* [PATCH 1/1] ARM: hw_breakpoint: Do not directly check the event's overflow_handler hook
@ 2021-02-07 10:59 Zhen Lei
2021-02-07 13:05 ` Leizhen (ThunderTown)
2021-02-12 10:02 ` Will Deacon
0 siblings, 2 replies; 6+ messages in thread
From: Zhen Lei @ 2021-02-07 10:59 UTC (permalink / raw)
To: Will Deacon, Mark Rutland, Russell King, linux-arm-kernel
Cc: Wang Nan, Zhen Lei
The commit 1879445dfa7b ("perf/core: Set event's default
::overflow_handler()") set a default event->overflow_handler in
perf_event_alloc(), and replace the check event->overflow_handler with
is_default_overflow_handler(), but one is missing.
Currently, the bp->overflow_handler can not be NULL. As a result,
enable_single_step() is always not invoked.
Fixes: 1879445dfa7b ("perf/core: Set event's default ::overflow_handler()")
Signed-off-by: Zhen Lei <thunder.leizhen@huawei.com>
Cc: Wang Nan <wangnan0@huawei.com>
---
arch/arm/kernel/hw_breakpoint.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/arch/arm/kernel/hw_breakpoint.c b/arch/arm/kernel/hw_breakpoint.c
index 08660ae9dcbce1c..b1423fb130ea4a0 100644
--- a/arch/arm/kernel/hw_breakpoint.c
+++ b/arch/arm/kernel/hw_breakpoint.c
@@ -886,7 +886,7 @@ static void breakpoint_handler(unsigned long unknown, struct pt_regs *regs)
info->trigger = addr;
pr_debug("breakpoint fired: address = 0x%x\n", addr);
perf_bp_event(bp, regs);
- if (!bp->overflow_handler)
+ if (is_default_overflow_handler(bp))
enable_single_step(bp, addr);
goto unlock;
}
--
1.8.3
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^ permalink raw reply related [flat|nested] 6+ messages in thread* Re: [PATCH 1/1] ARM: hw_breakpoint: Do not directly check the event's overflow_handler hook
2021-02-07 10:59 [PATCH 1/1] ARM: hw_breakpoint: Do not directly check the event's overflow_handler hook Zhen Lei
@ 2021-02-07 13:05 ` Leizhen (ThunderTown)
2021-02-12 10:02 ` Will Deacon
1 sibling, 0 replies; 6+ messages in thread
From: Leizhen (ThunderTown) @ 2021-02-07 13:05 UTC (permalink / raw)
To: Will Deacon, Mark Rutland, Russell King, linux-arm-kernel; +Cc: Wang Nan
On 2021/2/7 18:59, Zhen Lei wrote:
> The commit 1879445dfa7b ("perf/core: Set event's default
> ::overflow_handler()") set a default event->overflow_handler in
> perf_event_alloc(), and replace the check event->overflow_handler with
> is_default_overflow_handler(), but one is missing.
>
> Currently, the bp->overflow_handler can not be NULL. As a result,
> enable_single_step() is always not invoked.
Our test case use "perf record -e mem:$TEST_LOC_ADDR:x -p $TEST_PID sleep 10" to track
the invocation of a test function, the entry address of the function is $TEST_LOC_ADDR.
This function was called only once. Therefore, the sampling result of perf should be one，
as follow:
[ perf record: Captured and wrote 0.001 MB perf.data (1 samples) ]
But it's actually infinite.
[ perf record: Captured and wrote 135.426 MB perf.data (2068004 samples) ]
If sleep 10 is not specified, OOM will be reported.
>
> Fixes: 1879445dfa7b ("perf/core: Set event's default ::overflow_handler()")
> Signed-off-by: Zhen Lei <thunder.leizhen@huawei.com>
> Cc: Wang Nan <wangnan0@huawei.com>
> ---
> arch/arm/kernel/hw_breakpoint.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/arch/arm/kernel/hw_breakpoint.c b/arch/arm/kernel/hw_breakpoint.c
> index 08660ae9dcbce1c..b1423fb130ea4a0 100644
> --- a/arch/arm/kernel/hw_breakpoint.c
> +++ b/arch/arm/kernel/hw_breakpoint.c
> @@ -886,7 +886,7 @@ static void breakpoint_handler(unsigned long unknown, struct pt_regs *regs)
> info->trigger = addr;
> pr_debug("breakpoint fired: address = 0x%x\n", addr);
> perf_bp_event(bp, regs);
> - if (!bp->overflow_handler)
> + if (is_default_overflow_handler(bp))
> enable_single_step(bp, addr);
> goto unlock;
> }
>
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^ permalink raw reply [flat|nested] 6+ messages in thread* Re: [PATCH 1/1] ARM: hw_breakpoint: Do not directly check the event's overflow_handler hook
2021-02-07 10:59 [PATCH 1/1] ARM: hw_breakpoint: Do not directly check the event's overflow_handler hook Zhen Lei
2021-02-07 13:05 ` Leizhen (ThunderTown)
@ 2021-02-12 10:02 ` Will Deacon
2021-02-18 2:03 ` Leizhen (ThunderTown)
1 sibling, 1 reply; 6+ messages in thread
From: Will Deacon @ 2021-02-12 10:02 UTC (permalink / raw)
To: Zhen Lei; +Cc: Mark Rutland, Wang Nan, Russell King, linux-arm-kernel
On Sun, Feb 07, 2021 at 06:59:34PM +0800, Zhen Lei wrote:
> The commit 1879445dfa7b ("perf/core: Set event's default
> ::overflow_handler()") set a default event->overflow_handler in
> perf_event_alloc(), and replace the check event->overflow_handler with
> is_default_overflow_handler(), but one is missing.
>
> Currently, the bp->overflow_handler can not be NULL. As a result,
> enable_single_step() is always not invoked.
>
> Fixes: 1879445dfa7b ("perf/core: Set event's default ::overflow_handler()")
> Signed-off-by: Zhen Lei <thunder.leizhen@huawei.com>
> Cc: Wang Nan <wangnan0@huawei.com>
> ---
> arch/arm/kernel/hw_breakpoint.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/arch/arm/kernel/hw_breakpoint.c b/arch/arm/kernel/hw_breakpoint.c
> index 08660ae9dcbce1c..b1423fb130ea4a0 100644
> --- a/arch/arm/kernel/hw_breakpoint.c
> +++ b/arch/arm/kernel/hw_breakpoint.c
> @@ -886,7 +886,7 @@ static void breakpoint_handler(unsigned long unknown, struct pt_regs *regs)
> info->trigger = addr;
> pr_debug("breakpoint fired: address = 0x%x\n", addr);
> perf_bp_event(bp, regs);
> - if (!bp->overflow_handler)
> + if (is_default_overflow_handler(bp))
> enable_single_step(bp, addr);
> goto unlock;
> }
Acked-by: Will Deacon <will@kernel.org>
Please can you put this into the patch tracker?
https://www.arm.linux.org.uk/developer/patches/
Will
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^ permalink raw reply [flat|nested] 6+ messages in thread* Re: [PATCH 1/1] ARM: hw_breakpoint: Do not directly check the event's overflow_handler hook
2021-02-12 10:02 ` Will Deacon
@ 2021-02-18 2:03 ` Leizhen (ThunderTown)
2021-02-18 9:13 ` Will Deacon
0 siblings, 1 reply; 6+ messages in thread
From: Leizhen (ThunderTown) @ 2021-02-18 2:03 UTC (permalink / raw)
To: Will Deacon; +Cc: Mark Rutland, Wang Nan, Russell King, linux-arm-kernel
On 2021/2/12 18:02, Will Deacon wrote:
> On Sun, Feb 07, 2021 at 06:59:34PM +0800, Zhen Lei wrote:
>> The commit 1879445dfa7b ("perf/core: Set event's default
>> ::overflow_handler()") set a default event->overflow_handler in
>> perf_event_alloc(), and replace the check event->overflow_handler with
>> is_default_overflow_handler(), but one is missing.
>>
>> Currently, the bp->overflow_handler can not be NULL. As a result,
>> enable_single_step() is always not invoked.
>>
>> Fixes: 1879445dfa7b ("perf/core: Set event's default ::overflow_handler()")
>> Signed-off-by: Zhen Lei <thunder.leizhen@huawei.com>
>> Cc: Wang Nan <wangnan0@huawei.com>
>> ---
>> arch/arm/kernel/hw_breakpoint.c | 2 +-
>> 1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/arch/arm/kernel/hw_breakpoint.c b/arch/arm/kernel/hw_breakpoint.c
>> index 08660ae9dcbce1c..b1423fb130ea4a0 100644
>> --- a/arch/arm/kernel/hw_breakpoint.c
>> +++ b/arch/arm/kernel/hw_breakpoint.c
>> @@ -886,7 +886,7 @@ static void breakpoint_handler(unsigned long unknown, struct pt_regs *regs)
>> info->trigger = addr;
>> pr_debug("breakpoint fired: address = 0x%x\n", addr);
>> perf_bp_event(bp, regs);
>> - if (!bp->overflow_handler)
>> + if (is_default_overflow_handler(bp))
>> enable_single_step(bp, addr);
>> goto unlock;
>> }
>
> Acked-by: Will Deacon <will@kernel.org>
>
> Please can you put this into the patch tracker?
>
> https://www.arm.linux.org.uk/developer/patches/
I've added it.
https://www.arm.linux.org.uk/developer/patches/viewpatch.php?id=9064/1
>
> Will
>
> .
>
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^ permalink raw reply [flat|nested] 6+ messages in thread* Re: [PATCH 1/1] ARM: hw_breakpoint: Do not directly check the event's overflow_handler hook
2021-02-18 2:03 ` Leizhen (ThunderTown)
@ 2021-02-18 9:13 ` Will Deacon
2021-02-18 10:56 ` Leizhen (ThunderTown)
0 siblings, 1 reply; 6+ messages in thread
From: Will Deacon @ 2021-02-18 9:13 UTC (permalink / raw)
To: Leizhen (ThunderTown)
Cc: Mark Rutland, Wang Nan, Russell King, linux-arm-kernel
On Thu, Feb 18, 2021 at 10:03:22AM +0800, Leizhen (ThunderTown) wrote:
>
>
> On 2021/2/12 18:02, Will Deacon wrote:
> > On Sun, Feb 07, 2021 at 06:59:34PM +0800, Zhen Lei wrote:
> >> The commit 1879445dfa7b ("perf/core: Set event's default
> >> ::overflow_handler()") set a default event->overflow_handler in
> >> perf_event_alloc(), and replace the check event->overflow_handler with
> >> is_default_overflow_handler(), but one is missing.
> >>
> >> Currently, the bp->overflow_handler can not be NULL. As a result,
> >> enable_single_step() is always not invoked.
> >>
> >> Fixes: 1879445dfa7b ("perf/core: Set event's default ::overflow_handler()")
> >> Signed-off-by: Zhen Lei <thunder.leizhen@huawei.com>
> >> Cc: Wang Nan <wangnan0@huawei.com>
> >> ---
> >> arch/arm/kernel/hw_breakpoint.c | 2 +-
> >> 1 file changed, 1 insertion(+), 1 deletion(-)
> >>
> >> diff --git a/arch/arm/kernel/hw_breakpoint.c b/arch/arm/kernel/hw_breakpoint.c
> >> index 08660ae9dcbce1c..b1423fb130ea4a0 100644
> >> --- a/arch/arm/kernel/hw_breakpoint.c
> >> +++ b/arch/arm/kernel/hw_breakpoint.c
> >> @@ -886,7 +886,7 @@ static void breakpoint_handler(unsigned long unknown, struct pt_regs *regs)
> >> info->trigger = addr;
> >> pr_debug("breakpoint fired: address = 0x%x\n", addr);
> >> perf_bp_event(bp, regs);
> >> - if (!bp->overflow_handler)
> >> + if (is_default_overflow_handler(bp))
> >> enable_single_step(bp, addr);
> >> goto unlock;
> >> }
> >
> > Acked-by: Will Deacon <will@kernel.org>
> >
> > Please can you put this into the patch tracker?
> >
> > https://www.arm.linux.org.uk/developer/patches/
>
> I've added it.
>
> https://www.arm.linux.org.uk/developer/patches/viewpatch.php?id=9064/1
Thanks, although you forgot to add my Ack!
Will
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^ permalink raw reply [flat|nested] 6+ messages in thread* Re: [PATCH 1/1] ARM: hw_breakpoint: Do not directly check the event's overflow_handler hook
2021-02-18 9:13 ` Will Deacon
@ 2021-02-18 10:56 ` Leizhen (ThunderTown)
0 siblings, 0 replies; 6+ messages in thread
From: Leizhen (ThunderTown) @ 2021-02-18 10:56 UTC (permalink / raw)
To: Will Deacon; +Cc: Mark Rutland, Wang Nan, Russell King, linux-arm-kernel
On 2021/2/18 17:13, Will Deacon wrote:
> On Thu, Feb 18, 2021 at 10:03:22AM +0800, Leizhen (ThunderTown) wrote:
>>
>>
>> On 2021/2/12 18:02, Will Deacon wrote:
>>> On Sun, Feb 07, 2021 at 06:59:34PM +0800, Zhen Lei wrote:
>>>> The commit 1879445dfa7b ("perf/core: Set event's default
>>>> ::overflow_handler()") set a default event->overflow_handler in
>>>> perf_event_alloc(), and replace the check event->overflow_handler with
>>>> is_default_overflow_handler(), but one is missing.
>>>>
>>>> Currently, the bp->overflow_handler can not be NULL. As a result,
>>>> enable_single_step() is always not invoked.
>>>>
>>>> Fixes: 1879445dfa7b ("perf/core: Set event's default ::overflow_handler()")
>>>> Signed-off-by: Zhen Lei <thunder.leizhen@huawei.com>
>>>> Cc: Wang Nan <wangnan0@huawei.com>
>>>> ---
>>>> arch/arm/kernel/hw_breakpoint.c | 2 +-
>>>> 1 file changed, 1 insertion(+), 1 deletion(-)
>>>>
>>>> diff --git a/arch/arm/kernel/hw_breakpoint.c b/arch/arm/kernel/hw_breakpoint.c
>>>> index 08660ae9dcbce1c..b1423fb130ea4a0 100644
>>>> --- a/arch/arm/kernel/hw_breakpoint.c
>>>> +++ b/arch/arm/kernel/hw_breakpoint.c
>>>> @@ -886,7 +886,7 @@ static void breakpoint_handler(unsigned long unknown, struct pt_regs *regs)
>>>> info->trigger = addr;
>>>> pr_debug("breakpoint fired: address = 0x%x\n", addr);
>>>> perf_bp_event(bp, regs);
>>>> - if (!bp->overflow_handler)
>>>> + if (is_default_overflow_handler(bp))
>>>> enable_single_step(bp, addr);
>>>> goto unlock;
>>>> }
>>>
>>> Acked-by: Will Deacon <will@kernel.org>
>>>
>>> Please can you put this into the patch tracker?
>>>
>>> https://www.arm.linux.org.uk/developer/patches/
>>
>> I've added it.
>>
>> https://www.arm.linux.org.uk/developer/patches/viewpatch.php?id=9064/1
>
> Thanks, although you forgot to add my Ack!
Sorry, the first time I operated this web, the patch in the attachment
can no longer be updated. I just mentioned it in the new "Node".
>
> Will
>
> .
>
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^ permalink raw reply [flat|nested] 6+ messages in thread
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2021-02-07 10:59 [PATCH 1/1] ARM: hw_breakpoint: Do not directly check the event's overflow_handler hook Zhen Lei
2021-02-07 13:05 ` Leizhen (ThunderTown)
2021-02-12 10:02 ` Will Deacon
2021-02-18 2:03 ` Leizhen (ThunderTown)
2021-02-18 9:13 ` Will Deacon
2021-02-18 10:56 ` Leizhen (ThunderTown)
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