On Mon, Mar 18, 2019 at 10:49:23AM +0000, Sudeep Holla wrote:
> Now that we have a new hook ptrace_syscall_enter that can be called from
> syscall entry code and it handles PTRACE_SYSEMU in generic code, we
> can do some cleanup using the same in do_syscall_trace_enter.
>
> Cc: Oleg Nesterov <o...@redhat.com>
> Cc: Paul Mackerras <pau...@samba.org>
> Cc: Michael Ellerman <m...@ellerman.id.au>
> Signed-off-by: Sudeep Holla <sudeep.ho...@arm.com>
> ---
> arch/powerpc/kernel/ptrace.c | 48 ++++++++++++++++--------------------
> 1 file changed, 21 insertions(+), 27 deletions(-)
>
> diff --git a/arch/powerpc/kernel/ptrace.c b/arch/powerpc/kernel/ptrace.c
> index 2e2183b800a8..05579a5dcb12 100644
> --- a/arch/powerpc/kernel/ptrace.c
> +++ b/arch/powerpc/kernel/ptrace.c
> @@ -3278,35 +3278,29 @@ long do_syscall_trace_enter(struct pt_regs *regs)
>
> user_exit();
>
> - flags = READ_ONCE(current_thread_info()->flags) &
> - (_TIF_SYSCALL_EMU | _TIF_SYSCALL_TRACE);
> -
> - if (flags) {
> - int rc = tracehook_report_syscall_entry(regs);
> + if (unlikely(ptrace_syscall_enter(regs))) {
> + /*
> + * A nonzero return code from tracehook_report_syscall_entry()
> + * tells us to prevent the syscall execution, but we are not
> + * going to execute it anyway.
> + *
> + * Returning -1 will skip the syscall execution. We want to
> + * avoid clobbering any registers, so we don't goto the skip
> + * label below.
> + */
> + return -1;
> + }This comment is out of sync with the changed code. -- ldv
signature.asc
Description: PGP signature
