* [PATCH v1] perf build: Add -funsigned-char to default CFLAGS
@ 2026-03-06 19:19 Ian Rogers
2026-03-20 23:00 ` Ian Rogers
0 siblings, 1 reply; 4+ messages in thread
From: Ian Rogers @ 2026-03-06 19:19 UTC (permalink / raw)
To: Peter Zijlstra, Ingo Molnar, Arnaldo Carvalho de Melo,
Namhyung Kim, Jiri Olsa, Ian Rogers, Adrian Hunter, James Clark,
linux-perf-users, linux-kernel
Commit 3bc753c06dd0 ("kbuild: treat char as always unsigned") made
chars unsigned by default in the Linux kernel. To avoid similar kinds
of bugs and warnings, make unsigned chars the default for the perf tool.
Signed-off-by: Ian Rogers <irogers@google.com>
---
tools/perf/Makefile.config | 1 +
1 file changed, 1 insertion(+)
diff --git a/tools/perf/Makefile.config b/tools/perf/Makefile.config
index a8dc72cfe48e..3820bdf73f43 100644
--- a/tools/perf/Makefile.config
+++ b/tools/perf/Makefile.config
@@ -349,6 +349,7 @@ CORE_CFLAGS += -fno-omit-frame-pointer
CORE_CFLAGS += -Wall
CORE_CFLAGS += -Wextra
CORE_CFLAGS += -std=gnu11
+CORE_CFLAGS += -funsigned-char
CXXFLAGS += -std=gnu++17 -fno-exceptions -fno-rtti
CXXFLAGS += -Wall
--
2.53.0.473.g4a7958ca14-goog
^ permalink raw reply related [flat|nested] 4+ messages in thread* Re: [PATCH v1] perf build: Add -funsigned-char to default CFLAGS
2026-03-06 19:19 [PATCH v1] perf build: Add -funsigned-char to default CFLAGS Ian Rogers
@ 2026-03-20 23:00 ` Ian Rogers
2026-03-26 22:17 ` Namhyung Kim
0 siblings, 1 reply; 4+ messages in thread
From: Ian Rogers @ 2026-03-20 23:00 UTC (permalink / raw)
To: Peter Zijlstra, Ingo Molnar, Arnaldo Carvalho de Melo,
Namhyung Kim, Jiri Olsa, Ian Rogers, Adrian Hunter, James Clark,
linux-perf-users, linux-kernel
On Fri, Mar 6, 2026 at 11:19 AM Ian Rogers <irogers@google.com> wrote:
>
> Commit 3bc753c06dd0 ("kbuild: treat char as always unsigned") made
> chars unsigned by default in the Linux kernel. To avoid similar kinds
> of bugs and warnings, make unsigned chars the default for the perf tool.
>
> Signed-off-by: Ian Rogers <irogers@google.com>
Ping.
Thanks,
Ian
> ---
> tools/perf/Makefile.config | 1 +
> 1 file changed, 1 insertion(+)
>
> diff --git a/tools/perf/Makefile.config b/tools/perf/Makefile.config
> index a8dc72cfe48e..3820bdf73f43 100644
> --- a/tools/perf/Makefile.config
> +++ b/tools/perf/Makefile.config
> @@ -349,6 +349,7 @@ CORE_CFLAGS += -fno-omit-frame-pointer
> CORE_CFLAGS += -Wall
> CORE_CFLAGS += -Wextra
> CORE_CFLAGS += -std=gnu11
> +CORE_CFLAGS += -funsigned-char
>
> CXXFLAGS += -std=gnu++17 -fno-exceptions -fno-rtti
> CXXFLAGS += -Wall
> --
> 2.53.0.473.g4a7958ca14-goog
>
^ permalink raw reply [flat|nested] 4+ messages in thread* Re: [PATCH v1] perf build: Add -funsigned-char to default CFLAGS
2026-03-20 23:00 ` Ian Rogers
@ 2026-03-26 22:17 ` Namhyung Kim
2026-03-26 23:18 ` Ian Rogers
0 siblings, 1 reply; 4+ messages in thread
From: Namhyung Kim @ 2026-03-26 22:17 UTC (permalink / raw)
To: Ian Rogers
Cc: Peter Zijlstra, Ingo Molnar, Arnaldo Carvalho de Melo, Jiri Olsa,
Adrian Hunter, James Clark, linux-perf-users, linux-kernel
On Fri, Mar 20, 2026 at 04:00:56PM -0700, Ian Rogers wrote:
> On Fri, Mar 6, 2026 at 11:19 AM Ian Rogers <irogers@google.com> wrote:
> >
> > Commit 3bc753c06dd0 ("kbuild: treat char as always unsigned") made
> > chars unsigned by default in the Linux kernel. To avoid similar kinds
> > of bugs and warnings, make unsigned chars the default for the perf tool.
> >
> > Signed-off-by: Ian Rogers <irogers@google.com>
Do you know what the actual bug was?
Thanks,
Namhyung
>
> > ---
> > tools/perf/Makefile.config | 1 +
> > 1 file changed, 1 insertion(+)
> >
> > diff --git a/tools/perf/Makefile.config b/tools/perf/Makefile.config
> > index a8dc72cfe48e..3820bdf73f43 100644
> > --- a/tools/perf/Makefile.config
> > +++ b/tools/perf/Makefile.config
> > @@ -349,6 +349,7 @@ CORE_CFLAGS += -fno-omit-frame-pointer
> > CORE_CFLAGS += -Wall
> > CORE_CFLAGS += -Wextra
> > CORE_CFLAGS += -std=gnu11
> > +CORE_CFLAGS += -funsigned-char
> >
> > CXXFLAGS += -std=gnu++17 -fno-exceptions -fno-rtti
> > CXXFLAGS += -Wall
> > --
> > 2.53.0.473.g4a7958ca14-goog
> >
^ permalink raw reply [flat|nested] 4+ messages in thread* Re: [PATCH v1] perf build: Add -funsigned-char to default CFLAGS
2026-03-26 22:17 ` Namhyung Kim
@ 2026-03-26 23:18 ` Ian Rogers
0 siblings, 0 replies; 4+ messages in thread
From: Ian Rogers @ 2026-03-26 23:18 UTC (permalink / raw)
To: Namhyung Kim
Cc: Peter Zijlstra, Ingo Molnar, Arnaldo Carvalho de Melo, Jiri Olsa,
Adrian Hunter, James Clark, linux-perf-users, linux-kernel
On Thu, Mar 26, 2026 at 3:17 PM Namhyung Kim <namhyung@kernel.org> wrote:
>
> On Fri, Mar 20, 2026 at 04:00:56PM -0700, Ian Rogers wrote:
> > On Fri, Mar 6, 2026 at 11:19 AM Ian Rogers <irogers@google.com> wrote:
> > >
> > > Commit 3bc753c06dd0 ("kbuild: treat char as always unsigned") made
> > > chars unsigned by default in the Linux kernel. To avoid similar kinds
> > > of bugs and warnings, make unsigned chars the default for the perf tool.
> > >
> > > Signed-off-by: Ian Rogers <irogers@google.com>
>
> Do you know what the actual bug was?
I don't, my motivation was to try to avoid sashiko warnings about
issues that occur with signed chars.
Thanks,
Ian
> Thanks,
> Namhyung
>
> >
> > > ---
> > > tools/perf/Makefile.config | 1 +
> > > 1 file changed, 1 insertion(+)
> > >
> > > diff --git a/tools/perf/Makefile.config b/tools/perf/Makefile.config
> > > index a8dc72cfe48e..3820bdf73f43 100644
> > > --- a/tools/perf/Makefile.config
> > > +++ b/tools/perf/Makefile.config
> > > @@ -349,6 +349,7 @@ CORE_CFLAGS += -fno-omit-frame-pointer
> > > CORE_CFLAGS += -Wall
> > > CORE_CFLAGS += -Wextra
> > > CORE_CFLAGS += -std=gnu11
> > > +CORE_CFLAGS += -funsigned-char
> > >
> > > CXXFLAGS += -std=gnu++17 -fno-exceptions -fno-rtti
> > > CXXFLAGS += -Wall
> > > --
> > > 2.53.0.473.g4a7958ca14-goog
> > >
^ permalink raw reply [flat|nested] 4+ messages in thread
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2026-03-06 19:19 [PATCH v1] perf build: Add -funsigned-char to default CFLAGS Ian Rogers
2026-03-20 23:00 ` Ian Rogers
2026-03-26 22:17 ` Namhyung Kim
2026-03-26 23:18 ` Ian Rogers
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