[PATCH] powerpc: add support for TIF_NOTIFY_SIGNAL

[Michael Ellerman]

Jens Axboe <axboe at kernel.dk> writes:
> Wire up TIF_NOTIFY_SIGNAL handling for powerpc.
>
> Cc: linuxppc-dev at lists.ozlabs.org
> Signed-off-by: Jens Axboe <axboe at kernel.dk>
> ---
>
> 5.11 has support queued up for TIF_NOTIFY_SIGNAL, see this posting
> for details:
>
> https://lore.kernel.org/io-uring/20201026203230.386348-1-axboe@kernel.dk/
>
> As part of that work, I'm adding TIF_NOTIFY_SIGNAL support to all archs,
> as that will enable a set of cleanups once all of them support it. I'm
> happy carrying this patch if need be, or it can be funelled through the
> arch tree. Let me know.

Happy for you to take it along with the rest of the series.

Acked-by: Michael Ellerman <mpe at ellerman.id.au>


cheers

> diff --git a/arch/powerpc/include/asm/thread_info.h b/arch/powerpc/include/asm/thread_info.h
> index 46a210b03d2b..53115ae61495 100644
> --- a/arch/powerpc/include/asm/thread_info.h
> +++ b/arch/powerpc/include/asm/thread_info.h
> @@ -90,6 +90,7 @@ void arch_setup_new_exec(void);
>  #define TIF_SYSCALL_TRACE	0	/* syscall trace active */
>  #define TIF_SIGPENDING		1	/* signal pending */
>  #define TIF_NEED_RESCHED	2	/* rescheduling necessary */
> +#define TIF_NOTIFY_SIGNAL	3	/* signal notifications exist */
>  #define TIF_SYSCALL_EMU		4	/* syscall emulation active */
>  #define TIF_RESTORE_TM		5	/* need to restore TM FP/VEC/VSX */
>  #define TIF_PATCH_PENDING	6	/* pending live patching update */
> @@ -115,6 +116,7 @@ void arch_setup_new_exec(void);
>  #define _TIF_SYSCALL_TRACE	(1<<TIF_SYSCALL_TRACE)
>  #define _TIF_SIGPENDING		(1<<TIF_SIGPENDING)
>  #define _TIF_NEED_RESCHED	(1<<TIF_NEED_RESCHED)
> +#define _TIF_NOTIFY_SIGNAL	(1<<TIF_NOTIFY_SIGNAL)
>  #define _TIF_POLLING_NRFLAG	(1<<TIF_POLLING_NRFLAG)
>  #define _TIF_32BIT		(1<<TIF_32BIT)
>  #define _TIF_RESTORE_TM		(1<<TIF_RESTORE_TM)
> @@ -136,7 +138,8 @@ void arch_setup_new_exec(void);
>  
>  #define _TIF_USER_WORK_MASK	(_TIF_SIGPENDING | _TIF_NEED_RESCHED | \
>  				 _TIF_NOTIFY_RESUME | _TIF_UPROBE | \
> -				 _TIF_RESTORE_TM | _TIF_PATCH_PENDING)
> +				 _TIF_RESTORE_TM | _TIF_PATCH_PENDING | \
> +				 _TIF_NOTIFY_SIGNAL)
>  #define _TIF_PERSYSCALL_MASK	(_TIF_RESTOREALL|_TIF_NOERROR)
>  
>  /* Bits in local_flags */
> diff --git a/arch/powerpc/kernel/signal.c b/arch/powerpc/kernel/signal.c
> index d2c356f37077..a8bb0aca1d02 100644
> --- a/arch/powerpc/kernel/signal.c
> +++ b/arch/powerpc/kernel/signal.c
> @@ -318,7 +318,7 @@ void do_notify_resume(struct pt_regs *regs, unsigned long thread_info_flags)
>  	if (thread_info_flags & _TIF_PATCH_PENDING)
>  		klp_update_patch_state(current);
>  
> -	if (thread_info_flags & _TIF_SIGPENDING) {
> +	if (thread_info_flags & (_TIF_SIGPENDING | _TIF_NOTIFY_SIGNAL)) {
>  		BUG_ON(regs != current->thread.regs);
>  		do_signal(current);
>  	}
> -- 
> 2.29.0
>
> -- 
> Jens Axboe