[PATCH 21/37] perf jit: Do not assume pgoff is zero

From: Arnaldo Carvalho de Melo
Date: Mon Oct 24 2016 - 12:21:50 EST


From: Stefano Sanfilippo <ssanfilippo@xxxxxxxxxxxx>

When calculating .eh_frame_hdr base and LUT offsets do not always assume
that pgoff is zero.

The assumption is false for DSOs built from the jitdump by perf inject,
because the ELF header did not exist in memory at sampling time.

Signed-off-by: Stefano Sanfilippo <ssanfilippo@xxxxxxxxxxxx>
Signed-off-by: Ross McIlroy <rmcilroy@xxxxxxxxxxxx>
Reviewed-by: Stephane Eranian <eranian@xxxxxxxxxx>
Cc: Anton Blanchard <anton@xxxxxxxxxx>
Cc: Jiri Olsa <jolsa@xxxxxxxxxx>
Cc: Namhyung Kim <namhyung@xxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Link: http://lkml.kernel.org/r/1476356383-30100-6-git-send-email-eranian@xxxxxxxxxx
Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
---
tools/perf/util/unwind-libunwind-local.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/tools/perf/util/unwind-libunwind-local.c b/tools/perf/util/unwind-libunwind-local.c
index 20c2e5743903..6fec84dff3f7 100644
--- a/tools/perf/util/unwind-libunwind-local.c
+++ b/tools/perf/util/unwind-libunwind-local.c
@@ -357,8 +357,8 @@ find_proc_info(unw_addr_space_t as, unw_word_t ip, unw_proc_info_t *pi,
di.format = UNW_INFO_FORMAT_REMOTE_TABLE;
di.start_ip = map->start;
di.end_ip = map->end;
- di.u.rti.segbase = map->start + segbase;
- di.u.rti.table_data = map->start + table_data;
+ di.u.rti.segbase = map->start + segbase - map->pgoff;
+ di.u.rti.table_data = map->start + table_data - map->pgoff;
di.u.rti.table_len = fde_count * sizeof(struct table_entry)
/ sizeof(unw_word_t);
ret = dwarf_search_unwind_table(as, ip, &di, pi,
--
2.7.4