This commit was manufactured by cvs2svn to create branch 'vserver'.

[linux-2.6.git] / arch / um / kernel / signal.c

diff --git a/arch/um/kernel/signal.c b/arch/um/kernel/signal.c
new file mode 100644 (file)
index 0000000..2a32e5e
--- /dev/null
+++ b/arch/um/kernel/signal.c
@@ -0,0 +1,190 @@
+/*
+ * Copyright (C) 2000, 2001, 2002 Jeff Dike (jdike@karaya.com)
+ * Licensed under the GPL
+ */
+
+#include "linux/stddef.h"
+#include "linux/sys.h"
+#include "linux/sched.h"
+#include "linux/wait.h"
+#include "linux/kernel.h"
+#include "linux/smp_lock.h"
+#include "linux/module.h"
+#include "linux/slab.h"
+#include "linux/tty.h"
+#include "linux/binfmts.h"
+#include "linux/ptrace.h"
+#include "asm/signal.h"
+#include "asm/uaccess.h"
+#include "asm/unistd.h"
+#include "user_util.h"
+#include "asm/ucontext.h"
+#include "kern_util.h"
+#include "signal_kern.h"
+#include "kern.h"
+#include "frame_kern.h"
+#include "sigcontext.h"
+#include "mode.h"
+
+EXPORT_SYMBOL(block_signals);
+EXPORT_SYMBOL(unblock_signals);
+
+#define _S(nr) (1<<((nr)-1))
+
+#define _BLOCKABLE (~(_S(SIGKILL) | _S(SIGSTOP)))
+
+/*
+ * OK, we're invoking a handler
+ */
+static int handle_signal(struct pt_regs *regs, unsigned long signr,
+                        struct k_sigaction *ka, siginfo_t *info,
+                        sigset_t *oldset)
+{
+       unsigned long sp;
+       int err;
+
+       /* Always make any pending restarted system calls return -EINTR */
+       current_thread_info()->restart_block.fn = do_no_restart_syscall;
+
+       /* Did we come from a system call? */
+       if(PT_REGS_SYSCALL_NR(regs) >= 0){
+               /* If so, check system call restarting.. */
+               switch(PT_REGS_SYSCALL_RET(regs)){
+               case -ERESTART_RESTARTBLOCK:
+               case -ERESTARTNOHAND:
+                       PT_REGS_SYSCALL_RET(regs) = -EINTR;
+                       break;
+
+               case -ERESTARTSYS:
+                       if (!(ka->sa.sa_flags & SA_RESTART)) {
+                               PT_REGS_SYSCALL_RET(regs) = -EINTR;
+                               break;
+                       }
+               /* fallthrough */
+               case -ERESTARTNOINTR:
+                       PT_REGS_RESTART_SYSCALL(regs);
+                       PT_REGS_ORIG_SYSCALL(regs) = PT_REGS_SYSCALL_NR(regs);
+                       break;
+               }
+       }
+
+       sp = PT_REGS_SP(regs);
+       if((ka->sa.sa_flags & SA_ONSTACK) && (sas_ss_flags(sp) == 0))
+               sp = current->sas_ss_sp + current->sas_ss_size;
+
+#ifdef CONFIG_ARCH_HAS_SC_SIGNALS
+       if(!(ka->sa.sa_flags & SA_SIGINFO))
+               err = setup_signal_stack_sc(sp, signr, ka, regs, oldset);
+       else
+#endif
+               err = setup_signal_stack_si(sp, signr, ka, regs, info, oldset);
+
+       if(err){
+               spin_lock_irq(&current->sighand->siglock);
+               current->blocked = *oldset;
+               recalc_sigpending();
+               spin_unlock_irq(&current->sighand->siglock);
+               force_sigsegv(signr, current);
+       } else {
+               spin_lock_irq(&current->sighand->siglock);
+               sigorsets(&current->blocked, &current->blocked,
+                         &ka->sa.sa_mask);
+                if(!(ka->sa.sa_flags & SA_NODEFER))
+                       sigaddset(&current->blocked, signr);
+               recalc_sigpending();
+               spin_unlock_irq(&current->sighand->siglock);
+       }
+
+       return err;
+}
+
+static int kern_do_signal(struct pt_regs *regs)
+{
+       struct k_sigaction ka_copy;
+       siginfo_t info;
+       sigset_t *oldset;
+       int sig, handled_sig = 0;
+
+       if (test_thread_flag(TIF_RESTORE_SIGMASK))
+               oldset = &current->saved_sigmask;
+       else
+               oldset = &current->blocked;
+
+       while((sig = get_signal_to_deliver(&info, &ka_copy, regs, NULL)) > 0){
+               handled_sig = 1;
+               /* Whee!  Actually deliver the signal.  */
+               if(!handle_signal(regs, sig, &ka_copy, &info, oldset)){
+                       /* 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);
+                       break;
+               }
+       }
+
+       /* Did we come from a system call? */
+       if(!handled_sig && (PT_REGS_SYSCALL_NR(regs) >= 0)){
+               /* Restart the system call - no handlers present */
+               switch(PT_REGS_SYSCALL_RET(regs)){
+               case -ERESTARTNOHAND:
+               case -ERESTARTSYS:
+               case -ERESTARTNOINTR:
+                       PT_REGS_ORIG_SYSCALL(regs) = PT_REGS_SYSCALL_NR(regs);
+                       PT_REGS_RESTART_SYSCALL(regs);
+                       break;
+               case -ERESTART_RESTARTBLOCK:
+                       PT_REGS_ORIG_SYSCALL(regs) = __NR_restart_syscall;
+                       PT_REGS_RESTART_SYSCALL(regs);
+                       break;
+               }
+       }
+
+       /* This closes a way to execute a system call on the host.  If
+        * you set a breakpoint on a system call instruction and singlestep
+        * from it, the tracing thread used to PTRACE_SINGLESTEP the process
+        * rather than PTRACE_SYSCALL it, allowing the system call to execute
+        * on the host.  The tracing thread will check this flag and
+        * PTRACE_SYSCALL if necessary.
+        */
+       if(current->ptrace & PT_DTRACE)
+               current->thread.singlestep_syscall =
+                       is_syscall(PT_REGS_IP(&current->thread.regs));
+
+       /* if there's no signal to deliver, we just put the saved sigmask
+        * back */
+       if (!handled_sig && test_thread_flag(TIF_RESTORE_SIGMASK)) {
+               clear_thread_flag(TIF_RESTORE_SIGMASK);
+               sigprocmask(SIG_SETMASK, &current->saved_sigmask, NULL);
+       }
+       return(handled_sig);
+}
+
+int do_signal(void)
+{
+       return(kern_do_signal(&current->thread.regs));
+}
+
+/*
+ * Atomically swap in the new signal mask, and wait for a signal.
+ */
+long sys_sigsuspend(int history0, int history1, old_sigset_t mask)
+{
+       mask &= _BLOCKABLE;
+       spin_lock_irq(&current->sighand->siglock);
+       current->saved_sigmask = current->blocked;
+       siginitset(&current->blocked, mask);
+       recalc_sigpending();
+       spin_unlock_irq(&current->sighand->siglock);
+
+       current->state = TASK_INTERRUPTIBLE;
+       schedule();
+       set_thread_flag(TIF_RESTORE_SIGMASK);
+       return -ERESTARTNOHAND;
+}
+
+long sys_sigaltstack(const stack_t __user *uss, stack_t __user *uoss)
+{
+       return(do_sigaltstack(uss, uoss, PT_REGS_SP(&current->thread.regs)));
+}