OpenCloudOS-Kernel/kernel/trace/trace_eprobe.c

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tracing: Add a probe that attaches to trace events A new dynamic event is introduced: event probe. The event is attached to an existing tracepoint and uses its fields as arguments. The user can specify custom format string of the new event, select what tracepoint arguments will be printed and how to print them. An event probe is created by writing configuration string in 'dynamic_events' ftrace file: e[:[SNAME/]ENAME] SYSTEM/EVENT [FETCHARGS] - Set an event probe -:SNAME/ENAME - Delete an event probe Where: SNAME - System name, if omitted 'eprobes' is used. ENAME - Name of the new event in SNAME, if omitted the SYSTEM_EVENT is used. SYSTEM - Name of the system, where the tracepoint is defined, mandatory. EVENT - Name of the tracepoint event in SYSTEM, mandatory. FETCHARGS - Arguments: <name>=$<field>[:TYPE] - Fetch given filed of the tracepoint and print it as given TYPE with given name. Supported types are: (u8/u16/u32/u64/s8/s16/s32/s64), basic type (x8/x16/x32/x64), hexadecimal types "string", "ustring" and bitfield. Example, attach an event probe on openat system call and print name of the file that will be opened: echo "e:esys/eopen syscalls/sys_enter_openat file=\$filename:string" >> dynamic_events A new dynamic event is created in events/esys/eopen/ directory. It can be deleted with: echo "-:esys/eopen" >> dynamic_events Filters, triggers and histograms can be attached to the new event, it can be matched in synthetic events. There is one limitation - an event probe can not be attached to kprobe, uprobe or another event probe. Link: https://lkml.kernel.org/r/20210812145805.2292326-1-tz.stoyanov@gmail.com Link: https://lkml.kernel.org/r/20210819152825.142428383@goodmis.org Acked-by: Masami Hiramatsu <mhiramat@kernel.org> Co-developed-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Signed-off-by: Tzvetomir Stoyanov (VMware) <tz.stoyanov@gmail.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-08-19 23:26:06 +08:00
// SPDX-License-Identifier: GPL-2.0
/*
* event probes
*
* Part of this code was copied from kernel/trace/trace_kprobe.c written by
* Masami Hiramatsu <mhiramat@kernel.org>
*
* Copyright (C) 2021, VMware Inc, Steven Rostedt <rostedt@goodmis.org>
* Copyright (C) 2021, VMware Inc, Tzvetomir Stoyanov tz.stoyanov@gmail.com>
*
*/
#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/ftrace.h>
#include "trace_dynevent.h"
#include "trace_probe.h"
#include "trace_probe_tmpl.h"
#define EPROBE_EVENT_SYSTEM "eprobes"
struct trace_eprobe {
/* tracepoint system */
const char *event_system;
/* tracepoint event */
const char *event_name;
struct trace_event_call *event;
struct dyn_event devent;
struct trace_probe tp;
};
struct eprobe_data {
struct trace_event_file *file;
struct trace_eprobe *ep;
};
static int __trace_eprobe_create(int argc, const char *argv[]);
static void trace_event_probe_cleanup(struct trace_eprobe *ep)
{
if (!ep)
return;
trace_probe_cleanup(&ep->tp);
kfree(ep->event_name);
kfree(ep->event_system);
if (ep->event)
trace_event_put_ref(ep->event);
kfree(ep);
}
static struct trace_eprobe *to_trace_eprobe(struct dyn_event *ev)
{
return container_of(ev, struct trace_eprobe, devent);
}
static int eprobe_dyn_event_create(const char *raw_command)
{
return trace_probe_create(raw_command, __trace_eprobe_create);
}
static int eprobe_dyn_event_show(struct seq_file *m, struct dyn_event *ev)
{
struct trace_eprobe *ep = to_trace_eprobe(ev);
int i;
seq_printf(m, "e:%s/%s", trace_probe_group_name(&ep->tp),
trace_probe_name(&ep->tp));
seq_printf(m, " %s.%s", ep->event_system, ep->event_name);
for (i = 0; i < ep->tp.nr_args; i++)
seq_printf(m, " %s=%s", ep->tp.args[i].name, ep->tp.args[i].comm);
seq_putc(m, '\n');
return 0;
}
static int unregister_trace_eprobe(struct trace_eprobe *ep)
{
/* If other probes are on the event, just unregister eprobe */
if (trace_probe_has_sibling(&ep->tp))
goto unreg;
/* Enabled event can not be unregistered */
if (trace_probe_is_enabled(&ep->tp))
return -EBUSY;
/* Will fail if probe is being used by ftrace or perf */
if (trace_probe_unregister_event_call(&ep->tp))
return -EBUSY;
unreg:
dyn_event_remove(&ep->devent);
trace_probe_unlink(&ep->tp);
return 0;
}
static int eprobe_dyn_event_release(struct dyn_event *ev)
{
struct trace_eprobe *ep = to_trace_eprobe(ev);
int ret = unregister_trace_eprobe(ep);
if (!ret)
trace_event_probe_cleanup(ep);
return ret;
}
static bool eprobe_dyn_event_is_busy(struct dyn_event *ev)
{
struct trace_eprobe *ep = to_trace_eprobe(ev);
return trace_probe_is_enabled(&ep->tp);
}
static bool eprobe_dyn_event_match(const char *system, const char *event,
int argc, const char **argv, struct dyn_event *ev)
{
struct trace_eprobe *ep = to_trace_eprobe(ev);
const char *slash;
/*
* We match the following:
* event only - match all eprobes with event name
* system and event only - match all system/event probes
*
* The below has the above satisfied with more arguments:
*
* attached system/event - If the arg has the system and event
* the probe is attached to, match
* probes with the attachment.
*
* If any more args are given, then it requires a full match.
*/
/*
* If system exists, but this probe is not part of that system
* do not match.
*/
if (system && strcmp(trace_probe_group_name(&ep->tp), system) != 0)
return false;
/* Must match the event name */
if (strcmp(trace_probe_name(&ep->tp), event) != 0)
return false;
/* No arguments match all */
if (argc < 1)
return true;
/* First argument is the system/event the probe is attached to */
slash = strchr(argv[0], '/');
if (!slash)
slash = strchr(argv[0], '.');
if (!slash)
return false;
if (strncmp(ep->event_system, argv[0], slash - argv[0]))
return false;
if (strcmp(ep->event_name, slash + 1))
return false;
argc--;
argv++;
/* If there are no other args, then match */
if (argc < 1)
return true;
return trace_probe_match_command_args(&ep->tp, argc, argv);
tracing: Add a probe that attaches to trace events A new dynamic event is introduced: event probe. The event is attached to an existing tracepoint and uses its fields as arguments. The user can specify custom format string of the new event, select what tracepoint arguments will be printed and how to print them. An event probe is created by writing configuration string in 'dynamic_events' ftrace file: e[:[SNAME/]ENAME] SYSTEM/EVENT [FETCHARGS] - Set an event probe -:SNAME/ENAME - Delete an event probe Where: SNAME - System name, if omitted 'eprobes' is used. ENAME - Name of the new event in SNAME, if omitted the SYSTEM_EVENT is used. SYSTEM - Name of the system, where the tracepoint is defined, mandatory. EVENT - Name of the tracepoint event in SYSTEM, mandatory. FETCHARGS - Arguments: <name>=$<field>[:TYPE] - Fetch given filed of the tracepoint and print it as given TYPE with given name. Supported types are: (u8/u16/u32/u64/s8/s16/s32/s64), basic type (x8/x16/x32/x64), hexadecimal types "string", "ustring" and bitfield. Example, attach an event probe on openat system call and print name of the file that will be opened: echo "e:esys/eopen syscalls/sys_enter_openat file=\$filename:string" >> dynamic_events A new dynamic event is created in events/esys/eopen/ directory. It can be deleted with: echo "-:esys/eopen" >> dynamic_events Filters, triggers and histograms can be attached to the new event, it can be matched in synthetic events. There is one limitation - an event probe can not be attached to kprobe, uprobe or another event probe. Link: https://lkml.kernel.org/r/20210812145805.2292326-1-tz.stoyanov@gmail.com Link: https://lkml.kernel.org/r/20210819152825.142428383@goodmis.org Acked-by: Masami Hiramatsu <mhiramat@kernel.org> Co-developed-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Signed-off-by: Tzvetomir Stoyanov (VMware) <tz.stoyanov@gmail.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-08-19 23:26:06 +08:00
}
static struct dyn_event_operations eprobe_dyn_event_ops = {
.create = eprobe_dyn_event_create,
.show = eprobe_dyn_event_show,
.is_busy = eprobe_dyn_event_is_busy,
.free = eprobe_dyn_event_release,
.match = eprobe_dyn_event_match,
};
static struct trace_eprobe *alloc_event_probe(const char *group,
const char *this_event,
struct trace_event_call *event,
int nargs)
{
struct trace_eprobe *ep;
const char *event_name;
const char *sys_name;
int ret = -ENOMEM;
if (!event)
return ERR_PTR(-ENODEV);
sys_name = event->class->system;
event_name = trace_event_name(event);
ep = kzalloc(struct_size(ep, tp.args, nargs), GFP_KERNEL);
if (!ep) {
trace_event_put_ref(event);
tracing: Add a probe that attaches to trace events A new dynamic event is introduced: event probe. The event is attached to an existing tracepoint and uses its fields as arguments. The user can specify custom format string of the new event, select what tracepoint arguments will be printed and how to print them. An event probe is created by writing configuration string in 'dynamic_events' ftrace file: e[:[SNAME/]ENAME] SYSTEM/EVENT [FETCHARGS] - Set an event probe -:SNAME/ENAME - Delete an event probe Where: SNAME - System name, if omitted 'eprobes' is used. ENAME - Name of the new event in SNAME, if omitted the SYSTEM_EVENT is used. SYSTEM - Name of the system, where the tracepoint is defined, mandatory. EVENT - Name of the tracepoint event in SYSTEM, mandatory. FETCHARGS - Arguments: <name>=$<field>[:TYPE] - Fetch given filed of the tracepoint and print it as given TYPE with given name. Supported types are: (u8/u16/u32/u64/s8/s16/s32/s64), basic type (x8/x16/x32/x64), hexadecimal types "string", "ustring" and bitfield. Example, attach an event probe on openat system call and print name of the file that will be opened: echo "e:esys/eopen syscalls/sys_enter_openat file=\$filename:string" >> dynamic_events A new dynamic event is created in events/esys/eopen/ directory. It can be deleted with: echo "-:esys/eopen" >> dynamic_events Filters, triggers and histograms can be attached to the new event, it can be matched in synthetic events. There is one limitation - an event probe can not be attached to kprobe, uprobe or another event probe. Link: https://lkml.kernel.org/r/20210812145805.2292326-1-tz.stoyanov@gmail.com Link: https://lkml.kernel.org/r/20210819152825.142428383@goodmis.org Acked-by: Masami Hiramatsu <mhiramat@kernel.org> Co-developed-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Signed-off-by: Tzvetomir Stoyanov (VMware) <tz.stoyanov@gmail.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-08-19 23:26:06 +08:00
goto error;
}
ep->event = event;
ep->event_name = kstrdup(event_name, GFP_KERNEL);
if (!ep->event_name)
goto error;
ep->event_system = kstrdup(sys_name, GFP_KERNEL);
if (!ep->event_system)
goto error;
ret = trace_probe_init(&ep->tp, this_event, group, false);
if (ret < 0)
goto error;
dyn_event_init(&ep->devent, &eprobe_dyn_event_ops);
return ep;
error:
trace_event_probe_cleanup(ep);
return ERR_PTR(ret);
}
static int trace_eprobe_tp_arg_update(struct trace_eprobe *ep, int i)
{
struct probe_arg *parg = &ep->tp.args[i];
struct ftrace_event_field *field;
struct list_head *head;
head = trace_get_fields(ep->event);
list_for_each_entry(field, head, link) {
if (!strcmp(parg->code->data, field->name)) {
kfree(parg->code->data);
parg->code->data = field;
return 0;
}
}
kfree(parg->code->data);
parg->code->data = NULL;
return -ENOENT;
}
static int eprobe_event_define_fields(struct trace_event_call *event_call)
{
int ret;
struct eprobe_trace_entry_head field;
struct trace_probe *tp;
tp = trace_probe_primary_from_call(event_call);
if (WARN_ON_ONCE(!tp))
return -ENOENT;
DEFINE_FIELD(unsigned int, type, FIELD_STRING_TYPE, 0);
return traceprobe_define_arg_fields(event_call, sizeof(field), tp);
}
static struct trace_event_fields eprobe_fields_array[] = {
{ .type = TRACE_FUNCTION_TYPE,
.define_fields = eprobe_event_define_fields },
{}
};
/* Event entry printers */
static enum print_line_t
print_eprobe_event(struct trace_iterator *iter, int flags,
struct trace_event *event)
{
struct eprobe_trace_entry_head *field;
struct trace_event_call *pevent;
struct trace_event *probed_event;
struct trace_seq *s = &iter->seq;
struct trace_probe *tp;
field = (struct eprobe_trace_entry_head *)iter->ent;
tp = trace_probe_primary_from_call(
container_of(event, struct trace_event_call, event));
if (WARN_ON_ONCE(!tp))
goto out;
trace_seq_printf(s, "%s: (", trace_probe_name(tp));
probed_event = ftrace_find_event(field->type);
if (probed_event) {
pevent = container_of(probed_event, struct trace_event_call, event);
trace_seq_printf(s, "%s.%s", pevent->class->system,
trace_event_name(pevent));
} else {
trace_seq_printf(s, "%u", field->type);
}
trace_seq_putc(s, ')');
if (print_probe_args(s, tp->args, tp->nr_args,
(u8 *)&field[1], field) < 0)
goto out;
trace_seq_putc(s, '\n');
out:
return trace_handle_return(s);
}
static unsigned long get_event_field(struct fetch_insn *code, void *rec)
{
struct ftrace_event_field *field = code->data;
unsigned long val;
void *addr;
addr = rec + field->offset;
switch (field->size) {
case 1:
if (field->is_signed)
val = *(char *)addr;
else
val = *(unsigned char *)addr;
break;
case 2:
if (field->is_signed)
val = *(short *)addr;
else
val = *(unsigned short *)addr;
break;
case 4:
if (field->is_signed)
val = *(int *)addr;
else
val = *(unsigned int *)addr;
break;
default:
if (field->is_signed)
val = *(long *)addr;
else
val = *(unsigned long *)addr;
break;
}
return val;
}
static int get_eprobe_size(struct trace_probe *tp, void *rec)
{
struct probe_arg *arg;
int i, len, ret = 0;
for (i = 0; i < tp->nr_args; i++) {
arg = tp->args + i;
if (unlikely(arg->dynamic)) {
unsigned long val;
val = get_event_field(arg->code, rec);
len = process_fetch_insn_bottom(arg->code + 1, val, NULL, NULL);
if (len > 0)
ret += len;
}
}
return ret;
}
/* Kprobe specific fetch functions */
/* Note that we don't verify it, since the code does not come from user space */
static int
process_fetch_insn(struct fetch_insn *code, void *rec, void *dest,
void *base)
{
unsigned long val;
val = get_event_field(code, rec);
return process_fetch_insn_bottom(code + 1, val, dest, base);
}
NOKPROBE_SYMBOL(process_fetch_insn)
/* Return the length of string -- including null terminal byte */
static nokprobe_inline int
fetch_store_strlen_user(unsigned long addr)
{
const void __user *uaddr = (__force const void __user *)addr;
return strnlen_user_nofault(uaddr, MAX_STRING_SIZE);
}
/* Return the length of string -- including null terminal byte */
static nokprobe_inline int
fetch_store_strlen(unsigned long addr)
{
int ret, len = 0;
u8 c;
#ifdef CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
if (addr < TASK_SIZE)
return fetch_store_strlen_user(addr);
#endif
do {
ret = copy_from_kernel_nofault(&c, (u8 *)addr + len, 1);
len++;
} while (c && ret == 0 && len < MAX_STRING_SIZE);
return (ret < 0) ? ret : len;
}
/*
* Fetch a null-terminated string from user. Caller MUST set *(u32 *)buf
* with max length and relative data location.
*/
static nokprobe_inline int
fetch_store_string_user(unsigned long addr, void *dest, void *base)
{
const void __user *uaddr = (__force const void __user *)addr;
int maxlen = get_loc_len(*(u32 *)dest);
void *__dest;
long ret;
if (unlikely(!maxlen))
return -ENOMEM;
__dest = get_loc_data(dest, base);
ret = strncpy_from_user_nofault(__dest, uaddr, maxlen);
if (ret >= 0)
*(u32 *)dest = make_data_loc(ret, __dest - base);
return ret;
}
/*
* Fetch a null-terminated string. Caller MUST set *(u32 *)buf with max
* length and relative data location.
*/
static nokprobe_inline int
fetch_store_string(unsigned long addr, void *dest, void *base)
{
int maxlen = get_loc_len(*(u32 *)dest);
void *__dest;
long ret;
#ifdef CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
if ((unsigned long)addr < TASK_SIZE)
return fetch_store_string_user(addr, dest, base);
#endif
if (unlikely(!maxlen))
return -ENOMEM;
__dest = get_loc_data(dest, base);
/*
* Try to get string again, since the string can be changed while
* probing.
*/
ret = strncpy_from_kernel_nofault(__dest, (void *)addr, maxlen);
if (ret >= 0)
*(u32 *)dest = make_data_loc(ret, __dest - base);
return ret;
}
static nokprobe_inline int
probe_mem_read_user(void *dest, void *src, size_t size)
{
const void __user *uaddr = (__force const void __user *)src;
return copy_from_user_nofault(dest, uaddr, size);
}
static nokprobe_inline int
probe_mem_read(void *dest, void *src, size_t size)
{
#ifdef CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
if ((unsigned long)src < TASK_SIZE)
return probe_mem_read_user(dest, src, size);
#endif
return copy_from_kernel_nofault(dest, src, size);
}
/* eprobe handler */
static inline void
__eprobe_trace_func(struct eprobe_data *edata, void *rec)
{
struct eprobe_trace_entry_head *entry;
struct trace_event_call *call = trace_probe_event_call(&edata->ep->tp);
struct trace_event_buffer fbuffer;
int dsize;
if (WARN_ON_ONCE(call != edata->file->event_call))
return;
if (trace_trigger_soft_disabled(edata->file))
return;
dsize = get_eprobe_size(&edata->ep->tp, rec);
entry = trace_event_buffer_reserve(&fbuffer, edata->file,
sizeof(*entry) + edata->ep->tp.size + dsize);
if (!entry)
tracing: Add a probe that attaches to trace events A new dynamic event is introduced: event probe. The event is attached to an existing tracepoint and uses its fields as arguments. The user can specify custom format string of the new event, select what tracepoint arguments will be printed and how to print them. An event probe is created by writing configuration string in 'dynamic_events' ftrace file: e[:[SNAME/]ENAME] SYSTEM/EVENT [FETCHARGS] - Set an event probe -:SNAME/ENAME - Delete an event probe Where: SNAME - System name, if omitted 'eprobes' is used. ENAME - Name of the new event in SNAME, if omitted the SYSTEM_EVENT is used. SYSTEM - Name of the system, where the tracepoint is defined, mandatory. EVENT - Name of the tracepoint event in SYSTEM, mandatory. FETCHARGS - Arguments: <name>=$<field>[:TYPE] - Fetch given filed of the tracepoint and print it as given TYPE with given name. Supported types are: (u8/u16/u32/u64/s8/s16/s32/s64), basic type (x8/x16/x32/x64), hexadecimal types "string", "ustring" and bitfield. Example, attach an event probe on openat system call and print name of the file that will be opened: echo "e:esys/eopen syscalls/sys_enter_openat file=\$filename:string" >> dynamic_events A new dynamic event is created in events/esys/eopen/ directory. It can be deleted with: echo "-:esys/eopen" >> dynamic_events Filters, triggers and histograms can be attached to the new event, it can be matched in synthetic events. There is one limitation - an event probe can not be attached to kprobe, uprobe or another event probe. Link: https://lkml.kernel.org/r/20210812145805.2292326-1-tz.stoyanov@gmail.com Link: https://lkml.kernel.org/r/20210819152825.142428383@goodmis.org Acked-by: Masami Hiramatsu <mhiramat@kernel.org> Co-developed-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Signed-off-by: Tzvetomir Stoyanov (VMware) <tz.stoyanov@gmail.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-08-19 23:26:06 +08:00
return;
entry = fbuffer.entry = ring_buffer_event_data(fbuffer.event);
if (edata->ep->event)
entry->type = edata->ep->event->event.type;
else
entry->type = 0;
store_trace_args(&entry[1], &edata->ep->tp, rec, sizeof(*entry), dsize);
trace_event_buffer_commit(&fbuffer);
}
/*
* The event probe implementation uses event triggers to get access to
* the event it is attached to, but is not an actual trigger. The below
* functions are just stubs to fulfill what is needed to use the trigger
* infrastructure.
*/
static int eprobe_trigger_init(struct event_trigger_ops *ops,
struct event_trigger_data *data)
{
return 0;
}
static void eprobe_trigger_free(struct event_trigger_ops *ops,
struct event_trigger_data *data)
{
}
static int eprobe_trigger_print(struct seq_file *m,
struct event_trigger_ops *ops,
struct event_trigger_data *data)
{
/* Do not print eprobe event triggers */
return 0;
}
static void eprobe_trigger_func(struct event_trigger_data *data,
struct trace_buffer *buffer, void *rec,
struct ring_buffer_event *rbe)
{
struct eprobe_data *edata = data->private_data;
__eprobe_trace_func(edata, rec);
}
static struct event_trigger_ops eprobe_trigger_ops = {
.trigger = eprobe_trigger_func,
tracing: Add a probe that attaches to trace events A new dynamic event is introduced: event probe. The event is attached to an existing tracepoint and uses its fields as arguments. The user can specify custom format string of the new event, select what tracepoint arguments will be printed and how to print them. An event probe is created by writing configuration string in 'dynamic_events' ftrace file: e[:[SNAME/]ENAME] SYSTEM/EVENT [FETCHARGS] - Set an event probe -:SNAME/ENAME - Delete an event probe Where: SNAME - System name, if omitted 'eprobes' is used. ENAME - Name of the new event in SNAME, if omitted the SYSTEM_EVENT is used. SYSTEM - Name of the system, where the tracepoint is defined, mandatory. EVENT - Name of the tracepoint event in SYSTEM, mandatory. FETCHARGS - Arguments: <name>=$<field>[:TYPE] - Fetch given filed of the tracepoint and print it as given TYPE with given name. Supported types are: (u8/u16/u32/u64/s8/s16/s32/s64), basic type (x8/x16/x32/x64), hexadecimal types "string", "ustring" and bitfield. Example, attach an event probe on openat system call and print name of the file that will be opened: echo "e:esys/eopen syscalls/sys_enter_openat file=\$filename:string" >> dynamic_events A new dynamic event is created in events/esys/eopen/ directory. It can be deleted with: echo "-:esys/eopen" >> dynamic_events Filters, triggers and histograms can be attached to the new event, it can be matched in synthetic events. There is one limitation - an event probe can not be attached to kprobe, uprobe or another event probe. Link: https://lkml.kernel.org/r/20210812145805.2292326-1-tz.stoyanov@gmail.com Link: https://lkml.kernel.org/r/20210819152825.142428383@goodmis.org Acked-by: Masami Hiramatsu <mhiramat@kernel.org> Co-developed-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Signed-off-by: Tzvetomir Stoyanov (VMware) <tz.stoyanov@gmail.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-08-19 23:26:06 +08:00
.print = eprobe_trigger_print,
.init = eprobe_trigger_init,
.free = eprobe_trigger_free,
};
static int eprobe_trigger_cmd_parse(struct event_command *cmd_ops,
struct trace_event_file *file,
char *glob, char *cmd, char *param)
tracing: Add a probe that attaches to trace events A new dynamic event is introduced: event probe. The event is attached to an existing tracepoint and uses its fields as arguments. The user can specify custom format string of the new event, select what tracepoint arguments will be printed and how to print them. An event probe is created by writing configuration string in 'dynamic_events' ftrace file: e[:[SNAME/]ENAME] SYSTEM/EVENT [FETCHARGS] - Set an event probe -:SNAME/ENAME - Delete an event probe Where: SNAME - System name, if omitted 'eprobes' is used. ENAME - Name of the new event in SNAME, if omitted the SYSTEM_EVENT is used. SYSTEM - Name of the system, where the tracepoint is defined, mandatory. EVENT - Name of the tracepoint event in SYSTEM, mandatory. FETCHARGS - Arguments: <name>=$<field>[:TYPE] - Fetch given filed of the tracepoint and print it as given TYPE with given name. Supported types are: (u8/u16/u32/u64/s8/s16/s32/s64), basic type (x8/x16/x32/x64), hexadecimal types "string", "ustring" and bitfield. Example, attach an event probe on openat system call and print name of the file that will be opened: echo "e:esys/eopen syscalls/sys_enter_openat file=\$filename:string" >> dynamic_events A new dynamic event is created in events/esys/eopen/ directory. It can be deleted with: echo "-:esys/eopen" >> dynamic_events Filters, triggers and histograms can be attached to the new event, it can be matched in synthetic events. There is one limitation - an event probe can not be attached to kprobe, uprobe or another event probe. Link: https://lkml.kernel.org/r/20210812145805.2292326-1-tz.stoyanov@gmail.com Link: https://lkml.kernel.org/r/20210819152825.142428383@goodmis.org Acked-by: Masami Hiramatsu <mhiramat@kernel.org> Co-developed-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Signed-off-by: Tzvetomir Stoyanov (VMware) <tz.stoyanov@gmail.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-08-19 23:26:06 +08:00
{
return -1;
}
static int eprobe_trigger_reg_func(char *glob,
struct event_trigger_data *data,
struct trace_event_file *file)
tracing: Add a probe that attaches to trace events A new dynamic event is introduced: event probe. The event is attached to an existing tracepoint and uses its fields as arguments. The user can specify custom format string of the new event, select what tracepoint arguments will be printed and how to print them. An event probe is created by writing configuration string in 'dynamic_events' ftrace file: e[:[SNAME/]ENAME] SYSTEM/EVENT [FETCHARGS] - Set an event probe -:SNAME/ENAME - Delete an event probe Where: SNAME - System name, if omitted 'eprobes' is used. ENAME - Name of the new event in SNAME, if omitted the SYSTEM_EVENT is used. SYSTEM - Name of the system, where the tracepoint is defined, mandatory. EVENT - Name of the tracepoint event in SYSTEM, mandatory. FETCHARGS - Arguments: <name>=$<field>[:TYPE] - Fetch given filed of the tracepoint and print it as given TYPE with given name. Supported types are: (u8/u16/u32/u64/s8/s16/s32/s64), basic type (x8/x16/x32/x64), hexadecimal types "string", "ustring" and bitfield. Example, attach an event probe on openat system call and print name of the file that will be opened: echo "e:esys/eopen syscalls/sys_enter_openat file=\$filename:string" >> dynamic_events A new dynamic event is created in events/esys/eopen/ directory. It can be deleted with: echo "-:esys/eopen" >> dynamic_events Filters, triggers and histograms can be attached to the new event, it can be matched in synthetic events. There is one limitation - an event probe can not be attached to kprobe, uprobe or another event probe. Link: https://lkml.kernel.org/r/20210812145805.2292326-1-tz.stoyanov@gmail.com Link: https://lkml.kernel.org/r/20210819152825.142428383@goodmis.org Acked-by: Masami Hiramatsu <mhiramat@kernel.org> Co-developed-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Signed-off-by: Tzvetomir Stoyanov (VMware) <tz.stoyanov@gmail.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-08-19 23:26:06 +08:00
{
return -1;
}
static void eprobe_trigger_unreg_func(char *glob,
struct event_trigger_data *data,
struct trace_event_file *file)
tracing: Add a probe that attaches to trace events A new dynamic event is introduced: event probe. The event is attached to an existing tracepoint and uses its fields as arguments. The user can specify custom format string of the new event, select what tracepoint arguments will be printed and how to print them. An event probe is created by writing configuration string in 'dynamic_events' ftrace file: e[:[SNAME/]ENAME] SYSTEM/EVENT [FETCHARGS] - Set an event probe -:SNAME/ENAME - Delete an event probe Where: SNAME - System name, if omitted 'eprobes' is used. ENAME - Name of the new event in SNAME, if omitted the SYSTEM_EVENT is used. SYSTEM - Name of the system, where the tracepoint is defined, mandatory. EVENT - Name of the tracepoint event in SYSTEM, mandatory. FETCHARGS - Arguments: <name>=$<field>[:TYPE] - Fetch given filed of the tracepoint and print it as given TYPE with given name. Supported types are: (u8/u16/u32/u64/s8/s16/s32/s64), basic type (x8/x16/x32/x64), hexadecimal types "string", "ustring" and bitfield. Example, attach an event probe on openat system call and print name of the file that will be opened: echo "e:esys/eopen syscalls/sys_enter_openat file=\$filename:string" >> dynamic_events A new dynamic event is created in events/esys/eopen/ directory. It can be deleted with: echo "-:esys/eopen" >> dynamic_events Filters, triggers and histograms can be attached to the new event, it can be matched in synthetic events. There is one limitation - an event probe can not be attached to kprobe, uprobe or another event probe. Link: https://lkml.kernel.org/r/20210812145805.2292326-1-tz.stoyanov@gmail.com Link: https://lkml.kernel.org/r/20210819152825.142428383@goodmis.org Acked-by: Masami Hiramatsu <mhiramat@kernel.org> Co-developed-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Signed-off-by: Tzvetomir Stoyanov (VMware) <tz.stoyanov@gmail.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-08-19 23:26:06 +08:00
{
}
static struct event_trigger_ops *eprobe_trigger_get_ops(char *cmd,
char *param)
{
return &eprobe_trigger_ops;
}
static struct event_command event_trigger_cmd = {
.name = "eprobe",
.trigger_type = ETT_EVENT_EPROBE,
.flags = EVENT_CMD_FL_NEEDS_REC,
.parse = eprobe_trigger_cmd_parse,
tracing: Add a probe that attaches to trace events A new dynamic event is introduced: event probe. The event is attached to an existing tracepoint and uses its fields as arguments. The user can specify custom format string of the new event, select what tracepoint arguments will be printed and how to print them. An event probe is created by writing configuration string in 'dynamic_events' ftrace file: e[:[SNAME/]ENAME] SYSTEM/EVENT [FETCHARGS] - Set an event probe -:SNAME/ENAME - Delete an event probe Where: SNAME - System name, if omitted 'eprobes' is used. ENAME - Name of the new event in SNAME, if omitted the SYSTEM_EVENT is used. SYSTEM - Name of the system, where the tracepoint is defined, mandatory. EVENT - Name of the tracepoint event in SYSTEM, mandatory. FETCHARGS - Arguments: <name>=$<field>[:TYPE] - Fetch given filed of the tracepoint and print it as given TYPE with given name. Supported types are: (u8/u16/u32/u64/s8/s16/s32/s64), basic type (x8/x16/x32/x64), hexadecimal types "string", "ustring" and bitfield. Example, attach an event probe on openat system call and print name of the file that will be opened: echo "e:esys/eopen syscalls/sys_enter_openat file=\$filename:string" >> dynamic_events A new dynamic event is created in events/esys/eopen/ directory. It can be deleted with: echo "-:esys/eopen" >> dynamic_events Filters, triggers and histograms can be attached to the new event, it can be matched in synthetic events. There is one limitation - an event probe can not be attached to kprobe, uprobe or another event probe. Link: https://lkml.kernel.org/r/20210812145805.2292326-1-tz.stoyanov@gmail.com Link: https://lkml.kernel.org/r/20210819152825.142428383@goodmis.org Acked-by: Masami Hiramatsu <mhiramat@kernel.org> Co-developed-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Signed-off-by: Tzvetomir Stoyanov (VMware) <tz.stoyanov@gmail.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-08-19 23:26:06 +08:00
.reg = eprobe_trigger_reg_func,
.unreg = eprobe_trigger_unreg_func,
.unreg_all = NULL,
.get_trigger_ops = eprobe_trigger_get_ops,
.set_filter = NULL,
};
static struct event_trigger_data *
new_eprobe_trigger(struct trace_eprobe *ep, struct trace_event_file *file)
{
struct event_trigger_data *trigger;
struct eprobe_data *edata;
edata = kzalloc(sizeof(*edata), GFP_KERNEL);
trigger = kzalloc(sizeof(*trigger), GFP_KERNEL);
if (!trigger || !edata) {
kfree(edata);
kfree(trigger);
return ERR_PTR(-ENOMEM);
}
trigger->flags = EVENT_TRIGGER_FL_PROBE;
trigger->count = -1;
trigger->ops = &eprobe_trigger_ops;
/*
* EVENT PROBE triggers are not registered as commands with
* register_event_command(), as they are not controlled by the user
* from the trigger file
*/
trigger->cmd_ops = &event_trigger_cmd;
INIT_LIST_HEAD(&trigger->list);
RCU_INIT_POINTER(trigger->filter, NULL);
edata->file = file;
edata->ep = ep;
trigger->private_data = edata;
return trigger;
}
static int enable_eprobe(struct trace_eprobe *ep,
struct trace_event_file *eprobe_file)
{
struct event_trigger_data *trigger;
struct trace_event_file *file;
struct trace_array *tr = eprobe_file->tr;
file = find_event_file(tr, ep->event_system, ep->event_name);
if (!file)
return -ENOENT;
trigger = new_eprobe_trigger(ep, eprobe_file);
if (IS_ERR(trigger))
return PTR_ERR(trigger);
list_add_tail_rcu(&trigger->list, &file->triggers);
trace_event_trigger_enable_disable(file, 1);
update_cond_flag(file);
return 0;
}
static struct trace_event_functions eprobe_funcs = {
.trace = print_eprobe_event
};
static int disable_eprobe(struct trace_eprobe *ep,
struct trace_array *tr)
{
struct event_trigger_data *trigger;
struct trace_event_file *file;
struct eprobe_data *edata;
file = find_event_file(tr, ep->event_system, ep->event_name);
if (!file)
return -ENOENT;
list_for_each_entry(trigger, &file->triggers, list) {
if (!(trigger->flags & EVENT_TRIGGER_FL_PROBE))
continue;
edata = trigger->private_data;
if (edata->ep == ep)
break;
}
if (list_entry_is_head(trigger, &file->triggers, list))
return -ENODEV;
list_del_rcu(&trigger->list);
trace_event_trigger_enable_disable(file, 0);
update_cond_flag(file);
tracing: Fix memory leak in eprobe_register() kmemleak report: unreferenced object 0xffff900a70ec7ec0 (size 32): comm "ftracetest", pid 2770, jiffies 4295042510 (age 311.464s) hex dump (first 32 bytes): c8 31 23 45 0a 90 ff ff 40 85 c7 6e 0a 90 ff ff .1#E....@..n.... 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ backtrace: [<000000009d3751fd>] kmem_cache_alloc_trace+0x2a2/0x440 [<0000000088b8124b>] eprobe_register+0x1e3/0x350 [<000000002a9a0517>] __ftrace_event_enable_disable+0x7c/0x240 [<0000000019109321>] event_enable_write+0x93/0xe0 [<000000007d85b320>] vfs_write+0xb9/0x260 [<00000000b94c5e41>] ksys_write+0x67/0xe0 [<000000005a08c81d>] __x64_sys_write+0x1a/0x20 [<00000000240bf576>] do_syscall_64+0x3b/0xc0 [<0000000043d5d9f6>] entry_SYSCALL_64_after_hwframe+0x44/0xae unreferenced object 0xffff900a56bbf280 (size 128): comm "ftracetest", pid 2770, jiffies 4295042510 (age 311.464s) hex dump (first 32 bytes): ff ff ff ff ff ff ff ff 00 00 00 00 01 00 00 00 ................ 80 69 3b b2 ff ff ff ff 20 69 3b b2 ff ff ff ff .i;..... i;..... backtrace: [<000000009d3751fd>] kmem_cache_alloc_trace+0x2a2/0x440 [<00000000c4e90fad>] eprobe_register+0x1fc/0x350 [<000000002a9a0517>] __ftrace_event_enable_disable+0x7c/0x240 [<0000000019109321>] event_enable_write+0x93/0xe0 [<000000007d85b320>] vfs_write+0xb9/0x260 [<00000000b94c5e41>] ksys_write+0x67/0xe0 [<000000005a08c81d>] __x64_sys_write+0x1a/0x20 [<00000000240bf576>] do_syscall_64+0x3b/0xc0 [<0000000043d5d9f6>] entry_SYSCALL_64_after_hwframe+0x44/0xae In new_eprobe_trigger(), allocated edata and trigger variables are never freed. To fix, free memory in disable_eprobe(). Link: https://lkml.kernel.org/r/20211008071802.GA2098@cosmos Fixes: 7491e2c442781 ("tracing: Add a probe that attaches to trace events") Signed-off-by: Vamshi K Sthambamkadi <vamshi.k.sthambamkadi@gmail.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-10-08 15:18:06 +08:00
/* Make sure nothing is using the edata or trigger */
tracepoint_synchronize_unregister();
kfree(edata);
kfree(trigger);
tracing: Add a probe that attaches to trace events A new dynamic event is introduced: event probe. The event is attached to an existing tracepoint and uses its fields as arguments. The user can specify custom format string of the new event, select what tracepoint arguments will be printed and how to print them. An event probe is created by writing configuration string in 'dynamic_events' ftrace file: e[:[SNAME/]ENAME] SYSTEM/EVENT [FETCHARGS] - Set an event probe -:SNAME/ENAME - Delete an event probe Where: SNAME - System name, if omitted 'eprobes' is used. ENAME - Name of the new event in SNAME, if omitted the SYSTEM_EVENT is used. SYSTEM - Name of the system, where the tracepoint is defined, mandatory. EVENT - Name of the tracepoint event in SYSTEM, mandatory. FETCHARGS - Arguments: <name>=$<field>[:TYPE] - Fetch given filed of the tracepoint and print it as given TYPE with given name. Supported types are: (u8/u16/u32/u64/s8/s16/s32/s64), basic type (x8/x16/x32/x64), hexadecimal types "string", "ustring" and bitfield. Example, attach an event probe on openat system call and print name of the file that will be opened: echo "e:esys/eopen syscalls/sys_enter_openat file=\$filename:string" >> dynamic_events A new dynamic event is created in events/esys/eopen/ directory. It can be deleted with: echo "-:esys/eopen" >> dynamic_events Filters, triggers and histograms can be attached to the new event, it can be matched in synthetic events. There is one limitation - an event probe can not be attached to kprobe, uprobe or another event probe. Link: https://lkml.kernel.org/r/20210812145805.2292326-1-tz.stoyanov@gmail.com Link: https://lkml.kernel.org/r/20210819152825.142428383@goodmis.org Acked-by: Masami Hiramatsu <mhiramat@kernel.org> Co-developed-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Signed-off-by: Tzvetomir Stoyanov (VMware) <tz.stoyanov@gmail.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-08-19 23:26:06 +08:00
return 0;
}
static int enable_trace_eprobe(struct trace_event_call *call,
struct trace_event_file *file)
{
struct trace_probe *pos, *tp;
struct trace_eprobe *ep;
bool enabled;
int ret = 0;
tp = trace_probe_primary_from_call(call);
if (WARN_ON_ONCE(!tp))
return -ENODEV;
enabled = trace_probe_is_enabled(tp);
/* This also changes "enabled" state */
if (file) {
ret = trace_probe_add_file(tp, file);
if (ret)
return ret;
} else
trace_probe_set_flag(tp, TP_FLAG_PROFILE);
if (enabled)
return 0;
list_for_each_entry(pos, trace_probe_probe_list(tp), list) {
ep = container_of(pos, struct trace_eprobe, tp);
ret = enable_eprobe(ep, file);
if (ret)
break;
enabled = true;
}
if (ret) {
/* Failed to enable one of them. Roll back all */
if (enabled)
disable_eprobe(ep, file->tr);
if (file)
trace_probe_remove_file(tp, file);
else
trace_probe_clear_flag(tp, TP_FLAG_PROFILE);
}
return ret;
}
static int disable_trace_eprobe(struct trace_event_call *call,
struct trace_event_file *file)
{
struct trace_probe *pos, *tp;
struct trace_eprobe *ep;
tp = trace_probe_primary_from_call(call);
if (WARN_ON_ONCE(!tp))
return -ENODEV;
if (file) {
if (!trace_probe_get_file_link(tp, file))
return -ENOENT;
if (!trace_probe_has_single_file(tp))
goto out;
trace_probe_clear_flag(tp, TP_FLAG_TRACE);
} else
trace_probe_clear_flag(tp, TP_FLAG_PROFILE);
if (!trace_probe_is_enabled(tp)) {
list_for_each_entry(pos, trace_probe_probe_list(tp), list) {
ep = container_of(pos, struct trace_eprobe, tp);
disable_eprobe(ep, file->tr);
}
}
out:
if (file)
/*
* Synchronization is done in below function. For perf event,
* file == NULL and perf_trace_event_unreg() calls
* tracepoint_synchronize_unregister() to ensure synchronize
* event. We don't need to care about it.
*/
trace_probe_remove_file(tp, file);
return 0;
}
static int eprobe_register(struct trace_event_call *event,
enum trace_reg type, void *data)
{
struct trace_event_file *file = data;
switch (type) {
case TRACE_REG_REGISTER:
return enable_trace_eprobe(event, file);
case TRACE_REG_UNREGISTER:
return disable_trace_eprobe(event, file);
#ifdef CONFIG_PERF_EVENTS
case TRACE_REG_PERF_REGISTER:
case TRACE_REG_PERF_UNREGISTER:
case TRACE_REG_PERF_OPEN:
case TRACE_REG_PERF_CLOSE:
case TRACE_REG_PERF_ADD:
case TRACE_REG_PERF_DEL:
return 0;
#endif
}
return 0;
}
static inline void init_trace_eprobe_call(struct trace_eprobe *ep)
{
struct trace_event_call *call = trace_probe_event_call(&ep->tp);
call->flags = TRACE_EVENT_FL_EPROBE;
call->event.funcs = &eprobe_funcs;
call->class->fields_array = eprobe_fields_array;
call->class->reg = eprobe_register;
}
static struct trace_event_call *
find_and_get_event(const char *system, const char *event_name)
{
struct trace_event_call *tp_event;
const char *name;
list_for_each_entry(tp_event, &ftrace_events, list) {
/* Skip other probes and ftrace events */
if (tp_event->flags &
(TRACE_EVENT_FL_IGNORE_ENABLE |
TRACE_EVENT_FL_KPROBE |
TRACE_EVENT_FL_UPROBE |
TRACE_EVENT_FL_EPROBE))
continue;
if (!tp_event->class->system ||
strcmp(system, tp_event->class->system))
continue;
name = trace_event_name(tp_event);
if (!name || strcmp(event_name, name))
continue;
if (!trace_event_try_get_ref(tp_event)) {
return NULL;
break;
}
return tp_event;
break;
}
return NULL;
}
static int trace_eprobe_tp_update_arg(struct trace_eprobe *ep, const char *argv[], int i)
{
unsigned int flags = TPARG_FL_KERNEL | TPARG_FL_TPOINT;
int ret;
ret = traceprobe_parse_probe_arg(&ep->tp, i, argv[i], flags);
if (ret)
return ret;
if (ep->tp.args[i].code->op == FETCH_OP_TP_ARG)
ret = trace_eprobe_tp_arg_update(ep, i);
return ret;
}
static int __trace_eprobe_create(int argc, const char *argv[])
{
/*
* Argument syntax:
* e[:[GRP/]ENAME] SYSTEM.EVENT [FETCHARGS]
* Fetch args:
* <name>=$<field>[:TYPE]
*/
const char *event = NULL, *group = EPROBE_EVENT_SYSTEM;
const char *sys_event = NULL, *sys_name = NULL;
struct trace_event_call *event_call;
struct trace_eprobe *ep = NULL;
char buf1[MAX_EVENT_NAME_LEN];
char buf2[MAX_EVENT_NAME_LEN];
int ret = 0;
int i;
if (argc < 2 || argv[0][0] != 'e')
return -ECANCELED;
trace_probe_log_init("event_probe", argc, argv);
event = strchr(&argv[0][1], ':');
if (event) {
event++;
ret = traceprobe_parse_event_name(&event, &group, buf1,
event - argv[0]);
if (ret)
goto parse_error;
} else {
strscpy(buf1, argv[1], MAX_EVENT_NAME_LEN);
sanitize_event_name(buf1);
event = buf1;
}
if (!is_good_name(event) || !is_good_name(group))
goto parse_error;
sys_event = argv[1];
ret = traceprobe_parse_event_name(&sys_event, &sys_name, buf2,
sys_event - argv[1]);
if (ret || !sys_name)
goto parse_error;
if (!is_good_name(sys_event) || !is_good_name(sys_name))
goto parse_error;
mutex_lock(&event_mutex);
event_call = find_and_get_event(sys_name, sys_event);
ep = alloc_event_probe(group, event, event_call, argc - 2);
mutex_unlock(&event_mutex);
if (IS_ERR(ep)) {
ret = PTR_ERR(ep);
/* This must return -ENOMEM or missing event, else there is a bug */
WARN_ON_ONCE(ret != -ENOMEM && ret != -ENODEV);
ep = NULL;
goto error;
tracing: Add a probe that attaches to trace events A new dynamic event is introduced: event probe. The event is attached to an existing tracepoint and uses its fields as arguments. The user can specify custom format string of the new event, select what tracepoint arguments will be printed and how to print them. An event probe is created by writing configuration string in 'dynamic_events' ftrace file: e[:[SNAME/]ENAME] SYSTEM/EVENT [FETCHARGS] - Set an event probe -:SNAME/ENAME - Delete an event probe Where: SNAME - System name, if omitted 'eprobes' is used. ENAME - Name of the new event in SNAME, if omitted the SYSTEM_EVENT is used. SYSTEM - Name of the system, where the tracepoint is defined, mandatory. EVENT - Name of the tracepoint event in SYSTEM, mandatory. FETCHARGS - Arguments: <name>=$<field>[:TYPE] - Fetch given filed of the tracepoint and print it as given TYPE with given name. Supported types are: (u8/u16/u32/u64/s8/s16/s32/s64), basic type (x8/x16/x32/x64), hexadecimal types "string", "ustring" and bitfield. Example, attach an event probe on openat system call and print name of the file that will be opened: echo "e:esys/eopen syscalls/sys_enter_openat file=\$filename:string" >> dynamic_events A new dynamic event is created in events/esys/eopen/ directory. It can be deleted with: echo "-:esys/eopen" >> dynamic_events Filters, triggers and histograms can be attached to the new event, it can be matched in synthetic events. There is one limitation - an event probe can not be attached to kprobe, uprobe or another event probe. Link: https://lkml.kernel.org/r/20210812145805.2292326-1-tz.stoyanov@gmail.com Link: https://lkml.kernel.org/r/20210819152825.142428383@goodmis.org Acked-by: Masami Hiramatsu <mhiramat@kernel.org> Co-developed-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Signed-off-by: Tzvetomir Stoyanov (VMware) <tz.stoyanov@gmail.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-08-19 23:26:06 +08:00
}
argc -= 2; argv += 2;
/* parse arguments */
for (i = 0; i < argc && i < MAX_TRACE_ARGS; i++) {
trace_probe_log_set_index(i + 2);
ret = trace_eprobe_tp_update_arg(ep, argv, i);
if (ret)
goto error;
}
ret = traceprobe_set_print_fmt(&ep->tp, PROBE_PRINT_EVENT);
if (ret < 0)
goto error;
init_trace_eprobe_call(ep);
mutex_lock(&event_mutex);
ret = trace_probe_register_event_call(&ep->tp);
if (ret) {
if (ret == -EEXIST) {
trace_probe_log_set_index(0);
trace_probe_log_err(0, EVENT_EXIST);
}
mutex_unlock(&event_mutex);
goto error;
}
ret = dyn_event_add(&ep->devent, &ep->tp.event->call);
mutex_unlock(&event_mutex);
return ret;
parse_error:
ret = -EINVAL;
error:
trace_event_probe_cleanup(ep);
return ret;
}
/*
* Register dynevent at core_initcall. This allows kernel to setup eprobe
* events in postcore_initcall without tracefs.
*/
static __init int trace_events_eprobe_init_early(void)
{
int err = 0;
err = dyn_event_register(&eprobe_dyn_event_ops);
if (err)
pr_warn("Could not register eprobe_dyn_event_ops\n");
return err;
}
core_initcall(trace_events_eprobe_init_early);