powerpc: Add TIF_NOTIFY_RESUME support for tracehook

This adds TIF_NOTIFY_RESUME support for powerpc.  When set,
we call tracehook_notify_resume() on the way to user mode.
This overloads do_signal() to do the work, but changes its
arguments to it has the TIF_* bits handy in a register and
drops the useless first argument that was always zero.

Signed-off-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

1 files changed, 4 insertions, 1 deletions

diff --git a/include/asm-powerpc/thread_info.h b/include/asm-powerpc/thread_info.h
index a9db562df69a..9665a26a253a 100644
--- a/include/asm-powerpc/thread_info.h
+++ b/include/asm-powerpc/thread_info.h
@@ -108,6 +108,7 @@ static inline struct thread_info *current_thread_info(void)
 #define TIF_SECCOMP             10      /* secure computing */
 #define TIF_RESTOREALL          11      /* Restore all regs (implies NOERROR) */
 #define TIF_NOERROR             12      /* Force successful syscall return */
+#define TIF_NOTIFY_RESUME       13      /* callback before returning to user */
 #define TIF_FREEZE              14      /* Freezing for suspend */
 #define TIF_RUNLATCH            15      /* Is the runlatch enabled? */
 #define TIF_ABI_PENDING         16      /* 32/64 bit switch needed */
@@ -125,12 +126,14 @@ static inline struct thread_info *current_thread_info(void)
 #define _TIF_SECCOMP            (1<<TIF_SECCOMP)
 #define _TIF_RESTOREALL         (1<<TIF_RESTOREALL)
 #define _TIF_NOERROR            (1<<TIF_NOERROR)
+#define _TIF_NOTIFY_RESUME      (1<<TIF_NOTIFY_RESUME)
 #define _TIF_FREEZE             (1<<TIF_FREEZE)
 #define _TIF_RUNLATCH           (1<<TIF_RUNLATCH)
 #define _TIF_ABI_PENDING        (1<<TIF_ABI_PENDING)
 #define _TIF_SYSCALL_T_OR_A     (_TIF_SYSCALL_TRACE|_TIF_SYSCALL_AUDIT|_TIF_SECCOMP)
 
-#define _TIF_USER_WORK_MASK     (_TIF_SIGPENDING | _TIF_NEED_RESCHED)
+#define _TIF_USER_WORK_MASK     (_TIF_SIGPENDING | _TIF_NEED_RESCHED | \
+                                 _TIF_NOTIFY_RESUME)
 #define _TIF_PERSYSCALL_MASK    (_TIF_RESTOREALL|_TIF_NOERROR)
 
 /* Bits in local_flags */