diff options
| author | Jisheng Zhang <jszhang@marvell.com> | 2015-10-20 10:02:34 +0200 |
|---|---|---|
| committer | Daniel Lezcano <daniel.lezcano@linaro.org> | 2015-10-27 01:32:33 +0100 |
| commit | d6df3576e6b4bcf765f5ace69915b4fa4a7ee1c3 (patch) | |
| tree | 0ab04e90271ba7f74b0247bfaf93b5fb4f61330f | |
| parent | timekeeping: Increment clock_was_set_seq in timekeeping_init() (diff) | |
| download | linux-d6df3576e6b4bcf765f5ace69915b4fa4a7ee1c3.tar.xz linux-d6df3576e6b4bcf765f5ace69915b4fa4a7ee1c3.zip | |
clocksource/drivers/arm_global_timer: Prevent ftrace recursion
Currently arm_global_timer can be used as a scheduler clock. We properly
marked gt_sched_clock_read() as notrace but we then call another function
gt_counter_read() that _wasn't_ notrace.
Having a traceable function in the sched_clock() path leads to a recursion
within ftrace and a kernel crash.
Fix this by adding an extra notrace function to keep other users of
gt_counter_read() traceable.
Signed-off-by: Jisheng Zhang <jszhang@marvell.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
| -rw-r--r-- | drivers/clocksource/arm_global_timer.c | 9 |
1 files changed, 7 insertions, 2 deletions
diff --git a/drivers/clocksource/arm_global_timer.c b/drivers/clocksource/arm_global_timer.c index 29ea50ac366a..a2cb6fae9295 100644 --- a/drivers/clocksource/arm_global_timer.c +++ b/drivers/clocksource/arm_global_timer.c @@ -60,7 +60,7 @@ static struct clock_event_device __percpu *gt_evt; * different to the 32-bit upper value read previously, go back to step 2. * Otherwise the 64-bit timer counter value is correct. */ -static u64 gt_counter_read(void) +static u64 notrace _gt_counter_read(void) { u64 counter; u32 lower; @@ -79,6 +79,11 @@ static u64 gt_counter_read(void) return counter; } +static u64 gt_counter_read(void) +{ + return _gt_counter_read(); +} + /** * To ensure that updates to comparator value register do not set the * Interrupt Status Register proceed as follows: @@ -201,7 +206,7 @@ static struct clocksource gt_clocksource = { #ifdef CONFIG_CLKSRC_ARM_GLOBAL_TIMER_SCHED_CLOCK static u64 notrace gt_sched_clock_read(void) { - return gt_counter_read(); + return _gt_counter_read(); } #endif |