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OpenCloudOS-Kernel/kernel/trace/trace_uprobe.c

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/*
* uprobes-based tracing events
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*
* Copyright (C) IBM Corporation, 2010-2012
* Author: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
*/
#include <linux/module.h>
#include <linux/uaccess.h>
#include <linux/uprobes.h>
#include <linux/namei.h>
#include <linux/string.h>
#include "trace_probe.h"
#define UPROBE_EVENT_SYSTEM "uprobes"
struct uprobe_trace_entry_head {
struct trace_entry ent;
unsigned long vaddr[];
};
#define SIZEOF_TRACE_ENTRY(is_return) \
(sizeof(struct uprobe_trace_entry_head) + \
sizeof(unsigned long) * (is_return ? 2 : 1))
#define DATAOF_TRACE_ENTRY(entry, is_return) \
((void*)(entry) + SIZEOF_TRACE_ENTRY(is_return))
struct trace_uprobe_filter {
rwlock_t rwlock;
int nr_systemwide;
struct list_head perf_events;
};
/*
* uprobe event core functions
*/
struct trace_uprobe {
struct list_head list;
struct trace_uprobe_filter filter;
struct uprobe_consumer consumer;
struct inode *inode;
char *filename;
unsigned long offset;
unsigned long nhit;
struct trace_probe tp;
};
#define SIZEOF_TRACE_UPROBE(n) \
(offsetof(struct trace_uprobe, tp.args) + \
(sizeof(struct probe_arg) * (n)))
static int register_uprobe_event(struct trace_uprobe *tu);
static int unregister_uprobe_event(struct trace_uprobe *tu);
static DEFINE_MUTEX(uprobe_lock);
static LIST_HEAD(uprobe_list);
static int uprobe_dispatcher(struct uprobe_consumer *con, struct pt_regs *regs);
static int uretprobe_dispatcher(struct uprobe_consumer *con,
unsigned long func, struct pt_regs *regs);
#ifdef CONFIG_STACK_GROWSUP
static unsigned long adjust_stack_addr(unsigned long addr, unsigned int n)
{
return addr - (n * sizeof(long));
}
#else
static unsigned long adjust_stack_addr(unsigned long addr, unsigned int n)
{
return addr + (n * sizeof(long));
}
#endif
static unsigned long get_user_stack_nth(struct pt_regs *regs, unsigned int n)
{
unsigned long ret;
unsigned long addr = user_stack_pointer(regs);
addr = adjust_stack_addr(addr, n);
if (copy_from_user(&ret, (void __force __user *) addr, sizeof(ret)))
return 0;
return ret;
}
/*
* Uprobes-specific fetch functions
*/
#define DEFINE_FETCH_stack(type) \
static __kprobes void FETCH_FUNC_NAME(stack, type)(struct pt_regs *regs,\
void *offset, void *dest) \
{ \
*(type *)dest = (type)get_user_stack_nth(regs, \
((unsigned long)offset)); \
}
DEFINE_BASIC_FETCH_FUNCS(stack)
/* No string on the stack entry */
#define fetch_stack_string NULL
#define fetch_stack_string_size NULL
#define DEFINE_FETCH_memory(type) \
static __kprobes void FETCH_FUNC_NAME(memory, type)(struct pt_regs *regs,\
void *addr, void *dest) \
{ \
type retval; \
void __user *vaddr = (void __force __user *) addr; \
\
if (copy_from_user(&retval, vaddr, sizeof(type))) \
*(type *)dest = 0; \
else \
*(type *) dest = retval; \
}
DEFINE_BASIC_FETCH_FUNCS(memory)
/*
* Fetch a null-terminated string. Caller MUST set *(u32 *)dest with max
* length and relative data location.
*/
static __kprobes void FETCH_FUNC_NAME(memory, string)(struct pt_regs *regs,
void *addr, void *dest)
{
long ret;
u32 rloc = *(u32 *)dest;
int maxlen = get_rloc_len(rloc);
u8 *dst = get_rloc_data(dest);
void __user *src = (void __force __user *) addr;
if (!maxlen)
return;
ret = strncpy_from_user(dst, src, maxlen);
if (ret < 0) { /* Failed to fetch string */
((u8 *)get_rloc_data(dest))[0] = '\0';
*(u32 *)dest = make_data_rloc(0, get_rloc_offs(rloc));
} else {
*(u32 *)dest = make_data_rloc(ret, get_rloc_offs(rloc));
}
}
static __kprobes void FETCH_FUNC_NAME(memory, string_size)(struct pt_regs *regs,
void *addr, void *dest)
{
int len;
void __user *vaddr = (void __force __user *) addr;
len = strnlen_user(vaddr, MAX_STRING_SIZE);
if (len == 0 || len > MAX_STRING_SIZE) /* Failed to check length */
*(u32 *)dest = 0;
else
*(u32 *)dest = len;
}
/* uprobes do not support symbol fetch methods */
#define fetch_symbol_u8 NULL
#define fetch_symbol_u16 NULL
#define fetch_symbol_u32 NULL
#define fetch_symbol_u64 NULL
#define fetch_symbol_string NULL
#define fetch_symbol_string_size NULL
/* Fetch type information table */
const struct fetch_type uprobes_fetch_type_table[] = {
/* Special types */
[FETCH_TYPE_STRING] = __ASSIGN_FETCH_TYPE("string", string, string,
sizeof(u32), 1, "__data_loc char[]"),
[FETCH_TYPE_STRSIZE] = __ASSIGN_FETCH_TYPE("string_size", u32,
string_size, sizeof(u32), 0, "u32"),
/* Basic types */
ASSIGN_FETCH_TYPE(u8, u8, 0),
ASSIGN_FETCH_TYPE(u16, u16, 0),
ASSIGN_FETCH_TYPE(u32, u32, 0),
ASSIGN_FETCH_TYPE(u64, u64, 0),
ASSIGN_FETCH_TYPE(s8, u8, 1),
ASSIGN_FETCH_TYPE(s16, u16, 1),
ASSIGN_FETCH_TYPE(s32, u32, 1),
ASSIGN_FETCH_TYPE(s64, u64, 1),
ASSIGN_FETCH_TYPE_END
};
static inline void init_trace_uprobe_filter(struct trace_uprobe_filter *filter)
{
rwlock_init(&filter->rwlock);
filter->nr_systemwide = 0;
INIT_LIST_HEAD(&filter->perf_events);
}
static inline bool uprobe_filter_is_empty(struct trace_uprobe_filter *filter)
{
return !filter->nr_systemwide && list_empty(&filter->perf_events);
}
static inline bool is_ret_probe(struct trace_uprobe *tu)
{
return tu->consumer.ret_handler != NULL;
}
/*
* Allocate new trace_uprobe and initialize it (including uprobes).
*/
static struct trace_uprobe *
alloc_trace_uprobe(const char *group, const char *event, int nargs, bool is_ret)
{
struct trace_uprobe *tu;
if (!event || !is_good_name(event))
return ERR_PTR(-EINVAL);
if (!group || !is_good_name(group))
return ERR_PTR(-EINVAL);
tu = kzalloc(SIZEOF_TRACE_UPROBE(nargs), GFP_KERNEL);
if (!tu)
return ERR_PTR(-ENOMEM);
tu->tp.call.class = &tu->tp.class;
tu->tp.call.name = kstrdup(event, GFP_KERNEL);
if (!tu->tp.call.name)
goto error;
tu->tp.class.system = kstrdup(group, GFP_KERNEL);
if (!tu->tp.class.system)
goto error;
INIT_LIST_HEAD(&tu->list);
tu->consumer.handler = uprobe_dispatcher;
if (is_ret)
tu->consumer.ret_handler = uretprobe_dispatcher;
init_trace_uprobe_filter(&tu->filter);
tu->tp.call.flags |= TRACE_EVENT_FL_USE_CALL_FILTER;
return tu;
error:
kfree(tu->tp.call.name);
kfree(tu);
return ERR_PTR(-ENOMEM);
}
static void free_trace_uprobe(struct trace_uprobe *tu)
{
int i;
for (i = 0; i < tu->tp.nr_args; i++)
traceprobe_free_probe_arg(&tu->tp.args[i]);
iput(tu->inode);
kfree(tu->tp.call.class->system);
kfree(tu->tp.call.name);
kfree(tu->filename);
kfree(tu);
}
static struct trace_uprobe *find_probe_event(const char *event, const char *group)
{
struct trace_uprobe *tu;
list_for_each_entry(tu, &uprobe_list, list)
if (strcmp(tu->tp.call.name, event) == 0 &&
strcmp(tu->tp.call.class->system, group) == 0)
return tu;
return NULL;
}
/* Unregister a trace_uprobe and probe_event: call with locking uprobe_lock */
static int unregister_trace_uprobe(struct trace_uprobe *tu)
{
int ret;
ret = unregister_uprobe_event(tu);
if (ret)
return ret;
list_del(&tu->list);
free_trace_uprobe(tu);
return 0;
}
/* Register a trace_uprobe and probe_event */
static int register_trace_uprobe(struct trace_uprobe *tu)
{
struct trace_uprobe *old_tu;
int ret;
mutex_lock(&uprobe_lock);
/* register as an event */
old_tu = find_probe_event(tu->tp.call.name, tu->tp.call.class->system);
if (old_tu) {
/* delete old event */
ret = unregister_trace_uprobe(old_tu);
if (ret)
goto end;
}
ret = register_uprobe_event(tu);
if (ret) {
pr_warning("Failed to register probe event(%d)\n", ret);
goto end;
}
list_add_tail(&tu->list, &uprobe_list);
end:
mutex_unlock(&uprobe_lock);
return ret;
}
/*
* Argument syntax:
* - Add uprobe: p|r[:[GRP/]EVENT] PATH:OFFSET [FETCHARGS]
*
* - Remove uprobe: -:[GRP/]EVENT
*/
static int create_trace_uprobe(int argc, char **argv)
{
struct trace_uprobe *tu;
struct inode *inode;
char *arg, *event, *group, *filename;
char buf[MAX_EVENT_NAME_LEN];
struct path path;
unsigned long offset;
bool is_delete, is_return;
int i, ret;
inode = NULL;
ret = 0;
is_delete = false;
is_return = false;
event = NULL;
group = NULL;
/* argc must be >= 1 */
if (argv[0][0] == '-')
is_delete = true;
else if (argv[0][0] == 'r')
is_return = true;
else if (argv[0][0] != 'p') {
pr_info("Probe definition must be started with 'p', 'r' or '-'.\n");
return -EINVAL;
}
if (argv[0][1] == ':') {
event = &argv[0][2];
arg = strchr(event, '/');
if (arg) {
group = event;
event = arg + 1;
event[-1] = '\0';
if (strlen(group) == 0) {
pr_info("Group name is not specified\n");
return -EINVAL;
}
}
if (strlen(event) == 0) {
pr_info("Event name is not specified\n");
return -EINVAL;
}
}
if (!group)
group = UPROBE_EVENT_SYSTEM;
if (is_delete) {
int ret;
if (!event) {
pr_info("Delete command needs an event name.\n");
return -EINVAL;
}
mutex_lock(&uprobe_lock);
tu = find_probe_event(event, group);
if (!tu) {
mutex_unlock(&uprobe_lock);
pr_info("Event %s/%s doesn't exist.\n", group, event);
return -ENOENT;
}
/* delete an event */
ret = unregister_trace_uprobe(tu);
mutex_unlock(&uprobe_lock);
return ret;
}
if (argc < 2) {
pr_info("Probe point is not specified.\n");
return -EINVAL;
}
if (isdigit(argv[1][0])) {
pr_info("probe point must be have a filename.\n");
return -EINVAL;
}
arg = strchr(argv[1], ':');
if (!arg) {
ret = -EINVAL;
goto fail_address_parse;
}
*arg++ = '\0';
filename = argv[1];
ret = kern_path(filename, LOOKUP_FOLLOW, &path);
if (ret)
goto fail_address_parse;
inode = igrab(path.dentry->d_inode);
path_put(&path);
if (!inode || !S_ISREG(inode->i_mode)) {
ret = -EINVAL;
goto fail_address_parse;
}
ret = kstrtoul(arg, 0, &offset);
if (ret)
goto fail_address_parse;
argc -= 2;
argv += 2;
/* setup a probe */
if (!event) {
char *tail;
char *ptr;
tail = kstrdup(kbasename(filename), GFP_KERNEL);
if (!tail) {
ret = -ENOMEM;
goto fail_address_parse;
}
ptr = strpbrk(tail, ".-_");
if (ptr)
*ptr = '\0';
snprintf(buf, MAX_EVENT_NAME_LEN, "%c_%s_0x%lx", 'p', tail, offset);
event = buf;
kfree(tail);
}
tu = alloc_trace_uprobe(group, event, argc, is_return);
if (IS_ERR(tu)) {
pr_info("Failed to allocate trace_uprobe.(%d)\n", (int)PTR_ERR(tu));
ret = PTR_ERR(tu);
goto fail_address_parse;
}
tu->offset = offset;
tu->inode = inode;
tu->filename = kstrdup(filename, GFP_KERNEL);
if (!tu->filename) {
pr_info("Failed to allocate filename.\n");
ret = -ENOMEM;
goto error;
}
/* parse arguments */
ret = 0;
for (i = 0; i < argc && i < MAX_TRACE_ARGS; i++) {
struct probe_arg *parg = &tu->tp.args[i];
/* Increment count for freeing args in error case */
tu->tp.nr_args++;
/* Parse argument name */
arg = strchr(argv[i], '=');
if (arg) {
*arg++ = '\0';
parg->name = kstrdup(argv[i], GFP_KERNEL);
} else {
arg = argv[i];
/* If argument name is omitted, set "argN" */
snprintf(buf, MAX_EVENT_NAME_LEN, "arg%d", i + 1);
parg->name = kstrdup(buf, GFP_KERNEL);
}
if (!parg->name) {
pr_info("Failed to allocate argument[%d] name.\n", i);
ret = -ENOMEM;
goto error;
}
if (!is_good_name(parg->name)) {
pr_info("Invalid argument[%d] name: %s\n", i, parg->name);
ret = -EINVAL;
goto error;
}
if (traceprobe_conflict_field_name(parg->name, tu->tp.args, i)) {
pr_info("Argument[%d] name '%s' conflicts with "
"another field.\n", i, argv[i]);
ret = -EINVAL;
goto error;
}
/* Parse fetch argument */
ret = traceprobe_parse_probe_arg(arg, &tu->tp.size, parg,
false, false);
if (ret) {
pr_info("Parse error at argument[%d]. (%d)\n", i, ret);
goto error;
}
}
ret = register_trace_uprobe(tu);
if (ret)
goto error;
return 0;
error:
free_trace_uprobe(tu);
return ret;
fail_address_parse:
if (inode)
iput(inode);
pr_info("Failed to parse address or file.\n");
return ret;
}
static int cleanup_all_probes(void)
{
struct trace_uprobe *tu;
int ret = 0;
mutex_lock(&uprobe_lock);
while (!list_empty(&uprobe_list)) {
tu = list_entry(uprobe_list.next, struct trace_uprobe, list);
ret = unregister_trace_uprobe(tu);
if (ret)
break;
}
mutex_unlock(&uprobe_lock);
return ret;
}
/* Probes listing interfaces */
static void *probes_seq_start(struct seq_file *m, loff_t *pos)
{
mutex_lock(&uprobe_lock);
return seq_list_start(&uprobe_list, *pos);
}
static void *probes_seq_next(struct seq_file *m, void *v, loff_t *pos)
{
return seq_list_next(v, &uprobe_list, pos);
}
static void probes_seq_stop(struct seq_file *m, void *v)
{
mutex_unlock(&uprobe_lock);
}
static int probes_seq_show(struct seq_file *m, void *v)
{
struct trace_uprobe *tu = v;
char c = is_ret_probe(tu) ? 'r' : 'p';
int i;
seq_printf(m, "%c:%s/%s", c, tu->tp.call.class->system, tu->tp.call.name);
seq_printf(m, " %s:0x%p", tu->filename, (void *)tu->offset);
for (i = 0; i < tu->tp.nr_args; i++)
seq_printf(m, " %s=%s", tu->tp.args[i].name, tu->tp.args[i].comm);
seq_printf(m, "\n");
return 0;
}
static const struct seq_operations probes_seq_op = {
.start = probes_seq_start,
.next = probes_seq_next,
.stop = probes_seq_stop,
.show = probes_seq_show
};
static int probes_open(struct inode *inode, struct file *file)
{
int ret;
if ((file->f_mode & FMODE_WRITE) && (file->f_flags & O_TRUNC)) {
ret = cleanup_all_probes();
if (ret)
return ret;
}
return seq_open(file, &probes_seq_op);
}
static ssize_t probes_write(struct file *file, const char __user *buffer,
size_t count, loff_t *ppos)
{
return traceprobe_probes_write(file, buffer, count, ppos, create_trace_uprobe);
}
static const struct file_operations uprobe_events_ops = {
.owner = THIS_MODULE,
.open = probes_open,
.read = seq_read,
.llseek = seq_lseek,
.release = seq_release,
.write = probes_write,
};
/* Probes profiling interfaces */
static int probes_profile_seq_show(struct seq_file *m, void *v)
{
struct trace_uprobe *tu = v;
seq_printf(m, " %s %-44s %15lu\n", tu->filename, tu->tp.call.name, tu->nhit);
return 0;
}
static const struct seq_operations profile_seq_op = {
.start = probes_seq_start,
.next = probes_seq_next,
.stop = probes_seq_stop,
.show = probes_profile_seq_show
};
static int profile_open(struct inode *inode, struct file *file)
{
return seq_open(file, &profile_seq_op);
}
static const struct file_operations uprobe_profile_ops = {
.owner = THIS_MODULE,
.open = profile_open,
.read = seq_read,
.llseek = seq_lseek,
.release = seq_release,
};
static void uprobe_trace_print(struct trace_uprobe *tu,
unsigned long func, struct pt_regs *regs)
{
struct uprobe_trace_entry_head *entry;
struct ring_buffer_event *event;
struct ring_buffer *buffer;
void *data;
int size, i;
struct ftrace_event_call *call = &tu->tp.call;
size = SIZEOF_TRACE_ENTRY(is_ret_probe(tu));
event = trace_current_buffer_lock_reserve(&buffer, call->event.type,
size + tu->tp.size, 0, 0);
if (!event)
return;
entry = ring_buffer_event_data(event);
if (is_ret_probe(tu)) {
entry->vaddr[0] = func;
entry->vaddr[1] = instruction_pointer(regs);
data = DATAOF_TRACE_ENTRY(entry, true);
} else {
entry->vaddr[0] = instruction_pointer(regs);
data = DATAOF_TRACE_ENTRY(entry, false);
}
for (i = 0; i < tu->tp.nr_args; i++) {
call_fetch(&tu->tp.args[i].fetch, regs,
data + tu->tp.args[i].offset);
}
if (!call_filter_check_discard(call, entry, buffer, event))
trace_buffer_unlock_commit(buffer, event, 0, 0);
}
/* uprobe handler */
static int uprobe_trace_func(struct trace_uprobe *tu, struct pt_regs *regs)
{
if (!is_ret_probe(tu))
uprobe_trace_print(tu, 0, regs);
return 0;
}
static void uretprobe_trace_func(struct trace_uprobe *tu, unsigned long func,
struct pt_regs *regs)
{
uprobe_trace_print(tu, func, regs);
}
/* Event entry printers */
static enum print_line_t
print_uprobe_event(struct trace_iterator *iter, int flags, struct trace_event *event)
{
struct uprobe_trace_entry_head *entry;
struct trace_seq *s = &iter->seq;
struct trace_uprobe *tu;
u8 *data;
int i;
entry = (struct uprobe_trace_entry_head *)iter->ent;
tu = container_of(event, struct trace_uprobe, tp.call.event);
if (is_ret_probe(tu)) {
if (!trace_seq_printf(s, "%s: (0x%lx <- 0x%lx)", tu->tp.call.name,
entry->vaddr[1], entry->vaddr[0]))
goto partial;
data = DATAOF_TRACE_ENTRY(entry, true);
} else {
if (!trace_seq_printf(s, "%s: (0x%lx)", tu->tp.call.name,
entry->vaddr[0]))
goto partial;
data = DATAOF_TRACE_ENTRY(entry, false);
}
for (i = 0; i < tu->tp.nr_args; i++) {
struct probe_arg *parg = &tu->tp.args[i];
if (!parg->type->print(s, parg->name, data + parg->offset, entry))
goto partial;
}
if (trace_seq_puts(s, "\n"))
return TRACE_TYPE_HANDLED;
partial:
return TRACE_TYPE_PARTIAL_LINE;
}
typedef bool (*filter_func_t)(struct uprobe_consumer *self,
enum uprobe_filter_ctx ctx,
struct mm_struct *mm);
static int
probe_event_enable(struct trace_uprobe *tu, int flag, filter_func_t filter)
{
int ret = 0;
if (trace_probe_is_enabled(&tu->tp))
return -EINTR;
WARN_ON(!uprobe_filter_is_empty(&tu->filter));
tu->tp.flags |= flag;
tu->consumer.filter = filter;
ret = uprobe_register(tu->inode, tu->offset, &tu->consumer);
if (ret)
tu->tp.flags &= ~flag;
return ret;
}
static void probe_event_disable(struct trace_uprobe *tu, int flag)
{
if (!trace_probe_is_enabled(&tu->tp))
return;
WARN_ON(!uprobe_filter_is_empty(&tu->filter));
uprobe_unregister(tu->inode, tu->offset, &tu->consumer);
tu->tp.flags &= ~flag;
}
static int uprobe_event_define_fields(struct ftrace_event_call *event_call)
{
int ret, i, size;
struct uprobe_trace_entry_head field;
struct trace_uprobe *tu = event_call->data;
if (is_ret_probe(tu)) {
DEFINE_FIELD(unsigned long, vaddr[0], FIELD_STRING_FUNC, 0);
DEFINE_FIELD(unsigned long, vaddr[1], FIELD_STRING_RETIP, 0);
size = SIZEOF_TRACE_ENTRY(true);
} else {
DEFINE_FIELD(unsigned long, vaddr[0], FIELD_STRING_IP, 0);
size = SIZEOF_TRACE_ENTRY(false);
}
/* Set argument names as fields */
for (i = 0; i < tu->tp.nr_args; i++) {
struct probe_arg *parg = &tu->tp.args[i];
ret = trace_define_field(event_call, parg->type->fmttype,
parg->name, size + parg->offset,
parg->type->size, parg->type->is_signed,
FILTER_OTHER);
if (ret)
return ret;
}
return 0;
}
#ifdef CONFIG_PERF_EVENTS
static bool
__uprobe_perf_filter(struct trace_uprobe_filter *filter, struct mm_struct *mm)
{
struct perf_event *event;
if (filter->nr_systemwide)
return true;
list_for_each_entry(event, &filter->perf_events, hw.tp_list) {
if (event->hw.tp_target->mm == mm)
return true;
}
return false;
}
static inline bool
uprobe_filter_event(struct trace_uprobe *tu, struct perf_event *event)
{
return __uprobe_perf_filter(&tu->filter, event->hw.tp_target->mm);
}
static int uprobe_perf_open(struct trace_uprobe *tu, struct perf_event *event)
{
bool done;
write_lock(&tu->filter.rwlock);
if (event->hw.tp_target) {
/*
* event->parent != NULL means copy_process(), we can avoid
* uprobe_apply(). current->mm must be probed and we can rely
* on dup_mmap() which preserves the already installed bp's.
*
* attr.enable_on_exec means that exec/mmap will install the
* breakpoints we need.
*/
done = tu->filter.nr_systemwide ||
event->parent || event->attr.enable_on_exec ||
uprobe_filter_event(tu, event);
list_add(&event->hw.tp_list, &tu->filter.perf_events);
} else {
done = tu->filter.nr_systemwide;
tu->filter.nr_systemwide++;
}
write_unlock(&tu->filter.rwlock);
if (!done)
uprobe_apply(tu->inode, tu->offset, &tu->consumer, true);
return 0;
}
static int uprobe_perf_close(struct trace_uprobe *tu, struct perf_event *event)
{
bool done;
write_lock(&tu->filter.rwlock);
if (event->hw.tp_target) {
list_del(&event->hw.tp_list);
done = tu->filter.nr_systemwide ||
(event->hw.tp_target->flags & PF_EXITING) ||
uprobe_filter_event(tu, event);
} else {
tu->filter.nr_systemwide--;
done = tu->filter.nr_systemwide;
}
write_unlock(&tu->filter.rwlock);
if (!done)
uprobe_apply(tu->inode, tu->offset, &tu->consumer, false);
return 0;
}
static bool uprobe_perf_filter(struct uprobe_consumer *uc,
enum uprobe_filter_ctx ctx, struct mm_struct *mm)
{
struct trace_uprobe *tu;
int ret;
tu = container_of(uc, struct trace_uprobe, consumer);
read_lock(&tu->filter.rwlock);
ret = __uprobe_perf_filter(&tu->filter, mm);
read_unlock(&tu->filter.rwlock);
return ret;
}
static void uprobe_perf_print(struct trace_uprobe *tu,
unsigned long func, struct pt_regs *regs)
{
struct ftrace_event_call *call = &tu->tp.call;
struct uprobe_trace_entry_head *entry;
struct hlist_head *head;
void *data;
int size, rctx, i;
size = SIZEOF_TRACE_ENTRY(is_ret_probe(tu));
size = ALIGN(size + tu->tp.size + sizeof(u32), sizeof(u64)) - sizeof(u32);
preempt_disable();
head = this_cpu_ptr(call->perf_events);
if (hlist_empty(head))
goto out;
entry = perf_trace_buf_prepare(size, call->event.type, regs, &rctx);
if (!entry)
goto out;
if (is_ret_probe(tu)) {
entry->vaddr[0] = func;
entry->vaddr[1] = instruction_pointer(regs);
data = DATAOF_TRACE_ENTRY(entry, true);
} else {
entry->vaddr[0] = instruction_pointer(regs);
data = DATAOF_TRACE_ENTRY(entry, false);
}
for (i = 0; i < tu->tp.nr_args; i++) {
struct probe_arg *parg = &tu->tp.args[i];
call_fetch(&parg->fetch, regs, data + parg->offset);
}
perf_trace_buf_submit(entry, size, rctx, 0, 1, regs, head, NULL);
out:
preempt_enable();
}
/* uprobe profile handler */
static int uprobe_perf_func(struct trace_uprobe *tu, struct pt_regs *regs)
{
if (!uprobe_perf_filter(&tu->consumer, 0, current->mm))
return UPROBE_HANDLER_REMOVE;
if (!is_ret_probe(tu))
uprobe_perf_print(tu, 0, regs);
return 0;
}
static void uretprobe_perf_func(struct trace_uprobe *tu, unsigned long func,
struct pt_regs *regs)
{
uprobe_perf_print(tu, func, regs);
}
#endif /* CONFIG_PERF_EVENTS */
static
int trace_uprobe_register(struct ftrace_event_call *event, enum trace_reg type, void *data)
{
struct trace_uprobe *tu = event->data;
switch (type) {
case TRACE_REG_REGISTER:
return probe_event_enable(tu, TP_FLAG_TRACE, NULL);
case TRACE_REG_UNREGISTER:
probe_event_disable(tu, TP_FLAG_TRACE);
return 0;
#ifdef CONFIG_PERF_EVENTS
case TRACE_REG_PERF_REGISTER:
return probe_event_enable(tu, TP_FLAG_PROFILE, uprobe_perf_filter);
case TRACE_REG_PERF_UNREGISTER:
probe_event_disable(tu, TP_FLAG_PROFILE);
return 0;
case TRACE_REG_PERF_OPEN:
return uprobe_perf_open(tu, data);
case TRACE_REG_PERF_CLOSE:
return uprobe_perf_close(tu, data);
#endif
default:
return 0;
}
return 0;
}
static int uprobe_dispatcher(struct uprobe_consumer *con, struct pt_regs *regs)
{
struct trace_uprobe *tu;
int ret = 0;
tu = container_of(con, struct trace_uprobe, consumer);
tu->nhit++;
if (tu->tp.flags & TP_FLAG_TRACE)
ret |= uprobe_trace_func(tu, regs);
#ifdef CONFIG_PERF_EVENTS
if (tu->tp.flags & TP_FLAG_PROFILE)
ret |= uprobe_perf_func(tu, regs);
#endif
return ret;
}
static int uretprobe_dispatcher(struct uprobe_consumer *con,
unsigned long func, struct pt_regs *regs)
{
struct trace_uprobe *tu;
tu = container_of(con, struct trace_uprobe, consumer);
if (tu->tp.flags & TP_FLAG_TRACE)
uretprobe_trace_func(tu, func, regs);
#ifdef CONFIG_PERF_EVENTS
if (tu->tp.flags & TP_FLAG_PROFILE)
uretprobe_perf_func(tu, func, regs);
#endif
return 0;
}
static struct trace_event_functions uprobe_funcs = {
.trace = print_uprobe_event
};
static int register_uprobe_event(struct trace_uprobe *tu)
{
struct ftrace_event_call *call = &tu->tp.call;
int ret;
/* Initialize ftrace_event_call */
INIT_LIST_HEAD(&call->class->fields);
call->event.funcs = &uprobe_funcs;
call->class->define_fields = uprobe_event_define_fields;
if (set_print_fmt(&tu->tp, is_ret_probe(tu)) < 0)
return -ENOMEM;
ret = register_ftrace_event(&call->event);
if (!ret) {
kfree(call->print_fmt);
return -ENODEV;
}
call->flags = 0;
call->class->reg = trace_uprobe_register;
call->data = tu;
ret = trace_add_event_call(call);
if (ret) {
pr_info("Failed to register uprobe event: %s\n", call->name);
kfree(call->print_fmt);
unregister_ftrace_event(&call->event);
}
return ret;
}
static int unregister_uprobe_event(struct trace_uprobe *tu)
{
int ret;
/* tu->event is unregistered in trace_remove_event_call() */
ret = trace_remove_event_call(&tu->tp.call);
if (ret)
return ret;
kfree(tu->tp.call.print_fmt);
tu->tp.call.print_fmt = NULL;
return 0;
}
/* Make a trace interface for controling probe points */
static __init int init_uprobe_trace(void)
{
struct dentry *d_tracer;
d_tracer = tracing_init_dentry();
if (!d_tracer)
return 0;
trace_create_file("uprobe_events", 0644, d_tracer,
NULL, &uprobe_events_ops);
/* Profile interface */
trace_create_file("uprobe_profile", 0444, d_tracer,
NULL, &uprobe_profile_ops);
return 0;
}
fs_initcall(init_uprobe_trace);
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