[linux-2.6-block.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)))

static int _sigpause_common(old_sigset_t set)
{
	sigset_t blocked;
	siginitset(&blocked, set);
	return sigsuspend(&blocked);
}

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;

	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;
	}

	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 void
handle_signal(unsigned long signr, struct k_sigaction *ka,
	      siginfo_t *info, struct pt_regs *regs)
{
	sigset_t *oldset = sigmask_to_save();
	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;

	signal_delivered(signr, info, ka, regs, 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;
	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;

	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);
		handle_signal(signr, &ka, &info, regs);
		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
	 */
	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
2d7d5f05	62	static int _sigpause_common(old_sigset_t set)
1da177e4	63	{
faddf598	64	sigset_t blocked;
faddf598	65	siginitset(&blocked, set);
68f3f16d	66	return sigsuspend(&blocked);
1da177e4 LT	67	}
1da177e4 LT	68
2d7d5f05	69	asmlinkage int sys_sigsuspend(old_sigset_t set)
1da177e4	70	{
2d7d5f05	71	return _sigpause_common(set);
1da177e4 LT	72	}
1da177e4 LT	73
5526b7e4	74	asmlinkage void do_sigreturn(struct pt_regs *regs)
1da177e4	75	{
5526b7e4	76	struct signal_frame __user *sf;
1da177e4 LT	77	unsigned long up_psr, pc, npc;
	78	sigset_t set;
	79	__siginfo_fpu_t __user *fpu_save;
5598473a	80	__siginfo_rwin_t __user *rwin_save;
1da177e4 LT	81	int err;
1da177e4 LT	82
5526b7e4 DM	83	/* Always make any pending restarted system calls return -EINTR */
	84	current_thread_info()->restart_block.fn = do_no_restart_syscall;
	85
	86	synchronize_user_stack();
	87
	88	sf = (struct signal_frame __user *) regs->u_regs[UREG_FP];
1da177e4 LT	89
	90	/* 1. Make sure we are not getting garbage from the user */
	91	if (!access_ok(VERIFY_READ, sf, sizeof(*sf)))
	92	goto segv_and_exit;
	93
	94	if (((unsigned long) sf) & 3)
	95	goto segv_and_exit;
	96
	97	err = __get_user(pc, &sf->info.si_regs.pc);
	98	err \|= __get_user(npc, &sf->info.si_regs.npc);
	99
	100	if ((pc \| npc) & 3)
	101	goto segv_and_exit;
	102
	103	/* 2. Restore the state */
	104	up_psr = regs->psr;
	105	err \|= __copy_from_user(regs, &sf->info.si_regs, sizeof(struct pt_regs));
	106
	107	/* User can only change condition codes and FPU enabling in %psr. */
	108	regs->psr = (up_psr & ~(PSR_ICC \| PSR_EF))
	109	\| (regs->psr & (PSR_ICC \| PSR_EF));
	110
28e61036 DM	111	/* Prevent syscall restart. */
	112	pt_regs_clear_syscall(regs);
	113
1da177e4	114	err \|= __get_user(fpu_save, &sf->fpu_save);
1da177e4 LT	115	if (fpu_save)
1da177e4 LT	116	err \|= restore_fpu_state(regs, fpu_save);
5598473a DM	117	err \|= __get_user(rwin_save, &sf->rwin_save);
	118	if (rwin_save)
	119	err \|= restore_rwin_state(rwin_save);
1da177e4 LT	120
	121	/* This is pretty much atomic, no amount locking would prevent
	122	* the races which exist anyways.
	123	*/
	124	err \|= __get_user(set.sig[0], &sf->info.si_mask);
	125	err \|= __copy_from_user(&set.sig[1], &sf->extramask,
	126	(_NSIG_WORDS-1) * sizeof(unsigned int));
	127
	128	if (err)
	129	goto segv_and_exit;
	130
faddf598	131	set_current_blocked(&set);
1da177e4 LT	132	return;
	133
	134	segv_and_exit:
	135	force_sig(SIGSEGV, current);
	136	}
	137
1da177e4 LT	138	asmlinkage void do_rt_sigreturn(struct pt_regs *regs)
	139	{
	140	struct rt_signal_frame __user *sf;
	141	unsigned int psr, pc, npc;
	142	__siginfo_fpu_t __user *fpu_save;
5598473a	143	__siginfo_rwin_t __user *rwin_save;
1da177e4 LT	144	mm_segment_t old_fs;
	145	sigset_t set;
	146	stack_t st;
	147	int err;
	148
	149	synchronize_user_stack();
	150	sf = (struct rt_signal_frame __user *) regs->u_regs[UREG_FP];
	151	if (!access_ok(VERIFY_READ, sf, sizeof(*sf)) \|\|
	152	(((unsigned long) sf) & 0x03))
	153	goto segv;
	154
	155	err = __get_user(pc, &sf->regs.pc);
	156	err \|= __get_user(npc, &sf->regs.npc);
	157	err \|= ((pc \| npc) & 0x03);
	158
	159	err \|= __get_user(regs->y, &sf->regs.y);
	160	err \|= __get_user(psr, &sf->regs.psr);
	161
	162	err \|= __copy_from_user(&regs->u_regs[UREG_G1],
	163	&sf->regs.u_regs[UREG_G1], 15 * sizeof(u32));
	164
	165	regs->psr = (regs->psr & ~PSR_ICC) \| (psr & PSR_ICC);
	166
28e61036 DM	167	/* Prevent syscall restart. */
	168	pt_regs_clear_syscall(regs);
	169
1da177e4	170	err \|= __get_user(fpu_save, &sf->fpu_save);
5598473a	171	if (!err && fpu_save)
1da177e4 LT	172	err \|= restore_fpu_state(regs, fpu_save);
	173	err \|= __copy_from_user(&set, &sf->mask, sizeof(sigset_t));
	174
	175	err \|= __copy_from_user(&st, &sf->stack, sizeof(stack_t));
	176
	177	if (err)
	178	goto segv;
	179
	180	regs->pc = pc;
	181	regs->npc = npc;
	182
	183	/* It is more difficult to avoid calling this function than to
	184	* call it and ignore errors.
	185	*/
	186	old_fs = get_fs();
	187	set_fs(KERNEL_DS);
	188	do_sigaltstack((const stack_t __user *) &st, NULL, (unsigned long)sf);
	189	set_fs(old_fs);
	190
5598473a DM	191	err \|= __get_user(rwin_save, &sf->rwin_save);
	192	if (!err && rwin_save) {
	193	if (restore_rwin_state(rwin_save))
	194	goto segv;
	195	}
	196
faddf598	197	set_current_blocked(&set);
1da177e4 LT	198	return;
	199	segv:
	200	force_sig(SIGSEGV, current);
	201	}
	202
	203	/* Checks if the fp is valid */
	204	static inline int invalid_frame_pointer(void __user *fp, int fplen)
	205	{
3c23a766	206	if ((((unsigned long) fp) & 7) \|\| !__access_ok((unsigned long)fp, fplen))
1da177e4	207	return 1;
3c23a766	208
1da177e4 LT	209	return 0;
	210	}
	211
	212	static inline void __user get_sigframe(struct sigaction sa, struct pt_regs *regs, unsigned long framesize)
	213	{
dc5dc7e6	214	unsigned long sp = regs->u_regs[UREG_FP];
1da177e4	215
dc5dc7e6 DM	216	/*
	217	* If we are on the alternate signal stack and would overflow it, don't.
	218	* Return an always-bogus address instead so we will die with SIGSEGV.
	219	*/
	220	if (on_sig_stack(sp) && !likely(on_sig_stack(sp - framesize)))
	221	return (void __user *) -1L;
1da177e4 LT	222
	223	/* This is the X/Open sanctioned signal stack switching. */
	224	if (sa->sa_flags & SA_ONSTACK) {
dc5dc7e6	225	if (sas_ss_flags(sp) == 0)
1da177e4 LT	226	sp = current->sas_ss_sp + current->sas_ss_size;
1da177e4 LT	227	}
dc5dc7e6	228
f036d9f3 DM	229	sp -= framesize;
f036d9f3 DM	230
dc5dc7e6 DM	231	/* Always align the stack frame. This handles two cases. First,
	232	* sigaltstack need not be mindful of platform specific stack
	233	* alignment. Second, if we took this signal because the stack
	234	* is not aligned properly, we'd like to take the signal cleanly
	235	* and report that.
	236	*/
f036d9f3	237	sp &= ~15UL;
dc5dc7e6	238
f036d9f3	239	return (void __user *) sp;
1da177e4 LT	240	}
1da177e4 LT	241
392c2180 DM	242	static int setup_frame(struct k_sigaction ka, struct pt_regs regs,
392c2180 DM	243	int signo, sigset_t *oldset)
1da177e4	244	{
5526b7e4	245	struct signal_frame __user *sf;
5598473a DM	246	int sigframe_size, err, wsaved;
5598473a DM	247	void __user *tail;
1da177e4 LT	248
	249	/* 1. Make sure everything is clean */
	250	synchronize_user_stack();
	251
5598473a DM	252	wsaved = current_thread_info()->w_saved;
	253
	254	sigframe_size = sizeof(*sf);
	255	if (used_math())
	256	sigframe_size += sizeof(__siginfo_fpu_t);
	257	if (wsaved)
	258	sigframe_size += sizeof(__siginfo_rwin_t);
1da177e4	259
5526b7e4	260	sf = (struct signal_frame __user *)
1da177e4 LT	261	get_sigframe(&ka->sa, regs, sigframe_size);
	262
	263	if (invalid_frame_pointer(sf, sigframe_size))
	264	goto sigill_and_return;
	265
5598473a	266	tail = sf + 1;
1da177e4 LT	267
	268	/* 2. Save the current process state */
	269	err = __copy_to_user(&sf->info.si_regs, regs, sizeof(struct pt_regs));
	270
	271	err \|= __put_user(0, &sf->extra_size);
	272
	273	if (used_math()) {
5598473a DM	274	__siginfo_fpu_t __user *fp = tail;
	275	tail += sizeof(*fp);
	276	err \|= save_fpu_state(regs, fp);
	277	err \|= __put_user(fp, &sf->fpu_save);
1da177e4 LT	278	} else {
	279	err \|= __put_user(0, &sf->fpu_save);
	280	}
5598473a DM	281	if (wsaved) {
	282	__siginfo_rwin_t __user *rwp = tail;
	283	tail += sizeof(*rwp);
	284	err \|= save_rwin_state(wsaved, rwp);
	285	err \|= __put_user(rwp, &sf->rwin_save);
	286	} else {
	287	err \|= __put_user(0, &sf->rwin_save);
	288	}
1da177e4 LT	289
	290	err \|= __put_user(oldset->sig[0], &sf->info.si_mask);
	291	err \|= __copy_to_user(sf->extramask, &oldset->sig[1],
	292	(_NSIG_WORDS - 1) * sizeof(unsigned int));
5598473a DM	293	if (!wsaved) {
	294	err \|= __copy_to_user(sf, (char *) regs->u_regs[UREG_FP],
	295	sizeof(struct reg_window32));
	296	} else {
	297	struct reg_window32 *rp;
	298
	299	rp = &current_thread_info()->reg_window[wsaved - 1];
	300	err \|= __copy_to_user(sf, rp, sizeof(struct reg_window32));
	301	}
1da177e4 LT	302	if (err)
	303	goto sigsegv;
	304
	305	/* 3. signal handler back-trampoline and parameters */
	306	regs->u_regs[UREG_FP] = (unsigned long) sf;
	307	regs->u_regs[UREG_I0] = signo;
	308	regs->u_regs[UREG_I1] = (unsigned long) &sf->info;
	309	regs->u_regs[UREG_I2] = (unsigned long) &sf->info;
	310
	311	/* 4. signal handler */
	312	regs->pc = (unsigned long) ka->sa.sa_handler;
	313	regs->npc = (regs->pc + 4);
	314
	315	/* 5. return to kernel instructions */
	316	if (ka->ka_restorer)
	317	regs->u_regs[UREG_I7] = (unsigned long)ka->ka_restorer;
	318	else {
	319	regs->u_regs[UREG_I7] = (unsigned long)(&(sf->insns[0]) - 2);
	320
	321	/* mov __NR_sigreturn, %g1 */
	322	err \|= __put_user(0x821020d8, &sf->insns[0]);
	323
	324	/* t 0x10 */
	325	err \|= __put_user(0x91d02010, &sf->insns[1]);
	326	if (err)
	327	goto sigsegv;
	328
	329	/* Flush instruction space. */
	330	flush_sig_insns(current->mm, (unsigned long) &(sf->insns[0]));
	331	}
392c2180	332	return 0;
1da177e4 LT	333
	334	sigill_and_return:
	335	do_exit(SIGILL);
392c2180 DM	336	return -EINVAL;
392c2180 DM	337
1da177e4 LT	338	sigsegv:
1da177e4 LT	339	force_sigsegv(signo, current);
392c2180	340	return -EFAULT;
1da177e4 LT	341	}
1da177e4 LT	342
392c2180 DM	343	static int setup_rt_frame(struct k_sigaction ka, struct pt_regs regs,
392c2180 DM	344	int signo, sigset_t oldset, siginfo_t info)
1da177e4 LT	345	{
1da177e4 LT	346	struct rt_signal_frame __user *sf;
5598473a DM	347	int sigframe_size, wsaved;
5598473a DM	348	void __user *tail;
1da177e4 LT	349	unsigned int psr;
	350	int err;
	351
	352	synchronize_user_stack();
5598473a DM	353	wsaved = current_thread_info()->w_saved;
	354	sigframe_size = sizeof(*sf);
	355	if (used_math())
	356	sigframe_size += sizeof(__siginfo_fpu_t);
	357	if (wsaved)
	358	sigframe_size += sizeof(__siginfo_rwin_t);
1da177e4 LT	359	sf = (struct rt_signal_frame __user *)
	360	get_sigframe(&ka->sa, regs, sigframe_size);
	361	if (invalid_frame_pointer(sf, sigframe_size))
	362	goto sigill;
1da177e4	363
5598473a	364	tail = sf + 1;
1da177e4 LT	365	err = __put_user(regs->pc, &sf->regs.pc);
	366	err \|= __put_user(regs->npc, &sf->regs.npc);
	367	err \|= __put_user(regs->y, &sf->regs.y);
	368	psr = regs->psr;
	369	if (used_math())
	370	psr \|= PSR_EF;
	371	err \|= __put_user(psr, &sf->regs.psr);
	372	err \|= __copy_to_user(&sf->regs.u_regs, regs->u_regs, sizeof(regs->u_regs));
	373	err \|= __put_user(0, &sf->extra_size);
	374
	375	if (psr & PSR_EF) {
5598473a DM	376	__siginfo_fpu_t *fp = tail;
	377	tail += sizeof(*fp);
	378	err \|= save_fpu_state(regs, fp);
	379	err \|= __put_user(fp, &sf->fpu_save);
1da177e4 LT	380	} else {
	381	err \|= __put_user(0, &sf->fpu_save);
	382	}
5598473a DM	383	if (wsaved) {
	384	__siginfo_rwin_t *rwp = tail;
	385	tail += sizeof(*rwp);
	386	err \|= save_rwin_state(wsaved, rwp);
	387	err \|= __put_user(rwp, &sf->rwin_save);
	388	} else {
	389	err \|= __put_user(0, &sf->rwin_save);
	390	}
1da177e4 LT	391	err \|= __copy_to_user(&sf->mask, &oldset->sig[0], sizeof(sigset_t));
	392
	393	/* Setup sigaltstack */
	394	err \|= __put_user(current->sas_ss_sp, &sf->stack.ss_sp);
	395	err \|= __put_user(sas_ss_flags(regs->u_regs[UREG_FP]), &sf->stack.ss_flags);
	396	err \|= __put_user(current->sas_ss_size, &sf->stack.ss_size);
	397
5598473a DM	398	if (!wsaved) {
	399	err \|= __copy_to_user(sf, (char *) regs->u_regs[UREG_FP],
	400	sizeof(struct reg_window32));
	401	} else {
	402	struct reg_window32 *rp;
	403
	404	rp = &current_thread_info()->reg_window[wsaved - 1];
	405	err \|= __copy_to_user(sf, rp, sizeof(struct reg_window32));
	406	}
1da177e4 LT	407
	408	err \|= copy_siginfo_to_user(&sf->info, info);
	409
	410	if (err)
	411	goto sigsegv;
	412
	413	regs->u_regs[UREG_FP] = (unsigned long) sf;
	414	regs->u_regs[UREG_I0] = signo;
	415	regs->u_regs[UREG_I1] = (unsigned long) &sf->info;
	416	regs->u_regs[UREG_I2] = (unsigned long) &sf->regs;
	417
	418	regs->pc = (unsigned long) ka->sa.sa_handler;
	419	regs->npc = (regs->pc + 4);
	420
	421	if (ka->ka_restorer)
	422	regs->u_regs[UREG_I7] = (unsigned long)ka->ka_restorer;
	423	else {
	424	regs->u_regs[UREG_I7] = (unsigned long)(&(sf->insns[0]) - 2);
	425
	426	/* mov __NR_sigreturn, %g1 */
	427	err \|= __put_user(0x821020d8, &sf->insns[0]);
	428
	429	/* t 0x10 */
	430	err \|= __put_user(0x91d02010, &sf->insns[1]);
	431	if (err)
	432	goto sigsegv;
	433
	434	/* Flush instruction space. */
	435	flush_sig_insns(current->mm, (unsigned long) &(sf->insns[0]));
	436	}
392c2180	437	return 0;
1da177e4 LT	438
	439	sigill:
	440	do_exit(SIGILL);
392c2180 DM	441	return -EINVAL;
392c2180 DM	442
1da177e4 LT	443	sigsegv:
1da177e4 LT	444	force_sigsegv(signo, current);
392c2180	445	return -EFAULT;
1da177e4 LT	446	}
1da177e4 LT	447
a610d6e6	448	static inline void
1da177e4	449	handle_signal(unsigned long signr, struct k_sigaction *ka,
b7f9a11a	450	siginfo_t info, struct pt_regs regs)
1da177e4	451	{
b7f9a11a	452	sigset_t *oldset = sigmask_to_save();
392c2180 DM	453	int err;
392c2180 DM	454
ec98c6b9	455	if (ka->sa.sa_flags & SA_SIGINFO)
392c2180	456	err = setup_rt_frame(ka, regs, signr, oldset, info);
ec98c6b9	457	else
392c2180 DM	458	err = setup_frame(ka, regs, signr, oldset);
	459
	460	if (err)
a610d6e6	461	return;
ec98c6b9	462
efee984c	463	signal_delivered(signr, info, ka, regs, 0);
1da177e4 LT	464	}
	465
	466	static inline void syscall_restart(unsigned long orig_i0, struct pt_regs *regs,
	467	struct sigaction *sa)
	468	{
	469	switch(regs->u_regs[UREG_I0]) {
	470	case ERESTART_RESTARTBLOCK:
	471	case ERESTARTNOHAND:
	472	no_system_call_restart:
	473	regs->u_regs[UREG_I0] = EINTR;
	474	regs->psr \|= PSR_C;
	475	break;
	476	case ERESTARTSYS:
	477	if (!(sa->sa_flags & SA_RESTART))
	478	goto no_system_call_restart;
	479	/* fallthrough */
	480	case ERESTARTNOINTR:
	481	regs->u_regs[UREG_I0] = orig_i0;
	482	regs->pc -= 4;
	483	regs->npc -= 4;
	484	}
	485	}
	486
	487	/* Note that 'init' is a special process: it doesn't get signals it doesn't
	488	* want to handle. Thus you cannot kill init even with a SIGKILL even by
	489	* mistake.
	490	*/
5a157d5b	491	static void do_signal(struct pt_regs *regs, unsigned long orig_i0)
1da177e4	492	{
1da177e4	493	struct k_sigaction ka;
28e61036	494	int restart_syscall;
28e61036 DM	495	siginfo_t info;
28e61036 DM	496	int signr;
1da177e4	497
1d299bc7 DM	498	/* It's a lot of work and synchronization to add a new ptrace
	499	* register for GDB to save and restore in order to get
	500	* orig_i0 correct for syscall restarts when debugging.
	501	*
e88d2468 DM	502	* Although it should be the case that most of the global
	503	* registers are volatile across a system call, glibc already
	504	* depends upon that fact that we preserve them. So we can't
	505	* just use any global register to save away the orig_i0 value.
	506	*
	507	* In particular %g2, %g3, %g4, and %g5 are all assumed to be
	508	* preserved across a system call trap by various pieces of
	509	* code in glibc.
	510	*
	511	* %g7 is used as the "thread register". %g6 is not used in
	512	* any fixed manner. %g6 is used as a scratch register and
	513	* a compiler temporary, but it's value is never used across
	514	* a system call. Therefore %g6 is usable for orig_i0 storage.
1d299bc7	515	*/
28e61036	516	if (pt_regs_is_syscall(regs) && (regs->psr & PSR_C))
e88d2468	517	regs->u_regs[UREG_G6] = orig_i0;
1da177e4	518
28e61036 DM	519	signr = get_signal_to_deliver(&info, &ka, regs, NULL);
	520
	521	/* If the debugger messes with the program counter, it clears
	522	* the software "in syscall" bit, directing us to not perform
	523	* a syscall restart.
	524	*/
1d299bc7 DM	525	restart_syscall = 0;
	526	if (pt_regs_is_syscall(regs) && (regs->psr & PSR_C)) {
	527	restart_syscall = 1;
e88d2468	528	orig_i0 = regs->u_regs[UREG_G6];
1d299bc7 DM	529	}
1d299bc7 DM	530
28e61036	531
1da177e4	532	if (signr > 0) {
28e61036 DM	533	if (restart_syscall)
28e61036 DM	534	syscall_restart(orig_i0, regs, &ka.sa);
a610d6e6	535	handle_signal(signr, &ka, &info, regs);
2d7d5f05	536	return;
1da177e4	537	}
28e61036	538	if (restart_syscall &&
1da177e4 LT	539	(regs->u_regs[UREG_I0] == ERESTARTNOHAND \|\|
	540	regs->u_regs[UREG_I0] == ERESTARTSYS \|\|
	541	regs->u_regs[UREG_I0] == ERESTARTNOINTR)) {
	542	/* replay the system call when we are done */
28e61036	543	regs->u_regs[UREG_I0] = orig_i0;
1da177e4 LT	544	regs->pc -= 4;
1da177e4 LT	545	regs->npc -= 4;
c2785259	546	pt_regs_clear_syscall(regs);
1da177e4	547	}
28e61036	548	if (restart_syscall &&
1da177e4 LT	549	regs->u_regs[UREG_I0] == ERESTART_RESTARTBLOCK) {
	550	regs->u_regs[UREG_G1] = __NR_restart_syscall;
	551	regs->pc -= 4;
	552	regs->npc -= 4;
c2785259	553	pt_regs_clear_syscall(regs);
1da177e4	554	}
2d7d5f05 DM	555
	556	/* if there's no signal to deliver, we just put the saved sigmask
	557	* back
	558	*/
51a7b448	559	restore_saved_sigmask();
1da177e4 LT	560	}
1da177e4 LT	561
5a157d5b DM	562	void do_notify_resume(struct pt_regs *regs, unsigned long orig_i0,
	563	unsigned long thread_info_flags)
	564	{
6fd84c08	565	if (thread_info_flags & _TIF_SIGPENDING)
5a157d5b DM	566	do_signal(regs, orig_i0);
	567	if (thread_info_flags & _TIF_NOTIFY_RESUME) {
	568	clear_thread_flag(TIF_NOTIFY_RESUME);
	569	tracehook_notify_resume(regs);
	570	}
	571	}
	572
1da177e4 LT	573	asmlinkage int
	574	do_sys_sigstack(struct sigstack __user ssptr, struct sigstack __user ossptr,
	575	unsigned long sp)
	576	{
	577	int ret = -EFAULT;
	578
	579	/* First see if old state is wanted. */
	580	if (ossptr) {
	581	if (put_user(current->sas_ss_sp + current->sas_ss_size,
	582	&ossptr->the_stack) \|\|
	583	__put_user(on_sig_stack(sp), &ossptr->cur_status))
	584	goto out;
	585	}
	586
	587	/* Now see if we want to update the new state. */
	588	if (ssptr) {
	589	char *ss_sp;
	590
	591	if (get_user(ss_sp, &ssptr->the_stack))
	592	goto out;
	593	/* If the current stack was set with sigaltstack, don't
	594	swap stacks while we are on it. */
	595	ret = -EPERM;
	596	if (current->sas_ss_sp && on_sig_stack(sp))
	597	goto out;
	598
	599	/* Since we don't know the extent of the stack, and we don't
	600	track onstack-ness, but rather calculate it, we must
	601	presume a size. Ho hum this interface is lossy. */
	602	current->sas_ss_sp = (unsigned long)ss_sp - SIGSTKSZ;
	603	current->sas_ss_size = SIGSTKSZ;
	604	}
	605	ret = 0;
	606	out:
	607	return ret;
	608	}