* [PATCH 1/2] ftrace: remove an unneeded NULL check
@ 2017-07-12 7:33 ` Dan Carpenter
0 siblings, 0 replies; 6+ messages in thread
From: Dan Carpenter @ 2017-07-12 7:33 UTC (permalink / raw)
To: Steven Rostedt; +Cc: Ingo Molnar, linux-kernel, kernel-janitors
"func" can't be NULL and it doesn't make sense to check because we've
already derefenced it.
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index 2953d558bbee..2a3c45743f54 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -3950,7 +3950,7 @@ static int cache_mod(struct trace_array *tr,
continue;
/* no func matches all */
- if (!func || strcmp(func, "*") == 0 ||
+ if (strcmp(func, "*") == 0 ||
(ftrace_mod->func &&
strcmp(ftrace_mod->func, func) == 0)) {
ret = 0;
^ permalink raw reply related [flat|nested] 6+ messages in thread* [PATCH 1/2] ftrace: remove an unneeded NULL check
@ 2017-07-12 7:33 ` Dan Carpenter
0 siblings, 0 replies; 6+ messages in thread
From: Dan Carpenter @ 2017-07-12 7:33 UTC (permalink / raw)
To: Steven Rostedt; +Cc: Ingo Molnar, linux-kernel, kernel-janitors
"func" can't be NULL and it doesn't make sense to check because we've
already derefenced it.
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index 2953d558bbee..2a3c45743f54 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -3950,7 +3950,7 @@ static int cache_mod(struct trace_array *tr,
continue;
/* no func matches all */
- if (!func || strcmp(func, "*") = 0 ||
+ if (strcmp(func, "*") = 0 ||
(ftrace_mod->func &&
strcmp(ftrace_mod->func, func) = 0)) {
ret = 0;
^ permalink raw reply related [flat|nested] 6+ messages in thread* [PATCH 2/2] ftrace: silence uninitialized variable warning
2017-07-12 7:33 ` Dan Carpenter
@ 2017-07-12 7:35 ` Dan Carpenter
-1 siblings, 0 replies; 6+ messages in thread
From: Dan Carpenter @ 2017-07-12 7:35 UTC (permalink / raw)
To: Steven Rostedt; +Cc: Ingo Molnar, linux-kernel, kernel-janitors
My static checker complains that if "func" is NULL then "clear_filter"
is uninitialized. This seems like it could be true, although it's
possible something subtle is happening that I haven't seen.
kernel/trace/ftrace.c:3844 match_records()
error: uninitialized symbol 'clear_filter'.
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
---
It does occur to me that I could initialize it to 1 instead of 0 but my
guess is that zero is intended. Please review this one carefully.
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index 2a3c45743f54..5e658da91912 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -3816,7 +3816,7 @@ match_records(struct ftrace_hash *hash, char *func, int len, char *mod)
int exclude_mod = 0;
int found = 0;
int ret;
- int clear_filter;
+ int clear_filter = 0;
if (func) {
func_g.type = filter_parse_regex(func, len, &func_g.search,
^ permalink raw reply related [flat|nested] 6+ messages in thread* [PATCH 2/2] ftrace: silence uninitialized variable warning
@ 2017-07-12 7:35 ` Dan Carpenter
0 siblings, 0 replies; 6+ messages in thread
From: Dan Carpenter @ 2017-07-12 7:35 UTC (permalink / raw)
To: Steven Rostedt; +Cc: Ingo Molnar, linux-kernel, kernel-janitors
My static checker complains that if "func" is NULL then "clear_filter"
is uninitialized. This seems like it could be true, although it's
possible something subtle is happening that I haven't seen.
kernel/trace/ftrace.c:3844 match_records()
error: uninitialized symbol 'clear_filter'.
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
---
It does occur to me that I could initialize it to 1 instead of 0 but my
guess is that zero is intended. Please review this one carefully.
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index 2a3c45743f54..5e658da91912 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -3816,7 +3816,7 @@ match_records(struct ftrace_hash *hash, char *func, int len, char *mod)
int exclude_mod = 0;
int found = 0;
int ret;
- int clear_filter;
+ int clear_filter = 0;
if (func) {
func_g.type = filter_parse_regex(func, len, &func_g.search,
^ permalink raw reply related [flat|nested] 6+ messages in thread* Re: [PATCH 2/2] ftrace: silence uninitialized variable warning
2017-07-12 7:35 ` Dan Carpenter
@ 2017-07-12 13:45 ` Steven Rostedt
-1 siblings, 0 replies; 6+ messages in thread
From: Steven Rostedt @ 2017-07-12 13:45 UTC (permalink / raw)
To: Dan Carpenter; +Cc: Ingo Molnar, linux-kernel, kernel-janitors
On Wed, 12 Jul 2017 10:35:57 +0300
Dan Carpenter <dan.carpenter@oracle.com> wrote:
> My static checker complains that if "func" is NULL then "clear_filter"
> is uninitialized. This seems like it could be true, although it's
> possible something subtle is happening that I haven't seen.
>
> kernel/trace/ftrace.c:3844 match_records()
> error: uninitialized symbol 'clear_filter'.
>
> Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
> ---
> It does occur to me that I could initialize it to 1 instead of 0 but my
> guess is that zero is intended. Please review this one carefully.
Looks like it broke with f0a3b154bd7 ("ftrace: Clarify code for mod
command"). Yeah, clear_filter = 0 is the correct default.
Thanks!
-- Steve
>
> diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
> index 2a3c45743f54..5e658da91912 100644
> --- a/kernel/trace/ftrace.c
> +++ b/kernel/trace/ftrace.c
> @@ -3816,7 +3816,7 @@ match_records(struct ftrace_hash *hash, char *func, int len, char *mod)
> int exclude_mod = 0;
> int found = 0;
> int ret;
> - int clear_filter;
> + int clear_filter = 0;
>
> if (func) {
> func_g.type = filter_parse_regex(func, len, &func_g.search,
^ permalink raw reply [flat|nested] 6+ messages in thread* Re: [PATCH 2/2] ftrace: silence uninitialized variable warning
@ 2017-07-12 13:45 ` Steven Rostedt
0 siblings, 0 replies; 6+ messages in thread
From: Steven Rostedt @ 2017-07-12 13:45 UTC (permalink / raw)
To: Dan Carpenter; +Cc: Ingo Molnar, linux-kernel, kernel-janitors
On Wed, 12 Jul 2017 10:35:57 +0300
Dan Carpenter <dan.carpenter@oracle.com> wrote:
> My static checker complains that if "func" is NULL then "clear_filter"
> is uninitialized. This seems like it could be true, although it's
> possible something subtle is happening that I haven't seen.
>
> kernel/trace/ftrace.c:3844 match_records()
> error: uninitialized symbol 'clear_filter'.
>
> Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
> ---
> It does occur to me that I could initialize it to 1 instead of 0 but my
> guess is that zero is intended. Please review this one carefully.
Looks like it broke with f0a3b154bd7 ("ftrace: Clarify code for mod
command"). Yeah, clear_filter = 0 is the correct default.
Thanks!
-- Steve
>
> diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
> index 2a3c45743f54..5e658da91912 100644
> --- a/kernel/trace/ftrace.c
> +++ b/kernel/trace/ftrace.c
> @@ -3816,7 +3816,7 @@ match_records(struct ftrace_hash *hash, char *func, int len, char *mod)
> int exclude_mod = 0;
> int found = 0;
> int ret;
> - int clear_filter;
> + int clear_filter = 0;
>
> if (func) {
> func_g.type = filter_parse_regex(func, len, &func_g.search,
^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2017-07-12 13:45 UTC | newest]
Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed)
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2017-07-12 7:33 [PATCH 1/2] ftrace: remove an unneeded NULL check Dan Carpenter
2017-07-12 7:33 ` Dan Carpenter
2017-07-12 7:35 ` [PATCH 2/2] ftrace: silence uninitialized variable warning Dan Carpenter
2017-07-12 7:35 ` Dan Carpenter
2017-07-12 13:45 ` Steven Rostedt
2017-07-12 13:45 ` Steven Rostedt
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