[RFC PATCH for 4.17 07/21] powerpc: Add support for restartable sequences
From: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Date: 2018-03-27 16:16:03
Also in:
linuxppc-dev, lkml
Subsystem:
linux for powerpc (32-bit and 64-bit), the rest · Maintainers:
Madhavan Srinivasan, Michael Ellerman, Linus Torvalds
From: Boqun Feng <redacted> 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 when a signal is delivered on top of a restartable sequence critical section. Signed-off-by: Boqun Feng <redacted> Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> CC: Benjamin Herrenschmidt <benh@kernel.crashing.org> CC: Paul Mackerras <redacted> CC: Michael Ellerman <mpe@ellerman.id.au> CC: Peter Zijlstra <peterz@infradead.org> CC: "Paul E. McKenney" <redacted> CC: linuxppc-dev@lists.ozlabs.org --- arch/powerpc/Kconfig | 1 + arch/powerpc/kernel/signal.c | 3 +++ 2 files changed, 4 insertions(+)
diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index 73ce5dd07642..90700b6918ef 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig@@ -223,6 +223,7 @@ config PPC select HAVE_SYSCALL_TRACEPOINTS select HAVE_VIRT_CPU_ACCOUNTING select HAVE_IRQ_TIME_ACCOUNTING + select HAVE_RSEQ select IRQ_DOMAIN select IRQ_FORCED_THREADING select MODULES_USE_ELF_RELA
diff --git a/arch/powerpc/kernel/signal.c b/arch/powerpc/kernel/signal.c
index 61db86ecd318..d3bb3aaaf5ac 100644
--- a/arch/powerpc/kernel/signal.c
+++ b/arch/powerpc/kernel/signal.c@@ -133,6 +133,8 @@ static void do_signal(struct task_struct *tsk) /* Re-enable the breakpoints for the signal stack */ thread_change_pc(tsk, tsk->thread.regs); + rseq_signal_deliver(tsk->thread.regs); + if (is32) { if (ksig.ka.sa.sa_flags & SA_SIGINFO) ret = handle_rt_signal32(&ksig, oldset, tsk);
@@ -164,6 +166,7 @@ void do_notify_resume(struct pt_regs *regs, unsigned long thread_info_flags) if (thread_info_flags & _TIF_NOTIFY_RESUME) { clear_thread_flag(TIF_NOTIFY_RESUME); tracehook_notify_resume(regs); + rseq_handle_notify_resume(regs); } user_enter();
--
2.11.0