[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"

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)))

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;

	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;
	sigset_t set;
	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 |= restore_altstack(&sf->stack);
	
	if (err)
		goto segv;
		
	regs->pc = pc;
	regs->npc = npc;
	
	err |= __get_user(rwin_save, &sf->rwin_save);
	if (!err && rwin_save) {
		if (restore_rwin_state(rwin_save))
			goto segv;
	}

	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 ksignal *ksig, 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.  */
	sp = sigsp(sp, ksig) - 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 ksignal *ksig, struct pt_regs *regs,
		       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(ksig, regs, sigframe_size);

	if (invalid_frame_pointer(sf, sigframe_size)) {
		do_exit(SIGILL);
		return -EINVAL;
	}

	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)
		return err;
	
	/* 3. signal handler back-trampoline and parameters */
	regs->u_regs[UREG_FP] = (unsigned long) sf;
	regs->u_regs[UREG_I0] = ksig->sig;
	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) ksig->ka.sa.sa_handler;
	regs->npc = (regs->pc + 4);

	/* 5. return to kernel instructions */
	if (ksig->ka.ka_restorer)
		regs->u_regs[UREG_I7] = (unsigned long)ksig->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)
			return err;

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

static int setup_rt_frame(struct ksignal *ksig, struct pt_regs *regs,
			  sigset_t *oldset)
{
	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(ksig, regs, sigframe_size);
	if (invalid_frame_pointer(sf, sigframe_size)) {
		do_exit(SIGILL);
		return -EINVAL;
	}

	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 |= __save_altstack(&sf->stack, regs->u_regs[UREG_FP]);
	
	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, &ksig->info);

	if (err)
		return err;

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

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

	if (ksig->ka.ka_restorer)
		regs->u_regs[UREG_I7] = (unsigned long)ksig->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)
			return err;

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

static inline void
handle_signal(struct ksignal *ksig, struct pt_regs *regs)
{
	sigset_t *oldset = sigmask_to_save();
	int err;

	if (ksig->ka.sa.sa_flags & SA_SIGINFO)
		err = setup_rt_frame(ksig, regs, oldset);
	else
		err = setup_frame(ksig, regs, oldset);
	signal_setup_done(err, ksig, 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 ksignal ksig;
	int restart_syscall;
	bool has_handler;

	/* 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;

	has_handler = get_signal(&ksig);

	/* 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 (has_handler) {
		if (restart_syscall)
			syscall_restart(orig_i0, regs, &ksig.ka.sa);
		handle_signal(&ksig, regs);
	} else {
		if (restart_syscall) {
			switch (regs->u_regs[UREG_I0]) {
			case ERESTARTNOHAND:
	     		case ERESTARTSYS:
			case 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);
			case ERESTART_RESTARTBLOCK:
				regs->u_regs[UREG_G1] = __NR_restart_syscall;
				regs->pc -= 4;
				regs->npc -= 4;
				pt_regs_clear_syscall(regs);
			}
		}
		restore_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)
		do_signal(regs, orig_i0);
	if (thread_info_flags & _TIF_NOTIFY_RESUME) {
		clear_thread_flag(TIF_NOTIFY_RESUME);
		tracehook_notify_resume(regs);
	}
}

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	extern void fpsave(unsigned long fpregs, unsigned long fsr,
	33	void fpqueue, unsigned long fpqdepth);
	34	extern void fpload(unsigned long fpregs, unsigned long fsr);
	35
5526b7e4	36	struct signal_frame {
1da177e4	37	struct sparc_stackf ss;
4d7b92ad	38	__siginfo32_t info;
1da177e4 LT	39	__siginfo_fpu_t __user *fpu_save;
	40	unsigned long insns[2] __attribute__ ((aligned (8)));
	41	unsigned int extramask[_NSIG_WORDS - 1];
	42	unsigned int extra_size; /* Should be 0 */
5598473a DM	43	__siginfo_rwin_t __user *rwin_save;
5598473a DM	44	} __attribute__((aligned(8)));
1da177e4 LT	45
	46	struct rt_signal_frame {
	47	struct sparc_stackf ss;
	48	siginfo_t info;
	49	struct pt_regs regs;
	50	sigset_t mask;
	51	__siginfo_fpu_t __user *fpu_save;
	52	unsigned int insns[2];
	53	stack_t stack;
	54	unsigned int extra_size; /* Should be 0 */
5598473a DM	55	__siginfo_rwin_t __user *rwin_save;
5598473a DM	56	} __attribute__((aligned(8)));
1da177e4 LT	57
1da177e4 LT	58	/* Align macros */
5526b7e4	59	#define SF_ALIGNEDSZ (((sizeof(struct signal_frame) + 7) & (~7)))
1da177e4 LT	60	#define RT_ALIGNEDSZ (((sizeof(struct rt_signal_frame) + 7) & (~7)))
1da177e4 LT	61
5526b7e4	62	asmlinkage void do_sigreturn(struct pt_regs *regs)
1da177e4	63	{
5526b7e4	64	struct signal_frame __user *sf;
1da177e4 LT	65	unsigned long up_psr, pc, npc;
	66	sigset_t set;
	67	__siginfo_fpu_t __user *fpu_save;
5598473a	68	__siginfo_rwin_t __user *rwin_save;
1da177e4 LT	69	int err;
1da177e4 LT	70
5526b7e4 DM	71	/* Always make any pending restarted system calls return -EINTR */
	72	current_thread_info()->restart_block.fn = do_no_restart_syscall;
	73
	74	synchronize_user_stack();
	75
	76	sf = (struct signal_frame __user *) regs->u_regs[UREG_FP];
1da177e4 LT	77
	78	/* 1. Make sure we are not getting garbage from the user */
	79	if (!access_ok(VERIFY_READ, sf, sizeof(*sf)))
	80	goto segv_and_exit;
	81
	82	if (((unsigned long) sf) & 3)
	83	goto segv_and_exit;
	84
	85	err = __get_user(pc, &sf->info.si_regs.pc);
	86	err \|= __get_user(npc, &sf->info.si_regs.npc);
	87
	88	if ((pc \| npc) & 3)
	89	goto segv_and_exit;
	90
	91	/* 2. Restore the state */
	92	up_psr = regs->psr;
	93	err \|= __copy_from_user(regs, &sf->info.si_regs, sizeof(struct pt_regs));
	94
	95	/* User can only change condition codes and FPU enabling in %psr. */
	96	regs->psr = (up_psr & ~(PSR_ICC \| PSR_EF))
	97	\| (regs->psr & (PSR_ICC \| PSR_EF));
	98
28e61036 DM	99	/* Prevent syscall restart. */
	100	pt_regs_clear_syscall(regs);
	101
1da177e4	102	err \|= __get_user(fpu_save, &sf->fpu_save);
1da177e4 LT	103	if (fpu_save)
1da177e4 LT	104	err \|= restore_fpu_state(regs, fpu_save);
5598473a DM	105	err \|= __get_user(rwin_save, &sf->rwin_save);
	106	if (rwin_save)
	107	err \|= restore_rwin_state(rwin_save);
1da177e4 LT	108
	109	/* This is pretty much atomic, no amount locking would prevent
	110	* the races which exist anyways.
	111	*/
	112	err \|= __get_user(set.sig[0], &sf->info.si_mask);
	113	err \|= __copy_from_user(&set.sig[1], &sf->extramask,
	114	(_NSIG_WORDS-1) * sizeof(unsigned int));
	115
	116	if (err)
	117	goto segv_and_exit;
	118
faddf598	119	set_current_blocked(&set);
1da177e4 LT	120	return;
	121
	122	segv_and_exit:
	123	force_sig(SIGSEGV, current);
	124	}
	125
1da177e4 LT	126	asmlinkage void do_rt_sigreturn(struct pt_regs *regs)
	127	{
	128	struct rt_signal_frame __user *sf;
	129	unsigned int psr, pc, npc;
	130	__siginfo_fpu_t __user *fpu_save;
5598473a	131	__siginfo_rwin_t __user *rwin_save;
1da177e4	132	sigset_t set;
1da177e4 LT	133	int err;
	134
	135	synchronize_user_stack();
	136	sf = (struct rt_signal_frame __user *) regs->u_regs[UREG_FP];
	137	if (!access_ok(VERIFY_READ, sf, sizeof(*sf)) \|\|
	138	(((unsigned long) sf) & 0x03))
	139	goto segv;
	140
	141	err = __get_user(pc, &sf->regs.pc);
	142	err \|= __get_user(npc, &sf->regs.npc);
	143	err \|= ((pc \| npc) & 0x03);
	144
	145	err \|= __get_user(regs->y, &sf->regs.y);
	146	err \|= __get_user(psr, &sf->regs.psr);
	147
	148	err \|= __copy_from_user(&regs->u_regs[UREG_G1],
	149	&sf->regs.u_regs[UREG_G1], 15 * sizeof(u32));
	150
	151	regs->psr = (regs->psr & ~PSR_ICC) \| (psr & PSR_ICC);
	152
28e61036 DM	153	/* Prevent syscall restart. */
	154	pt_regs_clear_syscall(regs);
	155
1da177e4	156	err \|= __get_user(fpu_save, &sf->fpu_save);
5598473a	157	if (!err && fpu_save)
1da177e4 LT	158	err \|= restore_fpu_state(regs, fpu_save);
1da177e4 LT	159	err \|= __copy_from_user(&set, &sf->mask, sizeof(sigset_t));
99b06feb	160	err \|= restore_altstack(&sf->stack);
1da177e4 LT	161
	162	if (err)
	163	goto segv;
	164
	165	regs->pc = pc;
	166	regs->npc = npc;
	167
5598473a DM	168	err \|= __get_user(rwin_save, &sf->rwin_save);
	169	if (!err && rwin_save) {
	170	if (restore_rwin_state(rwin_save))
	171	goto segv;
	172	}
	173
faddf598	174	set_current_blocked(&set);
1da177e4 LT	175	return;
	176	segv:
	177	force_sig(SIGSEGV, current);
	178	}
	179
	180	/* Checks if the fp is valid */
	181	static inline int invalid_frame_pointer(void __user *fp, int fplen)
	182	{
3c23a766	183	if ((((unsigned long) fp) & 7) \|\| !__access_ok((unsigned long)fp, fplen))
1da177e4	184	return 1;
3c23a766	185
1da177e4 LT	186	return 0;
	187	}
	188
08f73957	189	static inline void __user get_sigframe(struct ksignal ksig, struct pt_regs *regs, unsigned long framesize)
1da177e4	190	{
dc5dc7e6	191	unsigned long sp = regs->u_regs[UREG_FP];
1da177e4	192
dc5dc7e6 DM	193	/*
	194	* If we are on the alternate signal stack and would overflow it, don't.
	195	* Return an always-bogus address instead so we will die with SIGSEGV.
	196	*/
	197	if (on_sig_stack(sp) && !likely(on_sig_stack(sp - framesize)))
	198	return (void __user *) -1L;
1da177e4 LT	199
1da177e4 LT	200	/* This is the X/Open sanctioned signal stack switching. */
08f73957	201	sp = sigsp(sp, ksig) - framesize;
f036d9f3	202
dc5dc7e6 DM	203	/* Always align the stack frame. This handles two cases. First,
	204	* sigaltstack need not be mindful of platform specific stack
	205	* alignment. Second, if we took this signal because the stack
	206	* is not aligned properly, we'd like to take the signal cleanly
	207	* and report that.
	208	*/
f036d9f3	209	sp &= ~15UL;
dc5dc7e6	210
f036d9f3	211	return (void __user *) sp;
1da177e4 LT	212	}
1da177e4 LT	213
08f73957 AV	214	static int setup_frame(struct ksignal ksig, struct pt_regs regs,
08f73957 AV	215	sigset_t *oldset)
1da177e4	216	{
5526b7e4	217	struct signal_frame __user *sf;
5598473a DM	218	int sigframe_size, err, wsaved;
5598473a DM	219	void __user *tail;
1da177e4 LT	220
	221	/* 1. Make sure everything is clean */
	222	synchronize_user_stack();
	223
5598473a DM	224	wsaved = current_thread_info()->w_saved;
	225
	226	sigframe_size = sizeof(*sf);
	227	if (used_math())
	228	sigframe_size += sizeof(__siginfo_fpu_t);
	229	if (wsaved)
	230	sigframe_size += sizeof(__siginfo_rwin_t);
1da177e4	231
5526b7e4	232	sf = (struct signal_frame __user *)
08f73957	233	get_sigframe(ksig, regs, sigframe_size);
1da177e4	234
08f73957 AV	235	if (invalid_frame_pointer(sf, sigframe_size)) {
	236	do_exit(SIGILL);
	237	return -EINVAL;
	238	}
1da177e4	239
5598473a	240	tail = sf + 1;
1da177e4 LT	241
	242	/* 2. Save the current process state */
	243	err = __copy_to_user(&sf->info.si_regs, regs, sizeof(struct pt_regs));
	244
	245	err \|= __put_user(0, &sf->extra_size);
	246
	247	if (used_math()) {
5598473a DM	248	__siginfo_fpu_t __user *fp = tail;
	249	tail += sizeof(*fp);
	250	err \|= save_fpu_state(regs, fp);
	251	err \|= __put_user(fp, &sf->fpu_save);
1da177e4 LT	252	} else {
	253	err \|= __put_user(0, &sf->fpu_save);
	254	}
5598473a DM	255	if (wsaved) {
	256	__siginfo_rwin_t __user *rwp = tail;
	257	tail += sizeof(*rwp);
	258	err \|= save_rwin_state(wsaved, rwp);
	259	err \|= __put_user(rwp, &sf->rwin_save);
	260	} else {
	261	err \|= __put_user(0, &sf->rwin_save);
	262	}
1da177e4 LT	263
	264	err \|= __put_user(oldset->sig[0], &sf->info.si_mask);
	265	err \|= __copy_to_user(sf->extramask, &oldset->sig[1],
	266	(_NSIG_WORDS - 1) * sizeof(unsigned int));
5598473a DM	267	if (!wsaved) {
	268	err \|= __copy_to_user(sf, (char *) regs->u_regs[UREG_FP],
	269	sizeof(struct reg_window32));
	270	} else {
	271	struct reg_window32 *rp;
	272
	273	rp = &current_thread_info()->reg_window[wsaved - 1];
	274	err \|= __copy_to_user(sf, rp, sizeof(struct reg_window32));
	275	}
1da177e4	276	if (err)
08f73957	277	return err;
1da177e4 LT	278
	279	/* 3. signal handler back-trampoline and parameters */
	280	regs->u_regs[UREG_FP] = (unsigned long) sf;
08f73957	281	regs->u_regs[UREG_I0] = ksig->sig;
1da177e4 LT	282	regs->u_regs[UREG_I1] = (unsigned long) &sf->info;
	283	regs->u_regs[UREG_I2] = (unsigned long) &sf->info;
	284
	285	/* 4. signal handler */
08f73957	286	regs->pc = (unsigned long) ksig->ka.sa.sa_handler;
1da177e4 LT	287	regs->npc = (regs->pc + 4);
	288
	289	/* 5. return to kernel instructions */
08f73957 AV	290	if (ksig->ka.ka_restorer)
08f73957 AV	291	regs->u_regs[UREG_I7] = (unsigned long)ksig->ka.ka_restorer;
1da177e4 LT	292	else {
	293	regs->u_regs[UREG_I7] = (unsigned long)(&(sf->insns[0]) - 2);
	294
	295	/* mov __NR_sigreturn, %g1 */
	296	err \|= __put_user(0x821020d8, &sf->insns[0]);
	297
	298	/* t 0x10 */
	299	err \|= __put_user(0x91d02010, &sf->insns[1]);
	300	if (err)
08f73957	301	return err;
1da177e4 LT	302
	303	/* Flush instruction space. */
	304	flush_sig_insns(current->mm, (unsigned long) &(sf->insns[0]));
	305	}
392c2180	306	return 0;
1da177e4 LT	307	}
1da177e4 LT	308
08f73957 AV	309	static int setup_rt_frame(struct ksignal ksig, struct pt_regs regs,
08f73957 AV	310	sigset_t *oldset)
1da177e4 LT	311	{
1da177e4 LT	312	struct rt_signal_frame __user *sf;
5598473a DM	313	int sigframe_size, wsaved;
5598473a DM	314	void __user *tail;
1da177e4 LT	315	unsigned int psr;
	316	int err;
	317
	318	synchronize_user_stack();
5598473a DM	319	wsaved = current_thread_info()->w_saved;
	320	sigframe_size = sizeof(*sf);
	321	if (used_math())
	322	sigframe_size += sizeof(__siginfo_fpu_t);
	323	if (wsaved)
	324	sigframe_size += sizeof(__siginfo_rwin_t);
1da177e4	325	sf = (struct rt_signal_frame __user *)
08f73957 AV	326	get_sigframe(ksig, regs, sigframe_size);
	327	if (invalid_frame_pointer(sf, sigframe_size)) {
	328	do_exit(SIGILL);
	329	return -EINVAL;
	330	}
1da177e4	331
5598473a	332	tail = sf + 1;
1da177e4 LT	333	err = __put_user(regs->pc, &sf->regs.pc);
	334	err \|= __put_user(regs->npc, &sf->regs.npc);
	335	err \|= __put_user(regs->y, &sf->regs.y);
	336	psr = regs->psr;
	337	if (used_math())
	338	psr \|= PSR_EF;
	339	err \|= __put_user(psr, &sf->regs.psr);
	340	err \|= __copy_to_user(&sf->regs.u_regs, regs->u_regs, sizeof(regs->u_regs));
	341	err \|= __put_user(0, &sf->extra_size);
	342
	343	if (psr & PSR_EF) {
5598473a DM	344	__siginfo_fpu_t *fp = tail;
	345	tail += sizeof(*fp);
	346	err \|= save_fpu_state(regs, fp);
	347	err \|= __put_user(fp, &sf->fpu_save);
1da177e4 LT	348	} else {
	349	err \|= __put_user(0, &sf->fpu_save);
	350	}
5598473a DM	351	if (wsaved) {
	352	__siginfo_rwin_t *rwp = tail;
	353	tail += sizeof(*rwp);
	354	err \|= save_rwin_state(wsaved, rwp);
	355	err \|= __put_user(rwp, &sf->rwin_save);
	356	} else {
	357	err \|= __put_user(0, &sf->rwin_save);
	358	}
1da177e4 LT	359	err \|= __copy_to_user(&sf->mask, &oldset->sig[0], sizeof(sigset_t));
	360
	361	/* Setup sigaltstack */
99b06feb	362	err \|= __save_altstack(&sf->stack, regs->u_regs[UREG_FP]);
1da177e4	363
5598473a DM	364	if (!wsaved) {
	365	err \|= __copy_to_user(sf, (char *) regs->u_regs[UREG_FP],
	366	sizeof(struct reg_window32));
	367	} else {
	368	struct reg_window32 *rp;
	369
	370	rp = &current_thread_info()->reg_window[wsaved - 1];
	371	err \|= __copy_to_user(sf, rp, sizeof(struct reg_window32));
	372	}
1da177e4	373
08f73957	374	err \|= copy_siginfo_to_user(&sf->info, &ksig->info);
1da177e4 LT	375
1da177e4 LT	376	if (err)
08f73957	377	return err;
1da177e4 LT	378
1da177e4 LT	379	regs->u_regs[UREG_FP] = (unsigned long) sf;
08f73957	380	regs->u_regs[UREG_I0] = ksig->sig;
1da177e4 LT	381	regs->u_regs[UREG_I1] = (unsigned long) &sf->info;
	382	regs->u_regs[UREG_I2] = (unsigned long) &sf->regs;
	383
08f73957	384	regs->pc = (unsigned long) ksig->ka.sa.sa_handler;
1da177e4 LT	385	regs->npc = (regs->pc + 4);
1da177e4 LT	386
08f73957 AV	387	if (ksig->ka.ka_restorer)
08f73957 AV	388	regs->u_regs[UREG_I7] = (unsigned long)ksig->ka.ka_restorer;
1da177e4 LT	389	else {
	390	regs->u_regs[UREG_I7] = (unsigned long)(&(sf->insns[0]) - 2);
	391
	392	/* mov __NR_sigreturn, %g1 */
	393	err \|= __put_user(0x821020d8, &sf->insns[0]);
	394
	395	/* t 0x10 */
	396	err \|= __put_user(0x91d02010, &sf->insns[1]);
	397	if (err)
08f73957	398	return err;
1da177e4 LT	399
	400	/* Flush instruction space. */
	401	flush_sig_insns(current->mm, (unsigned long) &(sf->insns[0]));
	402	}
392c2180	403	return 0;
1da177e4 LT	404	}
1da177e4 LT	405
a610d6e6	406	static inline void
08f73957	407	handle_signal(struct ksignal ksig, struct pt_regs regs)
1da177e4	408	{
b7f9a11a	409	sigset_t *oldset = sigmask_to_save();
392c2180 DM	410	int err;
392c2180 DM	411
08f73957 AV	412	if (ksig->ka.sa.sa_flags & SA_SIGINFO)
08f73957 AV	413	err = setup_rt_frame(ksig, regs, oldset);
ec98c6b9	414	else
08f73957 AV	415	err = setup_frame(ksig, regs, oldset);
08f73957 AV	416	signal_setup_done(err, ksig, 0);
1da177e4 LT	417	}
	418
	419	static inline void syscall_restart(unsigned long orig_i0, struct pt_regs *regs,
	420	struct sigaction *sa)
	421	{
	422	switch(regs->u_regs[UREG_I0]) {
	423	case ERESTART_RESTARTBLOCK:
	424	case ERESTARTNOHAND:
	425	no_system_call_restart:
	426	regs->u_regs[UREG_I0] = EINTR;
	427	regs->psr \|= PSR_C;
	428	break;
	429	case ERESTARTSYS:
	430	if (!(sa->sa_flags & SA_RESTART))
	431	goto no_system_call_restart;
	432	/* fallthrough */
	433	case ERESTARTNOINTR:
	434	regs->u_regs[UREG_I0] = orig_i0;
	435	regs->pc -= 4;
	436	regs->npc -= 4;
	437	}
	438	}
	439
	440	/* Note that 'init' is a special process: it doesn't get signals it doesn't
	441	* want to handle. Thus you cannot kill init even with a SIGKILL even by
	442	* mistake.
	443	*/
5a157d5b	444	static void do_signal(struct pt_regs *regs, unsigned long orig_i0)
1da177e4	445	{
08f73957	446	struct ksignal ksig;
28e61036	447	int restart_syscall;
08f73957	448	bool has_handler;
1da177e4	449
1d299bc7 DM	450	/* It's a lot of work and synchronization to add a new ptrace
	451	* register for GDB to save and restore in order to get
	452	* orig_i0 correct for syscall restarts when debugging.
	453	*
e88d2468 DM	454	* Although it should be the case that most of the global
	455	* registers are volatile across a system call, glibc already
	456	* depends upon that fact that we preserve them. So we can't
	457	* just use any global register to save away the orig_i0 value.
	458	*
	459	* In particular %g2, %g3, %g4, and %g5 are all assumed to be
	460	* preserved across a system call trap by various pieces of
	461	* code in glibc.
	462	*
	463	* %g7 is used as the "thread register". %g6 is not used in
	464	* any fixed manner. %g6 is used as a scratch register and
	465	* a compiler temporary, but it's value is never used across
	466	* a system call. Therefore %g6 is usable for orig_i0 storage.
1d299bc7	467	*/
28e61036	468	if (pt_regs_is_syscall(regs) && (regs->psr & PSR_C))
e88d2468	469	regs->u_regs[UREG_G6] = orig_i0;
1da177e4	470
08f73957	471	has_handler = get_signal(&ksig);
28e61036 DM	472
	473	/* If the debugger messes with the program counter, it clears
	474	* the software "in syscall" bit, directing us to not perform
	475	* a syscall restart.
	476	*/
1d299bc7 DM	477	restart_syscall = 0;
	478	if (pt_regs_is_syscall(regs) && (regs->psr & PSR_C)) {
	479	restart_syscall = 1;
e88d2468	480	orig_i0 = regs->u_regs[UREG_G6];
1d299bc7 DM	481	}
1d299bc7 DM	482
08f73957	483	if (has_handler) {
28e61036	484	if (restart_syscall)
08f73957 AV	485	syscall_restart(orig_i0, regs, &ksig.ka.sa);
	486	handle_signal(&ksig, regs);
	487	} else {
	488	if (restart_syscall) {
	489	switch (regs->u_regs[UREG_I0]) {
	490	case ERESTARTNOHAND:
	491	case ERESTARTSYS:
	492	case ERESTARTNOINTR:
	493	/* replay the system call when we are done */
	494	regs->u_regs[UREG_I0] = orig_i0;
	495	regs->pc -= 4;
	496	regs->npc -= 4;
	497	pt_regs_clear_syscall(regs);
	498	case ERESTART_RESTARTBLOCK:
	499	regs->u_regs[UREG_G1] = __NR_restart_syscall;
	500	regs->pc -= 4;
	501	regs->npc -= 4;
	502	pt_regs_clear_syscall(regs);
	503	}
	504	}
	505	restore_saved_sigmask();
1da177e4	506	}
1da177e4 LT	507	}
1da177e4 LT	508
5a157d5b DM	509	void do_notify_resume(struct pt_regs *regs, unsigned long orig_i0,
	510	unsigned long thread_info_flags)
	511	{
6fd84c08	512	if (thread_info_flags & _TIF_SIGPENDING)
5a157d5b DM	513	do_signal(regs, orig_i0);
	514	if (thread_info_flags & _TIF_NOTIFY_RESUME) {
	515	clear_thread_flag(TIF_NOTIFY_RESUME);
	516	tracehook_notify_resume(regs);
	517	}
	518	}
	519
1da177e4 LT	520	asmlinkage int
	521	do_sys_sigstack(struct sigstack __user ssptr, struct sigstack __user ossptr,
	522	unsigned long sp)
	523	{
	524	int ret = -EFAULT;
	525
	526	/* First see if old state is wanted. */
	527	if (ossptr) {
	528	if (put_user(current->sas_ss_sp + current->sas_ss_size,
	529	&ossptr->the_stack) \|\|
	530	__put_user(on_sig_stack(sp), &ossptr->cur_status))
	531	goto out;
	532	}
	533
	534	/* Now see if we want to update the new state. */
	535	if (ssptr) {
	536	char *ss_sp;
	537
	538	if (get_user(ss_sp, &ssptr->the_stack))
	539	goto out;
	540	/* If the current stack was set with sigaltstack, don't
	541	swap stacks while we are on it. */
	542	ret = -EPERM;
	543	if (current->sas_ss_sp && on_sig_stack(sp))
	544	goto out;
	545
	546	/* Since we don't know the extent of the stack, and we don't
	547	track onstack-ness, but rather calculate it, we must
	548	presume a size. Ho hum this interface is lossy. */
	549	current->sas_ss_sp = (unsigned long)ss_sp - SIGSTKSZ;
	550	current->sas_ss_size = SIGSTKSZ;
	551	}
	552	ret = 0;
	553	out:
	554	return ret;
	555	}