From ca46ebffc2d2b243cc213d444e2a440489ecd4bc Mon Sep 17 00:00:00 2001 From: Stafford Horne Date: Thu, 12 Dec 2024 12:33:56 +0000 Subject: [PATCH] openrisc: Add support for restartable sequences Implement support for restartable sequences on OpenRISC by doing: - Select HAVE_RSEQ in Kconfig - Call rseq_syscall() on return to userspace when CONFIG_DEBUG_RSEQ is enabled. - Call rseq_signal_deliver() to fixup the pre-signal stack frame when a signal is delivered on top of a restartable sequence critical section Cc: Michael Jeanson Signed-off-by: Stafford Horne --- arch/openrisc/Kconfig | 1 + arch/openrisc/kernel/entry.S | 4 ++++ arch/openrisc/kernel/signal.c | 2 ++ 3 files changed, 7 insertions(+) diff --git a/arch/openrisc/Kconfig b/arch/openrisc/Kconfig index 607a59bc2a22d..b38fee299bc48 100644 --- a/arch/openrisc/Kconfig +++ b/arch/openrisc/Kconfig @@ -28,6 +28,7 @@ config OPENRISC select HAVE_UID16 select HAVE_PAGE_SIZE_8KB select HAVE_REGS_AND_STACK_ACCESS_API + select HAVE_RSEQ select GENERIC_ATOMIC64 select GENERIC_CLOCKEVENTS_BROADCAST select GENERIC_SMP_IDLE_THREAD diff --git a/arch/openrisc/kernel/entry.S b/arch/openrisc/kernel/entry.S index ce6f2b08a35ed..c7e90b09645e4 100644 --- a/arch/openrisc/kernel/entry.S +++ b/arch/openrisc/kernel/entry.S @@ -714,6 +714,10 @@ _syscall_check_trace_leave: * interrupts that set NEED_RESCHED or SIGNALPENDING... really true? */ _syscall_check_work: +#ifdef CONFIG_DEBUG_RSEQ + l.jal rseq_syscall + l.ori r3,r1,0 +#endif /* Here we need to disable interrupts */ DISABLE_INTERRUPTS(r27,r29) TRACE_IRQS_OFF diff --git a/arch/openrisc/kernel/signal.c b/arch/openrisc/kernel/signal.c index c7ab42e2cb7a4..f70a13ee05936 100644 --- a/arch/openrisc/kernel/signal.c +++ b/arch/openrisc/kernel/signal.c @@ -244,6 +244,8 @@ handle_signal(struct ksignal *ksig, struct pt_regs *regs) { int ret; + rseq_signal_deliver(ksig, regs); + ret = setup_rt_frame(ksig, sigmask_to_save(), regs); signal_setup_done(ret, ksig, test_thread_flag(TIF_SINGLESTEP));