[linux-2.6-block.git] / arch / arm64 / kernel / signal32.c

// SPDX-License-Identifier: GPL-2.0-only
/*
 * Based on arch/arm/kernel/signal.c
 *
 * Copyright (C) 1995-2009 Russell King
 * Copyright (C) 2012 ARM Ltd.
 * Modified by Will Deacon <will.deacon@arm.com>
 */

#include <linux/compat.h>
#include <linux/signal.h>
#include <linux/syscalls.h>
#include <linux/ratelimit.h>

#include <asm/esr.h>
#include <asm/fpsimd.h>
#include <asm/signal32.h>
#include <asm/traps.h>
#include <linux/uaccess.h>
#include <asm/unistd.h>

struct compat_sigcontext {
	/* We always set these two fields to 0 */
	compat_ulong_t			trap_no;
	compat_ulong_t			error_code;

	compat_ulong_t			oldmask;
	compat_ulong_t			arm_r0;
	compat_ulong_t			arm_r1;
	compat_ulong_t			arm_r2;
	compat_ulong_t			arm_r3;
	compat_ulong_t			arm_r4;
	compat_ulong_t			arm_r5;
	compat_ulong_t			arm_r6;
	compat_ulong_t			arm_r7;
	compat_ulong_t			arm_r8;
	compat_ulong_t			arm_r9;
	compat_ulong_t			arm_r10;
	compat_ulong_t			arm_fp;
	compat_ulong_t			arm_ip;
	compat_ulong_t			arm_sp;
	compat_ulong_t			arm_lr;
	compat_ulong_t			arm_pc;
	compat_ulong_t			arm_cpsr;
	compat_ulong_t			fault_address;
};

struct compat_ucontext {
	compat_ulong_t			uc_flags;
	compat_uptr_t			uc_link;
	compat_stack_t			uc_stack;
	struct compat_sigcontext	uc_mcontext;
	compat_sigset_t			uc_sigmask;
	int		__unused[32 - (sizeof (compat_sigset_t) / sizeof (int))];
	compat_ulong_t	uc_regspace[128] __attribute__((__aligned__(8)));
};

struct compat_vfp_sigframe {
	compat_ulong_t	magic;
	compat_ulong_t	size;
	struct compat_user_vfp {
		compat_u64	fpregs[32];
		compat_ulong_t	fpscr;
	} ufp;
	struct compat_user_vfp_exc {
		compat_ulong_t	fpexc;
		compat_ulong_t	fpinst;
		compat_ulong_t	fpinst2;
	} ufp_exc;
} __attribute__((__aligned__(8)));

#define VFP_MAGIC		0x56465001
#define VFP_STORAGE_SIZE	sizeof(struct compat_vfp_sigframe)

#define FSR_WRITE_SHIFT		(11)

struct compat_aux_sigframe {
	struct compat_vfp_sigframe	vfp;

	/* Something that isn't a valid magic number for any coprocessor.  */
	unsigned long			end_magic;
} __attribute__((__aligned__(8)));

struct compat_sigframe {
	struct compat_ucontext	uc;
	compat_ulong_t		retcode[2];
};

struct compat_rt_sigframe {
	struct compat_siginfo info;
	struct compat_sigframe sig;
};

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

static inline int put_sigset_t(compat_sigset_t __user *uset, sigset_t *set)
{
	compat_sigset_t	cset;

	cset.sig[0] = set->sig[0] & 0xffffffffull;
	cset.sig[1] = set->sig[0] >> 32;

	return copy_to_user(uset, &cset, sizeof(*uset));
}

static inline int get_sigset_t(sigset_t *set,
			       const compat_sigset_t __user *uset)
{
	compat_sigset_t s32;

	if (copy_from_user(&s32, uset, sizeof(*uset)))
		return -EFAULT;

	set->sig[0] = s32.sig[0] | (((long)s32.sig[1]) << 32);
	return 0;
}

/*
 * VFP save/restore code.
 *
 * We have to be careful with endianness, since the fpsimd context-switch
 * code operates on 128-bit (Q) register values whereas the compat ABI
 * uses an array of 64-bit (D) registers. Consequently, we need to swap
 * the two halves of each Q register when running on a big-endian CPU.
 */
union __fpsimd_vreg {
	__uint128_t	raw;
	struct {
#ifdef __AARCH64EB__
		u64	hi;
		u64	lo;
#else
		u64	lo;
		u64	hi;
#endif
	};
};

static int compat_preserve_vfp_context(struct compat_vfp_sigframe __user *frame)
{
	struct user_fpsimd_state const *fpsimd =
		&current->thread.uw.fpsimd_state;
	compat_ulong_t magic = VFP_MAGIC;
	compat_ulong_t size = VFP_STORAGE_SIZE;
	compat_ulong_t fpscr, fpexc;
	int i, err = 0;

	/*
	 * Save the hardware registers to the fpsimd_state structure.
	 * Note that this also saves V16-31, which aren't visible
	 * in AArch32.
	 */
	fpsimd_signal_preserve_current_state();

	/* Place structure header on the stack */
	__put_user_error(magic, &frame->magic, err);
	__put_user_error(size, &frame->size, err);

	/*
	 * Now copy the FP registers. Since the registers are packed,
	 * we can copy the prefix we want (V0-V15) as it is.
	 */
	for (i = 0; i < ARRAY_SIZE(frame->ufp.fpregs); i += 2) {
		union __fpsimd_vreg vreg = {
			.raw = fpsimd->vregs[i >> 1],
		};

		__put_user_error(vreg.lo, &frame->ufp.fpregs[i], err);
		__put_user_error(vreg.hi, &frame->ufp.fpregs[i + 1], err);
	}

	/* Create an AArch32 fpscr from the fpsr and the fpcr. */
	fpscr = (fpsimd->fpsr & VFP_FPSCR_STAT_MASK) |
		(fpsimd->fpcr & VFP_FPSCR_CTRL_MASK);
	__put_user_error(fpscr, &frame->ufp.fpscr, err);

	/*
	 * The exception register aren't available so we fake up a
	 * basic FPEXC and zero everything else.
	 */
	fpexc = (1 << 30);
	__put_user_error(fpexc, &frame->ufp_exc.fpexc, err);
	__put_user_error(0, &frame->ufp_exc.fpinst, err);
	__put_user_error(0, &frame->ufp_exc.fpinst2, err);

	return err ? -EFAULT : 0;
}

static int compat_restore_vfp_context(struct compat_vfp_sigframe __user *frame)
{
	struct user_fpsimd_state fpsimd;
	compat_ulong_t magic = VFP_MAGIC;
	compat_ulong_t size = VFP_STORAGE_SIZE;
	compat_ulong_t fpscr;
	int i, err = 0;

	__get_user_error(magic, &frame->magic, err);
	__get_user_error(size, &frame->size, err);

	if (err)
		return -EFAULT;
	if (magic != VFP_MAGIC || size != VFP_STORAGE_SIZE)
		return -EINVAL;

	/* Copy the FP registers into the start of the fpsimd_state. */
	for (i = 0; i < ARRAY_SIZE(frame->ufp.fpregs); i += 2) {
		union __fpsimd_vreg vreg;

		__get_user_error(vreg.lo, &frame->ufp.fpregs[i], err);
		__get_user_error(vreg.hi, &frame->ufp.fpregs[i + 1], err);
		fpsimd.vregs[i >> 1] = vreg.raw;
	}

	/* Extract the fpsr and the fpcr from the fpscr */
	__get_user_error(fpscr, &frame->ufp.fpscr, err);
	fpsimd.fpsr = fpscr & VFP_FPSCR_STAT_MASK;
	fpsimd.fpcr = fpscr & VFP_FPSCR_CTRL_MASK;

	/*
	 * We don't need to touch the exception register, so
	 * reload the hardware state.
	 */
	if (!err)
		fpsimd_update_current_state(&fpsimd);

	return err ? -EFAULT : 0;
}

static int compat_restore_sigframe(struct pt_regs *regs,
				   struct compat_sigframe __user *sf)
{
	int err;
	sigset_t set;
	struct compat_aux_sigframe __user *aux;
	unsigned long psr;

	err = get_sigset_t(&set, &sf->uc.uc_sigmask);
	if (err == 0) {
		sigdelsetmask(&set, ~_BLOCKABLE);
		set_current_blocked(&set);
	}

	__get_user_error(regs->regs[0], &sf->uc.uc_mcontext.arm_r0, err);
	__get_user_error(regs->regs[1], &sf->uc.uc_mcontext.arm_r1, err);
	__get_user_error(regs->regs[2], &sf->uc.uc_mcontext.arm_r2, err);
	__get_user_error(regs->regs[3], &sf->uc.uc_mcontext.arm_r3, err);
	__get_user_error(regs->regs[4], &sf->uc.uc_mcontext.arm_r4, err);
	__get_user_error(regs->regs[5], &sf->uc.uc_mcontext.arm_r5, err);
	__get_user_error(regs->regs[6], &sf->uc.uc_mcontext.arm_r6, err);
	__get_user_error(regs->regs[7], &sf->uc.uc_mcontext.arm_r7, err);
	__get_user_error(regs->regs[8], &sf->uc.uc_mcontext.arm_r8, err);
	__get_user_error(regs->regs[9], &sf->uc.uc_mcontext.arm_r9, err);
	__get_user_error(regs->regs[10], &sf->uc.uc_mcontext.arm_r10, err);
	__get_user_error(regs->regs[11], &sf->uc.uc_mcontext.arm_fp, err);
	__get_user_error(regs->regs[12], &sf->uc.uc_mcontext.arm_ip, err);
	__get_user_error(regs->compat_sp, &sf->uc.uc_mcontext.arm_sp, err);
	__get_user_error(regs->compat_lr, &sf->uc.uc_mcontext.arm_lr, err);
	__get_user_error(regs->pc, &sf->uc.uc_mcontext.arm_pc, err);
	__get_user_error(psr, &sf->uc.uc_mcontext.arm_cpsr, err);

	regs->pstate = compat_psr_to_pstate(psr);

	/*
	 * Avoid compat_sys_sigreturn() restarting.
	 */
	forget_syscall(regs);

	err |= !valid_user_regs(&regs->user_regs, current);

	aux = (struct compat_aux_sigframe __user *) sf->uc.uc_regspace;
	if (err == 0)
		err |= compat_restore_vfp_context(&aux->vfp);

	return err;
}

COMPAT_SYSCALL_DEFINE0(sigreturn)
{
	struct pt_regs *regs = current_pt_regs();
	struct compat_sigframe __user *frame;

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

	/*
	 * Since we stacked the signal on a 64-bit boundary,
	 * then 'sp' should be word aligned here.  If it's
	 * not, then the user is trying to mess with us.
	 */
	if (regs->compat_sp & 7)
		goto badframe;

	frame = (struct compat_sigframe __user *)regs->compat_sp;

	if (!access_ok(frame, sizeof (*frame)))
		goto badframe;

	if (compat_restore_sigframe(regs, frame))
		goto badframe;

	return regs->regs[0];

badframe:
	arm64_notify_segfault(regs->compat_sp);
	return 0;
}

COMPAT_SYSCALL_DEFINE0(rt_sigreturn)
{
	struct pt_regs *regs = current_pt_regs();
	struct compat_rt_sigframe __user *frame;

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

	/*
	 * Since we stacked the signal on a 64-bit boundary,
	 * then 'sp' should be word aligned here.  If it's
	 * not, then the user is trying to mess with us.
	 */
	if (regs->compat_sp & 7)
		goto badframe;

	frame = (struct compat_rt_sigframe __user *)regs->compat_sp;

	if (!access_ok(frame, sizeof (*frame)))
		goto badframe;

	if (compat_restore_sigframe(regs, &frame->sig))
		goto badframe;

	if (compat_restore_altstack(&frame->sig.uc.uc_stack))
		goto badframe;

	return regs->regs[0];

badframe:
	arm64_notify_segfault(regs->compat_sp);
	return 0;
}

static void __user *compat_get_sigframe(struct ksignal *ksig,
					struct pt_regs *regs,
					int framesize)
{
	compat_ulong_t sp = sigsp(regs->compat_sp, ksig);
	void __user *frame;

	/*
	 * ATPCS B01 mandates 8-byte alignment
	 */
	frame = compat_ptr((compat_uptr_t)((sp - framesize) & ~7));

	/*
	 * Check that we can actually write to the signal frame.
	 */
	if (!access_ok(frame, framesize))
		frame = NULL;

	return frame;
}

static void compat_setup_return(struct pt_regs *regs, struct k_sigaction *ka,
				compat_ulong_t __user *rc, void __user *frame,
				int usig)
{
	compat_ulong_t handler = ptr_to_compat(ka->sa.sa_handler);
	compat_ulong_t retcode;
	compat_ulong_t spsr = regs->pstate & ~(PSR_f | PSR_AA32_E_BIT);
	int thumb;

	/* Check if the handler is written for ARM or Thumb */
	thumb = handler & 1;

	if (thumb)
		spsr |= PSR_AA32_T_BIT;
	else
		spsr &= ~PSR_AA32_T_BIT;

	/* The IT state must be cleared for both ARM and Thumb-2 */
	spsr &= ~PSR_AA32_IT_MASK;

	/* Restore the original endianness */
	spsr |= PSR_AA32_ENDSTATE;

	if (ka->sa.sa_flags & SA_RESTORER) {
		retcode = ptr_to_compat(ka->sa.sa_restorer);
	} else {
		/* Set up sigreturn pointer */
		unsigned int idx = thumb << 1;

		if (ka->sa.sa_flags & SA_SIGINFO)
			idx += 3;

		retcode = (unsigned long)current->mm->context.vdso +
			  (idx << 2) + thumb;
	}

	regs->regs[0]	= usig;
	regs->compat_sp	= ptr_to_compat(frame);
	regs->compat_lr	= retcode;
	regs->pc	= handler;
	regs->pstate	= spsr;
}

static int compat_setup_sigframe(struct compat_sigframe __user *sf,
				 struct pt_regs *regs, sigset_t *set)
{
	struct compat_aux_sigframe __user *aux;
	unsigned long psr = pstate_to_compat_psr(regs->pstate);
	int err = 0;

	__put_user_error(regs->regs[0], &sf->uc.uc_mcontext.arm_r0, err);
	__put_user_error(regs->regs[1], &sf->uc.uc_mcontext.arm_r1, err);
	__put_user_error(regs->regs[2], &sf->uc.uc_mcontext.arm_r2, err);
	__put_user_error(regs->regs[3], &sf->uc.uc_mcontext.arm_r3, err);
	__put_user_error(regs->regs[4], &sf->uc.uc_mcontext.arm_r4, err);
	__put_user_error(regs->regs[5], &sf->uc.uc_mcontext.arm_r5, err);
	__put_user_error(regs->regs[6], &sf->uc.uc_mcontext.arm_r6, err);
	__put_user_error(regs->regs[7], &sf->uc.uc_mcontext.arm_r7, err);
	__put_user_error(regs->regs[8], &sf->uc.uc_mcontext.arm_r8, err);
	__put_user_error(regs->regs[9], &sf->uc.uc_mcontext.arm_r9, err);
	__put_user_error(regs->regs[10], &sf->uc.uc_mcontext.arm_r10, err);
	__put_user_error(regs->regs[11], &sf->uc.uc_mcontext.arm_fp, err);
	__put_user_error(regs->regs[12], &sf->uc.uc_mcontext.arm_ip, err);
	__put_user_error(regs->compat_sp, &sf->uc.uc_mcontext.arm_sp, err);
	__put_user_error(regs->compat_lr, &sf->uc.uc_mcontext.arm_lr, err);
	__put_user_error(regs->pc, &sf->uc.uc_mcontext.arm_pc, err);
	__put_user_error(psr, &sf->uc.uc_mcontext.arm_cpsr, err);

	__put_user_error((compat_ulong_t)0, &sf->uc.uc_mcontext.trap_no, err);
	/* set the compat FSR WnR */
	__put_user_error(!!(current->thread.fault_code & ESR_ELx_WNR) <<
			 FSR_WRITE_SHIFT, &sf->uc.uc_mcontext.error_code, err);
	__put_user_error(current->thread.fault_address, &sf->uc.uc_mcontext.fault_address, err);
	__put_user_error(set->sig[0], &sf->uc.uc_mcontext.oldmask, err);

	err |= put_sigset_t(&sf->uc.uc_sigmask, set);

	aux = (struct compat_aux_sigframe __user *) sf->uc.uc_regspace;

	if (err == 0)
		err |= compat_preserve_vfp_context(&aux->vfp);
	__put_user_error(0, &aux->end_magic, err);

	return err;
}

/*
 * 32-bit signal handling routines called from signal.c
 */
int compat_setup_rt_frame(int usig, struct ksignal *ksig,
			  sigset_t *set, struct pt_regs *regs)
{
	struct compat_rt_sigframe __user *frame;
	int err = 0;

	frame = compat_get_sigframe(ksig, regs, sizeof(*frame));

	if (!frame)
		return 1;

	err |= copy_siginfo_to_user32(&frame->info, &ksig->info);

	__put_user_error(0, &frame->sig.uc.uc_flags, err);
	__put_user_error(0, &frame->sig.uc.uc_link, err);

	err |= __compat_save_altstack(&frame->sig.uc.uc_stack, regs->compat_sp);

	err |= compat_setup_sigframe(&frame->sig, regs, set);

	if (err == 0) {
		compat_setup_return(regs, &ksig->ka, frame->sig.retcode, frame, usig);
		regs->regs[1] = (compat_ulong_t)(unsigned long)&frame->info;
		regs->regs[2] = (compat_ulong_t)(unsigned long)&frame->sig.uc;
	}

	return err;
}

int compat_setup_frame(int usig, struct ksignal *ksig, sigset_t *set,
		       struct pt_regs *regs)
{
	struct compat_sigframe __user *frame;
	int err = 0;

	frame = compat_get_sigframe(ksig, regs, sizeof(*frame));

	if (!frame)
		return 1;

	__put_user_error(0x5ac3c35a, &frame->uc.uc_flags, err);

	err |= compat_setup_sigframe(frame, regs, set);
	if (err == 0)
		compat_setup_return(regs, &ksig->ka, frame->retcode, frame, usig);

	return err;
}

void compat_setup_restart_syscall(struct pt_regs *regs)
{
       regs->regs[7] = __NR_compat_restart_syscall;
}
Commit	Line	Data
caab277b	1	// SPDX-License-Identifier: GPL-2.0-only
3dd681d9 WD	2	/*
	3	* Based on arch/arm/kernel/signal.c
	4	*
	5	* Copyright (C) 1995-2009 Russell King
	6	* Copyright (C) 2012 ARM Ltd.
	7	* Modified by Will Deacon <will.deacon@arm.com>
3dd681d9 WD	8	*/
3dd681d9 WD	9
3dd681d9 WD	10	#include <linux/compat.h>
	11	#include <linux/signal.h>
	12	#include <linux/syscalls.h>
	13	#include <linux/ratelimit.h>
	14
9141300a	15	#include <asm/esr.h>
3dd681d9 WD	16	#include <asm/fpsimd.h>
3dd681d9 WD	17	#include <asm/signal32.h>
f71016a8	18	#include <asm/traps.h>
7c0f6ba6	19	#include <linux/uaccess.h>
f3e5c847	20	#include <asm/unistd.h>
3dd681d9	21
3dd681d9 WD	22	struct compat_sigcontext {
	23	/* We always set these two fields to 0 */
	24	compat_ulong_t trap_no;
	25	compat_ulong_t error_code;
	26
	27	compat_ulong_t oldmask;
	28	compat_ulong_t arm_r0;
	29	compat_ulong_t arm_r1;
	30	compat_ulong_t arm_r2;
	31	compat_ulong_t arm_r3;
	32	compat_ulong_t arm_r4;
	33	compat_ulong_t arm_r5;
	34	compat_ulong_t arm_r6;
	35	compat_ulong_t arm_r7;
	36	compat_ulong_t arm_r8;
	37	compat_ulong_t arm_r9;
	38	compat_ulong_t arm_r10;
	39	compat_ulong_t arm_fp;
	40	compat_ulong_t arm_ip;
	41	compat_ulong_t arm_sp;
	42	compat_ulong_t arm_lr;
	43	compat_ulong_t arm_pc;
	44	compat_ulong_t arm_cpsr;
	45	compat_ulong_t fault_address;
	46	};
	47
	48	struct compat_ucontext {
	49	compat_ulong_t uc_flags;
c0e01d5d	50	compat_uptr_t uc_link;
3dd681d9 WD	51	compat_stack_t uc_stack;
	52	struct compat_sigcontext uc_mcontext;
	53	compat_sigset_t uc_sigmask;
	54	int __unused[32 - (sizeof (compat_sigset_t) / sizeof (int))];
	55	compat_ulong_t uc_regspace[128] __attribute__((__aligned__(8)));
	56	};
	57
	58	struct compat_vfp_sigframe {
	59	compat_ulong_t magic;
	60	compat_ulong_t size;
	61	struct compat_user_vfp {
	62	compat_u64 fpregs[32];
	63	compat_ulong_t fpscr;
	64	} ufp;
	65	struct compat_user_vfp_exc {
	66	compat_ulong_t fpexc;
	67	compat_ulong_t fpinst;
	68	compat_ulong_t fpinst2;
	69	} ufp_exc;
	70	} __attribute__((__aligned__(8)));
	71
	72	#define VFP_MAGIC 0x56465001
	73	#define VFP_STORAGE_SIZE sizeof(struct compat_vfp_sigframe)
	74
9141300a CM	75	#define FSR_WRITE_SHIFT (11)
9141300a CM	76
3dd681d9 WD	77	struct compat_aux_sigframe {
	78	struct compat_vfp_sigframe vfp;
	79
	80	/* Something that isn't a valid magic number for any coprocessor. */
	81	unsigned long end_magic;
	82	} __attribute__((__aligned__(8)));
	83
	84	struct compat_sigframe {
	85	struct compat_ucontext uc;
	86	compat_ulong_t retcode[2];
	87	};
	88
	89	struct compat_rt_sigframe {
	90	struct compat_siginfo info;
	91	struct compat_sigframe sig;
	92	};
	93
	94	#define _BLOCKABLE (~(sigmask(SIGKILL) \| sigmask(SIGSTOP)))
	95
3dd681d9 WD	96	static inline int put_sigset_t(compat_sigset_t __user uset, sigset_t set)
	97	{
	98	compat_sigset_t cset;
	99
	100	cset.sig[0] = set->sig[0] & 0xffffffffull;
	101	cset.sig[1] = set->sig[0] >> 32;
	102
	103	return copy_to_user(uset, &cset, sizeof(*uset));
	104	}
	105
	106	static inline int get_sigset_t(sigset_t *set,
	107	const compat_sigset_t __user *uset)
	108	{
	109	compat_sigset_t s32;
	110
	111	if (copy_from_user(&s32, uset, sizeof(*uset)))
	112	return -EFAULT;
	113
	114	set->sig[0] = s32.sig[0] \| (((long)s32.sig[1]) << 32);
	115	return 0;
	116	}
	117
3dd681d9 WD	118	/*
3dd681d9 WD	119	* VFP save/restore code.
bdec97a8 WD	120	*
	121	* We have to be careful with endianness, since the fpsimd context-switch
	122	* code operates on 128-bit (Q) register values whereas the compat ABI
	123	* uses an array of 64-bit (D) registers. Consequently, we need to swap
	124	* the two halves of each Q register when running on a big-endian CPU.
3dd681d9	125	*/
bdec97a8 WD	126	union __fpsimd_vreg {
	127	__uint128_t raw;
	128	struct {
	129	#ifdef __AARCH64EB__
	130	u64 hi;
	131	u64 lo;
	132	#else
	133	u64 lo;
	134	u64 hi;
	135	#endif
	136	};
	137	};
	138
3dd681d9 WD	139	static int compat_preserve_vfp_context(struct compat_vfp_sigframe __user *frame)
3dd681d9 WD	140	{
65896545 DM	141	struct user_fpsimd_state const *fpsimd =
65896545 DM	142	&current->thread.uw.fpsimd_state;
3dd681d9 WD	143	compat_ulong_t magic = VFP_MAGIC;
	144	compat_ulong_t size = VFP_STORAGE_SIZE;
	145	compat_ulong_t fpscr, fpexc;
bdec97a8	146	int i, err = 0;
3dd681d9 WD	147
	148	/*
	149	* Save the hardware registers to the fpsimd_state structure.
	150	* Note that this also saves V16-31, which aren't visible
	151	* in AArch32.
	152	*/
8cd969d2	153	fpsimd_signal_preserve_current_state();
3dd681d9 WD	154
	155	/* Place structure header on the stack */
	156	__put_user_error(magic, &frame->magic, err);
	157	__put_user_error(size, &frame->size, err);
	158
	159	/*
	160	* Now copy the FP registers. Since the registers are packed,
	161	* we can copy the prefix we want (V0-V15) as it is.
3dd681d9	162	*/
bdec97a8 WD	163	for (i = 0; i < ARRAY_SIZE(frame->ufp.fpregs); i += 2) {
	164	union __fpsimd_vreg vreg = {
	165	.raw = fpsimd->vregs[i >> 1],
	166	};
	167
	168	__put_user_error(vreg.lo, &frame->ufp.fpregs[i], err);
	169	__put_user_error(vreg.hi, &frame->ufp.fpregs[i + 1], err);
	170	}
3dd681d9 WD	171
	172	/* Create an AArch32 fpscr from the fpsr and the fpcr. */
	173	fpscr = (fpsimd->fpsr & VFP_FPSCR_STAT_MASK) \|
	174	(fpsimd->fpcr & VFP_FPSCR_CTRL_MASK);
	175	__put_user_error(fpscr, &frame->ufp.fpscr, err);
	176
	177	/*
	178	* The exception register aren't available so we fake up a
	179	* basic FPEXC and zero everything else.
	180	*/
	181	fpexc = (1 << 30);
	182	__put_user_error(fpexc, &frame->ufp_exc.fpexc, err);
	183	__put_user_error(0, &frame->ufp_exc.fpinst, err);
	184	__put_user_error(0, &frame->ufp_exc.fpinst2, err);
	185
	186	return err ? -EFAULT : 0;
	187	}
	188
	189	static int compat_restore_vfp_context(struct compat_vfp_sigframe __user *frame)
	190	{
0abdeff5	191	struct user_fpsimd_state fpsimd;
3dd681d9 WD	192	compat_ulong_t magic = VFP_MAGIC;
	193	compat_ulong_t size = VFP_STORAGE_SIZE;
	194	compat_ulong_t fpscr;
bdec97a8	195	int i, err = 0;
3dd681d9 WD	196
	197	__get_user_error(magic, &frame->magic, err);
	198	__get_user_error(size, &frame->size, err);
	199
	200	if (err)
	201	return -EFAULT;
	202	if (magic != VFP_MAGIC \|\| size != VFP_STORAGE_SIZE)
	203	return -EINVAL;
	204
bdec97a8 WD	205	/* Copy the FP registers into the start of the fpsimd_state. */
	206	for (i = 0; i < ARRAY_SIZE(frame->ufp.fpregs); i += 2) {
	207	union __fpsimd_vreg vreg;
	208
	209	__get_user_error(vreg.lo, &frame->ufp.fpregs[i], err);
	210	__get_user_error(vreg.hi, &frame->ufp.fpregs[i + 1], err);
	211	fpsimd.vregs[i >> 1] = vreg.raw;
	212	}
3dd681d9 WD	213
	214	/* Extract the fpsr and the fpcr from the fpscr */
	215	__get_user_error(fpscr, &frame->ufp.fpscr, err);
	216	fpsimd.fpsr = fpscr & VFP_FPSCR_STAT_MASK;
	217	fpsimd.fpcr = fpscr & VFP_FPSCR_CTRL_MASK;
	218
	219	/*
	220	* We don't need to touch the exception register, so
	221	* reload the hardware state.
	222	*/
c51f9269 AB	223	if (!err)
c51f9269 AB	224	fpsimd_update_current_state(&fpsimd);
3dd681d9 WD	225
	226	return err ? -EFAULT : 0;
	227	}
	228
3dd681d9 WD	229	static int compat_restore_sigframe(struct pt_regs *regs,
	230	struct compat_sigframe __user *sf)
	231	{
	232	int err;
	233	sigset_t set;
	234	struct compat_aux_sigframe __user *aux;
25dc2c80	235	unsigned long psr;
3dd681d9 WD	236
	237	err = get_sigset_t(&set, &sf->uc.uc_sigmask);
	238	if (err == 0) {
	239	sigdelsetmask(&set, ~_BLOCKABLE);
	240	set_current_blocked(&set);
	241	}
	242
	243	__get_user_error(regs->regs[0], &sf->uc.uc_mcontext.arm_r0, err);
	244	__get_user_error(regs->regs[1], &sf->uc.uc_mcontext.arm_r1, err);
	245	__get_user_error(regs->regs[2], &sf->uc.uc_mcontext.arm_r2, err);
	246	__get_user_error(regs->regs[3], &sf->uc.uc_mcontext.arm_r3, err);
	247	__get_user_error(regs->regs[4], &sf->uc.uc_mcontext.arm_r4, err);
	248	__get_user_error(regs->regs[5], &sf->uc.uc_mcontext.arm_r5, err);
	249	__get_user_error(regs->regs[6], &sf->uc.uc_mcontext.arm_r6, err);
	250	__get_user_error(regs->regs[7], &sf->uc.uc_mcontext.arm_r7, err);
	251	__get_user_error(regs->regs[8], &sf->uc.uc_mcontext.arm_r8, err);
	252	__get_user_error(regs->regs[9], &sf->uc.uc_mcontext.arm_r9, err);
	253	__get_user_error(regs->regs[10], &sf->uc.uc_mcontext.arm_r10, err);
	254	__get_user_error(regs->regs[11], &sf->uc.uc_mcontext.arm_fp, err);
	255	__get_user_error(regs->regs[12], &sf->uc.uc_mcontext.arm_ip, err);
	256	__get_user_error(regs->compat_sp, &sf->uc.uc_mcontext.arm_sp, err);
	257	__get_user_error(regs->compat_lr, &sf->uc.uc_mcontext.arm_lr, err);
	258	__get_user_error(regs->pc, &sf->uc.uc_mcontext.arm_pc, err);
25dc2c80 MR	259	__get_user_error(psr, &sf->uc.uc_mcontext.arm_cpsr, err);
	260
	261	regs->pstate = compat_psr_to_pstate(psr);
3dd681d9 WD	262
	263	/*
	264	* Avoid compat_sys_sigreturn() restarting.
	265	*/
17c28958	266	forget_syscall(regs);
3dd681d9	267
dbd4d7ca	268	err \|= !valid_user_regs(&regs->user_regs, current);
3dd681d9 WD	269
	270	aux = (struct compat_aux_sigframe __user *) sf->uc.uc_regspace;
	271	if (err == 0)
	272	err \|= compat_restore_vfp_context(&aux->vfp);
	273
	274	return err;
	275	}
	276
bf4ce5cc	277	COMPAT_SYSCALL_DEFINE0(sigreturn)
3dd681d9	278	{
3085e164	279	struct pt_regs *regs = current_pt_regs();
3dd681d9 WD	280	struct compat_sigframe __user *frame;
	281
	282	/* Always make any pending restarted system calls return -EINTR */
f56141e3	283	current->restart_block.fn = do_no_restart_syscall;
3dd681d9 WD	284
	285	/*
	286	* Since we stacked the signal on a 64-bit boundary,
	287	* then 'sp' should be word aligned here. If it's
	288	* not, then the user is trying to mess with us.
	289	*/
	290	if (regs->compat_sp & 7)
	291	goto badframe;
	292
	293	frame = (struct compat_sigframe __user *)regs->compat_sp;
	294
96d4f267	295	if (!access_ok(frame, sizeof (*frame)))
3dd681d9 WD	296	goto badframe;
	297
	298	if (compat_restore_sigframe(regs, frame))
	299	goto badframe;
	300
	301	return regs->regs[0];
	302
	303	badframe:
f71016a8	304	arm64_notify_segfault(regs->compat_sp);
3dd681d9 WD	305	return 0;
	306	}
	307
bf4ce5cc	308	COMPAT_SYSCALL_DEFINE0(rt_sigreturn)
3dd681d9	309	{
3085e164	310	struct pt_regs *regs = current_pt_regs();
3dd681d9 WD	311	struct compat_rt_sigframe __user *frame;
	312
	313	/* Always make any pending restarted system calls return -EINTR */
f56141e3	314	current->restart_block.fn = do_no_restart_syscall;
3dd681d9 WD	315
	316	/*
	317	* Since we stacked the signal on a 64-bit boundary,
	318	* then 'sp' should be word aligned here. If it's
	319	* not, then the user is trying to mess with us.
	320	*/
	321	if (regs->compat_sp & 7)
	322	goto badframe;
	323
	324	frame = (struct compat_rt_sigframe __user *)regs->compat_sp;
	325
96d4f267	326	if (!access_ok(frame, sizeof (*frame)))
3dd681d9 WD	327	goto badframe;
	328
	329	if (compat_restore_sigframe(regs, &frame->sig))
	330	goto badframe;
	331
207bdae4	332	if (compat_restore_altstack(&frame->sig.uc.uc_stack))
3dd681d9 WD	333	goto badframe;
	334
	335	return regs->regs[0];
	336
	337	badframe:
f71016a8	338	arm64_notify_segfault(regs->compat_sp);
3dd681d9 WD	339	return 0;
	340	}
	341
38a7be3c	342	static void __user compat_get_sigframe(struct ksignal ksig,
88a24cff WD	343	struct pt_regs *regs,
88a24cff WD	344	int framesize)
3dd681d9	345	{
38a7be3c	346	compat_ulong_t sp = sigsp(regs->compat_sp, ksig);
3dd681d9 WD	347	void __user *frame;
3dd681d9 WD	348
3dd681d9 WD	349	/*
	350	* ATPCS B01 mandates 8-byte alignment
	351	*/
	352	frame = compat_ptr((compat_uptr_t)((sp - framesize) & ~7));
	353
	354	/*
	355	* Check that we can actually write to the signal frame.
	356	*/
96d4f267	357	if (!access_ok(frame, framesize))
3dd681d9 WD	358	frame = NULL;
	359
	360	return frame;
	361	}
	362
060a18c7 WD	363	static void compat_setup_return(struct pt_regs regs, struct k_sigaction ka,
	364	compat_ulong_t __user rc, void __user frame,
	365	int usig)
3dd681d9 WD	366	{
	367	compat_ulong_t handler = ptr_to_compat(ka->sa.sa_handler);
	368	compat_ulong_t retcode;
d64567f6	369	compat_ulong_t spsr = regs->pstate & ~(PSR_f \| PSR_AA32_E_BIT);
3dd681d9 WD	370	int thumb;
	371
	372	/* Check if the handler is written for ARM or Thumb */
	373	thumb = handler & 1;
	374
aa62c209	375	if (thumb)
d64567f6	376	spsr \|= PSR_AA32_T_BIT;
aa62c209	377	else
d64567f6	378	spsr &= ~PSR_AA32_T_BIT;
aa62c209 P	379
aa62c209 P	380	/* The IT state must be cleared for both ARM and Thumb-2 */
d64567f6	381	spsr &= ~PSR_AA32_IT_MASK;
3dd681d9	382
2d888f48	383	/* Restore the original endianness */
d64567f6	384	spsr \|= PSR_AA32_ENDSTATE;
2d888f48	385
3dd681d9 WD	386	if (ka->sa.sa_flags & SA_RESTORER) {
	387	retcode = ptr_to_compat(ka->sa.sa_restorer);
	388	} else {
	389	/* Set up sigreturn pointer */
	390	unsigned int idx = thumb << 1;
	391
	392	if (ka->sa.sa_flags & SA_SIGINFO)
	393	idx += 3;
	394
0d747f65	395	retcode = (unsigned long)current->mm->context.vdso +
3dd681d9 WD	396	(idx << 2) + thumb;
	397	}
	398
	399	regs->regs[0] = usig;
	400	regs->compat_sp = ptr_to_compat(frame);
	401	regs->compat_lr = retcode;
	402	regs->pc = handler;
	403	regs->pstate = spsr;
3dd681d9 WD	404	}
	405
	406	static int compat_setup_sigframe(struct compat_sigframe __user *sf,
	407	struct pt_regs regs, sigset_t set)
	408	{
	409	struct compat_aux_sigframe __user *aux;
25dc2c80	410	unsigned long psr = pstate_to_compat_psr(regs->pstate);
3dd681d9 WD	411	int err = 0;
	412
	413	__put_user_error(regs->regs[0], &sf->uc.uc_mcontext.arm_r0, err);
	414	__put_user_error(regs->regs[1], &sf->uc.uc_mcontext.arm_r1, err);
	415	__put_user_error(regs->regs[2], &sf->uc.uc_mcontext.arm_r2, err);
	416	__put_user_error(regs->regs[3], &sf->uc.uc_mcontext.arm_r3, err);
	417	__put_user_error(regs->regs[4], &sf->uc.uc_mcontext.arm_r4, err);
	418	__put_user_error(regs->regs[5], &sf->uc.uc_mcontext.arm_r5, err);
	419	__put_user_error(regs->regs[6], &sf->uc.uc_mcontext.arm_r6, err);
	420	__put_user_error(regs->regs[7], &sf->uc.uc_mcontext.arm_r7, err);
	421	__put_user_error(regs->regs[8], &sf->uc.uc_mcontext.arm_r8, err);
	422	__put_user_error(regs->regs[9], &sf->uc.uc_mcontext.arm_r9, err);
	423	__put_user_error(regs->regs[10], &sf->uc.uc_mcontext.arm_r10, err);
	424	__put_user_error(regs->regs[11], &sf->uc.uc_mcontext.arm_fp, err);
	425	__put_user_error(regs->regs[12], &sf->uc.uc_mcontext.arm_ip, err);
	426	__put_user_error(regs->compat_sp, &sf->uc.uc_mcontext.arm_sp, err);
	427	__put_user_error(regs->compat_lr, &sf->uc.uc_mcontext.arm_lr, err);
	428	__put_user_error(regs->pc, &sf->uc.uc_mcontext.arm_pc, err);
25dc2c80	429	__put_user_error(psr, &sf->uc.uc_mcontext.arm_cpsr, err);
3dd681d9 WD	430
3dd681d9 WD	431	__put_user_error((compat_ulong_t)0, &sf->uc.uc_mcontext.trap_no, err);
9141300a	432	/* set the compat FSR WnR */
aed40e01	433	__put_user_error(!!(current->thread.fault_code & ESR_ELx_WNR) <<
9141300a	434	FSR_WRITE_SHIFT, &sf->uc.uc_mcontext.error_code, err);
3dd681d9 WD	435	__put_user_error(current->thread.fault_address, &sf->uc.uc_mcontext.fault_address, err);
	436	__put_user_error(set->sig[0], &sf->uc.uc_mcontext.oldmask, err);
	437
	438	err \|= put_sigset_t(&sf->uc.uc_sigmask, set);
	439
	440	aux = (struct compat_aux_sigframe __user *) sf->uc.uc_regspace;
	441
	442	if (err == 0)
	443	err \|= compat_preserve_vfp_context(&aux->vfp);
	444	__put_user_error(0, &aux->end_magic, err);
	445
	446	return err;
	447	}
	448
	449	/*
	450	* 32-bit signal handling routines called from signal.c
	451	*/
00554fa4	452	int compat_setup_rt_frame(int usig, struct ksignal *ksig,
3dd681d9 WD	453	sigset_t set, struct pt_regs regs)
	454	{
	455	struct compat_rt_sigframe __user *frame;
3dd681d9 WD	456	int err = 0;
3dd681d9 WD	457
38a7be3c	458	frame = compat_get_sigframe(ksig, regs, sizeof(*frame));
3dd681d9 WD	459
	460	if (!frame)
	461	return 1;
	462
00554fa4	463	err \|= copy_siginfo_to_user32(&frame->info, &ksig->info);
3dd681d9 WD	464
3dd681d9 WD	465	__put_user_error(0, &frame->sig.uc.uc_flags, err);
c0e01d5d	466	__put_user_error(0, &frame->sig.uc.uc_link, err);
3dd681d9	467
207bdae4	468	err \|= __compat_save_altstack(&frame->sig.uc.uc_stack, regs->compat_sp);
3dd681d9 WD	469
3dd681d9 WD	470	err \|= compat_setup_sigframe(&frame->sig, regs, set);
3dd681d9 WD	471
3dd681d9 WD	472	if (err == 0) {
00554fa4	473	compat_setup_return(regs, &ksig->ka, frame->sig.retcode, frame, usig);
3dd681d9 WD	474	regs->regs[1] = (compat_ulong_t)(unsigned long)&frame->info;
	475	regs->regs[2] = (compat_ulong_t)(unsigned long)&frame->sig.uc;
	476	}
	477
	478	return err;
	479	}
	480
00554fa4	481	int compat_setup_frame(int usig, struct ksignal ksig, sigset_t set,
3dd681d9 WD	482	struct pt_regs *regs)
	483	{
	484	struct compat_sigframe __user *frame;
	485	int err = 0;
	486
38a7be3c	487	frame = compat_get_sigframe(ksig, regs, sizeof(*frame));
3dd681d9 WD	488
	489	if (!frame)
	490	return 1;
	491
	492	__put_user_error(0x5ac3c35a, &frame->uc.uc_flags, err);
	493
	494	err \|= compat_setup_sigframe(frame, regs, set);
	495	if (err == 0)
00554fa4	496	compat_setup_return(regs, &ksig->ka, frame->retcode, frame, usig);
3dd681d9 WD	497
	498	return err;
	499	}
	500
3dd681d9 WD	501	void compat_setup_restart_syscall(struct pt_regs *regs)
3dd681d9 WD	502	{
4ed27ecf	503	regs->regs[7] = __NR_compat_restart_syscall;
3dd681d9	504	}