On Mon, Jun 25, 2018 at 06:54:43PM +0100, Will Deacon wrote: > /* > * Please add new compat syscalls above this comment and update > diff --git a/arch/arm64/kernel/entry.S b/arch/arm64/kernel/entry.S > index 28ad8799406f..1eda9e1a1f4a 100644 > --- a/arch/arm64/kernel/entry.S > +++ b/arch/arm64/kernel/entry.S > @@ -904,6 +904,7 @@ ENDPROC(el0_error) > ret_fast_syscall: > disable_daif > str x0, [sp, #S_X0] // returned x0 > +#ifndef CONFIG_DEBUG_RSEQ > ldr x1, [tsk, #TSK_TI_FLAGS] // re-check for syscall tracing > and x2, x1, #_TIF_SYSCALL_WORK > cbnz x2, ret_fast_syscall_trace > @@ -911,6 +912,7 @@ ret_fast_syscall: > cbnz x2, work_pending > enable_step_tsk x1, x2 > kernel_exit 0 > +#endif > ret_fast_syscall_trace: > enable_daif > b __sys_trace_return_skipped // we already saved x0
I *think* this is ok, since we re-check the TIF bits in syscall_trace_exit(). This does mean that we'd now always call audit_syscall_exit(), regardless of TIF_AUDIT, but there are already cases when we call that with TIF_AUDIT clear, so I think if that's a problem it's a latent bug. Likewise for audit_syscall_entry(). It seems we're in the same boat as other architectures there, regardless. FWIW, for the entry bits: Acked-by: Mark Rutland <mark.rutl...@arm.com> Mark.
