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

Pull perf fixes from Ingo Molnar:
 "An uncharacteristically large number of bugs popped up in the last
  week:

   - various tooling fixes, two crashes and build problems
   - two Intel PT fixes
   - an KNL uncore driver fix
   - an Intel PMU driver fix"

* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  perf stat: Fallback to user only counters when perf_event_paranoid > 1
  perf evsel: Handle EACCESS + perf_event_paranoid=2 in fallback()
  perf evsel: Improve EPERM error handling in open_strerror()
  tools lib traceevent: Do not reassign parg after collapse_tree()
  perf probe: Check if dwarf_getlocations() is available
  perf dwarf: Guard !x86_64 definitions under #ifdef else clause
  perf tools: Use readdir() instead of deprecated readdir_r()
  perf thread_map: Use readdir() instead of deprecated readdir_r()
  perf script: Use readdir() instead of deprecated readdir_r()
  perf tools: Use readdir() instead of deprecated readdir_r()
  perf/core: Disable the event on a truncated AUX record
  perf/x86/intel/pt: Generate PMI in the STOP region as well
  perf/x86: Fix undefined shift on 32-bit kernels
  perf/x86/msr: Fix SMI overflow
  perf/x86/intel/uncore: Fix CHA registers configuration procedure for Knights Landing platform
  perf diff: Fix duplicated output column

1 files changed, 21 insertions, 2 deletions

diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c
index 738ce226002b..645dc1828836 100644
--- a/tools/perf/util/evsel.c
+++ b/tools/perf/util/evsel.c
@@ -2345,6 +2345,8 @@ out:
 bool perf_evsel__fallback(struct perf_evsel *evsel, int err,
 			  char *msg, size_t msgsize)
 {
+	int paranoid;
+
 	if ((err == ENOENT || err == ENXIO || err == ENODEV) &&
 	    evsel->attr.type   == PERF_TYPE_HARDWARE &&
 	    evsel->attr.config == PERF_COUNT_HW_CPU_CYCLES) {
@@ -2364,6 +2366,22 @@ bool perf_evsel__fallback(struct perf_evsel *evsel, int err,
 
 		zfree(&evsel->name);
 		return true;
+	} else if (err == EACCES && !evsel->attr.exclude_kernel &&
+		   (paranoid = perf_event_paranoid()) > 1) {
+		const char *name = perf_evsel__name(evsel);
+		char *new_name;
+
+		if (asprintf(&new_name, "%s%su", name, strchr(name, ':') ? "" : ":") < 0)
+			return false;
+
+		if (evsel->name)
+			free(evsel->name);
+		evsel->name = new_name;
+		scnprintf(msg, msgsize,
+"kernel.perf_event_paranoid=%d, trying to fall back to excluding kernel samples", paranoid);
+		evsel->attr.exclude_kernel = 1;
+
+		return true;
 	}
 
 	return false;
@@ -2382,12 +2400,13 @@ int perf_evsel__open_strerror(struct perf_evsel *evsel, struct target *target,
 		 "Consider tweaking /proc/sys/kernel/perf_event_paranoid,\n"
 		 "which controls use of the performance events system by\n"
 		 "unprivileged users (without CAP_SYS_ADMIN).\n\n"
-		 "The default value is 1:\n\n"
+		 "The current value is %d:\n\n"
 		 "  -1: Allow use of (almost) all events by all users\n"
 		 ">= 0: Disallow raw tracepoint access by users without CAP_IOC_LOCK\n"
 		 ">= 1: Disallow CPU event access by users without CAP_SYS_ADMIN\n"
 		 ">= 2: Disallow kernel profiling by users without CAP_SYS_ADMIN",
-				 target->system_wide ? "system-wide " : "");
+				 target->system_wide ? "system-wide " : "",
+				 perf_event_paranoid());
 	case ENOENT:
 		return scnprintf(msg, size, "The %s event is not supported.",
 				 perf_evsel__name(evsel));