2019-10-29 12:43:04

by Xiang Zheng

Subject: [PATCH v2] arm64: print additional fault message when executing non-exec memory

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 <[email protected]>
---
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..9adec86d0f8a 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 from non-executable memory";
else
msg = "read from unreadable memory";
} else if (addr < PAGE_SIZE) {
--
2.19.1

2019-10-29 15:43:36

by Catalin Marinas

Subject: Re: [PATCH v2] arm64: print additional fault message when executing non-exec memory

On Tue, Oct 29, 2019 at 08:41:31PM +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 <[email protected]>

Queued for 5.5. Thanks.

--
Catalin

2019-10-29 19:42:37

by Will Deacon

Subject: Re: [PATCH v2] arm64: print additional fault message when executing non-exec memory

On Tue, Oct 29, 2019 at 08:41:31PM +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 <[email protected]>
> ---
> 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..9adec86d0f8a 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 from non-executable memory";
> else
> msg = "read from unreadable memory";
> } else if (addr < PAGE_SIZE) {

Acked-by: Will Deacon <[email protected]>

Will