1/*
  2 * Copyright (C) 2000 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
  3 * Licensed under the GPL
  4 */
  5
  6#include <linux/module.h>
  7#include <linux/ptrace.h>
  8#include <linux/sched.h>
  9#include <asm/siginfo.h>
 10#include <asm/signal.h>
 11#include <asm/unistd.h>
 12#include "frame_kern.h"
 13#include "kern_util.h"
 14
 15EXPORT_SYMBOL(block_signals);
 16EXPORT_SYMBOL(unblock_signals);
 17
 18/*
 19 * OK, we're invoking a handler
 20 */
 21static void handle_signal(struct pt_regs *regs, unsigned long signr,
 22			 struct k_sigaction *ka, siginfo_t *info)
 23{
 24	sigset_t *oldset = sigmask_to_save();
 
 25	unsigned long sp;
 26	int err;
 27
 
 
 
 28	/* Did we come from a system call? */
 29	if (PT_REGS_SYSCALL_NR(regs) >= 0) {
 30		/* If so, check system call restarting.. */
 31		switch (PT_REGS_SYSCALL_RET(regs)) {
 32		case -ERESTART_RESTARTBLOCK:
 33		case -ERESTARTNOHAND:
 34			PT_REGS_SYSCALL_RET(regs) = -EINTR;
 35			break;
 36
 37		case -ERESTARTSYS:
 38			if (!(ka->sa.sa_flags & SA_RESTART)) {
 39				PT_REGS_SYSCALL_RET(regs) = -EINTR;
 40				break;
 41			}
 42		/* fallthrough */
 43		case -ERESTARTNOINTR:
 44			PT_REGS_RESTART_SYSCALL(regs);
 45			PT_REGS_ORIG_SYSCALL(regs) = PT_REGS_SYSCALL_NR(regs);
 46			break;
 47		}
 48	}
 49
 50	sp = PT_REGS_SP(regs);
 51	if ((ka->sa.sa_flags & SA_ONSTACK) && (sas_ss_flags(sp) == 0))
 52		sp = current->sas_ss_sp + current->sas_ss_size;
 53
 54#ifdef CONFIG_ARCH_HAS_SC_SIGNALS
 55	if (!(ka->sa.sa_flags & SA_SIGINFO))
 56		err = setup_signal_stack_sc(sp, signr, ka, regs, oldset);
 57	else
 58#endif
 59		err = setup_signal_stack_si(sp, signr, ka, regs, info, oldset);
 60
 61	if (err)
 62		force_sigsegv(signr, current);
 63	else
 64		signal_delivered(signr, info, ka, regs, 0);
 65}
 66
 67static int kern_do_signal(struct pt_regs *regs)
 68{
 69	struct k_sigaction ka_copy;
 70	siginfo_t info;
 71	int sig, handled_sig = 0;
 72
 73	while ((sig = get_signal_to_deliver(&info, &ka_copy, regs, NULL)) > 0) {
 74		handled_sig = 1;
 75		/* Whee!  Actually deliver the signal.  */
 76		handle_signal(regs, sig, &ka_copy, &info);
 77	}
 78
 79	/* Did we come from a system call? */
 80	if (!handled_sig && (PT_REGS_SYSCALL_NR(regs) >= 0)) {
 81		/* Restart the system call - no handlers present */
 82		switch (PT_REGS_SYSCALL_RET(regs)) {
 83		case -ERESTARTNOHAND:
 84		case -ERESTARTSYS:
 85		case -ERESTARTNOINTR:
 86			PT_REGS_ORIG_SYSCALL(regs) = PT_REGS_SYSCALL_NR(regs);
 87			PT_REGS_RESTART_SYSCALL(regs);
 88			break;
 89		case -ERESTART_RESTARTBLOCK:
 90			PT_REGS_ORIG_SYSCALL(regs) = __NR_restart_syscall;
 91			PT_REGS_RESTART_SYSCALL(regs);
 92			break;
 93		}
 94	}
 95
 96	/*
 97	 * This closes a way to execute a system call on the host.  If
 98	 * you set a breakpoint on a system call instruction and singlestep
 99	 * from it, the tracing thread used to PTRACE_SINGLESTEP the process
100	 * rather than PTRACE_SYSCALL it, allowing the system call to execute
101	 * on the host.  The tracing thread will check this flag and
102	 * PTRACE_SYSCALL if necessary.
103	 */
104	if (current->ptrace & PT_DTRACE)
105		current->thread.singlestep_syscall =
106			is_syscall(PT_REGS_IP(&current->thread.regs));
107
108	/*
109	 * if there's no signal to deliver, we just put the saved sigmask
110	 * back
111	 */
112	if (!handled_sig)
113		restore_saved_sigmask();
114	return handled_sig;
115}
116
117int do_signal(void)
118{
119	return kern_do_signal(&current->thread.regs);
120}
121
122/*
123 * Atomically swap in the new signal mask, and wait for a signal.
124 */
125long sys_sigsuspend(int history0, int history1, old_sigset_t mask)
126{
127	sigset_t blocked;
128	siginitset(&blocked, mask);
129	return sigsuspend(&blocked);
130}
131
132long sys_sigaltstack(const stack_t __user *uss, stack_t __user *uoss)
133{
134	return do_sigaltstack(uss, uoss, PT_REGS_SP(&current->thread.regs));
135}

  1/*
  2 * Copyright (C) 2000 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
  3 * Licensed under the GPL
  4 */
  5
  6#include <linux/module.h>
  7#include <linux/ptrace.h>
  8#include <linux/sched.h>
  9#include <asm/siginfo.h>
 10#include <asm/signal.h>
 11#include <asm/unistd.h>
 12#include <frame_kern.h>
 13#include <kern_util.h>
 14
 15EXPORT_SYMBOL(block_signals);
 16EXPORT_SYMBOL(unblock_signals);
 17
 18/*
 19 * OK, we're invoking a handler
 20 */
 21static void handle_signal(struct pt_regs *regs, unsigned long signr,
 22			 struct k_sigaction *ka, struct siginfo *info)
 23{
 24	sigset_t *oldset = sigmask_to_save();
 25	int singlestep = 0;
 26	unsigned long sp;
 27	int err;
 28
 29	if ((current->ptrace & PT_DTRACE) && (current->ptrace & PT_PTRACED))
 30		singlestep = 1;
 31
 32	/* Did we come from a system call? */
 33	if (PT_REGS_SYSCALL_NR(regs) >= 0) {
 34		/* If so, check system call restarting.. */
 35		switch (PT_REGS_SYSCALL_RET(regs)) {
 36		case -ERESTART_RESTARTBLOCK:
 37		case -ERESTARTNOHAND:
 38			PT_REGS_SYSCALL_RET(regs) = -EINTR;
 39			break;
 40
 41		case -ERESTARTSYS:
 42			if (!(ka->sa.sa_flags & SA_RESTART)) {
 43				PT_REGS_SYSCALL_RET(regs) = -EINTR;
 44				break;
 45			}
 46		/* fallthrough */
 47		case -ERESTARTNOINTR:
 48			PT_REGS_RESTART_SYSCALL(regs);
 49			PT_REGS_ORIG_SYSCALL(regs) = PT_REGS_SYSCALL_NR(regs);
 50			break;
 51		}
 52	}
 53
 54	sp = PT_REGS_SP(regs);
 55	if ((ka->sa.sa_flags & SA_ONSTACK) && (sas_ss_flags(sp) == 0))
 56		sp = current->sas_ss_sp + current->sas_ss_size;
 57
 58#ifdef CONFIG_ARCH_HAS_SC_SIGNALS
 59	if (!(ka->sa.sa_flags & SA_SIGINFO))
 60		err = setup_signal_stack_sc(sp, signr, ka, regs, oldset);
 61	else
 62#endif
 63		err = setup_signal_stack_si(sp, signr, ka, regs, info, oldset);
 64
 65	if (err)
 66		force_sigsegv(signr, current);
 67	else
 68		signal_delivered(signr, info, ka, regs, singlestep);
 69}
 70
 71static int kern_do_signal(struct pt_regs *regs)
 72{
 73	struct k_sigaction ka_copy;
 74	struct siginfo info;
 75	int sig, handled_sig = 0;
 76
 77	while ((sig = get_signal_to_deliver(&info, &ka_copy, regs, NULL)) > 0) {
 78		handled_sig = 1;
 79		/* Whee!  Actually deliver the signal.  */
 80		handle_signal(regs, sig, &ka_copy, &info);
 81	}
 82
 83	/* Did we come from a system call? */
 84	if (!handled_sig && (PT_REGS_SYSCALL_NR(regs) >= 0)) {
 85		/* Restart the system call - no handlers present */
 86		switch (PT_REGS_SYSCALL_RET(regs)) {
 87		case -ERESTARTNOHAND:
 88		case -ERESTARTSYS:
 89		case -ERESTARTNOINTR:
 90			PT_REGS_ORIG_SYSCALL(regs) = PT_REGS_SYSCALL_NR(regs);
 91			PT_REGS_RESTART_SYSCALL(regs);
 92			break;
 93		case -ERESTART_RESTARTBLOCK:
 94			PT_REGS_ORIG_SYSCALL(regs) = __NR_restart_syscall;
 95			PT_REGS_RESTART_SYSCALL(regs);
 96			break;
 97		}
 98	}
 99
100	/*
101	 * This closes a way to execute a system call on the host.  If
102	 * you set a breakpoint on a system call instruction and singlestep
103	 * from it, the tracing thread used to PTRACE_SINGLESTEP the process
104	 * rather than PTRACE_SYSCALL it, allowing the system call to execute
105	 * on the host.  The tracing thread will check this flag and
106	 * PTRACE_SYSCALL if necessary.
107	 */
108	if (current->ptrace & PT_DTRACE)
109		current->thread.singlestep_syscall =
110			is_syscall(PT_REGS_IP(&current->thread.regs));
111
112	/*
113	 * if there's no signal to deliver, we just put the saved sigmask
114	 * back
115	 */
116	if (!handled_sig)
117		restore_saved_sigmask();
118	return handled_sig;
119}
120
121int do_signal(void)
122{
123	return kern_do_signal(&current->thread.regs);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
124}