Re: [PATCH V2 1/9] perf tools: Fix symbol annotation for relocatedkernel

From: Adrian Hunter
Date: Thu Jan 30 2014 - 02:19:07 EST


On 29/01/14 20:57, Arnaldo Carvalho de Melo wrote:
> Em Wed, Jan 29, 2014 at 04:14:36PM +0200, Adrian Hunter escreveu:
>> Kernel maps map memory addresses to file offsets.
>> For symbol annotation, objdump needs the object VMA
>> addresses. For an unrelocated kernel, that is the
>> same as the memory address.
>>
>> The addresses passed to objdump for symbol annotation
>> did not take into account kernel relocation. This
>> patch fixes that.
>
> Question: To fix the problem reported by Linus, i.e. the very minimal
> fix, we only need this patch, right?

Yes but the other fixes are needed too.

>
> Reading the other patches now.
>
> - Arnaldo
>
>> Signed-off-by: Adrian Hunter <adrian.hunter@xxxxxxxxx>
>> ---
>> tools/perf/util/map.c | 5 +++--
>> tools/perf/util/map.h | 1 +
>> tools/perf/util/symbol-elf.c | 2 ++
>> 3 files changed, 6 insertions(+), 2 deletions(-)
>>
>> diff --git a/tools/perf/util/map.c b/tools/perf/util/map.c
>> index ee1dd68..b46f527 100644
>> --- a/tools/perf/util/map.c
>> +++ b/tools/perf/util/map.c
>> @@ -39,6 +39,7 @@ void map__init(struct map *map, enum map_type type,
>> map->start = start;
>> map->end = end;
>> map->pgoff = pgoff;
>> + map->reloc = 0;
>> map->dso = dso;
>> map->map_ip = map__map_ip;
>> map->unmap_ip = map__unmap_ip;
>> @@ -288,7 +289,7 @@ u64 map__rip_2objdump(struct map *map, u64 rip)
>> if (map->dso->rel)
>> return rip - map->pgoff;
>>
>> - return map->unmap_ip(map, rip);
>> + return map->unmap_ip(map, rip) - map->reloc;
>> }
>>
>> /**
>> @@ -311,7 +312,7 @@ u64 map__objdump_2mem(struct map *map, u64 ip)
>> if (map->dso->rel)
>> return map->unmap_ip(map, ip + map->pgoff);
>>
>> - return ip;
>> + return ip + map->reloc;
>> }
>>
>> void map_groups__init(struct map_groups *mg)
>> diff --git a/tools/perf/util/map.h b/tools/perf/util/map.h
>> index 18068c6..257e513 100644
>> --- a/tools/perf/util/map.h
>> +++ b/tools/perf/util/map.h
>> @@ -36,6 +36,7 @@ struct map {
>> bool erange_warned;
>> u32 priv;
>> u64 pgoff;
>> + u64 reloc;
>> u32 maj, min; /* only valid for MMAP2 record */
>> u64 ino; /* only valid for MMAP2 record */
>> u64 ino_generation;/* only valid for MMAP2 record */
>> diff --git a/tools/perf/util/symbol-elf.c b/tools/perf/util/symbol-elf.c
>> index 7594567..8ce52da 100644
>> --- a/tools/perf/util/symbol-elf.c
>> +++ b/tools/perf/util/symbol-elf.c
>> @@ -751,6 +751,8 @@ int dso__load_sym(struct dso *dso, struct map *map,
>> if (strcmp(elf_name, kmap->ref_reloc_sym->name))
>> continue;
>> kmap->ref_reloc_sym->unrelocated_addr = sym.st_value;
>> + map->reloc = kmap->ref_reloc_sym->addr -
>> + kmap->ref_reloc_sym->unrelocated_addr;
>> break;
>> }
>> }
>> --
>> 1.7.11.7
>
>

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