[PATCH 05/17] arm: TIF_NOTIFY_RESUME

From: Roland McGrath
Date: Fri Apr 24 2009 - 20:11:34 EST


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@xxxxxxxxxx>
---
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);
+ }
}
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