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authorAdrian Hunter <adrian.hunter@intel.com>2018-05-22 13:54:34 +0300
committerArnaldo Carvalho de Melo <acme@redhat.com>2018-05-22 10:55:59 -0300
commit4d004365e25251002935fc3843d80934248ad3ed (patch)
tree26574a089d21977209ba4983cbae27cea5e8a042 /tools/perf/util/symbol.c
parentperf machine: Workaround missing maps for x86 PTI entry trampolines (diff)
downloadlinux-dev-4d004365e25251002935fc3843d80934248ad3ed.tar.xz
linux-dev-4d004365e25251002935fc3843d80934248ad3ed.zip
perf machine: Fix map_groups__split_kallsyms() for entry trampoline symbols
When kernel symbols are derived from /proc/kallsyms only (not using vmlinux or /proc/kcore) map_groups__split_kallsyms() is used. However that function makes assumptions that are not true with entry trampoline symbols. For now, remove the entry trampoline symbols at that point, as they are no longer needed at that point. 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/1526986485-6562-7-git-send-email-adrian.hunter@intel.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Diffstat (limited to '')
-rw-r--r--tools/perf/util/symbol.c13
1 files changed, 13 insertions, 0 deletions
diff --git a/tools/perf/util/symbol.c b/tools/perf/util/symbol.c
index 701144094183..929058da6727 100644
--- a/tools/perf/util/symbol.c
+++ b/tools/perf/util/symbol.c
@@ -737,12 +737,15 @@ static int map_groups__split_kallsyms(struct map_groups *kmaps, struct dso *dso,
struct rb_root *root = &dso->symbols;
struct rb_node *next = rb_first(root);
int kernel_range = 0;
+ bool x86_64;
if (!kmaps)
return -1;
machine = kmaps->machine;
+ x86_64 = machine__is(machine, "x86_64");
+
while (next) {
char *module;
@@ -790,6 +793,16 @@ static int map_groups__split_kallsyms(struct map_groups *kmaps, struct dso *dso,
*/
pos->start = curr_map->map_ip(curr_map, pos->start);
pos->end = curr_map->map_ip(curr_map, pos->end);
+ } else if (x86_64 && is_entry_trampoline(pos->name)) {
+ /*
+ * These symbols are not needed anymore since the
+ * trampoline maps refer to the text section and it's
+ * symbols instead. Avoid having to deal with
+ * relocations, and the assumption that the first symbol
+ * is the start of kernel text, by simply removing the
+ * symbols at this point.
+ */
+ goto discard_symbol;
} else if (curr_map != initial_map) {
char dso_name[PATH_MAX];
struct dso *ndso;