From 5654997838c2ac9b1950d633fc97f354cc4180e7 Mon Sep 17 00:00:00 2001 From: Adrian Hunter Date: Wed, 9 May 2018 14:43:34 +0300 Subject: [PATCH] perf tools: Use the "_stest" symbol to identify the kernel map when loading kcore The first symbol is not necessarily in the kernel text. Instead of using the first symbol, use the _stest symbol to identify the kernel map when loading kcore. This allows for the introduction of symbols to identify the x86_64 PTI entry trampolines. Signed-off-by: Adrian Hunter Cc: Alexander Shishkin Cc: Andi Kleen Cc: Andy Lutomirski Cc: Dave Hansen Cc: H. Peter Anvin Cc: Jiri Olsa Cc: Joerg Roedel Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: x86@kernel.org Link: http://lkml.kernel.org/r/1525866228-30321-6-git-send-email-adrian.hunter@intel.com Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/util/symbol.c | 16 ++++++++-------- 1 file changed, 8 insertions(+), 8 deletions(-) diff --git a/tools/perf/util/symbol.c b/tools/perf/util/symbol.c index f48dc157c2bd..4a39f4d0a174 100644 --- a/tools/perf/util/symbol.c +++ b/tools/perf/util/symbol.c @@ -1149,7 +1149,7 @@ static int dso__load_kcore(struct dso *dso, struct map *map, bool is_64_bit; int err, fd; char kcore_filename[PATH_MAX]; - struct symbol *sym; + u64 stext; if (!kmaps) return -EINVAL; @@ -1198,13 +1198,13 @@ static int dso__load_kcore(struct dso *dso, struct map *map, old_map = next; } - /* Find the kernel map using the first symbol */ - sym = dso__first_symbol(dso); - list_for_each_entry(new_map, &md.maps, node) { - if (sym && sym->start >= new_map->start && - sym->start < new_map->end) { - replacement_map = new_map; - break; + /* Find the kernel map using the '_stext' symbol */ + if (!kallsyms__get_function_start(kallsyms_filename, "_stext", &stext)) { + list_for_each_entry(new_map, &md.maps, node) { + if (stext >= new_map->start && stext < new_map->end) { + replacement_map = new_map; + break; + } } } -- 2.30.2