| Message ID | 20170731183728.61087-1-mka@chromium.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
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 <ard.biesheuvel@linaro.org> 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 > --- > 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 >
On Tue, Aug 01, 2017 at 12:12:23PM +0100, Mark Rutland wrote: > 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 <ard.biesheuvel@linaro.org> > 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? Hi Mark, picked as a fix with the above tags. Thanks. -- Daniel
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);
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> --- drivers/clocksource/arm_arch_timer.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)