signal.c

microwindows移植到S3C44B0的源码

/*
 * arch/v850/kernel/signal.c -- Signal handling
 *
 *  Copyright (C) 2001  NEC Corporation
 *  Copyright (C) 2001  Miles Bader <[e-mail]>
 *  Copyright (C) 1999,2000  Niibe Yutaka & Kaz Kojima
 *  Copyright (C) 1991,1992  Linus Torvalds
 *
 * This file is subject to the terms and conditions of the GNU General
 * Public License.  See the file COPYING in the main directory of this
 * archive for more details.
 *
 * 1997-11-28  Modified for POSIX.1b signals by Richard Henderson
 *
 * This file was was derived from the sh version, arch/sh/kernel/signal.c
 */

#include <linux/sched.h>
#include <linux/mm.h>
#include <linux/smp.h>
#include <linux/smp_lock.h>
#include <linux/kernel.h>
#include <linux/signal.h>
#include <linux/errno.h>
#include <linux/wait.h>
#include <linux/ptrace.h>
#include <linux/unistd.h>
#include <linux/stddef.h>
#include <linux/personality.h>
#include <asm/ucontext.h>
#include <asm/uaccess.h>
#include <asm/pgtable.h>
#include <asm/pgalloc.h>

#define DEBUG_SIG 0

#define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP)))

asmlinkage int do_signal(struct pt_regs *regs, sigset_t *oldset);

int copy_siginfo_to_user(siginfo_t *to, siginfo_t *from)
{
	if (!access_ok (VERIFY_WRITE, to, sizeof(siginfo_t)))
		return -EFAULT;
	if (from->si_code < 0)
		return __copy_to_user(to, from, sizeof(siginfo_t));
	else {
		int err;

		/* If you change siginfo_t structure, please be sure
		   this code is fixed accordingly.
		   It should never copy any pad contained in the structure
		   to avoid security leaks, but must copy the generic
		   3 ints plus the relevant union member.  */
		err = __put_user(from->si_signo, &to->si_signo);
		err |= __put_user(from->si_errno, &to->si_errno);
		err |= __put_user((short)from->si_code, &to->si_code);
		/* First 32bits of unions are always present.  */
		err |= __put_user(from->si_pid, &to->si_pid);
		switch (from->si_code >> 16) {
		case __SI_FAULT >> 16:
			break;
		case __SI_CHLD >> 16:
			err |= __put_user(from->si_utime, &to->si_utime);
			err |= __put_user(from->si_stime, &to->si_stime);
			err |= __put_user(from->si_status, &to->si_status);
		default:
			err |= __put_user(from->si_uid, &to->si_uid);
			break;
		/* case __SI_RT: This is not generated by the kernel as of now.  */
		}
		return err;
	}
}

/*
 * Atomically swap in the new signal mask, and wait for a signal.
 */
asmlinkage int
sys_sigsuspend(old_sigset_t mask, struct pt_regs *regs)
{
	sigset_t saveset;

	mask &= _BLOCKABLE;
	spin_lock_irq(&current->sigmask_lock);
	saveset = current->blocked;
	siginitset(&current->blocked, mask);
	recalc_sigpending(current);
	spin_unlock_irq(&current->sigmask_lock);

	regs->gpr[GPR_RVAL] = -EINTR;
	while (1) {
		current->state = TASK_INTERRUPTIBLE;
		schedule();
		if (do_signal(regs, &saveset))
			return -EINTR;
	}
}

asmlinkage int
sys_rt_sigsuspend(sigset_t *unewset, size_t sigsetsize,
		  struct pt_regs *regs)
{
	sigset_t saveset, newset;

	/* XXX: Don't preclude handling different sized sigset_t's.  */
	if (sigsetsize != sizeof(sigset_t))
		return -EINVAL;

	if (copy_from_user(&newset, unewset, sizeof(newset)))
		return -EFAULT;
	sigdelsetmask(&newset, ~_BLOCKABLE);
	spin_lock_irq(&current->sigmask_lock);
	saveset = current->blocked;
	current->blocked = newset;
	recalc_sigpending(current);
	spin_unlock_irq(&current->sigmask_lock);

	regs->gpr[GPR_RVAL] = -EINTR;
	while (1) {
		current->state = TASK_INTERRUPTIBLE;
		schedule();
		if (do_signal(regs, &saveset))
			return -EINTR;
	}
}

asmlinkage int 
sys_sigaction(int sig, const struct old_sigaction *act,
	      struct old_sigaction *oact)
{
	struct k_sigaction new_ka, old_ka;
	int ret;

	if (act) {
		old_sigset_t mask;
		if (verify_area(VERIFY_READ, act, sizeof(*act)) ||
		    __get_user(new_ka.sa.sa_handler, &act->sa_handler) ||
		    __get_user(new_ka.sa.sa_restorer, &act->sa_restorer))
			return -EFAULT;
		__get_user(new_ka.sa.sa_flags, &act->sa_flags);
		__get_user(mask, &act->sa_mask);
		siginitset(&new_ka.sa.sa_mask, mask);
	}

	ret = do_sigaction(sig, act ? &new_ka : NULL, oact ? &old_ka : NULL);

	if (!ret && oact) {
		if (verify_area(VERIFY_WRITE, oact, sizeof(*oact)) ||
		    __put_user(old_ka.sa.sa_handler, &oact->sa_handler) ||
		    __put_user(old_ka.sa.sa_restorer, &oact->sa_restorer))
			return -EFAULT;
		__put_user(old_ka.sa.sa_flags, &oact->sa_flags);
		__put_user(old_ka.sa.sa_mask.sig[0], &oact->sa_mask);
	}

	return ret;
}

asmlinkage int
sys_sigaltstack(const stack_t *uss, stack_t *uoss,
		struct pt_regs *regs)
{
	return do_sigaltstack(uss, uoss, regs->gpr[GPR_SP]);
}


/*
 * Do a signal return; undo the signal stack.
 */

struct sigframe
{
	struct sigcontext sc;
	unsigned long extramask[_NSIG_WORDS-1];
	unsigned long tramp[2];	/* signal trampoline */
};

struct rt_sigframe
{
	struct siginfo *pinfo;
	void *puc;
	struct siginfo info;
	struct ucontext uc;
	unsigned long tramp[2];	/* signal trampoline */
};

static int
restore_sigcontext(struct pt_regs *regs, struct sigcontext *sc, int *rval_p)
{
	unsigned int err = 0;

#define COPY(x)		err |= __get_user(regs->x, &sc->regs.x)
	COPY(gpr[0]);	COPY(gpr[1]);	COPY(gpr[2]);	COPY(gpr[3]);
	COPY(gpr[4]);	COPY(gpr[5]);	COPY(gpr[6]);	COPY(gpr[7]);
	COPY(gpr[8]);	COPY(gpr[9]);	COPY(gpr[10]);	COPY(gpr[11]);
	COPY(gpr[12]);	COPY(gpr[13]);	COPY(gpr[14]);	COPY(gpr[15]);
	COPY(gpr[16]);	COPY(gpr[17]);	COPY(gpr[18]);	COPY(gpr[19]);
	COPY(gpr[20]);	COPY(gpr[21]);	COPY(gpr[22]);	COPY(gpr[23]);
	COPY(gpr[24]);	COPY(gpr[25]);	COPY(gpr[26]);	COPY(gpr[27]);
	COPY(gpr[28]);	COPY(gpr[29]);	COPY(gpr[30]);	COPY(gpr[31]);
	COPY(pc);	COPY(psw);
	COPY(ctpc);	COPY(ctpsw);	COPY(ctbp);
#undef COPY

	return err;
}

asmlinkage int sys_sigreturn(struct pt_regs *regs)
{
	struct sigframe *frame = (struct sigframe *)regs->gpr[GPR_SP];
	sigset_t set;
	int rval;

	if (verify_area(VERIFY_READ, frame, sizeof(*frame)))
		goto badframe;

	if (__get_user(set.sig[0], &frame->sc.oldmask)
	    || (_NSIG_WORDS > 1
		&& __copy_from_user(&set.sig[1], &frame->extramask,
				    sizeof(frame->extramask))))
		goto badframe;

	sigdelsetmask(&set, ~_BLOCKABLE);

	spin_lock_irq(&current->sigmask_lock);
	current->blocked = set;
	recalc_sigpending(current);
	spin_unlock_irq(&current->sigmask_lock);

	if (restore_sigcontext(regs, &frame->sc, &rval))
		goto badframe;
	return rval;

badframe:
	force_sig(SIGSEGV, current);
	return 0;
}

asmlinkage int sys_rt_sigreturn(struct pt_regs *regs)
{
	struct rt_sigframe *frame = (struct rt_sigframe *)regs->gpr[GPR_SP];
	sigset_t set;
	stack_t st;
	int rval;

	if (verify_area(VERIFY_READ, frame, sizeof(*frame)))
		goto badframe;

	if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set)))
		goto badframe;

	sigdelsetmask(&set, ~_BLOCKABLE);
	spin_lock_irq(&current->sigmask_lock);
	current->blocked = set;
	recalc_sigpending(current);
	spin_unlock_irq(&current->sigmask_lock);

	if (restore_sigcontext(regs, &frame->uc.uc_mcontext, &rval))
		goto badframe;

	if (__copy_from_user(&st, &frame->uc.uc_stack, sizeof(st)))
		goto badframe;
	/* It is more difficult to avoid calling this function than to
	   call it and ignore errors.  */
	do_sigaltstack(&st, NULL, regs->gpr[GPR_SP]);

	return rval;

badframe:
	force_sig(SIGSEGV, current);
	return 0;
}	

/*
 * Set up a signal frame.
 */

static int
setup_sigcontext(struct sigcontext *sc, struct pt_regs *regs,
		 unsigned long mask)
{
	int err = 0;

#define COPY(x)		err |= __put_user(regs->x, &sc->regs.x)
	COPY(gpr[0]);	COPY(gpr[1]);	COPY(gpr[2]);	COPY(gpr[3]);
	COPY(gpr[4]);	COPY(gpr[5]);	COPY(gpr[6]);	COPY(gpr[7]);
	COPY(gpr[8]);	COPY(gpr[9]);	COPY(gpr[10]);	COPY(gpr[11]);
	COPY(gpr[12]);	COPY(gpr[13]);	COPY(gpr[14]);	COPY(gpr[15]);
	COPY(gpr[16]);	COPY(gpr[17]);	COPY(gpr[18]);	COPY(gpr[19]);
	COPY(gpr[20]);	COPY(gpr[21]);	COPY(gpr[22]);	COPY(gpr[23]);
	COPY(gpr[24]);	COPY(gpr[25]);	COPY(gpr[26]);	COPY(gpr[27]);
	COPY(gpr[28]);	COPY(gpr[29]);	COPY(gpr[30]);	COPY(gpr[31]);
	COPY(pc);	COPY(psw);
	COPY(ctpc);	COPY(ctpsw);	COPY(ctbp);
#undef COPY

	err |= __put_user(mask, &sc->oldmask);

	return err;
}

/*
 * Determine which stack to use..
 */
static inline void *
get_sigframe(struct k_sigaction *ka, struct pt_regs *regs, size_t frame_size)
{
	/* Default to using normal stack */
	unsigned long sp = regs->gpr[GPR_SP];

	if ((ka->sa.sa_flags & SA_ONSTACK) != 0 && ! on_sig_stack(sp))
		sp = current->sas_ss_sp + current->sas_ss_size;

	return (void *)((sp - frame_size) & -8UL);
}

static void setup_frame(int sig, struct k_sigaction *ka,
			sigset_t *set, struct pt_regs *regs)
{
	struct sigframe *frame;
	int err = 0;