On 10/06/25 10:31 PM, Marc Zyngier wrote:
> On Tue, 10 Jun 2025 06:31:28 +0100,
> Anshuman Khandual <anshuman.khandual@xxxxxxx> wrote:
>>
>> Change MDSCR_EL1 register holding local variables as uint64_t that reflects
>> its true register width as well.
>>
>> Cc: Marc Zyngier <maz@xxxxxxxxxx>
>> Cc: Oliver Upton <oliver.upton@xxxxxxxxx>
>> Cc: Joey Gouly <joey.gouly@xxxxxxx>
>> Cc: kvm@xxxxxxxxxxxxxxx
>> Cc: kvmarm@xxxxxxxxxxxxxxx
>> Cc: linux-kernel@xxxxxxxxxxxxxxx
>> Cc: linux-kselftest@xxxxxxxxxxxxxxx
>> Cc: linux-arm-kernel@xxxxxxxxxxxxxxxxxxx
>> Reviewed-by: Ada Couprie Diaz <ada.coupriediaz@xxxxxxx>
>> Signed-off-by: Anshuman Khandual <anshuman.khandual@xxxxxxx>
>> ---
>> tools/testing/selftests/kvm/arm64/debug-exceptions.c | 4 ++--
>> 1 file changed, 2 insertions(+), 2 deletions(-)
>>
>> diff --git a/tools/testing/selftests/kvm/arm64/debug-exceptions.c b/tools/testing/selftests/kvm/arm64/debug-exceptions.c
>> index c7fb55c9135b..e34963956fbc 100644
>> --- a/tools/testing/selftests/kvm/arm64/debug-exceptions.c
>> +++ b/tools/testing/selftests/kvm/arm64/debug-exceptions.c
>> @@ -140,7 +140,7 @@ static void enable_os_lock(void)
>>
>> static void enable_monitor_debug_exceptions(void)
>> {
>> - uint32_t mdscr;
>> + uint64_t mdscr;
>>
>> asm volatile("msr daifclr, #8");
>>
>> @@ -223,7 +223,7 @@ void install_hw_bp_ctx(uint8_t addr_bp, uint8_t ctx_bp, uint64_t addr,
>>
>> static void install_ss(void)
>> {
>> - uint32_t mdscr;
>> + uint64_t mdscr;
>>
>> asm volatile("msr daifclr, #8");
>>
>
> Why change this in the place that matters *the least*?
>
> arch/arm64/kernel/debug-monitors.c is full of 32bit manipulation of
> this register, and that's only one example of it. So if you are going
> to change this, please do it fully, not as a random change in a random
> file.
The first patch in this series changes mdscr system register to 64 bit
in the mentioned file (i.e arch/arm64/kernel/debug-monitors.c).
>
> Thanks,
>
> M.
>
