From 9ea141ad54716d48e79d0093052c12ed67debf09 Mon Sep 17 00:00:00 2001 From: Paul Burton Date: Thu, 14 Jun 2018 10:13:53 -0700 Subject: [PATCH] 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/Kconfig | 1 + arch/mips/kernel/signal.c | 3 +++ 2 files changed, 4 insertions(+) diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig index 3f9deec70b92..08c10c518f83 100644 --- a/arch/mips/Kconfig +++ b/arch/mips/Kconfig @@ -65,6 +65,7 @@ config MIPS select HAVE_OPROFILE select HAVE_PERF_EVENTS select HAVE_REGS_AND_STACK_ACCESS_API + select HAVE_RSEQ select HAVE_STACKPROTECTOR select HAVE_SYSCALL_TRACEPOINTS select HAVE_VIRT_CPU_ACCOUNTING_GEN if 64BIT || !SMP 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(); -- 2.30.2