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Commit 303cb89a authored by Wang Nan's avatar Wang Nan Committed by Arnaldo Carvalho de Melo
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perf callchain: Separate eh/debug frame offset cache. 



Commit f1f13af9 ("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: default avatarWang Nan <wangnan0@huawei.com>
Acked-by: default avatarJiri Olsa <jolsa@redhat.com>
Acked-by: default avatarNamhyung Kim <namhyung@kernel.org>
Cc: Li Zefan <lizefan@huawei.com>
Link: http://lkml.kernel.org/r/55028BA0.1030701@huawei.com


Signed-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
parent 1312c8a8

tools/perf/util/dso.h

+2 −1
Original line number Diff line number Diff line
@@ -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 */

tools/perf/util/unwind-libunwind.c

+4 −4
Original line number Diff line number Diff line
@@ -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;