On 11/12/20 9:39 AM, Catalin Marinas wrote:
> On Tue, Nov 10, 2020 at 11:10:29PM +0100, Andrey Konovalov wrote:
>> diff --git a/arch/arm64/kernel/mte.c b/arch/arm64/kernel/mte.c
>> index 664c968dc43c..dbda6598c19d 100644
>> --- a/arch/arm64/kernel/mte.c
>> +++ b/arch/arm64/kernel/mte.c
>> @@ -129,6 +131,26 @@ void *mte_set_mem_tag_range(void *addr, size_t size, u8
>> tag)
>> return ptr;
>> }
>>
>> +void mte_init_tags(u64 max_tag)
>> +{
>> + static bool gcr_kernel_excl_initialized = false;
>> +
>> + if (!gcr_kernel_excl_initialized) {
>> + /*
>> + * The format of the tags in KASAN is 0xFF and in MTE is 0xF.
>> + * This conversion extracts an MTE tag from a KASAN tag.
>> + */
>> + u64 incl = GENMASK(FIELD_GET(MTE_TAG_MASK >> MTE_TAG_SHIFT,
>> + max_tag), 0);
>> +
>> + gcr_kernel_excl = ~incl & SYS_GCR_EL1_EXCL_MASK;
>> + gcr_kernel_excl_initialized = true;
>> + }
>> +
>> + /* Enable the kernel exclude mask for random tags generation. */
>> + write_sysreg_s(SYS_GCR_EL1_RRND | gcr_kernel_excl, SYS_GCR_EL1);
>> +}
>
> I don't think this function belongs to this patch. There is an earlier
> patch that talks about mte_init_tags() but no trace of it until this
> patch.
>
Could you please point out to which patch are you referring to?
--
Regards,
Vincenzo
