Thread (3 messages) 3 messages, 3 authors, 2017-08-01

[PATCH] clocksource: arm_arch_timer: Fix mem frame loop initialization

From: mark.rutland@arm.com (Mark Rutland)
Date: 2017-08-01 11:13:32
Also in: lkml

On Mon, Jul 31, 2017 at 11:37:28AM -0700, Matthias Kaehlcke wrote:
The loop to find the best memory frame in arch_timer_mem_acpi_init()
initializes the loop counter with itself ('i = i'), which is suspicious
in the first place and pointed out by clang. The loop condition is
'i < timer_count' and a prior for loop exits when 'i' reaches
'timer_count', therefore the second loop is never executed.

Initialize the loop counter with 0 to iterate over all timers, which
supposedly was the intention before the typo monster attacked.

Fixes: c2743a36765d3 ("clocksource: arm_arch_timer: add GTDT support for memory-mapped timer")
Signed-off-by: Matthias Kaehlcke <mka@chromium.org>
Ard also spotted this issue [1], along with another issue we still need
to solve. In the mean time it would be nice to have this fixed, so:

Reported-by: Ard Biesheuvel <redacted> 
Acked-by: Mark Rutland <mark.rutland@arm.com>

Daniel, Thomas,

Could one of you please pick this up as a fix, with the above tags?

Thanks,
Mark.

[1] http://lists.infradead.org/pipermail/linux-arm-kernel/2017-July/520779.html
quoted hunk ↗ jump to hunk
---
 drivers/clocksource/arm_arch_timer.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/clocksource/arm_arch_timer.c b/drivers/clocksource/arm_arch_timer.c
index aae87c4c546e..72bbfccef113 100644
--- a/drivers/clocksource/arm_arch_timer.c
+++ b/drivers/clocksource/arm_arch_timer.c
@@ -1440,7 +1440,7 @@ static int __init arch_timer_mem_acpi_init(int platform_timer_count)
 	 * While unlikely, it's theoretically possible that none of the frames
 	 * in a timer expose the combination of feature we want.
 	 */
-	for (i = i; i < timer_count; i++) {
+	for (i = 0; i < timer_count; i++) {
 		timer = &timers[i];
 
 		frame = arch_timer_mem_find_best_frame(timer);
-- 
2.14.0.rc0.400.g1c36432dff-goog
Keyboard shortcuts
hback out one level
jnext message in thread
kprevious message in thread
ldrill in
Escclose help / fold thread tree
?toggle this help