perf callchain: Separate eh/debug frame offset cache. (303cb89a) · Commits · 戴 / test

Commit ("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>

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;

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