Re: [PATCH v2] perf symbols: Fix annotation of objects with debuginfo files

From: Naveen N. Rao
Date: Sun Aug 14 2016 - 12:57:27 EST


On 2016/08/13 11:55AM, Anton Blanchard wrote:
> From: Anton Blanchard <anton@xxxxxxxxx>
>
> Commit 73cdf0c6ea9c ("perf symbols: Record text offset in dso
> to calculate objdump address") started storing the offset of
> the text section for all DSOs:
>
> if (elf_section_by_name(elf, &ehdr, &tshdr, ".text", NULL))
> dso->text_offset = tshdr.sh_addr - tshdr.sh_offset;
>
> Unfortunately this breaks debuginfo files, because we need to calculate
> the offset of the text section in the associated executable file. As a
> result perf annotate returns junk for all debuginfo files.
>
> Fix this by using runtime_ss->elf which should point at the executable
> when parsing a debuginfo file.
>
> Cc: stable@xxxxxxxxxxxxxxx # v4.6+
> Fixes: 73cdf0c6ea9c ("perf symbols: Record text offset in dso to calculate objdump address")
> Signed-off-by: Anton Blanchard <anton@xxxxxxxxx>
> ---
>
> v2: Fix from Naveen
>
> diff --git a/tools/perf/util/symbol-elf.c b/tools/perf/util/symbol-elf.c
> index a34321e..a811c13 100644
> --- a/tools/perf/util/symbol-elf.c
> +++ b/tools/perf/util/symbol-elf.c
> @@ -837,7 +837,8 @@ int dso__load_sym(struct dso *dso, struct map *map,
> sec = syms_ss->symtab;
> shdr = syms_ss->symshdr;
>
> - if (elf_section_by_name(elf, &ehdr, &tshdr, ".text", NULL))
> + if (elf_section_by_name(runtime_ss->elf, &runtime_ss->ehdr, &tshdr,
> + ".text", NULL))
> dso->text_offset = tshdr.sh_addr - tshdr.sh_offset;
>
> if (runtime_ss->opdsec)

Reviewed-by: Naveen N. Rao <naveen.n.rao@xxxxxxxxxxxxxxxxxx>

Thanks Anton!
- Naveen