From 5baecbcd9c9a2f491afe1369fc22e7363f9c94d5 Mon Sep 17 00:00:00 2001 From: Dima Kogan Date: Mon, 7 Sep 2015 17:34:19 -0700 Subject: [PATCH] perf symbols: we can now read separate debug-info files based on a build ID Recent GDB (at least on a vanilla Debian box) looks for debug information in /usr/lib/debug/.build-id/nn/nnnnnnn where nn/nnnnnn is the build-id of the stripped ELF binary. This is documented here: https://sourceware.org/gdb/onlinedocs/gdb/Separate-Debug-Files.html This was not working in perf because we didn't read the build id until AFTER we searched for the separate debug information file. This patch reads the build ID and THEN does the search. Signed-off-by: Dima Kogan Link: http://lkml.kernel.org/r/87si6pfwz4.fsf@secretsauce.net Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/util/symbol.c | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/tools/perf/util/symbol.c b/tools/perf/util/symbol.c index e7bf0c46918d..71bf711a628c 100644 --- a/tools/perf/util/symbol.c +++ b/tools/perf/util/symbol.c @@ -1406,6 +1406,7 @@ int dso__load(struct dso *dso, struct map *map, symbol_filter_t filter) struct symsrc ss_[2]; struct symsrc *syms_ss = NULL, *runtime_ss = NULL; bool kmod; + unsigned char build_id[BUILD_ID_SIZE]; pthread_mutex_lock(&dso->lock); @@ -1461,6 +1462,14 @@ int dso__load(struct dso *dso, struct map *map, symbol_filter_t filter) dso->symtab_type == DSO_BINARY_TYPE__GUEST_KMODULE || dso->symtab_type == DSO_BINARY_TYPE__GUEST_KMODULE_COMP; + + /* + * Read the build id if possible. This is required for + * DSO_BINARY_TYPE__BUILDID_DEBUGINFO to work + */ + if (filename__read_build_id(dso->name, build_id, BUILD_ID_SIZE) > 0) + dso__set_build_id(dso, build_id); + /* * Iterate over candidate debug images. * Keep track of "interesting" ones (those which have a symtab, dynsym, -- 2.39.5