[PATCH] perf: arm64: Fix compilation error

[James Clark]

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 at arm.com>
> ---
>   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 at linaro.org>