From 9ea141ad54716d48e79d0093052c12ed67debf09 Mon Sep 17 00:00:00 2001 From: Paul Burton Date: Thu, 14 Jun 2018 10:13:53 -0700 Subject: MIPS: Add support for restartable sequences Implement support for restartable sequences on MIPS, which requires 3 simple things: - Call rseq_handle_notify_resume() on return to userspace if TIF_NOTIFY_RESUME is set. - Call rseq_signal_deliver() to fixup the pre-signal stack frame when a signal is delivered whilst executing a restartable sequence critical section. - Select CONFIG_HAVE_RSEQ. Signed-off-by: Paul Burton Reviewed-by: James Hogan Patchwork: https://patchwork.linux-mips.org/patch/19523/ Cc: Ralf Baechle Cc: Mathieu Desnoyers Cc: Peter Zijlstra Cc: Paul E. McKenney Cc: Boqun Feng Cc: linux-mips@linux-mips.org Cc: linux-kernel@vger.kernel.org --- arch/mips/kernel/signal.c | 3 +++ 1 file changed, 3 insertions(+) (limited to 'arch/mips/kernel/signal.c') diff --git a/arch/mips/kernel/signal.c b/arch/mips/kernel/signal.c index 9e224469c788..00f2535d2226 100644 --- a/arch/mips/kernel/signal.c +++ b/arch/mips/kernel/signal.c @@ -801,6 +801,8 @@ 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); + if (sig_uses_siginfo(&ksig->ka, abi)) ret = abi->setup_rt_frame(vdso + abi->vdso->off_rt_sigreturn, ksig, regs, oldset); @@ -868,6 +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); } user_enter(); -- cgit From 662d855c66c0a7400f9117b6ac02047942cd1d22 Mon Sep 17 00:00:00 2001 From: Paul Burton Date: Sun, 24 Jun 2018 09:33:22 -0700 Subject: MIPS: Add ksig argument to rseq_{signal_deliver,handle_notify_resume} 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"). Signed-off-by: Paul Burton Acked-by: Mathieu Desnoyers Patchwork: https://patchwork.linux-mips.org/patch/19603/ Cc: James Hogan Cc: Ralf Baechle Cc: Peter Zijlstra Cc: Paul E. McKenney Cc: Boqun Feng Cc: Will Deacon Cc: linux-mips@linux-mips.org Cc: linux-kernel@vger.kernel.org --- arch/mips/kernel/signal.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'arch/mips/kernel/signal.c') 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(); -- cgit