Re: [PATCH 18/24] alpha: select SYSCTL_EXCEPTION_TRACE

[Magnus Lindholm]

Hi Matt,

On Tue, Sep 1, 2026 at 5:51 PM Matt Turner <mattst88@xxxxxxxxx> wrote:
>
> Report unhandled user faults the way other architectures do, and hook up
> the debug.exception-trace sysctl that controls the reporting.
>
> The message gives the faulting address, the PC and the user stack
> pointer, and is rate limited.
>
> Assisted-by: Claude:claude-opus-5
> Signed-off-by: Matt Turner <mattst88@xxxxxxxxx>
> ---

I tested this on an Alpha UP2000. With debug.exception-trace=1,
unhandled SEGV_MAPERR and SEGV_ACCERR faults produced the expected
"unmapped access" and "access violation" messages.

With debug.exception-trace=0, both processes still received SIGSEGV,
but no additional messages were written to the kernel log.

Tested-by: Magnus Lindholm <linmag7@xxxxxxxxx>
Reviewed-by: Magnus Lindholm <linmag7@xxxxxxxxx>