mirror of
https://github.com/AuxXxilium/linux_dsm_epyc7002.git
synced 2024-12-19 22:36:49 +07:00
02f4e01ce7
gcc produces a variable may be uninitialized warning for "val" in
parse_entry(). This is really a false positive, but the code is subtle
enough to just initialize val to zero and it's not a fast path to worry
about it.
Marked for stable to remove the warning in the stable trees as well.
Cc: stable@vger.kernel.org
Fixes: 6c3edaf9fd
("tracing: Introduce trace event injection")
Reported-by: kbuild test robot <lkp@intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
330 lines
6.4 KiB
C
330 lines
6.4 KiB
C
// SPDX-License-Identifier: GPL-2.0
|
|
/*
|
|
* trace_events_inject - trace event injection
|
|
*
|
|
* Copyright (C) 2019 Cong Wang <cwang@twitter.com>
|
|
*/
|
|
|
|
#include <linux/module.h>
|
|
#include <linux/ctype.h>
|
|
#include <linux/mutex.h>
|
|
#include <linux/slab.h>
|
|
#include <linux/rculist.h>
|
|
|
|
#include "trace.h"
|
|
|
|
static int
|
|
trace_inject_entry(struct trace_event_file *file, void *rec, int len)
|
|
{
|
|
struct trace_event_buffer fbuffer;
|
|
int written = 0;
|
|
void *entry;
|
|
|
|
rcu_read_lock_sched();
|
|
entry = trace_event_buffer_reserve(&fbuffer, file, len);
|
|
if (entry) {
|
|
memcpy(entry, rec, len);
|
|
written = len;
|
|
trace_event_buffer_commit(&fbuffer);
|
|
}
|
|
rcu_read_unlock_sched();
|
|
|
|
return written;
|
|
}
|
|
|
|
static int
|
|
parse_field(char *str, struct trace_event_call *call,
|
|
struct ftrace_event_field **pf, u64 *pv)
|
|
{
|
|
struct ftrace_event_field *field;
|
|
char *field_name;
|
|
int s, i = 0;
|
|
int len;
|
|
u64 val;
|
|
|
|
if (!str[i])
|
|
return 0;
|
|
/* First find the field to associate to */
|
|
while (isspace(str[i]))
|
|
i++;
|
|
s = i;
|
|
while (isalnum(str[i]) || str[i] == '_')
|
|
i++;
|
|
len = i - s;
|
|
if (!len)
|
|
return -EINVAL;
|
|
|
|
field_name = kmemdup_nul(str + s, len, GFP_KERNEL);
|
|
if (!field_name)
|
|
return -ENOMEM;
|
|
field = trace_find_event_field(call, field_name);
|
|
kfree(field_name);
|
|
if (!field)
|
|
return -ENOENT;
|
|
|
|
*pf = field;
|
|
while (isspace(str[i]))
|
|
i++;
|
|
if (str[i] != '=')
|
|
return -EINVAL;
|
|
i++;
|
|
while (isspace(str[i]))
|
|
i++;
|
|
s = i;
|
|
if (isdigit(str[i]) || str[i] == '-') {
|
|
char *num, c;
|
|
int ret;
|
|
|
|
/* Make sure the field is not a string */
|
|
if (is_string_field(field))
|
|
return -EINVAL;
|
|
|
|
if (str[i] == '-')
|
|
i++;
|
|
|
|
/* We allow 0xDEADBEEF */
|
|
while (isalnum(str[i]))
|
|
i++;
|
|
num = str + s;
|
|
c = str[i];
|
|
if (c != '\0' && !isspace(c))
|
|
return -EINVAL;
|
|
str[i] = '\0';
|
|
/* Make sure it is a value */
|
|
if (field->is_signed)
|
|
ret = kstrtoll(num, 0, &val);
|
|
else
|
|
ret = kstrtoull(num, 0, &val);
|
|
str[i] = c;
|
|
if (ret)
|
|
return ret;
|
|
|
|
*pv = val;
|
|
return i;
|
|
} else if (str[i] == '\'' || str[i] == '"') {
|
|
char q = str[i];
|
|
|
|
/* Make sure the field is OK for strings */
|
|
if (!is_string_field(field))
|
|
return -EINVAL;
|
|
|
|
for (i++; str[i]; i++) {
|
|
if (str[i] == '\\' && str[i + 1]) {
|
|
i++;
|
|
continue;
|
|
}
|
|
if (str[i] == q)
|
|
break;
|
|
}
|
|
if (!str[i])
|
|
return -EINVAL;
|
|
|
|
/* Skip quotes */
|
|
s++;
|
|
len = i - s;
|
|
if (len >= MAX_FILTER_STR_VAL)
|
|
return -EINVAL;
|
|
|
|
*pv = (unsigned long)(str + s);
|
|
str[i] = 0;
|
|
/* go past the last quote */
|
|
i++;
|
|
return i;
|
|
}
|
|
|
|
return -EINVAL;
|
|
}
|
|
|
|
static int trace_get_entry_size(struct trace_event_call *call)
|
|
{
|
|
struct ftrace_event_field *field;
|
|
struct list_head *head;
|
|
int size = 0;
|
|
|
|
head = trace_get_fields(call);
|
|
list_for_each_entry(field, head, link) {
|
|
if (field->size + field->offset > size)
|
|
size = field->size + field->offset;
|
|
}
|
|
|
|
return size;
|
|
}
|
|
|
|
static void *trace_alloc_entry(struct trace_event_call *call, int *size)
|
|
{
|
|
int entry_size = trace_get_entry_size(call);
|
|
struct ftrace_event_field *field;
|
|
struct list_head *head;
|
|
void *entry = NULL;
|
|
|
|
/* We need an extra '\0' at the end. */
|
|
entry = kzalloc(entry_size + 1, GFP_KERNEL);
|
|
if (!entry)
|
|
return NULL;
|
|
|
|
head = trace_get_fields(call);
|
|
list_for_each_entry(field, head, link) {
|
|
if (!is_string_field(field))
|
|
continue;
|
|
if (field->filter_type == FILTER_STATIC_STRING)
|
|
continue;
|
|
if (field->filter_type == FILTER_DYN_STRING) {
|
|
u32 *str_item;
|
|
int str_loc = entry_size & 0xffff;
|
|
|
|
str_item = (u32 *)(entry + field->offset);
|
|
*str_item = str_loc; /* string length is 0. */
|
|
} else {
|
|
char **paddr;
|
|
|
|
paddr = (char **)(entry + field->offset);
|
|
*paddr = "";
|
|
}
|
|
}
|
|
|
|
*size = entry_size + 1;
|
|
return entry;
|
|
}
|
|
|
|
#define INJECT_STRING "STATIC STRING CAN NOT BE INJECTED"
|
|
|
|
/* Caller is responsible to free the *pentry. */
|
|
static int parse_entry(char *str, struct trace_event_call *call, void **pentry)
|
|
{
|
|
struct ftrace_event_field *field;
|
|
unsigned long irq_flags;
|
|
void *entry = NULL;
|
|
int entry_size;
|
|
u64 val = 0;
|
|
int len;
|
|
|
|
entry = trace_alloc_entry(call, &entry_size);
|
|
*pentry = entry;
|
|
if (!entry)
|
|
return -ENOMEM;
|
|
|
|
local_save_flags(irq_flags);
|
|
tracing_generic_entry_update(entry, call->event.type, irq_flags,
|
|
preempt_count());
|
|
|
|
while ((len = parse_field(str, call, &field, &val)) > 0) {
|
|
if (is_function_field(field))
|
|
return -EINVAL;
|
|
|
|
if (is_string_field(field)) {
|
|
char *addr = (char *)(unsigned long) val;
|
|
|
|
if (field->filter_type == FILTER_STATIC_STRING) {
|
|
strlcpy(entry + field->offset, addr, field->size);
|
|
} else if (field->filter_type == FILTER_DYN_STRING) {
|
|
int str_len = strlen(addr) + 1;
|
|
int str_loc = entry_size & 0xffff;
|
|
u32 *str_item;
|
|
|
|
entry_size += str_len;
|
|
*pentry = krealloc(entry, entry_size, GFP_KERNEL);
|
|
if (!*pentry) {
|
|
kfree(entry);
|
|
return -ENOMEM;
|
|
}
|
|
entry = *pentry;
|
|
|
|
strlcpy(entry + (entry_size - str_len), addr, str_len);
|
|
str_item = (u32 *)(entry + field->offset);
|
|
*str_item = (str_len << 16) | str_loc;
|
|
} else {
|
|
char **paddr;
|
|
|
|
paddr = (char **)(entry + field->offset);
|
|
*paddr = INJECT_STRING;
|
|
}
|
|
} else {
|
|
switch (field->size) {
|
|
case 1: {
|
|
u8 tmp = (u8) val;
|
|
|
|
memcpy(entry + field->offset, &tmp, 1);
|
|
break;
|
|
}
|
|
case 2: {
|
|
u16 tmp = (u16) val;
|
|
|
|
memcpy(entry + field->offset, &tmp, 2);
|
|
break;
|
|
}
|
|
case 4: {
|
|
u32 tmp = (u32) val;
|
|
|
|
memcpy(entry + field->offset, &tmp, 4);
|
|
break;
|
|
}
|
|
case 8:
|
|
memcpy(entry + field->offset, &val, 8);
|
|
break;
|
|
default:
|
|
return -EINVAL;
|
|
}
|
|
}
|
|
|
|
str += len;
|
|
}
|
|
|
|
if (len < 0)
|
|
return len;
|
|
|
|
return entry_size;
|
|
}
|
|
|
|
static ssize_t
|
|
event_inject_write(struct file *filp, const char __user *ubuf, size_t cnt,
|
|
loff_t *ppos)
|
|
{
|
|
struct trace_event_call *call;
|
|
struct trace_event_file *file;
|
|
int err = -ENODEV, size;
|
|
void *entry = NULL;
|
|
char *buf;
|
|
|
|
if (cnt >= PAGE_SIZE)
|
|
return -EINVAL;
|
|
|
|
buf = memdup_user_nul(ubuf, cnt);
|
|
if (IS_ERR(buf))
|
|
return PTR_ERR(buf);
|
|
strim(buf);
|
|
|
|
mutex_lock(&event_mutex);
|
|
file = event_file_data(filp);
|
|
if (file) {
|
|
call = file->event_call;
|
|
size = parse_entry(buf, call, &entry);
|
|
if (size < 0)
|
|
err = size;
|
|
else
|
|
err = trace_inject_entry(file, entry, size);
|
|
}
|
|
mutex_unlock(&event_mutex);
|
|
|
|
kfree(entry);
|
|
kfree(buf);
|
|
|
|
if (err < 0)
|
|
return err;
|
|
|
|
*ppos += err;
|
|
return cnt;
|
|
}
|
|
|
|
static ssize_t
|
|
event_inject_read(struct file *file, char __user *buf, size_t size,
|
|
loff_t *ppos)
|
|
{
|
|
return -EPERM;
|
|
}
|
|
|
|
const struct file_operations event_inject_fops = {
|
|
.open = tracing_open_generic,
|
|
.read = event_inject_read,
|
|
.write = event_inject_write,
|
|
};
|