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, 10 insertions, 0 deletions

diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c
index 0974f957b8fa..8e2c85798185 100644
--- a/tools/perf/builtin-record.c
+++ b/tools/perf/builtin-record.c
@@ -823,6 +823,16 @@ int cmd_record(int argc, const char **argv, const char *prefix __used)
 
 	symbol__init();
 
+	if (symbol_conf.kptr_restrict)
+		pr_warning(
+"WARNING: Kernel address maps (/proc/{kallsyms,modules}) are restricted,\n"
+"check /proc/sys/kernel/kptr_restrict.\n\n"
+"Samples in kernel functions may not be resolved if a suitable vmlinux\n"
+"file is not found in the buildid cache or in the vmlinux path.\n\n"
+"Samples in kernel modules won't be resolved at all.\n\n"
+"If some relocation was applied (e.g. kexec) symbols may be misresolved\n"
+"even with a suitable vmlinux or kallsyms file.\n\n");
+
 	if (no_buildid_cache || no_buildid)
 		disable_buildid_cache();