powerpc: Fix various issues with return to userspace

We have a few problems when returning to userspace. This is a
quick set of fixes for 3.3, I'll look into a more comprehensive
rework for 3.4. This fixes:

 - We kept interrupts soft-disabled when schedule'ing or calling
do_signal when returning to userspace as a result of a hardware
interrupt.

 - Rename do_signal to do_notify_resume like all other archs (and
do_signal_pending back to do_signal, which it was before Roland
changed it).

 - Add the missing call to key_replace_session_keyring() to
do_notify_resume().

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
---

4 files changed, 15 insertions, 7 deletions

diff --git a/arch/powerpc/kernel/entry_32.S b/arch/powerpc/kernel/entry_32.S
index 4f80cf1ce77b..3e57a00b8cba 100644
--- a/arch/powerpc/kernel/entry_32.S
+++ b/arch/powerpc/kernel/entry_32.S
@@ -1213,7 +1213,7 @@ do_user_signal:			/* r10 contains MSR_KERNEL here */
         stw     r3,_TRAP(r1)
 2:      addi    r3,r1,STACK_FRAME_OVERHEAD
         mr      r4,r9
-        bl      do_signal
+        bl      do_notify_resume
         REST_NVGPRS(r1)
         b       recheck
 
diff --git a/arch/powerpc/kernel/entry_64.S b/arch/powerpc/kernel/entry_64.S
index d834425186ae..866462cbe2d8 100644
--- a/arch/powerpc/kernel/entry_64.S
+++ b/arch/powerpc/kernel/entry_64.S
@@ -751,12 +751,16 @@ user_work:
 
         andi.   r0,r4,_TIF_NEED_RESCHED
         beq     1f
+        li      r5,1
+        TRACE_AND_RESTORE_IRQ(r5);
         bl      .schedule
         b       .ret_from_except_lite
 
 1:      bl      .save_nvgprs
+        li      r5,1
+        TRACE_AND_RESTORE_IRQ(r5);
         addi    r3,r1,STACK_FRAME_OVERHEAD
-        bl      .do_signal
+        bl      .do_notify_resume
         b       .ret_from_except
 
 unrecov_restore:
diff --git a/arch/powerpc/kernel/signal.c b/arch/powerpc/kernel/signal.c
index 2300426e531a..ac6e437b1021 100644
--- a/arch/powerpc/kernel/signal.c
+++ b/arch/powerpc/kernel/signal.c
@@ -11,6 +11,7 @@
 
 #include <linux/tracehook.h>
 #include <linux/signal.h>
+#include <linux/key.h>
 #include <asm/hw_breakpoint.h>
 #include <asm/uaccess.h>
 #include <asm/unistd.h>
@@ -113,8 +114,9 @@ static void check_syscall_restart(struct pt_regs *regs, struct k_sigaction *ka,
         }
 }
 
-static int do_signal_pending(sigset_t *oldset, struct pt_regs *regs)
+static int do_signal(struct pt_regs *regs)
 {
+        sigset_t *oldset;
         siginfo_t info;
         int signr;
         struct k_sigaction ka;
@@ -123,7 +125,7 @@ static int do_signal_pending(sigset_t *oldset, struct pt_regs *regs)
 
         if (current_thread_info()->local_flags & _TLF_RESTORE_SIGMASK)
                 oldset = &current->saved_sigmask;
-        else if (!oldset)
+        else
                 oldset = &current->blocked;
 
         signr = get_signal_to_deliver(&info, &ka, regs, NULL);
@@ -191,14 +193,16 @@ static int do_signal_pending(sigset_t *oldset, struct pt_regs *regs)
         return ret;
 }
 
-void do_signal(struct pt_regs *regs, unsigned long thread_info_flags)
+void do_notify_resume(struct pt_regs *regs, unsigned long thread_info_flags)
 {
         if (thread_info_flags & _TIF_SIGPENDING)
-                do_signal_pending(NULL, regs);
+                do_signal(regs);
 
         if (thread_info_flags & _TIF_NOTIFY_RESUME) {
                 clear_thread_flag(TIF_NOTIFY_RESUME);
                 tracehook_notify_resume(regs);
+                if (current->replacement_session_keyring)
+                        key_replace_session_keyring();
         }
 }
 
diff --git a/arch/powerpc/kernel/signal.h b/arch/powerpc/kernel/signal.h
index 6c0ddfc0603e..8dde973aaaf5 100644
--- a/arch/powerpc/kernel/signal.h
+++ b/arch/powerpc/kernel/signal.h
@@ -12,7 +12,7 @@
 
 #define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP)))
 
-extern void do_signal(struct pt_regs *regs, unsigned long thread_info_flags);
+extern void do_notify_resume(struct pt_regs *regs, unsigned long thread_info_flags);
 
 extern void __user * get_sigframe(struct k_sigaction *ka, struct pt_regs *regs,
                                   size_t frame_size, int is_32);