Merge rsync://rsync.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6

1 files changed, 191 insertions, 0 deletions

diff --git a/arch/um/kernel/signal.c b/arch/um/kernel/signal.c
new file mode 100644
index 00000000000..4aa9808ba26
--- /dev/null
+++ b/arch/um/kernel/signal.c
@@ -0,0 +1,191 @@
+/*
+ * Copyright (C) 2000, 2001, 2002 Jeff Dike (jdike@karaya.com)
+ * Licensed under the GPL
+ */
+
+#include "linux/config.h"
+#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)));
+}