* [PATCH] softirq: Remove the unnecessary CONFIG_TRACE_IRQFLAGS
@ 2021-06-02 7:34 Yejune Deng
2021-06-02 17:53 ` Kees Cook
0 siblings, 1 reply; 3+ messages in thread
From: Yejune Deng @ 2021-06-02 7:34 UTC (permalink / raw)
To: tglx, peterz, frederic, mingo, keescook, dave; +Cc: linux-kernel, Yejune Deng
The local_irq_enable() and local_irq_disable() had two definitions that
include CONFIG_TRACE_IRQFLAGS or not.
Signed-off-by: Yejune Deng <yejunedeng@gmail.com>
---
kernel/softirq.c | 4 ----
1 file changed, 4 deletions(-)
diff --git a/kernel/softirq.c b/kernel/softirq.c
index 4992853..a81d804 100644
--- a/kernel/softirq.c
+++ b/kernel/softirq.c
@@ -362,9 +362,7 @@ void __local_bh_enable_ip(unsigned long ip, unsigned int cnt)
{
WARN_ON_ONCE(in_irq());
lockdep_assert_irqs_enabled();
-#ifdef CONFIG_TRACE_IRQFLAGS
local_irq_disable();
-#endif
/*
* Are softirqs going to be turned on now:
*/
@@ -385,9 +383,7 @@ void __local_bh_enable_ip(unsigned long ip, unsigned int cnt)
}
preempt_count_dec();
-#ifdef CONFIG_TRACE_IRQFLAGS
local_irq_enable();
-#endif
preempt_check_resched();
}
EXPORT_SYMBOL(__local_bh_enable_ip);
--
2.7.4
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [PATCH] softirq: Remove the unnecessary CONFIG_TRACE_IRQFLAGS
2021-06-02 7:34 [PATCH] softirq: Remove the unnecessary CONFIG_TRACE_IRQFLAGS Yejune Deng
@ 2021-06-02 17:53 ` Kees Cook
2021-08-10 13:59 ` Thomas Gleixner
0 siblings, 1 reply; 3+ messages in thread
From: Kees Cook @ 2021-06-02 17:53 UTC (permalink / raw)
To: Yejune Deng
Cc: tglx, peterz, frederic, mingo, dave, linux-kernel, Yejune Deng
On Wed, Jun 02, 2021 at 03:34:42PM +0800, Yejune Deng wrote:
> The local_irq_enable() and local_irq_disable() had two definitions that
> include CONFIG_TRACE_IRQFLAGS or not.
Hm, this has a behavioral change. Current code only does tracing and
raw_local_irq_disable/enable when CONFIG_TRACE_IRQFLAGS. This change
causes it to always do raw_local_irq_disable/enable. Which is the right
behavior?
-Kees
>
> Signed-off-by: Yejune Deng <yejunedeng@gmail.com>
> ---
> kernel/softirq.c | 4 ----
> 1 file changed, 4 deletions(-)
>
> diff --git a/kernel/softirq.c b/kernel/softirq.c
> index 4992853..a81d804 100644
> --- a/kernel/softirq.c
> +++ b/kernel/softirq.c
> @@ -362,9 +362,7 @@ void __local_bh_enable_ip(unsigned long ip, unsigned int cnt)
> {
> WARN_ON_ONCE(in_irq());
> lockdep_assert_irqs_enabled();
> -#ifdef CONFIG_TRACE_IRQFLAGS
> local_irq_disable();
> -#endif
> /*
> * Are softirqs going to be turned on now:
> */
> @@ -385,9 +383,7 @@ void __local_bh_enable_ip(unsigned long ip, unsigned int cnt)
> }
>
> preempt_count_dec();
> -#ifdef CONFIG_TRACE_IRQFLAGS
> local_irq_enable();
> -#endif
> preempt_check_resched();
> }
> EXPORT_SYMBOL(__local_bh_enable_ip);
> --
> 2.7.4
>
--
Kees Cook
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH] softirq: Remove the unnecessary CONFIG_TRACE_IRQFLAGS
2021-06-02 17:53 ` Kees Cook
@ 2021-08-10 13:59 ` Thomas Gleixner
0 siblings, 0 replies; 3+ messages in thread
From: Thomas Gleixner @ 2021-08-10 13:59 UTC (permalink / raw)
To: Kees Cook, Yejune Deng
Cc: peterz, frederic, mingo, dave, linux-kernel, Yejune Deng
On Wed, Jun 02 2021 at 10:53, Kees Cook wrote:
> On Wed, Jun 02, 2021 at 03:34:42PM +0800, Yejune Deng wrote:
>> The local_irq_enable() and local_irq_disable() had two definitions that
>> include CONFIG_TRACE_IRQFLAGS or not.
>
> Hm, this has a behavioral change. Current code only does tracing and
> raw_local_irq_disable/enable when CONFIG_TRACE_IRQFLAGS. This change
> causes it to always do raw_local_irq_disable/enable. Which is the right
> behavior?
Disabling interrupts is only required when CONFIG_TRACE_IRQFLAGS=y. So
the code is correct as is.
Thanks,
tglx
^ permalink raw reply [flat|nested] 3+ messages in thread
end of thread, other threads:[~2021-08-10 13:59 UTC | newest]
Thread overview: 3+ messages (download: mbox.gz / follow: Atom feed)
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2021-06-02 7:34 [PATCH] softirq: Remove the unnecessary CONFIG_TRACE_IRQFLAGS Yejune Deng
2021-06-02 17:53 ` Kees Cook
2021-08-10 13:59 ` Thomas Gleixner
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