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-rw-r--r--arch/um/kernel/signal.c191
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 000000000000..4aa9808ba264
--- /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)));
+}