Re: [PATCH v1] perf build: Add -funsigned-char to default CFLAGS

[Namhyung Kim]

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@xxxxxxxxxx> 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@xxxxxxxxxx>

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
> >