Re: [PATCH] MIPS: Add ksig argument to rseq_{signal_deliver,handle_notify_resume}

From: Mathieu Desnoyers
Date: Sun Jun 24 2018 - 13:08:37 EST


----- On Jun 24, 2018, at 12:58 PM, Paul Burton paul.burton@xxxxxxxx wrote:

> Commit 784e0300fe9f ("rseq: Avoid infinite recursion when delivering
> SIGSEGV") added a new ksig argument to the rseq_signal_deliver() &
> rseq_handle_notify_resume() functions, and was merged in v4.18-rc2.
> Meanwhile MIPS support for restartable sequences was also merged in
> v4.18-rc2 with commit 9ea141ad5471 ("MIPS: Add support for restartable
> sequences"), and therefore didn't get updated for the API change.
>
> This results in build failures like the following:
>
> CC arch/mips/kernel/signal.o
> arch/mips/kernel/signal.c: In function 'handle_signal':
> arch/mips/kernel/signal.c:804:22: error: passing argument 1 of
> 'rseq_signal_deliver' from incompatible pointer type
> [-Werror=incompatible-pointer-types]
> rseq_signal_deliver(regs);
> ^~~~
> In file included from ./include/linux/context_tracking.h:5,
> from arch/mips/kernel/signal.c:12:
> ./include/linux/sched.h:1811:56: note: expected 'struct ksignal *' but
> argument is of type 'struct pt_regs *'
> static inline void rseq_signal_deliver(struct ksignal *ksig,
> ~~~~~~~~~~~~~~~~^~~~
> arch/mips/kernel/signal.c:804:2: error: too few arguments to function
> 'rseq_signal_deliver'
> rseq_signal_deliver(regs);
> ^~~~~~~~~~~~~~~~~~~
>
> Fix this by adding the ksig argument as was done for other architectures
> in commit 784e0300fe9f ("rseq: Avoid infinite recursion when delivering
> SIGSEGV").

Looks like we both noticed the same issue. Your commit message is more
exhaustive than mine, so yours should be merged rather than mine.

Acked-by: Mathieu Desnoyers <mathieu.desnoyers@xxxxxxxxxxxx>

Thanks!

Mathieu

>
> Signed-off-by: Paul Burton <paul.burton@xxxxxxxx>
> Cc: James Hogan <jhogan@xxxxxxxxxx>
> Cc: Ralf Baechle <ralf@xxxxxxxxxxxxxx>
> Cc: Mathieu Desnoyers <mathieu.desnoyers@xxxxxxxxxxxx>
> Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
> Cc: Paul E. McKenney <paulmck@xxxxxxxxxxxxxxxxxx>
> Cc: Boqun Feng <boqun.feng@xxxxxxxxx>
> Cc: Will Deacon <will.deacon@xxxxxxx>
> Cc: linux-mips@xxxxxxxxxxxxxx
> Cc: linux-kernel@xxxxxxxxxxxxxxx
> ---
>
> arch/mips/kernel/signal.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/arch/mips/kernel/signal.c b/arch/mips/kernel/signal.c
> index 00f2535d2226..0a9cfe7a0372 100644
> --- a/arch/mips/kernel/signal.c
> +++ b/arch/mips/kernel/signal.c
> @@ -801,7 +801,7 @@ static void handle_signal(struct ksignal *ksig, struct
> pt_regs *regs)
> regs->regs[0] = 0; /* Don't deal with this again. */
> }
>
> - rseq_signal_deliver(regs);
> + rseq_signal_deliver(ksig, regs);
>
> if (sig_uses_siginfo(&ksig->ka, abi))
> ret = abi->setup_rt_frame(vdso + abi->vdso->off_rt_sigreturn,
> @@ -870,7 +870,7 @@ asmlinkage void do_notify_resume(struct pt_regs *regs, void
> *unused,
> if (thread_info_flags & _TIF_NOTIFY_RESUME) {
> clear_thread_flag(TIF_NOTIFY_RESUME);
> tracehook_notify_resume(regs);
> - rseq_handle_notify_resume(regs);
> + rseq_handle_notify_resume(NULL, regs);
> }
>
> user_enter();
> --
> 2.17.1

--
Mathieu Desnoyers
EfficiOS Inc.
http://www.efficios.com