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.burton@xxxxxxxx> Cc: James Hogan <jhogan@xxxxxxxxxx> Cc: Ralf Baechle <ralf@xxxxxxxxxxxxxx> Cc: Mathieu Desnoyers <mathieu.desnoyers@xxxxxxxxxxxx> Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx> Cc: Paul E. McKenney <paulmck@xxxxxxxxxxxxxxxxxx> Cc: Boqun Feng <boqun.feng@xxxxxxxxx> Cc: linux-mips@xxxxxxxxxxxxxx Cc: linux-kernel@xxxxxxxxxxxxxxx --- 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
