Re: [PATCH] arm64: traps: Mark kernel as tainted on SError panic

[Will Deacon <will@kernel.org>]

On Thu, Jul 10, 2025 at 03:46:35AM -0700, Breno Leitao wrote:
> Set TAINT_MACHINE_CHECK when SError interrupts trigger a panic to
> flag potential hardware faults. This tainting mechanism aids in
> debugging and enables correlation of hardware-related crashes in
> large-scale deployments.
> 
> This change aligns with similar patches[1] that mark machine check
> events when the system crashes due to hardware errors.
> 
> Link: https://lore.kernel.org/all/20250702-add_tain-v1-1-9187b10914b9@debian.org/ [1]
> Signed-off-by: Breno Leitao <leitao@debian.org>
> ---
>  arch/arm64/kernel/traps.c | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/arch/arm64/kernel/traps.c b/arch/arm64/kernel/traps.c
> index 9bfa5c944379d..7468b22585cef 100644
> --- a/arch/arm64/kernel/traps.c
> +++ b/arch/arm64/kernel/traps.c
> @@ -931,6 +931,7 @@ void __noreturn panic_bad_stack(struct pt_regs *regs, unsigned long esr, unsigne
>  
>  void __noreturn arm64_serror_panic(struct pt_regs *regs, unsigned long esr)
>  {
> +	add_taint(TAINT_MACHINE_CHECK, LOCKDEP_STILL_OK);
>  	console_verbose();
>  
>  	pr_crit("SError Interrupt on CPU%d, code 0x%016lx -- %s\n",

If we're going to taint for SError, shouldn't we also taint for an
unclaimed SEA?

Will