Re: [PATCH v4 13/18] kasan: arm64: x86: Handle int3 for inline KASAN reports

[Maciej Wieczor-Retman]

On 2025-08-13 at 15:49:15 +0100, Ada Couprie Diaz wrote:
>Hi,
>
>On 12/08/2025 14:23, Maciej Wieczor-Retman wrote:
>> [...]
>> 
>> Make part of that hook - which decides whether to die or recover from a
>> tag mismatch - arch independent to avoid duplicating a long comment on
>> both x86 and arm64 architectures.
>> 
>> Signed-off-by: Maciej Wieczor-Retman <maciej.wieczor-retman@xxxxxxxxx>
>> ---
>> [...]
>> diff --git a/arch/arm64/kernel/traps.c b/arch/arm64/kernel/traps.c
>> index f528b6041f6a..b9bdabc14ad1 100644
>> --- a/arch/arm64/kernel/traps.c
>> +++ b/arch/arm64/kernel/traps.c
>> @@ -1068,22 +1068,7 @@ int kasan_brk_handler(struct pt_regs *regs, unsigned long esr)
>>   	kasan_report(addr, size, write, pc);
>> -	/*
>> -	 * The instrumentation allows to control whether we can proceed after
>> -	 * a crash was detected. This is done by passing the -recover flag to
>> -	 * the compiler. Disabling recovery allows to generate more compact
>> -	 * code.
>> -	 *
>> -	 * Unfortunately disabling recovery doesn't work for the kernel right
>> -	 * now. KASAN reporting is disabled in some contexts (for example when
>> -	 * the allocator accesses slab object metadata; this is controlled by
>> -	 * current->kasan_depth). All these accesses are detected by the tool,
>> -	 * even though the reports for them are not printed.
>> -	 *
>> -	 * This is something that might be fixed at some point in the future.
>> -	 */
>> -	if (!recover)
>> -		die("Oops - KASAN", regs, esr);
>> +	kasan_inline_recover(recover, "Oops - KASAN", regs, esr);
>It seems that `die` is missing as the last argument, otherwise
>CONFIG_KASAN_SW_TAGS will not build on arm64.
>With the fix, it builds fully without further issues.
>
>Thanks,
>Ada

Oh right, thank you!

-- 
Kind regards
Maciej Wieczór-Retman