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authorLinus Torvalds <torvalds@linux-foundation.org>2019-02-03 08:59:51 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2019-02-03 08:59:51 -0800
commit58f6d4287af751a75b24f4d32e6e1b077146ab18 (patch)
treee6bf85d9645dc1a0e54ef30d02cee65d0507e339 /kernel
parent89401be6580eab6419bab1f553144131e7a335dc (diff)
parentd3c8c0af7565ae5b4f9e65cff6e824ee2acdd451 (diff)
downloadlinux-58f6d4287af751a75b24f4d32e6e1b077146ab18.tar.gz
Merge branch 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull perf fixes from Thomas Gleixner:
 "A pile of perf updates:

   - Fix broken sanity check in the /proc/sys/kernel/perf_cpu_time_max_percent
     write handler

   - Cure a perf script crash which caused by an unitinialized data
     structure

   - Highlight the hottest instruction in perf top and not a random one

   - Cure yet another clang issue when building perf python

   - Handle topology entries with no CPU correctly in the tools

   - Handle perf data which contains both tracepoints and performance
     counter entries correctly.

   - Add a missing NULL pointer check in perf ordered_events_free()"

* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  perf script: Fix crash when processing recorded stat data
  perf top: Fix wrong hottest instruction highlighted
  perf tools: Handle TOPOLOGY headers with no CPU
  perf python: Remove -fstack-clash-protection when building with some clang versions
  perf core: Fix perf_proc_update_handler() bug
  perf script: Fix crash with printing mixed trace point and other events
  perf ordered_events: Fix crash in ordered_events__free
Diffstat (limited to 'kernel')
-rw-r--r--kernel/events/core.c14
1 files changed, 7 insertions, 7 deletions
diff --git a/kernel/events/core.c b/kernel/events/core.c
index 3cd13a30f732..e5ede6918050 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -436,18 +436,18 @@ int perf_proc_update_handler(struct ctl_table *table, int write,
 		void __user *buffer, size_t *lenp,
 		loff_t *ppos)
 {
-	int ret = proc_dointvec_minmax(table, write, buffer, lenp, ppos);
-
-	if (ret || !write)
-		return ret;
-
+	int ret;
+	int perf_cpu = sysctl_perf_cpu_time_max_percent;
 	/*
 	 * If throttling is disabled don't allow the write:
 	 */
-	if (sysctl_perf_cpu_time_max_percent == 100 ||
-	    sysctl_perf_cpu_time_max_percent == 0)
+	if (write && (perf_cpu == 100 || perf_cpu == 0))
 		return -EINVAL;
 
+	ret = proc_dointvec_minmax(table, write, buffer, lenp, ppos);
+	if (ret || !write)
+		return ret;
+
 	max_samples_per_tick = DIV_ROUND_UP(sysctl_perf_event_sample_rate, HZ);
 	perf_sample_period_ns = NSEC_PER_SEC / sysctl_perf_event_sample_rate;
 	update_perf_cpu_limits();