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Date:   Mon, 10 Oct 2022 19:24:15 +0800
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Subject: Re: [PATCH v3] ARM: mm: Provide better message when kernel fault
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To:     Russell King <linux@armlinux.org.uk>
CC:     <linux-arm-kernel@lists.infradead.org>,
        <linux-kernel@vger.kernel.org>
References: <YzF7X2PBdps2MaG/@shell.armlinux.org.uk>
 <20220927062134.99019-1-wangkefeng.wang@huawei.com>
From:   Kefeng Wang <wangkefeng.wang@huawei.com>
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On 2022/9/27 14:21, Kefeng Wang wrote:
> If there is a kernel fault, see do_kernel_fault(), we only print
> the generic "paging request" or "NULL pointer dereference" message
> which don't show read, write or excute information, let's provide
> better fault message for them.

Hi Russell, what's your option about this one, if no object,

I will send to ARM patch system, thanks,

> Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
> ---
> v3: show the infos in die_kernel_fault()
>   arch/arm/mm/fault.c | 5 +++--
>   1 file changed, 3 insertions(+), 2 deletions(-)
>
> diff --git a/arch/arm/mm/fault.c b/arch/arm/mm/fault.c
> index 46cccd6bf705..f8fe0ec64c23 100644
> --- a/arch/arm/mm/fault.c
> +++ b/arch/arm/mm/fault.c
> @@ -111,8 +111,9 @@ static void die_kernel_fault(const char *msg, struct mm_struct *mm,
>   {
>   	bust_spinlocks(1);
>   	pr_alert("8<--- cut here ---\n");
> -	pr_alert("Unable to handle kernel %s at virtual address %08lx\n",
> -		 msg, addr);
> +	pr_alert("Unable to handle kernel %s at virtual address %08lx when %s\n",
> +		 msg, addr, fsr & FSR_LNX_PF ? "execute" :
> +		 fsr & FSR_WRITE ? "write" : "read");
>   
>   	show_pte(KERN_ALERT, mm, addr);
>   	die("Oops", regs, fsr);