[deliverable/linux.git] / arch / sparc / kernel / signal_32.c

/*  linux/arch/sparc/kernel/signal.c
 *
 *  Copyright (C) 1991, 1992  Linus Torvalds
 *  Copyright (C) 1995 David S. Miller (davem@caip.rutgers.edu)
 *  Copyright (C) 1996 Miguel de Icaza (miguel@nuclecu.unam.mx)
 *  Copyright (C) 1997 Eddie C. Dost   (ecd@skynet.be)
 */

#include <linux/sched.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/mm.h>
#include <linux/tty.h>
#include <linux/smp.h>
#include <linux/binfmts.h>	/* do_coredum */
#include <linux/bitops.h>
#include <linux/tracehook.h>

#include <asm/uaccess.h>
#include <asm/ptrace.h>
#include <asm/pgalloc.h>
#include <asm/pgtable.h>
#include <asm/cacheflush.h>	/* flush_sig_insns */
#include <asm/switch_to.h>

#include "sigutil.h"

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

extern void fpsave(unsigned long *fpregs, unsigned long *fsr,
		   void *fpqueue, unsigned long *fpqdepth);
extern void fpload(unsigned long *fpregs, unsigned long *fsr);

struct signal_frame {
	struct sparc_stackf	ss;
	__siginfo32_t		info;
	__siginfo_fpu_t __user	*fpu_save;
	unsigned long		insns[2] __attribute__ ((aligned (8)));
	unsigned int		extramask[_NSIG_WORDS - 1];
	unsigned int		extra_size; /* Should be 0 */
	__siginfo_rwin_t __user	*rwin_save;
} __attribute__((aligned(8)));

struct rt_signal_frame {
	struct sparc_stackf	ss;
	siginfo_t		info;
	struct pt_regs		regs;
	sigset_t		mask;
	__siginfo_fpu_t __user	*fpu_save;
	unsigned int		insns[2];
	stack_t			stack;
	unsigned int		extra_size; /* Should be 0 */
	__siginfo_rwin_t __user	*rwin_save;
} __attribute__((aligned(8)));

/* Align macros */
#define SF_ALIGNEDSZ  (((sizeof(struct signal_frame) + 7) & (~7)))
#define RT_ALIGNEDSZ  (((sizeof(struct rt_signal_frame) + 7) & (~7)))

static int _sigpause_common(old_sigset_t set)
{
	sigset_t blocked;

	current->saved_sigmask = current->blocked;

	set &= _BLOCKABLE;
	siginitset(&blocked, set);
	set_current_blocked(&blocked);

	current->state = TASK_INTERRUPTIBLE;
	schedule();
	set_thread_flag(TIF_RESTORE_SIGMASK);

	return -ERESTARTNOHAND;
}

asmlinkage int sys_sigsuspend(old_sigset_t set)
{
	return _sigpause_common(set);
}

asmlinkage void do_sigreturn(struct pt_regs *regs)
{
	struct signal_frame __user *sf;
	unsigned long up_psr, pc, npc;
	sigset_t set;
	__siginfo_fpu_t __user *fpu_save;
	__siginfo_rwin_t __user *rwin_save;
	int err;

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

	synchronize_user_stack();

	sf = (struct signal_frame __user *) regs->u_regs[UREG_FP];

	/* 1. Make sure we are not getting garbage from the user */
	if (!access_ok(VERIFY_READ, sf, sizeof(*sf)))
		goto segv_and_exit;

	if (((unsigned long) sf) & 3)
		goto segv_and_exit;

	err = __get_user(pc,  &sf->info.si_regs.pc);
	err |= __get_user(npc, &sf->info.si_regs.npc);

	if ((pc | npc) & 3)
		goto segv_and_exit;

	/* 2. Restore the state */
	up_psr = regs->psr;
	err |= __copy_from_user(regs, &sf->info.si_regs, sizeof(struct pt_regs));

	/* User can only change condition codes and FPU enabling in %psr. */
	regs->psr = (up_psr & ~(PSR_ICC | PSR_EF))
		  | (regs->psr & (PSR_ICC | PSR_EF));

	/* Prevent syscall restart.  */
	pt_regs_clear_syscall(regs);

	err |= __get_user(fpu_save, &sf->fpu_save);
	if (fpu_save)
		err |= restore_fpu_state(regs, fpu_save);
	err |= __get_user(rwin_save, &sf->rwin_save);
	if (rwin_save)
		err |= restore_rwin_state(rwin_save);

	/* This is pretty much atomic, no amount locking would prevent
	 * the races which exist anyways.
	 */
	err |= __get_user(set.sig[0], &sf->info.si_mask);
	err |= __copy_from_user(&set.sig[1], &sf->extramask,
			        (_NSIG_WORDS-1) * sizeof(unsigned int));
			   
	if (err)
		goto segv_and_exit;

	sigdelsetmask(&set, ~_BLOCKABLE);
	set_current_blocked(&set);
	return;

segv_and_exit:
	force_sig(SIGSEGV, current);
}

asmlinkage void do_rt_sigreturn(struct pt_regs *regs)
{
	struct rt_signal_frame __user *sf;
	unsigned int psr, pc, npc;
	__siginfo_fpu_t __user *fpu_save;
	__siginfo_rwin_t __user *rwin_save;
	mm_segment_t old_fs;
	sigset_t set;
	stack_t st;
	int err;

	synchronize_user_stack();
	sf = (struct rt_signal_frame __user *) regs->u_regs[UREG_FP];
	if (!access_ok(VERIFY_READ, sf, sizeof(*sf)) ||
	    (((unsigned long) sf) & 0x03))
		goto segv;

	err = __get_user(pc, &sf->regs.pc);
	err |= __get_user(npc, &sf->regs.npc);
	err |= ((pc | npc) & 0x03);

	err |= __get_user(regs->y, &sf->regs.y);
	err |= __get_user(psr, &sf->regs.psr);

	err |= __copy_from_user(&regs->u_regs[UREG_G1],
				&sf->regs.u_regs[UREG_G1], 15 * sizeof(u32));

	regs->psr = (regs->psr & ~PSR_ICC) | (psr & PSR_ICC);

	/* Prevent syscall restart.  */
	pt_regs_clear_syscall(regs);

	err |= __get_user(fpu_save, &sf->fpu_save);
	if (!err && fpu_save)
		err |= restore_fpu_state(regs, fpu_save);
	err |= __copy_from_user(&set, &sf->mask, sizeof(sigset_t));
	
	err |= __copy_from_user(&st, &sf->stack, sizeof(stack_t));
	
	if (err)
		goto segv;
		
	regs->pc = pc;
	regs->npc = npc;
	
	/* It is more difficult to avoid calling this function than to
	 * call it and ignore errors.
	 */
	old_fs = get_fs();
	set_fs(KERNEL_DS);
	do_sigaltstack((const stack_t __user *) &st, NULL, (unsigned long)sf);
	set_fs(old_fs);

	err |= __get_user(rwin_save, &sf->rwin_save);
	if (!err && rwin_save) {
		if (restore_rwin_state(rwin_save))
			goto segv;
	}

	sigdelsetmask(&set, ~_BLOCKABLE);
	set_current_blocked(&set);
	return;
segv:
	force_sig(SIGSEGV, current);
}

/* Checks if the fp is valid */
static inline int invalid_frame_pointer(void __user *fp, int fplen)
{
	if ((((unsigned long) fp) & 7) || !__access_ok((unsigned long)fp, fplen))
		return 1;

	return 0;
}

static inline void __user *get_sigframe(struct sigaction *sa, struct pt_regs *regs, unsigned long framesize)
{
	unsigned long sp = regs->u_regs[UREG_FP];

	/*
	 * If we are on the alternate signal stack and would overflow it, don't.
	 * Return an always-bogus address instead so we will die with SIGSEGV.
	 */
	if (on_sig_stack(sp) && !likely(on_sig_stack(sp - framesize)))
		return (void __user *) -1L;

	/* This is the X/Open sanctioned signal stack switching.  */
	if (sa->sa_flags & SA_ONSTACK) {
		if (sas_ss_flags(sp) == 0)
			sp = current->sas_ss_sp + current->sas_ss_size;
	}

	sp -= framesize;

	/* Always align the stack frame.  This handles two cases.  First,
	 * sigaltstack need not be mindful of platform specific stack
	 * alignment.  Second, if we took this signal because the stack
	 * is not aligned properly, we'd like to take the signal cleanly
	 * and report that.
	 */
	sp &= ~15UL;

	return (void __user *) sp;
}

static int setup_frame(struct k_sigaction *ka, struct pt_regs *regs,
		       int signo, sigset_t *oldset)
{
	struct signal_frame __user *sf;
	int sigframe_size, err, wsaved;
	void __user *tail;

	/* 1. Make sure everything is clean */
	synchronize_user_stack();

	wsaved = current_thread_info()->w_saved;

	sigframe_size = sizeof(*sf);
	if (used_math())
		sigframe_size += sizeof(__siginfo_fpu_t);
	if (wsaved)
		sigframe_size += sizeof(__siginfo_rwin_t);

	sf = (struct signal_frame __user *)
		get_sigframe(&ka->sa, regs, sigframe_size);

	if (invalid_frame_pointer(sf, sigframe_size))
		goto sigill_and_return;

	tail = sf + 1;

	/* 2. Save the current process state */
	err = __copy_to_user(&sf->info.si_regs, regs, sizeof(struct pt_regs));
	
	err |= __put_user(0, &sf->extra_size);

	if (used_math()) {
		__siginfo_fpu_t __user *fp = tail;
		tail += sizeof(*fp);
		err |= save_fpu_state(regs, fp);
		err |= __put_user(fp, &sf->fpu_save);
	} else {
		err |= __put_user(0, &sf->fpu_save);
	}
	if (wsaved) {
		__siginfo_rwin_t __user *rwp = tail;
		tail += sizeof(*rwp);
		err |= save_rwin_state(wsaved, rwp);
		err |= __put_user(rwp, &sf->rwin_save);
	} else {
		err |= __put_user(0, &sf->rwin_save);
	}

	err |= __put_user(oldset->sig[0], &sf->info.si_mask);
	err |= __copy_to_user(sf->extramask, &oldset->sig[1],
			      (_NSIG_WORDS - 1) * sizeof(unsigned int));
	if (!wsaved) {
		err |= __copy_to_user(sf, (char *) regs->u_regs[UREG_FP],
				      sizeof(struct reg_window32));
	} else {
		struct reg_window32 *rp;

		rp = &current_thread_info()->reg_window[wsaved - 1];
		err |= __copy_to_user(sf, rp, sizeof(struct reg_window32));
	}
	if (err)
		goto sigsegv;
	
	/* 3. signal handler back-trampoline and parameters */
	regs->u_regs[UREG_FP] = (unsigned long) sf;
	regs->u_regs[UREG_I0] = signo;
	regs->u_regs[UREG_I1] = (unsigned long) &sf->info;
	regs->u_regs[UREG_I2] = (unsigned long) &sf->info;

	/* 4. signal handler */
	regs->pc = (unsigned long) ka->sa.sa_handler;
	regs->npc = (regs->pc + 4);

	/* 5. return to kernel instructions */
	if (ka->ka_restorer)
		regs->u_regs[UREG_I7] = (unsigned long)ka->ka_restorer;
	else {
		regs->u_regs[UREG_I7] = (unsigned long)(&(sf->insns[0]) - 2);

		/* mov __NR_sigreturn, %g1 */
		err |= __put_user(0x821020d8, &sf->insns[0]);

		/* t 0x10 */
		err |= __put_user(0x91d02010, &sf->insns[1]);
		if (err)
			goto sigsegv;

		/* Flush instruction space. */
		flush_sig_insns(current->mm, (unsigned long) &(sf->insns[0]));
	}
	return 0;

sigill_and_return:
	do_exit(SIGILL);
	return -EINVAL;

sigsegv:
	force_sigsegv(signo, current);
	return -EFAULT;
}

static int setup_rt_frame(struct k_sigaction *ka, struct pt_regs *regs,
			  int signo, sigset_t *oldset, siginfo_t *info)
{
	struct rt_signal_frame __user *sf;
	int sigframe_size, wsaved;
	void __user *tail;
	unsigned int psr;
	int err;

	synchronize_user_stack();
	wsaved = current_thread_info()->w_saved;
	sigframe_size = sizeof(*sf);
	if (used_math())
		sigframe_size += sizeof(__siginfo_fpu_t);
	if (wsaved)
		sigframe_size += sizeof(__siginfo_rwin_t);
	sf = (struct rt_signal_frame __user *)
		get_sigframe(&ka->sa, regs, sigframe_size);
	if (invalid_frame_pointer(sf, sigframe_size))
		goto sigill;

	tail = sf + 1;
	err  = __put_user(regs->pc, &sf->regs.pc);
	err |= __put_user(regs->npc, &sf->regs.npc);
	err |= __put_user(regs->y, &sf->regs.y);
	psr = regs->psr;
	if (used_math())
		psr |= PSR_EF;
	err |= __put_user(psr, &sf->regs.psr);
	err |= __copy_to_user(&sf->regs.u_regs, regs->u_regs, sizeof(regs->u_regs));
	err |= __put_user(0, &sf->extra_size);

	if (psr & PSR_EF) {
		__siginfo_fpu_t *fp = tail;
		tail += sizeof(*fp);
		err |= save_fpu_state(regs, fp);
		err |= __put_user(fp, &sf->fpu_save);
	} else {
		err |= __put_user(0, &sf->fpu_save);
	}
	if (wsaved) {
		__siginfo_rwin_t *rwp = tail;
		tail += sizeof(*rwp);
		err |= save_rwin_state(wsaved, rwp);
		err |= __put_user(rwp, &sf->rwin_save);
	} else {
		err |= __put_user(0, &sf->rwin_save);
	}
	err |= __copy_to_user(&sf->mask, &oldset->sig[0], sizeof(sigset_t));
	
	/* Setup sigaltstack */
	err |= __put_user(current->sas_ss_sp, &sf->stack.ss_sp);
	err |= __put_user(sas_ss_flags(regs->u_regs[UREG_FP]), &sf->stack.ss_flags);
	err |= __put_user(current->sas_ss_size, &sf->stack.ss_size);
	
	if (!wsaved) {
		err |= __copy_to_user(sf, (char *) regs->u_regs[UREG_FP],
				      sizeof(struct reg_window32));
	} else {
		struct reg_window32 *rp;

		rp = &current_thread_info()->reg_window[wsaved - 1];
		err |= __copy_to_user(sf, rp, sizeof(struct reg_window32));
	}

	err |= copy_siginfo_to_user(&sf->info, info);

	if (err)
		goto sigsegv;

	regs->u_regs[UREG_FP] = (unsigned long) sf;
	regs->u_regs[UREG_I0] = signo;
	regs->u_regs[UREG_I1] = (unsigned long) &sf->info;
	regs->u_regs[UREG_I2] = (unsigned long) &sf->regs;

	regs->pc = (unsigned long) ka->sa.sa_handler;
	regs->npc = (regs->pc + 4);

	if (ka->ka_restorer)
		regs->u_regs[UREG_I7] = (unsigned long)ka->ka_restorer;
	else {
		regs->u_regs[UREG_I7] = (unsigned long)(&(sf->insns[0]) - 2);

		/* mov __NR_sigreturn, %g1 */
		err |= __put_user(0x821020d8, &sf->insns[0]);

		/* t 0x10 */
		err |= __put_user(0x91d02010, &sf->insns[1]);
		if (err)
			goto sigsegv;

		/* Flush instruction space. */
		flush_sig_insns(current->mm, (unsigned long) &(sf->insns[0]));
	}
	return 0;

sigill:
	do_exit(SIGILL);
	return -EINVAL;

sigsegv:
	force_sigsegv(signo, current);
	return -EFAULT;
}

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

	if (ka->sa.sa_flags & SA_SIGINFO)
		err = setup_rt_frame(ka, regs, signr, oldset, info);
	else
		err = setup_frame(ka, regs, signr, oldset);

	if (err)
		return err;

	block_sigmask(ka, signr);
	tracehook_signal_handler(signr, info, ka, regs, 0);

	return 0;
}

static inline void syscall_restart(unsigned long orig_i0, struct pt_regs *regs,
				   struct sigaction *sa)
{
	switch(regs->u_regs[UREG_I0]) {
	case ERESTART_RESTARTBLOCK:
	case ERESTARTNOHAND:
	no_system_call_restart:
		regs->u_regs[UREG_I0] = EINTR;
		regs->psr |= PSR_C;
		break;
	case ERESTARTSYS:
		if (!(sa->sa_flags & SA_RESTART))
			goto no_system_call_restart;
		/* fallthrough */
	case ERESTARTNOINTR:
		regs->u_regs[UREG_I0] = orig_i0;
		regs->pc -= 4;
		regs->npc -= 4;
	}
}

/* Note that 'init' is a special process: it doesn't get signals it doesn't
 * want to handle. Thus you cannot kill init even with a SIGKILL even by
 * mistake.
 */
static void do_signal(struct pt_regs *regs, unsigned long orig_i0)
{
	struct k_sigaction ka;
	int restart_syscall;
	sigset_t *oldset;
	siginfo_t info;
	int signr;

	/* It's a lot of work and synchronization to add a new ptrace
	 * register for GDB to save and restore in order to get
	 * orig_i0 correct for syscall restarts when debugging.
	 *
	 * Although it should be the case that most of the global
	 * registers are volatile across a system call, glibc already
	 * depends upon that fact that we preserve them.  So we can't
	 * just use any global register to save away the orig_i0 value.
	 *
	 * In particular %g2, %g3, %g4, and %g5 are all assumed to be
	 * preserved across a system call trap by various pieces of
	 * code in glibc.
	 *
	 * %g7 is used as the "thread register".   %g6 is not used in
	 * any fixed manner.  %g6 is used as a scratch register and
	 * a compiler temporary, but it's value is never used across
	 * a system call.  Therefore %g6 is usable for orig_i0 storage.
	 */
	if (pt_regs_is_syscall(regs) && (regs->psr & PSR_C))
		regs->u_regs[UREG_G6] = orig_i0;

	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 the debugger messes with the program counter, it clears
	 * the software "in syscall" bit, directing us to not perform
	 * a syscall restart.
	 */
	restart_syscall = 0;
	if (pt_regs_is_syscall(regs) && (regs->psr & PSR_C)) {
		restart_syscall = 1;
		orig_i0 = regs->u_regs[UREG_G6];
	}


	if (signr > 0) {
		if (restart_syscall)
			syscall_restart(orig_i0, regs, &ka.sa);
		if (handle_signal(signr, &ka, &info, 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;
	}
	if (restart_syscall &&
	    (regs->u_regs[UREG_I0] == ERESTARTNOHAND ||
	     regs->u_regs[UREG_I0] == ERESTARTSYS ||
	     regs->u_regs[UREG_I0] == ERESTARTNOINTR)) {
		/* replay the system call when we are done */
		regs->u_regs[UREG_I0] = orig_i0;
		regs->pc -= 4;
		regs->npc -= 4;
		pt_regs_clear_syscall(regs);
	}
	if (restart_syscall &&
	    regs->u_regs[UREG_I0] == ERESTART_RESTARTBLOCK) {
		regs->u_regs[UREG_G1] = __NR_restart_syscall;
		regs->pc -= 4;
		regs->npc -= 4;
		pt_regs_clear_syscall(regs);
	}

	/* 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);
		set_current_blocked(&current->saved_sigmask);
	}
}

void do_notify_resume(struct pt_regs *regs, unsigned long orig_i0,
		      unsigned long thread_info_flags)
{
	if (thread_info_flags & (_TIF_SIGPENDING | _TIF_RESTORE_SIGMASK))
		do_signal(regs, orig_i0);
	if (thread_info_flags & _TIF_NOTIFY_RESUME) {
		clear_thread_flag(TIF_NOTIFY_RESUME);
		tracehook_notify_resume(regs);
		if (current->replacement_session_keyring)
			key_replace_session_keyring();
	}
}

asmlinkage int
do_sys_sigstack(struct sigstack __user *ssptr, struct sigstack __user *ossptr,
		unsigned long sp)
{
	int ret = -EFAULT;

	/* First see if old state is wanted. */
	if (ossptr) {
		if (put_user(current->sas_ss_sp + current->sas_ss_size,
			     &ossptr->the_stack) ||
		    __put_user(on_sig_stack(sp), &ossptr->cur_status))
			goto out;
	}

	/* Now see if we want to update the new state. */
	if (ssptr) {
		char *ss_sp;

		if (get_user(ss_sp, &ssptr->the_stack))
			goto out;
		/* If the current stack was set with sigaltstack, don't
		   swap stacks while we are on it.  */
		ret = -EPERM;
		if (current->sas_ss_sp && on_sig_stack(sp))
			goto out;

		/* Since we don't know the extent of the stack, and we don't
		   track onstack-ness, but rather calculate it, we must
		   presume a size.  Ho hum this interface is lossy.  */
		current->sas_ss_sp = (unsigned long)ss_sp - SIGSTKSZ;
		current->sas_ss_size = SIGSTKSZ;
	}
	ret = 0;
out:
	return ret;
}
Commit	Line	Data
5526b7e4	1	/* linux/arch/sparc/kernel/signal.c
1da177e4 LT	2	*
	3	* Copyright (C) 1991, 1992 Linus Torvalds
	4	* Copyright (C) 1995 David S. Miller (davem@caip.rutgers.edu)
	5	* Copyright (C) 1996 Miguel de Icaza (miguel@nuclecu.unam.mx)
	6	* Copyright (C) 1997 Eddie C. Dost (ecd@skynet.be)
	7	*/
	8
1da177e4 LT	9	#include <linux/sched.h>
	10	#include <linux/kernel.h>
	11	#include <linux/signal.h>
	12	#include <linux/errno.h>
	13	#include <linux/wait.h>
	14	#include <linux/ptrace.h>
	15	#include <linux/unistd.h>
	16	#include <linux/mm.h>
	17	#include <linux/tty.h>
	18	#include <linux/smp.h>
1da177e4 LT	19	#include <linux/binfmts.h> /* do_coredum */
1da177e4 LT	20	#include <linux/bitops.h>
5a157d5b	21	#include <linux/tracehook.h>
1da177e4 LT	22
	23	#include <asm/uaccess.h>
	24	#include <asm/ptrace.h>
1da177e4 LT	25	#include <asm/pgalloc.h>
	26	#include <asm/pgtable.h>
	27	#include <asm/cacheflush.h> /* flush_sig_insns */
d550bbd4	28	#include <asm/switch_to.h>
1da177e4	29
5598473a DM	30	#include "sigutil.h"
5598473a DM	31
1da177e4 LT	32	#define _BLOCKABLE (~(sigmask(SIGKILL) \| sigmask(SIGSTOP)))
	33
	34	extern void fpsave(unsigned long fpregs, unsigned long fsr,
	35	void fpqueue, unsigned long fpqdepth);
	36	extern void fpload(unsigned long fpregs, unsigned long fsr);
	37
5526b7e4	38	struct signal_frame {
1da177e4	39	struct sparc_stackf ss;
4d7b92ad	40	__siginfo32_t info;
1da177e4 LT	41	__siginfo_fpu_t __user *fpu_save;
	42	unsigned long insns[2] __attribute__ ((aligned (8)));
	43	unsigned int extramask[_NSIG_WORDS - 1];
	44	unsigned int extra_size; /* Should be 0 */
5598473a DM	45	__siginfo_rwin_t __user *rwin_save;
5598473a DM	46	} __attribute__((aligned(8)));
1da177e4 LT	47
	48	struct rt_signal_frame {
	49	struct sparc_stackf ss;
	50	siginfo_t info;
	51	struct pt_regs regs;
	52	sigset_t mask;
	53	__siginfo_fpu_t __user *fpu_save;
	54	unsigned int insns[2];
	55	stack_t stack;
	56	unsigned int extra_size; /* Should be 0 */
5598473a DM	57	__siginfo_rwin_t __user *rwin_save;
5598473a DM	58	} __attribute__((aligned(8)));
1da177e4 LT	59
1da177e4 LT	60	/* Align macros */
5526b7e4	61	#define SF_ALIGNEDSZ (((sizeof(struct signal_frame) + 7) & (~7)))
1da177e4 LT	62	#define RT_ALIGNEDSZ (((sizeof(struct rt_signal_frame) + 7) & (~7)))
1da177e4 LT	63
2d7d5f05	64	static int _sigpause_common(old_sigset_t set)
1da177e4	65	{
faddf598 MF	66	sigset_t blocked;
faddf598 MF	67
2d7d5f05	68	current->saved_sigmask = current->blocked;
faddf598 MF	69
	70	set &= _BLOCKABLE;
	71	siginitset(&blocked, set);
	72	set_current_blocked(&blocked);
1da177e4	73
2d7d5f05 DM	74	current->state = TASK_INTERRUPTIBLE;
	75	schedule();
	76	set_thread_flag(TIF_RESTORE_SIGMASK);
1da177e4	77
2d7d5f05	78	return -ERESTARTNOHAND;
1da177e4 LT	79	}
1da177e4 LT	80
2d7d5f05	81	asmlinkage int sys_sigsuspend(old_sigset_t set)
1da177e4	82	{
2d7d5f05	83	return _sigpause_common(set);
1da177e4 LT	84	}
1da177e4 LT	85
5526b7e4	86	asmlinkage void do_sigreturn(struct pt_regs *regs)
1da177e4	87	{
5526b7e4	88	struct signal_frame __user *sf;
1da177e4 LT	89	unsigned long up_psr, pc, npc;
	90	sigset_t set;
	91	__siginfo_fpu_t __user *fpu_save;
5598473a	92	__siginfo_rwin_t __user *rwin_save;
1da177e4 LT	93	int err;
1da177e4 LT	94
5526b7e4 DM	95	/* Always make any pending restarted system calls return -EINTR */
	96	current_thread_info()->restart_block.fn = do_no_restart_syscall;
	97
	98	synchronize_user_stack();
	99
	100	sf = (struct signal_frame __user *) regs->u_regs[UREG_FP];
1da177e4 LT	101
	102	/* 1. Make sure we are not getting garbage from the user */
	103	if (!access_ok(VERIFY_READ, sf, sizeof(*sf)))
	104	goto segv_and_exit;
	105
	106	if (((unsigned long) sf) & 3)
	107	goto segv_and_exit;
	108
	109	err = __get_user(pc, &sf->info.si_regs.pc);
	110	err \|= __get_user(npc, &sf->info.si_regs.npc);
	111
	112	if ((pc \| npc) & 3)
	113	goto segv_and_exit;
	114
	115	/* 2. Restore the state */
	116	up_psr = regs->psr;
	117	err \|= __copy_from_user(regs, &sf->info.si_regs, sizeof(struct pt_regs));
	118
	119	/* User can only change condition codes and FPU enabling in %psr. */
	120	regs->psr = (up_psr & ~(PSR_ICC \| PSR_EF))
	121	\| (regs->psr & (PSR_ICC \| PSR_EF));
	122
28e61036 DM	123	/* Prevent syscall restart. */
	124	pt_regs_clear_syscall(regs);
	125
1da177e4	126	err \|= __get_user(fpu_save, &sf->fpu_save);
1da177e4 LT	127	if (fpu_save)
1da177e4 LT	128	err \|= restore_fpu_state(regs, fpu_save);
5598473a DM	129	err \|= __get_user(rwin_save, &sf->rwin_save);
	130	if (rwin_save)
	131	err \|= restore_rwin_state(rwin_save);
1da177e4 LT	132
	133	/* This is pretty much atomic, no amount locking would prevent
	134	* the races which exist anyways.
	135	*/
	136	err \|= __get_user(set.sig[0], &sf->info.si_mask);
	137	err \|= __copy_from_user(&set.sig[1], &sf->extramask,
	138	(_NSIG_WORDS-1) * sizeof(unsigned int));
	139
	140	if (err)
	141	goto segv_and_exit;
	142
	143	sigdelsetmask(&set, ~_BLOCKABLE);
faddf598	144	set_current_blocked(&set);
1da177e4 LT	145	return;
	146
	147	segv_and_exit:
	148	force_sig(SIGSEGV, current);
	149	}
	150
1da177e4 LT	151	asmlinkage void do_rt_sigreturn(struct pt_regs *regs)
	152	{
	153	struct rt_signal_frame __user *sf;
	154	unsigned int psr, pc, npc;
	155	__siginfo_fpu_t __user *fpu_save;
5598473a	156	__siginfo_rwin_t __user *rwin_save;
1da177e4 LT	157	mm_segment_t old_fs;
	158	sigset_t set;
	159	stack_t st;
	160	int err;
	161
	162	synchronize_user_stack();
	163	sf = (struct rt_signal_frame __user *) regs->u_regs[UREG_FP];
	164	if (!access_ok(VERIFY_READ, sf, sizeof(*sf)) \|\|
	165	(((unsigned long) sf) & 0x03))
	166	goto segv;
	167
	168	err = __get_user(pc, &sf->regs.pc);
	169	err \|= __get_user(npc, &sf->regs.npc);
	170	err \|= ((pc \| npc) & 0x03);
	171
	172	err \|= __get_user(regs->y, &sf->regs.y);
	173	err \|= __get_user(psr, &sf->regs.psr);
	174
	175	err \|= __copy_from_user(&regs->u_regs[UREG_G1],
	176	&sf->regs.u_regs[UREG_G1], 15 * sizeof(u32));
	177
	178	regs->psr = (regs->psr & ~PSR_ICC) \| (psr & PSR_ICC);
	179
28e61036 DM	180	/* Prevent syscall restart. */
	181	pt_regs_clear_syscall(regs);
	182
1da177e4	183	err \|= __get_user(fpu_save, &sf->fpu_save);
5598473a	184	if (!err && fpu_save)
1da177e4 LT	185	err \|= restore_fpu_state(regs, fpu_save);
	186	err \|= __copy_from_user(&set, &sf->mask, sizeof(sigset_t));
	187
	188	err \|= __copy_from_user(&st, &sf->stack, sizeof(stack_t));
	189
	190	if (err)
	191	goto segv;
	192
	193	regs->pc = pc;
	194	regs->npc = npc;
	195
	196	/* It is more difficult to avoid calling this function than to
	197	* call it and ignore errors.
	198	*/
	199	old_fs = get_fs();
	200	set_fs(KERNEL_DS);
	201	do_sigaltstack((const stack_t __user *) &st, NULL, (unsigned long)sf);
	202	set_fs(old_fs);
	203
5598473a DM	204	err \|= __get_user(rwin_save, &sf->rwin_save);
	205	if (!err && rwin_save) {
	206	if (restore_rwin_state(rwin_save))
	207	goto segv;
	208	}
	209
1da177e4	210	sigdelsetmask(&set, ~_BLOCKABLE);
faddf598	211	set_current_blocked(&set);
1da177e4 LT	212	return;
	213	segv:
	214	force_sig(SIGSEGV, current);
	215	}
	216
	217	/* Checks if the fp is valid */
	218	static inline int invalid_frame_pointer(void __user *fp, int fplen)
	219	{
3c23a766	220	if ((((unsigned long) fp) & 7) \|\| !__access_ok((unsigned long)fp, fplen))
1da177e4	221	return 1;
3c23a766	222
1da177e4 LT	223	return 0;
	224	}
	225
	226	static inline void __user get_sigframe(struct sigaction sa, struct pt_regs *regs, unsigned long framesize)
	227	{
dc5dc7e6	228	unsigned long sp = regs->u_regs[UREG_FP];
1da177e4	229
dc5dc7e6 DM	230	/*
	231	* If we are on the alternate signal stack and would overflow it, don't.
	232	* Return an always-bogus address instead so we will die with SIGSEGV.
	233	*/
	234	if (on_sig_stack(sp) && !likely(on_sig_stack(sp - framesize)))
	235	return (void __user *) -1L;
1da177e4 LT	236
	237	/* This is the X/Open sanctioned signal stack switching. */
	238	if (sa->sa_flags & SA_ONSTACK) {
dc5dc7e6	239	if (sas_ss_flags(sp) == 0)
1da177e4 LT	240	sp = current->sas_ss_sp + current->sas_ss_size;
1da177e4 LT	241	}
dc5dc7e6	242
f036d9f3 DM	243	sp -= framesize;
f036d9f3 DM	244
dc5dc7e6 DM	245	/* Always align the stack frame. This handles two cases. First,
	246	* sigaltstack need not be mindful of platform specific stack
	247	* alignment. Second, if we took this signal because the stack
	248	* is not aligned properly, we'd like to take the signal cleanly
	249	* and report that.
	250	*/
f036d9f3	251	sp &= ~15UL;
dc5dc7e6	252
f036d9f3	253	return (void __user *) sp;
1da177e4 LT	254	}
1da177e4 LT	255
392c2180 DM	256	static int setup_frame(struct k_sigaction ka, struct pt_regs regs,
392c2180 DM	257	int signo, sigset_t *oldset)
1da177e4	258	{
5526b7e4	259	struct signal_frame __user *sf;
5598473a DM	260	int sigframe_size, err, wsaved;
5598473a DM	261	void __user *tail;
1da177e4 LT	262
	263	/* 1. Make sure everything is clean */
	264	synchronize_user_stack();
	265
5598473a DM	266	wsaved = current_thread_info()->w_saved;
	267
	268	sigframe_size = sizeof(*sf);
	269	if (used_math())
	270	sigframe_size += sizeof(__siginfo_fpu_t);
	271	if (wsaved)
	272	sigframe_size += sizeof(__siginfo_rwin_t);
1da177e4	273
5526b7e4	274	sf = (struct signal_frame __user *)
1da177e4 LT	275	get_sigframe(&ka->sa, regs, sigframe_size);
	276
	277	if (invalid_frame_pointer(sf, sigframe_size))
	278	goto sigill_and_return;
	279
5598473a	280	tail = sf + 1;
1da177e4 LT	281
	282	/* 2. Save the current process state */
	283	err = __copy_to_user(&sf->info.si_regs, regs, sizeof(struct pt_regs));
	284
	285	err \|= __put_user(0, &sf->extra_size);
	286
	287	if (used_math()) {
5598473a DM	288	__siginfo_fpu_t __user *fp = tail;
	289	tail += sizeof(*fp);
	290	err \|= save_fpu_state(regs, fp);
	291	err \|= __put_user(fp, &sf->fpu_save);
1da177e4 LT	292	} else {
	293	err \|= __put_user(0, &sf->fpu_save);
	294	}
5598473a DM	295	if (wsaved) {
	296	__siginfo_rwin_t __user *rwp = tail;
	297	tail += sizeof(*rwp);
	298	err \|= save_rwin_state(wsaved, rwp);
	299	err \|= __put_user(rwp, &sf->rwin_save);
	300	} else {
	301	err \|= __put_user(0, &sf->rwin_save);
	302	}
1da177e4 LT	303
	304	err \|= __put_user(oldset->sig[0], &sf->info.si_mask);
	305	err \|= __copy_to_user(sf->extramask, &oldset->sig[1],
	306	(_NSIG_WORDS - 1) * sizeof(unsigned int));
5598473a DM	307	if (!wsaved) {
	308	err \|= __copy_to_user(sf, (char *) regs->u_regs[UREG_FP],
	309	sizeof(struct reg_window32));
	310	} else {
	311	struct reg_window32 *rp;
	312
	313	rp = &current_thread_info()->reg_window[wsaved - 1];
	314	err \|= __copy_to_user(sf, rp, sizeof(struct reg_window32));
	315	}
1da177e4 LT	316	if (err)
	317	goto sigsegv;
	318
	319	/* 3. signal handler back-trampoline and parameters */
	320	regs->u_regs[UREG_FP] = (unsigned long) sf;
	321	regs->u_regs[UREG_I0] = signo;
	322	regs->u_regs[UREG_I1] = (unsigned long) &sf->info;
	323	regs->u_regs[UREG_I2] = (unsigned long) &sf->info;
	324
	325	/* 4. signal handler */
	326	regs->pc = (unsigned long) ka->sa.sa_handler;
	327	regs->npc = (regs->pc + 4);
	328
	329	/* 5. return to kernel instructions */
	330	if (ka->ka_restorer)
	331	regs->u_regs[UREG_I7] = (unsigned long)ka->ka_restorer;
	332	else {
	333	regs->u_regs[UREG_I7] = (unsigned long)(&(sf->insns[0]) - 2);
	334
	335	/* mov __NR_sigreturn, %g1 */
	336	err \|= __put_user(0x821020d8, &sf->insns[0]);
	337
	338	/* t 0x10 */
	339	err \|= __put_user(0x91d02010, &sf->insns[1]);
	340	if (err)
	341	goto sigsegv;
	342
	343	/* Flush instruction space. */
	344	flush_sig_insns(current->mm, (unsigned long) &(sf->insns[0]));
	345	}
392c2180	346	return 0;
1da177e4 LT	347
	348	sigill_and_return:
	349	do_exit(SIGILL);
392c2180 DM	350	return -EINVAL;
392c2180 DM	351
1da177e4 LT	352	sigsegv:
1da177e4 LT	353	force_sigsegv(signo, current);
392c2180	354	return -EFAULT;
1da177e4 LT	355	}
1da177e4 LT	356
392c2180 DM	357	static int setup_rt_frame(struct k_sigaction ka, struct pt_regs regs,
392c2180 DM	358	int signo, sigset_t oldset, siginfo_t info)
1da177e4 LT	359	{
1da177e4 LT	360	struct rt_signal_frame __user *sf;
5598473a DM	361	int sigframe_size, wsaved;
5598473a DM	362	void __user *tail;
1da177e4 LT	363	unsigned int psr;
	364	int err;
	365
	366	synchronize_user_stack();
5598473a DM	367	wsaved = current_thread_info()->w_saved;
	368	sigframe_size = sizeof(*sf);
	369	if (used_math())
	370	sigframe_size += sizeof(__siginfo_fpu_t);
	371	if (wsaved)
	372	sigframe_size += sizeof(__siginfo_rwin_t);
1da177e4 LT	373	sf = (struct rt_signal_frame __user *)
	374	get_sigframe(&ka->sa, regs, sigframe_size);
	375	if (invalid_frame_pointer(sf, sigframe_size))
	376	goto sigill;
1da177e4	377
5598473a	378	tail = sf + 1;
1da177e4 LT	379	err = __put_user(regs->pc, &sf->regs.pc);
	380	err \|= __put_user(regs->npc, &sf->regs.npc);
	381	err \|= __put_user(regs->y, &sf->regs.y);
	382	psr = regs->psr;
	383	if (used_math())
	384	psr \|= PSR_EF;
	385	err \|= __put_user(psr, &sf->regs.psr);
	386	err \|= __copy_to_user(&sf->regs.u_regs, regs->u_regs, sizeof(regs->u_regs));
	387	err \|= __put_user(0, &sf->extra_size);
	388
	389	if (psr & PSR_EF) {
5598473a DM	390	__siginfo_fpu_t *fp = tail;
	391	tail += sizeof(*fp);
	392	err \|= save_fpu_state(regs, fp);
	393	err \|= __put_user(fp, &sf->fpu_save);
1da177e4 LT	394	} else {
	395	err \|= __put_user(0, &sf->fpu_save);
	396	}
5598473a DM	397	if (wsaved) {
	398	__siginfo_rwin_t *rwp = tail;
	399	tail += sizeof(*rwp);
	400	err \|= save_rwin_state(wsaved, rwp);
	401	err \|= __put_user(rwp, &sf->rwin_save);
	402	} else {
	403	err \|= __put_user(0, &sf->rwin_save);
	404	}
1da177e4 LT	405	err \|= __copy_to_user(&sf->mask, &oldset->sig[0], sizeof(sigset_t));
	406
	407	/* Setup sigaltstack */
	408	err \|= __put_user(current->sas_ss_sp, &sf->stack.ss_sp);
	409	err \|= __put_user(sas_ss_flags(regs->u_regs[UREG_FP]), &sf->stack.ss_flags);
	410	err \|= __put_user(current->sas_ss_size, &sf->stack.ss_size);
	411
5598473a DM	412	if (!wsaved) {
	413	err \|= __copy_to_user(sf, (char *) regs->u_regs[UREG_FP],
	414	sizeof(struct reg_window32));
	415	} else {
	416	struct reg_window32 *rp;
	417
	418	rp = &current_thread_info()->reg_window[wsaved - 1];
	419	err \|= __copy_to_user(sf, rp, sizeof(struct reg_window32));
	420	}
1da177e4 LT	421
	422	err \|= copy_siginfo_to_user(&sf->info, info);
	423
	424	if (err)
	425	goto sigsegv;
	426
	427	regs->u_regs[UREG_FP] = (unsigned long) sf;
	428	regs->u_regs[UREG_I0] = signo;
	429	regs->u_regs[UREG_I1] = (unsigned long) &sf->info;
	430	regs->u_regs[UREG_I2] = (unsigned long) &sf->regs;
	431
	432	regs->pc = (unsigned long) ka->sa.sa_handler;
	433	regs->npc = (regs->pc + 4);
	434
	435	if (ka->ka_restorer)
	436	regs->u_regs[UREG_I7] = (unsigned long)ka->ka_restorer;
	437	else {
	438	regs->u_regs[UREG_I7] = (unsigned long)(&(sf->insns[0]) - 2);
	439
	440	/* mov __NR_sigreturn, %g1 */
	441	err \|= __put_user(0x821020d8, &sf->insns[0]);
	442
	443	/* t 0x10 */
	444	err \|= __put_user(0x91d02010, &sf->insns[1]);
	445	if (err)
	446	goto sigsegv;
	447
	448	/* Flush instruction space. */
	449	flush_sig_insns(current->mm, (unsigned long) &(sf->insns[0]));
	450	}
392c2180	451	return 0;
1da177e4 LT	452
	453	sigill:
	454	do_exit(SIGILL);
392c2180 DM	455	return -EINVAL;
392c2180 DM	456
1da177e4 LT	457	sigsegv:
1da177e4 LT	458	force_sigsegv(signo, current);
392c2180	459	return -EFAULT;
1da177e4 LT	460	}
1da177e4 LT	461
392c2180	462	static inline int
1da177e4	463	handle_signal(unsigned long signr, struct k_sigaction *ka,
ec98c6b9	464	siginfo_t info, sigset_t oldset, struct pt_regs *regs)
1da177e4	465	{
392c2180 DM	466	int err;
392c2180 DM	467
ec98c6b9	468	if (ka->sa.sa_flags & SA_SIGINFO)
392c2180	469	err = setup_rt_frame(ka, regs, signr, oldset, info);
ec98c6b9	470	else
392c2180 DM	471	err = setup_frame(ka, regs, signr, oldset);
	472
	473	if (err)
	474	return err;
ec98c6b9	475
ce24d8a1	476	block_sigmask(ka, signr);
392c2180 DM	477	tracehook_signal_handler(signr, info, ka, regs, 0);
	478
	479	return 0;
1da177e4 LT	480	}
	481
	482	static inline void syscall_restart(unsigned long orig_i0, struct pt_regs *regs,
	483	struct sigaction *sa)
	484	{
	485	switch(regs->u_regs[UREG_I0]) {
	486	case ERESTART_RESTARTBLOCK:
	487	case ERESTARTNOHAND:
	488	no_system_call_restart:
	489	regs->u_regs[UREG_I0] = EINTR;
	490	regs->psr \|= PSR_C;
	491	break;
	492	case ERESTARTSYS:
	493	if (!(sa->sa_flags & SA_RESTART))
	494	goto no_system_call_restart;
	495	/* fallthrough */
	496	case ERESTARTNOINTR:
	497	regs->u_regs[UREG_I0] = orig_i0;
	498	regs->pc -= 4;
	499	regs->npc -= 4;
	500	}
	501	}
	502
	503	/* Note that 'init' is a special process: it doesn't get signals it doesn't
	504	* want to handle. Thus you cannot kill init even with a SIGKILL even by
	505	* mistake.
	506	*/
5a157d5b	507	static void do_signal(struct pt_regs *regs, unsigned long orig_i0)
1da177e4	508	{
1da177e4	509	struct k_sigaction ka;
28e61036	510	int restart_syscall;
2d7d5f05	511	sigset_t *oldset;
28e61036 DM	512	siginfo_t info;
28e61036 DM	513	int signr;
1da177e4	514
1d299bc7 DM	515	/* It's a lot of work and synchronization to add a new ptrace
	516	* register for GDB to save and restore in order to get
	517	* orig_i0 correct for syscall restarts when debugging.
	518	*
e88d2468 DM	519	* Although it should be the case that most of the global
	520	* registers are volatile across a system call, glibc already
	521	* depends upon that fact that we preserve them. So we can't
	522	* just use any global register to save away the orig_i0 value.
	523	*
	524	* In particular %g2, %g3, %g4, and %g5 are all assumed to be
	525	* preserved across a system call trap by various pieces of
	526	* code in glibc.
	527	*
	528	* %g7 is used as the "thread register". %g6 is not used in
	529	* any fixed manner. %g6 is used as a scratch register and
	530	* a compiler temporary, but it's value is never used across
	531	* a system call. Therefore %g6 is usable for orig_i0 storage.
1d299bc7	532	*/
28e61036	533	if (pt_regs_is_syscall(regs) && (regs->psr & PSR_C))
e88d2468	534	regs->u_regs[UREG_G6] = orig_i0;
1da177e4	535
2d7d5f05 DM	536	if (test_thread_flag(TIF_RESTORE_SIGMASK))
	537	oldset = &current->saved_sigmask;
	538	else
1da177e4 LT	539	oldset = &current->blocked;
1da177e4 LT	540
28e61036 DM	541	signr = get_signal_to_deliver(&info, &ka, regs, NULL);
	542
	543	/* If the debugger messes with the program counter, it clears
	544	* the software "in syscall" bit, directing us to not perform
	545	* a syscall restart.
	546	*/
1d299bc7 DM	547	restart_syscall = 0;
	548	if (pt_regs_is_syscall(regs) && (regs->psr & PSR_C)) {
	549	restart_syscall = 1;
e88d2468	550	orig_i0 = regs->u_regs[UREG_G6];
1d299bc7 DM	551	}
1d299bc7 DM	552
28e61036	553
1da177e4	554	if (signr > 0) {
28e61036 DM	555	if (restart_syscall)
28e61036 DM	556	syscall_restart(orig_i0, regs, &ka.sa);
392c2180 DM	557	if (handle_signal(signr, &ka, &info, oldset, regs) == 0) {
	558	/* a signal was successfully delivered; the saved
	559	* sigmask will have been stored in the signal frame,
	560	* and will be restored by sigreturn, so we can simply
	561	* clear the TIF_RESTORE_SIGMASK flag.
	562	*/
	563	if (test_thread_flag(TIF_RESTORE_SIGMASK))
	564	clear_thread_flag(TIF_RESTORE_SIGMASK);
	565	}
2d7d5f05	566	return;
1da177e4	567	}
28e61036	568	if (restart_syscall &&
1da177e4 LT	569	(regs->u_regs[UREG_I0] == ERESTARTNOHAND \|\|
	570	regs->u_regs[UREG_I0] == ERESTARTSYS \|\|
	571	regs->u_regs[UREG_I0] == ERESTARTNOINTR)) {
	572	/* replay the system call when we are done */
28e61036	573	regs->u_regs[UREG_I0] = orig_i0;
1da177e4 LT	574	regs->pc -= 4;
1da177e4 LT	575	regs->npc -= 4;
c2785259	576	pt_regs_clear_syscall(regs);
1da177e4	577	}
28e61036	578	if (restart_syscall &&
1da177e4 LT	579	regs->u_regs[UREG_I0] == ERESTART_RESTARTBLOCK) {
	580	regs->u_regs[UREG_G1] = __NR_restart_syscall;
	581	regs->pc -= 4;
	582	regs->npc -= 4;
c2785259	583	pt_regs_clear_syscall(regs);
1da177e4	584	}
2d7d5f05 DM	585
	586	/* if there's no signal to deliver, we just put the saved sigmask
	587	* back
	588	*/
	589	if (test_thread_flag(TIF_RESTORE_SIGMASK)) {
	590	clear_thread_flag(TIF_RESTORE_SIGMASK);
27f20dca	591	set_current_blocked(&current->saved_sigmask);
2d7d5f05	592	}
1da177e4 LT	593	}
1da177e4 LT	594
5a157d5b DM	595	void do_notify_resume(struct pt_regs *regs, unsigned long orig_i0,
	596	unsigned long thread_info_flags)
	597	{
	598	if (thread_info_flags & (_TIF_SIGPENDING \| _TIF_RESTORE_SIGMASK))
	599	do_signal(regs, orig_i0);
	600	if (thread_info_flags & _TIF_NOTIFY_RESUME) {
	601	clear_thread_flag(TIF_NOTIFY_RESUME);
	602	tracehook_notify_resume(regs);
ee18d64c DH	603	if (current->replacement_session_keyring)
ee18d64c DH	604	key_replace_session_keyring();
5a157d5b DM	605	}
	606	}
	607
1da177e4 LT	608	asmlinkage int
	609	do_sys_sigstack(struct sigstack __user ssptr, struct sigstack __user ossptr,
	610	unsigned long sp)
	611	{
	612	int ret = -EFAULT;
	613
	614	/* First see if old state is wanted. */
	615	if (ossptr) {
	616	if (put_user(current->sas_ss_sp + current->sas_ss_size,
	617	&ossptr->the_stack) \|\|
	618	__put_user(on_sig_stack(sp), &ossptr->cur_status))
	619	goto out;
	620	}
	621
	622	/* Now see if we want to update the new state. */
	623	if (ssptr) {
	624	char *ss_sp;
	625
	626	if (get_user(ss_sp, &ssptr->the_stack))
	627	goto out;
	628	/* If the current stack was set with sigaltstack, don't
	629	swap stacks while we are on it. */
	630	ret = -EPERM;
	631	if (current->sas_ss_sp && on_sig_stack(sp))
	632	goto out;
	633
	634	/* Since we don't know the extent of the stack, and we don't
	635	track onstack-ness, but rather calculate it, we must
	636	presume a size. Ho hum this interface is lossy. */
	637	current->sas_ss_sp = (unsigned long)ss_sp - SIGSTKSZ;
	638	current->sas_ss_size = SIGSTKSZ;
	639	}
	640	ret = 0;
	641	out:
	642	return ret;
	643	}