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Subject: Re: [PATCH] csky: uprobes: Restore thread.trap_no
Reply-To: loongson-kernel@lists.loongnix.cn
References: <1682213987-3708-1-git-send-email-yangtiezhu@loongson.cn>
To:     Guo Ren <guoren@kernel.org>
Cc:     linux-csky@vger.kernel.org, linux-kernel@vger.kernel.org,
        loongson-kernel@lists.loongnix.cn, Oleg Nesterov <oleg@redhat.com>,
        Srikar Dronamraju <srikar@linux.vnet.ibm.com>
From:   Tiezhu Yang <yangtiezhu@loongson.cn>
Message-ID: <cdacf9d8-cf59-bf4e-5379-0b5bfc03a4e2@loongson.cn>
Date:   Mon, 24 Apr 2023 19:47:13 +0800
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Cc:
Oleg Nesterov <oleg@redhat.com>
Srikar Dronamraju <srikar@linux.vnet.ibm.com>

On 04/23/2023 09:39 AM, Tiezhu Yang wrote:
> thread.trap_no is saved in arch_uprobe_pre_xol(), it should be restored
> in arch_uprobe_{post,abort}_xol() accordingly, otherwise the save operation
> is meaningless, this change is similar with x86 and powerpc.
>
> Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
> ---
>  arch/csky/kernel/probes/uprobes.c | 2 ++
>  1 file changed, 2 insertions(+)
>
> diff --git a/arch/csky/kernel/probes/uprobes.c b/arch/csky/kernel/probes/uprobes.c
> index 2d31a12..6277f2b 100644
> --- a/arch/csky/kernel/probes/uprobes.c
> +++ b/arch/csky/kernel/probes/uprobes.c
> @@ -64,6 +64,7 @@ int arch_uprobe_post_xol(struct arch_uprobe *auprobe, struct pt_regs *regs)
>  	struct uprobe_task *utask = current->utask;
>
>  	WARN_ON_ONCE(current->thread.trap_no != UPROBE_TRAP_NR);
> +	current->thread.trap_no = utask->autask.saved_trap_no;
>
>  	instruction_pointer_set(regs, utask->vaddr + auprobe->insn_size);
>
> @@ -101,6 +102,7 @@ void arch_uprobe_abort_xol(struct arch_uprobe *auprobe, struct pt_regs *regs)
>  {
>  	struct uprobe_task *utask = current->utask;
>
> +	current->thread.trap_no = utask->autask.saved_trap_no;
>  	/*
>  	 * Task has received a fatal signal, so reset back to probed
>  	 * address.
>

Hi Oleg and Srikar,

Could you please review this patch, thank you.

Thanks,
Tiezhu