Syscalls are not allowed inside restartable sequences, so add a call to
rseq_syscall() at the very beginning of the system call exit path when
CONFIG_DEBUG_RSEQ=y. This will help us to detect whether there is a
syscall issued erroneously inside a restartable sequence.
Signed-off-by: Paul Burton <paul.bur...@mips.com>
Cc: James Hogan <jho...@kernel.org>
Cc: Ralf Baechle <r...@linux-mips.org>
Cc: Mathieu Desnoyers <mathieu.desnoy...@efficios.com>
Cc: Peter Zijlstra <pet...@infradead.org>
Cc: Paul E. McKenney <paul...@linux.vnet.ibm.com>
Cc: Boqun Feng <boqun.f...@gmail.com>
Cc: linux-m...@linux-mips.org
Cc: linux-kernel@vger.kernel.org
---
arch/mips/kernel/entry.S | 8 ++++++++
1 file changed, 8 insertions(+)
diff --git a/arch/mips/kernel/entry.S b/arch/mips/kernel/entry.S
index 38a302919e6b..d7de8adcfcc8 100644
--- a/arch/mips/kernel/entry.S
+++ b/arch/mips/kernel/entry.S
@@ -79,6 +79,10 @@ FEXPORT(ret_from_fork)
jal schedule_tail # a0 = struct task_struct *prev
FEXPORT(syscall_exit)
+#ifdef CONFIG_DEBUG_RSEQ
+ move a0, sp
+ jal rseq_syscall
+#endif
local_irq_disable # make sure need_resched and
# signals dont change between
# sampling and return
@@ -141,6 +145,10 @@ work_notifysig: # deal with
pending signals and
j resume_userspace_check
FEXPORT(syscall_exit_partial)
+#ifdef CONFIG_DEBUG_RSEQ
+ move a0, sp
+ jal rseq_syscall
+#endif
local_irq_disable # make sure need_resched doesn't
# change between and return
LONG_L a2, TI_FLAGS($28) # current->work
--
2.17.1
