lkml.org 
[lkml]   [2018]   [May]   [16]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
Date
From
Subject[tip:perf/core] perf tools: Use the "_stest" symbol to identify the kernel map when loading kcore
Commit-ID:  5654997838c2ac9b1950d633fc97f354cc4180e7
Gitweb: https://git.kernel.org/tip/5654997838c2ac9b1950d633fc97f354cc4180e7
Author: Adrian Hunter <adrian.hunter@intel.com>
AuthorDate: Wed, 9 May 2018 14:43:34 +0300
Committer: Arnaldo Carvalho de Melo <acme@redhat.com>
CommitDate: Tue, 15 May 2018 14:31:25 -0300

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 <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Joerg Roedel <joro@8bytes.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
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 <acme@redhat.com>
---
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;
+ }
}
}

\
 
 \ /
  Last update: 2018-05-16 20:06    [W:0.855 / U:3.164 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site