[PATCH 4.7 055/143] perf symbols: Fix annotation of objects with debuginfo files

From: Greg Kroah-Hartman
Date: Mon Sep 05 2016 - 12:50:29 EST


4.7-stable review patch. If anyone has any objections, please let me know.

------------------

From: Anton Blanchard <anton@xxxxxxxxx>

commit 50de1a0c54cdbc69a6dbcbc323f53daf95a4050e upstream.

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.

Signed-off-by: Anton Blanchard <anton@xxxxxxxxx>
Reviewed-by: Naveen N. Rao <naveen.n.rao@xxxxxxxxxxxxxxxxxx>
Tested-by: Wang Nan <wangnan0@xxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Ravi Bangoria <ravi.bangoria@xxxxxxxxxxxxxxxxxx>
Fixes: 73cdf0c6ea9c ("perf symbols: Record text offset in dso to calculate objdump address")
Link: http://lkml.kernel.org/r/20160813115533.6de17912@kryten
Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
tools/perf/util/symbol-elf.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

--- a/tools/perf/util/symbol-elf.c
+++ b/tools/perf/util/symbol-elf.c
@@ -827,7 +827,8 @@ int dso__load_sym(struct dso *dso, struc
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)