup_needed = true;
|
|
|
|
if (trace_empty(iter))
|
|
schedule();
|
|
|
|
finish_wait(&trace_wait, &wait);
|
|
}
|
|
|
|
/**
|
|
* register_tracer - register a tracer with the ftrace system.
|
|
* @type - the plugin for the tracer
|
|
*
|
|
* Register a new plugin tracer.
|
|
*/
|
|
int register_tracer(struct tracer *type)
|
|
{
|
|
struct tracer *t;
|
|
int ret = 0;
|
|
|
|
if (!type->name) {
|
|
pr_info("Tracer must have a name\n");
|
|
return -1;
|
|
}
|
|
|
|
if (strlen(type->name) >= MAX_TRACER_SIZE) {
|
|
pr_info("Tracer has a name longer than %d\n", MAX_TRACER_SIZE);
|
|
return -1;
|
|
}
|
|
|
|
mutex_lock(&trace_types_lock);
|
|
|
|
tracing_selftest_running = true;
|
|
|
|
for (t = trace_types; t; t = t->next) {
|
|
if (strcmp(type->name, t->name) == 0) {
|
|
/* already found */
|
|
pr_info("Tracer %s already registered\n",
|
|
type->name);
|
|
ret = -1;
|
|
goto out;
|
|
}
|
|
}
|
|
|
|
if (!type->set_flag)
|
|
type->set_flag = &dummy_set_flag;
|
|
if (!type->flags)
|
|
type->flags = &dummy_tracer_flags;
|
|
else
|
|
if (!type->flags->opts)
|
|
type->flags->opts = dummy_tracer_opt;
|
|
if (!type->wait_pipe)
|
|
type->wait_pipe = default_wait_pipe;
|
|
|
|
|
|
#ifdef CONFIG_FTRACE_STARTUP_TEST
|
|
if (type->selftest && !tracing_selftest_disabled) {
|
|
struct tracer *saved_tracer = current_trace;
|
|
struct trace_array *tr = &global_trace;
|
|
|
|
/*
|
|
* Run a selftest on this tracer.
|
|
* Here we reset the trace buffer, and set the current
|
|
* tracer to be this tracer. The tracer can then run some
|
|
* internal tracing to verify that everything is in order.
|
|
* If we fail, we do not register this tracer.
|
|
*/
|
|
tracing_reset_online_cpus(tr);
|
|
|
|
current_trace = type;
|
|
|
|
if (type->use_max_tr) {
|
|
/* If we expanded the buffers, make sure the max is expanded too */
|
|
if (ring_buffer_expanded)
|
|
ring_buffer_resize(max_tr.buffer, trace_buf_size,
|
|
RING_BUFFER_ALL_CPUS);
|
|
type->allocated_snapshot = true;
|
|
}
|
|
|
|
/* the test is responsible for initializing and enabling */
|
|
pr_info("Testing tracer %s: ", type->name);
|
|
ret = type->selftest(type, tr);
|
|
/* the test is responsible for resetting too */
|
|
current_trace = saved_tracer;
|
|
if (ret) {
|
|
printk(KERN_CONT "FAILED!\n");
|
|
/* Add the warning after printing 'FAILED' */
|
|
WARN_ON(1);
|
|
goto out;
|
|
}
|
|
/* Only reset on passing, to avoid touching corrupted buffers */
|
|
tracing_reset_online_cpus(tr);
|
|
|
|
if (type->use_max_tr) {
|
|
type->allocated_snapshot = false;
|
|
|
|
/* Shrink the max buffer again */
|
|
if (ring_buffer_expanded)
|
|
ring_buffer_resize(max_tr.buffer, 1,
|
|
RING_BUFFER_ALL_CPUS);
|
|
}
|
|
|
|
printk(KERN_CONT "PASSED\n");
|
|
}
|
|
#endif
|
|
|
|
type->next = trace_types;
|
|
trace_types = type;
|
|
|
|
out:
|
|
tracing_selftest_running = false;
|
|
mutex_unlock(&trace_types_lock);
|
|
|
|
if (ret || !default_bootup_tracer)
|
|
goto out_unlock;
|
|
|
|
if (strncmp(default_bootup_tracer, type->name, MAX_TRACER_SIZE))
|
|
goto out_unlock;
|
|
|
|
printk(KERN_INFO "Starting tracer '%s'\n", type->name);
|
|
/* Do we want this tracer to start on bootup? */
|
|
tracing_set_tracer(type->name);
|
|
default_bootup_tracer = NULL;
|
|
/* disable other selftests, since this will break it. */
|
|
tracing_selftest_disabled = 1;
|
|
#ifdef CONFIG_FTRACE_STARTUP_TEST
|
|
printk(KERN_INFO "Disabling FTRACE selftests due to running tracer '%s'\n",
|
|
type->name);
|
|
#endif
|
|
|
|
out_unlock:
|
|
return ret;
|
|
}
|
|
|
|
void tracing_reset(struct trace_array *tr, int cpu)
|
|
{
|
|
struct ring_buffer *buffer = tr->buffer;
|
|
|
|
if (!buffer)
|
|
return;
|
|
|
|
ring_buffer_record_disable(buffer);
|
|
|
|
/* Make sure all commits have finished */
|
|
synchronize_sched();
|
|
ring_buffer_reset_cpu(buffer, cpu);
|
|
|
|
ring_buffer_record_enable(buffer);
|
|
}
|
|
|
|
void tracing_reset_online_cpus(struct trace_array *tr)
|
|
{
|
|
struct ring_buffer *buffer = tr->buffer;
|
|
int cpu;
|
|
|
|
if (!buffer)
|
|
return;
|
|
|
|
ring_buffer_record_disable(buffer);
|
|
|
|
/* Make sure all commits have finished */
|
|
synchronize_sched();
|
|
|
|
tr->time_start = ftrace_now(tr->cpu);
|
|
|
|
for_each_online_cpu(cpu)
|
|
ring_buffer_reset_cpu(buffer, cpu);
|
|
|
|
ring_buffer_record_enable(buffer);
|
|
}
|
|
|
|
void tracing_reset_current(int cpu)
|
|
{
|
|
tracing_reset(&global_trace, cpu);
|
|
}
|
|
|
|
void tracing_reset_current_online_cpus(void)
|
|
{
|
|
tracing_reset_online_cpus(&global_trace);
|
|
}
|
|
|
|
#define SAVED_CMDLINES 128
|
|
#define NO_CMDLINE_MAP UINT_MAX
|
|
static unsigned map_pid_to_cmdline[PID_MAX_DEFAULT+1];
|
|
static unsigned map_cmdline_to_pid[SAVED_CMDLINES];
|
|
static char saved_cmdlines[SAVED_CMDLINES][TASK_COMM_LEN];
|
|
static int cmdline_idx;
|
|
static arch_spinlock_t trace_cmdline_lock = __ARCH_SPIN_LOCK_UNLOCKED;
|
|
|
|
/* temporary disable recording */
|
|
static atomic_t trace_record_cmdline_disabled __read_mostly;
|
|
|
|
static void trace_init_cmdlines(void)
|
|
{
|
|
memset(&map_pid_to_cmdline, NO_CMDLINE_MAP, sizeof(map_pid_to_cmdline));
|
|
memset(&map_cmdline_to_pid, NO_CMDLINE_MAP, sizeof(map_cmdline_to_pid));
|
|
cmdline_idx = 0;
|
|
}
|
|
|
|
int is_tracing_stopped(void)
|
|
{
|
|
return trace_stop_count;
|
|
}
|
|
|
|
/**
|
|
* ftrace_off_permanent - disable all ftrace code permanently
|
|
*
|
|
* This should only be called when a serious anomally has
|
|
* been detected. This will turn off the function tracing,
|
|
* ring buffers, and other tracing utilites. It takes no
|
|
* locks and can be called from any context.
|
|
*/
|
|
void ftrace_off_permanent(void)
|
|
{
|
|
tracing_disabled = 1;
|
|
ftrace_stop();
|
|
tracing_off_permanent();
|
|
}
|
|
|
|
/**
|
|
* tracing_start - quick start of the tracer
|
|
*
|
|
* If tracing is enabled but was stopped by tracing_stop,
|
|
* this will start the tracer back up.
|
|
*/
|
|
void tracing_start(void)
|
|
{
|
|
struct ring_buffer *buffer;
|
|
unsigned long flags;
|
|
|
|
if (tracing_disabled)
|
|
return;
|
|
|
|
raw_spin_lock_irqsave(&tracing_start_lock, flags);
|
|
if (--trace_stop_count) {
|
|
if (trace_stop_count < 0) {
|
|
/* Someone screwed up their debugging */
|
|
WARN_ON_ONCE(1);
|
|
trace_stop_count = 0;
|
|
}
|
|
goto out;
|
|
}
|
|
|
|
/* Prevent the buffers from switching */
|
|
arch_spin_lock(&ftrace_max_lock);
|
|
|
|
buffer = global_trace.buffer;
|
|
if (buffer)
|
|
ring_buffer_record_enable(buffer);
|
|
|
|
buffer = max_tr.buffer;
|
|
if (buffer)
|
|
ring_buffer_record_enable(buffer);
|
|
|
|
arch_spin_unlock(&ftrace_max_lock);
|
|
|
|
ftrace_start();
|
|
out:
|
|
raw_spin_unlock_irqrestore(&tracing_start_lock, flags);
|
|
}
|
|
|
|
/**
|
|
* tracing_stop - quick stop of the tracer
|
|
*
|
|
* Light weight way to stop tracing. Use in conjunction with
|
|
* tracing_start.
|
|
*/
|
|
void tracing_stop(void)
|
|
{
|
|
struct ring_buffer *buffer;
|
|
unsigned long flags;
|
|
|
|
ftrace_stop();
|
|
raw_spin_lock_irqsave(&tracing_start_lock, flags);
|
|
if (trace_stop_count++)
|
|
goto out;
|
|
|
|
/* Prevent the buffers from switching */
|
|
arch_spin_lock(&ftrace_max_lock);
|
|
|
|
buffer = global_trace.buffer;
|
|
if (buffer)
|
|
ring_buffer_record_disable(buffer);
|
|
|
|
buffer = max_tr.buffer;
|
|
if (buffer)
|
|
ring_buffer_record_disable(buffer);
|
|
|
|
arch_spin_unlock(&ftrace_max_lock);
|
|
|
|
out:
|
|
raw_spin_unlock_irqrestore(&tracing_start_lock, flags);
|
|
}
|
|
|
|
void trace_stop_cmdline_recording(void);
|
|
|
|
static void trace_save_cmdline(struct task_struct *tsk)
|
|
{
|
|
unsigned pid, idx;
|
|
|
|
if (!tsk->pid || unlikely(tsk->pid > PID_MAX_DEFAULT))
|
|
return;
|
|
|
|
/*
|
|
* It's not the end of the world if we don't get
|
|
* the lock, but we also don't want to spin
|
|
* nor do we want to disable interrupts,
|
|
* so if we miss here, then better luck next time.
|
|
*/
|
|
if (!arch_spin_trylock(&trace_cmdline_lock))
|
|
return;
|
|
|
|
idx = map_pid_to_cmdline[tsk->pid];
|
|
if (idx == NO_CMDLINE_MAP) {
|
|
idx = (cmdline_idx + 1) % SAVED_CMDLINES;
|
|
|
|
/*
|
|
* Check whether the cmdline buffer at idx has a pid
|
|
* mapped. We are going to overwrite that entry so we
|
|
* need to clear the map_pid_to_cmdline. Otherwise we
|
|
* would read the new comm for the old pid.
|
|
*/
|
|
pid = map_cmdline_to_pid[idx];
|
|
if (pid != NO_CMDLINE_MAP)
|
|
map_pid_to_cmdline[pid] = NO_CMDLINE_MAP;
|
|
|
|
map_cmdline_to_pid[idx] = tsk->pid;
|
|
map_pid_to_cmdline[tsk->pid] = idx;
|
|
|
|
cmdline_idx = idx;
|
|
}
|
|
|
|
memcpy(&saved_cmdlines[idx], tsk->comm, TASK_COMM_LEN);
|
|
|
|
arch_spin_unlock(&trace_cmdline_lock);
|
|
}
|
|
|
|
void trace_find_cmdline(int pid, char comm[])
|
|
{
|
|
unsigned map;
|
|
|
|
if (!pid) {
|
|
strcpy(comm, "<idle>");
|
|
return;
|
|
}
|
|
|
|
if (WARN_ON_ONCE(pid < 0)) {
|
|
strcpy(comm, "<XXX>");
|
|
return;
|
|
}
|
|
|
|
if (pid > PID_MAX_DEFAULT) {
|
|
strcpy(comm, "<...>");
|
|
return;
|
|
}
|
|
|
|
preempt_disable();
|
|
arch_spin_lock(&trace_cmdline_lock);
|
|
map = map_pid_to_cmdline[pid];
|
|
if (map != NO_CMDLINE_MAP)
|
|
strcpy(comm, saved_cmdlines[map]);
|
|
else
|
|
strcpy(comm, "<...>");
|
|
|
|
arch_spin_unlock(&trace_cmdline_lock);
|
|
preempt_enable();
|
|
}
|
|
|
|
void tracing_record_cmdline(struct task_struct *tsk)
|
|
{
|
|
if (atomic_read(&trace_record_cmdline_disabled) || !tracing_is_on())
|
|
return;
|
|
|
|
if (!__this_cpu_read(trace_cmdline_save))
|
|
return;
|
|
|
|
__this_cpu_write(trace_cmdline_save, false);
|
|
|
|
trace_save_cmdline(tsk);
|
|
}
|
|
|
|
void
|
|
tracing_generic_entry_update(struct trace_entry *entry, unsigned long flags,
|
|
int pc)
|
|
{
|
|
struct task_struct *tsk = current;
|
|
|
|
entry->preempt_count = pc & 0xff;
|
|
entry->pid = (tsk) ? tsk->pid : 0;
|
|
entry->flags =
|
|
#ifdef CONFIG_TRACE_IRQFLAGS_SUPPORT
|
|
(irqs_disabled_flags(flags) ? TRACE_FLAG_IRQS_OFF : 0) |
|
|
#else
|
|
TRACE_FLAG_IRQS_NOSUPPORT |
|
|
#endif
|
|
((pc & HARDIRQ_MASK) ? TRACE_FLAG_HARDIRQ : 0) |
|
|
((pc & SOFTIRQ_MASK) ? TRACE_FLAG_SOFTIRQ : 0) |
|
|
(need_resched() ? TRACE_FLAG_NEED_RESCHED : 0);
|
|
}
|
|
EXPORT_SYMBOL_GPL(tracing_generic_entry_update);
|
|
|
|
struct ring_buffer_event *
|
|
trace_buffer_lock_reserve(struct ring_buffer *buffer,
|
|
int type,
|
|
unsigned long len,
|
|
unsigned long flags, int pc)
|
|
{
|
|
struct ring_buffer_event *event;
|
|
|
|
event = ring_buffer_lock_reserve(buffer, len);
|
|
if (event != NULL) {
|
|
struct trace_entry *ent = ring_buffer_event_data(event);
|
|
|
|
tracing_generic_entry_update(ent, flags, pc);
|
|
ent->type = type;
|
|
}
|
|
|
|
return event;
|
|
}
|
|
|
|
void
|
|
__buffer_unlock_commit(struct ring_buffer *buffer, struct ring_buffer_event *event)
|
|
{
|
|
__this_cpu_write(trace_cmdline_save, true);
|
|
if (trace_wakeup_needed) {
|
|
trace_wakeup_needed = false;
|
|
/* irq_work_queue() supplies it's own memory barriers */
|
|
irq_work_queue(&trace_work_wakeup);
|
|
}
|
|
ring_buffer_unlock_commit(buffer, event);
|
|
}
|
|
|
|
static inline void
|
|
__trace_buffer_unlock_commit(struct ring_buffer *buffer,
|
|
struct ring_buffer_event *event,
|
|
unsigned long flags, int pc)
|
|
{
|
|
__buffer_unlock_commit(buffer, event);
|
|
|
|
ftrace_trace_stack(buffer, flags, 6, pc);
|
|
ftrace_trace_userstack(buffer, flags, pc);
|
|
}
|
|
|
|
void trace_buffer_unlock_commit(struct ring_buffer *buffer,
|
|
struct ring_buffer_event *event,
|
|
unsigned long flags, int pc)
|
|
{
|
|
__trace_buffer_unlock_commit(buffer, event, flags, pc);
|
|
}
|
|
EXPORT_SYMBOL_GPL(trace_buffer_unlock_commit);
|
|
|
|
struct ring_buffer_event *
|
|
trace_current_buffer_lock_reserve(struct ring_buffer **current_rb,
|
|
int type, unsigned long len,
|
|
unsigned long flags, int pc)
|
|
{
|
|
*current_rb = global_trace.buffer;
|
|
return trace_buffer_lock_reserve(*current_rb,
|
|
type, len, flags, pc);
|
|
}
|
|
EXPORT_SYMBOL_GPL(trace_current_buffer_lock_reserve);
|
|
|
|
void trace_current_buffer_unlock_commit(struct ring_buffer *buffer,
|
|
struct ring_buffer_event *event,
|
|
unsigned long flags, int pc)
|
|
{
|
|
__trace_buffer_unlock_commit(buffer, event, flags, pc);
|
|
}
|
|
EXPORT_SYMBOL_GPL(trace_current_buffer_unlock_commit);
|
|
|
|
void trace_buffer_unlock_commit_regs(struct ring_buffer *buffer,
|
|
struct ring_buffer_event *event,
|
|
unsigned long flags, int pc,
|
|
struct pt_regs *regs)
|
|
{
|
|
__buffer_unlock_commit(buffer, event);
|
|
|
|
ftrace_trace_stack_regs(buffer, flags, 0, pc, regs);
|
|
ftrace_trace_userstack(buffer, flags, pc);
|
|
}
|
|
EXPORT_SYMBOL_GPL(trace_buffer_unlock_commit_regs);
|
|
|
|
void trace_current_buffer_discard_commit(struct ring_buffer *buffer,
|
|
struct ring_buffer_event *event)
|
|
{
|
|
ring_buffer_discard_commit(buffer, event);
|
|
}
|
|
EXPORT_SYMBOL_GPL(trace_current_buffer_discard_commit);
|
|
|
|
void
|
|
trace_function(struct trace_array *tr,
|
|
unsigned long ip, unsigned long parent_ip, unsigned long flags,
|
|
int pc)
|
|
{
|
|
struct ftrace_event_call *call = &event_function;
|
|
struct ring_buffer *buffer = tr->buffer;
|
|
struct ring_buffer_event *event;
|
|
struct ftrace_entry *entry;
|
|
|
|
/* If we are reading the ring buffer, don't trace */
|
|
if (unlikely(__this_cpu_read(ftrace_cpu_disabled)))
|
|
return;
|
|
|
|
event = trace_buffer_lock_reserve(buffer, TRACE_FN, sizeof(*entry),
|
|
flags, pc);
|
|
if (!event)
|
|
return;
|
|
entry = ring_buffer_event_data(event);
|
|
entry->ip = ip;
|
|
entry->parent_ip = parent_ip;
|
|
|
|
if (!filter_check_discard(call, entry, buffer, event))
|
|
__buffer_unlock_commit(buffer, event);
|
|
}
|
|
|
|
void
|
|
ftrace(struct trace_array *tr, struct trace_array_cpu *data,
|
|
unsigned long ip, unsigned long parent_ip, unsigned long flags,
|
|
int pc)
|
|
{
|
|
if (likely(!atomic_read(&data->disabled)))
|
|
trace_function(tr, ip, parent_ip, flags, pc);
|
|
}
|
|
|
|
#ifdef CONFIG_STACKTRACE
|
|
|
|
#define FTRACE_STACK_MAX_ENTRIES (PAGE_SIZE / sizeof(unsigned long))
|
|
struct ftrace_stack {
|
|
unsigned long calls[FTRACE_STACK_MAX_ENTRIES];
|
|
};
|
|
|
|
static DEFINE_PER_CPU(struct ftrace_stack, ftrace_stack);
|
|
static DEFINE_PER_CPU(int, ftrace_stack_reserve);
|
|
|
|
static void __ftrace_trace_stack(struct ring_buffer *buffer,
|
|
unsigned long flags,
|
|
int skip, int pc, struct pt_regs *regs)
|
|
{
|
|
struct ftrace_event_call *call = &event_kernel_stack;
|
|
struct ring_buffer_event *event;
|
|
struct stack_entry *entry;
|
|
struct stack_trace trace;
|
|
int use_stack;
|
|
int size = FTRACE_STACK_ENTRIES;
|
|
|
|
trace.nr_entries = 0;
|
|
trace.skip = skip;
|
|
|
|
/*
|
|
* Since events can happen in NMIs there's no safe way to
|
|
* use the per cpu ftrace_stacks. We reserve it and if an interrupt
|
|
* or NMI comes in, it will just have to use the default
|
|
* FTRACE_STACK_SIZE.
|
|
*/
|
|
preempt_disable_notrace();
|
|
|
|
use_stack = __this_cpu_inc_return(ftrace_stack_reserve);
|
|
/*
|
|
* We don't need any atomic variables, just a barrier.
|
|
* If an interrupt comes in, we don't care, because it would
|
|
* have exited and put the counter back to what we want.
|
|
* We just need a barrier to keep gcc from moving things
|
|
* around.
|
|
*/
|
|
barrier();
|
|
if (use_stack == 1) {
|
|
trace.entries = &__get_cpu_var(ftrace_stack).calls[0];
|
|
trace.max_entries = FTRACE_STACK_MAX_ENTRIES;
|
|
|
|
if (regs)
|
|
save_stack_trace_regs(regs, &trace);
|
|
else
|
|
save_stack_trace(&trace);
|
|
|
|
if (trace.nr_entries > size)
|
|
size = trace.nr_entries;
|
|
} else
|
|
/* From now on, use_stack is a boolean */
|
|
use_stack = 0;
|
|
|
|
size *= sizeof(unsigned long);
|
|
|
|
event = trace_buffer_lock_reserve(buffer, TRACE_STACK,
|
|
sizeof(*entry) + size, flags, pc);
|
|
if (!event)
|
|
goto out;
|
|
entry = ring_buffer_event_data(event);
|
|
|
|
memset(&entry->caller, 0, size);
|
|
|
|
if (use_stack)
|
|
memcpy(&entry->caller, trace.entries,
|
|
trace.nr_entries * sizeof(unsigned long));
|
|
else {
|
|
trace.max_entries = FTRACE_STACK_ENTRIES;
|
|
trace.entries = entry->caller;
|
|
if (regs)
|
|
save_stack_trace_regs(regs, &trace);
|
|
else
|
|
save_stack_trace(&trace);
|
|
}
|
|
|
|
entry->size = trace.nr_entries;
|
|
|
|
if (!filter_check_discard(call, entry, buffer, event))
|
|
__buffer_unlock_commit(buffer, event);
|
|
|
|
out:
|
|
/* Again, don't let gcc optimize things here */
|
|
barrier();
|
|
__this_cpu_dec(ftrace_stack_reserve);
|
|
preempt_enable_notrace();
|
|
|
|
}
|
|
|
|
void ftrace_trace_stack_regs(struct ring_buffer *buffer, unsigned long flags,
|
|
int skip, int pc, struct pt_regs *regs)
|
|
{
|
|
if (!(trace_flags & TRACE_ITER_STACKTRACE))
|
|
return;
|
|
|
|
__ftrace_trace_stack(buffer, flags, skip, pc, regs);
|
|
}
|
|
|
|
void ftrace_trace_stack(struct ring_buffer *buffer, unsigned long flags,
|
|
int skip, int pc)
|
|
{
|
|
if (!(trace_flags & TRACE_ITER_STACKTRACE))
|
|
return;
|
|
|
|
__ftrace_trace_stack(buffer, flags, skip, pc, NULL);
|
|
}
|
|
|
|
void __trace_stack(struct trace_array *tr, unsigned long flags, int skip,
|
|
int pc)
|
|
{
|
|
__ftrace_trace_stack(tr->buffer, flags, skip, pc, NULL);
|
|
}
|
|
|
|
/**
|
|
* trace_dump_stack - record a stack back trace in the trace buffer
|
|
*/
|
|
void trace_dump_stack(void)
|
|
{
|
|
unsigned long flags;
|
|
|
|
if (tracing_disabled || tracing_selftest_running)
|
|
return;
|
|
|
|
local_save_flags(flags);
|
|
|
|
/* skipping 3 traces, seems to get us at the caller of this function */
|
|
__ftrace_trace_stack(global_trace.buffer, flags, 3, preempt_count(), NULL);
|
|
}
|
|
|
|
static DEFINE_PER_CPU(int, user_stack_count);
|
|
|
|
void
|
|
ftrace_trace_userstack(struct ring_buffer *buffer, unsigned long flags, int pc)
|
|
{
|
|
struct ftrace_event_call *call = &event_user_stack;
|
|
struct ring_buffer_event *event;
|
|
struct userstack_entry *entry;
|
|
struct stack_trace trace;
|
|
|
|
if (!(trace_flags & TRACE_ITER_USERSTACKTRACE))
|
|
return;
|
|
|
|
/*
|
|
* NMIs can not handle page faults, even with fix ups.
|
|
* The save user stack can (and often does) fault.
|
|
*/
|
|
if (unlikely(in_nmi()))
|
|
return;
|
|
|
|
/*
|
|
* prevent recursion, since the user stack tracing may
|
|
* trigger other kernel events.
|
|
*/
|
|
preempt_disable();
|
|
if (__this_cpu_read(user_stack_count))
|
|
goto out;
|
|
|
|
__this_cpu_inc(user_stack_count);
|
|
|
|
event = trace_buffer_lock_reserve(buffer, TRACE_USER_STACK,
|
|
sizeof(*entry), flags, pc);
|
|
if (!event)
|
|
goto out_drop_count;
|
|
entry = ring_buffer_event_data(event);
|
|
|
|
entry->tgid = current->tgid;
|
|
memset(&entry->caller, 0, sizeof(entry->caller));
|
|
|
|
trace.nr_entries = 0;
|
|
trace.max_entries = FTRACE_STACK_ENTRIES;
|
|
trace.skip = 0;
|
|
trace.entries = entry->caller;
|
|
|
|
save_stack_trace_user(&trace);
|
|
if (!filter_check_discard(call, entry, buffer, event))
|
|
__buffer_unlock_commit(buffer, event);
|
|
|
|
out_drop_count:
|
|
__this_cpu_dec(user_stack_count);
|
|
out:
|
|
preempt_enable();
|
|
}
|
|
|
|
#ifdef UNUSED
|
|
static void __trace_userstack(struct trace_array *tr, unsigned long flags)
|
|
{
|
|
ftrace_trace_userstack(tr, flags, preempt_count());
|
|
}
|
|
#endif /* UNUSED */
|
|
|
|
#endif /* CONFIG_STACKTRACE */
|
|
|
|
/* created for use with alloc_percpu */
|
|
struct trace_buffer_struct {
|
|
char buffer[TRACE_BUF_SIZE];
|
|
};
|
|
|
|
static struct trace_buffer_struct *trace_percpu_buffer;
|
|
static struct trace_buffer_struct *trace_percpu_sirq_buffer;
|
|
static struct trace_buffer_struct *trace_percpu_irq_buffer;
|
|
static struct trace_buffer_struct *trace_percpu_nmi_buffer;
|
|
|
|
/*
|
|
* The buffer used is dependent on the context. There is a per cpu
|
|
* buffer for normal context, softirq contex, hard irq context and
|
|
* for NMI context. Thise allows for lockless recording.
|
|
*
|
|
* Note, if the buffers failed to be allocated, then this returns NULL
|
|
*/
|
|
static char *get_trace_buf(void)
|
|
{
|
|
struct trace_buffer_struct *percpu_buffer;
|
|
|
|
/*
|
|
* If we have allocated per cpu buffers, then we do not
|
|
* need to do any locking.
|
|
*/
|
|
if (in_nmi())
|
|
percpu_buffer = trace_percpu_nmi_buffer;
|
|
else if (in_irq())
|
|
percpu_buffer = trace_percpu_irq_buffer;
|
|
else if (in_softirq())
|
|
percpu_buffer = trace_percpu_sirq_buffer;
|
|
else
|
|
percpu_buffer = trace_percpu_buffer;
|
|
|
|
if (!percpu_buffer)
|
|
return NULL;
|
|
|
|
return this_cpu_ptr(&percpu_buffer->buffer[0]);
|
|
}
|
|
|
|
static int alloc_percpu_trace_buffer(void)
|
|
{
|
|
struct trace_buffer_struct *buffers;
|
|
struct trace_buffer_struct *sirq_buffers;
|
|
struct trace_buffer_struct *irq_buffers;
|
|
struct trace_buffer_struct *nmi_buffers;
|
|
|
|
buffers = alloc_percpu(struct trace_buffer_struct);
|
|
if (!buffers)
|
|
goto err_warn;
|
|
|
|
sirq_buffers = alloc_percpu(struct trace_buffer_struct);
|
|
if (!sirq_buffers)
|
|
goto err_sirq;
|
|
|
|
irq_buffers = alloc_percpu(struct trace_buffer_struct);
|
|
if (!irq_buffers)
|
|
goto err_irq;
|
|
|
|
nmi_buffers = alloc_percpu(struct trace_buffer_struct);
|
|
if (!nmi_buffers)
|
|
goto err_nmi;
|
|
|
|
trace_percpu_buffer = buffers;
|
|
trace_percpu_sirq_buffer = sirq_buffers;
|
|
trace_percpu_irq_buffer = irq_buffers;
|
|
trace_percpu_nmi_buffer = nmi_buffers;
|
|
|
|
return 0;
|
|
|
|
err_nmi:
|
|
free_percpu(irq_buffers);
|
|
err_irq:
|
|
free_percpu(sirq_buffers);
|
|
err_sirq:
|
|
free_percpu(buffers);
|
|
err_warn:
|
|
WARN(1, "Could not allocate percpu trace_printk buffer");
|
|
return -ENOMEM;
|
|
}
|
|
|
|
static int buffers_allocated;
|
|
|
|
void trace_printk_init_buffers(void)
|
|
{
|
|
if (buffers_allocated)
|
|
return;
|
|
|
|
if (alloc_percpu_trace_buffer())
|
|
return;
|
|
|
|
pr_info("ftrace: Allocated trace_printk buffers\n");
|
|
|
|
/* Expand the buffers to set size */
|
|
tracing_update_buffers();
|
|
|
|
buffers_allocated = 1;
|
|
|
|
/*
|
|
* trace_printk_init_buffers() can be called by modules.
|
|
* If that happens, then we need to start cmdline recording
|
|
* directly here. If the global_trace.buffer is already
|
|
* allocated here, then this was called by module code.
|
|
*/
|
|
if (global_trace.buffer)
|
|
tracing_start_cmdline_record();
|
|
}
|
|
|
|
void trace_printk_start_comm(void)
|
|
{
|
|
/* Start tracing comms if trace printk is set */
|
|
if (!buffers_allocated)
|
|
return;
|
|
tracing_start_cmdline_record();
|
|
}
|
|
|
|
static void trace_printk_start_stop_comm(int enabled)
|
|
{
|
|
if (!buffers_allocated)
|
|
return;
|
|
|
|
if (enabled)
|
|
tracing_start_cmdline_record();
|
|
else
|
|
tracing_stop_cmdline_record();
|
|
}
|
|
|
|
/**
|
|
* trace_vbprintk - write binary msg to tracing buffer
|
|
*
|
|
*/
|
|
int trace_vbprintk(unsigned long ip, const char *fmt, va_list args)
|
|
{
|
|
struct ftrace_event_call *call = &event_bprint;
|
|
struct ring_buffer_event *event;
|
|
struct ring_buffer *buffer;
|
|
struct trace_array *tr = &global_trace;
|
|
struct bprint_entry *entry;
|
|
unsigned long flags;
|
|
char *tbuffer;
|
|
int len = 0, size, pc;
|
|
|
|
if (unlikely(tracing_selftest_running || tracing_disabled))
|
|
return 0;
|
|
|
|
/* Don't pollute graph traces with trace_vprintk internals */
|
|
pause_graph_tracing();
|
|
|
|
pc = preempt_count();
|
|
preempt_disable_notrace();
|
|
|
|
tbuffer = get_trace_buf();
|
|
if (!tbuffer) {
|
|
len = 0;
|
|
goto out;
|
|
}
|
|
|
|
len = vbin_printf((u32 *)tbuffer, TRACE_BUF_SIZE/sizeof(int), fmt, args);
|
|
|
|
if (len > TRACE_BUF_SIZE/sizeof(int) || len < 0)
|
|
goto out;
|
|
|
|
local_save_flags(flags);
|
|
size = sizeof(*entry) + sizeof(u32) * len;
|
|
buffer = tr->buffer;
|
|
event = trace_buffer_lock_reserve(buffer, TRACE_BPRINT, size,
|
|
flags, pc);
|
|
if (!event)
|
|
goto out;
|
|
entry = ring_buffer_event_data(event);
|
|
entry->ip = ip;
|
|
entry->fmt = fmt;
|
|
|
|
memcpy(entry->buf, tbuffer, sizeof(u32) * len);
|
|
if (!filter_check_discard(call, entry, buffer, event)) {
|
|
__buffer_unlock_commit(buffer, event);
|
|
ftrace_trace_stack(buffer, flags, 6, pc);
|
|
}
|
|
|
|
out:
|
|
preempt_enable_notrace();
|
|
unpause_graph_tracing();
|
|
|
|
return len;
|
|
}
|
|
EXPORT_SYMBOL_GPL(trace_vbprintk);
|
|
|
|
int trace_array_printk(struct trace_array *tr,
|
|
unsigned long ip, const char *fmt, ...)
|
|
{
|
|
int ret;
|
|
va_list ap;
|
|
|
|
if (!(trace_flags & TRACE_ITER_PRINTK))
|
|
return 0;
|
|
|
|
va_start(ap, fmt);
|
|
ret = trace_array_vprintk(tr, ip, fmt, ap);
|
|
va_end(ap);
|
|
return ret;
|
|
}
|
|
|
|
int trace_array_vprintk(struct trace_array *tr,
|
|
unsigned long ip, const char *fmt, va_list args)
|
|
{
|
|
struct ftrace_event_call *call = &event_print;
|
|
struct ring_buffer_event *event;
|
|
struct ring_buffer *buffer;
|
|
int len = 0, size, pc;
|
|
struct print_entry *entry;
|
|
unsigned long flags;
|
|
char *tbuffer;
|
|
|
|
if (tracing_disabled || tracing_selftest_running)
|
|
return 0;
|
|
|
|
/* Don't pollute graph traces with trace_vprintk internals */
|
|
pause_graph_tracing();
|
|
|
|
pc = preempt_count();
|
|
preempt_disable_notrace();
|
|
|
|
|
|
tbuffer = get_trace_buf();
|
|
if (!tbuffer) {
|
|
len = 0;
|
|
goto out;
|
|
}
|
|
|
|
len = vsnprintf(tbuffer, TRACE_BUF_SIZE, fmt, args);
|
|
if (len > TRACE_BUF_SIZE)
|
|
goto out;
|
|
|
|
local_save_flags(flags);
|
|
size = sizeof(*entry) + len + 1;
|
|
buffer = tr->buffer;
|
|
event = trace_buffer_lock_reserve(buffer, TRACE_PRINT, size,
|
|
flags, pc);
|
|
if (!event)
|
|
goto out;
|
|
entry = ring_buffer_event_data(event);
|
|
entry->ip = ip;
|
|
|
|
memcpy(&entry->buf, tbuffer, len);
|
|
entry->buf[len] = '\0';
|
|
if (!filter_check_discard(call, entry, buffer, event)) {
|
|
__buffer_unlock_commit(buffer, event);
|
|
ftrace_trace_stack(buffer, flags, 6, pc);
|
|
}
|
|
out:
|
|
preempt_enable_notrace();
|
|
unpause_graph_tracing();
|
|
|
|
return len;
|
|
}
|
|
|
|
int trace_vprintk(unsigned long ip, const char *fmt, va_list args)
|
|
{
|
|
return trace_array_vprintk(&global_trace, ip, fmt, args);
|
|
}
|
|
EXPORT_SYMBOL_GPL(trace_vprintk);
|
|
|
|
static void trace_iterator_increment(struct trace_iterator *iter)
|
|
{
|
|
struct ring_buffer_iter *buf_iter = trace_buffer_iter(iter, iter->cpu);
|
|
|
|
iter->idx++;
|
|
if (buf_iter)
|
|
ring_buffer_read(buf_iter, NULL);
|
|
}
|
|
|
|
static struct trace_entry *
|
|
peek_next_entry(struct trace_iterator *iter, int cpu, u64 *ts,
|
|
unsigned long *lost_events)
|
|
{
|
|
struct ring_buffer_event *event;
|
|
struct ring_buffer_iter *buf_iter = trace_buffer_iter(iter, cpu);
|
|
|
|
if (buf_iter)
|
|
event = ring_buffer_iter_peek(buf_iter, ts);
|
|
else
|
|
event = ring_buffer_peek(iter->tr->buffer, cpu, ts,
|
|
lost_events);
|
|
|
|
if (event) {
|
|
iter->ent_size = ring_buffer_event_length(event);
|
|
return ring_buffer_event_data(event);
|
|
}
|
|
iter->ent_size = 0;
|
|
return NULL;
|
|
}
|
|
|
|
static struct trace_entry *
|
|
__find_next_entry(struct trace_iterator *iter, int *ent_cpu,
|
|
unsigned long *missing_events, u64 *ent_ts)
|
|
{
|
|
struct ring_buffer *buffer = iter->tr->buffer;
|
|
struct trace_entry *ent, *next = NULL;
|
|
unsigned long lost_events = 0, next_lost = 0;
|
|
int cpu_file = iter->cpu_file;
|
|
u64 next_ts = 0, ts;
|
|
int next_cpu = -1;
|
|
int next_size = 0;
|
|
int cpu;
|
|
|
|
/*
|
|
* If we are in a per_cpu trace file, don't bother by iterating over
|
|
* all cpu and peek directly.
|
|
*/
|
|
if (cpu_file > TRACE_PIPE_ALL_CPU) {
|
|
if (ring_buffer_empty_cpu(buffer, cpu_file))
|
|
return NULL;
|
|
ent = peek_next_entry(iter, cpu_file, ent_ts, missing_events);
|
|
if (ent_cpu)
|
|
*ent_cpu = cpu_file;
|
|
|
|
return ent;
|
|
}
|
|
|
|
for_each_tracing_cpu(cpu) {
|
|
|
|
if (ring_buffer_empty_cpu(buffer, cpu))
|
|
continue;
|
|
|
|
ent = peek_next_entry(iter, cpu, &ts, &lost_events);
|
|
|
|
/*
|
|
* Pick the entry with the smallest timestamp:
|
|
*/
|
|
if (ent && (!next || ts < next_ts)) {
|
|
next = ent;
|
|
next_cpu = cpu;
|
|
next_ts = ts;
|
|
next_lost = lost_events;
|
|
next_size = iter->ent_size;
|
|
}
|
|
}
|
|
|
|
iter->ent_size = next_size;
|
|
|
|
if (ent_cpu)
|
|
*ent_cpu = next_cpu;
|
|
|
|
if (ent_ts)
|
|
*ent_ts = next_ts;
|
|
|
|
if (missing_events)
|
|
*missing_events = next_lost;
|
|
|
|
return next;
|
|
}
|
|
|
|
/* Find the next real entry, without updating the iterator itself */
|
|
struct trace_entry *trace_find_next_entry(struct trace_iterator *iter,
|
|
int *ent_cpu, u64 *ent_ts)
|
|
{
|
|
return __find_next_entry(iter, ent_cpu, NULL, ent_ts);
|
|
}
|
|
|
|
/* Find the next real entry, and increment the iterator to the next entry */
|
|
void *trace_find_next_entry_inc(struct trace_iterator *iter)
|
|
{
|
|
iter->ent = __find_next_entry(iter, &iter->cpu,
|
|
&iter->lost_events, &iter->ts);
|
|
|
|
if (iter->ent)
|
|
trace_iterator_increment(iter);
|
|
|
|
return iter->ent ? iter : NULL;
|
|
}
|
|
|
|
static void trace_consume(struct trace_iterator *iter)
|
|
{
|
|
ring_buffer_consume(iter->tr->buffer, iter->cpu, &iter->ts,
|
|
&iter->lost_events);
|
|
}
|
|
|
|
static void *s_next(struct seq_file *m, void *v, loff_t *pos)
|
|
{
|
|
struct trace_iterator *iter = m->private;
|
|
int i = (int)*pos;
|
|
void *ent;
|
|
|
|
WARN_ON_ONCE(iter->leftover);
|
|
|
|
(*pos)++;
|
|
|
|
/* can't go backwards */
|
|
if (iter->idx > i)
|
|
return NULL;
|
|
|
|
if (iter->idx < 0)
|
|
ent = trace_find_next_entry_inc(iter);
|
|
else
|
|
ent = iter;
|
|
|
|
while (ent && iter->idx < i)
|
|
ent = trace_find_next_entry_inc(iter);
|
|
|
|
iter->pos = *pos;
|
|
|
|
return ent;
|
|
}
|
|
|
|
void tracing_iter_reset(struct trace_iterator *iter, int cpu)
|
|
{
|
|
struct trace_array *tr = iter->tr;
|
|
struct ring_buffer_event *event;
|
|
struct ring_buffer_iter *buf_iter;
|
|
unsigned long entries = 0;
|
|
u64 ts;
|
|
|
|
tr->data[cpu]->skipped_entries = 0;
|
|
|
|
buf_iter = trace_buffer_iter(iter, cpu);
|
|
if (!buf_iter)
|
|
return;
|
|
|
|
ring_buffer_iter_reset(buf_iter);
|
|
|
|
/*
|
|
* We could have the case with the max latency tracers
|
|
* that a reset never took place on a cpu. This is evident
|
|
* by the timestamp being before the start of the buffer.
|
|
*/
|
|
while ((event = ring_buffer_iter_peek(buf_iter, &ts))) {
|
|
if (ts >= iter->tr->time_start)
|
|
break;
|
|
entries++;
|
|
ring_buffer_read(buf_iter, NULL);
|
|
}
|
|
|
|
tr->data[cpu]->skipped_entries = entries;
|
|
}
|
|
|
|
/*
|
|
* The current tracer is copied to avoid a global locking
|
|
* all around.
|
|
*/
|
|
static void *s_start(struct seq_file *m, loff_t *pos)
|
|
{
|
|
struct trace_iterator *iter = m->private;
|
|
int cpu_file = iter->cpu_file;
|
|
void *p = NULL;
|
|
loff_t l = 0;
|
|
int cpu;
|
|
|
|
/*
|
|
* copy the tracer to avoid using a global lock all around.
|
|
* iter->trace is a copy of current_trace, the pointer to the
|
|
* name may be used instead of a strcmp(), as iter->trace->name
|
|
* will point to the same string as current_trace->name.
|
|
*/
|
|
mutex_lock(&trace_types_lock);
|
|
if (unlikely(current_trace && iter->trace->name != current_trace->name))
|
|
*iter->trace = *current_trace;
|
|
mutex_unlock(&trace_types_lock);
|
|
|
|
if (iter->snapshot && iter->trace->use_max_tr)
|
|
return ERR_PTR(-EBUSY);
|
|
|
|
if (!iter->snapshot)
|
|
atomic_inc(&trace_record_cmdline_disabled);
|
|
|
|
if (*pos != iter->pos) {
|
|
iter->ent = NULL;
|
|
iter->cpu = 0;
|
|
iter->idx = -1;
|
|
|
|
if (cpu_file == TRACE_PIPE_ALL_CPU) {
|
|
for_each_tracing_cpu(cpu)
|
|
tracing_iter_reset(iter, cpu);
|
|
} else
|
|
tracing_iter_reset(iter, cpu_file);
|
|
|
|
iter->leftover = 0;
|
|
for (p = iter; p && l < *pos; p = s_next(m, p, &l))
|
|
;
|
|
|
|
} else {
|
|
/*
|
|
* If we overflowed the seq_file before, then we want
|
|
* to just reuse the trace_seq buffer again.
|
|
*/
|
|
if (iter->leftover)
|
|
p = iter;
|
|
else {
|
|
l = *pos - 1;
|
|
p = s_next(m, p, &l);
|
|
}
|
|
}
|
|
|
|
trace_event_read_lock();
|
|
trace_access_lock(cpu_file);
|
|
return p;
|
|
}
|
|
|
|
static void s_stop(struct seq_file *m, void *p)
|
|
{
|
|
struct trace_iterator *iter = m->private;
|
|
|
|
if (iter->snapshot && iter->trace->use_max_tr)
|
|
return;
|
|
|
|
if (!iter->snapshot)
|
|
atomic_dec(&trace_record_cmdline_disabled);
|
|
trace_access_unlock(iter->cpu_file);
|
|
trace_event_read_unlock();
|
|
}
|
|
|
|
static void
|
|
get_total_entries(struct trace_array *tr, unsigned long *total, unsigned long *entries)
|
|
{
|
|
unsigned long count;
|
|
int cpu;
|
|
|
|
*total = 0;
|
|
*entries = 0;
|
|
|
|
for_each_tracing_cpu(cpu) {
|
|
count = ring_buffer_entries_cpu(tr->buffer, cpu);
|
|
/*
|
|
* If this buffer has skipped entries, then we hold all
|
|
* entries for the trace and we need to ignore the
|
|
* ones before the time stamp.
|
|
*/
|
|
if (tr->data[cpu]->skipped_entries) {
|
|
count -= tr->data[cpu]->skipped_entries;
|
|
/* total is the same as the entries */
|
|
*total += count;
|
|
} else
|
|
*total += count +
|
|
ring_buffer_overrun_cpu(tr->buffer, cpu);
|
|
*entries += count;
|
|
}
|
|
}
|
|
|
|
static void print_lat_help_header(struct seq_file *m)
|
|
{
|
|
seq_puts(m, "# _------=> CPU# \n");
|
|
seq_puts(m, "# / _-----=> irqs-off \n");
|
|
seq_puts(m, "# | / _----=> need-resched \n");
|
|
seq_puts(m, "# || / _---=> hardirq/softirq \n");
|
|
seq_puts(m, "# ||| / _--=> preempt-depth \n");
|
|
seq_puts(m, "# |||| / delay \n");
|
|
seq_puts(m, "# cmd pid ||||| time | caller \n");
|
|
seq_puts(m, "# \\ / ||||| \\ | / \n");
|
|
}
|
|
|
|
static void print_event_info(struct trace_array *tr, struct seq_file *m)
|
|
{
|
|
unsigned long total;
|
|
unsigned long entries;
|
|
|
|
get_total_entries(tr, &total, &entries);
|
|
seq_printf(m, "# entries-in-buffer/entries-written: %lu/%lu #P:%d\n",
|
|
entries, total, num_online_cpus());
|
|
seq_puts(m, "#\n");
|
|
}
|
|
|
|
static void print_func_help_header(struct trace_array *tr, struct seq_file *m)
|
|
{
|
|
print_event_info(tr, m);
|
|
seq_puts(m, "# TASK-PID CPU# TIMESTAMP FUNCTION\n");
|
|
seq_puts(m, "# | | | | |\n");
|
|
}
|
|
|
|
static void print_func_help_header_irq(struct trace_array *tr, struct seq_file *m)
|
|
{
|
|
print_event_info(tr, m);
|
|
seq_puts(m, "# _-----=> irqs-off\n");
|
|
seq_puts(m, "# / _----=> need-resched\n");
|
|
seq_puts(m, "# | / _---=> hardirq/softirq\n");
|
|
seq_puts(m, "# || / _--=> preempt-depth\n");
|
|
seq_puts(m, "# ||| / delay\n");
|
|
seq_puts(m, "# TASK-PID CPU# |||| TIMESTAMP FUNCTION\n");
|
|
seq_puts(m, "# | | | |||| | |\n");
|
|
}
|
|
|
|
void
|
|
print_trace_header(struct seq_file *m, struct trace_iterator *iter)
|
|
{
|
|
unsigned long sym_flags = (trace_flags & TRACE_ITER_SYM_MASK);
|
|
struct trace_array *tr = iter->tr;
|
|
struct trace_array_cpu *data = tr->data[tr->cpu];
|
|
struct tracer *type = current_trace;
|
|
unsigned long entries;
|
|
unsigned long total;
|
|
const char *name = "preemption";
|
|
|
|
name = type->name;
|
|
|
|
get_total_entries(tr, &total, &entries);
|
|
|
|
seq_printf(m, "# %s latency trace v1.1.5 on %s\n",
|
|
name, UTS_RELEASE);
|
|
seq_puts(m, "# -----------------------------------"
|
|
"---------------------------------\n");
|
|
seq_printf(m, "# latency: %lu us, #%lu/%lu, CPU#%d |"
|
|
" (M:%s VP:%d, KP:%d, SP:%d HP:%d",
|
|
nsecs_to_usecs(data->saved_latency),
|
|
entries,
|
|
total,
|
|
tr->cpu,
|
|
#if defined(CONFIG_PREEMPT_NONE)
|
|
"server",
|
|
#elif defined(CONFIG_PREEMPT_VOLUNTARY)
|
|
"desktop",
|
|
#elif defined(CONFIG_PREEMPT)
|
|
"preempt",
|
|
#else
|
|
"unknown",
|
|
#endif
|
|
/* These are reserved for later use */
|
|
0, 0, 0, 0);
|
|
#ifdef CONFIG_SMP
|
|
seq_printf(m, " #P:%d)\n", num_online_cpus());
|
|
#else
|
|
seq_puts(m, ")\n");
|
|
#endif
|
|
seq_puts(m, "# -----------------\n");
|
|
seq_printf(m, "# | task: %.16s-%d "
|
|
"(uid:%d nice:%ld policy:%ld rt_prio:%ld)\n",
|
|
data->comm, data->pid,
|
|
from_kuid_munged(seq_user_ns(m), data->uid), data->nice,
|
|
data->policy, data->rt_priority);
|
|
seq_puts(m, "# -----------------\n");
|
|
|
|
if (data->critical_start) {
|
|
seq_puts(m, "# => started at: ");
|
|
seq_print_ip_sym(&iter->seq, data->critical_start, sym_flags);
|
|
trace_print_seq(m, &iter->seq);
|
|
seq_puts(m, "\n# => ended at: ");
|
|
seq_print_ip_sym(&iter->seq, data->critical_end, sym_flags);
|
|
trace_print_seq(m, &iter->seq);
|
|
seq_puts(m, "\n#\n");
|
|
}
|
|
|
|
seq_puts(m, "#\n");
|
|
}
|
|
|
|
static void test_cpu_buff_start(struct trace_iterator *iter)
|
|
{
|
|
struct trace_seq *s = &iter->seq;
|
|
|
|
if (!(trace_flags & TRACE_ITER_ANNOTATE))
|
|
return;
|
|
|
|
if (!(iter->iter_flags & TRACE_FILE_ANNOTATE))
|
|
return;
|
|
|
|
if (cpumask_test_cpu(iter->cpu, iter->started))
|
|
return;
|
|
|
|
if (iter->tr->data[iter->cpu]->skipped_entries)
|
|
return;
|
|
|
|
cpumask_set_cpu(iter->cpu, iter->started);
|
|
|
|
/* Don't print started cpu buffer for the first entry of the trace */
|
|
if (iter->idx > 1)
|
|
trace_seq_printf(s, "##### CPU %u buffer started ####\n",
|
|
iter->cpu);
|
|
}
|
|
|
|
static enum print_line_t print_trace_fmt(struct trace_iterator *iter)
|
|
{
|
|
struct trace_seq *s = &iter->seq;
|
|
unsigned long sym_flags = (trace_flags & TRACE_ITER_SYM_MASK);
|
|
struct trace_entry *entry;
|
|
struct trace_event *event;
|
|
|
|
entry = iter->ent;
|
|
|
|
test_cpu_buff_start(iter);
|
|
|
|
event = ftrace_find_event(entry->type);
|
|
|
|
if (trace_flags & TRACE_ITER_CONTEXT_INFO) {
|
|
if (iter->iter_flags & TRACE_FILE_LAT_FMT) {
|
|
if (!trace_print_lat_context(iter))
|
|
goto partial;
|
|
} else {
|
|
if (!trace_print_context(iter))
|
|
goto partial;
|
|
}
|
|
}
|
|
|
|
if (event)
|
|
return event->funcs->trace(iter, sym_flags, event);
|
|
|
|
if (!trace_seq_printf(s, "Unknown type %d\n", entry->type))
|
|
goto partial;
|
|
|
|
return TRACE_TYPE_HANDLED;
|
|
partial:
|
|
return TRACE_TYPE_PARTIAL_LINE;
|
|
}
|
|
|
|
static enum print_line_t print_raw_fmt(struct trace_iterator *iter)
|
|
{
|
|
struct trace_seq *s = &iter->seq;
|
|
struct trace_entry *entry;
|
|
struct trace_event *event;
|
|
|
|
entry = iter->ent;
|
|
|
|
if (trace_flags & TRACE_ITER_CONTEXT_INFO) {
|
|
if (!trace_seq_printf(s, "%d %d %llu ",
|
|
entry->pid, iter->cpu, iter->ts))
|
|
goto partial;
|
|
}
|
|
|
|
event = ftrace_find_event(entry->type);
|
|
if (event)
|
|
return event->funcs->raw(iter, 0, event);
|
|
|
|
if (!trace_seq_printf(s, "%d ?\n", entry->type))
|
|
goto partial;
|
|
|
|
return TRACE_TYPE_HANDLED;
|
|
partial:
|
|
return TRACE_TYPE_PARTIAL_LINE;
|
|
}
|
|
|
|
static enum print_line_t print_hex_fmt(struct trace_iterator *iter)
|
|
{
|
|
struct trace_seq *s = &iter->seq;
|
|
unsigned char newline = '\n';
|
|
struct trace_entry *entry;
|
|
struct trace_event *event;
|
|
|
|
entry = iter->ent;
|
|
|
|
if (trace_flags & TRACE_ITER_CONTEXT_INFO) {
|
|
SEQ_PUT_HEX_FIELD_RET(s, entry->pid);
|
|
SEQ_PUT_HEX_FIELD_RET(s, iter->cpu);
|
|
SEQ_PUT_HEX_FIELD_RET(s, iter->ts);
|
|
}
|
|
|
|
event = ftrace_find_event(entry->type);
|
|
if (event) {
|
|
enum print_line_t ret = event->funcs->hex(iter, 0, event);
|
|
if (ret != TRACE_TYPE_HANDLED)
|
|
return ret;
|
|
}
|
|
|
|
SEQ_PUT_FIELD_RET(s, newline);
|
|
|
|
return TRACE_TYPE_HANDLED;
|
|
}
|
|
|
|
static enum print_line_t print_bin_fmt(struct trace_iterator *iter)
|
|
{
|
|
struct trace_seq *s = &iter->seq;
|
|
struct trace_entry *entry;
|
|
struct trace_event *event;
|
|
|
|
entry = iter->ent;
|
|
|
|
if (trace_flags & TRACE_ITER_CONTEXT_INFO) {
|
|
SEQ_PUT_FIELD_RET(s, entry->pid);
|
|
SEQ_PUT_FIELD_RET(s, iter->cpu);
|
|
SEQ_PUT_FIELD_RET(s, iter->ts);
|
|
}
|
|
|
|
event = ftrace_find_event(entry->type);
|
|
return event ? event->funcs->binary(iter, 0, event) :
|
|
TRACE_TYPE_HANDLED;
|
|
}
|
|
|
|
int trace_empty(struct trace_iterator *iter)
|
|
{
|
|
struct ring_buffer_iter *buf_iter;
|
|
int cpu;
|
|
|
|
/* If we are looking at one CPU buffer, only check that one */
|
|
if (iter->cpu_file != TRACE_PIPE_ALL_CPU) {
|
|
cpu = iter->cpu_file;
|
|
buf_iter = trace_buffer_iter(iter, cpu);
|
|
if (buf_iter) {
|
|
if (!ring_buffer_iter_empty(buf_iter))
|
|
return 0;
|
|
} else {
|
|
if (!ring_buffer_empty_cpu(iter->tr->buffer, cpu))
|
|
return 0;
|
|
}
|
|
return 1;
|
|
}
|
|
|
|
for_each_tracing_cpu(cpu) {
|
|
buf_iter = trace_buffer_iter(iter, cpu);
|
|
if (buf_iter) {
|
|
if (!ring_buffer_iter_empty(buf_iter))
|
|
return 0;
|
|
} else {
|
|
if (!ring_buffer_empty_cpu(iter->tr->buffer, cpu))
|
|
return 0;
|
|
}
|
|
}
|
|
|
|
return 1;
|
|
}
|
|
|
|
/* Called with trace_event_read_lock() held. */
|
|
enum print_line_t print_trace_line(struct trace_iterator *iter)
|
|
{
|
|
enum print_line_t ret;
|
|
|
|
if (iter->lost_events &&
|
|
!trace_seq_printf(&iter->seq, "CPU:%d [LOST %lu EVENTS]\n",
|
|
iter->cpu, iter->lost_events))
|
|
return TRACE_TYPE_PARTIAL_LINE;
|
|
|
|
if (iter->trace && iter->trace->print_line) {
|
|
ret = iter->trace->print_line(iter);
|
|
if (ret != TRACE_TYPE_UNHANDLED)
|
|
return ret;
|
|
}
|
|
|
|
if (iter->ent->type == TRACE_BPRINT &&
|
|
trace_flags & TRACE_ITER_PRINTK &&
|
|
trace_flags & TRACE_ITER_PRINTK_MSGONLY)
|
|
return trace_print_bprintk_msg_only(iter);
|
|
|
|
if (iter->ent->type == TRACE_PRINT &&
|
|
trace_flags & TRACE_ITER_PRINTK &&
|
|
trace_flags & TRACE_ITER_PRINTK_MSGONLY)
|
|
return trace_print_printk_msg_only(iter);
|
|
|
|
if (trace_flags & TRACE_ITER_BIN)
|
|
return print_bin_fmt(iter);
|
|
|
|
if (trace_flags & TRACE_ITER_HEX)
|
|
return print_hex_fmt(iter);
|
|
|
|
if (trace_flags & TRACE_ITER_RAW)
|
|
return print_raw_fmt(iter);
|
|
|
|
return print_trace_fmt(iter);
|
|
}
|
|
|
|
void trace_latency_header(struct seq_file *m)
|
|
{
|
|
struct trace_iterator *iter = m->private;
|
|
|
|
/* print nothing if the buffers are empty */
|
|
if (trace_empty(iter))
|
|
return;
|
|
|
|
if (iter->iter_flags & TRACE_FILE_LAT_FMT)
|
|
print_trace_header(m, iter);
|
|
|
|
if (!(trace_flags & TRACE_ITER_VERBOSE))
|
|
print_lat_help_header(m);
|
|
}
|
|
|
|
void trace_default_header(struct seq_file *m)
|
|
{
|
|
struct trace_iterator *iter = m->private;
|
|
|
|
if (!(trace_flags & TRACE_ITER_CONTEXT_INFO))
|
|
return;
|
|
|
|
if (iter->iter_flags & TRACE_FILE_LAT_FMT) {
|
|
/* print nothing if the buffers are empty */
|
|
if (trace_empty(iter))
|
|
return;
|
|
print_trace_header(m, iter);
|
|
if (!(trace_flags & TRACE_ITER_VERBOSE))
|
|
print_lat_help_header(m);
|
|
} else {
|
|
if (!(trace_flags & TRACE_ITER_VERBOSE)) {
|
|
if (trace_flags & TRACE_ITER_IRQ_INFO)
|
|
print_func_help_header_irq(iter->tr, m);
|
|
else
|
|
print_func_help_header(iter->tr, m);
|
|
}
|
|
}
|
|
}
|
|
|
|
static void test_ftrace_alive(struct seq_file *m)
|
|
{
|
|
if (!ftrace_is_dead())
|
|
return;
|
|
seq_printf(m, "# WARNING: FUNCTION TRACING IS CORRUPTED\n");
|
|
seq_printf(m, "# MAY BE MISSING FUNCTION EVENTS\n");
|
|
}
|
|
|
|
#ifdef CONFIG_TRACER_MAX_TRACE
|
|
static void print_snapshot_help(struct seq_file *m, struct trace_iterator *iter)
|
|
{
|
|
if (iter->trace->allocated_snapshot)
|
|
seq_printf(m, "#\n# * Snapshot is allocated *\n#\n");
|
|
else
|
|
seq_printf(m, "#\n# * Snapshot is freed *\n#\n");
|
|
|
|
seq_printf(m, "# Snapshot commands:\n");
|
|
seq_printf(m, "# echo 0 > snapshot : Clears and frees snapshot buffer\n");
|
|
seq_printf(m, "# echo 1 > snapshot : Allocates snapshot buffer, if not already allocated.\n");
|
|
seq_printf(m, "# Takes a snapshot of the main buffer.\n");
|
|
seq_printf(m, "# echo 2 > snapshot : Clears snapshot buffer (but does not allocate)\n");
|
|
seq_printf(m, "# (Doesn't have to be '2' works with any number that\n");
|
|
seq_printf(m, "# is not a '0' or '1')\n");
|
|
}
|
|
#else
|
|
/* Should never be called */
|
|
static inline void print_snapshot_help(struct seq_file *m, struct trace_iterator *iter) { }
|
|
#endif
|
|
|
|
static int s_show(struct seq_file *m, void *v)
|
|
{
|
|
struct trace_iterator *iter = v;
|
|
int ret;
|
|
|
|
if (iter->ent == NULL) {
|
|
if (iter->tr) {
|
|
seq_printf(m, "# tracer: %s\n", iter->trace->name);
|
|
seq_puts(m, "#\n");
|
|
test_ftrace_alive(m);
|
|
}
|
|
if (iter->snapshot && trace_empty(iter))
|
|
print_snapshot_help(m, iter);
|
|
else if (iter->trace && iter->trace->print_header)
|
|
iter->trace->print_header(m);
|
|
else
|
|
trace_default_header(m);
|
|
|
|
} else if (iter->leftover) {
|
|
/*
|
|
* If we filled the seq_file buffer earlier, we
|
|
* want to just show it now.
|
|
*/
|
|
ret = trace_print_seq(m, &iter->seq);
|
|
|
|
/* ret should this time be zero, but you never know */
|
|
iter->leftover = ret;
|
|
|
|
} else {
|
|
print_trace_line(iter);
|
|
ret = trace_print_seq(m, &iter->seq);
|
|
/*
|
|
* If we overflow the seq_file buffer, then it will
|
|
* ask us for this data again at start up.
|
|
* Use that instead.
|
|
* ret is 0 if seq_file write succeeded.
|
|
* -1 otherwise.
|
|
*/
|
|
iter->leftover = ret;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static const struct seq_operations tracer_seq_ops = {
|
|
.start = s_start,
|
|
.next = s_next,
|
|
.stop = s_stop,
|
|
.show = s_show,
|
|
};
|
|
|
|
static struct trace_iterator *
|
|
__tracing_open(struct inode *inode, struct file *file, bool snapshot)
|
|
{
|
|
long cpu_file = (long) inode->i_private;
|
|
struct trace_iterator *iter;
|
|
int cpu;
|
|
|
|
if (tracing_disabled)
|
|
return ERR_PTR(-ENODEV);
|
|
|
|
iter = __seq_open_private(file, &tracer_seq_ops, sizeof(*iter));
|
|
if (!iter)
|
|
return ERR_PTR(-ENOMEM);
|
|
|
|
iter->buffer_iter = kzalloc(sizeof(*iter->buffer_iter) * num_possible_cpus(),
|
|
GFP_KERNEL);
|
|
if (!iter->buffer_iter)
|
|
goto release;
|
|
|
|
/*
|
|
* We make a copy of the current tracer to avoid concurrent
|
|
* changes on it while we are reading.
|
|
*/
|
|
mutex_lock(&trace_types_lock);
|
|
iter->trace = kzalloc(sizeof(*iter->trace), GFP_KERNEL);
|
|
if (!iter->trace)
|
|
goto fail;
|
|
|
|
*iter->trace = *current_trace;
|
|
|
|
if (!zalloc_cpumask_var(&iter->started, GFP_KERNEL))
|
|
goto fail;
|
|
|
|
if (current_trace->print_max || snapshot)
|
|
iter->tr = &max_tr;
|
|
else
|
|
iter->tr = &global_trace;
|
|
iter->snapshot = snapshot;
|
|
iter->pos = -1;
|
|
mutex_init(&iter->mutex);
|
|
iter->cpu_file = cpu_file;
|
|
|
|
/* Notify the tracer early; before we stop tracing. */
|
|
if (iter->trace && iter->trace->open)
|
|
iter->trace->open(iter);
|
|
|
|
/* Annotate start of buffers if we had overruns */
|
|
if (ring_buffer_overruns(iter->tr->buffer))
|
|
iter->iter_flags |= TRACE_FILE_ANNOTATE;
|
|
|
|
/* Output in nanoseconds only if we are using a clock in nanoseconds. */
|
|
if (trace_clocks[trace_clock_id].in_ns)
|
|
iter->iter_flags |= TRACE_FILE_TIME_IN_NS;
|
|
|
|
/* stop the trace while dumping if we are not opening "snapshot" */
|
|
if (!iter->snapshot)
|
|
tracing_stop();
|
|
|
|
if (iter->cpu_file == TRACE_PIPE_ALL_CPU) {
|
|
for_each_tracing_cpu(cpu) {
|
|
iter->buffer_iter[cpu] =
|
|
ring_buffer_read_prepare(iter->tr->buffer, cpu);
|
|
}
|
|
ring_buffer_read_prepare_sync();
|
|
for_each_tracing_cpu(cpu) {
|
|
ring_buffer_read_start(iter->buffer_iter[cpu]);
|
|
tracing_iter_reset(iter, cpu);
|
|
}
|
|
} else {
|
|
cpu = iter->cpu_file;
|
|
iter->buffer_iter[cpu] =
|
|
ring_buffer_read_prepare(iter->tr->buffer, cpu);
|
|
ring_buffer_read_prepare_sync();
|
|
ring_buffer_read_start(iter->buffer_iter[cpu]);
|
|
tracing_iter_reset(iter, cpu);
|
|
}
|
|
|
|
mutex_unlock(&trace_types_lock);
|
|
|
|
return iter;
|
|
|
|
fail:
|
|
mutex_unlock(&trace_types_lock);
|
|
kfree(iter->trace);
|
|
kfree(iter->buffer_iter);
|
|
release:
|
|
seq_release_private(inode, file);
|
|
return ERR_PTR(-ENOMEM);
|
|
}
|
|
|
|
int tracing_open_generic(struct inode *inode, struct file *filp)
|
|
{
|
|
if (tracing_disabled)
|
|
return -ENODEV;
|
|
|
|
filp->private_data = inode->i_private;
|
|
return 0;
|
|
}
|
|
|
|
static int tracing_release(struct inode *inode, struct file *file)
|
|
{
|
|
struct seq_file *m = file->private_data;
|
|
struct trace_iterator *iter;
|
|
int cpu;
|
|
|
|
if (!(file->f_mode & FMODE_READ))
|
|
return 0;
|
|
|
|
iter = m->private;
|
|
|
|
mutex_lock(&trace_types_lock);
|
|
for_each_tracing_cpu(cpu) {
|
|
if (iter->buffer_iter[cpu])
|
|
ring_buffer_read_finish(iter->buffer_iter[cpu]);
|
|
}
|
|
|
|
if (iter->trace && iter->trace->close)
|
|
iter->trace->close(iter);
|
|
|
|
if (!iter->snapshot)
|
|
/* reenable tracing if it was previously enabled */
|
|
tracing_start();
|
|
mutex_unlock(&trace_types_lock);
|
|
|
|
mutex_destroy(&iter->mutex);
|
|
free_cpumask_var(iter->started);
|
|
kfree(iter->trace);
|
|
kfree(iter->buffer_iter);
|
|
seq_release_private(inode, file);
|
|
return 0;
|
|
}
|
|
|
|
static int tracing_open(struct inode *inode, struct file *file)
|
|
{
|
|
struct trace_iterator *iter;
|
|
int ret = 0;
|
|
|
|
/* If this file was open for write, then erase contents */
|
|
if ((file->f_mode & FMODE_WRITE) &&
|
|
(file->f_flags & O_TRUNC)) {
|
|
long cpu = (long) inode->i_private;
|
|
|
|
if (cpu == TRACE_PIPE_ALL_CPU)
|
|
tracing_reset_online_cpus(&global_trace);
|
|
else
|
|
tracing_reset(&global_trace, cpu);
|
|
}
|
|
|
|
if (file->f_mode & FMODE_READ) {
|
|
iter = __tracing_open(inode, file, false);
|
|
if (IS_ERR(iter))
|
|
ret = PTR_ERR(iter);
|
|
else if (trace_flags & TRACE_ITER_LATENCY_FMT)
|
|
iter->iter_flags |= TRACE_FILE_LAT_FMT;
|
|
}
|
|
return ret;
|
|
}
|
|
|
|
static void *
|
|
t_next(struct seq_file *m, void *v, loff_t *pos)
|
|
{
|
|
struct tracer *t = v;
|
|
|
|
(*pos)++;
|
|
|
|
if (t)
|
|
t = t->next;
|
|
|
|
return t;
|
|
}
|
|
|
|
static void *t_start(struct seq_file *m, loff_t *pos)
|
|
{
|
|
struct tracer *t;
|
|
loff_t l = 0;
|
|
|
|
mutex_lock(&trace_types_lock);
|
|
for (t = trace_types; t && l < *pos; t = t_next(m, t, &l))
|
|
;
|
|
|
|
return t;
|
|
}
|
|
|
|
static void t_stop(struct seq_file *m, void *p)
|
|
{
|
|
mutex_unlock(&trace_types_lock);
|
|
}
|
|
|
|
static int t_show(struct seq_file *m, void *v)
|
|
{
|
|
struct tracer *t = v;
|
|
|
|
if (!t)
|
|
return 0;
|
|
|
|
seq_printf(m, "%s", t->name);
|
|
if (t->next)
|
|
seq_putc(m, ' ');
|
|
else
|
|
seq_putc(m, '\n');
|
|
|
|
return 0;
|
|
}
|
|
|
|
static const struct seq_operations show_traces_seq_ops = {
|
|
.start = t_start,
|
|
.next = t_next,
|
|
.stop = t_stop,
|
|
.show = t_show,
|
|
};
|
|
|
|
static int show_traces_open(struct inode *inode, struct file *file)
|
|
{
|
|
if (tracing_disabled)
|
|
return -ENODEV;
|
|
|
|
return seq_open(file, &show_traces_seq_ops);
|
|
}
|
|
|
|
static ssize_t
|
|
tracing_write_stub(struct file *filp, const char __user *ubuf,
|
|
size_t count, loff_t *ppos)
|
|
{
|
|
return count;
|
|
}
|
|
|
|
static loff_t tracing_seek(struct file *file, loff_t offset, int origin)
|
|
{
|
|
if (file->f_mode & FMODE_READ)
|
|
return seq_lseek(file, offset, origin);
|
|
else
|
|
return 0;
|
|
}
|
|
|
|
static const struct file_operations tracing_fops = {
|
|
.open = tracing_open,
|
|
.read = seq_read,
|
|
.write = tracing_write_stub,
|
|
.llseek = tracing_seek,
|
|
.release = tracing_release,
|
|
};
|
|
|
|
static const struct file_operations show_traces_fops = {
|
|
.open = show_traces_open,
|
|
.read = seq_read,
|
|
.release = seq_release,
|
|
.llseek = seq_lseek,
|
|
};
|
|
|
|
/*
|
|
* Only trace on a CPU if the bitmask is set:
|
|
*/
|
|
static cpumask_var_t tracing_cpumask;
|
|
|
|
/*
|
|
* The tracer itself will not take this lock, but still we want
|
|
* to provide a consistent cpumask to user-space:
|
|
*/
|
|
static DEFINE_MUTEX(tracing_cpumask_update_lock);
|
|
|
|
/*
|
|
* Temporary storage for the character representation of the
|
|
* CPU bitmask (and one more byte for the newline):
|
|
*/
|
|
static char mask_str[NR_CPUS + 1];
|
|
|
|
static ssize_t
|
|
tracing_cpumask_read(struct file *filp, char __user *ubuf,
|
|
size_t count, loff_t *ppos)
|
|
{
|
|
int len;
|
|
|
|
mutex_lock(&tracing_cpumask_update_lock);
|
|
|
|
len = cpumask_scnprintf(mask_str, count, tracing_cpumask);
|
|
if (count - len < 2) {
|
|
count = -EINVAL;
|
|
goto out_err;
|
|
}
|
|
len += sprintf(mask_str + len, "\n");
|
|
count = simple_read_from_buffer(ubuf, count, ppos, mask_str, NR_CPUS+1);
|
|
|
|
out_err:
|
|
mutex_unlock(&tracing_cpumask_update_lock);
|
|
|
|
return count;
|
|
}
|
|
|
|
static ssize_t
|
|
tracing_cpumask_write(struct file *filp, const char __user *ubuf,
|
|
size_t count, loff_t *ppos)
|
|
{
|
|
int err, cpu;
|
|
cpumask_var_t tracing_cpumask_new;
|
|
|
|
if (!alloc_cpumask_var(&tracing_cpumask_new, GFP_KERNEL))
|
|
return -ENOMEM;
|
|
|
|
err = cpumask_parse_user(ubuf, count, tracing_cpumask_new);
|
|
if (err)
|
|
goto err_unlock;
|
|
|
|
mutex_lock(&tracing_cpumask_update_lock);
|
|
|
|
local_irq_disable();
|
|
arch_spin_lock(&ftrace_max_lock);
|
|
for_each_tracing_cpu(cpu) {
|
|
/*
|
|
* Increase/decrease the disabled counter if we are
|
|
* about to flip a bit in the cpumask:
|
|
*/
|
|
if (cpumask_test_cpu(cpu, tracing_cpumask) &&
|
|
!cpumask_test_cpu(cpu, tracing_cpumask_new)) {
|
|
atomic_inc(&global_trace.data[cpu]->disabled);
|
|
ring_buffer_record_disable_cpu(global_trace.buffer, cpu);
|
|
}
|
|
if (!cpumask_test_cpu(cpu, tracing_cpumask) &&
|
|
cpumask_test_cpu(cpu, tracing_cpumask_new)) {
|
|
atomic_dec(&global_trace.data[cpu]->disabled);
|
|
ring_buffer_record_enable_cpu(global_trace.buffer, cpu);
|
|
}
|
|
}
|
|
arch_spin_unlock(&ftrace_max_lock);
|
|
local_irq_enable();
|
|
|
|
cpumask_copy(tracing_cpumask, tracing_cpumask_new);
|
|
|
|
mutex_unlock(&tracing_cpumask_update_lock);
|
|
free_cpumask_var(tracing_cpumask_new);
|
|
|
|
return count;
|
|
|
|
err_unlock:
|
|
free_cpumask_var(tracing_cpumask_new);
|
|
|
|
return err;
|
|
}
|
|
|
|
static const struct file_operations tracing_cpumask_fops = {
|
|
.open = tracing_open_generic,
|
|
.read = tracing_cpumask_read,
|
|
.write = tracing_cpumask_write,
|
|
.llseek = generic_file_llseek,
|
|
};
|
|
|
|
static int tracing_trace_options_show(struct seq_file *m, void *v)
|
|
{
|
|
struct tracer_opt *trace_opts;
|
|
u32 tracer_flags;
|
|
int i;
|
|
|
|
mutex_lock(&trace_types_lock);
|
|
tracer_flags = current_trace->flags->val;
|
|
trace_opts = current_trace->flags->opts;
|
|
|
|
for (i = 0; trace_options[i]; i++) {
|
|
if (trace_flags & (1 << i))
|
|
seq_printf(m, "%s\n", trace_options[i]);
|
|
else
|
|
seq_printf(m, "no%s\n", trace_options[i]);
|
|
}
|
|
|
|
for (i = 0; trace_opts[i].name; i++) {
|
|
if (tracer_flags & trace_opts[i].bit)
|
|
seq_printf(m, "%s\n", trace_opts[i].name);
|
|
else
|
|
seq_printf(m, "no%s\n", trace_opts[i].name);
|
|
}
|
|
mutex_unlock(&trace_types_lock);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int __set_tracer_option(struct tracer *trace,
|
|
struct tracer_flags *tracer_flags,
|
|
struct tracer_opt *opts, int neg)
|
|
{
|
|
int ret;
|
|
|
|
ret = trace->set_flag(tracer_flags->val, opts->bit, !neg);
|
|
if (ret)
|
|
return ret;
|
|
|
|
if (neg)
|
|
tracer_flags->val &= ~opts->bit;
|
|
else
|
|
tracer_flags->val |= opts->bit;
|
|
return 0;
|
|
}
|
|
|
|
/* Try to assign a tracer specific option */
|
|
static int set_tracer_option(struct tracer *trace, char *cmp, int neg)
|
|
{
|
|
struct tracer_flags *tracer_flags = trace->flags;
|
|
struct tracer_opt *opts = NULL;
|
|
int i;
|
|
|
|
for (i = 0; tracer_flags->opts[i].name; i++) {
|
|
opts = &tracer_flags->opts[i];
|
|
|
|
if (strcmp(cmp, opts->name) == 0)
|
|
return __set_tracer_option(trace, trace->flags,
|
|
opts, neg);
|
|
}
|
|
|
|
return -EINVAL;
|
|
}
|
|
|
|
/* Some tracers require overwrite to stay enabled */
|
|
int trace_keep_overwrite(struct tracer *tracer, u32 mask, int set)
|
|
{
|
|
if (tracer->enabled && (mask & TRACE_ITER_OVERWRITE) && !set)
|
|
return -1;
|
|
|
|
return 0;
|
|
}
|
|
|
|
int set_tracer_flag(unsigned int mask, int enabled)
|
|
{
|
|
/* do nothing if flag is already set */
|
|
if (!!(trace_flags & mask) == !!enabled)
|
|
return 0;
|
|
|
|
/* Give the tracer a chance to approve the change */
|
|
if (current_trace->flag_changed)
|
|
if (current_trace->flag_changed(current_trace, mask, !!enabled))
|
|
return -EINVAL;
|
|
|
|
if (enabled)
|
|
trace_flags |= mask;
|
|
else
|
|
trace_flags &= ~mask;
|
|
|
|
if (mask == TRACE_ITER_RECORD_CMD)
|
|
trace_event_enable_cmd_record(enabled);
|
|
|
|
if (mask == TRACE_ITER_OVERWRITE) {
|
|
ring_buffer_change_overwrite(global_trace.buffer, enabled);
|
|
#ifdef CONFIG_TRACER_MAX_TRACE
|
|
ring_buffer_change_overwrite(max_tr.buffer, enabled);
|
|
#endif
|
|
}
|
|
|
|
if (mask == TRACE_ITER_PRINTK)
|
|
trace_printk_start_stop_comm(enabled);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int trace_set_options(char *option)
|
|
{
|
|
char *cmp;
|
|
int neg = 0;
|
|
int ret = -ENODEV;
|
|
int i;
|
|
|
|
cmp = strstrip(option);
|
|
|
|
if (strncmp(cmp, "no", 2) == 0) {
|
|
neg = 1;
|
|
cmp += 2;
|
|
}
|
|
|
|
mutex_lock(&trace_types_lock);
|
|
|
|
for (i = 0; trace_options[i]; i++) {
|
|
if (strcmp(cmp, trace_options[i]) == 0) {
|
|
ret = set_tracer_flag(1 << i, !neg);
|
|
break;
|
|
}
|
|
}
|
|
|
|
/* If no option could be set, test the specific tracer options */
|
|
if (!trace_options[i])
|
|
ret = set_tracer_option(current_trace, cmp, neg);
|
|
|
|
mutex_unlock(&trace_types_lock);
|
|
|
|
return ret;
|
|
}
|
|
|
|
static ssize_t
|
|
tracing_trace_options_write(struct file *filp, const char __user *ubuf,
|
|
size_t cnt, loff_t *ppos)
|
|
{
|
|
char buf[64];
|
|
int ret;
|
|
|
|
if (cnt >= sizeof(buf))
|
|
return -EINVAL;
|
|
|
|
if (copy_from_user(&buf, ubuf, cnt))
|
|
return -EFAULT;
|
|
|
|
buf[cnt] = 0;
|
|
|
|
ret = trace_set_options(buf);
|
|
if (ret < 0)
|
|
return ret;
|
|
|
|
*ppos += cnt;
|
|
|
|
return cnt;
|
|
}
|
|
|
|
static int tracing_trace_options_open(struct inode *inode, struct file *file)
|
|
{
|
|
if (tracing_disabled)
|
|
return -ENODEV;
|
|
return single_open(file, tracing_trace_options_show, NULL);
|
|
}
|
|
|
|
static const struct file_operations tracing_iter_fops = {
|
|
.open = tracing_trace_options_open,
|
|
.read = seq_read,
|
|
.llseek = seq_lseek,
|
|
.release = single_release,
|
|
.write = tracing_trace_options_write,
|
|
};
|
|
|
|
static const char readme_msg[] =
|
|
"tracing mini-HOWTO:\n\n"
|
|
"# mount -t debugfs nodev /sys/kernel/debug\n\n"
|
|
"# cat /sys/kernel/debug/tracing/available_tracers\n"
|
|
"wakeup wakeup_rt preemptirqsoff preemptoff irqsoff function nop\n\n"
|
|
"# cat /sys/kernel/debug/tracing/current_tracer\n"
|
|
"nop\n"
|
|
"# echo wakeup > /sys/kernel/debug/tracing/current_tracer\n"
|
|
"# cat /sys/kernel/debug/tracing/current_tracer\n"
|
|
"wakeup\n"
|
|
"# cat /sys/kernel/debug/tracing/trace_options\n"
|
|
"noprint-parent nosym-offset nosym-addr noverbose\n"
|
|
"# echo print-parent > /sys/kernel/debug/tracing/trace_options\n"
|
|
"# echo 1 > /sys/kernel/debug/tracing/tracing_on\n"
|
|
"# cat /sys/kernel/debug/tracing/trace > /tmp/trace.txt\n"
|
|
"# echo 0 > /sys/kernel/debug/tracing/tracing_on\n"
|
|
;
|
|
|
|
static ssize_t
|
|
tracing_readme_read(struct file *filp, char __user *ubuf,
|
|
size_t cnt, loff_t *ppos)
|
|
{
|
|
return simple_read_from_buffer(ubuf, cnt, ppos,
|
|
readme_msg, strlen(readme_msg));
|
|
}
|
|
|
|
static const struct file_operations tracing_readme_fops = {
|
|
.open = tracing_open_generic,
|
|
.read = tracing_readme_read,
|
|
.llseek = generic_file_llseek,
|
|
};
|
|
|
|
static ssize_t
|
|
tracing_saved_cmdlines_read(struct file *file, char __user *ubuf,
|
|
size_t cnt, loff_t *ppos)
|
|
{
|
|
char *buf_comm;
|
|
char *file_buf;
|
|
char *buf;
|
|
int len = 0;
|
|
int pid;
|
|
int i;
|
|
|
|
file_buf = kmalloc(SAVED_CMDLINES*(16+TASK_COMM_LEN), GFP_KERNEL);
|
|
if (!file_buf)
|
|
return -ENOMEM;
|
|
|
|
buf_comm = kmalloc(TASK_COMM_LEN, GFP_KERNEL);
|
|
if (!buf_comm) {
|
|
kfree(file_buf);
|
|
return -ENOMEM;
|
|
}
|
|
|
|
buf = file_buf;
|
|
|
|
for (i = 0; i < SAVED_CMDLINES; i++) {
|
|
int r;
|
|
|
|
pid = map_cmdline_to_pid[i];
|
|
if (pid == -1 || pid == NO_CMDLINE_MAP)
|
|
continue;
|
|
|
|
trace_find_cmdline(pid, buf_comm);
|
|
r = sprintf(buf, "%d %s\n", pid, buf_comm);
|
|
buf += r;
|
|
len += r;
|
|
}
|
|
|
|
len = simple_read_from_buffer(ubuf, cnt, ppos,
|
|
file_buf, len);
|
|
|
|
kfree(file_buf);
|
|
kfree(buf_comm);
|
|
|
|
return len;
|
|
}
|
|
|
|
static const struct file_operations tracing_saved_cmdlines_fops = {
|
|
.open = tracing_open_generic,
|
|
.read = tracing_saved_cmdlines_read,
|
|
.llseek = generic_file_llseek,
|
|
};
|
|
|
|
static ssize_t
|
|
tracing_set_trace_read(struct file *filp, char __user *ubuf,
|
|
size_t cnt, loff_t *ppos)
|
|
{
|
|
char buf[MAX_TRACER_SIZE+2];
|
|
int r;
|
|
|
|
mutex_lock(&trace_types_lock);
|
|
r = sprintf(buf, "%s\n", current_trace->name);
|
|
mutex_unlock(&trace_types_lock);
|
|
|
|
return simple_read_from_buffer(ubuf, cnt, ppos, buf, r);
|
|
}
|
|
|
|
int tracer_init(struct tracer *t, struct trace_array *tr)
|
|
{
|
|
tracing_reset_online_cpus(tr);
|
|
return t->init(tr);
|
|
}
|
|
|
|
static void set_buffer_entries(struct trace_array *tr, unsigned long val)
|
|
{
|
|
int cpu;
|
|
for_each_tracing_cpu(cpu)
|
|
tr->data[cpu]->entries = val;
|
|
}
|
|
|
|
/* resize @tr's buffer to the size of @size_tr's entries */
|
|
static int resize_buffer_duplicate_size(struct trace_array *tr,
|
|
struct trace_array *size_tr, int cpu_id)
|
|
{
|
|
int cpu, ret = 0;
|
|
|
|
if (cpu_id == RING_BUFFER_ALL_CPUS) {
|
|
for_each_tracing_cpu(cpu) {
|
|
ret = ring_buffer_resize(tr->buffer,
|
|
size_tr->data[cpu]->entries, cpu);
|
|
if (ret < 0)
|
|
break;
|
|
tr->data[cpu]->entries = size_tr->data[cpu]->entries;
|
|
}
|
|
} else {
|
|
ret = ring_buffer_resize(tr->buffer,
|
|
size_tr->data[cpu_id]->entries, cpu_id);
|
|
if (ret == 0)
|
|
tr->data[cpu_id]->entries =
|
|
size_tr->data[cpu_id]->entries;
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
|
|
static int __tracing_resize_ring_buffer(unsigned long size, int cpu)
|
|
{
|
|
int ret;
|
|
|
|
/*
|
|
* If kernel or user changes the size of the ring buffer
|
|
* we use the size that was given, and we can forget about
|
|
* expanding it later.
|
|
*/
|
|
ring_buffer_expanded = 1;
|
|
|
|
/* May be called before buffers are initialized */
|
|
if (!global_trace.buffer)
|
|
return 0;
|
|
|
|
ret = ring_buffer_resize(global_trace.buffer, size, cpu);
|
|
if (ret < 0)
|
|
return ret;
|
|
|
|
if (!current_trace->use_max_tr)
|
|
goto out;
|
|
|
|
ret = ring_buffer_resize(max_tr.buffer, size, cpu);
|
|
if (ret < 0) {
|
|
int r = resize_buffer_duplicate_size(&global_trace,
|
|
&global_trace, cpu);
|
|
if (r < 0) {
|
|
/*
|
|
* AARGH! We are left with different
|
|
* size max buffer!!!!
|
|
* The max buffer is our "snapshot" buffer.
|
|
* When a tracer needs a snapshot (one of the
|
|
* latency tracers), it swaps the max buffer
|
|
* with the saved snap shot. We succeeded to
|
|
* update the size of the main buffer, but failed to
|
|
* update the size of the max buffer. But when we tried
|
|
* to reset the main buffer to the original size, we
|
|
* failed there too. This is very unlikely to
|
|
* happen, but if it does, warn and kill all
|
|
* tracing.
|
|
*/
|
|
WARN_ON(1);
|
|
tracing_disabled = 1;
|
|
}
|
|
return ret;
|
|
}
|
|
|
|
if (cpu == RING_BUFFER_ALL_CPUS)
|
|
set_buffer_entries(&max_tr, size);
|
|
else
|
|
max_tr.data[cpu]->entries = size;
|
|
|
|
out:
|
|
if (cpu == RING_BUFFER_ALL_CPUS)
|
|
set_buffer_entries(&global_trace, size);
|
|
else
|
|
global_trace.data[cpu]->entries = size;
|
|
|
|
return ret;
|
|
}
|
|
|
|
static ssize_t tracing_resize_ring_buffer(unsigned long size, int cpu_id)
|
|
{
|
|
int ret = size;
|
|
|
|
mutex_lock(&trace_types_lock);
|
|
|
|
if (cpu_id != RING_BUFFER_ALL_CPUS) {
|
|
/* make sure, this cpu is enabled in the mask */
|
|
if (!cpumask_test_cpu(cpu_id, tracing_buffer_mask)) {
|
|
ret = -EINVAL;
|
|
goto out;
|
|
}
|
|
}
|
|
|
|
ret = __tracing_resize_ring_buffer(size, cpu_id);
|
|
if (ret < 0)
|
|
ret = -ENOMEM;
|
|
|
|
out:
|
|
mutex_unlock(&trace_types_lock);
|
|
|
|
return ret;
|
|
}
|
|
|
|
|
|
/**
|
|
* tracing_update_buffers - used by tracing facility to expand ring buffers
|
|
*
|
|
* To save on memory when the tracing is never used on a system with it
|
|
* configured in. The ring buffers are set to a minimum size. But once
|
|
* a user starts to use the tracing facility, then they need to grow
|
|
* to their default size.
|
|
*
|
|
* This function is to be called when a tracer is about to be used.
|
|
*/
|
|
int tracing_update_buffers(void)
|
|
{
|
|
int ret = 0;
|
|
|
|
mutex_lock(&trace_types_lock);
|
|
if (!ring_buffer_expanded)
|
|
ret = __tracing_resize_ring_buffer(trace_buf_size,
|
|
RING_BUFFER_ALL_CPUS);
|
|
mutex_unlock(&trace_types_lock);
|
|
|
|
return ret;
|
|
}
|
|
|
|
struct trace_option_dentry;
|
|
|
|
static struct trace_option_dentry *
|
|
create_trace_option_files(struct tracer *tracer);
|
|
|
|
static void
|
|
destroy_trace_option_files(struct trace_option_dentry *topts);
|
|
|
|
static int tracing_set_tracer(const char *buf)
|
|
{
|
|
static struct trace_option_dentry *topts;
|
|
struct trace_array *tr = &global_trace;
|
|
struct tracer *t;
|
|
bool had_max_tr;
|
|
int ret = 0;
|
|
|
|
mutex_lock(&trace_types_lock);
|
|
|
|
if (!ring_buffer_expanded) {
|
|
ret = __tracing_resize_ring_buffer(trace_buf_size,
|
|
RING_BUFFER_ALL_CPUS);
|
|
if (ret < 0)
|
|
goto out;
|
|
ret = 0;
|
|
}
|
|
|
|
for (t = trace_types; t; t = t->next) {
|
|
if (strcmp(t->name, buf) == 0)
|
|
break;
|
|
}
|
|
if (!t) {
|
|
ret = -EINVAL;
|
|
goto out;
|
|
}
|
|
if (t == current_trace)
|
|
goto out;
|
|
|
|
trace_branch_disable();
|
|
|
|
current_trace->enabled = false;
|
|
|
|
if (current_trace->reset)
|
|
current_trace->reset(tr);
|
|
|
|
had_max_tr = current_trace->allocated_snapshot;
|
|
current_trace = &nop_trace;
|
|
|
|
if (had_max_tr && !t->use_max_tr) {
|
|
/*
|
|
* We need to make sure that the update_max_tr sees that
|
|
* current_trace changed to nop_trace to keep it from
|
|
* swapping the buffers after we resize it.
|
|
* The update_max_tr is called from interrupts disabled
|
|
* so a synchronized_sched() is sufficient.
|
|
*/
|
|
synchronize_sched();
|
|
/*
|
|
* We don't free the ring buffer. instead, resize it because
|
|
* The max_tr ring buffer has some state (e.g. ring->clock) and
|
|
* we want preserve it.
|
|
*/
|
|
ring_buffer_resize(max_tr.buffer, 1, RING_BUFFER_ALL_CPUS);
|
|
set_buffer_entries(&max_tr, 1);
|
|
tracing_reset_online_cpus(&max_tr);
|
|
current_trace->allocated_snapshot = false;
|
|
}
|
|
destroy_trace_option_files(topts);
|
|
|
|
topts = create_trace_option_files(t);
|
|
if (t->use_max_tr && !had_max_tr) {
|
|
/* we need to make per cpu buffer sizes equivalent */
|
|
ret = resize_buffer_duplicate_size(&max_tr, &global_trace,
|
|
RING_BUFFER_ALL_CPUS);
|
|
if (ret < 0)
|
|
goto out;
|
|
t->allocated_snapshot = true;
|
|
}
|
|
|
|
if (t->init) {
|
|
ret = tracer_init(t, tr);
|
|
if (ret)
|
|
goto out;
|
|
}
|
|
|
|
current_trace = t;
|
|
current_trace->enabled = true;
|
|
trace_branch_enable(tr);
|
|
out:
|
|
mutex_unlock(&trace_types_lock);
|
|
|
|
return ret;
|
|
}
|
|
|
|
static ssize_t
|
|
tracing_set_trace_write(struct file *filp, const char __user *ubuf,
|
|
size_t cnt, loff_t *ppos)
|
|
{
|
|
char buf[MAX_TRACER_SIZE+1];
|
|
int i;
|
|
size_t ret;
|
|
int err;
|
|
|
|
ret = cnt;
|
|
|
|
if (cnt > MAX_TRACER_SIZE)
|
|
cnt = MAX_TRACER_SIZE;
|
|
|
|
if (copy_from_user(&buf, ubuf, cnt))
|
|
return -EFAULT;
|
|
|
|
buf[cnt] = 0;
|
|
|
|
/* strip ending whitespace. */
|
|
for (i = cnt - 1; i > 0 && isspace(buf[i]); i--)
|
|
buf[i] = 0;
|
|
|
|
err = tracing_set_tracer(buf);
|
|
if (err)
|
|
return err;
|
|
|
|
*ppos += ret;
|
|
|
|
return ret;
|
|
}
|
|
|
|
static ssize_t
|
|
tracing_max_lat_read(struct file *filp, char __user *ubuf,
|
|
size_t cnt, loff_t *ppos)
|
|
{
|
|
unsigned long *ptr = filp->private_data;
|
|
char buf[64];
|
|
int r;
|
|
|
|
r = snprintf(buf, sizeof(buf), "%ld\n",
|
|
*ptr == (unsigned long)-1 ? -1 : nsecs_to_usecs(*ptr));
|
|
if (r > sizeof(buf))
|
|
r = sizeof(buf);
|
|
return simple_read_from_buffer(ubuf, cnt, ppos, buf, r);
|
|
}
|
|
|
|
static ssize_t
|
|
tracing_max_lat_write(struct file *filp, const char __user *ubuf,
|
|
size_t cnt, loff_t *ppos)
|
|
{
|
|
unsigned long *ptr = filp->private_data;
|
|
unsigned long val;
|
|
int ret;
|
|
|
|
ret = kstrtoul_from_user(ubuf, cnt, 10, &val);
|
|
if (ret)
|
|
return ret;
|
|
|
|
*ptr = val * 1000;
|
|
|
|
return cnt;
|
|
}
|
|
|
|
static int tracing_open_pipe(struct inode *inode, struct file *filp)
|
|
{
|
|
long cpu_file = (long) inode->i_private;
|
|
struct trace_iterator *iter;
|
|
int ret = 0;
|
|
|
|
if (tracing_disabled)
|
|
return -ENODEV;
|
|
|
|
mutex_lock(&trace_types_lock);
|
|
|
|
/* create a buffer to store the information to pass to userspace */
|
|
iter = kzalloc(sizeof(*iter), GFP_KERNEL);
|
|
if (!iter) {
|
|
ret = -ENOMEM;
|
|
goto out;
|
|
}
|
|
|
|
/*
|
|
* We make a copy of the current tracer to avoid concurrent
|
|
* changes on it while we are reading.
|
|
*/
|
|
iter->trace = kmalloc(sizeof(*iter->trace), GFP_KERNEL);
|
|
if (!iter->trace) {
|
|
ret = -ENOMEM;
|
|
goto fail;
|
|
}
|
|
*iter->trace = *current_trace;
|
|
|
|
if (!alloc_cpumask_var(&iter->started, GFP_KERNEL)) {
|
|
ret = -ENOMEM;
|
|
goto fail;
|
|
}
|
|
|
|
/* trace pipe does not show start of buffer */
|
|
cpumask_setall(iter->started);
|
|
|
|
if (trace_flags & TRACE_ITER_LATENCY_FMT)
|
|
iter->iter_flags |= TRACE_FILE_LAT_FMT;
|
|
|
|
/* Output in nanoseconds only if we are using a clock in nanoseconds. */
|
|
if (trace_clocks[trace_clock_id].in_ns)
|
|
iter->iter_flags |= TRACE_FILE_TIME_IN_NS;
|
|
|
|
iter->cpu_file = cpu_file;
|
|
iter->tr = &global_trace;
|
|
mutex_init(&iter->mutex);
|
|
filp->private_data = iter;
|
|
|
|
if (iter->trace->pipe_open)
|
|
iter->trace->pipe_open(iter);
|
|
|
|
nonseekable_open(inode, filp);
|
|
out:
|
|
mutex_unlock(&trace_types_lock);
|
|
return ret;
|
|
|
|
fail:
|
|
kfree(iter->trace);
|
|
kfree(iter);
|
|
mutex_unlock(&trace_types_lock);
|
|
return ret;
|
|
}
|
|
|
|
static int tracing_release_pipe(struct inode *inode, struct file *file)
|
|
{
|
|
struct trace_iterator *iter = file->private_data;
|
|
|
|
mutex_lock(&trace_types_lock);
|
|
|
|
if (iter->trace->pipe_close)
|
|
iter->trace->pipe_close(iter);
|
|
|
|
mutex_unlock(&trace_types_lock);
|
|
|
|
free_cpumask_var(iter->started);
|
|
mutex_destroy(&iter->mutex);
|
|
kfree(iter->trace);
|
|
kfree(iter);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static unsigned int
|
|
tracing_poll_pipe(struct file *filp, poll_table *poll_table)
|
|
{
|
|
struct trace_iterator *iter = filp->private_data;
|
|
|
|
if (trace_flags & TRACE_ITER_BLOCK) {
|
|
/*
|
|
* Always select as readable when in blocking mode
|
|
*/
|
|
return POLLIN | POLLRDNORM;
|
|
} else {
|
|
if (!trace_empty(iter))
|
|
return POLLIN | POLLRDNORM;
|
|
poll_wait(filp, &trace_wait, poll_table);
|
|
if (!trace_empty(iter))
|
|
return POLLIN | POLLRDNORM;
|
|
|
|
return 0;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* This is a make-shift waitqueue.
|
|
* A tracer might use this callback on some rare cases:
|
|
*
|
|
* 1) the current tracer might hold the runqueue lock when it wakes up
|
|
* a reader, hence a deadlock (sched, function, and function graph tracers)
|
|
* 2) the function tracers, trace all functions, we don't want
|
|
* the overhead of calling wake_up and friends
|
|
* (and tracing them too)
|
|
*
|
|
* Anyway, this is really very primitive wakeup.
|
|
*/
|
|
void poll_wait_pipe(struct trace_iterator *iter)
|
|
{
|
|
set_current_state(TASK_INTERRUPTIBLE);
|
|
/* sleep for 100 msecs, and try again. */
|
|
schedule_timeout(HZ / 10);
|
|
}
|
|
|
|
/* Must be called with trace_types_lock mutex held. */
|
|
static int tracing_wait_pipe(struct file *filp)
|
|
{
|
|
struct trace_iterator *iter = filp->private_data;
|
|
|
|
while (trace_empty(iter)) {
|
|
|
|
if ((filp->f_flags & O_NONBLOCK)) {
|
|
return -EAGAIN;
|
|
}
|
|
|
|
mutex_unlock(&iter->mutex);
|
|
|
|
iter->trace->wait_pipe(iter);
|
|
|
|
mutex_lock(&iter->mutex);
|
|
|
|
if (signal_pending(current))
|
|
return -EINTR;
|
|
|
|
/*
|
|
* We block until we read something and tracing is disabled.
|
|
* We still block if tracing is disabled, but we have never
|
|
* read anything. This allows a user to cat this file, and
|
|
* then enable tracing. But after we have read something,
|
|
* we give an EOF when tracing is again disabled.
|
|
*
|
|
* iter->pos will be 0 if we haven't read anything.
|
|
*/
|
|
if (!tracing_is_enabled() && iter->pos)
|
|
break;
|
|
}
|
|
|
|
return 1;
|
|
}
|
|
|
|
/*
|
|
* Consumer reader.
|
|
*/
|
|
static ssize_t
|
|
tracing_read_pipe(struct file *filp, char __user *ubuf,
|
|
size_t cnt, loff_t *ppos)
|
|
{
|
|
struct trace_iterator *iter = filp->private_data;
|
|
ssize_t sret;
|
|
|
|
/* return any leftover data */
|
|
sret = trace_seq_to_user(&iter->seq, ubuf, cnt);
|
|
if (sret != -EBUSY)
|
|
return sret;
|
|
|
|
trace_seq_init(&iter->seq);
|
|
|
|
/* copy the tracer to avoid using a global lock all around */
|
|
mutex_lock(&trace_types_lock);
|
|
if (unlikely(iter->trace->name != current_trace->name))
|
|
*iter->trace = *current_trace;
|
|
mutex_unlock(&trace_types_lock);
|
|
|
|
/*
|
|
* Avoid more than one consumer on a single file descriptor
|
|
* This is just a matter of traces coherency, the ring buffer itself
|
|
* is protected.
|
|
*/
|
|
mutex_lock(&iter->mutex);
|
|
if (iter->trace->read) {
|
|
sret = iter->trace->read(iter, filp, ubuf, cnt, ppos);
|
|
if (sret)
|
|
goto out;
|
|
}
|
|
|
|
waitagain:
|
|
sret = tracing_wait_pipe(filp);
|
|
if (sret <= 0)
|
|
goto out;
|
|
|
|
/* stop when tracing is finished */
|
|
if (trace_empty(iter)) {
|
|
sret = 0;
|
|
goto out;
|
|
}
|
|
|
|
if (cnt >= PAGE_SIZE)
|
|
cnt = PAGE_SIZE - 1;
|
|
|
|
/* reset all but tr, trace, and overruns */
|
|
memset(&iter->seq, 0,
|
|
sizeof(struct trace_iterator) -
|
|
offsetof(struct trace_iterator, seq));
|
|
iter->pos = -1;
|
|
|
|
trace_event_read_lock();
|
|
trace_access_lock(iter->cpu_file);
|
|
while (trace_find_next_entry_inc(iter) != NULL) {
|
|
enum print_line_t ret;
|
|
int len = iter->seq.len;
|
|
|
|
ret = print_trace_line(iter);
|
|
if (ret == TRACE_TYPE_PARTIAL_LINE) {
|
|
/* don't print partial lines */
|
|
iter->seq.len = len;
|
|
break;
|
|
}
|
|
if (ret != TRACE_TYPE_NO_CONSUME)
|
|
trace_consume(iter);
|
|
|
|
if (iter->seq.len >= cnt)
|
|
break;
|
|
|
|
/*
|
|
* Setting the full flag means we reached the trace_seq buffer
|
|
* size and we should leave by partial output condition above.
|
|
* One of the trace_seq_* functions is not used properly.
|
|
*/
|
|
WARN_ONCE(iter->seq.full, "full flag set for trace type %d",
|
|
iter->ent->type);
|
|
}
|
|
trace_access_unlock(iter->cpu_file);
|
|
trace_event_read_unlock();
|
|
|
|
/* Now copy what we have to the user */
|
|
sret = trace_seq_to_user(&iter->seq, ubuf, cnt);
|
|
if (iter->seq.readpos >= iter->seq.len)
|
|
trace_seq_init(&iter->seq);
|
|
|
|
/*
|
|
* If there was nothing to send to user, in spite of consuming trace
|
|
* entries, go back to wait for more entries.
|
|
*/
|
|
if (sret == -EBUSY)
|
|
goto waitagain;
|
|
|
|
out:
|
|
mutex_unlock(&iter->mutex);
|
|
|
|
return sret;
|
|
}
|
|
|
|
static void tracing_pipe_buf_release(struct pipe_inode_info *pipe,
|
|
struct pipe_buffer *buf)
|
|
{
|
|
__free_page(buf->page);
|
|
}
|
|
|
|
static void tracing_spd_release_pipe(struct splice_pipe_desc *spd,
|
|
unsigned int idx)
|
|
{
|
|
__free_page(spd->pages[idx]);
|
|
}
|
|
|
|
static const struct pipe_buf_operations tracing_pipe_buf_ops = {
|
|
.can_merge = 0,
|
|
.map = generic_pipe_buf_map,
|
|
.unmap = generic_pipe_buf_unmap,
|
|
.confirm = generic_pipe_buf_confirm,
|
|
.release = tracing_pipe_buf_release,
|
|
.steal = generic_pipe_buf_steal,
|
|
.get = generic_pipe_buf_get,
|
|
};
|
|
|
|
static size_t
|
|
tracing_fill_pipe_page(size_t rem, struct trace_iterator *iter)
|
|
{
|
|
size_t count;
|
|
int ret;
|
|
|
|
/* Seq buffer is page-sized, exactly what we need. */
|
|
for (;;) {
|
|
count = iter->seq.len;
|
|
ret = print_trace_line(iter);
|
|
count = iter->seq.len - count;
|
|
if (rem < count) {
|
|
rem = 0;
|
|
iter->seq.len -= count;
|
|
break;
|
|
}
|
|
if (ret == TRACE_TYPE_PARTIAL_LINE) {
|
|
iter->seq.len -= count;
|
|
break;
|
|
}
|
|
|
|
if (ret != TRACE_TYPE_NO_CONSUME)
|
|
trace_consume(iter);
|
|
rem -= count;
|
|
if (!trace_find_next_entry_inc(iter)) {
|
|
rem = 0;
|
|
iter->ent = NULL;
|
|
break;
|
|
}
|
|
}
|
|
|
|
return rem;
|
|
}
|
|
|
|
static ssize_t tracing_splice_read_pipe(struct file *filp,
|
|
loff_t *ppos,
|
|
struct pipe_inode_info *pipe,
|
|
size_t len,
|
|
unsigned int flags)
|
|
{
|
|
struct page *pages_def[PIPE_DEF_BUFFERS];
|
|
struct partial_page partial_def[PIPE_DEF_BUFFERS];
|
|
struct trace_iterator *iter = filp->private_data;
|
|
struct splice_pipe_desc spd = {
|
|
.pages = pages_def,
|
|
.partial = partial_def,
|
|
.nr_pages = 0, /* This gets updated below. */
|
|
.nr_pages_max = PIPE_DEF_BUFFERS,
|
|
.flags = flags,
|
|
.ops = &tracing_pipe_buf_ops,
|
|
.spd_release = tracing_spd_release_pipe,
|
|
};
|
|
ssize_t ret;
|
|
size_t rem;
|
|
unsigned int i;
|
|
|
|
if (splice_grow_spd(pipe, &spd))
|
|
return -ENOMEM;
|
|
|
|
/* copy the tracer to avoid using a global lock all around */
|
|
mutex_lock(&trace_types_lock);
|
|
if (unlikely(iter->trace->name != current_trace->name))
|
|
*iter->trace = *current_trace;
|
|
mutex_unlock(&trace_types_lock);
|
|
|
|
mutex_lock(&iter->mutex);
|
|
|
|
if (iter->trace->splice_read) {
|
|
ret = iter->trace->splice_read(iter, filp,
|
|
ppos, pipe, len, flags);
|
|
if (ret)
|
|
goto out_err;
|
|
}
|
|
|
|
ret = tracing_wait_pipe(filp);
|
|
if (ret <= 0)
|
|
goto out_err;
|
|
|
|
if (!iter->ent && !trace_find_next_entry_inc(iter)) {
|
|
ret = -EFAULT;
|
|
goto out_err;
|
|
}
|
|
|
|
trace_event_read_lock();
|
|
trace_access_lock(iter->cpu_file);
|
|
|
|
/* Fill as many pages as possible. */
|
|
for (i = 0, rem = len; i < pipe->buffers && rem; i++) {
|
|
spd.pages[i] = alloc_page(GFP_KERNEL);
|
|
if (!spd.pages[i])
|
|
break;
|
|
|
|
rem = tracing_fill_pipe_page(rem, iter);
|
|
|
|
/* Copy the data into the page, so we can start over. */
|
|
ret = trace_seq_to_buffer(&iter->seq,
|
|
page_address(spd.pages[i]),
|
|
iter->seq.len);
|
|
if (ret < 0) {
|
|
__free_page(spd.pages[i]);
|
|
break;
|
|
}
|
|
spd.partial[i].offset = 0;
|
|
spd.partial[i].len = iter->seq.len;
|
|
|
|
trace_seq_init(&iter->seq);
|
|
}
|
|
|
|
trace_access_unlock(iter->cpu_file);
|
|
trace_event_read_unlock();
|
|
mutex_unlock(&iter->mutex);
|
|
|
|
spd.nr_pages = i;
|
|
|
|
ret = splice_to_pipe(pipe, &spd);
|
|
out:
|
|
splice_shrink_spd(&spd);
|
|
return ret;
|
|
|
|
out_err:
|
|
mutex_unlock(&iter->mutex);
|
|
goto out;
|
|
}
|
|
|
|
struct ftrace_entries_info {
|
|
struct trace_array *tr;
|
|
int cpu;
|
|
};
|
|
|
|
static int tracing_entries_open(struct inode *inode, struct file *filp)
|
|
{
|
|
struct ftrace_entries_info *info;
|
|
|
|
if (tracing_disabled)
|
|
return -ENODEV;
|
|
|
|
info = kzalloc(sizeof(*info), GFP_KERNEL);
|
|
if (!info)
|
|
return -ENOMEM;
|
|
|
|
info->tr = &global_trace;
|
|
info->cpu = (unsigned long)inode->i_private;
|
|
|
|
filp->private_data = info;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static ssize_t
|
|
tracing_entries_read(struct file *filp, char __user *ubuf,
|
|
size_t cnt, loff_t *ppos)
|
|
{
|
|
struct ftrace_entries_info *info = filp->private_data;
|
|
struct trace_array *tr = info->tr;
|
|
char buf[64];
|
|
int r = 0;
|
|
ssize_t ret;
|
|
|
|
mutex_lock(&trace_types_lock);
|
|
|
|
if (info->cpu == RING_BUFFER_ALL_CPUS) {
|
|
int cpu, buf_size_same;
|
|
unsigned long size;
|
|
|
|
size = 0;
|
|
buf_size_same = 1;
|
|
/* check if all cpu sizes are same */
|
|
for_each_tracing_cpu(cpu) {
|
|
/* fill in the size from first enabled cpu */
|
|
if (size == 0)
|
|
size = tr->data[cpu]->entries;
|
|
if (size != tr->data[cpu]->entries) {
|
|
buf_size_same = 0;
|
|
break;
|
|
}
|
|
}
|
|
|
|
if (buf_size_same) {
|
|
if (!ring_buffer_expanded)
|
|
r = sprintf(buf, "%lu (expanded: %lu)\n",
|
|
size >> 10,
|
|
trace_buf_size >> 10);
|
|
else
|
|
r = sprintf(buf, "%lu\n", size >> 10);
|
|
} else
|
|
r = sprintf(buf, "X\n");
|
|
} else
|
|
r = sprintf(buf, "%lu\n", tr->data[info->cpu]->entries >> 10);
|
|
|
|
mutex_unlock(&trace_types_lock);
|
|
|
|
ret = simple_read_from_buffer(ubuf, cnt, ppos, buf, r);
|
|
return ret;
|
|
}
|
|
|
|
static ssize_t
|
|
tracing_entries_write(struct file *filp, const char __user *ubuf,
|
|
size_t cnt, loff_t *ppos)
|
|
{
|
|
struct ftrace_entries_info *info = filp->private_data;
|
|
unsigned long val;
|
|
int ret;
|
|
|
|
ret = kstrtoul_from_user(ubuf, cnt, 10, &val);
|
|
if (ret)
|
|
return ret;
|
|
|
|
/* must have at least 1 entry */
|
|
if (!val)
|
|
return -EINVAL;
|
|
|
|
/* value is in KB */
|
|
val <<= 10;
|
|
|
|
ret = tracing_resize_ring_buffer(val, info->cpu);
|
|
if (ret < 0)
|
|
return ret;
|
|
|
|
*ppos += cnt;
|
|
|
|
return cnt;
|
|
}
|
|
|
|
static int
|
|
tracing_entries_release(struct inode *inode, struct file *filp)
|
|
{
|
|
struct ftrace_entries_info *info = filp->private_data;
|
|
|
|
kfree(info);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static ssize_t
|
|
tracing_total_entries_read(struct file *filp, char __user *ubuf,
|
|
size_t cnt, loff_t *ppos)
|
|
{
|
|
struct trace_array *tr = filp->private_data;
|
|
char buf[64];
|
|
int r, cpu;
|
|
unsigned long size = 0, expanded_size = 0;
|
|
|
|
mutex_lock(&trace_types_lock);
|
|
for_each_tracing_cpu(cpu) {
|
|
size += tr->data[cpu]->entries >> 10;
|
|
if (!ring_buffer_expanded)
|
|
expanded_size += trace_buf_size >> 10;
|
|
}
|
|
if (ring_buffer_expanded)
|
|
r = sprintf(buf, "%lu\n", size);
|
|
else
|
|
r = sprintf(buf, "%lu (expanded: %lu)\n", size, expanded_size);
|
|
mutex_unlock(&trace_types_lock);
|
|
|
|
return simple_read_from_buffer(ubuf, cnt, ppos, buf, r);
|
|
}
|
|
|
|
static ssize_t
|
|
tracing_free_buffer_write(struct file *filp, const char __user *ubuf,
|
|
size_t cnt, loff_t *ppos)
|
|
{
|
|
/*
|
|
* There is no need to read what the user has written, this function
|
|
* is just to make sure that there is no error when "echo" is used
|
|
*/
|
|
|
|
*ppos += cnt;
|
|
|
|
return cnt;
|
|
}
|
|
|
|
static int
|
|
tracing_free_buffer_release(struct inode *inode, struct file *filp)
|
|
{
|
|
/* disable tracing ? */
|
|
if (trace_flags & TRACE_ITER_STOP_ON_FREE)
|
|
tracing_off();
|
|
/* resize the ring buffer to 0 */
|
|
tracing_resize_ring_buffer(0, RING_BUFFER_ALL_CPUS);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static ssize_t
|
|
tracing_mark_write(struct file *filp, const char __user *ubuf,
|
|
size_t cnt, loff_t *fpos)
|
|
{
|
|
unsigned long addr = (unsigned long)ubuf;
|
|
struct ring_buffer_event *event;
|
|
struct ring_buffer *buffer;
|
|
struct print_entry *entry;
|
|
unsigned long irq_flags;
|
|
struct page *pages[2];
|
|
void *map_page[2];
|
|
int nr_pages = 1;
|
|
ssize_t written;
|
|
int offset;
|
|
int size;
|
|
int len;
|
|
int ret;
|
|
int i;
|
|
|
|
if (tracing_disabled)
|
|
return -EINVAL;
|
|
|
|
if (!(trace_flags & TRACE_ITER_MARKERS))
|
|
return -EINVAL;
|
|
|
|
if (cnt > TRACE_BUF_SIZE)
|
|
cnt = TRACE_BUF_SIZE;
|
|
|
|
/*
|
|
* Userspace is injecting traces into the kernel trace buffer.
|
|
* We want to be as non intrusive as possible.
|
|
* To do so, we do not want to allocate any special buffers
|
|
* or take any locks, but instead write the userspace data
|
|
* straight into the ring buffer.
|
|
*
|
|
* First we need to pin the userspace buffer into memory,
|
|
* which, most likely it is, because it just referenced it.
|
|
* But there's no guarantee that it is. By using get_user_pages_fast()
|
|
* and kmap_atomic/kunmap_atomic() we can get access to the
|
|
* pages directly. We then write the data directly into the
|
|
* ring buffer.
|
|
*/
|
|
BUILD_BUG_ON(TRACE_BUF_SIZE >= PAGE_SIZE);
|
|
|
|
/* check if we cross pages */
|
|
if ((addr & PAGE_MASK) != ((addr + cnt) & PAGE_MASK))
|
|
nr_pages = 2;
|
|
|
|
offset = addr & (PAGE_SIZE - 1);
|
|
addr &= PAGE_MASK;
|
|
|
|
ret = get_user_pages_fast(addr, nr_pages, 0, pages);
|
|
if (ret < nr_pages) {
|
|
while (--ret >= 0)
|
|
put_page(pages[ret]);
|
|
written = -EFAULT;
|
|
goto out;
|
|
}
|
|
|
|
for (i = 0; i < nr_pages; i++)
|
|
map_page[i] = kmap_atomic(pages[i]);
|
|
|
|
local_save_flags(irq_flags);
|
|
size = sizeof(*entry) + cnt + 2; /* possible \n added */
|
|
buffer = global_trace.buffer;
|
|
event = trace_buffer_lock_reserve(buffer, TRACE_PRINT, size,
|
|
irq_flags, preempt_count());
|
|
if (!event) {
|
|
/* Ring buffer disabled, return as if not open for write */
|
|
written = -EBADF;
|
|
goto out_unlock;
|
|
}
|
|
|
|
entry = ring_buffer_event_data(event);
|
|
entry->ip = _THIS_IP_;
|
|
|
|
if (nr_pages == 2) {
|
|
len = PAGE_SIZE - offset;
|
|
memcpy(&entry->buf, map_page[0] + offset, len);
|
|
memcpy(&entry->buf[len], map_page[1], cnt - len);
|
|
} else
|
|
memcpy(&entry->buf, map_page[0] + offset, cnt);
|
|
|
|
if (entry->buf[cnt - 1] != '\n') {
|
|
entry->buf[cnt] = '\n';
|
|
entry->buf[cnt + 1] = '\0';
|
|
} else
|
|
entry->buf[cnt] = '\0';
|
|
|
|
__buffer_unlock_commit(buffer, event);
|
|
|
|
written = cnt;
|
|
|
|
*fpos += written;
|
|
|
|
out_unlock:
|
|
for (i = 0; i < nr_pages; i++){
|
|
kunmap_atomic(map_page[i]);
|
|
put_page(pages[i]);
|
|
}
|
|
out:
|
|
return written;
|
|
}
|
|
|
|
static int tracing_clock_show(struct seq_file *m, void *v)
|
|
{
|
|
int i;
|
|
|
|
for (i = 0; i < ARRAY_SIZE(trace_clocks); i++)
|
|
seq_printf(m,
|
|
"%s%s%s%s", i ? " " : "",
|
|
i == trace_clock_id ? "[" : "", trace_clocks[i].name,
|
|
i == trace_clock_id ? "]" : "");
|
|
seq_putc(m, '\n');
|
|
|
|
return 0;
|
|
}
|
|
|
|
static ssize_t tracing_clock_write(struct file *filp, const char __user *ubuf,
|
|
size_t cnt, loff_t *fpos)
|
|
{
|
|
char buf[64];
|
|
const char *clockstr;
|
|
int i;
|
|
|
|
if (cnt >= sizeof(buf))
|
|
return -EINVAL;
|
|
|
|
if (copy_from_user(&buf, ubuf, cnt))
|
|
return -EFAULT;
|
|
|
|
buf[cnt] = 0;
|
|
|
|
clockstr = strstrip(buf);
|
|
|
|
for (i = 0; i < ARRAY_SIZE(trace_clocks); i++) {
|
|
if (strcmp(trace_clocks[i].name, clockstr) == 0)
|
|
break;
|
|
}
|
|
if (i == ARRAY_SIZE(trace_clocks))
|
|
return -EINVAL;
|
|
|
|
trace_clock_id = i;
|
|
|
|
mutex_lock(&trace_types_lock);
|
|
|
|
ring_buffer_set_clock(global_trace.buffer, trace_clocks[i].func);
|
|
if (max_tr.buffer)
|
|
ring_buffer_set_clock(max_tr.buffer, trace_clocks[i].func);
|
|
|
|
/*
|
|
* New clock may not be consistent with the previous clock.
|
|
* Reset the buffer so that it doesn't have incomparable timestamps.
|
|
*/
|
|
tracing_reset_online_cpus(&global_trace);
|
|
tracing_reset_online_cpus(&max_tr);
|
|
|
|
mutex_unlock(&trace_types_lock);
|
|
|
|
*fpos += cnt;
|
|
|
|
return cnt;
|
|
}
|
|
|
|
static int tracing_clock_open(struct inode *inode, struct file *file)
|
|
{
|
|
if (tracing_disabled)
|
|
return -ENODEV;
|
|
return single_open(file, tracing_clock_show, NULL);
|
|
}
|
|
|
|
#ifdef CONFIG_TRACER_SNAPSHOT
|
|
static int tracing_snapshot_open(struct inode *inode, struct file *file)
|
|
{
|
|
struct trace_iterator *iter;
|
|
int ret = 0;
|
|
|
|
if (file->f_mode & FMODE_READ) {
|
|
iter = __tracing_open(inode, file, true);
|
|
if (IS_ERR(iter))
|
|
ret = PTR_ERR(iter);
|
|
}
|
|
return ret;
|
|
}
|
|
|
|
static ssize_t
|
|
tracing_snapshot_write(struct file *filp, const char __user *ubuf, size_t cnt,
|
|
loff_t *ppos)
|
|
{
|
|
unsigned long val;
|
|
int ret;
|
|
|
|
ret = tracing_update_buffers();
|
|
if (ret < 0)
|
|
return ret;
|
|
|
|
ret = kstrtoul_from_user(ubuf, cnt, 10, &val);
|
|
if (ret)
|
|
return ret;
|
|
|
|
mutex_lock(&trace_types_lock);
|
|
|
|
if (current_trace->use_max_tr) {
|
|
ret = -EBUSY;
|
|
goto out;
|
|
}
|
|
|
|
switch (val) {
|
|
case 0:
|
|
if (current_trace->allocated_snapshot) {
|
|
/* free spare buffer */
|
|
ring_buffer_resize(max_tr.buffer, 1,
|
|
RING_BUFFER_ALL_CPUS);
|
|
set_buffer_entries(&max_tr, 1);
|
|
tracing_reset_online_cpus(&max_tr);
|
|
current_trace->allocated_snapshot = false;
|
|
}
|
|
break;
|
|
case 1:
|
|
if (!current_trace->allocated_snapshot) {
|
|
/* allocate spare buffer */
|
|
ret = resize_buffer_duplicate_size(&max_tr,
|
|
&global_trace, RING_BUFFER_ALL_CPUS);
|
|
if (ret < 0)
|
|
break;
|
|
current_trace->allocated_snapshot = true;
|
|
}
|
|
|
|
local_irq_disable();
|
|
/* Now, we're going to swap */
|
|
update_max_tr(&global_trace, current, smp_processor_id());
|
|
local_irq_enable();
|
|
break;
|
|
default:
|
|
if (current_trace->allocated_snapshot)
|
|
tracing_reset_online_cpus(&max_tr);
|
|
break;
|
|
}
|
|
|
|
if (ret >= 0) {
|
|
*ppos += cnt;
|
|
ret = cnt;
|
|
}
|
|
out:
|
|
mutex_unlock(&trace_types_lock);
|
|
return ret;
|
|
}
|
|
#endif /* CONFIG_TRACER_SNAPSHOT */
|
|
|
|
|
|
static const struct file_operations tracing_max_lat_fops = {
|
|
.open = tracing_open_generic,
|
|
.read = tracing_max_lat_read,
|
|
.write = tracing_max_lat_write,
|
|
.llseek = generic_file_llseek,
|
|
};
|
|
|
|
static const struct file_operations set_tracer_fops = {
|
|
.open = tracing_open_generic,
|
|
.read = tracing_set_trace_read,
|
|
.write = tracing_set_trace_write,
|
|
.llseek = generic_file_llseek,
|
|
};
|
|
|
|
static const struct file_operations tracing_pipe_fops = {
|
|
.open = tracing_open_pipe,
|
|
.poll = tracing_poll_pipe,
|
|
.read = tracing_read_pipe,
|
|
.splice_read = tracing_splice_read_pipe,
|
|
.release = tracing_release_pipe,
|
|
.llseek = no_llseek,
|
|
};
|
|
|
|
static const struct file_operations tracing_entries_fops = {
|
|
.open = tracing_entries_open,
|
|
.read = tracing_entries_read,
|
|
.write = tracing_entries_write,
|
|
.release = tracing_entries_release,
|
|
.llseek = generic_file_llseek,
|
|
};
|
|
|
|
static const struct file_operations tracing_total_entries_fops = {
|
|
.open = tracing_open_generic,
|
|
.read = tracing_total_entries_read,
|
|
.llseek = generic_file_llseek,
|
|
};
|
|
|
|
static const struct file_operations tracing_free_buffer_fops = {
|
|
.write = tracing_free_buffer_write,
|
|
.release = tracing_free_buffer_release,
|
|
};
|
|
|
|
static const struct file_operations tracing_mark_fops = {
|
|
.open = tracing_open_generic,
|
|
.write = tracing_mark_write,
|
|
.llseek = generic_file_llseek,
|
|
};
|
|
|
|
static const struct file_operations trace_clock_fops = {
|
|
.open = tracing_clock_open,
|
|
.read = seq_read,
|
|
.llseek = seq_lseek,
|
|
.release = single_release,
|
|
.write = tracing_clock_write,
|
|
};
|
|
|
|
#ifdef CONFIG_TRACER_SNAPSHOT
|
|
static const struct file_operations snapshot_fops = {
|
|
.open = tracing_snapshot_open,
|
|
.read = seq_read,
|
|
.write = tracing_snapshot_write,
|
|
.llseek = tracing_seek,
|
|
.release = tracing_release,
|
|
};
|
|
#endif /* CONFIG_TRACER_SNAPSHOT */
|
|
|
|
struct ftrace_buffer_info {
|
|
struct trace_array *tr;
|
|
void *spare;
|
|
int cpu;
|
|
unsigned int read;
|
|
};
|
|
|
|
static int tracing_buffers_open(struct inode *inode, struct file *filp)
|
|
{
|
|
int cpu = (int)(long)inode->i_private;
|
|
struct ftrace_buffer_info *info;
|
|
|
|
if (tracing_disabled)
|
|
return -ENODEV;
|
|
|
|
info = kzalloc(sizeof(*info), GFP_KERNEL);
|
|
if (!info)
|
|
return -ENOMEM;
|
|
|
|
info->tr = &global_trace;
|
|
info->cpu = cpu;
|
|
info->spare = NULL;
|
|
/* Force reading ring buffer for first read */
|
|
info->read = (unsigned int)-1;
|
|
|
|
filp->private_data = info;
|
|
|
|
return nonseekable_open(inode, filp);
|
|
}
|
|
|
|
static ssize_t
|
|
tracing_buffers_read(struct file *filp, char __user *ubuf,
|
|
size_t count, loff_t *ppos)
|
|
{
|
|
struct ftrace_buffer_info *info = filp->private_data;
|
|
ssize_t ret;
|
|
size_t size;
|
|
|
|
if (!count)
|
|
return 0;
|
|
|
|
if (!info->spare)
|
|
info->spare = ring_buffer_alloc_read_page(info->tr->buffer, info->cpu);
|
|
if (!info->spare)
|
|
return -ENOMEM;
|
|
|
|
/* Do we have previous read data to read? */
|
|
if (info->read < PAGE_SIZE)
|
|
goto read;
|
|
|
|
trace_access_lock(info->cpu);
|
|
ret = ring_buffer_read_page(info->tr->buffer,
|
|
&info->spare,
|
|
count,
|
|
info->cpu, 0);
|
|
trace_access_unlock(info->cpu);
|
|
if (ret < 0)
|
|
return 0;
|
|
|
|
info->read = 0;
|
|
|
|
read:
|
|
size = PAGE_SIZE - info->read;
|
|
if (size > count)
|
|
size = count;
|
|
|
|
ret = copy_to_user(ubuf, info->spare + info->read, size);
|
|
if (ret == size)
|
|
return -EFAULT;
|
|
size -= ret;
|
|
|
|
*ppos += size;
|
|
info->read += size;
|
|
|
|
return size;
|
|
}
|
|
|
|
static int tracing_buffers_release(struct inode *inode, struct file *file)
|
|
{
|
|
struct ftrace_buffer_info *info = file->private_data;
|
|
|
|
if (info->spare)
|
|
ring_buffer_free_read_page(info->tr->buffer, info->spare);
|
|
kfree(info);
|
|
|
|
return 0;
|
|
}
|
|
|
|
struct buffer_ref {
|
|
struct ring_buffer *buffer;
|
|
void *page;
|
|
int ref;
|
|
};
|
|
|
|
static void buffer_pipe_buf_release(struct pipe_inode_info *pipe,
|
|
struct pipe_buffer *buf)
|
|
{
|
|
struct buffer_ref *ref = (struct buffer_ref *)buf->private;
|
|
|
|
if (--ref->ref)
|
|
return;
|
|
|
|
ring_buffer_free_read_page(ref->buffer, ref->page);
|
|
kfree(ref);
|
|
buf->private = 0;
|
|
}
|
|
|
|
static void buffer_pipe_buf_get(struct pipe_inode_info *pipe,
|
|
struct pipe_buffer *buf)
|
|
{
|
|
struct buffer_ref *ref = (struct buffer_ref *)buf->private;
|
|
|
|
ref->ref++;
|
|
}
|
|
|
|
/* Pipe buffer operations for a buffer. */
|
|
static const struct pipe_buf_operations buffer_pipe_buf_ops = {
|
|
.can_merge = 0,
|
|
.map = generic_pipe_buf_map,
|
|
.unmap = generic_pipe_buf_unmap,
|
|
.confirm = generic_pipe_buf_confirm,
|
|
.release = buffer_pipe_buf_release,
|
|
.steal = generic_pipe_buf_steal,
|
|
.get = buffer_pipe_buf_get,
|
|
};
|
|
|
|
/*
|
|
* Callback from splice_to_pipe(), if we need to release some pages
|
|
* at the end of the spd in case we error'ed out in filling the pipe.
|
|
*/
|
|
static void buffer_spd_release(struct splice_pipe_desc *spd, unsigned int i)
|
|
{
|
|
struct buffer_ref *ref =
|
|
(struct buffer_ref *)spd->partial[i].private;
|
|
|
|
if (--ref->ref)
|
|
return;
|
|
|
|
ring_buffer_free_read_page(ref->buffer, ref->page);
|
|
kfree(ref);
|
|
spd->partial[i].private = 0;
|
|
}
|
|
|
|
static ssize_t
|
|
tracing_buffers_splice_read(struct file *file, loff_t *ppos,
|
|
struct pipe_inode_info *pipe, size_t len,
|
|
unsigned int flags)
|
|
{
|
|
struct ftrace_buffer_info *info = file->private_data;
|
|
struct partial_page partial_def[PIPE_DEF_BUFFERS];
|
|
struct page *pages_def[PIPE_DEF_BUFFERS];
|
|
struct splice_pipe_desc spd = {
|
|
.pages = pages_def,
|
|
.partial = partial_def,
|
|
.nr_pages_max = PIPE_DEF_BUFFERS,
|
|
.flags = flags,
|
|
.ops = &buffer_pipe_buf_ops,
|
|
.spd_release = buffer_spd_release,
|
|
};
|
|
struct buffer_ref *ref;
|
|
int entries, size, i;
|
|
size_t ret;
|
|
|
|
if (splice_grow_spd(pipe, &spd))
|
|
return -ENOMEM;
|
|
|
|
if (*ppos & (PAGE_SIZE - 1)) {
|
|
ret = -EINVAL;
|
|
goto out;
|
|
}
|
|
|
|
if (len & (PAGE_SIZE - 1)) {
|
|
if (len < PAGE_SIZE) {
|
|
ret = -EINVAL;
|
|
goto out;
|
|
}
|
|
len &= PAGE_MASK;
|
|
}
|
|
|
|
trace_access_lock(info->cpu);
|
|
entries = ring_buffer_entries_cpu(info->tr->buffer, info->cpu);
|
|
|
|
for (i = 0; i < pipe->buffers && len && entries; i++, len -= PAGE_SIZE) {
|
|
struct page *page;
|
|
int r;
|
|
|
|
ref = kzalloc(sizeof(*ref), GFP_KERNEL);
|
|
if (!ref)
|
|
break;
|
|
|
|
ref->ref = 1;
|
|
ref->buffer = info->tr->buffer;
|
|
ref->page = ring_buffer_alloc_read_page(ref->buffer, info->cpu);
|
|
if (!ref->page) {
|
|
kfree(ref);
|
|
break;
|
|
}
|
|
|
|
r = ring_buffer_read_page(ref->buffer, &ref->page,
|
|
len, info->cpu, 1);
|
|
if (r < 0) {
|
|
ring_buffer_free_read_page(ref->buffer, ref->page);
|
|
kfree(ref);
|
|
break;
|
|
}
|
|
|
|
/*
|
|
* zero out any left over data, this is going to
|
|
* user land.
|
|
*/
|
|
size = ring_buffer_page_len(ref->page);
|
|
if (size < PAGE_SIZE)
|
|
memset(ref->page + size, 0, PAGE_SIZE - size);
|
|
|
|
page = virt_to_page(ref->page);
|
|
|
|
spd.pages[i] = page;
|
|
spd.partial[i].len = PAGE_SIZE;
|
|
spd.partial[i].offset = 0;
|
|
spd.partial[i].private = (unsigned long)ref;
|
|
spd.nr_pages++;
|
|
*ppos += PAGE_SIZE;
|
|
|
|
entries = ring_buffer_entries_cpu(info->tr->buffer, info->cpu);
|
|
}
|
|
|
|
trace_access_unlock(info->cpu);
|
|
spd.nr_pages = i;
|
|
|
|
/* did we read anything? */
|
|
if (!spd.nr_pages) {
|
|
if (flags & SPLICE_F_NONBLOCK)
|
|
ret = -EAGAIN;
|
|
else
|
|
ret = 0;
|
|
/* TODO: block */
|
|
goto out;
|
|
}
|
|
|
|
ret = splice_to_pipe(pipe, &spd);
|
|
splice_shrink_spd(&spd);
|
|
out:
|
|
return ret;
|
|
}
|
|
|
|
static const struct file_operations tracing_buffers_fops = {
|
|
.open = tracing_buffers_open,
|
|
.read = tracing_buffers_read,
|
|
.release = tracing_buffers_release,
|
|
.splice_read = tracing_buffers_splice_read,
|
|
.llseek = no_llseek,
|
|
};
|
|
|
|
static ssize_t
|
|
tracing_stats_read(struct file *filp, char __user *ubuf,
|
|
size_t count, loff_t *ppos)
|
|
{
|
|
unsigned long cpu = (unsigned long)filp->private_data;
|
|
struct trace_array *tr = &global_trace;
|
|
struct trace_seq *s;
|
|
unsigned long cnt;
|
|
unsigned long long t;
|
|
unsigned long usec_rem;
|
|
|
|
s = kmalloc(sizeof(*s), GFP_KERNEL);
|
|
if (!s)
|
|
return -ENOMEM;
|
|
|
|
trace_seq_init(s);
|
|
|
|
cnt = ring_buffer_entries_cpu(tr->buffer, cpu);
|
|
trace_seq_printf(s, "entries: %ld\n", cnt);
|
|
|
|
cnt = ring_buffer_overrun_cpu(tr->buffer, cpu);
|
|
trace_seq_printf(s, "overrun: %ld\n", cnt);
|
|
|
|
cnt = ring_buffer_commit_overrun_cpu(tr->buffer, cpu);
|
|
trace_seq_printf(s, "commit overrun: %ld\n", cnt);
|
|
|
|
cnt = ring_buffer_bytes_cpu(tr->buffer, cpu);
|
|
trace_seq_printf(s, "bytes: %ld\n", cnt);
|
|
|
|
if (trace_clocks[trace_clock_id].in_ns) {
|
|
/* local or global for trace_clock */
|
|
t = ns2usecs(ring_buffer_oldest_event_ts(tr->buffer, cpu));
|
|
usec_rem = do_div(t, USEC_PER_SEC);
|
|
trace_seq_printf(s, "oldest event ts: %5llu.%06lu\n",
|
|
t, usec_rem);
|
|
|
|
t = ns2usecs(ring_buffer_time_stamp(tr->buffer, cpu));
|
|
usec_rem = do_div(t, USEC_PER_SEC);
|
|
trace_seq_printf(s, "now ts: %5llu.%06lu\n", t, usec_rem);
|
|
} else {
|
|
/* counter or tsc mode for trace_clock */
|
|
trace_seq_printf(s, "oldest event ts: %llu\n",
|
|
ring_buffer_oldest_event_ts(tr->buffer, cpu));
|
|
|
|
trace_seq_printf(s, "now ts: %llu\n",
|
|
ring_buffer_time_stamp(tr->buffer, cpu));
|
|
}
|
|
|
|
cnt = ring_buffer_dropped_events_cpu(tr->buffer, cpu);
|
|
trace_seq_printf(s, "dropped events: %ld\n", cnt);
|
|
|
|
cnt = ring_buffer_read_events_cpu(tr->buffer, cpu);
|
|
trace_seq_printf(s, "read events: %ld\n", cnt);
|
|
|
|
count = simple_read_from_buffer(ubuf, count, ppos, s->buffer, s->len);
|
|
|
|
kfree(s);
|
|
|
|
return count;
|
|
}
|
|
|
|
static const struct file_operations tracing_stats_fops = {
|
|
.open = tracing_open_generic,
|
|
.read = tracing_stats_read,
|
|
.llseek = generic_file_llseek,
|
|
};
|
|
|
|
#ifdef CONFIG_DYNAMIC_FTRACE
|
|
|
|
int __weak ftrace_arch_read_dyn_info(char *buf, int size)
|
|
{
|
|
return 0;
|
|
}
|
|
|
|
static ssize_t
|
|
tracing_read_dyn_info(struct file *filp, char __user *ubuf,
|
|
size_t cnt, loff_t *ppos)
|
|
{
|
|
static char ftrace_dyn_info_buffer[1024];
|
|
static DEFINE_MUTEX(dyn_info_mutex);
|
|
unsigned long *p = filp->private_data;
|
|
char *buf = ftrace_dyn_info_buffer;
|
|
int size = ARRAY_SIZE(ftrace_dyn_info_buffer);
|
|
int r;
|
|
|
|
mutex_lock(&dyn_info_mutex);
|
|
r = sprintf(buf, "%ld ", *p);
|
|
|
|
r += ftrace_arch_read_dyn_info(buf+r, (size-1)-r);
|
|
buf[r++] = '\n';
|
|
|
|
r = simple_read_from_buffer(ubuf, cnt, ppos, buf, r);
|
|
|
|
mutex_unlock(&dyn_info_mutex);
|
|
|
|
return r;
|
|
}
|
|
|
|
static const struct file_operations tracing_dyn_info_fops = {
|
|
.open = tracing_open_generic,
|
|
.read = tracing_read_dyn_info,
|
|
.llseek = generic_file_llseek,
|
|
};
|
|
#endif
|
|
|
|
static struct dentry *d_tracer;
|
|
|
|
struct dentry *tracing_init_dentry(void)
|
|
{
|
|
static int once;
|
|
|
|
if (d_tracer)
|
|
return d_tracer;
|
|
|
|
if (!debugfs_initialized())
|
|
return NULL;
|
|
|
|
d_tracer = debugfs_create_dir("tracing", NULL);
|
|
|
|
if (!d_tracer && !once) {
|
|
once = 1;
|
|
pr_warning("Could not create debugfs directory 'tracing'\n");
|
|
return NULL;
|
|
}
|
|
|
|
return d_tracer;
|
|
}
|
|
|
|
static struct dentry *d_percpu;
|
|
|
|
static struct dentry *tracing_dentry_percpu(void)
|
|
{
|
|
static int once;
|
|
struct dentry *d_tracer;
|
|
|
|
if (d_percpu)
|
|
return d_percpu;
|
|
|
|
d_tracer = tracing_init_dentry();
|
|
|
|
if (!d_tracer)
|
|
return NULL;
|
|
|
|
d_percpu = debugfs_create_dir("per_cpu", d_tracer);
|
|
|
|
if (!d_percpu && !once) {
|
|
once = 1;
|
|
pr_warning("Could not create debugfs directory 'per_cpu'\n");
|
|
return NULL;
|
|
}
|
|
|
|
return d_percpu;
|
|
}
|
|
|
|
static void tracing_init_debugfs_percpu(long cpu)
|
|
{
|
|
struct dentry *d_percpu = tracing_dentry_percpu();
|
|
struct dentry *d_cpu;
|
|
char cpu_dir[30]; /* 30 characters should be more than enough */
|
|
|
|
if (!d_percpu)
|
|
return;
|
|
|
|
snprintf(cpu_dir, 30, "cpu%ld", cpu);
|
|
d_cpu = debugfs_create_dir(cpu_dir, d_percpu);
|
|
if (!d_cpu) {
|
|
pr_warning("Could not create debugfs '%s' entry\n", cpu_dir);
|
|
return;
|
|
}
|
|
|
|
/* per cpu trace_pipe */
|
|
trace_create_file("trace_pipe", 0444, d_cpu,
|
|
(void *) cpu, &tracing_pipe_fops);
|
|
|
|
/* per cpu trace */
|
|
trace_create_file("trace", 0644, d_cpu,
|
|
(void *) cpu, &tracing_fops);
|
|
|
|
trace_create_file("trace_pipe_raw", 0444, d_cpu,
|
|
(void *) cpu, &tracing_buffers_fops);
|
|
|
|
trace_create_file("stats", 0444, d_cpu,
|
|
(void *) cpu, &tracing_stats_fops);
|
|
|
|
trace_create_file("buffer_size_kb", 0444, d_cpu,
|
|
(void *) cpu, &tracing_entries_fops);
|
|
}
|
|
|
|
#ifdef CONFIG_FTRACE_SELFTEST
|
|
/* Let selftest have access to static functions in this file */
|
|
#include "trace_selftest.c"
|
|
#endif
|
|
|
|
struct trace_option_dentry {
|
|
struct tracer_opt *opt;
|
|
struct tracer_flags *flags;
|
|
struct dentry *entry;
|
|
};
|
|
|
|
static ssize_t
|
|
trace_options_read(struct file *filp, char __user *ubuf, size_t cnt,
|
|
loff_t *ppos)
|
|
{
|
|
struct trace_option_dentry *topt = filp->private_data;
|
|
char *buf;
|
|
|
|
if (topt->flags->val & topt->opt->bit)
|
|
buf = "1\n";
|
|
else
|
|
buf = "0\n";
|
|
|
|
return simple_read_from_buffer(ubuf, cnt, ppos, buf, 2);
|
|
}
|
|
|
|
static ssize_t
|
|
trace_options_write(struct file *filp, const char __user *ubuf, size_t cnt,
|
|
loff_t *ppos)
|
|
{
|
|
struct trace_option_dentry *topt = filp->private_data;
|
|
unsigned long val;
|
|
int ret;
|
|
|
|
ret = kstrtoul_from_user(ubuf, cnt, 10, &val);
|
|
if (ret)
|
|
return ret;
|
|
|
|
if (val != 0 && val != 1)
|
|
return -EINVAL;
|
|
|
|
if (!!(topt->flags->val & topt->opt->bit) != val) {
|
|
mutex_lock(&trace_types_lock);
|
|
ret = __set_tracer_option(current_trace, topt->flags,
|
|
topt->opt, !val);
|
|
mutex_unlock(&trace_types_lock);
|
|
if (ret)
|
|
return ret;
|
|
}
|
|
|
|
*ppos += cnt;
|
|
|
|
return cnt;
|
|
}
|
|
|
|
|
|
static const struct file_operations trace_options_fops = {
|
|
.open = tracing_open_generic,
|
|
.read = trace_options_read,
|
|
.write = trace_options_write,
|
|
.llseek = generic_file_llseek,
|
|
};
|
|
|
|
static ssize_t
|
|
trace_options_core_read(struct file *filp, char __user *ubuf, size_t cnt,
|
|
loff_t *ppos)
|
|
{
|
|
long index = (long)filp->private_data;
|
|
char *buf;
|
|
|
|
if (trace_flags & (1 << index))
|
|
buf = "1\n";
|
|
else
|
|
buf = "0\n";
|
|
|
|
return simple_read_from_buffer(ubuf, cnt, ppos, buf, 2);
|
|
}
|
|
|
|
static ssize_t
|
|
trace_options_core_write(struct file *filp, const char __user *ubuf, size_t cnt,
|
|
loff_t *ppos)
|
|
{
|
|
long index = (long)filp->private_data;
|
|
unsigned long val;
|
|
int ret;
|
|
|
|
ret = kstrtoul_from_user(ubuf, cnt, 10, &val);
|
|
if (ret)
|
|
return ret;
|
|
|
|
if (val != 0 && val != 1)
|
|
return -EINVAL;
|
|
|
|
mutex_lock(&trace_types_lock);
|
|
ret = set_tracer_flag(1 << index, val);
|
|
mutex_unlock(&trace_types_lock);
|
|
|
|
if (ret < 0)
|
|
return ret;
|
|
|
|
*ppos += cnt;
|
|
|
|
return cnt;
|
|
}
|
|
|
|
static const struct file_operations trace_options_core_fops = {
|
|
.open = tracing_open_generic,
|
|
.read = trace_options_core_read,
|
|
.write = trace_options_core_write,
|
|
.llseek = generic_file_llseek,
|
|
};
|
|
|
|
struct dentry *trace_create_file(const char *name,
|
|
umode_t mode,
|
|
struct dentry *parent,
|
|
void *data,
|
|
const struct file_operations *fops)
|
|
{
|
|
struct dentry *ret;
|
|
|
|
ret = debugfs_create_file(name, mode, parent, data, fops);
|
|
if (!ret)
|
|
pr_warning("Could not create debugfs '%s' entry\n", name);
|
|
|
|
return ret;
|
|
}
|
|
|
|
|
|
static struct dentry *trace_options_init_dentry(void)
|
|
{
|
|
struct dentry *d_tracer;
|
|
static struct dentry *t_options;
|
|
|
|
if (t_options)
|
|
return t_options;
|
|
|
|
d_tracer = tracing_init_dentry();
|
|
if (!d_tracer)
|
|
return NULL;
|
|
|
|
t_options = debugfs_create_dir("options", d_tracer);
|
|
if (!t_options) {
|
|
pr_warning("Could not create debugfs directory 'options'\n");
|
|
return NULL;
|
|
}
|
|
|
|
return t_options;
|
|
}
|
|
|
|
static void
|
|
create_trace_option_file(struct trace_option_dentry *topt,
|
|
struct tracer_flags *flags,
|
|
struct tracer_opt *opt)
|
|
{
|
|
struct dentry *t_options;
|
|
|
|
t_options = trace_options_init_dentry();
|
|
if (!t_options)
|
|
return;
|
|
|
|
topt->flags = flags;
|
|
topt->opt = opt;
|
|
|
|
topt->entry = trace_create_file(opt->name, 0644, t_options, topt,
|
|
&trace_options_fops);
|
|
|
|
}
|
|
|
|
static struct trace_option_dentry *
|
|
create_trace_option_files(struct tracer *tracer)
|
|
{
|
|
struct trace_option_dentry *topts;
|
|
struct tracer_flags *flags;
|
|
struct tracer_opt *opts;
|
|
int cnt;
|
|
|
|
if (!tracer)
|
|
return NULL;
|
|
|
|
flags = tracer->flags;
|
|
|
|
if (!flags || !flags->opts)
|
|
return NULL;
|
|
|
|
opts = flags->opts;
|
|
|
|
for (cnt = 0; opts[cnt].name; cnt++)
|
|
;
|
|
|
|
topts = kcalloc(cnt + 1, sizeof(*topts), GFP_KERNEL);
|
|
if (!topts)
|
|
return NULL;
|
|
|
|
for (cnt = 0; opts[cnt].name; cnt++)
|
|
create_trace_option_file(&topts[cnt], flags,
|
|
&opts[cnt]);
|
|
|
|
return topts;
|
|
}
|
|
|
|
static void
|
|
destroy_trace_option_files(struct trace_option_dentry *topts)
|
|
{
|
|
int cnt;
|
|
|
|
if (!topts)
|
|
return;
|
|
|
|
for (cnt = 0; topts[cnt].opt; cnt++) {
|
|
if (topts[cnt].entry)
|
|
debugfs_remove(topts[cnt].entry);
|
|
}
|
|
|
|
kfree(topts);
|
|
}
|
|
|
|
static struct dentry *
|
|
create_trace_option_core_file(const char *option, long index)
|
|
{
|
|
struct dentry *t_options;
|
|
|
|
t_options = trace_options_init_dentry();
|
|
if (!t_options)
|
|
return NULL;
|
|
|
|
return trace_create_file(option, 0644, t_options, (void *)index,
|
|
&trace_options_core_fops);
|
|
}
|
|
|
|
static __init void create_trace_options_dir(void)
|
|
{
|
|
struct dentry *t_options;
|
|
int i;
|
|
|
|
t_options = trace_options_init_dentry();
|
|
if (!t_options)
|
|
return;
|
|
|
|
for (i = 0; trace_options[i]; i++)
|
|
create_trace_option_core_file(trace_options[i], i);
|
|
}
|
|
|
|
static ssize_t
|
|
rb_simple_read(struct file *filp, char __user *ubuf,
|
|
size_t cnt, loff_t *ppos)
|
|
{
|
|
struct trace_array *tr = filp->private_data;
|
|
struct ring_buffer *buffer = tr->buffer;
|
|
char buf[64];
|
|
int r;
|
|
|
|
if (buffer)
|
|
r = ring_buffer_record_is_on(buffer);
|
|
else
|
|
r = 0;
|
|
|
|
r = sprintf(buf, "%d\n", r);
|
|
|
|
return simple_read_from_buffer(ubuf, cnt, ppos, buf, r);
|
|
}
|
|
|
|
static ssize_t
|
|
rb_simple_write(struct file *filp, const char __user *ubuf,
|
|
size_t cnt, loff_t *ppos)
|
|
{
|
|
struct trace_array *tr = filp->private_data;
|
|
struct ring_buffer *buffer = tr->buffer;
|
|
unsigned long val;
|
|
int ret;
|
|
|
|
ret = kstrtoul_from_user(ubuf, cnt, 10, &val);
|
|
if (ret)
|
|
return ret;
|
|
|
|
if (buffer) {
|
|
mutex_lock(&trace_types_lock);
|
|
if (val) {
|
|
ring_buffer_record_on(buffer);
|
|
if (current_trace->start)
|
|
current_trace->start(tr);
|
|
} else {
|
|
ring_buffer_record_off(buffer);
|
|
if (current_trace->stop)
|
|
current_trace->stop(tr);
|
|
}
|
|
mutex_unlock(&trace_types_lock);
|
|
}
|
|
|
|
(*ppos)++;
|
|
|
|
return cnt;
|
|
}
|
|
|
|
static const struct file_operations rb_simple_fops = {
|
|
.open = tracing_open_generic,
|
|
.read = rb_simple_read,
|
|
.write = rb_simple_write,
|
|
.llseek = default_llseek,
|
|
};
|
|
|
|
static __init int tracer_init_debugfs(void)
|
|
{
|
|
struct dentry *d_tracer;
|
|
int cpu;
|
|
|
|
trace_access_lock_init();
|
|
|
|
d_tracer = tracing_init_dentry();
|
|
|
|
trace_create_file("trace_options", 0644, d_tracer,
|
|
NULL, &tracing_iter_fops);
|
|
|
|
trace_create_file("tracing_cpumask", 0644, d_tracer,
|
|
NULL, &tracing_cpumask_fops);
|
|
|
|
trace_create_file("trace", 0644, d_tracer,
|
|
(void *) TRACE_PIPE_ALL_CPU, &tracing_fops);
|
|
|
|
trace_create_file("available_tracers", 0444, d_tracer,
|
|
&global_trace, &show_traces_fops);
|
|
|
|
trace_create_file("current_tracer", 0644, d_tracer,
|
|
&global_trace, &set_tracer_fops);
|
|
|
|
#ifdef CONFIG_TRACER_MAX_TRACE
|
|
trace_create_file("tracing_max_latency", 0644, d_tracer,
|
|
&tracing_max_latency, &tracing_max_lat_fops);
|
|
#endif
|
|
|
|
trace_create_file("tracing_thresh", 0644, d_tracer,
|
|
&tracing_thresh, &tracing_max_lat_fops);
|
|
|
|
trace_create_file("README", 0444, d_tracer,
|
|
NULL, &tracing_readme_fops);
|
|
|
|
trace_create_file("trace_pipe", 0444, d_tracer,
|
|
(void *) TRACE_PIPE_ALL_CPU, &tracing_pipe_fops);
|
|
|
|
trace_create_file("buffer_size_kb", 0644, d_tracer,
|
|
(void *) RING_BUFFER_ALL_CPUS, &tracing_entries_fops);
|
|
|
|
trace_create_file("buffer_total_size_kb", 0444, d_tracer,
|
|
&global_trace, &tracing_total_entries_fops);
|
|
|
|
trace_create_file("free_buffer", 0644, d_tracer,
|
|
&global_trace, &tracing_free_buffer_fops);
|
|
|
|
trace_create_file("trace_marker", 0220, d_tracer,
|
|
NULL, &tracing_mark_fops);
|
|
|
|
trace_create_file("saved_cmdlines", 0444, d_tracer,
|
|
NULL, &tracing_saved_cmdlines_fops);
|
|
|
|
trace_create_file("trace_clock", 0644, d_tracer, NULL,
|
|
&trace_clock_fops);
|
|
|
|
trace_create_file("tracing_on", 0644, d_tracer,
|
|
&global_trace, &rb_simple_fops);
|
|
|
|
#ifdef CONFIG_DYNAMIC_FTRACE
|
|
trace_create_file("dyn_ftrace_total_info", 0444, d_tracer,
|
|
&ftrace_update_tot_cnt, &tracing_dyn_info_fops);
|
|
#endif
|
|
|
|
#ifdef CONFIG_TRACER_SNAPSHOT
|
|
trace_create_file("snapshot", 0644, d_tracer,
|
|
(void *) TRACE_PIPE_ALL_CPU, &snapshot_fops);
|
|
#endif
|
|
|
|
create_trace_options_dir();
|
|
|
|
for_each_tracing_cpu(cpu)
|
|
tracing_init_debugfs_percpu(cpu);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int trace_panic_handler(struct notifier_block *this,
|
|
unsigned long event, void *unused)
|
|
{
|
|
if (ftrace_dump_on_oops)
|
|
ftrace_dump(ftrace_dump_on_oops);
|
|
return NOTIFY_OK;
|
|
}
|
|
|
|
static struct notifier_block trace_panic_notifier = {
|
|
.notifier_call = trace_panic_handler,
|
|
.next = NULL,
|
|
.priority = 150 /* priority: INT_MAX >= x >= 0 */
|
|
};
|
|
|
|
static int trace_die_handler(struct notifier_block *self,
|
|
unsigned long val,
|
|
void *data)
|
|
{
|
|
switch (val) {
|
|
case DIE_OOPS:
|
|
if (ftrace_dump_on_oops)
|
|
ftrace_dump(ftrace_dump_on_oops);
|
|
break;
|
|
default:
|
|
break;
|
|
}
|
|
return NOTIFY_OK;
|
|
}
|
|
|
|
static struct notifier_block trace_die_notifier = {
|
|
.notifier_call = trace_die_handler,
|
|
.priority = 200
|
|
};
|
|
|
|
/*
|
|
* printk is set to max of 1024, we really don't need it that big.
|
|
* Nothing should be printing 1000 characters anyway.
|
|
*/
|
|
#define TRACE_MAX_PRINT 1000
|
|
|
|
/*
|
|
* Define here KERN_TRACE so that we have one place to modify
|
|
* it if we decide to change what log level the ftrace dump
|
|
* should be at.
|
|
*/
|
|
#define KERN_TRACE KERN_EMERG
|
|
|
|
void
|
|
trace_printk_seq(struct trace_seq *s)
|
|
{
|
|
/* Probably should print a warning here. */
|
|
if (s->len >= 1000)
|
|
s->len = 1000;
|
|
|
|
/* should be zero ended, but we are paranoid. */
|
|
s->buffer[s->len] = 0;
|
|
|
|
printk(KERN_TRACE "%s", s->buffer);
|
|
|
|
trace_seq_init(s);
|
|
}
|
|
|
|
void trace_init_global_iter(struct trace_iterator *iter)
|
|
{
|
|
iter->tr = &global_trace;
|
|
iter->trace = current_trace;
|
|
iter->cpu_file = TRACE_PIPE_ALL_CPU;
|
|
}
|
|
|
|
static void
|
|
__ftrace_dump(bool disable_tracing, enum ftrace_dump_mode oops_dump_mode)
|
|
{
|
|
static arch_spinlock_t ftrace_dump_lock =
|
|
(arch_spinlock_t)__ARCH_SPIN_LOCK_UNLOCKED;
|
|
/* use static because iter can be a bit big for the stack */
|
|
static struct trace_iterator iter;
|
|
unsigned int old_userobj;
|
|
static int dump_ran;
|
|
unsigned long flags;
|
|
int cnt = 0, cpu;
|
|
|
|
/* only one dump */
|
|
local_irq_save(flags);
|
|
arch_spin_lock(&ftrace_dump_lock);
|
|
if (dump_ran)
|
|
goto out;
|
|
|
|
dump_ran = 1;
|
|
|
|
tracing_off();
|
|
|
|
/* Did function tracer already get disabled? */
|
|
if (ftrace_is_dead()) {
|
|
printk("# WARNING: FUNCTION TRACING IS CORRUPTED\n");
|
|
printk("# MAY BE MISSING FUNCTION EVENTS\n");
|
|
}
|
|
|
|
if (disable_tracing)
|
|
ftrace_kill();
|
|
|
|
/* Simulate the iterator */
|
|
trace_init_global_iter(&iter);
|
|
|
|
for_each_tracing_cpu(cpu) {
|
|
atomic_inc(&iter.tr->data[cpu]->disabled);
|
|
}
|
|
|
|
old_userobj = trace_flags & TRACE_ITER_SYM_USEROBJ;
|
|
|
|
/* don't look at user memory in panic mode */
|
|
trace_flags &= ~TRACE_ITER_SYM_USEROBJ;
|
|
|
|
switch (oops_dump_mode) {
|
|
case DUMP_ALL:
|
|
iter.cpu_file = TRACE_PIPE_ALL_CPU;
|
|
break;
|
|
case DUMP_ORIG:
|
|
iter.cpu_file = raw_smp_processor_id();
|
|
break;
|
|
case DUMP_NONE:
|
|
goto out_enable;
|
|
default:
|
|
printk(KERN_TRACE "Bad dumping mode, switching to all CPUs dump\n");
|
|
iter.cpu_file = TRACE_PIPE_ALL_CPU;
|
|
}
|
|
|
|
printk(KERN_TRACE "Dumping ftrace buffer:\n");
|
|
|
|
/*
|
|
* We need to stop all tracing on all CPUS to read the
|
|
* the next buffer. This is a bit expensive, but is
|
|
* not done often. We fill all what we can read,
|
|
* and then release the locks again.
|
|
*/
|
|
|
|
while (!trace_empty(&iter)) {
|
|
|
|
if (!cnt)
|
|
printk(KERN_TRACE "---------------------------------\n");
|
|
|
|
cnt++;
|
|
|
|
/* reset all but tr, trace, and overruns */
|
|
memset(&iter.seq, 0,
|
|
sizeof(struct trace_iterator) -
|
|
offsetof(struct trace_iterator, seq));
|
|
iter.iter_flags |= TRACE_FILE_LAT_FMT;
|
|
iter.pos = -1;
|
|
|
|
if (trace_find_next_entry_inc(&iter) != NULL) {
|
|
int ret;
|
|
|
|
ret = print_trace_line(&iter);
|
|
if (ret != TRACE_TYPE_NO_CONSUME)
|
|
trace_consume(&iter);
|
|
}
|
|
touch_nmi_watchdog();
|
|
|
|
trace_printk_seq(&iter.seq);
|
|
}
|
|
|
|
if (!cnt)
|
|
printk(KERN_TRACE " (ftrace buffer empty)\n");
|
|
else
|
|
printk(KERN_TRACE "---------------------------------\n");
|
|
|
|
out_enable:
|
|
/* Re-enable tracing if requested */
|
|
if (!disable_tracing) {
|
|
trace_flags |= old_userobj;
|
|
|
|
for_each_tracing_cpu(cpu) {
|
|
atomic_dec(&iter.tr->data[cpu]->disabled);
|
|
}
|
|
tracing_on();
|
|
}
|
|
|
|
out:
|
|
arch_spin_unlock(&ftrace_dump_lock);
|
|
local_irq_restore(flags);
|
|
}
|
|
|
|
/* By default: disable tracing after the dump */
|
|
void ftrace_dump(enum ftrace_dump_mode oops_dump_mode)
|
|
{
|
|
__ftrace_dump(true, oops_dump_mode);
|
|
}
|
|
EXPORT_SYMBOL_GPL(ftrace_dump);
|
|
|
|
__init static int tracer_alloc_buffers(void)
|
|
{
|
|
int ring_buf_size;
|
|
enum ring_buffer_flags rb_flags;
|
|
int i;
|
|
int ret = -ENOMEM;
|
|
|
|
|
|
if (!alloc_cpumask_var(&tracing_buffer_mask, GFP_KERNEL))
|
|
goto out;
|
|
|
|
if (!alloc_cpumask_var(&tracing_cpumask, GFP_KERNEL))
|
|
goto out_free_buffer_mask;
|
|
|
|
/* Only allocate trace_printk buffers if a trace_printk exists */
|
|
if (__stop___trace_bprintk_fmt != __start___trace_bprintk_fmt)
|
|
/* Must be called before global_trace.buffer is allocated */
|
|
trace_printk_init_buffers();
|
|
|
|
/* To save memory, keep the ring buffer size to its minimum */
|
|
if (ring_buffer_expanded)
|
|
ring_buf_size = trace_buf_size;
|
|
else
|
|
ring_buf_size = 1;
|
|
|
|
rb_flags = trace_flags & TRACE_ITER_OVERWRITE ? RB_FL_OVERWRITE : 0;
|
|
|
|
cpumask_copy(tracing_buffer_mask, cpu_possible_mask);
|
|
cpumask_copy(tracing_cpumask, cpu_all_mask);
|
|
|
|
/* TODO: make the number of buffers hot pluggable with CPUS */
|
|
global_trace.buffer = ring_buffer_alloc(ring_buf_size, rb_flags);
|
|
if (!global_trace.buffer) {
|
|
printk(KERN_ERR "tracer: failed to allocate ring buffer!\n");
|
|
WARN_ON(1);
|
|
goto out_free_cpumask;
|
|
}
|
|
if (global_trace.buffer_disabled)
|
|
tracing_off();
|
|
|
|
|
|
#ifdef CONFIG_TRACER_MAX_TRACE
|
|
max_tr.buffer = ring_buffer_alloc(1, rb_flags);
|
|
if (!max_tr.buffer) {
|
|
printk(KERN_ERR "tracer: failed to allocate max ring buffer!\n");
|
|
WARN_ON(1);
|
|
ring_buffer_free(global_trace.buffer);
|
|
goto out_free_cpumask;
|
|
}
|
|
#endif
|
|
|
|
/* Allocate the first page for all buffers */
|
|
for_each_tracing_cpu(i) {
|
|
global_trace.data[i] = &per_cpu(global_trace_cpu, i);
|
|
max_tr.data[i] = &per_cpu(max_tr_data, i);
|
|
}
|
|
|
|
set_buffer_entries(&global_trace,
|
|
ring_buffer_size(global_trace.buffer, 0));
|
|
#ifdef CONFIG_TRACER_MAX_TRACE
|
|
set_buffer_entries(&max_tr, 1);
|
|
#endif
|
|
|
|
trace_init_cmdlines();
|
|
init_irq_work(&trace_work_wakeup, trace_wake_up);
|
|
|
|
register_tracer(&nop_trace);
|
|
|
|
/* All seems OK, enable tracing */
|
|
tracing_disabled = 0;
|
|
|
|
atomic_notifier_chain_register(&panic_notifier_list,
|
|
&trace_panic_notifier);
|
|
|
|
register_die_notifier(&trace_die_notifier);
|
|
|
|
while (trace_boot_options) {
|
|
char *option;
|
|
|
|
option = strsep(&trace_boot_options, ",");
|
|
trace_set_options(option);
|
|
}
|
|
|
|
return 0;
|
|
|
|
out_free_cpumask:
|
|
free_cpumask_var(tracing_cpumask);
|
|
out_free_buffer_mask:
|
|
free_cpumask_var(tracing_buffer_mask);
|
|
out:
|
|
return ret;
|
|
}
|
|
|
|
__init static int clear_boot_tracer(void)
|
|
{
|
|
/*
|
|
* The default tracer at boot buffer is an init section.
|
|
* This function is called in lateinit. If we did not
|
|
* find the boot tracer, then clear it out, to prevent
|
|
* later registration from accessing the buffer that is
|
|
* about to be freed.
|
|
*/
|
|
if (!default_bootup_tracer)
|
|
return 0;
|
|
|
|
printk(KERN_INFO "ftrace bootup tracer '%s' not registered.\n",
|
|
default_bootup_tracer);
|
|
default_bootup_tracer = NULL;
|
|
|
|
return 0;
|
|
}
|
|
|
|
early_initcall(tracer_alloc_buffers);
|
|
fs_initcall(tracer_init_debugfs);
|
|
late_initcall(clear_boot_tracer);
|