perf: Enforce 1 as lower limit for perf_event_max_sample_rate

/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>

1 files changed, 1 insertions, 1 deletions

diff --git a/kernel/events/core.c b/kernel/events/core.c
index d49a9d29334c..b25d65ce7106 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -193,7 +193,7 @@ 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;