Re: [RESEND PATCH V2] arm64: fault: avoid send SIGBUS two times

From: Xie XiuQi
Date: Mon Dec 11 2017 - 22:31:54 EST


Hi Dongjiu,

On 2017/12/12 0:05, Dongjiu Geng wrote:
> do_sea() calls arm64_notify_die() which will always signal
> user-space. It also returns whether APEI claimed the external
> abort as a RAS notification. If it returns failure do_mem_abort()
> will signal user-space too.
>
> do_mem_abort() wants to know if we handled the error, we always
> call arm64_notify_die() so can always return success.
>
> Signed-off-by: Dongjiu Geng <gengdongjiu@xxxxxxxxxx>
> ---
> 1. Address James's comments to update the commit messages
> 2. Address James's comments to not change the si_code for SIGBUS
> ---
> arch/arm64/mm/fault.c | 7 +++----
> 1 file changed, 3 insertions(+), 4 deletions(-)
>
> diff --git a/arch/arm64/mm/fault.c b/arch/arm64/mm/fault.c
> index b64958b..38b9f3e 100644
> --- a/arch/arm64/mm/fault.c
> +++ b/arch/arm64/mm/fault.c
> @@ -610,7 +610,6 @@ static int do_sea(unsigned long addr, unsigned int esr, struct pt_regs *regs)
> {
> struct siginfo info;
> const struct fault_info *inf;
> - int ret = 0;
>
> inf = esr_to_fault_info(esr);
> pr_err("Synchronous External Abort: %s (0x%08x) at 0x%016lx\n",
> @@ -625,7 +624,7 @@ static int do_sea(unsigned long addr, unsigned int esr, struct pt_regs *regs)
> if (interrupts_enabled(regs))
> nmi_enter();
>
> - ret = ghes_notify_sea();
> + ghes_notify_sea();
>
> if (interrupts_enabled(regs))
> nmi_exit();
> @@ -640,7 +639,7 @@ static int do_sea(unsigned long addr, unsigned int esr, struct pt_regs *regs)
> info.si_addr = (void __user *)addr;
> arm64_notify_die("", regs, &info, esr);
>
> - return ret;
> + return 0;

It looks good to me. do_sea() has done all necessary action for SEA, so it should always return 0,
no matter ghes_notify_sea() return true or false.

Reviewed-by: Xie XiuQi <xiexiuqi@xxxxxxxxxx>

> }
>
> static const struct fault_info fault_info[] = {
> --
> 2.10.1
>

--
Thanks,
Xie XiuQi