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

/*
 * 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>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

#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
3dd681d9 WD	1	/*
	2	* Based on arch/arm/kernel/signal.c
	3	*
	4	* Copyright (C) 1995-2009 Russell King
	5	* Copyright (C) 2012 ARM Ltd.
	6	* Modified by Will Deacon <will.deacon@arm.com>
	7	*
	8	* This program is free software; you can redistribute it and/or modify
	9	* it under the terms of the GNU General Public License version 2 as
	10	* published by the Free Software Foundation.
	11	*
	12	* This program is distributed in the hope that it will be useful,
	13	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	14	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	15	* GNU General Public License for more details.
	16	*
	17	* You should have received a copy of the GNU General Public License
	18	* along with this program. If not, see <http://www.gnu.org/licenses/>.
	19	*/
	20
3dd681d9 WD	21	#include <linux/compat.h>
	22	#include <linux/signal.h>
	23	#include <linux/syscalls.h>
	24	#include <linux/ratelimit.h>
	25
9141300a	26	#include <asm/esr.h>
3dd681d9 WD	27	#include <asm/fpsimd.h>
3dd681d9 WD	28	#include <asm/signal32.h>
f71016a8	29	#include <asm/traps.h>
7c0f6ba6	30	#include <linux/uaccess.h>
f3e5c847	31	#include <asm/unistd.h>
3dd681d9	32
3dd681d9 WD	33	struct compat_sigcontext {
	34	/* We always set these two fields to 0 */
	35	compat_ulong_t trap_no;
	36	compat_ulong_t error_code;
	37
	38	compat_ulong_t oldmask;
	39	compat_ulong_t arm_r0;
	40	compat_ulong_t arm_r1;
	41	compat_ulong_t arm_r2;
	42	compat_ulong_t arm_r3;
	43	compat_ulong_t arm_r4;
	44	compat_ulong_t arm_r5;
	45	compat_ulong_t arm_r6;
	46	compat_ulong_t arm_r7;
	47	compat_ulong_t arm_r8;
	48	compat_ulong_t arm_r9;
	49	compat_ulong_t arm_r10;
	50	compat_ulong_t arm_fp;
	51	compat_ulong_t arm_ip;
	52	compat_ulong_t arm_sp;
	53	compat_ulong_t arm_lr;
	54	compat_ulong_t arm_pc;
	55	compat_ulong_t arm_cpsr;
	56	compat_ulong_t fault_address;
	57	};
	58
	59	struct compat_ucontext {
	60	compat_ulong_t uc_flags;
c0e01d5d	61	compat_uptr_t uc_link;
3dd681d9 WD	62	compat_stack_t uc_stack;
	63	struct compat_sigcontext uc_mcontext;
	64	compat_sigset_t uc_sigmask;
	65	int __unused[32 - (sizeof (compat_sigset_t) / sizeof (int))];
	66	compat_ulong_t uc_regspace[128] __attribute__((__aligned__(8)));
	67	};
	68
	69	struct compat_vfp_sigframe {
	70	compat_ulong_t magic;
	71	compat_ulong_t size;
	72	struct compat_user_vfp {
	73	compat_u64 fpregs[32];
	74	compat_ulong_t fpscr;
	75	} ufp;
	76	struct compat_user_vfp_exc {
	77	compat_ulong_t fpexc;
	78	compat_ulong_t fpinst;
	79	compat_ulong_t fpinst2;
	80	} ufp_exc;
	81	} __attribute__((__aligned__(8)));
	82
	83	#define VFP_MAGIC 0x56465001
	84	#define VFP_STORAGE_SIZE sizeof(struct compat_vfp_sigframe)
	85
9141300a CM	86	#define FSR_WRITE_SHIFT (11)
9141300a CM	87
3dd681d9 WD	88	struct compat_aux_sigframe {
	89	struct compat_vfp_sigframe vfp;
	90
	91	/* Something that isn't a valid magic number for any coprocessor. */
	92	unsigned long end_magic;
	93	} __attribute__((__aligned__(8)));
	94
	95	struct compat_sigframe {
	96	struct compat_ucontext uc;
	97	compat_ulong_t retcode[2];
	98	};
	99
	100	struct compat_rt_sigframe {
	101	struct compat_siginfo info;
	102	struct compat_sigframe sig;
	103	};
	104
	105	#define _BLOCKABLE (~(sigmask(SIGKILL) \| sigmask(SIGSTOP)))
	106
3dd681d9 WD	107	static inline int put_sigset_t(compat_sigset_t __user uset, sigset_t set)
	108	{
	109	compat_sigset_t cset;
	110
	111	cset.sig[0] = set->sig[0] & 0xffffffffull;
	112	cset.sig[1] = set->sig[0] >> 32;
	113
	114	return copy_to_user(uset, &cset, sizeof(*uset));
	115	}
	116
	117	static inline int get_sigset_t(sigset_t *set,
	118	const compat_sigset_t __user *uset)
	119	{
	120	compat_sigset_t s32;
	121
	122	if (copy_from_user(&s32, uset, sizeof(*uset)))
	123	return -EFAULT;
	124
	125	set->sig[0] = s32.sig[0] \| (((long)s32.sig[1]) << 32);
	126	return 0;
	127	}
	128
3dd681d9 WD	129	/*
3dd681d9 WD	130	* VFP save/restore code.
bdec97a8 WD	131	*
	132	* We have to be careful with endianness, since the fpsimd context-switch
	133	* code operates on 128-bit (Q) register values whereas the compat ABI
	134	* uses an array of 64-bit (D) registers. Consequently, we need to swap
	135	* the two halves of each Q register when running on a big-endian CPU.
3dd681d9	136	*/
bdec97a8 WD	137	union __fpsimd_vreg {
	138	__uint128_t raw;
	139	struct {
	140	#ifdef __AARCH64EB__
	141	u64 hi;
	142	u64 lo;
	143	#else
	144	u64 lo;
	145	u64 hi;
	146	#endif
	147	};
	148	};
	149
3dd681d9 WD	150	static int compat_preserve_vfp_context(struct compat_vfp_sigframe __user *frame)
3dd681d9 WD	151	{
65896545 DM	152	struct user_fpsimd_state const *fpsimd =
65896545 DM	153	&current->thread.uw.fpsimd_state;
3dd681d9 WD	154	compat_ulong_t magic = VFP_MAGIC;
	155	compat_ulong_t size = VFP_STORAGE_SIZE;
	156	compat_ulong_t fpscr, fpexc;
bdec97a8	157	int i, err = 0;
3dd681d9 WD	158
	159	/*
	160	* Save the hardware registers to the fpsimd_state structure.
	161	* Note that this also saves V16-31, which aren't visible
	162	* in AArch32.
	163	*/
8cd969d2	164	fpsimd_signal_preserve_current_state();
3dd681d9 WD	165
	166	/* Place structure header on the stack */
	167	__put_user_error(magic, &frame->magic, err);
	168	__put_user_error(size, &frame->size, err);
	169
	170	/*
	171	* Now copy the FP registers. Since the registers are packed,
	172	* we can copy the prefix we want (V0-V15) as it is.
3dd681d9	173	*/
bdec97a8 WD	174	for (i = 0; i < ARRAY_SIZE(frame->ufp.fpregs); i += 2) {
	175	union __fpsimd_vreg vreg = {
	176	.raw = fpsimd->vregs[i >> 1],
	177	};
	178
	179	__put_user_error(vreg.lo, &frame->ufp.fpregs[i], err);
	180	__put_user_error(vreg.hi, &frame->ufp.fpregs[i + 1], err);
	181	}
3dd681d9 WD	182
	183	/* Create an AArch32 fpscr from the fpsr and the fpcr. */
	184	fpscr = (fpsimd->fpsr & VFP_FPSCR_STAT_MASK) \|
	185	(fpsimd->fpcr & VFP_FPSCR_CTRL_MASK);
	186	__put_user_error(fpscr, &frame->ufp.fpscr, err);
	187
	188	/*
	189	* The exception register aren't available so we fake up a
	190	* basic FPEXC and zero everything else.
	191	*/
	192	fpexc = (1 << 30);
	193	__put_user_error(fpexc, &frame->ufp_exc.fpexc, err);
	194	__put_user_error(0, &frame->ufp_exc.fpinst, err);
	195	__put_user_error(0, &frame->ufp_exc.fpinst2, err);
	196
	197	return err ? -EFAULT : 0;
	198	}
	199
	200	static int compat_restore_vfp_context(struct compat_vfp_sigframe __user *frame)
	201	{
0abdeff5	202	struct user_fpsimd_state fpsimd;
3dd681d9 WD	203	compat_ulong_t magic = VFP_MAGIC;
	204	compat_ulong_t size = VFP_STORAGE_SIZE;
	205	compat_ulong_t fpscr;
bdec97a8	206	int i, err = 0;
3dd681d9 WD	207
	208	__get_user_error(magic, &frame->magic, err);
	209	__get_user_error(size, &frame->size, err);
	210
	211	if (err)
	212	return -EFAULT;
	213	if (magic != VFP_MAGIC \|\| size != VFP_STORAGE_SIZE)
	214	return -EINVAL;
	215
bdec97a8 WD	216	/* Copy the FP registers into the start of the fpsimd_state. */
	217	for (i = 0; i < ARRAY_SIZE(frame->ufp.fpregs); i += 2) {
	218	union __fpsimd_vreg vreg;
	219
	220	__get_user_error(vreg.lo, &frame->ufp.fpregs[i], err);
	221	__get_user_error(vreg.hi, &frame->ufp.fpregs[i + 1], err);
	222	fpsimd.vregs[i >> 1] = vreg.raw;
	223	}
3dd681d9 WD	224
	225	/* Extract the fpsr and the fpcr from the fpscr */
	226	__get_user_error(fpscr, &frame->ufp.fpscr, err);
	227	fpsimd.fpsr = fpscr & VFP_FPSCR_STAT_MASK;
	228	fpsimd.fpcr = fpscr & VFP_FPSCR_CTRL_MASK;
	229
	230	/*
	231	* We don't need to touch the exception register, so
	232	* reload the hardware state.
	233	*/
c51f9269 AB	234	if (!err)
c51f9269 AB	235	fpsimd_update_current_state(&fpsimd);
3dd681d9 WD	236
	237	return err ? -EFAULT : 0;
	238	}
	239
3dd681d9 WD	240	static int compat_restore_sigframe(struct pt_regs *regs,
	241	struct compat_sigframe __user *sf)
	242	{
	243	int err;
	244	sigset_t set;
	245	struct compat_aux_sigframe __user *aux;
25dc2c80	246	unsigned long psr;
3dd681d9 WD	247
	248	err = get_sigset_t(&set, &sf->uc.uc_sigmask);
	249	if (err == 0) {
	250	sigdelsetmask(&set, ~_BLOCKABLE);
	251	set_current_blocked(&set);
	252	}
	253
	254	__get_user_error(regs->regs[0], &sf->uc.uc_mcontext.arm_r0, err);
	255	__get_user_error(regs->regs[1], &sf->uc.uc_mcontext.arm_r1, err);
	256	__get_user_error(regs->regs[2], &sf->uc.uc_mcontext.arm_r2, err);
	257	__get_user_error(regs->regs[3], &sf->uc.uc_mcontext.arm_r3, err);
	258	__get_user_error(regs->regs[4], &sf->uc.uc_mcontext.arm_r4, err);
	259	__get_user_error(regs->regs[5], &sf->uc.uc_mcontext.arm_r5, err);
	260	__get_user_error(regs->regs[6], &sf->uc.uc_mcontext.arm_r6, err);
	261	__get_user_error(regs->regs[7], &sf->uc.uc_mcontext.arm_r7, err);
	262	__get_user_error(regs->regs[8], &sf->uc.uc_mcontext.arm_r8, err);
	263	__get_user_error(regs->regs[9], &sf->uc.uc_mcontext.arm_r9, err);
	264	__get_user_error(regs->regs[10], &sf->uc.uc_mcontext.arm_r10, err);
	265	__get_user_error(regs->regs[11], &sf->uc.uc_mcontext.arm_fp, err);
	266	__get_user_error(regs->regs[12], &sf->uc.uc_mcontext.arm_ip, err);
	267	__get_user_error(regs->compat_sp, &sf->uc.uc_mcontext.arm_sp, err);
	268	__get_user_error(regs->compat_lr, &sf->uc.uc_mcontext.arm_lr, err);
	269	__get_user_error(regs->pc, &sf->uc.uc_mcontext.arm_pc, err);
25dc2c80 MR	270	__get_user_error(psr, &sf->uc.uc_mcontext.arm_cpsr, err);
	271
	272	regs->pstate = compat_psr_to_pstate(psr);
3dd681d9 WD	273
	274	/*
	275	* Avoid compat_sys_sigreturn() restarting.
	276	*/
17c28958	277	forget_syscall(regs);
3dd681d9	278
dbd4d7ca	279	err \|= !valid_user_regs(&regs->user_regs, current);
3dd681d9 WD	280
	281	aux = (struct compat_aux_sigframe __user *) sf->uc.uc_regspace;
	282	if (err == 0)
	283	err \|= compat_restore_vfp_context(&aux->vfp);
	284
	285	return err;
	286	}
	287
bf4ce5cc	288	COMPAT_SYSCALL_DEFINE0(sigreturn)
3dd681d9	289	{
3085e164	290	struct pt_regs *regs = current_pt_regs();
3dd681d9 WD	291	struct compat_sigframe __user *frame;
	292
	293	/* Always make any pending restarted system calls return -EINTR */
f56141e3	294	current->restart_block.fn = do_no_restart_syscall;
3dd681d9 WD	295
	296	/*
	297	* Since we stacked the signal on a 64-bit boundary,
	298	* then 'sp' should be word aligned here. If it's
	299	* not, then the user is trying to mess with us.
	300	*/
	301	if (regs->compat_sp & 7)
	302	goto badframe;
	303
	304	frame = (struct compat_sigframe __user *)regs->compat_sp;
	305
96d4f267	306	if (!access_ok(frame, sizeof (*frame)))
3dd681d9 WD	307	goto badframe;
	308
	309	if (compat_restore_sigframe(regs, frame))
	310	goto badframe;
	311
	312	return regs->regs[0];
	313
	314	badframe:
f71016a8	315	arm64_notify_segfault(regs->compat_sp);
3dd681d9 WD	316	return 0;
	317	}
	318
bf4ce5cc	319	COMPAT_SYSCALL_DEFINE0(rt_sigreturn)
3dd681d9	320	{
3085e164	321	struct pt_regs *regs = current_pt_regs();
3dd681d9 WD	322	struct compat_rt_sigframe __user *frame;
	323
	324	/* Always make any pending restarted system calls return -EINTR */
f56141e3	325	current->restart_block.fn = do_no_restart_syscall;
3dd681d9 WD	326
	327	/*
	328	* Since we stacked the signal on a 64-bit boundary,
	329	* then 'sp' should be word aligned here. If it's
	330	* not, then the user is trying to mess with us.
	331	*/
	332	if (regs->compat_sp & 7)
	333	goto badframe;
	334
	335	frame = (struct compat_rt_sigframe __user *)regs->compat_sp;
	336
96d4f267	337	if (!access_ok(frame, sizeof (*frame)))
3dd681d9 WD	338	goto badframe;
	339
	340	if (compat_restore_sigframe(regs, &frame->sig))
	341	goto badframe;
	342
207bdae4	343	if (compat_restore_altstack(&frame->sig.uc.uc_stack))
3dd681d9 WD	344	goto badframe;
	345
	346	return regs->regs[0];
	347
	348	badframe:
f71016a8	349	arm64_notify_segfault(regs->compat_sp);
3dd681d9 WD	350	return 0;
	351	}
	352
38a7be3c	353	static void __user compat_get_sigframe(struct ksignal ksig,
88a24cff WD	354	struct pt_regs *regs,
88a24cff WD	355	int framesize)
3dd681d9	356	{
38a7be3c	357	compat_ulong_t sp = sigsp(regs->compat_sp, ksig);
3dd681d9 WD	358	void __user *frame;
3dd681d9 WD	359
3dd681d9 WD	360	/*
	361	* ATPCS B01 mandates 8-byte alignment
	362	*/
	363	frame = compat_ptr((compat_uptr_t)((sp - framesize) & ~7));
	364
	365	/*
	366	* Check that we can actually write to the signal frame.
	367	*/
96d4f267	368	if (!access_ok(frame, framesize))
3dd681d9 WD	369	frame = NULL;
	370
	371	return frame;
	372	}
	373
060a18c7 WD	374	static void compat_setup_return(struct pt_regs regs, struct k_sigaction ka,
	375	compat_ulong_t __user rc, void __user frame,
	376	int usig)
3dd681d9 WD	377	{
	378	compat_ulong_t handler = ptr_to_compat(ka->sa.sa_handler);
	379	compat_ulong_t retcode;
d64567f6	380	compat_ulong_t spsr = regs->pstate & ~(PSR_f \| PSR_AA32_E_BIT);
3dd681d9 WD	381	int thumb;
	382
	383	/* Check if the handler is written for ARM or Thumb */
	384	thumb = handler & 1;
	385
aa62c209	386	if (thumb)
d64567f6	387	spsr \|= PSR_AA32_T_BIT;
aa62c209	388	else
d64567f6	389	spsr &= ~PSR_AA32_T_BIT;
aa62c209 P	390
aa62c209 P	391	/* The IT state must be cleared for both ARM and Thumb-2 */
d64567f6	392	spsr &= ~PSR_AA32_IT_MASK;
3dd681d9	393
2d888f48	394	/* Restore the original endianness */
d64567f6	395	spsr \|= PSR_AA32_ENDSTATE;
2d888f48	396
3dd681d9 WD	397	if (ka->sa.sa_flags & SA_RESTORER) {
	398	retcode = ptr_to_compat(ka->sa.sa_restorer);
	399	} else {
	400	/* Set up sigreturn pointer */
	401	unsigned int idx = thumb << 1;
	402
	403	if (ka->sa.sa_flags & SA_SIGINFO)
	404	idx += 3;
	405
0d747f65	406	retcode = (unsigned long)current->mm->context.vdso +
3dd681d9 WD	407	(idx << 2) + thumb;
	408	}
	409
	410	regs->regs[0] = usig;
	411	regs->compat_sp = ptr_to_compat(frame);
	412	regs->compat_lr = retcode;
	413	regs->pc = handler;
	414	regs->pstate = spsr;
3dd681d9 WD	415	}
	416
	417	static int compat_setup_sigframe(struct compat_sigframe __user *sf,
	418	struct pt_regs regs, sigset_t set)
	419	{
	420	struct compat_aux_sigframe __user *aux;
25dc2c80	421	unsigned long psr = pstate_to_compat_psr(regs->pstate);
3dd681d9 WD	422	int err = 0;
	423
	424	__put_user_error(regs->regs[0], &sf->uc.uc_mcontext.arm_r0, err);
	425	__put_user_error(regs->regs[1], &sf->uc.uc_mcontext.arm_r1, err);
	426	__put_user_error(regs->regs[2], &sf->uc.uc_mcontext.arm_r2, err);
	427	__put_user_error(regs->regs[3], &sf->uc.uc_mcontext.arm_r3, err);
	428	__put_user_error(regs->regs[4], &sf->uc.uc_mcontext.arm_r4, err);
	429	__put_user_error(regs->regs[5], &sf->uc.uc_mcontext.arm_r5, err);
	430	__put_user_error(regs->regs[6], &sf->uc.uc_mcontext.arm_r6, err);
	431	__put_user_error(regs->regs[7], &sf->uc.uc_mcontext.arm_r7, err);
	432	__put_user_error(regs->regs[8], &sf->uc.uc_mcontext.arm_r8, err);
	433	__put_user_error(regs->regs[9], &sf->uc.uc_mcontext.arm_r9, err);
	434	__put_user_error(regs->regs[10], &sf->uc.uc_mcontext.arm_r10, err);
	435	__put_user_error(regs->regs[11], &sf->uc.uc_mcontext.arm_fp, err);
	436	__put_user_error(regs->regs[12], &sf->uc.uc_mcontext.arm_ip, err);
	437	__put_user_error(regs->compat_sp, &sf->uc.uc_mcontext.arm_sp, err);
	438	__put_user_error(regs->compat_lr, &sf->uc.uc_mcontext.arm_lr, err);
	439	__put_user_error(regs->pc, &sf->uc.uc_mcontext.arm_pc, err);
25dc2c80	440	__put_user_error(psr, &sf->uc.uc_mcontext.arm_cpsr, err);
3dd681d9 WD	441
3dd681d9 WD	442	__put_user_error((compat_ulong_t)0, &sf->uc.uc_mcontext.trap_no, err);
9141300a	443	/* set the compat FSR WnR */
aed40e01	444	__put_user_error(!!(current->thread.fault_code & ESR_ELx_WNR) <<
9141300a	445	FSR_WRITE_SHIFT, &sf->uc.uc_mcontext.error_code, err);
3dd681d9 WD	446	__put_user_error(current->thread.fault_address, &sf->uc.uc_mcontext.fault_address, err);
	447	__put_user_error(set->sig[0], &sf->uc.uc_mcontext.oldmask, err);
	448
	449	err \|= put_sigset_t(&sf->uc.uc_sigmask, set);
	450
	451	aux = (struct compat_aux_sigframe __user *) sf->uc.uc_regspace;
	452
	453	if (err == 0)
	454	err \|= compat_preserve_vfp_context(&aux->vfp);
	455	__put_user_error(0, &aux->end_magic, err);
	456
	457	return err;
	458	}
	459
	460	/*
	461	* 32-bit signal handling routines called from signal.c
	462	*/
00554fa4	463	int compat_setup_rt_frame(int usig, struct ksignal *ksig,
3dd681d9 WD	464	sigset_t set, struct pt_regs regs)
	465	{
	466	struct compat_rt_sigframe __user *frame;
3dd681d9 WD	467	int err = 0;
3dd681d9 WD	468
38a7be3c	469	frame = compat_get_sigframe(ksig, regs, sizeof(*frame));
3dd681d9 WD	470
	471	if (!frame)
	472	return 1;
	473
00554fa4	474	err \|= copy_siginfo_to_user32(&frame->info, &ksig->info);
3dd681d9 WD	475
3dd681d9 WD	476	__put_user_error(0, &frame->sig.uc.uc_flags, err);
c0e01d5d	477	__put_user_error(0, &frame->sig.uc.uc_link, err);
3dd681d9	478
207bdae4	479	err \|= __compat_save_altstack(&frame->sig.uc.uc_stack, regs->compat_sp);
3dd681d9 WD	480
3dd681d9 WD	481	err \|= compat_setup_sigframe(&frame->sig, regs, set);
3dd681d9 WD	482
3dd681d9 WD	483	if (err == 0) {
00554fa4	484	compat_setup_return(regs, &ksig->ka, frame->sig.retcode, frame, usig);
3dd681d9 WD	485	regs->regs[1] = (compat_ulong_t)(unsigned long)&frame->info;
	486	regs->regs[2] = (compat_ulong_t)(unsigned long)&frame->sig.uc;
	487	}
	488
	489	return err;
	490	}
	491
00554fa4	492	int compat_setup_frame(int usig, struct ksignal ksig, sigset_t set,
3dd681d9 WD	493	struct pt_regs *regs)
	494	{
	495	struct compat_sigframe __user *frame;
	496	int err = 0;
	497
38a7be3c	498	frame = compat_get_sigframe(ksig, regs, sizeof(*frame));
3dd681d9 WD	499
	500	if (!frame)
	501	return 1;
	502
	503	__put_user_error(0x5ac3c35a, &frame->uc.uc_flags, err);
	504
	505	err \|= compat_setup_sigframe(frame, regs, set);
	506	if (err == 0)
00554fa4	507	compat_setup_return(regs, &ksig->ka, frame->retcode, frame, usig);
3dd681d9 WD	508
	509	return err;
	510	}
	511
3dd681d9 WD	512	void compat_setup_restart_syscall(struct pt_regs *regs)
3dd681d9 WD	513	{
4ed27ecf	514	regs->regs[7] = __NR_compat_restart_syscall;
3dd681d9	515	}