* [PATCH v3] tracing/eprobe: no need to check for negative ret value for snprintf
@ 2023-01-09 4:06 Quanfa Fu
2023-01-09 14:59 ` Masami Hiramatsu
0 siblings, 1 reply; 4+ messages in thread
From: Quanfa Fu @ 2023-01-09 4:06 UTC (permalink / raw)
To: rostedt, mhiramat; +Cc: linux-kernel, linux-trace-kernel, Quanfa Fu
No need to check for negative return value from snprintf() as the
code does not return negative values.
Signed-off-by: Quanfa Fu <quanfafu@gmail.com>
-----
V2 -> V3: continue to use snprintf
V1 -> V2: memory allc uses kzalloc and replace snprintf with memcpy
---
kernel/trace/trace_eprobe.c | 12 ++++--------
1 file changed, 4 insertions(+), 8 deletions(-)
diff --git a/kernel/trace/trace_eprobe.c b/kernel/trace/trace_eprobe.c
index 352b65e2b910..594ac1d086aa 100644
--- a/kernel/trace/trace_eprobe.c
+++ b/kernel/trace/trace_eprobe.c
@@ -923,17 +923,13 @@ static int trace_eprobe_parse_filter(struct trace_eprobe *ep, int argc, const ch
p = ep->filter_str;
for (i = 0; i < argc; i++) {
- ret = snprintf(p, len, "%s ", argv[i]);
- if (ret < 0)
- goto error;
- if (ret > len) {
- ret = -E2BIG;
- goto error;
- }
+ if (i)
+ ret = snprintf(p, len, " %s", argv[i]);
+ else
+ ret = snprintf(p, len, "%s", argv[i]);
p += ret;
len -= ret;
}
- p[-1] = '\0';
/*
* Ensure the filter string can be parsed correctly. Note, this
--
2.31.1
^ permalink raw reply related [flat|nested] 4+ messages in thread* Re: [PATCH v3] tracing/eprobe: no need to check for negative ret value for snprintf
2023-01-09 4:06 [PATCH v3] tracing/eprobe: no need to check for negative ret value for snprintf Quanfa Fu
@ 2023-01-09 14:59 ` Masami Hiramatsu
2023-01-09 15:12 ` Steven Rostedt
0 siblings, 1 reply; 4+ messages in thread
From: Masami Hiramatsu @ 2023-01-09 14:59 UTC (permalink / raw)
To: Quanfa Fu; +Cc: rostedt, linux-kernel, linux-trace-kernel
On Mon, 9 Jan 2023 12:06:25 +0800
Quanfa Fu <quanfafu@gmail.com> wrote:
> No need to check for negative return value from snprintf() as the
> code does not return negative values.
>
Thanks for simplifying, this looks good to me.
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
> Signed-off-by: Quanfa Fu <quanfafu@gmail.com>
>
> -----
> V2 -> V3: continue to use snprintf
> V1 -> V2: memory allc uses kzalloc and replace snprintf with memcpy
> ---
> kernel/trace/trace_eprobe.c | 12 ++++--------
> 1 file changed, 4 insertions(+), 8 deletions(-)
>
> diff --git a/kernel/trace/trace_eprobe.c b/kernel/trace/trace_eprobe.c
> index 352b65e2b910..594ac1d086aa 100644
> --- a/kernel/trace/trace_eprobe.c
> +++ b/kernel/trace/trace_eprobe.c
> @@ -923,17 +923,13 @@ static int trace_eprobe_parse_filter(struct trace_eprobe *ep, int argc, const ch
>
> p = ep->filter_str;
> for (i = 0; i < argc; i++) {
> - ret = snprintf(p, len, "%s ", argv[i]);
> - if (ret < 0)
> - goto error;
> - if (ret > len) {
> - ret = -E2BIG;
> - goto error;
> - }
> + if (i)
> + ret = snprintf(p, len, " %s", argv[i]);
> + else
> + ret = snprintf(p, len, "%s", argv[i]);
> p += ret;
> len -= ret;
> }
> - p[-1] = '\0';
>
> /*
> * Ensure the filter string can be parsed correctly. Note, this
> --
> 2.31.1
>
--
Masami Hiramatsu (Google) <mhiramat@kernel.org>
^ permalink raw reply [flat|nested] 4+ messages in thread* Re: [PATCH v3] tracing/eprobe: no need to check for negative ret value for snprintf
2023-01-09 14:59 ` Masami Hiramatsu
@ 2023-01-09 15:12 ` Steven Rostedt
2023-01-10 0:29 ` Masami Hiramatsu
0 siblings, 1 reply; 4+ messages in thread
From: Steven Rostedt @ 2023-01-09 15:12 UTC (permalink / raw)
To: Masami Hiramatsu (Google); +Cc: Quanfa Fu, linux-kernel, linux-trace-kernel
On Mon, 9 Jan 2023 23:59:13 +0900
Masami Hiramatsu (Google) <mhiramat@kernel.org> wrote:
> On Mon, 9 Jan 2023 12:06:25 +0800
> Quanfa Fu <quanfafu@gmail.com> wrote:
>
> > No need to check for negative return value from snprintf() as the
> > code does not return negative values.
> >
>
> Thanks for simplifying, this looks good to me.
>
> Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Masami, do you want to take it into the probes branch, or do you want me to
take it into the tracing branch?
-- Steve
>
> > Signed-off-by: Quanfa Fu <quanfafu@gmail.com>
> >
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH v3] tracing/eprobe: no need to check for negative ret value for snprintf
2023-01-09 15:12 ` Steven Rostedt
@ 2023-01-10 0:29 ` Masami Hiramatsu
0 siblings, 0 replies; 4+ messages in thread
From: Masami Hiramatsu @ 2023-01-10 0:29 UTC (permalink / raw)
To: Steven Rostedt; +Cc: Quanfa Fu, linux-kernel, linux-trace-kernel
On Mon, 9 Jan 2023 10:12:26 -0500
Steven Rostedt <rostedt@goodmis.org> wrote:
> On Mon, 9 Jan 2023 23:59:13 +0900
> Masami Hiramatsu (Google) <mhiramat@kernel.org> wrote:
>
> > On Mon, 9 Jan 2023 12:06:25 +0800
> > Quanfa Fu <quanfafu@gmail.com> wrote:
> >
> > > No need to check for negative return value from snprintf() as the
> > > code does not return negative values.
> > >
> >
> > Thanks for simplifying, this looks good to me.
> >
> > Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
>
> Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org>
>
> Masami, do you want to take it into the probes branch, or do you want me to
> take it into the tracing branch?
Yes, I'll take it to probe/for-next.
Thank you!
>
> -- Steve
>
>
> >
> > > Signed-off-by: Quanfa Fu <quanfafu@gmail.com>
> > >
--
Masami Hiramatsu (Google) <mhiramat@kernel.org>
^ permalink raw reply [flat|nested] 4+ messages in thread
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2023-01-09 4:06 [PATCH v3] tracing/eprobe: no need to check for negative ret value for snprintf Quanfa Fu
2023-01-09 14:59 ` Masami Hiramatsu
2023-01-09 15:12 ` Steven Rostedt
2023-01-10 0:29 ` Masami Hiramatsu
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