x86 ptrace: user-sets-TF nits

This closes some arcane holes in single-step handling that can arise
only when user programs set TF directly (via popf or sigreturn) and
then use vDSO (syscall/sysenter) system call entry.  In those entry
paths, the clear_TF_reenable case hits and we must check TIF_SINGLESTEP
to be sure our bookkeeping stays correct wrt the user's view of TF.

Signed-off-by: Roland McGrath <roland@redhat.com>

1 files changed, 1 insertions, 1 deletions

diff --git a/include/asm-x86/thread_info.h b/include/asm-x86/thread_info.h
index b2702a1eeac1..0a8f27d31d0d 100644
--- a/include/asm-x86/thread_info.h
+++ b/include/asm-x86/thread_info.h
@@ -118,7 +118,7 @@ struct thread_info {
 /* work to do in syscall_trace_enter() */
 #define _TIF_WORK_SYSCALL_ENTRY \
         (_TIF_SYSCALL_TRACE | _TIF_SYSCALL_EMU | \
-         _TIF_SYSCALL_AUDIT | _TIF_SECCOMP)
+         _TIF_SYSCALL_AUDIT | _TIF_SECCOMP | _TIF_SINGLESTEP)
 
 /* work to do in syscall_trace_leave() */
 #define _TIF_WORK_SYSCALL_EXIT  \