irixsig.c

linux 内核源代码

/*
 * irixsig.c: WHEEE, IRIX signals!  YOW, am I compatible or what?!?!
 *
 * Copyright (C) 1996 David S. Miller ([e-mail])
 * Copyright (C) 1997 - 2000 Ralf Baechle ([e-mail])
 * Copyright (C) 2000 Silicon Graphics, Inc.
 */
#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/mm.h>
#include <linux/errno.h>
#include <linux/smp.h>
#include <linux/time.h>
#include <linux/ptrace.h>
#include <linux/resource.h>

#include <asm/ptrace.h>
#include <asm/uaccess.h>
#include <asm/unistd.h>

#undef DEBUG_SIG

#define _S(nr) (1<<((nr)-1))

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

#define _IRIX_NSIG		128
#define _IRIX_NSIG_BPW		BITS_PER_LONG
#define _IRIX_NSIG_WORDS	(_IRIX_NSIG / _IRIX_NSIG_BPW)

typedef struct {
	unsigned long sig[_IRIX_NSIG_WORDS];
} irix_sigset_t;

struct sigctx_irix5 {
	u32 rmask, cp0_status;
	u64 pc;
	u64 regs[32];
	u64 fpregs[32];
	u32 usedfp, fpcsr, fpeir, sstk_flags;
	u64 hi, lo;
	u64 cp0_cause, cp0_badvaddr, _unused0;
	irix_sigset_t sigset;
	u64 weird_fpu_thing;
	u64 _unused1[31];
};

#ifdef DEBUG_SIG
/* Debugging */
static inline void dump_irix5_sigctx(struct sigctx_irix5 *c)
{
	int i;

	printk("misc: rmask[%08lx] status[%08lx] pc[%08lx]\n",
	       (unsigned long) c->rmask,
	       (unsigned long) c->cp0_status,
	       (unsigned long) c->pc);
	printk("regs: ");
	for(i = 0; i < 16; i++)
		printk("[%d]<%08lx> ", i, (unsigned long) c->regs[i]);
	printk("\nregs: ");
	for(i = 16; i < 32; i++)
		printk("[%d]<%08lx> ", i, (unsigned long) c->regs[i]);
	printk("\nfpregs: ");
	for(i = 0; i < 16; i++)
		printk("[%d]<%08lx> ", i, (unsigned long) c->fpregs[i]);
	printk("\nfpregs: ");
	for(i = 16; i < 32; i++)
		printk("[%d]<%08lx> ", i, (unsigned long) c->fpregs[i]);
	printk("misc: usedfp[%d] fpcsr[%08lx] fpeir[%08lx] stk_flgs[%08lx]\n",
	       (int) c->usedfp, (unsigned long) c->fpcsr,
	       (unsigned long) c->fpeir, (unsigned long) c->sstk_flags);
	printk("misc: hi[%08lx] lo[%08lx] cause[%08lx] badvaddr[%08lx]\n",
	       (unsigned long) c->hi, (unsigned long) c->lo,
	       (unsigned long) c->cp0_cause, (unsigned long) c->cp0_badvaddr);
	printk("misc: sigset<0>[%08lx] sigset<1>[%08lx] sigset<2>[%08lx] "
	       "sigset<3>[%08lx]\n", (unsigned long) c->sigset.sig[0],
	       (unsigned long) c->sigset.sig[1],
	       (unsigned long) c->sigset.sig[2],
	       (unsigned long) c->sigset.sig[3]);
}
#endif

static int setup_irix_frame(struct k_sigaction *ka, struct pt_regs *regs,
			    int signr, sigset_t *oldmask)
{
	struct sigctx_irix5 __user *ctx;
	unsigned long sp;
	int error, i;

	sp = regs->regs[29];
	sp -= sizeof(struct sigctx_irix5);
	sp &= ~(0xf);
	ctx = (struct sigctx_irix5 __user *) sp;
	if (!access_ok(VERIFY_WRITE, ctx, sizeof(*ctx)))
		goto segv_and_exit;

	error = __put_user(0, &ctx->weird_fpu_thing);
	error |= __put_user(~(0x00000001), &ctx->rmask);
	error |= __put_user(0, &ctx->regs[0]);
	for(i = 1; i < 32; i++)
		error |= __put_user((u64) regs->regs[i], &ctx->regs[i]);

	error |= __put_user((u64) regs->hi, &ctx->hi);
	error |= __put_user((u64) regs->lo, &ctx->lo);
	error |= __put_user((u64) regs->cp0_epc, &ctx->pc);
	error |= __put_user(!!used_math(), &ctx->usedfp);
	error |= __put_user((u64) regs->cp0_cause, &ctx->cp0_cause);
	error |= __put_user((u64) regs->cp0_badvaddr, &ctx->cp0_badvaddr);

	error |= __put_user(0, &ctx->sstk_flags); /* XXX sigstack unimp... todo... */

	error |= __copy_to_user(&ctx->sigset, oldmask, sizeof(irix_sigset_t)) ? -EFAULT : 0;

	if (error)
		goto segv_and_exit;

#ifdef DEBUG_SIG
	dump_irix5_sigctx(ctx);
#endif

	regs->regs[4] = (unsigned long) signr;
	regs->regs[5] = 0; /* XXX sigcode XXX */
	regs->regs[6] = regs->regs[29] = sp;
	regs->regs[7] = (unsigned long) ka->sa.sa_handler;
	regs->regs[25] = regs->cp0_epc = (unsigned long) ka->sa_restorer;

	return 1;

segv_and_exit:
	force_sigsegv(signr, current);
	return 0;
}

static int inline
setup_irix_rt_frame(struct k_sigaction * ka, struct pt_regs *regs,
               int signr, sigset_t *oldmask, siginfo_t *info)
{
	printk("Aiee: setup_tr_frame wants to be written");
	do_exit(SIGSEGV);
}

static inline int handle_signal(unsigned long sig, siginfo_t *info,
	struct k_sigaction *ka, sigset_t *oldset, struct pt_regs * regs)
{
	int ret;

	switch(regs->regs[0]) {
	case ERESTARTNOHAND:
		regs->regs[2] = EINTR;
		break;
	case ERESTARTSYS:
		if(!(ka->sa.sa_flags & SA_RESTART)) {
			regs->regs[2] = EINTR;
			break;
		}
	/* fallthrough */
	case ERESTARTNOINTR:		/* Userland will reload $v0.  */
		regs->cp0_epc -= 8;
	}

	regs->regs[0] = 0;		/* Don't deal with this again.  */

	if (ka->sa.sa_flags & SA_SIGINFO)
		ret = setup_irix_rt_frame(ka, regs, sig, oldset, info);
	else
		ret = setup_irix_frame(ka, regs, sig, oldset);

	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, sig);
	recalc_sigpending();
	spin_unlock_irq(&current->sighand->siglock);

	return ret;
}

void do_irix_signal(struct pt_regs *regs)
{
	struct k_sigaction ka;
	siginfo_t info;
	int signr;
	sigset_t *oldset;

	/*
	 * We want the common case to go fast, which is why we may in certain
	 * cases get here from kernel mode. Just return without doing anything
	 * if so.
	 */
	if (!user_mode(regs))
		return;

	if (test_thread_flag(TIF_RESTORE_SIGMASK))
		oldset = &current->saved_sigmask;
	else
		oldset = &current->blocked;

	signr = get_signal_to_deliver(&info, &ka, regs, NULL);
	if (signr > 0) {
		/* Whee!  Actually deliver the signal.  */
		if (handle_signal(signr, &info, &ka, oldset, regs) == 0) {
			/* 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);
		}

		return;
	}

	/*
	 * Who's code doesn't conform to the restartable syscall convention
	 * dies here!!!  The li instruction, a single machine instruction,
	 * must directly be followed by the syscall instruction.
	 */
	if (regs->regs[0]) {
		if (regs->regs[2] == ERESTARTNOHAND ||
		    regs->regs[2] == ERESTARTSYS ||
		    regs->regs[2] == ERESTARTNOINTR) {
			regs->cp0_epc -= 8;
		}
		if (regs->regs[2] == ERESTART_RESTARTBLOCK) {
			regs->regs[2] = __NR_restart_syscall;
			regs->regs[7] = regs->regs[26];
			regs->cp0_epc -= 4;
		}
		regs->regs[0] = 0;	/* Don't deal with this again.  */
	}

	/*
	* If there's no signal to deliver, we just put the saved sigmask
	* back
	*/
	if (test_thread_flag(TIF_RESTORE_SIGMASK)) {
		clear_thread_flag(TIF_RESTORE_SIGMASK);
		sigprocmask(SIG_SETMASK, &current->saved_sigmask, NULL);
	}
}

asmlinkage void
irix_sigreturn(struct pt_regs *regs)
{
	struct sigctx_irix5 __user *context, *magic;
	unsigned long umask, mask;
	u64 *fregs;
	u32 usedfp;
	int error, sig, i, base = 0;
	sigset_t blocked;

	/* Always make any pending restarted system calls return -EINTR */
	current_thread_info()->restart_block.fn = do_no_restart_syscall;

	if (regs->regs[2] == 1000)
		base = 1;

	context = (struct sigctx_irix5 __user *) regs->regs[base + 4];
	magic = (struct sigctx_irix5 __user *) regs->regs[base + 5];
	sig = (int) regs->regs[base + 6];
#ifdef DEBUG_SIG
	printk("[%s:%d] IRIX sigreturn(scp[%p],ucp[%p],sig[%d])\n",
	       current->comm, current->pid, context, magic, sig);
#endif
	if (!context)
		context = magic;
	if (!access_ok(VERIFY_READ, context, sizeof(struct sigctx_irix5)))
		goto badframe;

#ifdef DEBUG_SIG
	dump_irix5_sigctx(context);
#endif

	error = __get_user(regs->cp0_epc, &context->pc);
	error |= __get_user(umask, &context->rmask);

	mask = 2;
	for (i = 1; i < 32; i++, mask <<= 1) {
		if (umask & mask)
			error |= __get_user(regs->regs[i], &context->regs[i]);
	}
	error |= __get_user(regs->hi, &context->hi);
	error |= __get_user(regs->lo, &context->lo);

	error |= __get_user(usedfp, &context->usedfp);
	if ((umask & 1) && usedfp) {
		fregs = (u64 *) &current->thread.fpu;

		for(i = 0; i < 32; i++)
			error |= __get_user(fregs[i], &context->fpregs[i]);
		error |= __get_user(current->thread.fpu.fcr31, &context->fpcsr);
	}

	/* XXX do sigstack crapola here... XXX */

	error |= __copy_from_user(&blocked, &context->sigset, sizeof(blocked)) ? -EFAULT : 0;

	if (error)
		goto badframe;

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

	/*
	 * Don't let your children do this ...
	 */
	__asm__ __volatile__(
		"move\t$29,%0\n\t"
		"j\tsyscall_exit"
		:/* no outputs */
		:"r" (&regs));
		/* Unreached */

badframe:
	force_sig(SIGSEGV, current);
}

struct sigact_irix5 {
	int flags;
	void (*handler)(int);
	u32 sigset[4];
	int _unused0[2];
};

#define SIG_SETMASK32	256	/* Goodie from SGI for BSD compatibility:
				   set only the low 32 bit of the sigset.  */

#ifdef DEBUG_SIG
static inline void dump_sigact_irix5(struct sigact_irix5 *p)
{
	printk("<f[%d] hndlr[%08lx] msk[%08lx]>", p->flags,
	       (unsigned long) p->handler,
	       (unsigned long) p->sigset[0]);
}
#endif

asmlinkage int
irix_sigaction(int sig, const struct sigaction __user *act,
	      struct sigaction __user *oact, void __user *trampoline)
{
	struct k_sigaction new_ka, old_ka;
	int ret;

#ifdef DEBUG_SIG
	printk(" (%d,%s,%s,%08lx) ", sig, (!new ? "0" : "NEW"),
	       (!old ? "0" : "OLD"), trampoline);
	if(new) {
		dump_sigact_irix5(new); printk(" ");
	}
#endif
	if (act) {
		sigset_t mask;
		int err;

		if (!access_ok(VERIFY_READ, act, sizeof(*act)))
			return -EFAULT;
		err = __get_user(new_ka.sa.sa_handler, &act->sa_handler);
		err |= __get_user(new_ka.sa.sa_flags, &act->sa_flags);

		err |= __copy_from_user(&mask, &act->sa_mask, sizeof(sigset_t)) ? -EFAULT : 0;
		if (err)
			return err;

		/*
		 * Hmmm... methinks IRIX libc always passes a valid trampoline
		 * value for all invocations of sigaction.  Will have to
		 * investigate.  POSIX POSIX, die die die...
		 */
		new_ka.sa_restorer = trampoline;
	}

/* XXX Implement SIG_SETMASK32 for IRIX compatibility */
	ret = do_sigaction(sig, act ? &new_ka : NULL, oact ? &old_ka : NULL);

	if (!ret && oact) {
		int err;

		if (!access_ok(VERIFY_WRITE, oact, sizeof(*oact)))
			return -EFAULT;

		err = __put_user(old_ka.sa.sa_handler, &oact->sa_handler);
		err |= __put_user(old_ka.sa.sa_flags, &oact->sa_flags);
		err |= __copy_to_user(&oact->sa_mask, &old_ka.sa.sa_mask,
		               sizeof(sigset_t)) ? -EFAULT : 0;
		if (err)
			return -EFAULT;
	}

	return ret;
}

asmlinkage int irix_sigpending(irix_sigset_t __user *set)
{
	return do_sigpending(set, sizeof(*set));
}

asmlinkage int irix_sigprocmask(int how, irix_sigset_t __user *new,
	irix_sigset_t __user *old)
{
	sigset_t oldbits, newbits;

	if (new) {
		if (!access_ok(VERIFY_READ, new, sizeof(*new)))
			return -EFAULT;
		if (__copy_from_user(&newbits, new, sizeof(unsigned long)*4))
			return -EFAULT;
		sigdelsetmask(&newbits, ~_BLOCKABLE);

		spin_lock_irq(&current->sighand->siglock);
		oldbits = current->blocked;

		switch(how) {
		case 1:
			sigorsets(&newbits, &oldbits, &newbits);
			break;

		case 2:
			sigandsets(&newbits, &oldbits, &newbits);
			break;

		case 3:
			break;

		case 256:
			siginitset(&newbits, newbits.sig[0]);
			break;

		default:
			spin_unlock_irq(&current->sighand->siglock);
			return -EINVAL;
		}
		recalc_sigpending();
		spin_unlock_irq(&current->sighand->siglock);
	}
	if (old)
		return copy_to_user(old, &current->blocked,
		                  sizeof(unsigned long)*4) ? -EFAULT : 0;

	return 0;