[PATCH 05/17] arm: TIF_NOTIFY_RESUME

[Roland McGrath <roland@redhat.com>]

This makes arm support TIF_NOTIFY_RESUME, so that set_notify_resume()
requests a call to tracehook_notify_resume() on the way back to user mode.

Signed-off-by: Roland McGrath <roland@redhat.com>
---
 arch/arm/include/asm/thread_info.h |    4 ++++
 arch/arm/kernel/entry-common.S     |    2 +-
 arch/arm/kernel/signal.c           |    5 +++++
 3 files changed, 10 insertions(+), 1 deletions(-)

diff --git a/arch/arm/include/asm/thread_info.h b/arch/arm/include/asm/thread_info.h
index 4f88482..def86a0 100644
--- a/arch/arm/include/asm/thread_info.h
+++ b/arch/arm/include/asm/thread_info.h
@@ -129,12 +129,14 @@ extern void vfp_sync_state(struct thread_info *thread);
  * thread information flags:
  *  TIF_SYSCALL_TRACE	- syscall trace active
  *  TIF_SIGPENDING	- signal pending
+ *  TIF_NOTIFY_RESUME	- tracing notification pending
  *  TIF_NEED_RESCHED	- rescheduling necessary
  *  TIF_USEDFPU		- FPU was used by this task this quantum (SMP)
  *  TIF_POLLING_NRFLAG	- true if poll_idle() is polling TIF_NEED_RESCHED
  */
 #define TIF_SIGPENDING		0
 #define TIF_NEED_RESCHED	1
+#define TIF_NOTIFY_RESUME	2
 #define TIF_SYSCALL_TRACE	8
 #define TIF_POLLING_NRFLAG	16
 #define TIF_USING_IWMMXT	17
@@ -142,6 +144,7 @@ extern void vfp_sync_state(struct thread_info *thread);
 #define TIF_FREEZE		19
 
 #define _TIF_SIGPENDING		(1 << TIF_SIGPENDING)
+#define _TIF_NOTIFY_RESUME	(1 << TIF_NOTIFY_RESUME)
 #define _TIF_NEED_RESCHED	(1 << TIF_NEED_RESCHED)
 #define _TIF_SYSCALL_TRACE	(1 << TIF_SYSCALL_TRACE)
 #define _TIF_POLLING_NRFLAG	(1 << TIF_POLLING_NRFLAG)
@@ -152,6 +155,7 @@ extern void vfp_sync_state(struct thread_info *thread);
  * Change these and you break ASM code in entry-common.S
  */
 #define _TIF_WORK_MASK		0x000000ff
+#define _TIF_DO_NOTIFY_RESUME	(_TIF_SIGPENDING | _TIF_NOTIFY_RESUME)
 
 #endif /* __KERNEL__ */
 #endif /* __ASM_ARM_THREAD_INFO_H */
diff --git a/arch/arm/kernel/entry-common.S b/arch/arm/kernel/entry-common.S
index b55cb03..2523cac 100644
--- a/arch/arm/kernel/entry-common.S
+++ b/arch/arm/kernel/entry-common.S
@@ -51,7 +51,7 @@ fast_work_pending:
 work_pending:
 	tst	r1, #_TIF_NEED_RESCHED
 	bne	work_resched
-	tst	r1, #_TIF_SIGPENDING
+	tst	r1, #_TIF_DO_NOTIFY_RESUME
 	beq	no_work_pending
 	mov	r0, sp				@ 'regs'
 	mov	r2, why				@ 'syscall'
diff --git a/arch/arm/kernel/signal.c b/arch/arm/kernel/signal.c
index 51e2187..6663ee0 100644
--- a/arch/arm/kernel/signal.c
+++ b/arch/arm/kernel/signal.c
@@ -705,4 +705,9 @@ do_notify_resume(struct pt_regs *regs, unsigned int thread_flags, int syscall)
 {
 	if (thread_flags & _TIF_SIGPENDING)
 		do_signal(&current->blocked, regs, syscall);
+
+	if (thread_flags & _TIF_NOTIFY_RESUME) {
+		clear_thread_flag(TIF_NOTIFY_RESUME);
+		tracehook_notify_resume(regs);
+	}
 }