Re: [PATCH] perf: arm64: Fix compilation error

[Namhyung Kim]

On Fri, Feb 14, 2025 at 11:21:52AM +0000, James Clark wrote:
> 
> 
> On 14/02/2025 11:10 am, Leo Yan wrote:
> > Since the commit dc6d2bc2d893 ("perf sample: Make user_regs and
> > intr_regs optional"), the building for Arm64 reports error:
> > 
> > arch/arm64/util/unwind-libdw.c: In function ‘libdw__arch_set_initial_registers’:
> > arch/arm64/util/unwind-libdw.c:11:32: error: initialization of ‘struct regs_dump *’ from incompatible pointer type ‘struct regs_dump **’ [-Werror=incompatible-pointer-types]
> >     11 |  struct regs_dump *user_regs = &ui->sample->user_regs;
> >        |                                ^
> > cc1: all warnings being treated as errors
> > make[6]: *** [/home/niayan01/linux/tools/build/Makefile.build:85: arch/arm64/util/unwind-libdw.o] Error 1
> > make[5]: *** [/home/niayan01/linux/tools/build/Makefile.build:138: util] Error 2
> > arch/arm64/tests/dwarf-unwind.c: In function ‘test__arch_unwind_sample’:
> > arch/arm64/tests/dwarf-unwind.c:48:27: error: initialization of ‘struct regs_dump *’ from incompatible pointer type ‘struct regs_dump **’ [-Werror=incompatible-pointer-types]
> >     48 |  struct regs_dump *regs = &sample->user_regs;
> >        |                           ^
> > 
> > To fix the issue, use the helper perf_sample__user_regs() to retrieve
> > the user_regs.
> > 
> > Fixes: dc6d2bc2d893 ("perf sample: Make user_regs and intr_regs optional")
> > Signed-off-by: Leo Yan <leo.yan@xxxxxxx>

Thanks for the fix, I'll handle other archs too
Namhyung


> > ---
> >   tools/perf/arch/arm64/tests/dwarf-unwind.c | 2 +-
> >   tools/perf/arch/arm64/util/unwind-libdw.c  | 2 +-
> >   2 files changed, 2 insertions(+), 2 deletions(-)
> > 
> > diff --git a/tools/perf/arch/arm64/tests/dwarf-unwind.c b/tools/perf/arch/arm64/tests/dwarf-unwind.c
> > index b2603d0d3737..440d00f0de14 100644
> > --- a/tools/perf/arch/arm64/tests/dwarf-unwind.c
> > +++ b/tools/perf/arch/arm64/tests/dwarf-unwind.c
> > @@ -45,7 +45,7 @@ static int sample_ustack(struct perf_sample *sample,
> >   int test__arch_unwind_sample(struct perf_sample *sample,
> >   		struct thread *thread)
> >   {
> > -	struct regs_dump *regs = &sample->user_regs;
> > +	struct regs_dump *regs = perf_sample__user_regs(sample);
> >   	u64 *buf;
> >   	buf = calloc(1, sizeof(u64) * PERF_REGS_MAX);
> > diff --git a/tools/perf/arch/arm64/util/unwind-libdw.c b/tools/perf/arch/arm64/util/unwind-libdw.c
> > index e056d50ab42e..b89b0a7e5ad9 100644
> > --- a/tools/perf/arch/arm64/util/unwind-libdw.c
> > +++ b/tools/perf/arch/arm64/util/unwind-libdw.c
> > @@ -8,7 +8,7 @@
> >   bool libdw__arch_set_initial_registers(Dwfl_Thread *thread, void *arg)
> >   {
> >   	struct unwind_info *ui = arg;
> > -	struct regs_dump *user_regs = &ui->sample->user_regs;
> > +	struct regs_dump *user_regs = perf_sample__user_regs(ui->sample);
> >   	Dwarf_Word dwarf_regs[PERF_REG_ARM64_MAX], dwarf_pc;
> >   #define REG(r) ({						\
> 
> Reviewed-by: James Clark <james.clark@xxxxxxxxxx>
>