[for-next][PATCH 4/9] ftrace: Clarify code for mod command

From: Steven Rostedt
Date: Wed Oct 21 2015 - 09:38:31 EST


From: Dmitry Safonov <0x7f454c46@xxxxxxxxx>

"Not" is too abstract variable name - changed to clear_filter.
Removed ftrace_match_module_records function: comparison with !* or *
not does the general code in filter_parse_regex() as it works without
mod command for
sh# echo '!*' > /sys/kernel/debug/tracing/set_ftrace_filter

Link: http://lkml.kernel.org/r/1443545176-3215-2-git-send-email-0x7f454c46@xxxxxxxxx

Signed-off-by: Dmitry Safonov <0x7f454c46@xxxxxxxxx>
Signed-off-by: Steven Rostedt <rostedt@xxxxxxxxxxx>
---
kernel/trace/ftrace.c | 37 ++++++++++---------------------------
1 file changed, 10 insertions(+), 27 deletions(-)

diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index 8892b45b4368..fc755a49704f 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -3454,13 +3454,13 @@ static int ftrace_match(char *str, char *regex, int len, int type)
}

static int
-enter_record(struct ftrace_hash *hash, struct dyn_ftrace *rec, int not)
+enter_record(struct ftrace_hash *hash, struct dyn_ftrace *rec, int clear_filter)
{
struct ftrace_func_entry *entry;
int ret = 0;

entry = ftrace_lookup_ip(hash, rec->ip);
- if (not) {
+ if (clear_filter) {
/* Do nothing if it doesn't exist */
if (!entry)
return 0;
@@ -3499,8 +3499,7 @@ ftrace_match_record(struct dyn_ftrace *rec, char *mod,
}

static int
-match_records(struct ftrace_hash *hash, char *buff,
- int len, char *mod, int not)
+match_records(struct ftrace_hash *hash, char *buff, int len, char *mod)
{
unsigned search_len = 0;
struct ftrace_page *pg;
@@ -3509,9 +3508,10 @@ match_records(struct ftrace_hash *hash, char *buff,
char *search = buff;
int found = 0;
int ret;
+ int clear_filter;

if (len) {
- type = filter_parse_regex(buff, len, &search, &not);
+ type = filter_parse_regex(buff, len, &search, &clear_filter);
search_len = strlen(search);
}

@@ -3522,7 +3522,7 @@ match_records(struct ftrace_hash *hash, char *buff,

do_for_each_ftrace_rec(pg, rec) {
if (ftrace_match_record(rec, mod, search, search_len, type)) {
- ret = enter_record(hash, rec, not);
+ ret = enter_record(hash, rec, clear_filter);
if (ret < 0) {
found = ret;
goto out_unlock;
@@ -3539,26 +3539,9 @@ match_records(struct ftrace_hash *hash, char *buff,
static int
ftrace_match_records(struct ftrace_hash *hash, char *buff, int len)
{
- return match_records(hash, buff, len, NULL, 0);
+ return match_records(hash, buff, len, NULL);
}

-static int
-ftrace_match_module_records(struct ftrace_hash *hash, char *buff, char *mod)
-{
- int not = 0;
-
- /* blank or '*' mean the same */
- if (strcmp(buff, "*") == 0)
- buff[0] = 0;
-
- /* handle the case of 'dont filter this module' */
- if (strcmp(buff, "!") == 0 || strcmp(buff, "!*") == 0) {
- buff[0] = 0;
- not = 1;
- }
-
- return match_records(hash, buff, strlen(buff), mod, not);
-}

/*
* We register the module command as a template to show others how
@@ -3567,7 +3550,7 @@ ftrace_match_module_records(struct ftrace_hash *hash, char *buff, char *mod)

static int
ftrace_mod_callback(struct ftrace_hash *hash,
- char *func, char *cmd, char *param, int enable)
+ char *func, char *cmd, char *module, int enable)
{
int ret;

@@ -3580,10 +3563,10 @@ ftrace_mod_callback(struct ftrace_hash *hash,
*/

/* we must have a module name */
- if (!param || !strlen(param))
+ if (!module || !strlen(module))
return -EINVAL;

- ret = ftrace_match_module_records(hash, func, param);
+ ret = match_records(hash, func, strlen(func), module);
if (!ret)
return -EINVAL;
if (ret < 0)
--
2.6.1


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