linux/kernel/trace/trace_uprobe.c
Andrii Nakryiko 699646734a uprobes: prevent mutex_lock() under rcu_read_lock()
Recent changes made uprobe_cpu_buffer preparation lazy, and moved it
deeper into __uprobe_trace_func(). This is problematic because
__uprobe_trace_func() is called inside rcu_read_lock()/rcu_read_unlock()
block, which then calls prepare_uprobe_buffer() -> uprobe_buffer_get() ->
mutex_lock(&ucb->mutex), leading to a splat about using mutex under
non-sleepable RCU:

  BUG: sleeping function called from invalid context at kernel/locking/mutex.c:585
   in_atomic(): 0, irqs_disabled(): 0, non_block: 0, pid: 98231, name: stress-ng-sigq
   preempt_count: 0, expected: 0
   RCU nest depth: 1, expected: 0
   ...
   Call Trace:
    <TASK>
    dump_stack_lvl+0x3d/0xe0
    __might_resched+0x24c/0x270
    ? prepare_uprobe_buffer+0xd5/0x1d0
    __mutex_lock+0x41/0x820
    ? ___perf_sw_event+0x206/0x290
    ? __perf_event_task_sched_in+0x54/0x660
    ? __perf_event_task_sched_in+0x54/0x660
    prepare_uprobe_buffer+0xd5/0x1d0
    __uprobe_trace_func+0x4a/0x140
    uprobe_dispatcher+0x135/0x280
    ? uprobe_dispatcher+0x94/0x280
    uprobe_notify_resume+0x650/0xec0
    ? atomic_notifier_call_chain+0x21/0x110
    ? atomic_notifier_call_chain+0xf8/0x110
    irqentry_exit_to_user_mode+0xe2/0x1e0
    asm_exc_int3+0x35/0x40
   RIP: 0033:0x7f7e1d4da390
   Code: 33 04 00 0f 1f 80 00 00 00 00 f3 0f 1e fa b9 01 00 00 00 e9 b2 fc ff ff 66 90 f3 0f 1e fa 31 c9 e9 a5 fc ff ff 0f 1f 44 00 00 <cc> 0f 1e fa b8 27 00 00 00 0f 05 c3 0f 1f 40 00 f3 0f 1e fa b8 6e
   RSP: 002b:00007ffd2abc3608 EFLAGS: 00000246
   RAX: 0000000000000000 RBX: 0000000076d325f1 RCX: 0000000000000000
   RDX: 0000000076d325f1 RSI: 000000000000000a RDI: 00007ffd2abc3690
   RBP: 000000000000000a R08: 00017fb700000000 R09: 00017fb700000000
   R10: 00017fb700000000 R11: 0000000000000246 R12: 0000000000017ff2
   R13: 00007ffd2abc3610 R14: 0000000000000000 R15: 00007ffd2abc3780
    </TASK>

Luckily, it's easy to fix by moving prepare_uprobe_buffer() to be called
slightly earlier: into uprobe_trace_func() and uretprobe_trace_func(), outside
of RCU locked section. This still keeps this buffer preparation lazy and helps
avoid the overhead when it's not needed. E.g., if there is only BPF uprobe
handler installed on a given uprobe, buffer won't be initialized.

Note, the other user of prepare_uprobe_buffer(), __uprobe_perf_func(), is not
affected, as it doesn't prepare buffer under RCU read lock.

Link: https://lore.kernel.org/all/20240521053017.3708530-1-andrii@kernel.org/

Fixes: 1b8f85defb ("uprobes: prepare uprobe args buffer lazily")
Reported-by: Breno Leitao <leitao@debian.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
2024-05-24 07:44:44 +09:00

1685 lines
38 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* uprobes-based tracing events
*
* Copyright (C) IBM Corporation, 2010-2012
* Author: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
*/
#define pr_fmt(fmt) "trace_uprobe: " fmt
#include <linux/bpf-cgroup.h>
#include <linux/security.h>
#include <linux/ctype.h>
#include <linux/module.h>
#include <linux/uaccess.h>
#include <linux/uprobes.h>
#include <linux/namei.h>
#include <linux/string.h>
#include <linux/rculist.h>
#include <linux/filter.h>
#include "trace_dynevent.h"
#include "trace_probe.h"
#include "trace_probe_tmpl.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))
static int trace_uprobe_create(const char *raw_command);
static int trace_uprobe_show(struct seq_file *m, struct dyn_event *ev);
static int trace_uprobe_release(struct dyn_event *ev);
static bool trace_uprobe_is_busy(struct dyn_event *ev);
static bool trace_uprobe_match(const char *system, const char *event,
int argc, const char **argv, struct dyn_event *ev);
static struct dyn_event_operations trace_uprobe_ops = {
.create = trace_uprobe_create,
.show = trace_uprobe_show,
.is_busy = trace_uprobe_is_busy,
.free = trace_uprobe_release,
.match = trace_uprobe_match,
};
/*
* uprobe event core functions
*/
struct trace_uprobe {
struct dyn_event devent;
struct uprobe_consumer consumer;
struct path path;
struct inode *inode;
char *filename;
unsigned long offset;
unsigned long ref_ctr_offset;
unsigned long nhit;
struct trace_probe tp;
};
static bool is_trace_uprobe(struct dyn_event *ev)
{
return ev->ops == &trace_uprobe_ops;
}
static struct trace_uprobe *to_trace_uprobe(struct dyn_event *ev)
{
return container_of(ev, struct trace_uprobe, devent);
}
/**
* for_each_trace_uprobe - iterate over the trace_uprobe list
* @pos: the struct trace_uprobe * for each entry
* @dpos: the struct dyn_event * to use as a loop cursor
*/
#define for_each_trace_uprobe(pos, dpos) \
for_each_dyn_event(dpos) \
if (is_trace_uprobe(dpos) && (pos = to_trace_uprobe(dpos)))
static int register_uprobe_event(struct trace_uprobe *tu);
static int unregister_uprobe_event(struct trace_uprobe *tu);
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
*/
static nokprobe_inline int
probe_mem_read(void *dest, void *src, size_t size)
{
void __user *vaddr = (void __force __user *)src;
return copy_from_user(dest, vaddr, size) ? -EFAULT : 0;
}
static nokprobe_inline int
probe_mem_read_user(void *dest, void *src, size_t size)
{
return probe_mem_read(dest, src, size);
}
/*
* Fetch a null-terminated string. Caller MUST set *(u32 *)dest with max
* length and relative data location.
*/
static nokprobe_inline int
fetch_store_string(unsigned long addr, void *dest, void *base)
{
long ret;
u32 loc = *(u32 *)dest;
int maxlen = get_loc_len(loc);
u8 *dst = get_loc_data(dest, base);
void __user *src = (void __force __user *) addr;
if (unlikely(!maxlen))
return -ENOMEM;
if (addr == FETCH_TOKEN_COMM)
ret = strscpy(dst, current->comm, maxlen);
else
ret = strncpy_from_user(dst, src, maxlen);
if (ret >= 0) {
if (ret == maxlen)
dst[ret - 1] = '\0';
else
/*
* Include the terminating null byte. In this case it
* was copied by strncpy_from_user but not accounted
* for in ret.
*/
ret++;
*(u32 *)dest = make_data_loc(ret, (void *)dst - base);
} else
*(u32 *)dest = make_data_loc(0, (void *)dst - base);
return ret;
}
static nokprobe_inline int
fetch_store_string_user(unsigned long addr, void *dest, void *base)
{
return fetch_store_string(addr, dest, base);
}
/* Return the length of string -- including null terminal byte */
static nokprobe_inline int
fetch_store_strlen(unsigned long addr)
{
int len;
void __user *vaddr = (void __force __user *) addr;
if (addr == FETCH_TOKEN_COMM)
len = strlen(current->comm) + 1;
else
len = strnlen_user(vaddr, MAX_STRING_SIZE);
return (len > MAX_STRING_SIZE) ? 0 : len;
}
static nokprobe_inline int
fetch_store_strlen_user(unsigned long addr)
{
return fetch_store_strlen(addr);
}
static unsigned long translate_user_vaddr(unsigned long file_offset)
{
unsigned long base_addr;
struct uprobe_dispatch_data *udd;
udd = (void *) current->utask->vaddr;
base_addr = udd->bp_addr - udd->tu->offset;
return base_addr + file_offset;
}
/* 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 *edata,
void *dest, void *base)
{
struct pt_regs *regs = rec;
unsigned long val;
int ret;
/* 1st stage: get value from context */
switch (code->op) {
case FETCH_OP_REG:
val = regs_get_register(regs, code->param);
break;
case FETCH_OP_STACK:
val = get_user_stack_nth(regs, code->param);
break;
case FETCH_OP_STACKP:
val = user_stack_pointer(regs);
break;
case FETCH_OP_RETVAL:
val = regs_return_value(regs);
break;
case FETCH_OP_COMM:
val = FETCH_TOKEN_COMM;
break;
case FETCH_OP_FOFFS:
val = translate_user_vaddr(code->immediate);
break;
default:
ret = process_common_fetch_insn(code, &val);
if (ret < 0)
return ret;
}
code++;
return process_fetch_insn_bottom(code, val, dest, base);
}
NOKPROBE_SYMBOL(process_fetch_insn)
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;
}
static bool trace_uprobe_is_busy(struct dyn_event *ev)
{
struct trace_uprobe *tu = to_trace_uprobe(ev);
return trace_probe_is_enabled(&tu->tp);
}
static bool trace_uprobe_match_command_head(struct trace_uprobe *tu,
int argc, const char **argv)
{
char buf[MAX_ARGSTR_LEN + 1];
int len;
if (!argc)
return true;
len = strlen(tu->filename);
if (strncmp(tu->filename, argv[0], len) || argv[0][len] != ':')
return false;
if (tu->ref_ctr_offset == 0)
snprintf(buf, sizeof(buf), "0x%0*lx",
(int)(sizeof(void *) * 2), tu->offset);
else
snprintf(buf, sizeof(buf), "0x%0*lx(0x%lx)",
(int)(sizeof(void *) * 2), tu->offset,
tu->ref_ctr_offset);
if (strcmp(buf, &argv[0][len + 1]))
return false;
argc--; argv++;
return trace_probe_match_command_args(&tu->tp, argc, argv);
}
static bool trace_uprobe_match(const char *system, const char *event,
int argc, const char **argv, struct dyn_event *ev)
{
struct trace_uprobe *tu = to_trace_uprobe(ev);
return (event[0] == '\0' ||
strcmp(trace_probe_name(&tu->tp), event) == 0) &&
(!system || strcmp(trace_probe_group_name(&tu->tp), system) == 0) &&
trace_uprobe_match_command_head(tu, argc, argv);
}
static nokprobe_inline struct trace_uprobe *
trace_uprobe_primary_from_call(struct trace_event_call *call)
{
struct trace_probe *tp;
tp = trace_probe_primary_from_call(call);
if (WARN_ON_ONCE(!tp))
return NULL;
return container_of(tp, struct trace_uprobe, tp);
}
/*
* 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;
int ret;
tu = kzalloc(struct_size(tu, tp.args, nargs), GFP_KERNEL);
if (!tu)
return ERR_PTR(-ENOMEM);
ret = trace_probe_init(&tu->tp, event, group, true, nargs);
if (ret < 0)
goto error;
dyn_event_init(&tu->devent, &trace_uprobe_ops);
tu->consumer.handler = uprobe_dispatcher;
if (is_ret)
tu->consumer.ret_handler = uretprobe_dispatcher;
init_trace_uprobe_filter(tu->tp.event->filter);
return tu;
error:
kfree(tu);
return ERR_PTR(ret);
}
static void free_trace_uprobe(struct trace_uprobe *tu)
{
if (!tu)
return;
path_put(&tu->path);
trace_probe_cleanup(&tu->tp);
kfree(tu->filename);
kfree(tu);
}
static struct trace_uprobe *find_probe_event(const char *event, const char *group)
{
struct dyn_event *pos;
struct trace_uprobe *tu;
for_each_trace_uprobe(tu, pos)
if (strcmp(trace_probe_name(&tu->tp), event) == 0 &&
strcmp(trace_probe_group_name(&tu->tp), group) == 0)
return tu;
return NULL;
}
/* Unregister a trace_uprobe and probe_event */
static int unregister_trace_uprobe(struct trace_uprobe *tu)
{
int ret;
if (trace_probe_has_sibling(&tu->tp))
goto unreg;
/* If there's a reference to the dynamic event */
if (trace_event_dyn_busy(trace_probe_event_call(&tu->tp)))
return -EBUSY;
ret = unregister_uprobe_event(tu);
if (ret)
return ret;
unreg:
dyn_event_remove(&tu->devent);
trace_probe_unlink(&tu->tp);
free_trace_uprobe(tu);
return 0;
}
static bool trace_uprobe_has_same_uprobe(struct trace_uprobe *orig,
struct trace_uprobe *comp)
{
struct trace_probe_event *tpe = orig->tp.event;
struct inode *comp_inode = d_real_inode(comp->path.dentry);
int i;
list_for_each_entry(orig, &tpe->probes, tp.list) {
if (comp_inode != d_real_inode(orig->path.dentry) ||
comp->offset != orig->offset)
continue;
/*
* trace_probe_compare_arg_type() ensured that nr_args and
* each argument name and type are same. Let's compare comm.
*/
for (i = 0; i < orig->tp.nr_args; i++) {
if (strcmp(orig->tp.args[i].comm,
comp->tp.args[i].comm))
break;
}
if (i == orig->tp.nr_args)
return true;
}
return false;
}
static int append_trace_uprobe(struct trace_uprobe *tu, struct trace_uprobe *to)
{
int ret;
ret = trace_probe_compare_arg_type(&tu->tp, &to->tp);
if (ret) {
/* Note that argument starts index = 2 */
trace_probe_log_set_index(ret + 1);
trace_probe_log_err(0, DIFF_ARG_TYPE);
return -EEXIST;
}
if (trace_uprobe_has_same_uprobe(to, tu)) {
trace_probe_log_set_index(0);
trace_probe_log_err(0, SAME_PROBE);
return -EEXIST;
}
/* Append to existing event */
ret = trace_probe_append(&tu->tp, &to->tp);
if (!ret)
dyn_event_add(&tu->devent, trace_probe_event_call(&tu->tp));
return ret;
}
/*
* Uprobe with multiple reference counter is not allowed. i.e.
* If inode and offset matches, reference counter offset *must*
* match as well. Though, there is one exception: If user is
* replacing old trace_uprobe with new one(same group/event),
* then we allow same uprobe with new reference counter as far
* as the new one does not conflict with any other existing
* ones.
*/
static int validate_ref_ctr_offset(struct trace_uprobe *new)
{
struct dyn_event *pos;
struct trace_uprobe *tmp;
struct inode *new_inode = d_real_inode(new->path.dentry);
for_each_trace_uprobe(tmp, pos) {
if (new_inode == d_real_inode(tmp->path.dentry) &&
new->offset == tmp->offset &&
new->ref_ctr_offset != tmp->ref_ctr_offset) {
pr_warn("Reference counter offset mismatch.");
return -EINVAL;
}
}
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(&event_mutex);
ret = validate_ref_ctr_offset(tu);
if (ret)
goto end;
/* register as an event */
old_tu = find_probe_event(trace_probe_name(&tu->tp),
trace_probe_group_name(&tu->tp));
if (old_tu) {
if (is_ret_probe(tu) != is_ret_probe(old_tu)) {
trace_probe_log_set_index(0);
trace_probe_log_err(0, DIFF_PROBE_TYPE);
ret = -EEXIST;
} else {
ret = append_trace_uprobe(tu, old_tu);
}
goto end;
}
ret = register_uprobe_event(tu);
if (ret) {
if (ret == -EEXIST) {
trace_probe_log_set_index(0);
trace_probe_log_err(0, EVENT_EXIST);
} else
pr_warn("Failed to register probe event(%d)\n", ret);
goto end;
}
dyn_event_add(&tu->devent, trace_probe_event_call(&tu->tp));
end:
mutex_unlock(&event_mutex);
return ret;
}
/*
* Argument syntax:
* - Add uprobe: p|r[:[GRP/][EVENT]] PATH:OFFSET[%return][(REF)] [FETCHARGS]
*/
static int __trace_uprobe_create(int argc, const char **argv)
{
struct trace_uprobe *tu;
const char *event = NULL, *group = UPROBE_EVENT_SYSTEM;
char *arg, *filename, *rctr, *rctr_end, *tmp;
char buf[MAX_EVENT_NAME_LEN];
char gbuf[MAX_EVENT_NAME_LEN];
enum probe_print_type ptype;
struct path path;
unsigned long offset, ref_ctr_offset;
bool is_return = false;
int i, ret;
ref_ctr_offset = 0;
switch (argv[0][0]) {
case 'r':
is_return = true;
break;
case 'p':
break;
default:
return -ECANCELED;
}
if (argc < 2)
return -ECANCELED;
if (argv[0][1] == ':')
event = &argv[0][2];
if (!strchr(argv[1], '/'))
return -ECANCELED;
filename = kstrdup(argv[1], GFP_KERNEL);
if (!filename)
return -ENOMEM;
/* Find the last occurrence, in case the path contains ':' too. */
arg = strrchr(filename, ':');
if (!arg || !isdigit(arg[1])) {
kfree(filename);
return -ECANCELED;
}
trace_probe_log_init("trace_uprobe", argc, argv);
trace_probe_log_set_index(1); /* filename is the 2nd argument */
*arg++ = '\0';
ret = kern_path(filename, LOOKUP_FOLLOW, &path);
if (ret) {
trace_probe_log_err(0, FILE_NOT_FOUND);
kfree(filename);
trace_probe_log_clear();
return ret;
}
if (!d_is_reg(path.dentry)) {
trace_probe_log_err(0, NO_REGULAR_FILE);
ret = -EINVAL;
goto fail_address_parse;
}
/* Parse reference counter offset if specified. */
rctr = strchr(arg, '(');
if (rctr) {
rctr_end = strchr(rctr, ')');
if (!rctr_end) {
ret = -EINVAL;
rctr_end = rctr + strlen(rctr);
trace_probe_log_err(rctr_end - filename,
REFCNT_OPEN_BRACE);
goto fail_address_parse;
} else if (rctr_end[1] != '\0') {
ret = -EINVAL;
trace_probe_log_err(rctr_end + 1 - filename,
BAD_REFCNT_SUFFIX);
goto fail_address_parse;
}
*rctr++ = '\0';
*rctr_end = '\0';
ret = kstrtoul(rctr, 0, &ref_ctr_offset);
if (ret) {
trace_probe_log_err(rctr - filename, BAD_REFCNT);
goto fail_address_parse;
}
}
/* Check if there is %return suffix */
tmp = strchr(arg, '%');
if (tmp) {
if (!strcmp(tmp, "%return")) {
*tmp = '\0';
is_return = true;
} else {
trace_probe_log_err(tmp - filename, BAD_ADDR_SUFFIX);
ret = -EINVAL;
goto fail_address_parse;
}
}
/* Parse uprobe offset. */
ret = kstrtoul(arg, 0, &offset);
if (ret) {
trace_probe_log_err(arg - filename, BAD_UPROBE_OFFS);
goto fail_address_parse;
}
/* setup a probe */
trace_probe_log_set_index(0);
if (event) {
ret = traceprobe_parse_event_name(&event, &group, gbuf,
event - argv[0]);
if (ret)
goto fail_address_parse;
}
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);
}
argc -= 2;
argv += 2;
tu = alloc_trace_uprobe(group, event, argc, is_return);
if (IS_ERR(tu)) {
ret = PTR_ERR(tu);
/* This must return -ENOMEM otherwise there is a bug */
WARN_ON_ONCE(ret != -ENOMEM);
goto fail_address_parse;
}
tu->offset = offset;
tu->ref_ctr_offset = ref_ctr_offset;
tu->path = path;
tu->filename = filename;
/* parse arguments */
for (i = 0; i < argc && i < MAX_TRACE_ARGS; i++) {
struct traceprobe_parse_context ctx = {
.flags = (is_return ? TPARG_FL_RETURN : 0) | TPARG_FL_USER,
};
trace_probe_log_set_index(i + 2);
ret = traceprobe_parse_probe_arg(&tu->tp, i, argv[i], &ctx);
traceprobe_finish_parse(&ctx);
if (ret)
goto error;
}
ptype = is_ret_probe(tu) ? PROBE_PRINT_RETURN : PROBE_PRINT_NORMAL;
ret = traceprobe_set_print_fmt(&tu->tp, ptype);
if (ret < 0)
goto error;
ret = register_trace_uprobe(tu);
if (!ret)
goto out;
error:
free_trace_uprobe(tu);
out:
trace_probe_log_clear();
return ret;
fail_address_parse:
trace_probe_log_clear();
path_put(&path);
kfree(filename);
return ret;
}
int trace_uprobe_create(const char *raw_command)
{
return trace_probe_create(raw_command, __trace_uprobe_create);
}
static int create_or_delete_trace_uprobe(const char *raw_command)
{
int ret;
if (raw_command[0] == '-')
return dyn_event_release(raw_command, &trace_uprobe_ops);
ret = trace_uprobe_create(raw_command);
return ret == -ECANCELED ? -EINVAL : ret;
}
static int trace_uprobe_release(struct dyn_event *ev)
{
struct trace_uprobe *tu = to_trace_uprobe(ev);
return unregister_trace_uprobe(tu);
}
/* Probes listing interfaces */
static int trace_uprobe_show(struct seq_file *m, struct dyn_event *ev)
{
struct trace_uprobe *tu = to_trace_uprobe(ev);
char c = is_ret_probe(tu) ? 'r' : 'p';
int i;
seq_printf(m, "%c:%s/%s %s:0x%0*lx", c, trace_probe_group_name(&tu->tp),
trace_probe_name(&tu->tp), tu->filename,
(int)(sizeof(void *) * 2), tu->offset);
if (tu->ref_ctr_offset)
seq_printf(m, "(0x%lx)", tu->ref_ctr_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_putc(m, '\n');
return 0;
}
static int probes_seq_show(struct seq_file *m, void *v)
{
struct dyn_event *ev = v;
if (!is_trace_uprobe(ev))
return 0;
return trace_uprobe_show(m, ev);
}
static const struct seq_operations probes_seq_op = {
.start = dyn_event_seq_start,
.next = dyn_event_seq_next,
.stop = dyn_event_seq_stop,
.show = probes_seq_show
};
static int probes_open(struct inode *inode, struct file *file)
{
int ret;
ret = security_locked_down(LOCKDOWN_TRACEFS);
if (ret)
return ret;
if ((file->f_mode & FMODE_WRITE) && (file->f_flags & O_TRUNC)) {
ret = dyn_events_release_all(&trace_uprobe_ops);
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 trace_parse_run_command(file, buffer, count, ppos,
create_or_delete_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 dyn_event *ev = v;
struct trace_uprobe *tu;
if (!is_trace_uprobe(ev))
return 0;
tu = to_trace_uprobe(ev);
seq_printf(m, " %s %-44s %15lu\n", tu->filename,
trace_probe_name(&tu->tp), tu->nhit);
return 0;
}
static const struct seq_operations profile_seq_op = {
.start = dyn_event_seq_start,
.next = dyn_event_seq_next,
.stop = dyn_event_seq_stop,
.show = probes_profile_seq_show
};
static int profile_open(struct inode *inode, struct file *file)
{
int ret;
ret = security_locked_down(LOCKDOWN_TRACEFS);
if (ret)
return ret;
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,
};
struct uprobe_cpu_buffer {
struct mutex mutex;
void *buf;
int dsize;
};
static struct uprobe_cpu_buffer __percpu *uprobe_cpu_buffer;
static int uprobe_buffer_refcnt;
static int uprobe_buffer_init(void)
{
int cpu, err_cpu;
uprobe_cpu_buffer = alloc_percpu(struct uprobe_cpu_buffer);
if (uprobe_cpu_buffer == NULL)
return -ENOMEM;
for_each_possible_cpu(cpu) {
struct page *p = alloc_pages_node(cpu_to_node(cpu),
GFP_KERNEL, 0);
if (p == NULL) {
err_cpu = cpu;
goto err;
}
per_cpu_ptr(uprobe_cpu_buffer, cpu)->buf = page_address(p);
mutex_init(&per_cpu_ptr(uprobe_cpu_buffer, cpu)->mutex);
}
return 0;
err:
for_each_possible_cpu(cpu) {
if (cpu == err_cpu)
break;
free_page((unsigned long)per_cpu_ptr(uprobe_cpu_buffer, cpu)->buf);
}
free_percpu(uprobe_cpu_buffer);
return -ENOMEM;
}
static int uprobe_buffer_enable(void)
{
int ret = 0;
BUG_ON(!mutex_is_locked(&event_mutex));
if (uprobe_buffer_refcnt++ == 0) {
ret = uprobe_buffer_init();
if (ret < 0)
uprobe_buffer_refcnt--;
}
return ret;
}
static void uprobe_buffer_disable(void)
{
int cpu;
BUG_ON(!mutex_is_locked(&event_mutex));
if (--uprobe_buffer_refcnt == 0) {
for_each_possible_cpu(cpu)
free_page((unsigned long)per_cpu_ptr(uprobe_cpu_buffer,
cpu)->buf);
free_percpu(uprobe_cpu_buffer);
uprobe_cpu_buffer = NULL;
}
}
static struct uprobe_cpu_buffer *uprobe_buffer_get(void)
{
struct uprobe_cpu_buffer *ucb;
int cpu;
cpu = raw_smp_processor_id();
ucb = per_cpu_ptr(uprobe_cpu_buffer, cpu);
/*
* Use per-cpu buffers for fastest access, but we might migrate
* so the mutex makes sure we have sole access to it.
*/
mutex_lock(&ucb->mutex);
return ucb;
}
static void uprobe_buffer_put(struct uprobe_cpu_buffer *ucb)
{
if (!ucb)
return;
mutex_unlock(&ucb->mutex);
}
static struct uprobe_cpu_buffer *prepare_uprobe_buffer(struct trace_uprobe *tu,
struct pt_regs *regs,
struct uprobe_cpu_buffer **ucbp)
{
struct uprobe_cpu_buffer *ucb;
int dsize, esize;
if (*ucbp)
return *ucbp;
esize = SIZEOF_TRACE_ENTRY(is_ret_probe(tu));
dsize = __get_data_size(&tu->tp, regs, NULL);
ucb = uprobe_buffer_get();
ucb->dsize = tu->tp.size + dsize;
store_trace_args(ucb->buf, &tu->tp, regs, NULL, esize, dsize);
*ucbp = ucb;
return ucb;
}
static void __uprobe_trace_func(struct trace_uprobe *tu,
unsigned long func, struct pt_regs *regs,
struct uprobe_cpu_buffer *ucb,
struct trace_event_file *trace_file)
{
struct uprobe_trace_entry_head *entry;
struct trace_event_buffer fbuffer;
void *data;
int size, esize;
struct trace_event_call *call = trace_probe_event_call(&tu->tp);
WARN_ON(call != trace_file->event_call);
if (WARN_ON_ONCE(ucb->dsize > PAGE_SIZE))
return;
if (trace_trigger_soft_disabled(trace_file))
return;
esize = SIZEOF_TRACE_ENTRY(is_ret_probe(tu));
size = esize + ucb->dsize;
entry = trace_event_buffer_reserve(&fbuffer, trace_file, size);
if (!entry)
return;
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);
}
memcpy(data, ucb->buf, ucb->dsize);
trace_event_buffer_commit(&fbuffer);
}
/* uprobe handler */
static int uprobe_trace_func(struct trace_uprobe *tu, struct pt_regs *regs,
struct uprobe_cpu_buffer **ucbp)
{
struct event_file_link *link;
struct uprobe_cpu_buffer *ucb;
if (is_ret_probe(tu))
return 0;
ucb = prepare_uprobe_buffer(tu, regs, ucbp);
rcu_read_lock();
trace_probe_for_each_link_rcu(link, &tu->tp)
__uprobe_trace_func(tu, 0, regs, ucb, link->file);
rcu_read_unlock();
return 0;
}
static void uretprobe_trace_func(struct trace_uprobe *tu, unsigned long func,
struct pt_regs *regs,
struct uprobe_cpu_buffer **ucbp)
{
struct event_file_link *link;
struct uprobe_cpu_buffer *ucb;
ucb = prepare_uprobe_buffer(tu, regs, ucbp);
rcu_read_lock();
trace_probe_for_each_link_rcu(link, &tu->tp)
__uprobe_trace_func(tu, func, regs, ucb, link->file);
rcu_read_unlock();
}
/* 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;
entry = (struct uprobe_trace_entry_head *)iter->ent;
tu = trace_uprobe_primary_from_call(
container_of(event, struct trace_event_call, event));
if (unlikely(!tu))
goto out;
if (is_ret_probe(tu)) {
trace_seq_printf(s, "%s: (0x%lx <- 0x%lx)",
trace_probe_name(&tu->tp),
entry->vaddr[1], entry->vaddr[0]);
data = DATAOF_TRACE_ENTRY(entry, true);
} else {
trace_seq_printf(s, "%s: (0x%lx)",
trace_probe_name(&tu->tp),
entry->vaddr[0]);
data = DATAOF_TRACE_ENTRY(entry, false);
}
if (trace_probe_print_args(s, tu->tp.args, tu->tp.nr_args, data, entry) < 0)
goto out;
trace_seq_putc(s, '\n');
out:
return trace_handle_return(s);
}
typedef bool (*filter_func_t)(struct uprobe_consumer *self,
enum uprobe_filter_ctx ctx,
struct mm_struct *mm);
static int trace_uprobe_enable(struct trace_uprobe *tu, filter_func_t filter)
{
int ret;
tu->consumer.filter = filter;
tu->inode = d_real_inode(tu->path.dentry);
if (tu->ref_ctr_offset)
ret = uprobe_register_refctr(tu->inode, tu->offset,
tu->ref_ctr_offset, &tu->consumer);
else
ret = uprobe_register(tu->inode, tu->offset, &tu->consumer);
if (ret)
tu->inode = NULL;
return ret;
}
static void __probe_event_disable(struct trace_probe *tp)
{
struct trace_uprobe *tu;
tu = container_of(tp, struct trace_uprobe, tp);
WARN_ON(!uprobe_filter_is_empty(tu->tp.event->filter));
list_for_each_entry(tu, trace_probe_probe_list(tp), tp.list) {
if (!tu->inode)
continue;
uprobe_unregister(tu->inode, tu->offset, &tu->consumer);
tu->inode = NULL;
}
}
static int probe_event_enable(struct trace_event_call *call,
struct trace_event_file *file, filter_func_t filter)
{
struct trace_probe *tp;
struct trace_uprobe *tu;
bool enabled;
int ret;
tp = trace_probe_primary_from_call(call);
if (WARN_ON_ONCE(!tp))
return -ENODEV;
enabled = trace_probe_is_enabled(tp);
/* This may also change "enabled" state */
if (file) {
if (trace_probe_test_flag(tp, TP_FLAG_PROFILE))
return -EINTR;
ret = trace_probe_add_file(tp, file);
if (ret < 0)
return ret;
} else {
if (trace_probe_test_flag(tp, TP_FLAG_TRACE))
return -EINTR;
trace_probe_set_flag(tp, TP_FLAG_PROFILE);
}
tu = container_of(tp, struct trace_uprobe, tp);
WARN_ON(!uprobe_filter_is_empty(tu->tp.event->filter));
if (enabled)
return 0;
ret = uprobe_buffer_enable();
if (ret)
goto err_flags;
list_for_each_entry(tu, trace_probe_probe_list(tp), tp.list) {
ret = trace_uprobe_enable(tu, filter);
if (ret) {
__probe_event_disable(tp);
goto err_buffer;
}
}
return 0;
err_buffer:
uprobe_buffer_disable();
err_flags:
if (file)
trace_probe_remove_file(tp, file);
else
trace_probe_clear_flag(tp, TP_FLAG_PROFILE);
return ret;
}
static void probe_event_disable(struct trace_event_call *call,
struct trace_event_file *file)
{
struct trace_probe *tp;
tp = trace_probe_primary_from_call(call);
if (WARN_ON_ONCE(!tp))
return;
if (!trace_probe_is_enabled(tp))
return;
if (file) {
if (trace_probe_remove_file(tp, file) < 0)
return;
if (trace_probe_is_enabled(tp))
return;
} else
trace_probe_clear_flag(tp, TP_FLAG_PROFILE);
__probe_event_disable(tp);
uprobe_buffer_disable();
}
static int uprobe_event_define_fields(struct trace_event_call *event_call)
{
int ret, size;
struct uprobe_trace_entry_head field;
struct trace_uprobe *tu;
tu = trace_uprobe_primary_from_call(event_call);
if (unlikely(!tu))
return -ENODEV;
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);
}
return traceprobe_define_arg_fields(event_call, size, &tu->tp);
}
#ifdef CONFIG_PERF_EVENTS
static bool
__uprobe_perf_filter(struct trace_uprobe_filter *filter, struct mm_struct *mm)
{
struct perf_event *event;
list_for_each_entry(event, &filter->perf_events, hw.tp_list) {
if (event->hw.target->mm == mm)
return true;
}
return false;
}
static inline bool
trace_uprobe_filter_event(struct trace_uprobe_filter *filter,
struct perf_event *event)
{
return __uprobe_perf_filter(filter, event->hw.target->mm);
}
static bool trace_uprobe_filter_remove(struct trace_uprobe_filter *filter,
struct perf_event *event)
{
bool done;
write_lock(&filter->rwlock);
if (event->hw.target) {
list_del(&event->hw.tp_list);
done = filter->nr_systemwide ||
(event->hw.target->flags & PF_EXITING) ||
trace_uprobe_filter_event(filter, event);
} else {
filter->nr_systemwide--;
done = filter->nr_systemwide;
}
write_unlock(&filter->rwlock);
return done;
}
/* This returns true if the filter always covers target mm */
static bool trace_uprobe_filter_add(struct trace_uprobe_filter *filter,
struct perf_event *event)
{
bool done;
write_lock(&filter->rwlock);
if (event->hw.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 = filter->nr_systemwide ||
event->parent || event->attr.enable_on_exec ||
trace_uprobe_filter_event(filter, event);
list_add(&event->hw.tp_list, &filter->perf_events);
} else {
done = filter->nr_systemwide;
filter->nr_systemwide++;
}
write_unlock(&filter->rwlock);
return done;
}
static int uprobe_perf_close(struct trace_event_call *call,
struct perf_event *event)
{
struct trace_probe *tp;
struct trace_uprobe *tu;
int ret = 0;
tp = trace_probe_primary_from_call(call);
if (WARN_ON_ONCE(!tp))
return -ENODEV;
tu = container_of(tp, struct trace_uprobe, tp);
if (trace_uprobe_filter_remove(tu->tp.event->filter, event))
return 0;
list_for_each_entry(tu, trace_probe_probe_list(tp), tp.list) {
ret = uprobe_apply(tu->inode, tu->offset, &tu->consumer, false);
if (ret)
break;
}
return ret;
}
static int uprobe_perf_open(struct trace_event_call *call,
struct perf_event *event)
{
struct trace_probe *tp;
struct trace_uprobe *tu;
int err = 0;
tp = trace_probe_primary_from_call(call);
if (WARN_ON_ONCE(!tp))
return -ENODEV;
tu = container_of(tp, struct trace_uprobe, tp);
if (trace_uprobe_filter_add(tu->tp.event->filter, event))
return 0;
list_for_each_entry(tu, trace_probe_probe_list(tp), tp.list) {
err = uprobe_apply(tu->inode, tu->offset, &tu->consumer, true);
if (err) {
uprobe_perf_close(call, event);
break;
}
}
return err;
}
static bool uprobe_perf_filter(struct uprobe_consumer *uc,
enum uprobe_filter_ctx ctx, struct mm_struct *mm)
{
struct trace_uprobe_filter *filter;
struct trace_uprobe *tu;
int ret;
tu = container_of(uc, struct trace_uprobe, consumer);
filter = tu->tp.event->filter;
/*
* speculative short-circuiting check to avoid unnecessarily taking
* filter->rwlock below, if the uprobe has system-wide consumer
*/
if (READ_ONCE(filter->nr_systemwide))
return true;
read_lock(&filter->rwlock);
ret = __uprobe_perf_filter(filter, mm);
read_unlock(&filter->rwlock);
return ret;
}
static void __uprobe_perf_func(struct trace_uprobe *tu,
unsigned long func, struct pt_regs *regs,
struct uprobe_cpu_buffer **ucbp)
{
struct trace_event_call *call = trace_probe_event_call(&tu->tp);
struct uprobe_trace_entry_head *entry;
struct uprobe_cpu_buffer *ucb;
struct hlist_head *head;
void *data;
int size, esize;
int rctx;
#ifdef CONFIG_BPF_EVENTS
if (bpf_prog_array_valid(call)) {
u32 ret;
ret = bpf_prog_run_array_uprobe(call->prog_array, regs, bpf_prog_run);
if (!ret)
return;
}
#endif /* CONFIG_BPF_EVENTS */
esize = SIZEOF_TRACE_ENTRY(is_ret_probe(tu));
ucb = prepare_uprobe_buffer(tu, regs, ucbp);
size = esize + ucb->dsize;
size = ALIGN(size + sizeof(u32), sizeof(u64)) - sizeof(u32);
if (WARN_ONCE(size > PERF_MAX_TRACE_SIZE, "profile buffer not large enough"))
return;
preempt_disable();
head = this_cpu_ptr(call->perf_events);
if (hlist_empty(head))
goto out;
entry = perf_trace_buf_alloc(size, NULL, &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);
}
memcpy(data, ucb->buf, ucb->dsize);
if (size - esize > ucb->dsize)
memset(data + ucb->dsize, 0, size - esize - ucb->dsize);
perf_trace_buf_submit(entry, size, rctx, call->event.type, 1, regs,
head, NULL);
out:
preempt_enable();
}
/* uprobe profile handler */
static int uprobe_perf_func(struct trace_uprobe *tu, struct pt_regs *regs,
struct uprobe_cpu_buffer **ucbp)
{
if (!uprobe_perf_filter(&tu->consumer, 0, current->mm))
return UPROBE_HANDLER_REMOVE;
if (!is_ret_probe(tu))
__uprobe_perf_func(tu, 0, regs, ucbp);
return 0;
}
static void uretprobe_perf_func(struct trace_uprobe *tu, unsigned long func,
struct pt_regs *regs,
struct uprobe_cpu_buffer **ucbp)
{
__uprobe_perf_func(tu, func, regs, ucbp);
}
int bpf_get_uprobe_info(const struct perf_event *event, u32 *fd_type,
const char **filename, u64 *probe_offset,
u64 *probe_addr, bool perf_type_tracepoint)
{
const char *pevent = trace_event_name(event->tp_event);
const char *group = event->tp_event->class->system;
struct trace_uprobe *tu;
if (perf_type_tracepoint)
tu = find_probe_event(pevent, group);
else
tu = trace_uprobe_primary_from_call(event->tp_event);
if (!tu)
return -EINVAL;
*fd_type = is_ret_probe(tu) ? BPF_FD_TYPE_URETPROBE
: BPF_FD_TYPE_UPROBE;
*filename = tu->filename;
*probe_offset = tu->offset;
*probe_addr = 0;
return 0;
}
#endif /* CONFIG_PERF_EVENTS */
static int
trace_uprobe_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 probe_event_enable(event, file, NULL);
case TRACE_REG_UNREGISTER:
probe_event_disable(event, file);
return 0;
#ifdef CONFIG_PERF_EVENTS
case TRACE_REG_PERF_REGISTER:
return probe_event_enable(event, NULL, uprobe_perf_filter);
case TRACE_REG_PERF_UNREGISTER:
probe_event_disable(event, NULL);
return 0;
case TRACE_REG_PERF_OPEN:
return uprobe_perf_open(event, data);
case TRACE_REG_PERF_CLOSE:
return uprobe_perf_close(event, data);
#endif
default:
return 0;
}
}
static int uprobe_dispatcher(struct uprobe_consumer *con, struct pt_regs *regs)
{
struct trace_uprobe *tu;
struct uprobe_dispatch_data udd;
struct uprobe_cpu_buffer *ucb = NULL;
int ret = 0;
tu = container_of(con, struct trace_uprobe, consumer);
tu->nhit++;
udd.tu = tu;
udd.bp_addr = instruction_pointer(regs);
current->utask->vaddr = (unsigned long) &udd;
if (WARN_ON_ONCE(!uprobe_cpu_buffer))
return 0;
if (trace_probe_test_flag(&tu->tp, TP_FLAG_TRACE))
ret |= uprobe_trace_func(tu, regs, &ucb);
#ifdef CONFIG_PERF_EVENTS
if (trace_probe_test_flag(&tu->tp, TP_FLAG_PROFILE))
ret |= uprobe_perf_func(tu, regs, &ucb);
#endif
uprobe_buffer_put(ucb);
return ret;
}
static int uretprobe_dispatcher(struct uprobe_consumer *con,
unsigned long func, struct pt_regs *regs)
{
struct trace_uprobe *tu;
struct uprobe_dispatch_data udd;
struct uprobe_cpu_buffer *ucb = NULL;
tu = container_of(con, struct trace_uprobe, consumer);
udd.tu = tu;
udd.bp_addr = func;
current->utask->vaddr = (unsigned long) &udd;
if (WARN_ON_ONCE(!uprobe_cpu_buffer))
return 0;
if (trace_probe_test_flag(&tu->tp, TP_FLAG_TRACE))
uretprobe_trace_func(tu, func, regs, &ucb);
#ifdef CONFIG_PERF_EVENTS
if (trace_probe_test_flag(&tu->tp, TP_FLAG_PROFILE))
uretprobe_perf_func(tu, func, regs, &ucb);
#endif
uprobe_buffer_put(ucb);
return 0;
}
static struct trace_event_functions uprobe_funcs = {
.trace = print_uprobe_event
};
static struct trace_event_fields uprobe_fields_array[] = {
{ .type = TRACE_FUNCTION_TYPE,
.define_fields = uprobe_event_define_fields },
{}
};
static inline void init_trace_event_call(struct trace_uprobe *tu)
{
struct trace_event_call *call = trace_probe_event_call(&tu->tp);
call->event.funcs = &uprobe_funcs;
call->class->fields_array = uprobe_fields_array;
call->flags = TRACE_EVENT_FL_UPROBE | TRACE_EVENT_FL_CAP_ANY;
call->class->reg = trace_uprobe_register;
}
static int register_uprobe_event(struct trace_uprobe *tu)
{
init_trace_event_call(tu);
return trace_probe_register_event_call(&tu->tp);
}
static int unregister_uprobe_event(struct trace_uprobe *tu)
{
return trace_probe_unregister_event_call(&tu->tp);
}
#ifdef CONFIG_PERF_EVENTS
struct trace_event_call *
create_local_trace_uprobe(char *name, unsigned long offs,
unsigned long ref_ctr_offset, bool is_return)
{
enum probe_print_type ptype;
struct trace_uprobe *tu;
struct path path;
int ret;
ret = kern_path(name, LOOKUP_FOLLOW, &path);
if (ret)
return ERR_PTR(ret);
if (!d_is_reg(path.dentry)) {
path_put(&path);
return ERR_PTR(-EINVAL);
}
/*
* local trace_kprobes are not added to dyn_event, so they are never
* searched in find_trace_kprobe(). Therefore, there is no concern of
* duplicated name "DUMMY_EVENT" here.
*/
tu = alloc_trace_uprobe(UPROBE_EVENT_SYSTEM, "DUMMY_EVENT", 0,
is_return);
if (IS_ERR(tu)) {
pr_info("Failed to allocate trace_uprobe.(%d)\n",
(int)PTR_ERR(tu));
path_put(&path);
return ERR_CAST(tu);
}
tu->offset = offs;
tu->path = path;
tu->ref_ctr_offset = ref_ctr_offset;
tu->filename = kstrdup(name, GFP_KERNEL);
if (!tu->filename) {
ret = -ENOMEM;
goto error;
}
init_trace_event_call(tu);
ptype = is_ret_probe(tu) ? PROBE_PRINT_RETURN : PROBE_PRINT_NORMAL;
if (traceprobe_set_print_fmt(&tu->tp, ptype) < 0) {
ret = -ENOMEM;
goto error;
}
return trace_probe_event_call(&tu->tp);
error:
free_trace_uprobe(tu);
return ERR_PTR(ret);
}
void destroy_local_trace_uprobe(struct trace_event_call *event_call)
{
struct trace_uprobe *tu;
tu = trace_uprobe_primary_from_call(event_call);
free_trace_uprobe(tu);
}
#endif /* CONFIG_PERF_EVENTS */
/* Make a trace interface for controlling probe points */
static __init int init_uprobe_trace(void)
{
int ret;
ret = dyn_event_register(&trace_uprobe_ops);
if (ret)
return ret;
ret = tracing_init_dentry();
if (ret)
return 0;
trace_create_file("uprobe_events", TRACE_MODE_WRITE, NULL,
NULL, &uprobe_events_ops);
/* Profile interface */
trace_create_file("uprobe_profile", TRACE_MODE_READ, NULL,
NULL, &uprobe_profile_ops);
return 0;
}
fs_initcall(init_uprobe_trace);