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References: <20221021115654.5278-1-tongtiangen@huawei.com>
In-Reply-To: <20221021115654.5278-1-tongtiangen@huawei.com>
From:   Guo Ren <guoren@kernel.org>
Date:   Fri, 21 Oct 2022 22:48:07 +0800
Message-ID: <CAJF2gTQN9j=cXLTgUp++438b2acqNoZF0r_D_9xFdaxUEc3c-w@mail.gmail.com>
Subject: Re: [PATCH -next] csky: add arch support current_stack_pointer
To:     Tong Tiangen <tongtiangen@huawei.com>
Cc:     linux-csky@vger.kernel.org, linux-kernel@vger.kernel.org,
        wangkefeng.wang@huawei.com, Guohanjun <guohanjun@huawei.com>
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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).
> 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
>


-- 
Best Regards
 Guo Ren