Re: [PATCH v7 13/14] perf callchain: Support x86 target platform

Jiri Olsa
2016-06-01T08:40:35Z

On Tue, May 31, 2016 at 11:19:11AM +0000, He Kuang wrote:

SNIP

> diff --git a/tools/perf/util/unwind-libunwind.c b/tools/perf/util/unwind-libunwind.c
> index e183390..5774317 100644
> --- a/tools/perf/util/unwind-libunwind.c
> +++ b/tools/perf/util/unwind-libunwind.c
> @@ -5,6 +5,7 @@
> #include "arch/common.h"
>
> struct unwind_libunwind_ops __weak *local_unwind_libunwind_ops;
> +struct unwind_libunwind_ops __weak *x86_32_unwind_libunwind_ops;
>
> void unwind__register_ops(struct thread *thread,
> struct unwind_libunwind_ops *ops)
> @@ -30,7 +31,13 @@ int unwind__prepare_access(struct thread *thread, struct map *map)
> dso_type == DSO__TYPE_64BIT, map->dso->name);
>
> arch = normalize_arch(thread->mg->machine->env->arch);
> - pr_debug("unwind: target platform=%s\n", arch);
> +
> + if (!strcmp(arch, "x86"))
> + if (dso_type != DSO__TYPE_64BIT)
> + ops = x86_32_unwind_libunwind_ops;
> +
> + if (!ops)
> + pr_err("unwind: target platform=%s is not supported\n", arch);

how could ops become NULL in here? it starts with local_unwind_libunwind_ops
I dont think this check is needed in here

jirka