* [PATCH v1] perf string: Avoid undefined NULL+1
@ 2024-11-20 6:52 Ian Rogers
2024-12-09 11:49 ` James Clark
0 siblings, 1 reply; 3+ messages in thread
From: Ian Rogers @ 2024-11-20 6:52 UTC (permalink / raw)
To: Peter Zijlstra, Ingo Molnar, Arnaldo Carvalho de Melo,
Namhyung Kim, Mark Rutland, Alexander Shishkin, Jiri Olsa,
Ian Rogers, Adrian Hunter, Kan Liang, Masami Hiramatsu (Google),
linux-perf-users, linux-kernel
While the value NULL+1 is never used it triggers a ubsan
warning. Restructure and comment the loop to avoid this.
Signed-off-by: Ian Rogers <irogers@google.com>
---
tools/perf/util/string.c | 15 ++++++++++++---
1 file changed, 12 insertions(+), 3 deletions(-)
diff --git a/tools/perf/util/string.c b/tools/perf/util/string.c
index 308fc7ec88cc..c0e927bbadf6 100644
--- a/tools/perf/util/string.c
+++ b/tools/perf/util/string.c
@@ -254,11 +254,20 @@ char *strpbrk_esc(char *str, const char *stopset)
do {
ptr = strpbrk(str, stopset);
- if (ptr == str ||
- (ptr == str + 1 && *(ptr - 1) != '\\'))
+ if (!ptr) {
+ /* stopset not in str. */
break;
+ }
+ if (ptr == str) {
+ /* stopset character is first in str. */
+ break;
+ }
+ if (ptr == str + 1 && str[0] != '\\') {
+ /* stopset chacter is second and wasn't preceded by a '\'. */
+ break;
+ }
str = ptr + 1;
- } while (ptr && *(ptr - 1) == '\\' && *(ptr - 2) != '\\');
+ } while (ptr[-1] == '\\' && ptr[-2] != '\\');
return ptr;
}
--
2.47.0.371.ga323438b13-goog
^ permalink raw reply related [flat|nested] 3+ messages in thread* Re: [PATCH v1] perf string: Avoid undefined NULL+1
2024-11-20 6:52 [PATCH v1] perf string: Avoid undefined NULL+1 Ian Rogers
@ 2024-12-09 11:49 ` James Clark
2024-12-12 18:54 ` Arnaldo Carvalho de Melo
0 siblings, 1 reply; 3+ messages in thread
From: James Clark @ 2024-12-09 11:49 UTC (permalink / raw)
To: Ian Rogers, Arnaldo Carvalho de Melo, Namhyung Kim,
Masami Hiramatsu (Google)
Cc: linux-perf-users, linux-kernel, Mark Rutland, Alexander Shishkin,
Jiri Olsa, Adrian Hunter, Kan Liang, Peter Zijlstra, Ingo Molnar
On 20/11/2024 6:52 am, Ian Rogers wrote:
> While the value NULL+1 is never used it triggers a ubsan
> warning. Restructure and comment the loop to avoid this.
>
> Signed-off-by: Ian Rogers <irogers@google.com>
> ---
> tools/perf/util/string.c | 15 ++++++++++++---
> 1 file changed, 12 insertions(+), 3 deletions(-)
>
> diff --git a/tools/perf/util/string.c b/tools/perf/util/string.c
> index 308fc7ec88cc..c0e927bbadf6 100644
> --- a/tools/perf/util/string.c
> +++ b/tools/perf/util/string.c
> @@ -254,11 +254,20 @@ char *strpbrk_esc(char *str, const char *stopset)
>
> do {
> ptr = strpbrk(str, stopset);
> - if (ptr == str ||
> - (ptr == str + 1 && *(ptr - 1) != '\\'))
> + if (!ptr) {
> + /* stopset not in str. */
> break;
> + }
> + if (ptr == str) {
> + /* stopset character is first in str. */
> + break;
> + }
> + if (ptr == str + 1 && str[0] != '\\') {
> + /* stopset chacter is second and wasn't preceded by a '\'. */
> + break;
> + }
> str = ptr + 1;
> - } while (ptr && *(ptr - 1) == '\\' && *(ptr - 2) != '\\');
> + } while (ptr[-1] == '\\' && ptr[-2] != '\\');
>
> return ptr;
> }
Reviewed-by: James Clark <james.clark@linaro.org>
^ permalink raw reply [flat|nested] 3+ messages in thread* Re: [PATCH v1] perf string: Avoid undefined NULL+1
2024-12-09 11:49 ` James Clark
@ 2024-12-12 18:54 ` Arnaldo Carvalho de Melo
0 siblings, 0 replies; 3+ messages in thread
From: Arnaldo Carvalho de Melo @ 2024-12-12 18:54 UTC (permalink / raw)
To: James Clark
Cc: Ian Rogers, Namhyung Kim, Masami Hiramatsu (Google),
linux-perf-users, linux-kernel, Mark Rutland, Alexander Shishkin,
Jiri Olsa, Adrian Hunter, Kan Liang, Peter Zijlstra, Ingo Molnar
On Mon, Dec 09, 2024 at 11:49:15AM +0000, James Clark wrote:
> On 20/11/2024 6:52 am, Ian Rogers wrote:
> > While the value NULL+1 is never used it triggers a ubsan
> > warning. Restructure and comment the loop to avoid this.
> > Signed-off-by: Ian Rogers <irogers@google.com>
> > +++ b/tools/perf/util/string.c
> > @@ -254,11 +254,20 @@ char *strpbrk_esc(char *str, const char *stopset)
> > do {
> > ptr = strpbrk(str, stopset);
> > - if (ptr == str ||
> > - (ptr == str + 1 && *(ptr - 1) != '\\'))
> > + if (!ptr) {
> > + /* stopset not in str. */
> > break;
> > + }
> > + if (ptr == str) {
> > + /* stopset character is first in str. */
> > + break;
> > + }
> > + if (ptr == str + 1 && str[0] != '\\') {
> > + /* stopset chacter is second and wasn't preceded by a '\'. */
> > + break;
> > + }
> > str = ptr + 1;
> > - } while (ptr && *(ptr - 1) == '\\' && *(ptr - 2) != '\\');
> > + } while (ptr[-1] == '\\' && ptr[-2] != '\\');
> > return ptr;
> > }
> Reviewed-by: James Clark <james.clark@linaro.org>
Thanks, applied to perf-tools-next,
- Arnaldo
^ permalink raw reply [flat|nested] 3+ messages in thread
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2024-11-20 6:52 [PATCH v1] perf string: Avoid undefined NULL+1 Ian Rogers
2024-12-09 11:49 ` James Clark
2024-12-12 18:54 ` Arnaldo Carvalho de Melo
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