From mboxrd@z Thu Jan 1 00:00:00 1970 From: Mathieu Desnoyers Subject: [RFC PATCH for 4.16 05/21] x86: Add support for restartable sequences Date: Thu, 14 Dec 2017 11:13:47 -0500 Message-ID: <20171214161403.30643-6-mathieu.desnoyers@efficios.com> References: <20171214161403.30643-1-mathieu.desnoyers@efficios.com> Return-path: In-Reply-To: <20171214161403.30643-1-mathieu.desnoyers@efficios.com> Sender: linux-kernel-owner@vger.kernel.org To: Peter Zijlstra , "Paul E . McKenney" , Boqun Feng , Andy Lutomirski , Dave Watson Cc: linux-kernel@vger.kernel.org, linux-api@vger.kernel.org, Paul Turner , Andrew Morton , Russell King , Thomas Gleixner , Ingo Molnar , "H . Peter Anvin" , Andrew Hunter , Andi Kleen , Chris Lameter , Ben Maurer , Steven Rostedt , Josh Triplett , Linus Torvalds , Catalin Marinas , Will Deacon , Michael Kerrisk , Mathieu Desnoyers List-Id: linux-api@vger.kernel.org Call the rseq_handle_notify_resume() function on return to userspace if TIF_NOTIFY_RESUME thread flag is set. Increment the event counter and perform fixup on the pre-signal frame when a signal is delivered on top of a restartable sequence critical section. Signed-off-by: Mathieu Desnoyers Reviewed-by: Thomas Gleixner CC: Russell King CC: Catalin Marinas CC: Will Deacon CC: Paul Turner CC: Andrew Hunter CC: Peter Zijlstra CC: Andy Lutomirski CC: Andi Kleen CC: Dave Watson CC: Chris Lameter CC: Ingo Molnar CC: "H. Peter Anvin" CC: Ben Maurer CC: Steven Rostedt CC: "Paul E. McKenney" CC: Josh Triplett CC: Linus Torvalds CC: Andrew Morton CC: Boqun Feng CC: linux-api@vger.kernel.org --- arch/x86/Kconfig | 1 + arch/x86/entry/common.c | 1 + arch/x86/kernel/signal.c | 6 ++++++ 3 files changed, 8 insertions(+) diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index 8eed3f94bfc7..aa86dab90a95 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -174,6 +174,7 @@ config X86 select HAVE_REGS_AND_STACK_ACCESS_API select HAVE_RELIABLE_STACKTRACE if X86_64 && UNWINDER_FRAME_POINTER && STACK_VALIDATION select HAVE_STACK_VALIDATION if X86_64 + select HAVE_RSEQ select HAVE_SYSCALL_TRACEPOINTS select HAVE_UNSTABLE_SCHED_CLOCK select HAVE_USER_RETURN_NOTIFIER diff --git a/arch/x86/entry/common.c b/arch/x86/entry/common.c index d7d3cc24baf4..d65595b201f4 100644 --- a/arch/x86/entry/common.c +++ b/arch/x86/entry/common.c @@ -160,6 +160,7 @@ static void exit_to_usermode_loop(struct pt_regs *regs, u32 cached_flags) if (cached_flags & _TIF_NOTIFY_RESUME) { clear_thread_flag(TIF_NOTIFY_RESUME); tracehook_notify_resume(regs); + rseq_handle_notify_resume(regs); } if (cached_flags & _TIF_USER_RETURN_NOTIFY) diff --git a/arch/x86/kernel/signal.c b/arch/x86/kernel/signal.c index b9e00e8f1c9b..991017d26d00 100644 --- a/arch/x86/kernel/signal.c +++ b/arch/x86/kernel/signal.c @@ -687,6 +687,12 @@ setup_rt_frame(struct ksignal *ksig, struct pt_regs *regs) sigset_t *set = sigmask_to_save(); compat_sigset_t *cset = (compat_sigset_t *) set; + /* + * Increment event counter and perform fixup for the pre-signal + * frame. + */ + rseq_signal_deliver(regs); + /* Set up the stack frame */ if (is_ia32_frame(ksig)) { if (ksig->ka.sa.sa_flags & SA_SIGINFO) -- 2.11.0