Re: [PATCH] arm64: print additional fault message when executing non-exec memory

From: Xiang Zheng
Date: Mon Oct 28 2019 - 21:10:06 EST




On 2019/10/29 0:41, Will Deacon wrote:
> On Mon, Oct 28, 2019 at 05:08:37PM +0800, Xiang Zheng wrote:
>> When attempting to executing non-executable memory, the fault message
>> shows:
>>
>> Unable to handle kernel read from unreadable memory at virtual address
>> ffff802dac469000
>>
>> This may confuse someone, so add a new fault message for instruction
>> abort.
>>
>> Signed-off-by: Xiang Zheng <zhengxiang9@xxxxxxxxxx>
>> ---
>> arch/arm64/mm/fault.c | 2 ++
>> 1 file changed, 2 insertions(+)
>>
>> diff --git a/arch/arm64/mm/fault.c b/arch/arm64/mm/fault.c
>> index 9fc6db0bcbad..68bf4ec376d0 100644
>> --- a/arch/arm64/mm/fault.c
>> +++ b/arch/arm64/mm/fault.c
>> @@ -318,6 +318,8 @@ static void __do_kernel_fault(unsigned long addr, unsigned int esr,
>> if (is_el1_permission_fault(addr, esr, regs)) {
>> if (esr & ESR_ELx_WNR)
>> msg = "write to read-only memory";
>> + else if (is_el1_instruction_abort(esr))
>> + msg = "execute non-executable memory";
>
> nit, please make this "execute from non-executable memory".

Thanks, I will make this in the next version of patch.

>
> With that:
>
> Acked-by: Will Deacon <will@xxxxxxxxxx>
>
> Will
>
> .
>

--

Thanks,
Xiang