diff options
| author | Knut Petersen <Knut_Petersen@t-online.de> | 2013-09-25 14:29:37 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2014-06-11 12:03:27 -0700 |
| commit | 02f98e3e36da106338b7c732fed516420fb20e2a (patch) | |
| tree | 1b4a7ae28473392c448f81a2de59900357cc4dec | |
| parent | a4a108e8d7fba75a2dbfbe0818a3a4dec79d6d57 (diff) | |
perf: Enforce 1 as lower limit for perf_event_max_sample_rate
commit 723478c8a471403c53cf144999701f6e0c4bbd11 upstream.
/proc/sys/kernel/perf_event_max_sample_rate will accept
negative values as well as 0.
Negative values are unreasonable, and 0 causes a
divide by zero exception in perf_proc_update_handler.
This patch enforces a lower limit of 1.
Signed-off-by: Knut Petersen <Knut_Petersen@t-online.de>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/5242DB0C.4070005@t-online.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Weng Meiling <wengmeiling.weng@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | kernel/events/core.c | 2 | ||||
| -rw-r--r-- | kernel/sysctl.c | 1 |
2 files changed, 2 insertions, 1 deletions
diff --git a/kernel/events/core.c b/kernel/events/core.c index bffea4900db..459b94c9472 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -190,7 +190,7 @@ int perf_proc_update_handler(struct ctl_table *table, int write, void __user *buffer, size_t *lenp, loff_t *ppos) { - int ret = proc_dointvec(table, write, buffer, lenp, ppos); + int ret = proc_dointvec_minmax(table, write, buffer, lenp, ppos); if (ret || !write) return ret; diff --git a/kernel/sysctl.c b/kernel/sysctl.c index f1fa5538610..9469f4c61a3 100644 --- a/kernel/sysctl.c +++ b/kernel/sysctl.c @@ -1049,6 +1049,7 @@ static struct ctl_table kern_table[] = { .maxlen = sizeof(sysctl_perf_event_sample_rate), .mode = 0644, .proc_handler = perf_proc_update_handler, + .extra1 = &one, }, { .procname = "perf_cpu_time_max_percent", |