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

/* 
 * 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_SYSCALL_RET(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)));
}
Commit	Line	Data
1da177e4 LT	1	/*
	2	* Copyright (C) 2000, 2001, 2002 Jeff Dike (jdike@karaya.com)
	3	* Licensed under the GPL
	4	*/
	5
	6	#include "linux/config.h"
	7	#include "linux/stddef.h"
	8	#include "linux/sys.h"
	9	#include "linux/sched.h"
	10	#include "linux/wait.h"
	11	#include "linux/kernel.h"
	12	#include "linux/smp_lock.h"
	13	#include "linux/module.h"
	14	#include "linux/slab.h"
	15	#include "linux/tty.h"
	16	#include "linux/binfmts.h"
	17	#include "linux/ptrace.h"
	18	#include "asm/signal.h"
	19	#include "asm/uaccess.h"
	20	#include "asm/unistd.h"
	21	#include "user_util.h"
	22	#include "asm/ucontext.h"
	23	#include "kern_util.h"
	24	#include "signal_kern.h"
1da177e4 LT	25	#include "kern.h"
	26	#include "frame_kern.h"
	27	#include "sigcontext.h"
	28	#include "mode.h"
	29
	30	EXPORT_SYMBOL(block_signals);
	31	EXPORT_SYMBOL(unblock_signals);
	32
	33	#define _S(nr) (1<<((nr)-1))
	34
	35	#define _BLOCKABLE (~(_S(SIGKILL) \| _S(SIGSTOP)))
	36
	37	/*
	38	* OK, we're invoking a handler
	39	*/
	40	static int handle_signal(struct pt_regs *regs, unsigned long signr,
	41	struct k_sigaction ka, siginfo_t info,
	42	sigset_t *oldset)
	43	{
	44	unsigned long sp;
	45	int err;
	46
	47	/* Always make any pending restarted system calls return -EINTR */
	48	current_thread_info()->restart_block.fn = do_no_restart_syscall;
	49
	50	/* Did we come from a system call? */
	51	if(PT_REGS_SYSCALL_NR(regs) >= 0){
	52	/* If so, check system call restarting.. */
	53	switch(PT_REGS_SYSCALL_RET(regs)){
	54	case -ERESTART_RESTARTBLOCK:
	55	case -ERESTARTNOHAND:
	56	PT_REGS_SYSCALL_RET(regs) = -EINTR;
	57	break;
	58
	59	case -ERESTARTSYS:
	60	if (!(ka->sa.sa_flags & SA_RESTART)) {
	61	PT_REGS_SYSCALL_RET(regs) = -EINTR;
	62	break;
	63	}
	64	/* fallthrough */
	65	case -ERESTARTNOINTR:
	66	PT_REGS_RESTART_SYSCALL(regs);
	67	PT_REGS_ORIG_SYSCALL(regs) = PT_REGS_SYSCALL_NR(regs);
	68	break;
	69	}
	70	}
	71
	72	sp = PT_REGS_SP(regs);
	73	if((ka->sa.sa_flags & SA_ONSTACK) && (sas_ss_flags(sp) == 0))
	74	sp = current->sas_ss_sp + current->sas_ss_size;
	75
	76	#ifdef CONFIG_ARCH_HAS_SC_SIGNALS
	77	if(!(ka->sa.sa_flags & SA_SIGINFO))
	78	err = setup_signal_stack_sc(sp, signr, ka, regs, oldset);
	79	else
	80	#endif
	81	err = setup_signal_stack_si(sp, signr, ka, regs, info, oldset);
	82
	83	if(err){
	84	spin_lock_irq(&current->sighand->siglock);
	85	current->blocked = *oldset;
	86	recalc_sigpending();
	87	spin_unlock_irq(&current->sighand->siglock);
	88	force_sigsegv(signr, current);
69be8f18	89	} else {
1da177e4 LT	90	spin_lock_irq(&current->sighand->siglock);
	91	sigorsets(&current->blocked, &current->blocked,
	92	&ka->sa.sa_mask);
69be8f18 SR	93	if(!(ka->sa.sa_flags & SA_NODEFER))
69be8f18 SR	94	sigaddset(&current->blocked, signr);
1da177e4 LT	95	recalc_sigpending();
	96	spin_unlock_irq(&current->sighand->siglock);
	97	}
	98
	99	return err;
	100	}
	101
2fc10620	102	static int kern_do_signal(struct pt_regs *regs)
1da177e4 LT	103	{
	104	struct k_sigaction ka_copy;
	105	siginfo_t info;
2fc10620	106	sigset_t *oldset;
1da177e4 LT	107	int sig, handled_sig = 0;
1da177e4 LT	108
2fc10620 JD	109	if (test_thread_flag(TIF_RESTORE_SIGMASK))
	110	oldset = &current->saved_sigmask;
	111	else
	112	oldset = &current->blocked;
	113
1da177e4 LT	114	while((sig = get_signal_to_deliver(&info, &ka_copy, regs, NULL)) > 0){
	115	handled_sig = 1;
	116	/* Whee! Actually deliver the signal. */
2fc10620 JD	117	if(!handle_signal(regs, sig, &ka_copy, &info, oldset)){
	118	/* a signal was successfully delivered; the saved
	119	* sigmask will have been stored in the signal frame,
	120	* and will be restored by sigreturn, so we can simply
	121	* clear the TIF_RESTORE_SIGMASK flag */
	122	if (test_thread_flag(TIF_RESTORE_SIGMASK))
	123	clear_thread_flag(TIF_RESTORE_SIGMASK);
1da177e4	124	break;
2fc10620	125	}
1da177e4 LT	126	}
	127
	128	/* Did we come from a system call? */
	129	if(!handled_sig && (PT_REGS_SYSCALL_NR(regs) >= 0)){
	130	/* Restart the system call - no handlers present */
2fc10620 JD	131	switch(PT_REGS_SYSCALL_RET(regs)){
	132	case -ERESTARTNOHAND:
	133	case -ERESTARTSYS:
	134	case -ERESTARTNOINTR:
1da177e4 LT	135	PT_REGS_ORIG_SYSCALL(regs) = PT_REGS_SYSCALL_NR(regs);
1da177e4 LT	136	PT_REGS_RESTART_SYSCALL(regs);
2fc10620 JD	137	break;
2fc10620 JD	138	case -ERESTART_RESTARTBLOCK:
1da177e4 LT	139	PT_REGS_SYSCALL_RET(regs) = __NR_restart_syscall;
1da177e4 LT	140	PT_REGS_RESTART_SYSCALL(regs);
2fc10620	141	break;
1da177e4 LT	142	}
	143	}
	144
	145	/* This closes a way to execute a system call on the host. If
	146	* you set a breakpoint on a system call instruction and singlestep
	147	* from it, the tracing thread used to PTRACE_SINGLESTEP the process
	148	* rather than PTRACE_SYSCALL it, allowing the system call to execute
	149	* on the host. The tracing thread will check this flag and
	150	* PTRACE_SYSCALL if necessary.
	151	*/
	152	if(current->ptrace & PT_DTRACE)
	153	current->thread.singlestep_syscall =
	154	is_syscall(PT_REGS_IP(&current->thread.regs));
2fc10620 JD	155
	156	/* if there's no signal to deliver, we just put the saved sigmask
	157	* back */
	158	if (!handled_sig && test_thread_flag(TIF_RESTORE_SIGMASK)) {
	159	clear_thread_flag(TIF_RESTORE_SIGMASK);
	160	sigprocmask(SIG_SETMASK, &current->saved_sigmask, NULL);
	161	}
1da177e4 LT	162	return(handled_sig);
	163	}
	164
	165	int do_signal(void)
	166	{
2fc10620	167	return(kern_do_signal(&current->thread.regs));
1da177e4 LT	168	}
	169
	170	/*
	171	* Atomically swap in the new signal mask, and wait for a signal.
	172	*/
	173	long sys_sigsuspend(int history0, int history1, old_sigset_t mask)
	174	{
1da177e4 LT	175	mask &= _BLOCKABLE;
1da177e4 LT	176	spin_lock_irq(&current->sighand->siglock);
2fc10620	177	current->saved_sigmask = current->blocked;
1da177e4 LT	178	siginitset(&current->blocked, mask);
	179	recalc_sigpending();
	180	spin_unlock_irq(&current->sighand->siglock);
	181
2fc10620 JD	182	current->state = TASK_INTERRUPTIBLE;
	183	schedule();
	184	set_thread_flag(TIF_RESTORE_SIGMASK);
	185	return -ERESTARTNOHAND;
1da177e4 LT	186	}
1da177e4 LT	187
1da177e4 LT	188	long sys_sigaltstack(const stack_t __user uss, stack_t __user uoss)
	189	{
	190	return(do_sigaltstack(uss, uoss, PT_REGS_SP(&current->thread.regs)));
	191	}