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authorPaul Burton <paul.burton@mips.com>2018-06-14 10:13:53 -0700
committerPaul Burton <paul.burton@mips.com>2018-06-19 21:13:17 -0700
commit9ea141ad54716d48e79d0093052c12ed67debf09 (patch)
treed6b3b439562aaf1d21303078623f7e05793a9b02
parent18f3e95b90b28318ef35910d21c39908de672331 (diff)
downloadtalos-obmc-linux-9ea141ad54716d48e79d0093052c12ed67debf09.tar.gz
talos-obmc-linux-9ea141ad54716d48e79d0093052c12ed67debf09.zip
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 <paul.burton@mips.com> Reviewed-by: James Hogan <jhogan@kernel.org> Patchwork: https://patchwork.linux-mips.org/patch/19523/ Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Boqun Feng <boqun.feng@gmail.com> Cc: linux-mips@linux-mips.org Cc: linux-kernel@vger.kernel.org
-rw-r--r--arch/mips/Kconfig1
-rw-r--r--arch/mips/kernel/signal.c3
2 files changed, 4 insertions, 0 deletions
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();
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