From 5a157d5bf8288eaa86ec269a966559594ddd542e Mon Sep 17 00:00:00 2001
From: "David S. Miller" <davem@davemloft.net>
Date: Sun, 27 Jul 2008 03:38:53 -0700
Subject: [PATCH] sparc: Create and use TIF_NOTIFY_RESUME.

Signed-off-by: David S. Miller <davem@davemloft.net>
---
 arch/sparc/include/asm/thread_info_32.h |  7 ++++++-
 arch/sparc/kernel/rtrap.S               |  5 +++--
 arch/sparc/kernel/signal.c              | 14 +++++++++++++-
 3 files changed, 22 insertions(+), 4 deletions(-)

diff --git a/arch/sparc/include/asm/thread_info_32.h b/arch/sparc/include/asm/thread_info_32.h
index 2cf9db0440..cbb892d0df 100644
--- a/arch/sparc/include/asm/thread_info_32.h
+++ b/arch/sparc/include/asm/thread_info_32.h
@@ -130,7 +130,7 @@ BTFIXUPDEF_CALL(void, free_thread_info, struct thread_info *)
  * thread information flag bit numbers
  */
 #define TIF_SYSCALL_TRACE	0	/* syscall trace active */
-/* flag bit 1 is available */
+#define TIF_NOTIFY_RESUME	1	/* callback before returning to user */
 #define TIF_SIGPENDING		2	/* signal pending */
 #define TIF_NEED_RESCHED	3	/* rescheduling necessary */
 #define TIF_RESTORE_SIGMASK	4	/* restore signal mask in do_signal() */
@@ -142,12 +142,17 @@ BTFIXUPDEF_CALL(void, free_thread_info, struct thread_info *)
 
 /* as above, but as bit values */
 #define _TIF_SYSCALL_TRACE	(1<<TIF_SYSCALL_TRACE)
+#define _TIF_NOTIFY_RESUME	(1<<TIF_NOTIFY_RESUME)
 #define _TIF_SIGPENDING		(1<<TIF_SIGPENDING)
 #define _TIF_NEED_RESCHED	(1<<TIF_NEED_RESCHED)
 #define _TIF_RESTORE_SIGMASK	(1<<TIF_RESTORE_SIGMASK)
 #define _TIF_USEDFPU		(1<<TIF_USEDFPU)
 #define _TIF_POLLING_NRFLAG	(1<<TIF_POLLING_NRFLAG)
 
+#define _TIF_DO_NOTIFY_RESUME_MASK	(_TIF_NOTIFY_RESUME | \
+					 _TIF_SIGPENDING | \
+					 _TIF_RESTORE_SIGMASK)
+
 #endif /* __KERNEL__ */
 
 #endif /* _ASM_THREAD_INFO_H */
diff --git a/arch/sparc/kernel/rtrap.S b/arch/sparc/kernel/rtrap.S
index 891f460b7b..4da2e1f662 100644
--- a/arch/sparc/kernel/rtrap.S
+++ b/arch/sparc/kernel/rtrap.S
@@ -69,12 +69,13 @@ ret_trap_lockless_ipi:
 
 	ld	[%curptr + TI_FLAGS], %g2
 signal_p:
-	andcc	%g2, (_TIF_SIGPENDING|_TIF_RESTORE_SIGMASK), %g0
+	andcc	%g2, _TIF_DO_NOTIFY_RESUME_MASK, %g0
 	bz,a	ret_trap_continue
 	 ld	[%sp + STACKFRAME_SZ + PT_PSR], %t_psr
 
+	mov	%g2, %o2
 	mov	%l5, %o1
-	call	do_signal
+	call	do_notify_resume
 	 add	%sp, STACKFRAME_SZ, %o0	! pt_regs ptr
 
 	/* Fall through. */
diff --git a/arch/sparc/kernel/signal.c b/arch/sparc/kernel/signal.c
index 3fd1df9f9b..bee6ba34e0 100644
--- a/arch/sparc/kernel/signal.c
+++ b/arch/sparc/kernel/signal.c
@@ -18,6 +18,7 @@
 #include <linux/smp.h>
 #include <linux/binfmts.h>	/* do_coredum */
 #include <linux/bitops.h>
+#include <linux/tracehook.h>
 
 #include <asm/uaccess.h>
 #include <asm/ptrace.h>
@@ -513,7 +514,7 @@ static inline void syscall_restart(unsigned long orig_i0, struct pt_regs *regs,
  * want to handle. Thus you cannot kill init even with a SIGKILL even by
  * mistake.
  */
-asmlinkage void do_signal(struct pt_regs * regs, unsigned long orig_i0)
+static void do_signal(struct pt_regs *regs, unsigned long orig_i0)
 {
 	struct k_sigaction ka;
 	int restart_syscall;
@@ -579,6 +580,17 @@ asmlinkage void do_signal(struct pt_regs * regs, unsigned long orig_i0)
 	}
 }
 
+void do_notify_resume(struct pt_regs *regs, unsigned long orig_i0,
+		      unsigned long thread_info_flags)
+{
+	if (thread_info_flags & (_TIF_SIGPENDING | _TIF_RESTORE_SIGMASK))
+		do_signal(regs, orig_i0);
+	if (thread_info_flags & _TIF_NOTIFY_RESUME) {
+		clear_thread_flag(TIF_NOTIFY_RESUME);
+		tracehook_notify_resume(regs);
+	}
+}
+
 asmlinkage int
 do_sys_sigstack(struct sigstack __user *ssptr, struct sigstack __user *ossptr,
 		unsigned long sp)
-- 
2.39.5