Commit c7c6b1fe authored by Li Zefan's avatar Li Zefan Committed by Steven Rostedt
Browse files

ftrace: Allow to remove a single function from function graph filter



I don't see why we can only clear all functions from the filter.

After patching:

  # echo sys_open > set_graph_function
  # echo sys_close >> set_graph_function
  # cat set_graph_function
  sys_open
  sys_close
  # echo '!sys_close' >> set_graph_function
  # cat set_graph_function
  sys_open
Signed-off-by: default avatarLi Zefan <lizf@cn.fujitsu.com>
LKML-Reference: <4B726388.2000408@cn.fujitsu.com>
Signed-off-by: default avatarSteven Rostedt <rostedt@goodmis.org>
parent ede55c9d
......@@ -2426,6 +2426,7 @@ static const struct file_operations ftrace_notrace_fops = {
static DEFINE_MUTEX(graph_lock);
int ftrace_graph_count;
int ftrace_graph_filter_enabled;
unsigned long ftrace_graph_funcs[FTRACE_GRAPH_MAX_FUNCS] __read_mostly;
static void *
......@@ -2448,7 +2449,7 @@ static void *g_start(struct seq_file *m, loff_t *pos)
mutex_lock(&graph_lock);
/* Nothing, tell g_show to print all functions are enabled */
if (!ftrace_graph_count && !*pos)
if (!ftrace_graph_filter_enabled && !*pos)
return (void *)1;
return __g_next(m, pos);
......@@ -2494,6 +2495,7 @@ ftrace_graph_open(struct inode *inode, struct file *file)
mutex_lock(&graph_lock);
if ((file->f_mode & FMODE_WRITE) &&
(file->f_flags & O_TRUNC)) {
ftrace_graph_filter_enabled = 0;
ftrace_graph_count = 0;
memset(ftrace_graph_funcs, 0, sizeof(ftrace_graph_funcs));
}
......@@ -2519,7 +2521,7 @@ ftrace_set_func(unsigned long *array, int *idx, char *buffer)
struct dyn_ftrace *rec;
struct ftrace_page *pg;
int search_len;
int found = 0;
int fail = 1;
int type, not;
char *search;
bool exists;
......@@ -2530,37 +2532,51 @@ ftrace_set_func(unsigned long *array, int *idx, char *buffer)
/* decode regex */
type = filter_parse_regex(buffer, strlen(buffer), &search, &not);
if (not)
return -EINVAL;
if (!not && *idx >= FTRACE_GRAPH_MAX_FUNCS)
return -EBUSY;
search_len = strlen(search);
mutex_lock(&ftrace_lock);
do_for_each_ftrace_rec(pg, rec) {
if (*idx >= FTRACE_GRAPH_MAX_FUNCS)
break;
if (rec->flags & (FTRACE_FL_FAILED | FTRACE_FL_FREE))
continue;
if (ftrace_match_record(rec, search, search_len, type)) {
/* ensure it is not already in the array */
/* if it is in the array */
exists = false;
for (i = 0; i < *idx; i++)
for (i = 0; i < *idx; i++) {
if (array[i] == rec->ip) {
exists = true;
break;
}
if (!exists)
array[(*idx)++] = rec->ip;
found = 1;
}
if (!not) {
fail = 0;
if (!exists) {
array[(*idx)++] = rec->ip;
if (*idx >= FTRACE_GRAPH_MAX_FUNCS)
goto out;
}
} else {
if (exists) {
array[i] = array[--(*idx)];
array[*idx] = 0;
fail = 0;
}
}
}
} while_for_each_ftrace_rec();
out:
mutex_unlock(&ftrace_lock);
return found ? 0 : -EINVAL;
if (fail)
return -EINVAL;
ftrace_graph_filter_enabled = 1;
return 0;
}
static ssize_t
......@@ -2570,16 +2586,11 @@ ftrace_graph_write(struct file *file, const char __user *ubuf,
struct trace_parser parser;
ssize_t read, ret;
if (!cnt || cnt < 0)
if (!cnt)
return 0;
mutex_lock(&graph_lock);
if (ftrace_graph_count >= FTRACE_GRAPH_MAX_FUNCS) {
ret = -EBUSY;
goto out_unlock;
}
if (trace_parser_get_init(&parser, FTRACE_BUFF_MAX)) {
ret = -ENOMEM;
goto out_unlock;
......
......@@ -497,6 +497,7 @@ trace_print_graph_duration(unsigned long long duration, struct trace_seq *s);
#ifdef CONFIG_DYNAMIC_FTRACE
/* TODO: make this variable */
#define FTRACE_GRAPH_MAX_FUNCS 32
extern int ftrace_graph_filter_enabled;
extern int ftrace_graph_count;
extern unsigned long ftrace_graph_funcs[FTRACE_GRAPH_MAX_FUNCS];
......@@ -504,7 +505,7 @@ static inline int ftrace_graph_addr(unsigned long addr)
{
int i;
if (!ftrace_graph_count)
if (!ftrace_graph_filter_enabled)
return 1;
for (i = 0; i < ftrace_graph_count; i++) {
......
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