mirror of
https://mirrors.bfsu.edu.cn/git/linux.git
synced 2024-12-24 11:34:50 +08:00
0722069a53
When printing multiple uprobe arguments as strings the output for the
earlier arguments would also include all later string arguments.
This is best explained in an example:
Consider adding a uprobe to a function receiving two strings as
parameters which is at offset 0xa0 in strlib.so and we want to print
both parameters when the uprobe is hit (on x86_64):
$ echo 'p:func /lib/strlib.so:0xa0 +0(%di):string +0(%si):string' > \
/sys/kernel/debug/tracing/uprobe_events
When the function is called as func("foo", "bar") and we hit the probe,
the trace file shows a line like the following:
[...] func: (0x7f7e683706a0) arg1="foobar" arg2="bar"
Note the extra "bar" printed as part of arg1. This behaviour stacks up
for additional string arguments.
The strings are stored in a dynamically growing part of the uprobe
buffer by fetch_store_string() after copying them from userspace via
strncpy_from_user(). The return value of strncpy_from_user() is then
directly used as the required size for the string. However, this does
not take the terminating null byte into account as the documentation
for strncpy_from_user() cleary states that it "[...] returns the
length of the string (not including the trailing NUL)" even though the
null byte will be copied to the destination.
Therefore, subsequent calls to fetch_store_string() will overwrite
the terminating null byte of the most recently fetched string with
the first character of the current string, leading to the
"accumulation" of strings in earlier arguments in the output.
Fix this by incrementing the return value of strncpy_from_user() by
one if we did not hit the maximum buffer size.
Link: http://lkml.kernel.org/r/20190116141629.5752-1-andreas.ziegler@fau.de
Cc: Ingo Molnar <mingo@redhat.com>
Cc: stable@vger.kernel.org
Fixes: 5baaa59ef0
("tracing/probes: Implement 'memory' fetch method for uprobes")
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Andreas Ziegler <andreas.ziegler@fau.de>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
1441 lines
33 KiB
C
1441 lines
33 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/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 "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))
|
|
|
|
struct trace_uprobe_filter {
|
|
rwlock_t rwlock;
|
|
int nr_systemwide;
|
|
struct list_head perf_events;
|
|
};
|
|
|
|
static int trace_uprobe_create(int argc, const char **argv);
|
|
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,
|
|
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 trace_uprobe_filter filter;
|
|
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)))
|
|
|
|
#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);
|
|
|
|
struct uprobe_dispatch_data {
|
|
struct trace_uprobe *tu;
|
|
unsigned long bp_addr;
|
|
};
|
|
|
|
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;
|
|
}
|
|
/*
|
|
* 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;
|
|
|
|
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);
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
|
|
/* 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;
|
|
|
|
len = strnlen_user(vaddr, MAX_STRING_SIZE);
|
|
|
|
return (len > MAX_STRING_SIZE) ? 0 : len;
|
|
}
|
|
|
|
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, struct pt_regs *regs, void *dest,
|
|
void *base)
|
|
{
|
|
unsigned long val;
|
|
|
|
/* 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_IMM:
|
|
val = code->immediate;
|
|
break;
|
|
case FETCH_OP_FOFFS:
|
|
val = translate_user_vaddr(code->immediate);
|
|
break;
|
|
default:
|
|
return -EILSEQ;
|
|
}
|
|
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(const char *system, const char *event,
|
|
struct dyn_event *ev)
|
|
{
|
|
struct trace_uprobe *tu = to_trace_uprobe(ev);
|
|
|
|
return strcmp(trace_event_name(&tu->tp.call), event) == 0 &&
|
|
(!system || strcmp(tu->tp.call.class->system, system) == 0);
|
|
}
|
|
|
|
/*
|
|
* 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;
|
|
|
|
dyn_event_init(&tu->devent, &trace_uprobe_ops);
|
|
INIT_LIST_HEAD(&tu->tp.files);
|
|
tu->consumer.handler = uprobe_dispatcher;
|
|
if (is_ret)
|
|
tu->consumer.ret_handler = uretprobe_dispatcher;
|
|
init_trace_uprobe_filter(&tu->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;
|
|
|
|
if (!tu)
|
|
return;
|
|
|
|
for (i = 0; i < tu->tp.nr_args; i++)
|
|
traceprobe_free_probe_arg(&tu->tp.args[i]);
|
|
|
|
path_put(&tu->path);
|
|
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 dyn_event *pos;
|
|
struct trace_uprobe *tu;
|
|
|
|
for_each_trace_uprobe(tu, pos)
|
|
if (strcmp(trace_event_name(&tu->tp.call), event) == 0 &&
|
|
strcmp(tu->tp.call.class->system, group) == 0)
|
|
return tu;
|
|
|
|
return NULL;
|
|
}
|
|
|
|
/* Unregister a trace_uprobe and probe_event */
|
|
static int unregister_trace_uprobe(struct trace_uprobe *tu)
|
|
{
|
|
int ret;
|
|
|
|
ret = unregister_uprobe_event(tu);
|
|
if (ret)
|
|
return ret;
|
|
|
|
dyn_event_remove(&tu->devent);
|
|
free_trace_uprobe(tu);
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* 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 struct trace_uprobe *find_old_trace_uprobe(struct trace_uprobe *new)
|
|
{
|
|
struct dyn_event *pos;
|
|
struct trace_uprobe *tmp, *old = NULL;
|
|
struct inode *new_inode = d_real_inode(new->path.dentry);
|
|
|
|
old = find_probe_event(trace_event_name(&new->tp.call),
|
|
new->tp.call.class->system);
|
|
|
|
for_each_trace_uprobe(tmp, pos) {
|
|
if ((old ? old != tmp : true) &&
|
|
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 ERR_PTR(-EINVAL);
|
|
}
|
|
}
|
|
return old;
|
|
}
|
|
|
|
/* 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);
|
|
|
|
/* register as an event */
|
|
old_tu = find_old_trace_uprobe(tu);
|
|
if (IS_ERR(old_tu)) {
|
|
ret = PTR_ERR(old_tu);
|
|
goto end;
|
|
}
|
|
|
|
if (old_tu) {
|
|
/* delete old event */
|
|
ret = unregister_trace_uprobe(old_tu);
|
|
if (ret)
|
|
goto end;
|
|
}
|
|
|
|
ret = register_uprobe_event(tu);
|
|
if (ret) {
|
|
pr_warn("Failed to register probe event(%d)\n", ret);
|
|
goto end;
|
|
}
|
|
|
|
dyn_event_add(&tu->devent);
|
|
|
|
end:
|
|
mutex_unlock(&event_mutex);
|
|
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* Argument syntax:
|
|
* - Add uprobe: p|r[:[GRP/]EVENT] PATH:OFFSET [FETCHARGS]
|
|
*
|
|
* - Remove uprobe: -:[GRP/]EVENT
|
|
*/
|
|
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];
|
|
struct path path;
|
|
unsigned long offset, ref_ctr_offset;
|
|
bool is_return = false;
|
|
int i, ret;
|
|
|
|
ret = 0;
|
|
ref_ctr_offset = 0;
|
|
|
|
/* argc must be >= 1 */
|
|
if (argv[0][0] == 'r')
|
|
is_return = true;
|
|
else if (argv[0][0] != 'p' || 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;
|
|
}
|
|
|
|
*arg++ = '\0';
|
|
ret = kern_path(filename, LOOKUP_FOLLOW, &path);
|
|
if (ret) {
|
|
kfree(filename);
|
|
return ret;
|
|
}
|
|
if (!d_is_reg(path.dentry)) {
|
|
ret = -EINVAL;
|
|
goto fail_address_parse;
|
|
}
|
|
|
|
/* Parse reference counter offset if specified. */
|
|
rctr = strchr(arg, '(');
|
|
if (rctr) {
|
|
rctr_end = strchr(rctr, ')');
|
|
if (rctr > rctr_end || *(rctr_end + 1) != 0) {
|
|
ret = -EINVAL;
|
|
pr_info("Invalid reference counter offset.\n");
|
|
goto fail_address_parse;
|
|
}
|
|
|
|
*rctr++ = '\0';
|
|
*rctr_end = '\0';
|
|
ret = kstrtoul(rctr, 0, &ref_ctr_offset);
|
|
if (ret) {
|
|
pr_info("Invalid reference counter offset.\n");
|
|
goto fail_address_parse;
|
|
}
|
|
}
|
|
|
|
/* Parse uprobe offset. */
|
|
ret = kstrtoul(arg, 0, &offset);
|
|
if (ret)
|
|
goto fail_address_parse;
|
|
|
|
argc -= 2;
|
|
argv += 2;
|
|
|
|
/* setup a probe */
|
|
if (event) {
|
|
ret = traceprobe_parse_event_name(&event, &group, buf);
|
|
if (ret)
|
|
goto fail_address_parse;
|
|
} else {
|
|
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->ref_ctr_offset = ref_ctr_offset;
|
|
tu->path = path;
|
|
tu->filename = filename;
|
|
|
|
/* parse arguments */
|
|
for (i = 0; i < argc && i < MAX_TRACE_ARGS; i++) {
|
|
tmp = kstrdup(argv[i], GFP_KERNEL);
|
|
if (!tmp) {
|
|
ret = -ENOMEM;
|
|
goto error;
|
|
}
|
|
|
|
ret = traceprobe_parse_probe_arg(&tu->tp, i, tmp,
|
|
is_return ? TPARG_FL_RETURN : 0);
|
|
kfree(tmp);
|
|
if (ret)
|
|
goto error;
|
|
}
|
|
|
|
ret = register_trace_uprobe(tu);
|
|
if (ret)
|
|
goto error;
|
|
return 0;
|
|
|
|
error:
|
|
free_trace_uprobe(tu);
|
|
return ret;
|
|
|
|
fail_address_parse:
|
|
path_put(&path);
|
|
kfree(filename);
|
|
|
|
pr_info("Failed to parse address or file.\n");
|
|
|
|
return ret;
|
|
}
|
|
|
|
static int create_or_delete_trace_uprobe(int argc, char **argv)
|
|
{
|
|
int ret;
|
|
|
|
if (argv[0][0] == '-')
|
|
return dyn_event_release(argc, argv, &trace_uprobe_ops);
|
|
|
|
ret = trace_uprobe_create(argc, (const char **)argv);
|
|
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, tu->tp.call.class->system,
|
|
trace_event_name(&tu->tp.call), 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;
|
|
|
|
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_event_name(&tu->tp.call), 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)
|
|
{
|
|
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;
|
|
};
|
|
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)
|
|
{
|
|
mutex_unlock(&ucb->mutex);
|
|
}
|
|
|
|
static void __uprobe_trace_func(struct trace_uprobe *tu,
|
|
unsigned long func, struct pt_regs *regs,
|
|
struct uprobe_cpu_buffer *ucb, int dsize,
|
|
struct trace_event_file *trace_file)
|
|
{
|
|
struct uprobe_trace_entry_head *entry;
|
|
struct ring_buffer_event *event;
|
|
struct ring_buffer *buffer;
|
|
void *data;
|
|
int size, esize;
|
|
struct trace_event_call *call = &tu->tp.call;
|
|
|
|
WARN_ON(call != trace_file->event_call);
|
|
|
|
if (WARN_ON_ONCE(tu->tp.size + dsize > PAGE_SIZE))
|
|
return;
|
|
|
|
if (trace_trigger_soft_disabled(trace_file))
|
|
return;
|
|
|
|
esize = SIZEOF_TRACE_ENTRY(is_ret_probe(tu));
|
|
size = esize + tu->tp.size + dsize;
|
|
event = trace_event_buffer_lock_reserve(&buffer, trace_file,
|
|
call->event.type, 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);
|
|
}
|
|
|
|
memcpy(data, ucb->buf, tu->tp.size + dsize);
|
|
|
|
event_trigger_unlock_commit(trace_file, buffer, event, entry, 0, 0);
|
|
}
|
|
|
|
/* uprobe handler */
|
|
static int uprobe_trace_func(struct trace_uprobe *tu, struct pt_regs *regs,
|
|
struct uprobe_cpu_buffer *ucb, int dsize)
|
|
{
|
|
struct event_file_link *link;
|
|
|
|
if (is_ret_probe(tu))
|
|
return 0;
|
|
|
|
rcu_read_lock();
|
|
list_for_each_entry_rcu(link, &tu->tp.files, list)
|
|
__uprobe_trace_func(tu, 0, regs, ucb, dsize, 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 *ucb, int dsize)
|
|
{
|
|
struct event_file_link *link;
|
|
|
|
rcu_read_lock();
|
|
list_for_each_entry_rcu(link, &tu->tp.files, list)
|
|
__uprobe_trace_func(tu, func, regs, ucb, dsize, 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 = container_of(event, struct trace_uprobe, tp.call.event);
|
|
|
|
if (is_ret_probe(tu)) {
|
|
trace_seq_printf(s, "%s: (0x%lx <- 0x%lx)",
|
|
trace_event_name(&tu->tp.call),
|
|
entry->vaddr[1], entry->vaddr[0]);
|
|
data = DATAOF_TRACE_ENTRY(entry, true);
|
|
} else {
|
|
trace_seq_printf(s, "%s: (0x%lx)",
|
|
trace_event_name(&tu->tp.call),
|
|
entry->vaddr[0]);
|
|
data = DATAOF_TRACE_ENTRY(entry, false);
|
|
}
|
|
|
|
if (print_probe_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
|
|
probe_event_enable(struct trace_uprobe *tu, struct trace_event_file *file,
|
|
filter_func_t filter)
|
|
{
|
|
bool enabled = trace_probe_is_enabled(&tu->tp);
|
|
struct event_file_link *link = NULL;
|
|
int ret;
|
|
|
|
if (file) {
|
|
if (tu->tp.flags & TP_FLAG_PROFILE)
|
|
return -EINTR;
|
|
|
|
link = kmalloc(sizeof(*link), GFP_KERNEL);
|
|
if (!link)
|
|
return -ENOMEM;
|
|
|
|
link->file = file;
|
|
list_add_tail_rcu(&link->list, &tu->tp.files);
|
|
|
|
tu->tp.flags |= TP_FLAG_TRACE;
|
|
} else {
|
|
if (tu->tp.flags & TP_FLAG_TRACE)
|
|
return -EINTR;
|
|
|
|
tu->tp.flags |= TP_FLAG_PROFILE;
|
|
}
|
|
|
|
WARN_ON(!uprobe_filter_is_empty(&tu->filter));
|
|
|
|
if (enabled)
|
|
return 0;
|
|
|
|
ret = uprobe_buffer_enable();
|
|
if (ret)
|
|
goto err_flags;
|
|
|
|
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)
|
|
goto err_buffer;
|
|
|
|
return 0;
|
|
|
|
err_buffer:
|
|
uprobe_buffer_disable();
|
|
|
|
err_flags:
|
|
if (file) {
|
|
list_del(&link->list);
|
|
kfree(link);
|
|
tu->tp.flags &= ~TP_FLAG_TRACE;
|
|
} else {
|
|
tu->tp.flags &= ~TP_FLAG_PROFILE;
|
|
}
|
|
return ret;
|
|
}
|
|
|
|
static void
|
|
probe_event_disable(struct trace_uprobe *tu, struct trace_event_file *file)
|
|
{
|
|
if (!trace_probe_is_enabled(&tu->tp))
|
|
return;
|
|
|
|
if (file) {
|
|
struct event_file_link *link;
|
|
|
|
link = find_event_file_link(&tu->tp, file);
|
|
if (!link)
|
|
return;
|
|
|
|
list_del_rcu(&link->list);
|
|
/* synchronize with u{,ret}probe_trace_func */
|
|
synchronize_rcu();
|
|
kfree(link);
|
|
|
|
if (!list_empty(&tu->tp.files))
|
|
return;
|
|
}
|
|
|
|
WARN_ON(!uprobe_filter_is_empty(&tu->filter));
|
|
|
|
uprobe_unregister(tu->inode, tu->offset, &tu->consumer);
|
|
tu->inode = NULL;
|
|
tu->tp.flags &= file ? ~TP_FLAG_TRACE : ~TP_FLAG_PROFILE;
|
|
|
|
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 = 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);
|
|
}
|
|
|
|
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;
|
|
|
|
if (filter->nr_systemwide)
|
|
return true;
|
|
|
|
list_for_each_entry(event, &filter->perf_events, hw.tp_list) {
|
|
if (event->hw.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.target->mm);
|
|
}
|
|
|
|
static int uprobe_perf_close(struct trace_uprobe *tu, struct perf_event *event)
|
|
{
|
|
bool done;
|
|
|
|
write_lock(&tu->filter.rwlock);
|
|
if (event->hw.target) {
|
|
list_del(&event->hw.tp_list);
|
|
done = tu->filter.nr_systemwide ||
|
|
(event->hw.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)
|
|
return uprobe_apply(tu->inode, tu->offset, &tu->consumer, false);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int uprobe_perf_open(struct trace_uprobe *tu, struct perf_event *event)
|
|
{
|
|
bool done;
|
|
int err;
|
|
|
|
write_lock(&tu->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 = 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);
|
|
|
|
err = 0;
|
|
if (!done) {
|
|
err = uprobe_apply(tu->inode, tu->offset, &tu->consumer, true);
|
|
if (err)
|
|
uprobe_perf_close(tu, event);
|
|
}
|
|
return err;
|
|
}
|
|
|
|
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_func(struct trace_uprobe *tu,
|
|
unsigned long func, struct pt_regs *regs,
|
|
struct uprobe_cpu_buffer *ucb, int dsize)
|
|
{
|
|
struct trace_event_call *call = &tu->tp.call;
|
|
struct uprobe_trace_entry_head *entry;
|
|
struct hlist_head *head;
|
|
void *data;
|
|
int size, esize;
|
|
int rctx;
|
|
|
|
if (bpf_prog_array_valid(call) && !trace_call_bpf(call, regs))
|
|
return;
|
|
|
|
esize = SIZEOF_TRACE_ENTRY(is_ret_probe(tu));
|
|
|
|
size = esize + tu->tp.size + 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, tu->tp.size + dsize);
|
|
|
|
if (size - esize > tu->tp.size + dsize) {
|
|
int len = tu->tp.size + dsize;
|
|
|
|
memset(data + len, 0, size - esize - len);
|
|
}
|
|
|
|
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 *ucb, int dsize)
|
|
{
|
|
if (!uprobe_perf_filter(&tu->consumer, 0, current->mm))
|
|
return UPROBE_HANDLER_REMOVE;
|
|
|
|
if (!is_ret_probe(tu))
|
|
__uprobe_perf_func(tu, 0, regs, ucb, dsize);
|
|
return 0;
|
|
}
|
|
|
|
static void uretprobe_perf_func(struct trace_uprobe *tu, unsigned long func,
|
|
struct pt_regs *regs,
|
|
struct uprobe_cpu_buffer *ucb, int dsize)
|
|
{
|
|
__uprobe_perf_func(tu, func, regs, ucb, dsize);
|
|
}
|
|
|
|
int bpf_get_uprobe_info(const struct perf_event *event, u32 *fd_type,
|
|
const char **filename, u64 *probe_offset,
|
|
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 = event->tp_event->data;
|
|
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;
|
|
return 0;
|
|
}
|
|
#endif /* CONFIG_PERF_EVENTS */
|
|
|
|
static int
|
|
trace_uprobe_register(struct trace_event_call *event, enum trace_reg type,
|
|
void *data)
|
|
{
|
|
struct trace_uprobe *tu = event->data;
|
|
struct trace_event_file *file = data;
|
|
|
|
switch (type) {
|
|
case TRACE_REG_REGISTER:
|
|
return probe_event_enable(tu, file, NULL);
|
|
|
|
case TRACE_REG_UNREGISTER:
|
|
probe_event_disable(tu, file);
|
|
return 0;
|
|
|
|
#ifdef CONFIG_PERF_EVENTS
|
|
case TRACE_REG_PERF_REGISTER:
|
|
return probe_event_enable(tu, NULL, uprobe_perf_filter);
|
|
|
|
case TRACE_REG_PERF_UNREGISTER:
|
|
probe_event_disable(tu, NULL);
|
|
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;
|
|
struct uprobe_dispatch_data udd;
|
|
struct uprobe_cpu_buffer *ucb;
|
|
int dsize, esize;
|
|
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;
|
|
|
|
dsize = __get_data_size(&tu->tp, regs);
|
|
esize = SIZEOF_TRACE_ENTRY(is_ret_probe(tu));
|
|
|
|
ucb = uprobe_buffer_get();
|
|
store_trace_args(ucb->buf, &tu->tp, regs, esize, dsize);
|
|
|
|
if (tu->tp.flags & TP_FLAG_TRACE)
|
|
ret |= uprobe_trace_func(tu, regs, ucb, dsize);
|
|
|
|
#ifdef CONFIG_PERF_EVENTS
|
|
if (tu->tp.flags & TP_FLAG_PROFILE)
|
|
ret |= uprobe_perf_func(tu, regs, ucb, dsize);
|
|
#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;
|
|
int dsize, esize;
|
|
|
|
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;
|
|
|
|
dsize = __get_data_size(&tu->tp, regs);
|
|
esize = SIZEOF_TRACE_ENTRY(is_ret_probe(tu));
|
|
|
|
ucb = uprobe_buffer_get();
|
|
store_trace_args(ucb->buf, &tu->tp, regs, esize, dsize);
|
|
|
|
if (tu->tp.flags & TP_FLAG_TRACE)
|
|
uretprobe_trace_func(tu, func, regs, ucb, dsize);
|
|
|
|
#ifdef CONFIG_PERF_EVENTS
|
|
if (tu->tp.flags & TP_FLAG_PROFILE)
|
|
uretprobe_perf_func(tu, func, regs, ucb, dsize);
|
|
#endif
|
|
uprobe_buffer_put(ucb);
|
|
return 0;
|
|
}
|
|
|
|
static struct trace_event_functions uprobe_funcs = {
|
|
.trace = print_uprobe_event
|
|
};
|
|
|
|
static inline void init_trace_event_call(struct trace_uprobe *tu,
|
|
struct trace_event_call *call)
|
|
{
|
|
INIT_LIST_HEAD(&call->class->fields);
|
|
call->event.funcs = &uprobe_funcs;
|
|
call->class->define_fields = uprobe_event_define_fields;
|
|
|
|
call->flags = TRACE_EVENT_FL_UPROBE;
|
|
call->class->reg = trace_uprobe_register;
|
|
call->data = tu;
|
|
}
|
|
|
|
static int register_uprobe_event(struct trace_uprobe *tu)
|
|
{
|
|
struct trace_event_call *call = &tu->tp.call;
|
|
int ret = 0;
|
|
|
|
init_trace_event_call(tu, call);
|
|
|
|
if (traceprobe_set_print_fmt(&tu->tp, is_ret_probe(tu)) < 0)
|
|
return -ENOMEM;
|
|
|
|
ret = register_trace_event(&call->event);
|
|
if (!ret) {
|
|
kfree(call->print_fmt);
|
|
return -ENODEV;
|
|
}
|
|
|
|
ret = trace_add_event_call(call);
|
|
|
|
if (ret) {
|
|
pr_info("Failed to register uprobe event: %s\n",
|
|
trace_event_name(call));
|
|
kfree(call->print_fmt);
|
|
unregister_trace_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;
|
|
}
|
|
|
|
#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)
|
|
{
|
|
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);
|
|
init_trace_event_call(tu, &tu->tp.call);
|
|
|
|
if (traceprobe_set_print_fmt(&tu->tp, is_ret_probe(tu)) < 0) {
|
|
ret = -ENOMEM;
|
|
goto error;
|
|
}
|
|
|
|
return &tu->tp.call;
|
|
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 = container_of(event_call, struct trace_uprobe, tp.call);
|
|
|
|
kfree(tu->tp.call.print_fmt);
|
|
tu->tp.call.print_fmt = NULL;
|
|
|
|
free_trace_uprobe(tu);
|
|
}
|
|
#endif /* CONFIG_PERF_EVENTS */
|
|
|
|
/* Make a trace interface for controling probe points */
|
|
static __init int init_uprobe_trace(void)
|
|
{
|
|
struct dentry *d_tracer;
|
|
int ret;
|
|
|
|
ret = dyn_event_register(&trace_uprobe_ops);
|
|
if (ret)
|
|
return ret;
|
|
|
|
d_tracer = tracing_init_dentry();
|
|
if (IS_ERR(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);
|