[people/arne_f/kernel.git] / arch / sparc / kernel / signal_32.c

// SPDX-License-Identifier: GPL-2.0
/*  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 <linux/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"
#include "kernel.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)))

/* Checks if the fp is valid.  We always build signal frames which are
 * 16-byte aligned, therefore we can always enforce that the restore
 * frame has that property as well.
 */
static inline bool invalid_frame_pointer(void __user *fp, int fplen)
{
	if ((((unsigned long) fp) & 15) || !__access_ok((unsigned long)fp, fplen))
		return true;

	return false;
}

asmlinkage void do_sigreturn(struct pt_regs *regs)
{
	unsigned long up_psr, pc, npc, ufp;
	struct signal_frame __user *sf;
	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->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 (invalid_frame_pointer(sf, sizeof(*sf)))
		goto segv_and_exit;

	if (get_user(ufp, &sf->info.si_regs.u_regs[UREG_FP]))
		goto segv_and_exit;

	if (ufp & 0x7)
		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, ufp;
	__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 (invalid_frame_pointer(sf, sizeof(*sf)))
		goto segv;

	if (get_user(ufp, &sf->regs.u_regs[UREG_FP]))
		goto segv;

	if (ufp & 0x7)
		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);
}

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 __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 |= __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
b2441318	1	// SPDX-License-Identifier: GPL-2.0
5526b7e4	2	/* linux/arch/sparc/kernel/signal.c
1da177e4 LT	3	*
	4	* Copyright (C) 1991, 1992 Linus Torvalds
	5	* Copyright (C) 1995 David S. Miller (davem@caip.rutgers.edu)
	6	* Copyright (C) 1996 Miguel de Icaza (miguel@nuclecu.unam.mx)
	7	* Copyright (C) 1997 Eddie C. Dost (ecd@skynet.be)
	8	*/
	9
1da177e4 LT	10	#include <linux/sched.h>
	11	#include <linux/kernel.h>
	12	#include <linux/signal.h>
	13	#include <linux/errno.h>
	14	#include <linux/wait.h>
	15	#include <linux/ptrace.h>
	16	#include <linux/unistd.h>
	17	#include <linux/mm.h>
	18	#include <linux/tty.h>
	19	#include <linux/smp.h>
1da177e4 LT	20	#include <linux/binfmts.h> /* do_coredum */
1da177e4 LT	21	#include <linux/bitops.h>
5a157d5b	22	#include <linux/tracehook.h>
1da177e4	23
7c0f6ba6	24	#include <linux/uaccess.h>
1da177e4	25	#include <asm/ptrace.h>
1da177e4 LT	26	#include <asm/pgalloc.h>
	27	#include <asm/pgtable.h>
	28	#include <asm/cacheflush.h> /* flush_sig_insns */
d550bbd4	29	#include <asm/switch_to.h>
1da177e4	30
5598473a	31	#include "sigutil.h"
529b17a9	32	#include "kernel.h"
5598473a	33
1da177e4 LT	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
d11c2a0d DM	64	/* Checks if the fp is valid. We always build signal frames which are
	65	* 16-byte aligned, therefore we can always enforce that the restore
	66	* frame has that property as well.
	67	*/
	68	static inline bool invalid_frame_pointer(void __user *fp, int fplen)
	69	{
	70	if ((((unsigned long) fp) & 15) \|\| !__access_ok((unsigned long)fp, fplen))
	71	return true;
	72
	73	return false;
	74	}
	75
5526b7e4	76	asmlinkage void do_sigreturn(struct pt_regs *regs)
1da177e4	77	{
d11c2a0d	78	unsigned long up_psr, pc, npc, ufp;
5526b7e4	79	struct signal_frame __user *sf;
1da177e4 LT	80	sigset_t set;
1da177e4 LT	81	__siginfo_fpu_t __user *fpu_save;
5598473a	82	__siginfo_rwin_t __user *rwin_save;
1da177e4 LT	83	int err;
1da177e4 LT	84
5526b7e4	85	/* Always make any pending restarted system calls return -EINTR */
f56141e3	86	current->restart_block.fn = do_no_restart_syscall;
5526b7e4 DM	87
	88	synchronize_user_stack();
	89
	90	sf = (struct signal_frame __user *) regs->u_regs[UREG_FP];
1da177e4 LT	91
1da177e4 LT	92	/* 1. Make sure we are not getting garbage from the user */
07b5ab3f	93	if (invalid_frame_pointer(sf, sizeof(*sf)))
d11c2a0d DM	94	goto segv_and_exit;
	95
	96	if (get_user(ufp, &sf->info.si_regs.u_regs[UREG_FP]))
1da177e4 LT	97	goto segv_and_exit;
1da177e4 LT	98
d11c2a0d	99	if (ufp & 0x7)
1da177e4 LT	100	goto segv_and_exit;
	101
	102	err = __get_user(pc, &sf->info.si_regs.pc);
	103	err \|= __get_user(npc, &sf->info.si_regs.npc);
	104
	105	if ((pc \| npc) & 3)
	106	goto segv_and_exit;
	107
	108	/* 2. Restore the state */
	109	up_psr = regs->psr;
	110	err \|= __copy_from_user(regs, &sf->info.si_regs, sizeof(struct pt_regs));
	111
	112	/* User can only change condition codes and FPU enabling in %psr. */
	113	regs->psr = (up_psr & ~(PSR_ICC \| PSR_EF))
	114	\| (regs->psr & (PSR_ICC \| PSR_EF));
	115
28e61036 DM	116	/* Prevent syscall restart. */
	117	pt_regs_clear_syscall(regs);
	118
1da177e4	119	err \|= __get_user(fpu_save, &sf->fpu_save);
1da177e4 LT	120	if (fpu_save)
1da177e4 LT	121	err \|= restore_fpu_state(regs, fpu_save);
5598473a DM	122	err \|= __get_user(rwin_save, &sf->rwin_save);
	123	if (rwin_save)
	124	err \|= restore_rwin_state(rwin_save);
1da177e4 LT	125
	126	/* This is pretty much atomic, no amount locking would prevent
	127	* the races which exist anyways.
	128	*/
	129	err \|= __get_user(set.sig[0], &sf->info.si_mask);
	130	err \|= __copy_from_user(&set.sig[1], &sf->extramask,
	131	(_NSIG_WORDS-1) * sizeof(unsigned int));
	132
	133	if (err)
	134	goto segv_and_exit;
	135
faddf598	136	set_current_blocked(&set);
1da177e4 LT	137	return;
	138
	139	segv_and_exit:
	140	force_sig(SIGSEGV, current);
	141	}
	142
1da177e4 LT	143	asmlinkage void do_rt_sigreturn(struct pt_regs *regs)
	144	{
	145	struct rt_signal_frame __user *sf;
d11c2a0d	146	unsigned int psr, pc, npc, ufp;
1da177e4	147	__siginfo_fpu_t __user *fpu_save;
5598473a	148	__siginfo_rwin_t __user *rwin_save;
1da177e4	149	sigset_t set;
1da177e4 LT	150	int err;
	151
	152	synchronize_user_stack();
	153	sf = (struct rt_signal_frame __user *) regs->u_regs[UREG_FP];
07b5ab3f	154	if (invalid_frame_pointer(sf, sizeof(*sf)))
d11c2a0d DM	155	goto segv;
	156
	157	if (get_user(ufp, &sf->regs.u_regs[UREG_FP]))
	158	goto segv;
	159
	160	if (ufp & 0x7)
1da177e4 LT	161	goto segv;
	162
	163	err = __get_user(pc, &sf->regs.pc);
	164	err \|= __get_user(npc, &sf->regs.npc);
	165	err \|= ((pc \| npc) & 0x03);
	166
	167	err \|= __get_user(regs->y, &sf->regs.y);
	168	err \|= __get_user(psr, &sf->regs.psr);
	169
	170	err \|= __copy_from_user(&regs->u_regs[UREG_G1],
	171	&sf->regs.u_regs[UREG_G1], 15 * sizeof(u32));
	172
	173	regs->psr = (regs->psr & ~PSR_ICC) \| (psr & PSR_ICC);
	174
28e61036 DM	175	/* Prevent syscall restart. */
	176	pt_regs_clear_syscall(regs);
	177
1da177e4	178	err \|= __get_user(fpu_save, &sf->fpu_save);
5598473a	179	if (!err && fpu_save)
1da177e4 LT	180	err \|= restore_fpu_state(regs, fpu_save);
1da177e4 LT	181	err \|= __copy_from_user(&set, &sf->mask, sizeof(sigset_t));
99b06feb	182	err \|= restore_altstack(&sf->stack);
1da177e4 LT	183
	184	if (err)
	185	goto segv;
	186
	187	regs->pc = pc;
	188	regs->npc = npc;
	189
5598473a DM	190	err \|= __get_user(rwin_save, &sf->rwin_save);
	191	if (!err && rwin_save) {
	192	if (restore_rwin_state(rwin_save))
	193	goto segv;
	194	}
	195
faddf598	196	set_current_blocked(&set);
1da177e4 LT	197	return;
	198	segv:
	199	force_sig(SIGSEGV, current);
	200	}
	201
08f73957	202	static inline void __user get_sigframe(struct ksignal ksig, struct pt_regs *regs, unsigned long framesize)
1da177e4	203	{
dc5dc7e6	204	unsigned long sp = regs->u_regs[UREG_FP];
1da177e4	205
dc5dc7e6 DM	206	/*
	207	* If we are on the alternate signal stack and would overflow it, don't.
	208	* Return an always-bogus address instead so we will die with SIGSEGV.
	209	*/
	210	if (on_sig_stack(sp) && !likely(on_sig_stack(sp - framesize)))
	211	return (void __user *) -1L;
1da177e4 LT	212
1da177e4 LT	213	/* This is the X/Open sanctioned signal stack switching. */
08f73957	214	sp = sigsp(sp, ksig) - framesize;
f036d9f3	215
dc5dc7e6 DM	216	/* Always align the stack frame. This handles two cases. First,
	217	* sigaltstack need not be mindful of platform specific stack
	218	* alignment. Second, if we took this signal because the stack
	219	* is not aligned properly, we'd like to take the signal cleanly
	220	* and report that.
	221	*/
f036d9f3	222	sp &= ~15UL;
dc5dc7e6	223
f036d9f3	224	return (void __user *) sp;
1da177e4 LT	225	}
1da177e4 LT	226
08f73957 AV	227	static int setup_frame(struct ksignal ksig, struct pt_regs regs,
08f73957 AV	228	sigset_t *oldset)
1da177e4	229	{
5526b7e4	230	struct signal_frame __user *sf;
5598473a DM	231	int sigframe_size, err, wsaved;
5598473a DM	232	void __user *tail;
1da177e4 LT	233
	234	/* 1. Make sure everything is clean */
	235	synchronize_user_stack();
	236
5598473a DM	237	wsaved = current_thread_info()->w_saved;
	238
	239	sigframe_size = sizeof(*sf);
	240	if (used_math())
	241	sigframe_size += sizeof(__siginfo_fpu_t);
	242	if (wsaved)
	243	sigframe_size += sizeof(__siginfo_rwin_t);
1da177e4	244
5526b7e4	245	sf = (struct signal_frame __user *)
08f73957	246	get_sigframe(ksig, regs, sigframe_size);
1da177e4	247
08f73957 AV	248	if (invalid_frame_pointer(sf, sigframe_size)) {
	249	do_exit(SIGILL);
	250	return -EINVAL;
	251	}
1da177e4	252
5598473a	253	tail = sf + 1;
1da177e4 LT	254
	255	/* 2. Save the current process state */
	256	err = __copy_to_user(&sf->info.si_regs, regs, sizeof(struct pt_regs));
	257
	258	err \|= __put_user(0, &sf->extra_size);
	259
	260	if (used_math()) {
5598473a DM	261	__siginfo_fpu_t __user *fp = tail;
	262	tail += sizeof(*fp);
	263	err \|= save_fpu_state(regs, fp);
	264	err \|= __put_user(fp, &sf->fpu_save);
1da177e4 LT	265	} else {
	266	err \|= __put_user(0, &sf->fpu_save);
	267	}
5598473a DM	268	if (wsaved) {
	269	__siginfo_rwin_t __user *rwp = tail;
	270	tail += sizeof(*rwp);
	271	err \|= save_rwin_state(wsaved, rwp);
	272	err \|= __put_user(rwp, &sf->rwin_save);
	273	} else {
	274	err \|= __put_user(0, &sf->rwin_save);
	275	}
1da177e4 LT	276
	277	err \|= __put_user(oldset->sig[0], &sf->info.si_mask);
	278	err \|= __copy_to_user(sf->extramask, &oldset->sig[1],
	279	(_NSIG_WORDS - 1) * sizeof(unsigned int));
5598473a DM	280	if (!wsaved) {
	281	err \|= __copy_to_user(sf, (char *) regs->u_regs[UREG_FP],
	282	sizeof(struct reg_window32));
	283	} else {
	284	struct reg_window32 *rp;
	285
	286	rp = &current_thread_info()->reg_window[wsaved - 1];
	287	err \|= __copy_to_user(sf, rp, sizeof(struct reg_window32));
	288	}
1da177e4	289	if (err)
08f73957	290	return err;
1da177e4 LT	291
	292	/* 3. signal handler back-trampoline and parameters */
	293	regs->u_regs[UREG_FP] = (unsigned long) sf;
08f73957	294	regs->u_regs[UREG_I0] = ksig->sig;
1da177e4 LT	295	regs->u_regs[UREG_I1] = (unsigned long) &sf->info;
	296	regs->u_regs[UREG_I2] = (unsigned long) &sf->info;
	297
	298	/* 4. signal handler */
08f73957	299	regs->pc = (unsigned long) ksig->ka.sa.sa_handler;
1da177e4 LT	300	regs->npc = (regs->pc + 4);
	301
	302	/* 5. return to kernel instructions */
08f73957 AV	303	if (ksig->ka.ka_restorer)
08f73957 AV	304	regs->u_regs[UREG_I7] = (unsigned long)ksig->ka.ka_restorer;
1da177e4 LT	305	else {
	306	regs->u_regs[UREG_I7] = (unsigned long)(&(sf->insns[0]) - 2);
	307
	308	/* mov __NR_sigreturn, %g1 */
	309	err \|= __put_user(0x821020d8, &sf->insns[0]);
	310
	311	/* t 0x10 */
	312	err \|= __put_user(0x91d02010, &sf->insns[1]);
	313	if (err)
08f73957	314	return err;
1da177e4 LT	315
	316	/* Flush instruction space. */
	317	flush_sig_insns(current->mm, (unsigned long) &(sf->insns[0]));
	318	}
392c2180	319	return 0;
1da177e4 LT	320	}
1da177e4 LT	321
08f73957 AV	322	static int setup_rt_frame(struct ksignal ksig, struct pt_regs regs,
08f73957 AV	323	sigset_t *oldset)
1da177e4 LT	324	{
1da177e4 LT	325	struct rt_signal_frame __user *sf;
5598473a DM	326	int sigframe_size, wsaved;
5598473a DM	327	void __user *tail;
1da177e4 LT	328	unsigned int psr;
	329	int err;
	330
	331	synchronize_user_stack();
5598473a DM	332	wsaved = current_thread_info()->w_saved;
	333	sigframe_size = sizeof(*sf);
	334	if (used_math())
	335	sigframe_size += sizeof(__siginfo_fpu_t);
	336	if (wsaved)
	337	sigframe_size += sizeof(__siginfo_rwin_t);
1da177e4	338	sf = (struct rt_signal_frame __user *)
08f73957 AV	339	get_sigframe(ksig, regs, sigframe_size);
	340	if (invalid_frame_pointer(sf, sigframe_size)) {
	341	do_exit(SIGILL);
	342	return -EINVAL;
	343	}
1da177e4	344
5598473a	345	tail = sf + 1;
1da177e4 LT	346	err = __put_user(regs->pc, &sf->regs.pc);
	347	err \|= __put_user(regs->npc, &sf->regs.npc);
	348	err \|= __put_user(regs->y, &sf->regs.y);
	349	psr = regs->psr;
	350	if (used_math())
	351	psr \|= PSR_EF;
	352	err \|= __put_user(psr, &sf->regs.psr);
	353	err \|= __copy_to_user(&sf->regs.u_regs, regs->u_regs, sizeof(regs->u_regs));
	354	err \|= __put_user(0, &sf->extra_size);
	355
	356	if (psr & PSR_EF) {
529b17a9	357	__siginfo_fpu_t __user *fp = tail;
5598473a DM	358	tail += sizeof(*fp);
	359	err \|= save_fpu_state(regs, fp);
	360	err \|= __put_user(fp, &sf->fpu_save);
1da177e4 LT	361	} else {
	362	err \|= __put_user(0, &sf->fpu_save);
	363	}
5598473a	364	if (wsaved) {
529b17a9	365	__siginfo_rwin_t __user *rwp = tail;
5598473a DM	366	tail += sizeof(*rwp);
	367	err \|= save_rwin_state(wsaved, rwp);
	368	err \|= __put_user(rwp, &sf->rwin_save);
	369	} else {
	370	err \|= __put_user(0, &sf->rwin_save);
	371	}
1da177e4 LT	372	err \|= __copy_to_user(&sf->mask, &oldset->sig[0], sizeof(sigset_t));
	373
	374	/* Setup sigaltstack */
99b06feb	375	err \|= __save_altstack(&sf->stack, regs->u_regs[UREG_FP]);
1da177e4	376
5598473a DM	377	if (!wsaved) {
	378	err \|= __copy_to_user(sf, (char *) regs->u_regs[UREG_FP],
	379	sizeof(struct reg_window32));
	380	} else {
	381	struct reg_window32 *rp;
	382
	383	rp = &current_thread_info()->reg_window[wsaved - 1];
	384	err \|= __copy_to_user(sf, rp, sizeof(struct reg_window32));
	385	}
1da177e4	386
08f73957	387	err \|= copy_siginfo_to_user(&sf->info, &ksig->info);
1da177e4 LT	388
1da177e4 LT	389	if (err)
08f73957	390	return err;
1da177e4 LT	391
1da177e4 LT	392	regs->u_regs[UREG_FP] = (unsigned long) sf;
08f73957	393	regs->u_regs[UREG_I0] = ksig->sig;
1da177e4 LT	394	regs->u_regs[UREG_I1] = (unsigned long) &sf->info;
	395	regs->u_regs[UREG_I2] = (unsigned long) &sf->regs;
	396
08f73957	397	regs->pc = (unsigned long) ksig->ka.sa.sa_handler;
1da177e4 LT	398	regs->npc = (regs->pc + 4);
1da177e4 LT	399
08f73957 AV	400	if (ksig->ka.ka_restorer)
08f73957 AV	401	regs->u_regs[UREG_I7] = (unsigned long)ksig->ka.ka_restorer;
1da177e4 LT	402	else {
	403	regs->u_regs[UREG_I7] = (unsigned long)(&(sf->insns[0]) - 2);
	404
	405	/* mov __NR_sigreturn, %g1 */
	406	err \|= __put_user(0x821020d8, &sf->insns[0]);
	407
	408	/* t 0x10 */
	409	err \|= __put_user(0x91d02010, &sf->insns[1]);
	410	if (err)
08f73957	411	return err;
1da177e4 LT	412
	413	/* Flush instruction space. */
	414	flush_sig_insns(current->mm, (unsigned long) &(sf->insns[0]));
	415	}
392c2180	416	return 0;
1da177e4 LT	417	}
1da177e4 LT	418
a610d6e6	419	static inline void
08f73957	420	handle_signal(struct ksignal ksig, struct pt_regs regs)
1da177e4	421	{
b7f9a11a	422	sigset_t *oldset = sigmask_to_save();
392c2180 DM	423	int err;
392c2180 DM	424
08f73957 AV	425	if (ksig->ka.sa.sa_flags & SA_SIGINFO)
08f73957 AV	426	err = setup_rt_frame(ksig, regs, oldset);
ec98c6b9	427	else
08f73957 AV	428	err = setup_frame(ksig, regs, oldset);
08f73957 AV	429	signal_setup_done(err, ksig, 0);
1da177e4 LT	430	}
	431
	432	static inline void syscall_restart(unsigned long orig_i0, struct pt_regs *regs,
	433	struct sigaction *sa)
	434	{
	435	switch(regs->u_regs[UREG_I0]) {
	436	case ERESTART_RESTARTBLOCK:
	437	case ERESTARTNOHAND:
	438	no_system_call_restart:
	439	regs->u_regs[UREG_I0] = EINTR;
	440	regs->psr \|= PSR_C;
	441	break;
	442	case ERESTARTSYS:
	443	if (!(sa->sa_flags & SA_RESTART))
	444	goto no_system_call_restart;
	445	/* fallthrough */
	446	case ERESTARTNOINTR:
	447	regs->u_regs[UREG_I0] = orig_i0;
	448	regs->pc -= 4;
	449	regs->npc -= 4;
	450	}
	451	}
	452
	453	/* Note that 'init' is a special process: it doesn't get signals it doesn't
	454	* want to handle. Thus you cannot kill init even with a SIGKILL even by
	455	* mistake.
	456	*/
5a157d5b	457	static void do_signal(struct pt_regs *regs, unsigned long orig_i0)
1da177e4	458	{
08f73957	459	struct ksignal ksig;
28e61036	460	int restart_syscall;
08f73957	461	bool has_handler;
1da177e4	462
1d299bc7 DM	463	/* It's a lot of work and synchronization to add a new ptrace
	464	* register for GDB to save and restore in order to get
	465	* orig_i0 correct for syscall restarts when debugging.
	466	*
e88d2468 DM	467	* Although it should be the case that most of the global
	468	* registers are volatile across a system call, glibc already
	469	* depends upon that fact that we preserve them. So we can't
	470	* just use any global register to save away the orig_i0 value.
	471	*
	472	* In particular %g2, %g3, %g4, and %g5 are all assumed to be
	473	* preserved across a system call trap by various pieces of
	474	* code in glibc.
	475	*
	476	* %g7 is used as the "thread register". %g6 is not used in
	477	* any fixed manner. %g6 is used as a scratch register and
	478	* a compiler temporary, but it's value is never used across
	479	* a system call. Therefore %g6 is usable for orig_i0 storage.
1d299bc7	480	*/
28e61036	481	if (pt_regs_is_syscall(regs) && (regs->psr & PSR_C))
e88d2468	482	regs->u_regs[UREG_G6] = orig_i0;
1da177e4	483
08f73957	484	has_handler = get_signal(&ksig);
28e61036 DM	485
	486	/* If the debugger messes with the program counter, it clears
	487	* the software "in syscall" bit, directing us to not perform
	488	* a syscall restart.
	489	*/
1d299bc7 DM	490	restart_syscall = 0;
	491	if (pt_regs_is_syscall(regs) && (regs->psr & PSR_C)) {
	492	restart_syscall = 1;
e88d2468	493	orig_i0 = regs->u_regs[UREG_G6];
1d299bc7 DM	494	}
1d299bc7 DM	495
08f73957	496	if (has_handler) {
28e61036	497	if (restart_syscall)
08f73957 AV	498	syscall_restart(orig_i0, regs, &ksig.ka.sa);
	499	handle_signal(&ksig, regs);
	500	} else {
	501	if (restart_syscall) {
	502	switch (regs->u_regs[UREG_I0]) {
	503	case ERESTARTNOHAND:
	504	case ERESTARTSYS:
	505	case ERESTARTNOINTR:
	506	/* replay the system call when we are done */
	507	regs->u_regs[UREG_I0] = orig_i0;
	508	regs->pc -= 4;
	509	regs->npc -= 4;
	510	pt_regs_clear_syscall(regs);
	511	case ERESTART_RESTARTBLOCK:
	512	regs->u_regs[UREG_G1] = __NR_restart_syscall;
	513	regs->pc -= 4;
	514	regs->npc -= 4;
	515	pt_regs_clear_syscall(regs);
	516	}
	517	}
	518	restore_saved_sigmask();
1da177e4	519	}
1da177e4 LT	520	}
1da177e4 LT	521
5a157d5b DM	522	void do_notify_resume(struct pt_regs *regs, unsigned long orig_i0,
	523	unsigned long thread_info_flags)
	524	{
6fd84c08	525	if (thread_info_flags & _TIF_SIGPENDING)
5a157d5b DM	526	do_signal(regs, orig_i0);
	527	if (thread_info_flags & _TIF_NOTIFY_RESUME) {
	528	clear_thread_flag(TIF_NOTIFY_RESUME);
	529	tracehook_notify_resume(regs);
	530	}
	531	}
	532
529b17a9 SR	533	asmlinkage int do_sys_sigstack(struct sigstack __user *ssptr,
	534	struct sigstack __user *ossptr,
	535	unsigned long sp)
1da177e4 LT	536	{
	537	int ret = -EFAULT;
	538
	539	/* First see if old state is wanted. */
	540	if (ossptr) {
	541	if (put_user(current->sas_ss_sp + current->sas_ss_size,
	542	&ossptr->the_stack) \|\|
	543	__put_user(on_sig_stack(sp), &ossptr->cur_status))
	544	goto out;
	545	}
	546
	547	/* Now see if we want to update the new state. */
	548	if (ssptr) {
	549	char *ss_sp;
	550
	551	if (get_user(ss_sp, &ssptr->the_stack))
	552	goto out;
	553	/* If the current stack was set with sigaltstack, don't
	554	swap stacks while we are on it. */
	555	ret = -EPERM;
	556	if (current->sas_ss_sp && on_sig_stack(sp))
	557	goto out;
	558
	559	/* Since we don't know the extent of the stack, and we don't
	560	track onstack-ness, but rather calculate it, we must
	561	presume a size. Ho hum this interface is lossy. */
	562	current->sas_ss_sp = (unsigned long)ss_sp - SIGSTKSZ;
	563	current->sas_ss_size = SIGSTKSZ;
	564	}
	565	ret = 0;
	566	out:
	567	return ret;
	568	}