[PATCH] TIF_RESTORE_SIGMASK support for arch/powerpc

Implement the TIF_RESTORE_SIGMASK flag in the new arch/powerpc kernel, for
both 32-bit and 64-bit system call paths.

Signed-off-by: David Woodhouse <dwmw2@infradead.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

5 files changed, 40 insertions, 12 deletions

diff --git a/arch/powerpc/kernel/entry_32.S b/arch/powerpc/kernel/entry_32.S
index d8da2a35c0a4..f20a67261ec7 100644
--- a/arch/powerpc/kernel/entry_32.S
+++ b/arch/powerpc/kernel/entry_32.S
@@ -227,7 +227,7 @@ ret_from_syscall:
         MTMSRD(r10)
         lwz     r9,TI_FLAGS(r12)
         li      r8,-_LAST_ERRNO
-        andi.   r0,r9,(_TIF_SYSCALL_T_OR_A|_TIF_SIGPENDING|_TIF_NEED_RESCHED|_TIF_RESTOREALL)
+        andi.   r0,r9,(_TIF_SYSCALL_T_OR_A|_TIF_SIGPENDING|_TIF_NEED_RESCHED|_TIF_RESTOREALL|_TIF_RESTORE_SIGMASK)
         bne-    syscall_exit_work
         cmplw   0,r3,r8
         blt+    syscall_exit_cont
@@ -357,7 +357,7 @@ save_user_nvgprs_cont:
         lwz     r5,_MSR(r1)
         andi.   r5,r5,MSR_PR
         beq     ret_from_except
-        andi.   r0,r9,_TIF_SIGPENDING
+        andi.   r0,r9,_TIF_SIGPENDING|_TIF_RESTORE_SIGMASK
         beq     ret_from_except
         b       do_user_signal
 8:
@@ -683,7 +683,7 @@ user_exc_return:		/* r10 contains MSR_KERNEL here */
         /* Check current_thread_info()->flags */
         rlwinm  r9,r1,0,0,(31-THREAD_SHIFT)
         lwz     r9,TI_FLAGS(r9)
-        andi.   r0,r9,(_TIF_SIGPENDING|_TIF_NEED_RESCHED|_TIF_RESTOREALL)
+        andi.   r0,r9,(_TIF_SIGPENDING|_TIF_NEED_RESCHED|_TIF_RESTOREALL|_TIF_RESTORE_SIGMASK)
         bne     do_work
 
 restore_user:
@@ -917,7 +917,7 @@ recheck:
         lwz     r9,TI_FLAGS(r9)
         andi.   r0,r9,_TIF_NEED_RESCHED
         bne-    do_resched
-        andi.   r0,r9,_TIF_SIGPENDING
+        andi.   r0,r9,_TIF_SIGPENDING|_TIF_RESTORE_SIGMASK
         beq     restore_user
 do_user_signal:                 /* r10 contains MSR_KERNEL here */
         ori     r10,r10,MSR_EE
diff --git a/arch/powerpc/kernel/entry_64.S b/arch/powerpc/kernel/entry_64.S
index 542036318866..388f861b8ed1 100644
--- a/arch/powerpc/kernel/entry_64.S
+++ b/arch/powerpc/kernel/entry_64.S
@@ -160,7 +160,7 @@ syscall_exit:
         mtmsrd  r10,1
         ld      r9,TI_FLAGS(r12)
         li      r11,-_LAST_ERRNO
-        andi.   r0,r9,(_TIF_SYSCALL_T_OR_A|_TIF_SINGLESTEP|_TIF_SIGPENDING|_TIF_NEED_RESCHED|_TIF_RESTOREALL|_TIF_SAVE_NVGPRS|_TIF_NOERROR)
+        andi.   r0,r9,(_TIF_SYSCALL_T_OR_A|_TIF_SINGLESTEP|_TIF_SIGPENDING|_TIF_NEED_RESCHED|_TIF_RESTOREALL|_TIF_SAVE_NVGPRS|_TIF_NOERROR|_TIF_RESTORE_SIGMASK)
         bne-    syscall_exit_work
         cmpld   r3,r11
         ld      r5,_CCR(r1)
diff --git a/arch/powerpc/kernel/signal_32.c b/arch/powerpc/kernel/signal_32.c
index 7f0d5ce2567d..3747ab0dac3f 100644
--- a/arch/powerpc/kernel/signal_32.c
+++ b/arch/powerpc/kernel/signal_32.c
@@ -1128,7 +1128,7 @@ int do_signal(sigset_t *oldset, struct pt_regs *regs)
 {
         siginfo_t info;
         struct k_sigaction ka;
-        unsigned int frame, newsp;
+        unsigned int newsp;
         int signr, ret;
 
 #ifdef CONFIG_PPC32
@@ -1139,11 +1139,11 @@ int do_signal(sigset_t *oldset, struct pt_regs *regs)
         }
 #endif
 
-        if (!oldset)
+        if (test_thread_flag(TIF_RESTORE_SIGMASK))
+                oldset = &current->saved_sigmask;
+        else if (!oldset)
                 oldset = &current->blocked;
 
-        newsp = frame = 0;
-
         signr = get_signal_to_deliver(&info, &ka, regs, NULL);
 #ifdef CONFIG_PPC32
 no_signal:
@@ -1173,8 +1173,14 @@ no_signal:
                 }
         }
 
-        if (signr == 0)
+        if (signr == 0) {
+                /* No signal to deliver -- put the saved sigmask back */
+                if (test_thread_flag(TIF_RESTORE_SIGMASK)) {
+                        clear_thread_flag(TIF_RESTORE_SIGMASK);
+                        sigprocmask(SIG_SETMASK, &current->saved_sigmask, NULL);
+                }
                 return 0;               /* no signals delivered */
+        }
 
         if ((ka.sa.sa_flags & SA_ONSTACK) && current->sas_ss_size
             && !on_sig_stack(regs->gpr[1]))
@@ -1207,6 +1213,10 @@ no_signal:
                         sigaddset(&current->blocked, signr);
                 recalc_sigpending();
                 spin_unlock_irq(&current->sighand->siglock);
+                /* A signal was successfully delivered; the saved sigmask is in
+                   its frame, and we can clear the TIF_RESTORE_SIGMASK flag */
+                if (test_thread_flag(TIF_RESTORE_SIGMASK))
+                        clear_thread_flag(TIF_RESTORE_SIGMASK);
         }
 
         return ret;
diff --git a/arch/powerpc/kernel/signal_64.c b/arch/powerpc/kernel/signal_64.c
index a4a6812e815e..b3193116e686 100644
--- a/arch/powerpc/kernel/signal_64.c
+++ b/arch/powerpc/kernel/signal_64.c
@@ -520,11 +520,15 @@ int do_signal(sigset_t *oldset, struct pt_regs *regs)
         if (test_thread_flag(TIF_32BIT))
                 return do_signal32(oldset, regs);
 
-        if (!oldset)
+        if (test_thread_flag(TIF_RESTORE_SIGMASK))
+                oldset = &current->saved_sigmask;
+        else if (!oldset)
                 oldset = &current->blocked;
 
         signr = get_signal_to_deliver(&info, &ka, regs, NULL);
         if (signr > 0) {
+                int ret;
+
                 /* Whee!  Actually deliver the signal.  */
                 if (TRAP(regs) == 0x0C00)
                         syscall_restart(regs, &ka);
@@ -537,7 +541,14 @@ int do_signal(sigset_t *oldset, struct pt_regs *regs)
                 if (current->thread.dabr)
                         set_dabr(current->thread.dabr);
 
-                return handle_signal(signr, &ka, &info, oldset, regs);
+                ret = handle_signal(signr, &ka, &info, oldset, regs);
+
+                /* If a signal was successfully delivered, the saved sigmask is in
+                   its frame, and we can clear the TIF_RESTORE_SIGMASK flag */
+                if (ret && test_thread_flag(TIF_RESTORE_SIGMASK))
+                        clear_thread_flag(TIF_RESTORE_SIGMASK);
+
+                return ret;
         }
 
         if (TRAP(regs) == 0x0C00) {     /* System Call! */
@@ -553,6 +564,11 @@ int do_signal(sigset_t *oldset, struct pt_regs *regs)
                         regs->result = 0;
                 }
         }
+        /* No signal to deliver -- put the saved sigmask back */
+        if (test_thread_flag(TIF_RESTORE_SIGMASK)) {
+                clear_thread_flag(TIF_RESTORE_SIGMASK);
+                sigprocmask(SIG_SETMASK, &current->saved_sigmask, NULL);
+        }
 
         return 0;
 }
diff --git a/arch/powerpc/kernel/systbl.S b/arch/powerpc/kernel/systbl.S
index 68013179a503..007b15ee36d2 100644
--- a/arch/powerpc/kernel/systbl.S
+++ b/arch/powerpc/kernel/systbl.S
@@ -321,3 +321,5 @@ SYSCALL(inotify_add_watch)
 SYSCALL(inotify_rm_watch)
 SYSCALL(spu_run)
 SYSCALL(spu_create)
+COMPAT_SYS(pselect6)
+COMPAT_SYS(ppoll)