* [PATCH] intel_idle: Fix uninitialized variable bug
@ 2020-06-24 13:19 Dan Carpenter
2020-06-24 13:41 ` Rafael J. Wysocki
0 siblings, 1 reply; 4+ messages in thread
From: Dan Carpenter @ 2020-06-24 13:19 UTC (permalink / raw)
To: Jacob Pan, Rafael J. Wysocki
Cc: Len Brown, linux-pm, linux-kernel, kernel-janitors, Kees Cook
The "tick" variable isn't initialized if "lapic_timer_always_reliable"
is true.
Fixes: 40ab82e08d78 ("intel_idle: Simplify LAPIC timer reliability checks")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
---
drivers/idle/intel_idle.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/idle/intel_idle.c b/drivers/idle/intel_idle.c
index aae53e650638..6c9152f303a6 100644
--- a/drivers/idle/intel_idle.c
+++ b/drivers/idle/intel_idle.c
@@ -132,7 +132,7 @@ static __cpuidle int intel_idle(struct cpuidle_device *dev,
struct cpuidle_state *state = &drv->states[index];
unsigned long eax = flg2MWAIT(state->flags);
unsigned long ecx = 1; /* break on interrupt flag */
- bool tick;
+ bool tick = false;
int cpu = smp_processor_id();
/*
--
2.27.0
^ permalink raw reply related [flat|nested] 4+ messages in thread* Re: [PATCH] intel_idle: Fix uninitialized variable bug
2020-06-24 13:19 [PATCH] intel_idle: Fix uninitialized variable bug Dan Carpenter
@ 2020-06-24 13:41 ` Rafael J. Wysocki
2020-06-25 9:04 ` Dan Carpenter
0 siblings, 1 reply; 4+ messages in thread
From: Rafael J. Wysocki @ 2020-06-24 13:41 UTC (permalink / raw)
To: Dan Carpenter
Cc: Jacob Pan, Rafael J. Wysocki, Len Brown, Linux PM,
Linux Kernel Mailing List, kernel-janitors, Kees Cook
On Wed, Jun 24, 2020 at 3:19 PM Dan Carpenter <dan.carpenter@oracle.com> wrote:
>
> The "tick" variable isn't initialized if "lapic_timer_always_reliable"
> is true.
If lapic_timer_always_reliable is true, then
static_cpu_has(X86_FEATURE_ARAT) must also be true AFAICS.
So the lapic_timer_always_reliable check in there looks redundant.
> Fixes: 40ab82e08d78 ("intel_idle: Simplify LAPIC timer reliability checks")
> Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
> ---
> drivers/idle/intel_idle.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/idle/intel_idle.c b/drivers/idle/intel_idle.c
> index aae53e650638..6c9152f303a6 100644
> --- a/drivers/idle/intel_idle.c
> +++ b/drivers/idle/intel_idle.c
> @@ -132,7 +132,7 @@ static __cpuidle int intel_idle(struct cpuidle_device *dev,
> struct cpuidle_state *state = &drv->states[index];
> unsigned long eax = flg2MWAIT(state->flags);
> unsigned long ecx = 1; /* break on interrupt flag */
> - bool tick;
> + bool tick = false;
> int cpu = smp_processor_id();
>
> /*
> --
^ permalink raw reply [flat|nested] 4+ messages in thread* Re: [PATCH] intel_idle: Fix uninitialized variable bug
2020-06-24 13:41 ` Rafael J. Wysocki
@ 2020-06-25 9:04 ` Dan Carpenter
2020-06-25 10:37 ` Rafael J. Wysocki
0 siblings, 1 reply; 4+ messages in thread
From: Dan Carpenter @ 2020-06-25 9:04 UTC (permalink / raw)
To: Rafael J. Wysocki
Cc: Jacob Pan, Rafael J. Wysocki, Len Brown, Linux PM,
Linux Kernel Mailing List, kernel-janitors, Kees Cook
On Wed, Jun 24, 2020 at 03:41:05PM +0200, Rafael J. Wysocki wrote:
> On Wed, Jun 24, 2020 at 3:19 PM Dan Carpenter <dan.carpenter@oracle.com> wrote:
> >
> > The "tick" variable isn't initialized if "lapic_timer_always_reliable"
> > is true.
>
> If lapic_timer_always_reliable is true, then
> static_cpu_has(X86_FEATURE_ARAT) must also be true AFAICS.
>
> So the lapic_timer_always_reliable check in there looks redundant.
Can the lapic_timer_always_reliable variable just be removed entirely
and replaced with an static_cpu_has(X86_FEATURE_ARAT) check?
regards,
dan carpenter
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH] intel_idle: Fix uninitialized variable bug
2020-06-25 9:04 ` Dan Carpenter
@ 2020-06-25 10:37 ` Rafael J. Wysocki
0 siblings, 0 replies; 4+ messages in thread
From: Rafael J. Wysocki @ 2020-06-25 10:37 UTC (permalink / raw)
To: Dan Carpenter
Cc: Rafael J. Wysocki, Jacob Pan, Rafael J. Wysocki, Len Brown,
Linux PM, Linux Kernel Mailing List, kernel-janitors, Kees Cook
On Thu, Jun 25, 2020 at 11:05 AM Dan Carpenter <dan.carpenter@oracle.com> wrote:
>
> On Wed, Jun 24, 2020 at 03:41:05PM +0200, Rafael J. Wysocki wrote:
> > On Wed, Jun 24, 2020 at 3:19 PM Dan Carpenter <dan.carpenter@oracle.com> wrote:
> > >
> > > The "tick" variable isn't initialized if "lapic_timer_always_reliable"
> > > is true.
> >
> > If lapic_timer_always_reliable is true, then
> > static_cpu_has(X86_FEATURE_ARAT) must also be true AFAICS.
> >
> > So the lapic_timer_always_reliable check in there looks redundant.
>
> Can the lapic_timer_always_reliable variable just be removed entirely
> and replaced with an static_cpu_has(X86_FEATURE_ARAT) check?
Yes, it can.
See https://patchwork.kernel.org/patch/11623309/
Thanks!
^ permalink raw reply [flat|nested] 4+ messages in thread
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2020-06-24 13:19 [PATCH] intel_idle: Fix uninitialized variable bug Dan Carpenter
2020-06-24 13:41 ` Rafael J. Wysocki
2020-06-25 9:04 ` Dan Carpenter
2020-06-25 10:37 ` Rafael J. Wysocki
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