Thread (64 messages) flat view 64 messages, 6 authors, 2016-08-11

Re: [RFC 2/4] Restartable sequences: powerpc architecture support

From: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Date: 2016-07-28 03:13:20
Also in: lkml

----- On Jul 27, 2016, at 11:05 AM, Boqun Feng boqun.feng@gmail.com wrote:
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.
Picked into my patchset. I'm keeping a volatile branch of my current
work at https://github.com/compudj/linux-percpu-dev/tree/rseq-fallback
if you are interested in the progress.

Thanks!

Mathieu
quoted hunk ↗ jump to hunk
Signed-off-by: Boqun Feng <redacted>
---
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 0a9d439bcda6..4e93629c6b84 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -120,6 +120,7 @@ config PPC
	select HAVE_PERF_USER_STACK_DUMP
	select HAVE_REGS_AND_STACK_ACCESS_API
	select HAVE_HW_BREAKPOINT if PERF_EVENTS && PPC_BOOK3S_64
+	select HAVE_RSEQ
	select ARCH_WANT_IPC_PARSE_VERSION
	select SPARSE_IRQ
	select IRQ_DOMAIN
diff --git a/arch/powerpc/kernel/signal.c b/arch/powerpc/kernel/signal.c
index cb64d6feb45a..339d0ebe2906 100644
--- a/arch/powerpc/kernel/signal.c
+++ b/arch/powerpc/kernel/signal.c
@@ -131,6 +131,8 @@ static void do_signal(struct pt_regs *regs)
	/* Re-enable the breakpoints for the signal stack */
	thread_change_pc(current, regs);

+	rseq_signal_deliver(regs);
+
	if (is32) {
        	if (ksig.ka.sa.sa_flags & SA_SIGINFO)
			ret = handle_rt_signal32(&ksig, oldset, regs);
@@ -157,6 +159,7 @@ 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();
--
2.9.0
-- 
Mathieu Desnoyers
EfficiOS Inc.
http://www.efficios.com
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