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Message-ID: <61e636e0-9dac-fa9a-7a4f-aa50a336505f@huawei.com>
Date:   Fri, 21 Oct 2022 23:19:30 +0800
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Subject: Re: [PATCH -next] csky: add arch support current_stack_pointer
To:     Guo Ren <guoren@kernel.org>
CC:     <linux-csky@vger.kernel.org>, <linux-kernel@vger.kernel.org>,
        <wangkefeng.wang@huawei.com>, Guohanjun <guohanjun@huawei.com>
References: <20221021115654.5278-1-tongtiangen@huawei.com>
 <CAJF2gTQN9j=cXLTgUp++438b2acqNoZF0r_D_9xFdaxUEc3c-w@mail.gmail.com>
From:   Tong Tiangen <tongtiangen@huawei.com>
In-Reply-To: <CAJF2gTQN9j=cXLTgUp++438b2acqNoZF0r_D_9xFdaxUEc3c-w@mail.gmail.com>
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在 2022/10/21 22:48, Guo Ren 写道:
> On Fri, Oct 21, 2022 at 7:31 PM Tong Tiangen <tongtiangen@huawei.com> wrote:
>>
>> To follow the existing per-arch conventions, using "current_stack_pointer"
>> to set sp.
>>
>> This will let it be used in non-arch places(like HARDENED_USERCOPY).
>>
> 
> Add a Link tag here. The original patch series lore.kernel.org link.
> One tip: commit fdecfea09328b33fd08a4d418237cce9fd176d69 riscv: Rename
> "sp_in_global" to "current_stack_pointer"
> 
>      To follow the existing per-arch conventions, rename "sp_in_global" to
>      "current_stack_pointer". This will let it be used in non-arch places
>      (like HARDENED_USERCOPY).

Hi guo:

Ok, Will be added in v2.

Thanks.
Tong.

>> Signed-off-by: Tong Tiangen <tongtiangen@huawei.com>
>> ---
>>   arch/csky/Kconfig                 | 1 +
>>   arch/csky/include/asm/processor.h | 2 ++
>>   arch/csky/kernel/stacktrace.c     | 6 ++----
>>   3 files changed, 5 insertions(+), 4 deletions(-)
>>
>> diff --git a/arch/csky/Kconfig b/arch/csky/Kconfig
>> index adee6ab36862..2236b5c0c213 100644
>> --- a/arch/csky/Kconfig
>> +++ b/arch/csky/Kconfig
>> @@ -9,6 +9,7 @@ config CSKY
>>          select ARCH_USE_BUILTIN_BSWAP
>>          select ARCH_USE_QUEUED_RWLOCKS
>>          select ARCH_USE_QUEUED_SPINLOCKS
>> +       select ARCH_HAS_CURRENT_STACK_POINTER
>>          select ARCH_INLINE_READ_LOCK if !PREEMPTION
>>          select ARCH_INLINE_READ_LOCK_BH if !PREEMPTION
>>          select ARCH_INLINE_READ_LOCK_IRQ if !PREEMPTION
>> diff --git a/arch/csky/include/asm/processor.h b/arch/csky/include/asm/processor.h
>> index 63ad71fab30d..ea75d72dea86 100644
>> --- a/arch/csky/include/asm/processor.h
>> +++ b/arch/csky/include/asm/processor.h
>> @@ -84,4 +84,6 @@ unsigned long __get_wchan(struct task_struct *p);
>>
>>   #define cpu_relax() barrier()
>>
>> +register unsigned long current_stack_pointer __asm__("sp");
>> +
>>   #endif /* __ASM_CSKY_PROCESSOR_H */
>> diff --git a/arch/csky/kernel/stacktrace.c b/arch/csky/kernel/stacktrace.c
>> index 9f78f5d21511..27ecd63e321b 100644
>> --- a/arch/csky/kernel/stacktrace.c
>> +++ b/arch/csky/kernel/stacktrace.c
>> @@ -23,10 +23,9 @@ void notrace walk_stackframe(struct task_struct *task, struct pt_regs *regs,
>>                  sp = user_stack_pointer(regs);
>>                  pc = instruction_pointer(regs);
>>          } else if (task == NULL || task == current) {
>> -               const register unsigned long current_sp __asm__ ("sp");
>>                  const register unsigned long current_fp __asm__ ("r8");
>>                  fp = current_fp;
>> -               sp = current_sp;
>> +               sp = current_stack_pointer;
>>                  pc = (unsigned long)walk_stackframe;
>>          } else {
>>                  /* task blocked in __switch_to */
>> @@ -68,8 +67,7 @@ static void notrace walk_stackframe(struct task_struct *task,
>>                  sp = user_stack_pointer(regs);
>>                  pc = instruction_pointer(regs);
>>          } else if (task == NULL || task == current) {
>> -               const register unsigned long current_sp __asm__ ("sp");
>> -               sp = current_sp;
>> +               sp = current_stack_pointer;
>>                  pc = (unsigned long)walk_stackframe;
>>          } else {
>>                  /* task blocked in __switch_to */
>> --
>> 2.25.1
>>
> 
>