Fedora kernel-2.6.17-1.2142_FC4 patched with stable patch-2.6.17.4-vs2.0.2-rc26.diff
[linux-2.6.git] / arch / i386 / kernel / signal.c
index ea46d02..9ffe9bf 100644 (file)
 asmlinkage int
 sys_sigsuspend(int history0, int history1, old_sigset_t mask)
 {
-       struct pt_regs * regs = (struct pt_regs *) &history0;
-       sigset_t saveset;
-
        mask &= _BLOCKABLE;
        spin_lock_irq(&current->sighand->siglock);
-       saveset = current->blocked;
+       current->saved_sigmask = current->blocked;
        siginitset(&current->blocked, mask);
        recalc_sigpending();
        spin_unlock_irq(&current->sighand->siglock);
 
-       regs->eax = -EINTR;
-       while (1) {
-               current->state = TASK_INTERRUPTIBLE;
-               schedule();
-               if (do_signal(regs, &saveset))
-                       return -EINTR;
-       }
-}
-
-asmlinkage int
-sys_rt_sigsuspend(struct pt_regs regs)
-{
-       sigset_t saveset, newset;
-
-       /* XXX: Don't preclude handling different sized sigset_t's.  */
-       if (regs.ecx != sizeof(sigset_t))
-               return -EINVAL;
-
-       if (copy_from_user(&newset, (sigset_t __user *)regs.ebx, sizeof(newset)))
-               return -EFAULT;
-       sigdelsetmask(&newset, ~_BLOCKABLE);
-
-       spin_lock_irq(&current->sighand->siglock);
-       saveset = current->blocked;
-       current->blocked = newset;
-       recalc_sigpending();
-       spin_unlock_irq(&current->sighand->siglock);
-
-       regs.eax = -EINTR;
-       while (1) {
-               current->state = TASK_INTERRUPTIBLE;
-               schedule();
-               if (do_signal(&regs, &saveset))
-                       return -EINTR;
-       }
+       current->state = TASK_INTERRUPTIBLE;
+       schedule();
+       set_thread_flag(TIF_RESTORE_SIGMASK);
+       return -ERESTARTNOHAND;
 }
 
 asmlinkage int 
@@ -157,7 +123,8 @@ restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc, int *peax
          err |= __get_user(tmp, &sc->seg);                             \
          loadsegment(seg,tmp); }
 
-#define        FIX_EFLAGS      (X86_EFLAGS_AC | X86_EFLAGS_OF | X86_EFLAGS_DF | \
+#define        FIX_EFLAGS      (X86_EFLAGS_AC | X86_EFLAGS_RF |                 \
+                        X86_EFLAGS_OF | X86_EFLAGS_DF |                 \
                         X86_EFLAGS_TF | X86_EFLAGS_SF | X86_EFLAGS_ZF | \
                         X86_EFLAGS_AF | X86_EFLAGS_PF | X86_EFLAGS_CF)
 
@@ -278,9 +245,9 @@ setup_sigcontext(struct sigcontext __user *sc, struct _fpstate __user *fpstate,
        int tmp, err = 0;
 
        tmp = 0;
-       __asm__("movl %%gs,%0" : "=r"(tmp): "0"(tmp));
+       savesegment(gs, tmp);
        err |= __put_user(tmp, (unsigned int __user *)&sc->gs);
-       __asm__("movl %%fs,%0" : "=r"(tmp): "0"(tmp));
+       savesegment(fs, tmp);
        err |= __put_user(tmp, (unsigned int __user *)&sc->fs);
 
        err |= __put_user(regs->xes, (unsigned int __user *)&sc->es);
@@ -338,7 +305,11 @@ get_sigframe(struct k_sigaction *ka, struct pt_regs * regs, size_t frame_size)
                esp = (unsigned long) ka->sa.sa_restorer;
        }
 
-       return (void __user *)((esp - frame_size) & -8ul);
+       esp -= frame_size;
+       /* Align the stack pointer according to the i386 ABI,
+        * i.e. so that on function entry ((sp + 4) & 15) == 0. */
+       esp = ((esp + 4) & -16ul) - 4;
+       return (void __user *) esp;
 }
 
 /* These symbols are defined with the addresses in the vsyscall page.
@@ -346,8 +317,8 @@ get_sigframe(struct k_sigaction *ka, struct pt_regs * regs, size_t frame_size)
 extern void __user __kernel_sigreturn;
 extern void __user __kernel_rt_sigreturn;
 
-static void setup_frame(int sig, struct k_sigaction *ka,
-                       sigset_t *set, struct pt_regs * regs)
+static int setup_frame(int sig, struct k_sigaction *ka,
+                      sigset_t *set, struct pt_regs * regs)
 {
        void __user *restorer;
        struct sigframe __user *frame;
@@ -380,7 +351,7 @@ static void setup_frame(int sig, struct k_sigaction *ka,
                        goto give_sigsegv;
        }
 
-       restorer = &__kernel_sigreturn;
+       restorer = current->mm->context.vdso + (long)&__kernel_sigreturn;
        if (ka->sa.sa_flags & SA_RESTORER)
                restorer = ka->sa.sa_restorer;
 
@@ -429,13 +400,14 @@ static void setup_frame(int sig, struct k_sigaction *ka,
                current->comm, current->pid, frame, regs->eip, frame->pretcode);
 #endif
 
-       return;
+       return 0;
 
 give_sigsegv:
        force_sigsegv(sig, current);
+       return -EFAULT;
 }
 
-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)
 {
        void __user *restorer;
@@ -475,7 +447,7 @@ static void setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
                goto give_sigsegv;
 
        /* Set up to return from userspace.  */
-       restorer = &__kernel_rt_sigreturn;
+       restorer = current->mm->context.vdso + (long)&__kernel_rt_sigreturn;
        if (ka->sa.sa_flags & SA_RESTORER)
                restorer = ka->sa.sa_restorer;
        err |= __put_user(restorer, &frame->pretcode);
@@ -522,20 +494,23 @@ static void setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
                current->comm, current->pid, frame, regs->eip, frame->pretcode);
 #endif
 
-       return;
+       return 0;
 
 give_sigsegv:
        force_sigsegv(sig, current);
+       return -EFAULT;
 }
 
 /*
  * OK, we're invoking a handler
  */    
 
-static void
+static int
 handle_signal(unsigned long sig, siginfo_t *info, struct k_sigaction *ka,
              sigset_t *oldset, struct pt_regs * regs)
 {
+       int ret;
+
        /* Are we from a system call? */
        if (regs->orig_eax >= 0) {
                /* If so, check system call restarting.. */
@@ -569,17 +544,20 @@ handle_signal(unsigned long sig, siginfo_t *info, struct k_sigaction *ka,
 
        /* Set up the stack frame */
        if (ka->sa.sa_flags & SA_SIGINFO)
-               setup_rt_frame(sig, ka, info, oldset, regs);
+               ret = setup_rt_frame(sig, ka, info, oldset, regs);
        else
-               setup_frame(sig, ka, oldset, regs);
+               ret = setup_frame(sig, ka, oldset, regs);
 
-       if (!(ka->sa.sa_flags & SA_NODEFER)) {
+       if (ret == 0) {
                spin_lock_irq(&current->sighand->siglock);
                sigorsets(&current->blocked,&current->blocked,&ka->sa.sa_mask);
-               sigaddset(&current->blocked,sig);
+               if (!(ka->sa.sa_flags & SA_NODEFER))
+                       sigaddset(&current->blocked,sig);
                recalc_sigpending();
                spin_unlock_irq(&current->sighand->siglock);
        }
+
+       return ret;
 }
 
 /*
@@ -587,27 +565,27 @@ handle_signal(unsigned long sig, siginfo_t *info, struct k_sigaction *ka,
  * want to handle. Thus you cannot kill init even with a SIGKILL even by
  * mistake.
  */
-int fastcall do_signal(struct pt_regs *regs, sigset_t *oldset)
+static void fastcall do_signal(struct pt_regs *regs)
 {
        siginfo_t info;
        int signr;
        struct k_sigaction ka;
+       sigset_t *oldset;
 
        /*
         * We want the common case to go fast, which
         * is why we may in certain cases get here from
         * kernel mode. Just return without doing anything
-        * if so.
+        * if so.  vm86 regs switched out by assembly code
+        * before reaching here, so testing against kernel
+        * CS suffices.
         */
-       if ((regs->xcs & 3) != 3)
-               return 1;
+       if (!user_mode(regs))
+               return;
 
-       if (current->flags & PF_FREEZE) {
-               refrigerator(0);
-               goto no_signal;
-       }
-
-       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);
@@ -617,39 +595,54 @@ int fastcall do_signal(struct pt_regs *regs, sigset_t *oldset)
                 * have been cleared if the watchpoint triggered
                 * inside the kernel.
                 */
-               if (unlikely(current->thread.debugreg[7])) {
-                       loaddebug(&current->thread, 7);
-               }
+               if (unlikely(current->thread.debugreg[7]))
+                       set_debugreg(current->thread.debugreg[7], 7);
 
                /* Whee!  Actually deliver the signal.  */
-               handle_signal(signr, &info, &ka, oldset, regs);
-               return 1;
+               if (handle_signal(signr, &info, &ka, oldset, regs) == 0) {
+                       /* a signal was successfully delivered; the saved
+                        * sigmask will have been stored in the signal frame,
+                        * and will be restored by sigreturn, so we can simply
+                        * clear the TIF_RESTORE_SIGMASK flag */
+                       if (test_thread_flag(TIF_RESTORE_SIGMASK))
+                               clear_thread_flag(TIF_RESTORE_SIGMASK);
+               }
+
+               return;
        }
 
- no_signal:
        /* Did we come from a system call? */
        if (regs->orig_eax >= 0) {
                /* Restart the system call - no handlers present */
-               if (regs->eax == -ERESTARTNOHAND ||
-                   regs->eax == -ERESTARTSYS ||
-                   regs->eax == -ERESTARTNOINTR) {
+               switch (regs->eax) {
+               case -ERESTARTNOHAND:
+               case -ERESTARTSYS:
+               case -ERESTARTNOINTR:
                        regs->eax = regs->orig_eax;
                        regs->eip -= 2;
-               }
-               if (regs->eax == -ERESTART_RESTARTBLOCK){
+                       break;
+
+               case -ERESTART_RESTARTBLOCK:
                        regs->eax = __NR_restart_syscall;
                        regs->eip -= 2;
+                       break;
                }
        }
-       return 0;
+
+       /* if there's no signal to deliver, we just 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);
+       }
 }
 
 /*
  * notification of userspace execution resumption
- * - triggered by current->work.notify_resume
+ * - triggered by the TIF_WORK_MASK flags
  */
 __attribute__((regparm(3)))
-void do_notify_resume(struct pt_regs *regs, sigset_t *oldset,
+void do_notify_resume(struct pt_regs *regs, void *_unused,
                      __u32 thread_info_flags)
 {
        /* Pending single-step? */
@@ -657,9 +650,10 @@ void do_notify_resume(struct pt_regs *regs, sigset_t *oldset,
                regs->eflags |= TF_MASK;
                clear_thread_flag(TIF_SINGLESTEP);
        }
+
        /* deal with pending signal delivery */
-       if (thread_info_flags & _TIF_SIGPENDING)
-               do_signal(regs,oldset);
+       if (thread_info_flags & (_TIF_SIGPENDING | _TIF_RESTORE_SIGMASK))
+               do_signal(regs);
        
        clear_thread_flag(TIF_IRET);
 }