Re: [PATCH 4.19 BACKPORT] arm64: debug: Don't propagate UNKNOWN FAR into si_code for debug signals

[Greg KH]

On Wed, Apr 03, 2019 at 11:34:08AM +0100, Will Deacon wrote:
> Commit b9a4b9d084d978f80eb9210727c81804588b42ff upstream.
> 
> FAR_EL1 is UNKNOWN for all debug exceptions other than those caused by
> taking a hardware watchpoint. Unfortunately, if a debug handler returns
> a non-zero value, then we will propagate the UNKNOWN FAR value to
> userspace via the si_addr field of the SIGTRAP siginfo_t.
> 
> Instead, let's set si_addr to take on the PC of the faulting instruction,
> which we have available in the current pt_regs.
> 
> Cc: <stable@xxxxxxxxxxxxxxx> # 4.19.y
> Reviewed-by: Mark Rutland <mark.rutland@xxxxxxx>
> Signed-off-by: Will Deacon <will.deacon@xxxxxxx>
> Signed-off-by: Catalin Marinas <catalin.marinas@xxxxxxx>
> ---
>  arch/arm64/mm/fault.c | 9 +++++----
>  1 file changed, 5 insertions(+), 4 deletions(-)

Thanks for all 5 of these patches, now queued up.

greg k-h