[mirror_ubuntu-zesty-kernel.git] / arch / powerpc / kernel / signal_64.c

/*
 *  PowerPC version 
 *    Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
 *
 *  Derived from "arch/i386/kernel/signal.c"
 *    Copyright (C) 1991, 1992 Linus Torvalds
 *    1997-11-28  Modified for POSIX.1b signals by Richard Henderson
 *
 *  This program is free software; you can redistribute it and/or
 *  modify it under the terms of the GNU General Public License
 *  as published by the Free Software Foundation; either version
 *  2 of the License, or (at your option) any later version.
 */

#include <linux/sched.h>
#include <linux/mm.h>
#include <linux/smp.h>
#include <linux/kernel.h>
#include <linux/signal.h>
#include <linux/errno.h>
#include <linux/wait.h>
#include <linux/unistd.h>
#include <linux/stddef.h>
#include <linux/elf.h>
#include <linux/ptrace.h>
#include <linux/module.h>

#include <asm/sigcontext.h>
#include <asm/ucontext.h>
#include <asm/uaccess.h>
#include <asm/pgtable.h>
#include <asm/unistd.h>
#include <asm/cacheflush.h>
#include <asm/syscalls.h>
#include <asm/vdso.h>

#include "signal.h"

#define DEBUG_SIG 0

#define GP_REGS_SIZE	min(sizeof(elf_gregset_t), sizeof(struct pt_regs))
#define FP_REGS_SIZE	sizeof(elf_fpregset_t)

#define TRAMP_TRACEBACK	3
#define TRAMP_SIZE	6

/*
 * When we have signals to deliver, we set up on the user stack,
 * going down from the original stack pointer:
 *	1) a rt_sigframe struct which contains the ucontext	
 *	2) a gap of __SIGNAL_FRAMESIZE bytes which acts as a dummy caller
 *	   frame for the signal handler.
 */

struct rt_sigframe {
	/* sys_rt_sigreturn requires the ucontext be the first field */
	struct ucontext uc;
	unsigned long _unused[2];
	unsigned int tramp[TRAMP_SIZE];
	struct siginfo __user *pinfo;
	void __user *puc;
	struct siginfo info;
	/* 64 bit ABI allows for 288 bytes below sp before decrementing it. */
	char abigap[288];
} __attribute__ ((aligned (16)));

/*
 * Set up the sigcontext for the signal frame.
 */

static long setup_sigcontext(struct sigcontext __user *sc, struct pt_regs *regs,
		 int signr, sigset_t *set, unsigned long handler)
{
	/* When CONFIG_ALTIVEC is set, we _always_ setup v_regs even if the
	 * process never used altivec yet (MSR_VEC is zero in pt_regs of
	 * the context). This is very important because we must ensure we
	 * don't lose the VRSAVE content that may have been set prior to
	 * the process doing its first vector operation
	 * Userland shall check AT_HWCAP to know wether it can rely on the
	 * v_regs pointer or not
	 */
#ifdef CONFIG_ALTIVEC
	elf_vrreg_t __user *v_regs = (elf_vrreg_t __user *)(((unsigned long)sc->vmx_reserve + 15) & ~0xful);
#endif
	long err = 0;

	flush_fp_to_thread(current);

#ifdef CONFIG_ALTIVEC
	err |= __put_user(v_regs, &sc->v_regs);

	/* save altivec registers */
	if (current->thread.used_vr) {
		flush_altivec_to_thread(current);
		/* Copy 33 vec registers (vr0..31 and vscr) to the stack */
		err |= __copy_to_user(v_regs, current->thread.vr, 33 * sizeof(vector128));
		/* set MSR_VEC in the MSR value in the frame to indicate that sc->v_reg)
		 * contains valid data.
		 */
		regs->msr |= MSR_VEC;
	}
	/* We always copy to/from vrsave, it's 0 if we don't have or don't
	 * use altivec.
	 */
	err |= __put_user(current->thread.vrsave, (u32 __user *)&v_regs[33]);
#else /* CONFIG_ALTIVEC */
	err |= __put_user(0, &sc->v_regs);
#endif /* CONFIG_ALTIVEC */
	err |= __put_user(&sc->gp_regs, &sc->regs);
	WARN_ON(!FULL_REGS(regs));
	err |= __copy_to_user(&sc->gp_regs, regs, GP_REGS_SIZE);
	err |= __copy_to_user(&sc->fp_regs, &current->thread.fpr, FP_REGS_SIZE);
	err |= __put_user(signr, &sc->signal);
	err |= __put_user(handler, &sc->handler);
	if (set != NULL)
		err |=  __put_user(set->sig[0], &sc->oldmask);

	return err;
}

/*
 * Restore the sigcontext from the signal frame.
 */

static long restore_sigcontext(struct pt_regs *regs, sigset_t *set, int sig,
			      struct sigcontext __user *sc)
{
#ifdef CONFIG_ALTIVEC
	elf_vrreg_t __user *v_regs;
#endif
	unsigned long err = 0;
	unsigned long save_r13 = 0;
	elf_greg_t *gregs = (elf_greg_t *)regs;
	unsigned long msr;
	int i;

	/* If this is not a signal return, we preserve the TLS in r13 */
	if (!sig)
		save_r13 = regs->gpr[13];

	/* copy everything before MSR */
	err |= __copy_from_user(regs, &sc->gp_regs,
				PT_MSR*sizeof(unsigned long));

	/* get MSR separately, transfer the LE bit if doing signal return */
	err |= __get_user(msr, &sc->gp_regs[PT_MSR]);
	if (sig)
		regs->msr = (regs->msr & ~MSR_LE) | (msr & MSR_LE);

	/* skip SOFTE */
	for (i = PT_MSR+1; i <= PT_RESULT; i++) {
		if (i == PT_SOFTE)
			continue;
		err |= __get_user(gregs[i], &sc->gp_regs[i]);
	}

	if (!sig)
		regs->gpr[13] = save_r13;
	if (set != NULL)
		err |=  __get_user(set->sig[0], &sc->oldmask);

	/*
	 * Do this before updating the thread state in
	 * current->thread.fpr/vr.  That way, if we get preempted
	 * and another task grabs the FPU/Altivec, it won't be
	 * tempted to save the current CPU state into the thread_struct
	 * and corrupt what we are writing there.
	 */
	discard_lazy_cpu_state();

	/*
	 * Force reload of FP/VEC.
	 * This has to be done before copying stuff into current->thread.fpr/vr
	 * for the reasons explained in the previous comment.
	 */
	regs->msr &= ~(MSR_FP | MSR_FE0 | MSR_FE1 | MSR_VEC);

	err |= __copy_from_user(&current->thread.fpr, &sc->fp_regs, FP_REGS_SIZE);

#ifdef CONFIG_ALTIVEC
	err |= __get_user(v_regs, &sc->v_regs);
	if (err)
		return err;
	if (v_regs && !access_ok(VERIFY_READ, v_regs, 34 * sizeof(vector128)))
		return -EFAULT;
	/* Copy 33 vec registers (vr0..31 and vscr) from the stack */
	if (v_regs != 0 && (msr & MSR_VEC) != 0)
		err |= __copy_from_user(current->thread.vr, v_regs,
					33 * sizeof(vector128));
	else if (current->thread.used_vr)
		memset(current->thread.vr, 0, 33 * sizeof(vector128));
	/* Always get VRSAVE back */
	if (v_regs != 0)
		err |= __get_user(current->thread.vrsave, (u32 __user *)&v_regs[33]);
	else
		current->thread.vrsave = 0;
#endif /* CONFIG_ALTIVEC */

	return err;
}

/*
 * Setup the trampoline code on the stack
 */
static long setup_trampoline(unsigned int syscall, unsigned int __user *tramp)
{
	int i;
	long err = 0;

	/* addi r1, r1, __SIGNAL_FRAMESIZE  # Pop the dummy stackframe */
	err |= __put_user(0x38210000UL | (__SIGNAL_FRAMESIZE & 0xffff), &tramp[0]);
	/* li r0, __NR_[rt_]sigreturn| */
	err |= __put_user(0x38000000UL | (syscall & 0xffff), &tramp[1]);
	/* sc */
	err |= __put_user(0x44000002UL, &tramp[2]);

	/* Minimal traceback info */
	for (i=TRAMP_TRACEBACK; i < TRAMP_SIZE ;i++)
		err |= __put_user(0, &tramp[i]);

	if (!err)
		flush_icache_range((unsigned long) &tramp[0],
			   (unsigned long) &tramp[TRAMP_SIZE]);

	return err;
}

/*
 * Handle {get,set,swap}_context operations
 */
int sys_swapcontext(struct ucontext __user *old_ctx,
		    struct ucontext __user *new_ctx,
		    long ctx_size, long r6, long r7, long r8, struct pt_regs *regs)
{
	unsigned char tmp;
	sigset_t set;

	/* Context size is for future use. Right now, we only make sure
	 * we are passed something we understand
	 */
	if (ctx_size < sizeof(struct ucontext))
		return -EINVAL;

	if (old_ctx != NULL) {
		if (!access_ok(VERIFY_WRITE, old_ctx, sizeof(*old_ctx))
		    || setup_sigcontext(&old_ctx->uc_mcontext, regs, 0, NULL, 0)
		    || __copy_to_user(&old_ctx->uc_sigmask,
				      &current->blocked, sizeof(sigset_t)))
			return -EFAULT;
	}
	if (new_ctx == NULL)
		return 0;
	if (!access_ok(VERIFY_READ, new_ctx, sizeof(*new_ctx))
	    || __get_user(tmp, (u8 __user *) new_ctx)
	    || __get_user(tmp, (u8 __user *) (new_ctx + 1) - 1))
		return -EFAULT;

	/*
	 * If we get a fault copying the context into the kernel's
	 * image of the user's registers, we can't just return -EFAULT
	 * because the user's registers will be corrupted.  For instance
	 * the NIP value may have been updated but not some of the
	 * other registers.  Given that we have done the access_ok
	 * and successfully read the first and last bytes of the region
	 * above, this should only happen in an out-of-memory situation
	 * or if another thread unmaps the region containing the context.
	 * We kill the task with a SIGSEGV in this situation.
	 */

	if (__copy_from_user(&set, &new_ctx->uc_sigmask, sizeof(set)))
		do_exit(SIGSEGV);
	restore_sigmask(&set);
	if (restore_sigcontext(regs, NULL, 0, &new_ctx->uc_mcontext))
		do_exit(SIGSEGV);

	/* This returns like rt_sigreturn */
	set_thread_flag(TIF_RESTOREALL);
	return 0;
}


/*
 * Do a signal return; undo the signal stack.
 */

int sys_rt_sigreturn(unsigned long r3, unsigned long r4, unsigned long r5,
		     unsigned long r6, unsigned long r7, unsigned long r8,
		     struct pt_regs *regs)
{
	struct ucontext __user *uc = (struct ucontext __user *)regs->gpr[1];
	sigset_t set;

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

	if (!access_ok(VERIFY_READ, uc, sizeof(*uc)))
		goto badframe;

	if (__copy_from_user(&set, &uc->uc_sigmask, sizeof(set)))
		goto badframe;
	restore_sigmask(&set);
	if (restore_sigcontext(regs, NULL, 1, &uc->uc_mcontext))
		goto badframe;

	/* do_sigaltstack expects a __user pointer and won't modify
	 * what's in there anyway
	 */
	do_sigaltstack(&uc->uc_stack, NULL, regs->gpr[1]);

	set_thread_flag(TIF_RESTOREALL);
	return 0;

badframe:
#if DEBUG_SIG
	printk("badframe in sys_rt_sigreturn, regs=%p uc=%p &uc->uc_mcontext=%p\n",
	       regs, uc, &uc->uc_mcontext);
#endif
	force_sig(SIGSEGV, current);
	return 0;
}

int handle_rt_signal64(int signr, struct k_sigaction *ka, siginfo_t *info,
		sigset_t *set, struct pt_regs *regs)
{
	/* Handler is *really* a pointer to the function descriptor for
	 * the signal routine.  The first entry in the function
	 * descriptor is the entry address of signal and the second
	 * entry is the TOC value we need to use.
	 */
	func_descr_t __user *funct_desc_ptr;
	struct rt_sigframe __user *frame;
	unsigned long newsp = 0;
	long err = 0;

	frame = get_sigframe(ka, regs, sizeof(*frame));
	if (unlikely(frame == NULL))
		goto badframe;

	err |= __put_user(&frame->info, &frame->pinfo);
	err |= __put_user(&frame->uc, &frame->puc);
	err |= copy_siginfo_to_user(&frame->info, info);
	if (err)
		goto badframe;

	/* Create the ucontext.  */
	err |= __put_user(0, &frame->uc.uc_flags);
	err |= __put_user(0, &frame->uc.uc_link);
	err |= __put_user(current->sas_ss_sp, &frame->uc.uc_stack.ss_sp);
	err |= __put_user(sas_ss_flags(regs->gpr[1]),
			  &frame->uc.uc_stack.ss_flags);
	err |= __put_user(current->sas_ss_size, &frame->uc.uc_stack.ss_size);
	err |= setup_sigcontext(&frame->uc.uc_mcontext, regs, signr, NULL,
				(unsigned long)ka->sa.sa_handler);
	err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
	if (err)
		goto badframe;

	/* Make sure signal handler doesn't get spurious FP exceptions */
	current->thread.fpscr.val = 0;

	/* Set up to return from userspace. */
	if (vdso64_rt_sigtramp && current->mm->context.vdso_base) {
		regs->link = current->mm->context.vdso_base + vdso64_rt_sigtramp;
	} else {
		err |= setup_trampoline(__NR_rt_sigreturn, &frame->tramp[0]);
		if (err)
			goto badframe;
		regs->link = (unsigned long) &frame->tramp[0];
	}
	funct_desc_ptr = (func_descr_t __user *) ka->sa.sa_handler;

	/* Allocate a dummy caller frame for the signal handler. */
	newsp = ((unsigned long)frame) - __SIGNAL_FRAMESIZE;
	err |= put_user(regs->gpr[1], (unsigned long __user *)newsp);

	/* Set up "regs" so we "return" to the signal handler. */
	err |= get_user(regs->nip, &funct_desc_ptr->entry);
	/* enter the signal handler in big-endian mode */
	regs->msr &= ~MSR_LE;
	regs->gpr[1] = newsp;
	err |= get_user(regs->gpr[2], &funct_desc_ptr->toc);
	regs->gpr[3] = signr;
	regs->result = 0;
	if (ka->sa.sa_flags & SA_SIGINFO) {
		err |= get_user(regs->gpr[4], (unsigned long __user *)&frame->pinfo);
		err |= get_user(regs->gpr[5], (unsigned long __user *)&frame->puc);
		regs->gpr[6] = (unsigned long) frame;
	} else {
		regs->gpr[4] = (unsigned long)&frame->uc.uc_mcontext;
	}
	if (err)
		goto badframe;

	return 1;

badframe:
#if DEBUG_SIG
	printk("badframe in setup_rt_frame, regs=%p frame=%p newsp=%lx\n",
	       regs, frame, newsp);
#endif
	force_sigsegv(signr, current);
	return 0;
}
Commit	Line	Data
1da177e4	1	/*
1da177e4 LT	2	* PowerPC version
	3	* Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
	4	*
	5	* Derived from "arch/i386/kernel/signal.c"
	6	* Copyright (C) 1991, 1992 Linus Torvalds
	7	* 1997-11-28 Modified for POSIX.1b signals by Richard Henderson
	8	*
	9	* This program is free software; you can redistribute it and/or
	10	* modify it under the terms of the GNU General Public License
	11	* as published by the Free Software Foundation; either version
	12	* 2 of the License, or (at your option) any later version.
	13	*/
	14
1da177e4 LT	15	#include <linux/sched.h>
	16	#include <linux/mm.h>
	17	#include <linux/smp.h>
1da177e4 LT	18	#include <linux/kernel.h>
	19	#include <linux/signal.h>
	20	#include <linux/errno.h>
	21	#include <linux/wait.h>
	22	#include <linux/unistd.h>
	23	#include <linux/stddef.h>
	24	#include <linux/elf.h>
	25	#include <linux/ptrace.h>
	26	#include <linux/module.h>
	27
	28	#include <asm/sigcontext.h>
	29	#include <asm/ucontext.h>
	30	#include <asm/uaccess.h>
	31	#include <asm/pgtable.h>
1da177e4 LT	32	#include <asm/unistd.h>
1da177e4 LT	33	#include <asm/cacheflush.h>
a7f31841	34	#include <asm/syscalls.h>
1da177e4 LT	35	#include <asm/vdso.h>
1da177e4 LT	36
22e38f29	37	#include "signal.h"
1da177e4	38
1da177e4	39	#define DEBUG_SIG 0
1da177e4	40
6741f3a7	41	#define GP_REGS_SIZE min(sizeof(elf_gregset_t), sizeof(struct pt_regs))
1da177e4 LT	42	#define FP_REGS_SIZE sizeof(elf_fpregset_t)
	43
	44	#define TRAMP_TRACEBACK 3
	45	#define TRAMP_SIZE 6
	46
	47	/*
	48	* When we have signals to deliver, we set up on the user stack,
	49	* going down from the original stack pointer:
	50	* 1) a rt_sigframe struct which contains the ucontext
	51	* 2) a gap of __SIGNAL_FRAMESIZE bytes which acts as a dummy caller
	52	* frame for the signal handler.
	53	*/
	54
	55	struct rt_sigframe {
	56	/* sys_rt_sigreturn requires the ucontext be the first field */
	57	struct ucontext uc;
	58	unsigned long _unused[2];
	59	unsigned int tramp[TRAMP_SIZE];
29e646df AV	60	struct siginfo __user *pinfo;
29e646df AV	61	void __user *puc;
1da177e4 LT	62	struct siginfo info;
	63	/* 64 bit ABI allows for 288 bytes below sp before decrementing it. */
	64	char abigap[288];
	65	} __attribute__ ((aligned (16)));
	66
1da177e4 LT	67	/*
	68	* Set up the sigcontext for the signal frame.
	69	*/
	70
	71	static long setup_sigcontext(struct sigcontext __user sc, struct pt_regs regs,
	72	int signr, sigset_t *set, unsigned long handler)
	73	{
	74	/* When CONFIG_ALTIVEC is set, we _always_ setup v_regs even if the
	75	* process never used altivec yet (MSR_VEC is zero in pt_regs of
	76	* the context). This is very important because we must ensure we
	77	* don't lose the VRSAVE content that may have been set prior to
	78	* the process doing its first vector operation
	79	* Userland shall check AT_HWCAP to know wether it can rely on the
	80	* v_regs pointer or not
	81	*/
	82	#ifdef CONFIG_ALTIVEC
	83	elf_vrreg_t __user v_regs = (elf_vrreg_t __user )(((unsigned long)sc->vmx_reserve + 15) & ~0xful);
	84	#endif
	85	long err = 0;
	86
	87	flush_fp_to_thread(current);
	88
1da177e4 LT	89	#ifdef CONFIG_ALTIVEC
	90	err \|= __put_user(v_regs, &sc->v_regs);
	91
	92	/* save altivec registers */
	93	if (current->thread.used_vr) {
	94	flush_altivec_to_thread(current);
	95	/* Copy 33 vec registers (vr0..31 and vscr) to the stack */
	96	err \|= __copy_to_user(v_regs, current->thread.vr, 33 * sizeof(vector128));
	97	/* set MSR_VEC in the MSR value in the frame to indicate that sc->v_reg)
	98	* contains valid data.
	99	*/
	100	regs->msr \|= MSR_VEC;
	101	}
	102	/* We always copy to/from vrsave, it's 0 if we don't have or don't
	103	* use altivec.
	104	*/
	105	err \|= __put_user(current->thread.vrsave, (u32 __user *)&v_regs[33]);
	106	#else /* CONFIG_ALTIVEC */
	107	err \|= __put_user(0, &sc->v_regs);
	108	#endif /* CONFIG_ALTIVEC */
	109	err \|= __put_user(&sc->gp_regs, &sc->regs);
1bd79336	110	WARN_ON(!FULL_REGS(regs));
1da177e4 LT	111	err \|= __copy_to_user(&sc->gp_regs, regs, GP_REGS_SIZE);
	112	err \|= __copy_to_user(&sc->fp_regs, &current->thread.fpr, FP_REGS_SIZE);
	113	err \|= __put_user(signr, &sc->signal);
	114	err \|= __put_user(handler, &sc->handler);
	115	if (set != NULL)
	116	err \|= __put_user(set->sig[0], &sc->oldmask);
	117
	118	return err;
	119	}
	120
	121	/*
	122	* Restore the sigcontext from the signal frame.
	123	*/
	124
	125	static long restore_sigcontext(struct pt_regs regs, sigset_t set, int sig,
	126	struct sigcontext __user *sc)
	127	{
	128	#ifdef CONFIG_ALTIVEC
	129	elf_vrreg_t __user *v_regs;
	130	#endif
	131	unsigned long err = 0;
	132	unsigned long save_r13 = 0;
	133	elf_greg_t gregs = (elf_greg_t )regs;
1da177e4	134	unsigned long msr;
1da177e4 LT	135	int i;
	136
	137	/* If this is not a signal return, we preserve the TLS in r13 */
	138	if (!sig)
	139	save_r13 = regs->gpr[13];
	140
	141	/* copy everything before MSR */
	142	err \|= __copy_from_user(regs, &sc->gp_regs,
	143	PT_MSR*sizeof(unsigned long));
	144
fab5db97 PM	145	/* get MSR separately, transfer the LE bit if doing signal return */
	146	err \|= __get_user(msr, &sc->gp_regs[PT_MSR]);
	147	if (sig)
	148	regs->msr = (regs->msr & ~MSR_LE) \| (msr & MSR_LE);
	149
	150	/* skip SOFTE */
1da177e4 LT	151	for (i = PT_MSR+1; i <= PT_RESULT; i++) {
	152	if (i == PT_SOFTE)
	153	continue;
	154	err \|= __get_user(gregs[i], &sc->gp_regs[i]);
	155	}
	156
	157	if (!sig)
	158	regs->gpr[13] = save_r13;
1da177e4 LT	159	if (set != NULL)
	160	err \|= __get_user(set->sig[0], &sc->oldmask);
	161
5388fb10 PM	162	/*
	163	* Do this before updating the thread state in
	164	* current->thread.fpr/vr. That way, if we get preempted
	165	* and another task grabs the FPU/Altivec, it won't be
	166	* tempted to save the current CPU state into the thread_struct
	167	* and corrupt what we are writing there.
	168	*/
	169	discard_lazy_cpu_state();
	170
ae62fbb5 PM	171	/*
	172	* Force reload of FP/VEC.
	173	* This has to be done before copying stuff into current->thread.fpr/vr
	174	* for the reasons explained in the previous comment.
	175	*/
	176	regs->msr &= ~(MSR_FP \| MSR_FE0 \| MSR_FE1 \| MSR_VEC);
	177
5388fb10 PM	178	err \|= __copy_from_user(&current->thread.fpr, &sc->fp_regs, FP_REGS_SIZE);
5388fb10 PM	179
1da177e4 LT	180	#ifdef CONFIG_ALTIVEC
1da177e4 LT	181	err \|= __get_user(v_regs, &sc->v_regs);
1da177e4 LT	182	if (err)
1da177e4 LT	183	return err;
7c85d1f9 PM	184	if (v_regs && !access_ok(VERIFY_READ, v_regs, 34 * sizeof(vector128)))
7c85d1f9 PM	185	return -EFAULT;
1da177e4 LT	186	/* Copy 33 vec registers (vr0..31 and vscr) from the stack */
	187	if (v_regs != 0 && (msr & MSR_VEC) != 0)
	188	err \|= __copy_from_user(current->thread.vr, v_regs,
	189	33 * sizeof(vector128));
	190	else if (current->thread.used_vr)
	191	memset(current->thread.vr, 0, 33 * sizeof(vector128));
	192	/* Always get VRSAVE back */
	193	if (v_regs != 0)
	194	err \|= __get_user(current->thread.vrsave, (u32 __user *)&v_regs[33]);
	195	else
	196	current->thread.vrsave = 0;
	197	#endif /* CONFIG_ALTIVEC */
	198
1da177e4 LT	199	return err;
	200	}
	201
1da177e4 LT	202	/*
	203	* Setup the trampoline code on the stack
	204	*/
	205	static long setup_trampoline(unsigned int syscall, unsigned int __user *tramp)
	206	{
	207	int i;
	208	long err = 0;
	209
	210	/* addi r1, r1, __SIGNAL_FRAMESIZE # Pop the dummy stackframe */
	211	err \|= __put_user(0x38210000UL \| (__SIGNAL_FRAMESIZE & 0xffff), &tramp[0]);
	212	/* li r0, __NR_[rt_]sigreturn\| */
	213	err \|= __put_user(0x38000000UL \| (syscall & 0xffff), &tramp[1]);
	214	/* sc */
	215	err \|= __put_user(0x44000002UL, &tramp[2]);
	216
	217	/* Minimal traceback info */
	218	for (i=TRAMP_TRACEBACK; i < TRAMP_SIZE ;i++)
	219	err \|= __put_user(0, &tramp[i]);
	220
	221	if (!err)
	222	flush_icache_range((unsigned long) &tramp[0],
	223	(unsigned long) &tramp[TRAMP_SIZE]);
	224
	225	return err;
	226	}
	227
1da177e4 LT	228	/*
	229	* Handle {get,set,swap}_context operations
	230	*/
	231	int sys_swapcontext(struct ucontext __user *old_ctx,
	232	struct ucontext __user *new_ctx,
	233	long ctx_size, long r6, long r7, long r8, struct pt_regs *regs)
	234	{
	235	unsigned char tmp;
	236	sigset_t set;
	237
	238	/* Context size is for future use. Right now, we only make sure
	239	* we are passed something we understand
	240	*/
	241	if (ctx_size < sizeof(struct ucontext))
	242	return -EINVAL;
	243
	244	if (old_ctx != NULL) {
	245	if (!access_ok(VERIFY_WRITE, old_ctx, sizeof(*old_ctx))
	246	\|\| setup_sigcontext(&old_ctx->uc_mcontext, regs, 0, NULL, 0)
	247	\|\| __copy_to_user(&old_ctx->uc_sigmask,
	248	&current->blocked, sizeof(sigset_t)))
	249	return -EFAULT;
	250	}
	251	if (new_ctx == NULL)
	252	return 0;
	253	if (!access_ok(VERIFY_READ, new_ctx, sizeof(*new_ctx))
	254	\|\| __get_user(tmp, (u8 __user *) new_ctx)
	255	\|\| __get_user(tmp, (u8 __user *) (new_ctx + 1) - 1))
	256	return -EFAULT;
	257
	258	/*
	259	* If we get a fault copying the context into the kernel's
	260	* image of the user's registers, we can't just return -EFAULT
	261	* because the user's registers will be corrupted. For instance
	262	* the NIP value may have been updated but not some of the
	263	* other registers. Given that we have done the access_ok
	264	* and successfully read the first and last bytes of the region
	265	* above, this should only happen in an out-of-memory situation
	266	* or if another thread unmaps the region containing the context.
	267	* We kill the task with a SIGSEGV in this situation.
	268	*/
	269
	270	if (__copy_from_user(&set, &new_ctx->uc_sigmask, sizeof(set)))
	271	do_exit(SIGSEGV);
	272	restore_sigmask(&set);
	273	if (restore_sigcontext(regs, NULL, 0, &new_ctx->uc_mcontext))
	274	do_exit(SIGSEGV);
	275
	276	/* This returns like rt_sigreturn */
401d1f02	277	set_thread_flag(TIF_RESTOREALL);
1da177e4 LT	278	return 0;
	279	}
	280
	281
	282	/*
	283	* Do a signal return; undo the signal stack.
	284	*/
	285
	286	int sys_rt_sigreturn(unsigned long r3, unsigned long r4, unsigned long r5,
	287	unsigned long r6, unsigned long r7, unsigned long r8,
	288	struct pt_regs *regs)
	289	{
	290	struct ucontext __user uc = (struct ucontext __user )regs->gpr[1];
	291	sigset_t set;
	292
	293	/* Always make any pending restarted system calls return -EINTR */
	294	current_thread_info()->restart_block.fn = do_no_restart_syscall;
	295
	296	if (!access_ok(VERIFY_READ, uc, sizeof(*uc)))
	297	goto badframe;
	298
	299	if (__copy_from_user(&set, &uc->uc_sigmask, sizeof(set)))
	300	goto badframe;
	301	restore_sigmask(&set);
	302	if (restore_sigcontext(regs, NULL, 1, &uc->uc_mcontext))
	303	goto badframe;
	304
	305	/* do_sigaltstack expects a __user pointer and won't modify
	306	* what's in there anyway
	307	*/
	308	do_sigaltstack(&uc->uc_stack, NULL, regs->gpr[1]);
	309
401d1f02 DW	310	set_thread_flag(TIF_RESTOREALL);
401d1f02 DW	311	return 0;
1da177e4 LT	312
	313	badframe:
	314	#if DEBUG_SIG
	315	printk("badframe in sys_rt_sigreturn, regs=%p uc=%p &uc->uc_mcontext=%p\n",
	316	regs, uc, &uc->uc_mcontext);
	317	#endif
	318	force_sig(SIGSEGV, current);
	319	return 0;
	320	}
	321
f478f543	322	int handle_rt_signal64(int signr, struct k_sigaction ka, siginfo_t info,
1da177e4 LT	323	sigset_t set, struct pt_regs regs)
	324	{
	325	/* Handler is really a pointer to the function descriptor for
	326	* the signal routine. The first entry in the function
	327	* descriptor is the entry address of signal and the second
	328	* entry is the TOC value we need to use.
	329	*/
	330	func_descr_t __user *funct_desc_ptr;
	331	struct rt_sigframe __user *frame;
	332	unsigned long newsp = 0;
	333	long err = 0;
	334
	335	frame = get_sigframe(ka, regs, sizeof(*frame));
a3f61dc0	336	if (unlikely(frame == NULL))
1da177e4 LT	337	goto badframe;
	338
	339	err \|= __put_user(&frame->info, &frame->pinfo);
	340	err \|= __put_user(&frame->uc, &frame->puc);
	341	err \|= copy_siginfo_to_user(&frame->info, info);
	342	if (err)
	343	goto badframe;
	344
	345	/* Create the ucontext. */
	346	err \|= __put_user(0, &frame->uc.uc_flags);
	347	err \|= __put_user(0, &frame->uc.uc_link);
	348	err \|= __put_user(current->sas_ss_sp, &frame->uc.uc_stack.ss_sp);
	349	err \|= __put_user(sas_ss_flags(regs->gpr[1]),
	350	&frame->uc.uc_stack.ss_flags);
	351	err \|= __put_user(current->sas_ss_size, &frame->uc.uc_stack.ss_size);
	352	err \|= setup_sigcontext(&frame->uc.uc_mcontext, regs, signr, NULL,
	353	(unsigned long)ka->sa.sa_handler);
	354	err \|= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
	355	if (err)
	356	goto badframe;
	357
cc657f53 PM	358	/* Make sure signal handler doesn't get spurious FP exceptions */
	359	current->thread.fpscr.val = 0;
	360
1da177e4	361	/* Set up to return from userspace. */
a5bba930 BH	362	if (vdso64_rt_sigtramp && current->mm->context.vdso_base) {
a5bba930 BH	363	regs->link = current->mm->context.vdso_base + vdso64_rt_sigtramp;
1da177e4 LT	364	} else {
	365	err \|= setup_trampoline(__NR_rt_sigreturn, &frame->tramp[0]);
	366	if (err)
	367	goto badframe;
	368	regs->link = (unsigned long) &frame->tramp[0];
	369	}
	370	funct_desc_ptr = (func_descr_t __user *) ka->sa.sa_handler;
	371
	372	/* Allocate a dummy caller frame for the signal handler. */
a3f61dc0	373	newsp = ((unsigned long)frame) - __SIGNAL_FRAMESIZE;
1da177e4 LT	374	err \|= put_user(regs->gpr[1], (unsigned long __user *)newsp);
	375
	376	/* Set up "regs" so we "return" to the signal handler. */
	377	err \|= get_user(regs->nip, &funct_desc_ptr->entry);
fab5db97 PM	378	/* enter the signal handler in big-endian mode */
fab5db97 PM	379	regs->msr &= ~MSR_LE;
1da177e4 LT	380	regs->gpr[1] = newsp;
	381	err \|= get_user(regs->gpr[2], &funct_desc_ptr->toc);
	382	regs->gpr[3] = signr;
	383	regs->result = 0;
	384	if (ka->sa.sa_flags & SA_SIGINFO) {
	385	err \|= get_user(regs->gpr[4], (unsigned long __user *)&frame->pinfo);
	386	err \|= get_user(regs->gpr[5], (unsigned long __user *)&frame->puc);
	387	regs->gpr[6] = (unsigned long) frame;
	388	} else {
	389	regs->gpr[4] = (unsigned long)&frame->uc.uc_mcontext;
	390	}
	391	if (err)
	392	goto badframe;
	393
1da177e4 LT	394	return 1;
	395
	396	badframe:
	397	#if DEBUG_SIG
	398	printk("badframe in setup_rt_frame, regs=%p frame=%p newsp=%lx\n",
	399	regs, frame, newsp);
	400	#endif
	401	force_sigsegv(signr, current);
	402	return 0;
	403	}