Merge branch 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip

* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (25 commits)
  perf: Fix SIGIO handling
  perf top: Don't stop if no kernel symtab is found
  perf top: Handle kptr_restrict
  perf top: Remove unused macro
  perf events: initialize fd array to -1 instead of 0
  perf tools: Make sure kptr_restrict warnings fit 80 col terms
  perf tools: Fix build on older systems
  perf symbols: Handle /proc/sys/kernel/kptr_restrict
  perf: Remove duplicate headers
  ftrace: Add internal recursive checks
  tracing: Update btrfs's tracepoints to use u64 interface
  tracing: Add __print_symbolic_u64 to avoid warnings on 32bit machine
  ftrace: Set ops->flag to enabled even on static function tracing
  tracing: Have event with function tracer check error return
  ftrace: Have ftrace_startup() return failure code
  jump_label: Check entries limit in __jump_label_update
  ftrace/recordmcount: Avoid STT_FUNC symbols as base on ARM
  scripts/tags.sh: Add magic for trace-events for etags too
  scripts/tags.sh: Fix ctags for DEFINE_EVENT()
  x86/ftrace: Fix compiler warning in ftrace.c
  ...

1 files changed, 6 insertions, 2 deletions

diff --git a/tools/perf/util/header.c b/tools/perf/util/header.c
index 0717beb..afb0849 100644
--- a/tools/perf/util/header.c
+++ b/tools/perf/util/header.c
@@ -193,9 +193,13 @@ int build_id_cache__add_s(const char *sbuild_id, const char *debugdir,
 	     *linkname = malloc(size), *targetname;
 	int len, err = -1;
 
-	if (is_kallsyms)
+	if (is_kallsyms) {
+		if (symbol_conf.kptr_restrict) {
+			pr_debug("Not caching a kptr_restrict'ed /proc/kallsyms\n");
+			return 0;
+		}
 		realname = (char *)name;
-	else
+	} else
 		realname = realpath(name, NULL);
 
 	if (realname == NULL || filename == NULL || linkname == NULL)