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perf callchain: Separate eh/debug frame offset cache. 

Commit f1f13af99a ("perf callchain: Cache eh/debug frame offset for
dwarf unwind") introduces a cache for .debug_frame and .eh_frame_hdr.
Unfortunately, it makes them share a same cache (dso->frame_offset).
Which causes unwind failure on ARM:

   $ perf test unwind
  Test dwarf unwind: FAILED!

The reason is that, if a dso has '.debug_frame' but doesn't have
'.eh_frame_hdr' (like ARM), dso->frame_offset will be filled by offset
of '.debug_frame' during the first time calling of find_proc_info() ->
read_unwind_spec_debug_frame(), and be regarded to '.eh_frame_hdr' when
the second time calling of find_proc_info() ->
read_unwind_spec_eh_frame(), since '.eh_frame_hdr' is checked prior to
'.debug_frame'.

This patch solves the problem by creating two cache fields for
'.eh_frame_hdr' and '.debug_frame'.

Signed-off-by: Wang Nan <wangnan0@huawei.com>
Acked-by: Jiri Olsa <jolsa@redhat.com>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Cc: Li Zefan <lizefan@huawei.com>
Link: http://lkml.kernel.org/r/55028BA0.1030701@huawei.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
hifive-unleashed-5.1
Wang Nan 2015-03-13 15:02:56 +08:00 committed by Arnaldo Carvalho de Melo
parent 1312c8a8fb
commit 303cb89a6d
2 changed files with 6 additions and 5 deletions
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3
tools/perf/util/dso.h
View File

@ -139,7 +139,8 @@ struct dso {
u32 status_seen;
size_t file_size;
struct list_head open_entry;
u64 frame_offset;
u64 debug_frame_offset;
u64 eh_frame_hdr_offset;
} data;
union { /* Tool specific area */

8
tools/perf/util/unwind-libunwind.c
View File

@ -266,7 +266,7 @@ static int read_unwind_spec_eh_frame(struct dso *dso, struct machine *machine,
u64 *fde_count)
{
int ret = -EINVAL, fd;
u64 offset = dso->data.frame_offset;
u64 offset = dso->data.eh_frame_hdr_offset;
if (offset == 0) {
fd = dso__data_fd(dso, machine);
@ -275,7 +275,7 @@ static int read_unwind_spec_eh_frame(struct dso *dso, struct machine *machine,
/* Check the .eh_frame section for unwinding info */
offset = elf_section_offset(fd, ".eh_frame_hdr");
dso->data.frame_offset = offset;
dso->data.eh_frame_hdr_offset = offset;
}
if (offset)
@ -291,7 +291,7 @@ static int read_unwind_spec_debug_frame(struct dso *dso,
struct machine *machine, u64 *offset)
{
int fd;
u64 ofs = dso->data.frame_offset;
u64 ofs = dso->data.debug_frame_offset;
if (ofs == 0) {
fd = dso__data_fd(dso, machine);
@ -300,7 +300,7 @@ static int read_unwind_spec_debug_frame(struct dso *dso,
/* Check the .debug_frame section for unwinding info */
ofs = elf_section_offset(fd, ".debug_frame");
dso->data.frame_offset = ofs;
dso->data.debug_frame_offset = ofs;
}
*offset = ofs;