5 files changed, 141 insertions, 210 deletions

diff --git a/arch/m68k/include/asm/sun3_pgtable.h b/arch/m68k/include/asm/sun3_pgtable.h
index cf5fad9b525..f55aa04161e 100644
--- a/arch/m68k/include/asm/sun3_pgtable.h
+++ b/arch/m68k/include/asm/sun3_pgtable.h
@@ -217,9 +217,8 @@ static inline pte_t pgoff_to_pte(unsigned off)
 /* Find an entry in the third-level pagetable. */
 #define pte_index(address) ((address >> PAGE_SHIFT) & (PTRS_PER_PTE-1))
 #define pte_offset_kernel(pmd, address) ((pte_t *) __pmd_page(*pmd) + pte_index(address))
-/* FIXME: should we bother with kmap() here? */
-#define pte_offset_map(pmd, address) ((pte_t *)kmap(pmd_page(*pmd)) + pte_index(address))
-#define pte_unmap(pte) kunmap(pte)
+#define pte_offset_map(pmd, address) ((pte_t *)page_address(pmd_page(*pmd)) + pte_index(address))
+#define pte_unmap(pte) do { } while (0)
 
 /* Macros to (de)construct the fake PTEs representing swap pages. */
 #define __swp_type(x)           ((x).val & 0x7F)
diff --git a/arch/m68k/include/asm/thread_info.h b/arch/m68k/include/asm/thread_info.h
index 1da5d53a00e..790988967ba 100644
--- a/arch/m68k/include/asm/thread_info.h
+++ b/arch/m68k/include/asm/thread_info.h
@@ -104,5 +104,6 @@ static inline struct thread_info *current_thread_info(void)
 #define TIF_SYSCALL_TRACE       15      /* syscall trace active */
 #define TIF_MEMDIE              16      /* is terminating due to OOM killer */
 #define TIF_FREEZE              17      /* thread is freezing for suspend */
+#define TIF_RESTORE_SIGMASK     18      /* restore signal mask in do_signal */
 
 #endif  /* _ASM_M68K_THREAD_INFO_H */
diff --git a/arch/m68k/include/asm/unistd.h b/arch/m68k/include/asm/unistd.h
index b43b36beafe..26d851d385b 100644
--- a/arch/m68k/include/asm/unistd.h
+++ b/arch/m68k/include/asm/unistd.h
@@ -373,6 +373,7 @@
 #define __ARCH_WANT_SYS_SIGPENDING
 #define __ARCH_WANT_SYS_SIGPROCMASK
 #define __ARCH_WANT_SYS_RT_SIGACTION
+#define __ARCH_WANT_SYS_RT_SIGSUSPEND
 
 /*
  * "Conditional" syscalls
diff --git a/arch/m68k/kernel/entry.S b/arch/m68k/kernel/entry.S
index 6360c437dcf..1559dea36e5 100644
--- a/arch/m68k/kernel/entry.S
+++ b/arch/m68k/kernel/entry.S
@@ -99,7 +99,10 @@ do_trace_exit:
         jra     .Lret_from_exception
 
 ENTRY(ret_from_signal)
-        RESTORE_SWITCH_STACK
+        tstb    %curptr@(TASK_INFO+TINFO_FLAGS+2)
+        jge     1f
+        jbsr    syscall_trace
+1:      RESTORE_SWITCH_STACK
         addql   #4,%sp
 /* on 68040 complete pending writebacks if any */
 #ifdef CONFIG_M68040
@@ -174,16 +177,11 @@ do_signal_return:
         subql   #4,%sp                  | dummy return address
         SAVE_SWITCH_STACK
         pea     %sp@(SWITCH_STACK_SIZE)
-        clrl    %sp@-
         bsrl    do_signal
-        addql   #8,%sp
+        addql   #4,%sp
         RESTORE_SWITCH_STACK
         addql   #4,%sp
-        tstl    %d0
-        jeq     resume_userspace
-        | when single stepping into handler stop at the first insn
-        btst    #6,%curptr@(TASK_INFO+TINFO_FLAGS+2)
-        jeq     resume_userspace
+        jbra    resume_userspace
 
 do_delayed_trace:
         bclr    #7,%sp@(PT_OFF_SR)      | clear trace bit in SR
@@ -290,22 +288,6 @@ ENTRY(sys_vfork)
         RESTORE_SWITCH_STACK
         rts
 
-ENTRY(sys_sigsuspend)
-        SAVE_SWITCH_STACK
-        pea     %sp@(SWITCH_STACK_SIZE)
-        jbsr    do_sigsuspend
-        addql   #4,%sp
-        RESTORE_SWITCH_STACK
-        rts
-
-ENTRY(sys_rt_sigsuspend)
-        SAVE_SWITCH_STACK
-        pea     %sp@(SWITCH_STACK_SIZE)
-        jbsr    do_rt_sigsuspend
-        addql   #4,%sp
-        RESTORE_SWITCH_STACK
-        rts
-
 ENTRY(sys_sigreturn)
         SAVE_SWITCH_STACK
         jbsr    do_sigreturn
diff --git a/arch/m68k/kernel/signal.c b/arch/m68k/kernel/signal.c
index 4b387538706..d12c3b0d9e4 100644
--- a/arch/m68k/kernel/signal.c
+++ b/arch/m68k/kernel/signal.c
@@ -51,8 +51,6 @@
 
 #define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP)))
 
-asmlinkage int do_signal(sigset_t *oldset, struct pt_regs *regs);
-
 const int frame_extra_sizes[16] = {
   [1]   = -1, /* sizeof(((struct frame *)0)->un.fmt1), */
   [2]   = sizeof(((struct frame *)0)->un.fmt2),
@@ -74,51 +72,21 @@ const int frame_extra_sizes[16] = {
 /*
  * Atomically swap in the new signal mask, and wait for a signal.
  */
-asmlinkage int do_sigsuspend(struct pt_regs *regs)
+asmlinkage int
+sys_sigsuspend(int unused0, int unused1, old_sigset_t mask)
 {
-        old_sigset_t mask = regs->d3;
-        sigset_t saveset;
-
         mask &= _BLOCKABLE;
-        saveset = current->blocked;
+        spin_lock_irq(&current->sighand->siglock);
+        current->saved_sigmask = current->blocked;
         siginitset(&current->blocked, mask);
         recalc_sigpending();
+        spin_unlock_irq(&current->sighand->siglock);
 
-        regs->d0 = -EINTR;
-        while (1) {
-                current->state = TASK_INTERRUPTIBLE;
-                schedule();
-                if (do_signal(&saveset, regs))
-                        return -EINTR;
-        }
-}
-
-asmlinkage int
-do_rt_sigsuspend(struct pt_regs *regs)
-{
-        sigset_t __user *unewset = (sigset_t __user *)regs->d1;
-        size_t sigsetsize = (size_t)regs->d2;
-        sigset_t saveset, newset;
-
-        /* XXX: Don't preclude handling different sized sigset_t's.  */
-        if (sigsetsize != sizeof(sigset_t))
-                return -EINVAL;
+        current->state = TASK_INTERRUPTIBLE;
+        schedule();
+        set_restore_sigmask();
 
-        if (copy_from_user(&newset, unewset, sizeof(newset)))
-                return -EFAULT;
-        sigdelsetmask(&newset, ~_BLOCKABLE);
-
-        saveset = current->blocked;
-        current->blocked = newset;
-        recalc_sigpending();
-
-        regs->d0 = -EINTR;
-        while (1) {
-                current->state = TASK_INTERRUPTIBLE;
-                schedule();
-                if (do_signal(&saveset, regs))
-                        return -EINTR;
-        }
+        return -ERESTARTNOHAND;
 }
 
 asmlinkage int
@@ -132,10 +100,10 @@ sys_sigaction(int sig, const struct old_sigaction __user *act,
                 old_sigset_t mask;
                 if (!access_ok(VERIFY_READ, act, sizeof(*act)) ||
                     __get_user(new_ka.sa.sa_handler, &act->sa_handler) ||
-                    __get_user(new_ka.sa.sa_restorer, &act->sa_restorer))
+                    __get_user(new_ka.sa.sa_restorer, &act->sa_restorer) ||
+                    __get_user(new_ka.sa.sa_flags, &act->sa_flags) ||
+                    __get_user(mask, &act->sa_mask))
                         return -EFAULT;
-                __get_user(new_ka.sa.sa_flags, &act->sa_flags);
-                __get_user(mask, &act->sa_mask);
                 siginitset(&new_ka.sa.sa_mask, mask);
         }
 
@@ -144,10 +112,10 @@ sys_sigaction(int sig, const struct old_sigaction __user *act,
         if (!ret && oact) {
                 if (!access_ok(VERIFY_WRITE, oact, sizeof(*oact)) ||
                     __put_user(old_ka.sa.sa_handler, &oact->sa_handler) ||
-                    __put_user(old_ka.sa.sa_restorer, &oact->sa_restorer))
+                    __put_user(old_ka.sa.sa_restorer, &oact->sa_restorer) ||
+                    __put_user(old_ka.sa.sa_flags, &oact->sa_flags) ||
+                    __put_user(old_ka.sa.sa_mask.sig[0], &oact->sa_mask))
                         return -EFAULT;
-                __put_user(old_ka.sa.sa_flags, &oact->sa_flags);
-                __put_user(old_ka.sa.sa_mask.sig[0], &oact->sa_mask);
         }
 
         return ret;
@@ -318,36 +286,10 @@ out:
         return err;
 }
 
-static inline int
-restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *usc, void __user *fp,
-                   int *pd0)
+static int mangle_kernel_stack(struct pt_regs *regs, int formatvec,
+                               void __user *fp)
 {
-        int fsize, formatvec;
-        struct sigcontext context;
-        int err;
-
-        /* Always make any pending restarted system calls return -EINTR */
-        current_thread_info()->restart_block.fn = do_no_restart_syscall;
-
-        /* get previous context */
-        if (copy_from_user(&context, usc, sizeof(context)))
-                goto badframe;
-
-        /* restore passed registers */
-        regs->d1 = context.sc_d1;
-        regs->a0 = context.sc_a0;
-        regs->a1 = context.sc_a1;
-        regs->sr = (regs->sr & 0xff00) | (context.sc_sr & 0xff);
-        regs->pc = context.sc_pc;
-        regs->orig_d0 = -1;             /* disable syscall checks */
-        wrusp(context.sc_usp);
-        formatvec = context.sc_formatvec;
-        regs->format = formatvec >> 12;
-        regs->vector = formatvec & 0xfff;
-
-        err = restore_fpu_state(&context);
-
-        fsize = frame_extra_sizes[regs->format];
+        int fsize = frame_extra_sizes[formatvec >> 12];
         if (fsize < 0) {
                 /*
                  * user process trying to return with weird frame format
@@ -355,16 +297,22 @@ restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *usc, void __u
 #ifdef DEBUG
                 printk("user process returning with weird frame format\n");
 #endif
-                goto badframe;
+                return 1;
         }
+        if (!fsize) {
+                regs->format = formatvec >> 12;
+                regs->vector = formatvec & 0xfff;
+        } else {
+                struct switch_stack *sw = (struct switch_stack *)regs - 1;
+                unsigned long buf[fsize / 2]; /* yes, twice as much */
 
-        /* OK.  Make room on the supervisor stack for the extra junk,
-         * if necessary.
-         */
+                /* that'll make sure that expansion won't crap over data */
+                if (copy_from_user(buf + fsize / 4, fp, fsize))
+                        return 1;
 
-        if (fsize) {
-                struct switch_stack *sw = (struct switch_stack *)regs - 1;
-                regs->d0 = context.sc_d0;
+                /* point of no return */
+                regs->format = formatvec >> 12;
+                regs->vector = formatvec & 0xfff;
 #define frame_offset (sizeof(struct pt_regs)+sizeof(struct switch_stack))
                 __asm__ __volatile__
                         ("   movel %0,%/a0\n\t"
@@ -376,30 +324,50 @@ restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *usc, void __u
                          "   lea %/sp@(%c3),%/a0\n\t" /* add offset of fmt */
                          "   lsrl  #2,%1\n\t"
                          "   subql #1,%1\n\t"
-                         "2: movesl %4@+,%2\n\t"
-                         "3: movel %2,%/a0@+\n\t"
+                         /* copy to the gap we'd made */
+                         "2: movel %4@+,%/a0@+\n\t"
                          "   dbra %1,2b\n\t"
                          "   bral ret_from_signal\n"
-                         "4:\n"
-                         ".section __ex_table,\"a\"\n"
-                         "   .align 4\n"
-                         "   .long 2b,4b\n"
-                         "   .long 3b,4b\n"
-                         ".previous"
                          : /* no outputs, it doesn't ever return */
                          : "a" (sw), "d" (fsize), "d" (frame_offset/4-1),
-                           "n" (frame_offset), "a" (fp)
+                           "n" (frame_offset), "a" (buf + fsize/4)
                          : "a0");
 #undef frame_offset
-                /*
-                 * If we ever get here an exception occurred while
-                 * building the above stack-frame.
-                 */
-                goto badframe;
         }
+        return 0;
+}
 
-        *pd0 = context.sc_d0;
-        return err;
+static inline int
+restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *usc, void __user *fp)
+{
+        int formatvec;
+        struct sigcontext context;
+        int err;
+
+        /* Always make any pending restarted system calls return -EINTR */
+        current_thread_info()->restart_block.fn = do_no_restart_syscall;
+
+        /* get previous context */
+        if (copy_from_user(&context, usc, sizeof(context)))
+                goto badframe;
+
+        /* restore passed registers */
+        regs->d0 = context.sc_d0;
+        regs->d1 = context.sc_d1;
+        regs->a0 = context.sc_a0;
+        regs->a1 = context.sc_a1;
+        regs->sr = (regs->sr & 0xff00) | (context.sc_sr & 0xff);
+        regs->pc = context.sc_pc;
+        regs->orig_d0 = -1;             /* disable syscall checks */
+        wrusp(context.sc_usp);
+        formatvec = context.sc_formatvec;
+
+        err = restore_fpu_state(&context);
+
+        if (err || mangle_kernel_stack(regs, formatvec, fp))
+                goto badframe;
+
+        return 0;
 
 badframe:
         return 1;
@@ -407,9 +375,9 @@ badframe:
 
 static inline int
 rt_restore_ucontext(struct pt_regs *regs, struct switch_stack *sw,
-                    struct ucontext __user *uc, int *pd0)
+                    struct ucontext __user *uc)
 {
-        int fsize, temp;
+        int temp;
         greg_t __user *gregs = uc->uc_mcontext.gregs;
         unsigned long usp;
         int err;
@@ -443,65 +411,16 @@ rt_restore_ucontext(struct pt_regs *regs, struct switch_stack *sw,
         regs->sr = (regs->sr & 0xff00) | (temp & 0xff);
         regs->orig_d0 = -1;             /* disable syscall checks */
         err |= __get_user(temp, &uc->uc_formatvec);
-        regs->format = temp >> 12;
-        regs->vector = temp & 0xfff;
 
         err |= rt_restore_fpu_state(uc);
 
-        if (do_sigaltstack(&uc->uc_stack, NULL, usp) == -EFAULT)
+        if (err || do_sigaltstack(&uc->uc_stack, NULL, usp) == -EFAULT)
                 goto badframe;
 
-        fsize = frame_extra_sizes[regs->format];
-        if (fsize < 0) {
-                /*
-                 * user process trying to return with weird frame format
-                 */
-#ifdef DEBUG
-                printk("user process returning with weird frame format\n");
-#endif
+        if (mangle_kernel_stack(regs, temp, &uc->uc_extra))
                 goto badframe;
-        }
-
-        /* OK.  Make room on the supervisor stack for the extra junk,
-         * if necessary.
-         */
 
-        if (fsize) {
-#define frame_offset (sizeof(struct pt_regs)+sizeof(struct switch_stack))
-                __asm__ __volatile__
-                        ("   movel %0,%/a0\n\t"
-                         "   subl %1,%/a0\n\t"     /* make room on stack */
-                         "   movel %/a0,%/sp\n\t"  /* set stack pointer */
-                         /* move switch_stack and pt_regs */
-                         "1: movel %0@+,%/a0@+\n\t"
-                         "   dbra %2,1b\n\t"
-                         "   lea %/sp@(%c3),%/a0\n\t" /* add offset of fmt */
-                         "   lsrl  #2,%1\n\t"
-                         "   subql #1,%1\n\t"
-                         "2: movesl %4@+,%2\n\t"
-                         "3: movel %2,%/a0@+\n\t"
-                         "   dbra %1,2b\n\t"
-                         "   bral ret_from_signal\n"
-                         "4:\n"
-                         ".section __ex_table,\"a\"\n"
-                         "   .align 4\n"
-                         "   .long 2b,4b\n"
-                         "   .long 3b,4b\n"
-                         ".previous"
-                         : /* no outputs, it doesn't ever return */
-                         : "a" (sw), "d" (fsize), "d" (frame_offset/4-1),
-                           "n" (frame_offset), "a" (&uc->uc_extra)
-                         : "a0");
-#undef frame_offset
-                /*
-                 * If we ever get here an exception occurred while
-                 * building the above stack-frame.
-                 */
-                goto badframe;
-        }
-
-        *pd0 = regs->d0;
-        return err;
+        return 0;
 
 badframe:
         return 1;
@@ -514,7 +433,6 @@ asmlinkage int do_sigreturn(unsigned long __unused)
         unsigned long usp = rdusp();
         struct sigframe __user *frame = (struct sigframe __user *)(usp - 4);
         sigset_t set;
-        int d0;
 
         if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
                 goto badframe;
@@ -528,9 +446,9 @@ asmlinkage int do_sigreturn(unsigned long __unused)
         current->blocked = set;
         recalc_sigpending();
 
-        if (restore_sigcontext(regs, &frame->sc, frame + 1, &d0))
+        if (restore_sigcontext(regs, &frame->sc, frame + 1))
                 goto badframe;
-        return d0;
+        return regs->d0;
 
 badframe:
         force_sig(SIGSEGV, current);
@@ -544,7 +462,6 @@ asmlinkage int do_rt_sigreturn(unsigned long __unused)
         unsigned long usp = rdusp();
         struct rt_sigframe __user *frame = (struct rt_sigframe __user *)(usp - 4);
         sigset_t set;
-        int d0;
 
         if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
                 goto badframe;
@@ -555,9 +472,9 @@ asmlinkage int do_rt_sigreturn(unsigned long __unused)
         current->blocked = set;
         recalc_sigpending();
 
-        if (rt_restore_ucontext(regs, sw, &frame->uc, &d0))
+        if (rt_restore_ucontext(regs, sw, &frame->uc))
                 goto badframe;
-        return d0;
+        return regs->d0;
 
 badframe:
         force_sig(SIGSEGV, current);
@@ -775,7 +692,7 @@ get_sigframe(struct k_sigaction *ka, struct pt_regs *regs, size_t frame_size)
         return (void __user *)((usp - frame_size) & -8UL);
 }
 
-static void setup_frame (int sig, struct k_sigaction *ka,
+static int setup_frame (int sig, struct k_sigaction *ka,
                          sigset_t *set, struct pt_regs *regs)
 {
         struct sigframe __user *frame;
@@ -793,10 +710,8 @@ static void setup_frame (int sig, struct k_sigaction *ka,
 
         frame = get_sigframe(ka, regs, sizeof(*frame) + fsize);
 
-        if (fsize) {
+        if (fsize)
                 err |= copy_to_user (frame + 1, regs + 1, fsize);
-                regs->stkadj = fsize;
-        }
 
         err |= __put_user((current_thread_info()->exec_domain
                            && current_thread_info()->exec_domain->signal_invmap
@@ -826,11 +741,21 @@ static void setup_frame (int sig, struct k_sigaction *ka,
 
         push_cache ((unsigned long) &frame->retcode);
 
-        /* Set up registers for signal handler */
+        /*
+         * Set up registers for signal handler.  All the state we are about
+         * to destroy is successfully copied to sigframe.
+         */
         wrusp ((unsigned long) frame);
         regs->pc = (unsigned long) ka->sa.sa_handler;
 
-adjust_stack:
+        /*
+         * This is subtle; if we build more than one sigframe, all but the
+         * first one will see frame format 0 and have fsize == 0, so we won't
+         * screw stkadj.
+         */
+        if (fsize)
+                regs->stkadj = fsize;
+
         /* Prepare to skip over the extra stuff in the exception frame.  */
         if (regs->stkadj) {
                 struct pt_regs *tregs =
@@ -845,14 +770,14 @@ adjust_stack:
                 tregs->pc = regs->pc;
                 tregs->sr = regs->sr;
         }
-        return;
+        return 0;
 
 give_sigsegv:
         force_sigsegv(sig, current);
-        goto adjust_stack;
+        return err;
 }
 
-static void setup_rt_frame (int sig, struct k_sigaction *ka, siginfo_t *info,
+static int setup_rt_frame (int sig, struct k_sigaction *ka, siginfo_t *info,
                             sigset_t *set, struct pt_regs *regs)
 {
         struct rt_sigframe __user *frame;
@@ -869,10 +794,8 @@ static void setup_rt_frame (int sig, struct k_sigaction *ka, siginfo_t *info,
 
         frame = get_sigframe(ka, regs, sizeof(*frame));
 
-        if (fsize) {
+        if (fsize)
                 err |= copy_to_user (&frame->uc.uc_extra, regs + 1, fsize);
-                regs->stkadj = fsize;
-        }
 
         err |= __put_user((current_thread_info()->exec_domain
                            && current_thread_info()->exec_domain->signal_invmap
@@ -914,11 +837,21 @@ static void setup_rt_frame (int sig, struct k_sigaction *ka, siginfo_t *info,
 
         push_cache ((unsigned long) &frame->retcode);
 
-        /* Set up registers for signal handler */
+        /*
+         * Set up registers for signal handler.  All the state we are about
+         * to destroy is successfully copied to sigframe.
+         */
         wrusp ((unsigned long) frame);
         regs->pc = (unsigned long) ka->sa.sa_handler;
 
-adjust_stack:
+        /*
+         * This is subtle; if we build more than one sigframe, all but the
+         * first one will see frame format 0 and have fsize == 0, so we won't
+         * screw stkadj.
+         */
+        if (fsize)
+                regs->stkadj = fsize;
+
         /* Prepare to skip over the extra stuff in the exception frame.  */
         if (regs->stkadj) {
                 struct pt_regs *tregs =
@@ -933,11 +866,11 @@ adjust_stack:
                 tregs->pc = regs->pc;
                 tregs->sr = regs->sr;
         }
-        return;
+        return 0;
 
 give_sigsegv:
         force_sigsegv(sig, current);
-        goto adjust_stack;
+        return err;
 }
 
 static inline void
@@ -995,6 +928,7 @@ static void
 handle_signal(int sig, struct k_sigaction *ka, siginfo_t *info,
               sigset_t *oldset, struct pt_regs *regs)
 {
+        int err;
         /* are we from a system call? */
         if (regs->orig_d0 >= 0)
                 /* If so, check system call restarting.. */
@@ -1002,17 +936,24 @@ handle_signal(int sig, struct k_sigaction *ka, siginfo_t *info,
 
         /* set up the stack frame */
         if (ka->sa.sa_flags & SA_SIGINFO)
-                setup_rt_frame(sig, ka, info, oldset, regs);
+                err = setup_rt_frame(sig, ka, info, oldset, regs);
         else
-                setup_frame(sig, ka, oldset, regs);
+                err = setup_frame(sig, ka, oldset, regs);
 
-        if (ka->sa.sa_flags & SA_ONESHOT)
-                ka->sa.sa_handler = SIG_DFL;
+        if (err)
+                return;
 
         sigorsets(&current->blocked,&current->blocked,&ka->sa.sa_mask);
         if (!(ka->sa.sa_flags & SA_NODEFER))
                 sigaddset(&current->blocked,sig);
         recalc_sigpending();
+
+        if (test_thread_flag(TIF_DELAYED_TRACE)) {
+                regs->sr &= ~0x8000;
+                send_sig(SIGTRAP, current, 1);
+        }
+
+        clear_thread_flag(TIF_RESTORE_SIGMASK);
 }
 
 /*
@@ -1020,22 +961,25 @@ handle_signal(int sig, struct k_sigaction *ka, siginfo_t *info,
  * want to handle. Thus you cannot kill init even with a SIGKILL even by
  * mistake.
  */
-asmlinkage int do_signal(sigset_t *oldset, struct pt_regs *regs)
+asmlinkage void do_signal(struct pt_regs *regs)
 {
         siginfo_t info;
         struct k_sigaction ka;
         int signr;
+        sigset_t *oldset;
 
         current->thread.esp0 = (unsigned long) regs;
 
-        if (!oldset)
+        if (test_thread_flag(TIF_RESTORE_SIGMASK))
+                oldset = &current->saved_sigmask;
+        else
                 oldset = &current->blocked;
 
         signr = get_signal_to_deliver(&info, &ka, regs, NULL);
         if (signr > 0) {
                 /* Whee!  Actually deliver the signal.  */
                 handle_signal(signr, &ka, &info, oldset, regs);
-                return 1;
+                return;
         }
 
         /* Did we come from a system call? */
@@ -1043,5 +987,9 @@ asmlinkage int do_signal(sigset_t *oldset, struct pt_regs *regs)
                 /* Restart the system call - no handlers present */
                 handle_restart(regs, NULL, 0);
 
-        return 0;
+        /* If there's no signal to deliver, we just restore the saved mask.  */
+        if (test_thread_flag(TIF_RESTORE_SIGMASK)) {
+                clear_thread_flag(TIF_RESTORE_SIGMASK);
+                sigprocmask(SIG_SETMASK, &current->saved_sigmask, NULL);
+        }
 }