From: "Shi, Yang" <yang.shi@linaro.org>
To: Catalin Marinas <catalin.marinas@arm.com>
Cc: rostedt@goodmis.org, will.deacon@arm.com, dave.long@linaro.org,
panand@redhat.com, linaro-kernel@lists.linaro.org,
linux-kernel@vger.kernel.org,
linux-arm-kernel@lists.infradead.org,
linux-rt-users@vger.kernel.org
Subject: Re: [PATCH] arm64: replace read_lock to rcu lock in call_break_hook
Date: Thu, 01 Oct 2015 09:03:05 -0700 [thread overview]
Message-ID: <560D5939.7080107@linaro.org> (raw)
In-Reply-To: <20151001150735.GH6963@e104818-lin.cambridge.arm.com>
On 10/1/2015 8:07 AM, Catalin Marinas wrote:
> On Wed, Sep 30, 2015 at 03:59:04PM -0700, Yang Shi wrote:
>> diff --git a/arch/arm64/kernel/debug-monitors.c b/arch/arm64/kernel/debug-monitors.c
>> index cebf786..eb520d0 100644
>> --- a/arch/arm64/kernel/debug-monitors.c
>> +++ b/arch/arm64/kernel/debug-monitors.c
>> @@ -292,11 +292,11 @@ static int call_break_hook(struct pt_regs *regs, unsigned int esr)
>> struct break_hook *hook;
>> int (*fn)(struct pt_regs *regs, unsigned int esr) = NULL;
>>
>> - read_lock(&break_hook_lock);
>> + rcu_read_lock();
>> list_for_each_entry(hook, &break_hook, node)
>> if ((esr & hook->esr_mask) == hook->esr_val)
>> fn = hook->fn;
>> - read_unlock(&break_hook_lock);
>> + rcu_read_unlock();
>>
>> return fn ? fn(regs, esr) : DBG_HOOK_ERROR;
>> }
>
> That's not enough, you also need list_(add|del)_rcu where the list is
> modified, together with list_for_each_entry_rcu() here.
Thanks for pointing it out. I'm going to prepare v2 with list_(add|del)_rcu.
Yang
>
WARNING: multiple messages have this Message-ID (diff)
From: yang.shi@linaro.org (Shi, Yang)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH] arm64: replace read_lock to rcu lock in call_break_hook
Date: Thu, 01 Oct 2015 09:03:05 -0700 [thread overview]
Message-ID: <560D5939.7080107@linaro.org> (raw)
In-Reply-To: <20151001150735.GH6963@e104818-lin.cambridge.arm.com>
On 10/1/2015 8:07 AM, Catalin Marinas wrote:
> On Wed, Sep 30, 2015 at 03:59:04PM -0700, Yang Shi wrote:
>> diff --git a/arch/arm64/kernel/debug-monitors.c b/arch/arm64/kernel/debug-monitors.c
>> index cebf786..eb520d0 100644
>> --- a/arch/arm64/kernel/debug-monitors.c
>> +++ b/arch/arm64/kernel/debug-monitors.c
>> @@ -292,11 +292,11 @@ static int call_break_hook(struct pt_regs *regs, unsigned int esr)
>> struct break_hook *hook;
>> int (*fn)(struct pt_regs *regs, unsigned int esr) = NULL;
>>
>> - read_lock(&break_hook_lock);
>> + rcu_read_lock();
>> list_for_each_entry(hook, &break_hook, node)
>> if ((esr & hook->esr_mask) == hook->esr_val)
>> fn = hook->fn;
>> - read_unlock(&break_hook_lock);
>> + rcu_read_unlock();
>>
>> return fn ? fn(regs, esr) : DBG_HOOK_ERROR;
>> }
>
> That's not enough, you also need list_(add|del)_rcu where the list is
> modified, together with list_for_each_entry_rcu() here.
Thanks for pointing it out. I'm going to prepare v2 with list_(add|del)_rcu.
Yang
>
next prev parent reply other threads:[~2015-10-01 16:03 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-09-30 22:59 [PATCH] arm64: replace read_lock to rcu lock in call_break_hook Yang Shi
2015-09-30 22:59 ` Yang Shi
2015-10-01 15:07 ` Catalin Marinas
2015-10-01 15:07 ` Catalin Marinas
2015-10-01 16:03 ` Shi, Yang [this message]
2015-10-01 16:03 ` Shi, Yang
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