[PATCH] powerpc: Fix various issues with return to userspace

[Benjamin Herrenschmidt]

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 <b...@kernel.crashing.org>
---

diff --git a/arch/powerpc/kernel/entry_32.S b/arch/powerpc/kernel/entry_32.S
index 4f80cf1..3e57a00 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 d834425..6597464 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 2300426..ac6e437 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 6c0ddfc..da7d838 100644
--- a/arch/powerpc/kernel/signal.h
+++ b/arch/powerpc/kernel/signal.h
@@ -12,8 +12,6 @@
 
 #define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP)))
 
-extern void do_signal(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);
 extern void restore_sigmask(sigset_t *set);


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