[mirror_ubuntu-zesty-kernel.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/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;
}

int copy_siginfo_to_user32(compat_siginfo_t __user *to, const siginfo_t *from)
{
	int err;

	if (!access_ok(VERIFY_WRITE, to, sizeof(*to)))
		return -EFAULT;

	/* If you change siginfo_t structure, please be sure
	 * this code is fixed accordingly.
	 * It should never copy any pad contained in the structure
	 * to avoid security leaks, but must copy the generic
	 * 3 ints plus the relevant union member.
	 * This routine must convert siginfo from 64bit to 32bit as well
	 * at the same time.
	 */
	err = __put_user(from->si_signo, &to->si_signo);
	err |= __put_user(from->si_errno, &to->si_errno);
	err |= __put_user((short)from->si_code, &to->si_code);
	if (from->si_code < 0)
		err |= __copy_to_user(&to->_sifields._pad, &from->_sifields._pad,
				      SI_PAD_SIZE);
	else switch (from->si_code & __SI_MASK) {
	case __SI_KILL:
		err |= __put_user(from->si_pid, &to->si_pid);
		err |= __put_user(from->si_uid, &to->si_uid);
		break;
	case __SI_TIMER:
		 err |= __put_user(from->si_tid, &to->si_tid);
		 err |= __put_user(from->si_overrun, &to->si_overrun);
		 err |= __put_user((compat_uptr_t)(unsigned long)from->si_ptr,
				   &to->si_ptr);
		break;
	case __SI_POLL:
		err |= __put_user(from->si_band, &to->si_band);
		err |= __put_user(from->si_fd, &to->si_fd);
		break;
	case __SI_FAULT:
		err |= __put_user((compat_uptr_t)(unsigned long)from->si_addr,
				  &to->si_addr);
#ifdef BUS_MCEERR_AO
		/*
		 * Other callers might not initialize the si_lsb field,
		 * so check explicitely for the right codes here.
		 */
		if (from->si_code == BUS_MCEERR_AR || from->si_code == BUS_MCEERR_AO)
			err |= __put_user(from->si_addr_lsb, &to->si_addr_lsb);
#endif
		break;
	case __SI_CHLD:
		err |= __put_user(from->si_pid, &to->si_pid);
		err |= __put_user(from->si_uid, &to->si_uid);
		err |= __put_user(from->si_status, &to->si_status);
		err |= __put_user(from->si_utime, &to->si_utime);
		err |= __put_user(from->si_stime, &to->si_stime);
		break;
	case __SI_RT: /* This is not generated by the kernel as of now. */
	case __SI_MESGQ: /* But this is */
		err |= __put_user(from->si_pid, &to->si_pid);
		err |= __put_user(from->si_uid, &to->si_uid);
		err |= __put_user((compat_uptr_t)(unsigned long)from->si_ptr, &to->si_ptr);
		break;
	case __SI_SYS:
		err |= __put_user((compat_uptr_t)(unsigned long)
				from->si_call_addr, &to->si_call_addr);
		err |= __put_user(from->si_syscall, &to->si_syscall);
		err |= __put_user(from->si_arch, &to->si_arch);
		break;
	default: /* this is just in case for now ... */
		err |= __put_user(from->si_pid, &to->si_pid);
		err |= __put_user(from->si_uid, &to->si_uid);
		break;
	}
	return err;
}

int copy_siginfo_from_user32(siginfo_t *to, compat_siginfo_t __user *from)
{
	memset(to, 0, sizeof *to);

	if (copy_from_user(to, from, __ARCH_SI_PREAMBLE_SIZE) ||
	    copy_from_user(to->_sifields._pad,
			   from->_sifields._pad, SI_PAD_SIZE))
		return -EFAULT;

	return 0;
}

/*
 * VFP save/restore code.
 */
static int compat_preserve_vfp_context(struct compat_vfp_sigframe __user *frame)
{
	struct fpsimd_state *fpsimd = &current->thread.fpsimd_state;
	compat_ulong_t magic = VFP_MAGIC;
	compat_ulong_t size = VFP_STORAGE_SIZE;
	compat_ulong_t fpscr, fpexc;
	int 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_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.
	 * FIXME: Won't work if big endian.
	 */
	err |= __copy_to_user(&frame->ufp.fpregs, fpsimd->vregs,
			      sizeof(frame->ufp.fpregs));

	/* 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 fpsimd_state fpsimd;
	compat_ulong_t magic = VFP_MAGIC;
	compat_ulong_t size = VFP_STORAGE_SIZE;
	compat_ulong_t fpscr;
	int 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.
	 * FIXME: Won't work if big endian.
	 */
	err |= __copy_from_user(fpsimd.vregs, frame->ufp.fpregs,
				sizeof(frame->ufp.fpregs));

	/* 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;

	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(regs->pstate, &sf->uc.uc_mcontext.arm_cpsr, err);

	/*
	 * Avoid compat_sys_sigreturn() restarting.
	 */
	regs->syscallno = ~0UL;

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

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

	return err;
}

asmlinkage int compat_sys_sigreturn(struct pt_regs *regs)
{
	struct compat_sigframe __user *frame;

	/* Always make any pending restarted system calls return -EINTR */
	current_thread_info()->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(VERIFY_READ, frame, sizeof (*frame)))
		goto badframe;

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

	return regs->regs[0];

badframe:
	if (show_unhandled_signals)
		pr_info_ratelimited("%s[%d]: bad frame in %s: pc=%08llx sp=%08llx\n",
				    current->comm, task_pid_nr(current), __func__,
				    regs->pc, regs->sp);
	force_sig(SIGSEGV, current);
	return 0;
}

asmlinkage int compat_sys_rt_sigreturn(struct pt_regs *regs)
{
	struct compat_rt_sigframe __user *frame;

	/* Always make any pending restarted system calls return -EINTR */
	current_thread_info()->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(VERIFY_READ, 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:
	if (show_unhandled_signals)
		pr_info_ratelimited("%s[%d]: bad frame in %s: pc=%08llx sp=%08llx\n",
				    current->comm, task_pid_nr(current), __func__,
				    regs->pc, regs->sp);
	force_sig(SIGSEGV, current);
	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(VERIFY_WRITE, 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;
	int thumb;

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

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

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

	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 = AARCH32_VECTORS_BASE +
			  AARCH32_KERN_SIGRET_CODE_OFFSET +
			  (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;
	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(regs->pstate, &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>
	28	#include <asm/signal32.h>
	29	#include <asm/uaccess.h>
f3e5c847	30	#include <asm/unistd.h>
3dd681d9	31
3dd681d9 WD	32	struct compat_sigcontext {
	33	/* We always set these two fields to 0 */
	34	compat_ulong_t trap_no;
	35	compat_ulong_t error_code;
	36
	37	compat_ulong_t oldmask;
	38	compat_ulong_t arm_r0;
	39	compat_ulong_t arm_r1;
	40	compat_ulong_t arm_r2;
	41	compat_ulong_t arm_r3;
	42	compat_ulong_t arm_r4;
	43	compat_ulong_t arm_r5;
	44	compat_ulong_t arm_r6;
	45	compat_ulong_t arm_r7;
	46	compat_ulong_t arm_r8;
	47	compat_ulong_t arm_r9;
	48	compat_ulong_t arm_r10;
	49	compat_ulong_t arm_fp;
	50	compat_ulong_t arm_ip;
	51	compat_ulong_t arm_sp;
	52	compat_ulong_t arm_lr;
	53	compat_ulong_t arm_pc;
	54	compat_ulong_t arm_cpsr;
	55	compat_ulong_t fault_address;
	56	};
	57
	58	struct compat_ucontext {
	59	compat_ulong_t uc_flags;
c0e01d5d	60	compat_uptr_t uc_link;
3dd681d9 WD	61	compat_stack_t uc_stack;
	62	struct compat_sigcontext uc_mcontext;
	63	compat_sigset_t uc_sigmask;
	64	int __unused[32 - (sizeof (compat_sigset_t) / sizeof (int))];
	65	compat_ulong_t uc_regspace[128] __attribute__((__aligned__(8)));
	66	};
	67
	68	struct compat_vfp_sigframe {
	69	compat_ulong_t magic;
	70	compat_ulong_t size;
	71	struct compat_user_vfp {
	72	compat_u64 fpregs[32];
	73	compat_ulong_t fpscr;
	74	} ufp;
	75	struct compat_user_vfp_exc {
	76	compat_ulong_t fpexc;
	77	compat_ulong_t fpinst;
	78	compat_ulong_t fpinst2;
	79	} ufp_exc;
	80	} __attribute__((__aligned__(8)));
	81
	82	#define VFP_MAGIC 0x56465001
	83	#define VFP_STORAGE_SIZE sizeof(struct compat_vfp_sigframe)
	84
9141300a CM	85	#define FSR_WRITE_SHIFT (11)
9141300a CM	86
3dd681d9 WD	87	struct compat_aux_sigframe {
	88	struct compat_vfp_sigframe vfp;
	89
	90	/* Something that isn't a valid magic number for any coprocessor. */
	91	unsigned long end_magic;
	92	} __attribute__((__aligned__(8)));
	93
	94	struct compat_sigframe {
	95	struct compat_ucontext uc;
	96	compat_ulong_t retcode[2];
	97	};
	98
	99	struct compat_rt_sigframe {
	100	struct compat_siginfo info;
	101	struct compat_sigframe sig;
	102	};
	103
	104	#define _BLOCKABLE (~(sigmask(SIGKILL) \| sigmask(SIGSTOP)))
	105
3dd681d9 WD	106	static inline int put_sigset_t(compat_sigset_t __user uset, sigset_t set)
	107	{
	108	compat_sigset_t cset;
	109
	110	cset.sig[0] = set->sig[0] & 0xffffffffull;
	111	cset.sig[1] = set->sig[0] >> 32;
	112
	113	return copy_to_user(uset, &cset, sizeof(*uset));
	114	}
	115
	116	static inline int get_sigset_t(sigset_t *set,
	117	const compat_sigset_t __user *uset)
	118	{
	119	compat_sigset_t s32;
	120
	121	if (copy_from_user(&s32, uset, sizeof(*uset)))
	122	return -EFAULT;
	123
	124	set->sig[0] = s32.sig[0] \| (((long)s32.sig[1]) << 32);
	125	return 0;
	126	}
	127
ce395960	128	int copy_siginfo_to_user32(compat_siginfo_t __user to, const siginfo_t from)
3dd681d9 WD	129	{
	130	int err;
	131
	132	if (!access_ok(VERIFY_WRITE, to, sizeof(*to)))
	133	return -EFAULT;
	134
	135	/* If you change siginfo_t structure, please be sure
	136	* this code is fixed accordingly.
	137	* It should never copy any pad contained in the structure
	138	* to avoid security leaks, but must copy the generic
	139	* 3 ints plus the relevant union member.
	140	* This routine must convert siginfo from 64bit to 32bit as well
	141	* at the same time.
	142	*/
	143	err = __put_user(from->si_signo, &to->si_signo);
	144	err \|= __put_user(from->si_errno, &to->si_errno);
	145	err \|= __put_user((short)from->si_code, &to->si_code);
	146	if (from->si_code < 0)
	147	err \|= __copy_to_user(&to->_sifields._pad, &from->_sifields._pad,
	148	SI_PAD_SIZE);
	149	else switch (from->si_code & __SI_MASK) {
	150	case __SI_KILL:
	151	err \|= __put_user(from->si_pid, &to->si_pid);
	152	err \|= __put_user(from->si_uid, &to->si_uid);
	153	break;
	154	case __SI_TIMER:
	155	err \|= __put_user(from->si_tid, &to->si_tid);
	156	err \|= __put_user(from->si_overrun, &to->si_overrun);
	157	err \|= __put_user((compat_uptr_t)(unsigned long)from->si_ptr,
	158	&to->si_ptr);
	159	break;
	160	case __SI_POLL:
	161	err \|= __put_user(from->si_band, &to->si_band);
	162	err \|= __put_user(from->si_fd, &to->si_fd);
	163	break;
	164	case __SI_FAULT:
	165	err \|= __put_user((compat_uptr_t)(unsigned long)from->si_addr,
	166	&to->si_addr);
	167	#ifdef BUS_MCEERR_AO
	168	/*
	169	* Other callers might not initialize the si_lsb field,
	170	* so check explicitely for the right codes here.
	171	*/
	172	if (from->si_code == BUS_MCEERR_AR \|\| from->si_code == BUS_MCEERR_AO)
	173	err \|= __put_user(from->si_addr_lsb, &to->si_addr_lsb);
	174	#endif
	175	break;
	176	case __SI_CHLD:
	177	err \|= __put_user(from->si_pid, &to->si_pid);
	178	err \|= __put_user(from->si_uid, &to->si_uid);
	179	err \|= __put_user(from->si_status, &to->si_status);
	180	err \|= __put_user(from->si_utime, &to->si_utime);
	181	err \|= __put_user(from->si_stime, &to->si_stime);
	182	break;
	183	case __SI_RT: /* This is not generated by the kernel as of now. */
	184	case __SI_MESGQ: /* But this is */
	185	err \|= __put_user(from->si_pid, &to->si_pid);
	186	err \|= __put_user(from->si_uid, &to->si_uid);
	187	err \|= __put_user((compat_uptr_t)(unsigned long)from->si_ptr, &to->si_ptr);
	188	break;
cc5e9097 AT	189	case __SI_SYS:
	190	err \|= __put_user((compat_uptr_t)(unsigned long)
	191	from->si_call_addr, &to->si_call_addr);
	192	err \|= __put_user(from->si_syscall, &to->si_syscall);
	193	err \|= __put_user(from->si_arch, &to->si_arch);
	194	break;
3dd681d9 WD	195	default: /* this is just in case for now ... */
	196	err \|= __put_user(from->si_pid, &to->si_pid);
	197	err \|= __put_user(from->si_uid, &to->si_uid);
	198	break;
	199	}
	200	return err;
	201	}
	202
	203	int copy_siginfo_from_user32(siginfo_t to, compat_siginfo_t __user from)
	204	{
	205	memset(to, 0, sizeof *to);
	206
	207	if (copy_from_user(to, from, __ARCH_SI_PREAMBLE_SIZE) \|\|
	208	copy_from_user(to->_sifields._pad,
	209	from->_sifields._pad, SI_PAD_SIZE))
	210	return -EFAULT;
	211
	212	return 0;
	213	}
	214
	215	/*
	216	* VFP save/restore code.
	217	*/
	218	static int compat_preserve_vfp_context(struct compat_vfp_sigframe __user *frame)
	219	{
	220	struct fpsimd_state *fpsimd = &current->thread.fpsimd_state;
	221	compat_ulong_t magic = VFP_MAGIC;
	222	compat_ulong_t size = VFP_STORAGE_SIZE;
	223	compat_ulong_t fpscr, fpexc;
	224	int err = 0;
	225
	226	/*
	227	* Save the hardware registers to the fpsimd_state structure.
	228	* Note that this also saves V16-31, which aren't visible
	229	* in AArch32.
	230	*/
c51f9269	231	fpsimd_preserve_current_state();
3dd681d9 WD	232
	233	/* Place structure header on the stack */
	234	__put_user_error(magic, &frame->magic, err);
	235	__put_user_error(size, &frame->size, err);
	236
	237	/*
	238	* Now copy the FP registers. Since the registers are packed,
	239	* we can copy the prefix we want (V0-V15) as it is.
	240	* FIXME: Won't work if big endian.
	241	*/
	242	err \|= __copy_to_user(&frame->ufp.fpregs, fpsimd->vregs,
	243	sizeof(frame->ufp.fpregs));
	244
	245	/* Create an AArch32 fpscr from the fpsr and the fpcr. */
	246	fpscr = (fpsimd->fpsr & VFP_FPSCR_STAT_MASK) \|
	247	(fpsimd->fpcr & VFP_FPSCR_CTRL_MASK);
	248	__put_user_error(fpscr, &frame->ufp.fpscr, err);
	249
	250	/*
	251	* The exception register aren't available so we fake up a
	252	* basic FPEXC and zero everything else.
	253	*/
	254	fpexc = (1 << 30);
	255	__put_user_error(fpexc, &frame->ufp_exc.fpexc, err);
	256	__put_user_error(0, &frame->ufp_exc.fpinst, err);
	257	__put_user_error(0, &frame->ufp_exc.fpinst2, err);
	258
	259	return err ? -EFAULT : 0;
	260	}
	261
	262	static int compat_restore_vfp_context(struct compat_vfp_sigframe __user *frame)
	263	{
	264	struct fpsimd_state fpsimd;
	265	compat_ulong_t magic = VFP_MAGIC;
	266	compat_ulong_t size = VFP_STORAGE_SIZE;
	267	compat_ulong_t fpscr;
	268	int err = 0;
	269
	270	__get_user_error(magic, &frame->magic, err);
	271	__get_user_error(size, &frame->size, err);
	272
	273	if (err)
	274	return -EFAULT;
	275	if (magic != VFP_MAGIC \|\| size != VFP_STORAGE_SIZE)
	276	return -EINVAL;
	277
	278	/*
	279	* Copy the FP registers into the start of the fpsimd_state.
	280	* FIXME: Won't work if big endian.
	281	*/
	282	err \|= __copy_from_user(fpsimd.vregs, frame->ufp.fpregs,
	283	sizeof(frame->ufp.fpregs));
	284
	285	/* Extract the fpsr and the fpcr from the fpscr */
	286	__get_user_error(fpscr, &frame->ufp.fpscr, err);
	287	fpsimd.fpsr = fpscr & VFP_FPSCR_STAT_MASK;
	288	fpsimd.fpcr = fpscr & VFP_FPSCR_CTRL_MASK;
	289
	290	/*
	291	* We don't need to touch the exception register, so
	292	* reload the hardware state.
	293	*/
c51f9269 AB	294	if (!err)
c51f9269 AB	295	fpsimd_update_current_state(&fpsimd);
3dd681d9 WD	296
	297	return err ? -EFAULT : 0;
	298	}
	299
3dd681d9 WD	300	static int compat_restore_sigframe(struct pt_regs *regs,
	301	struct compat_sigframe __user *sf)
	302	{
	303	int err;
	304	sigset_t set;
	305	struct compat_aux_sigframe __user *aux;
	306
	307	err = get_sigset_t(&set, &sf->uc.uc_sigmask);
	308	if (err == 0) {
	309	sigdelsetmask(&set, ~_BLOCKABLE);
	310	set_current_blocked(&set);
	311	}
	312
	313	__get_user_error(regs->regs[0], &sf->uc.uc_mcontext.arm_r0, err);
	314	__get_user_error(regs->regs[1], &sf->uc.uc_mcontext.arm_r1, err);
	315	__get_user_error(regs->regs[2], &sf->uc.uc_mcontext.arm_r2, err);
	316	__get_user_error(regs->regs[3], &sf->uc.uc_mcontext.arm_r3, err);
	317	__get_user_error(regs->regs[4], &sf->uc.uc_mcontext.arm_r4, err);
	318	__get_user_error(regs->regs[5], &sf->uc.uc_mcontext.arm_r5, err);
	319	__get_user_error(regs->regs[6], &sf->uc.uc_mcontext.arm_r6, err);
	320	__get_user_error(regs->regs[7], &sf->uc.uc_mcontext.arm_r7, err);
	321	__get_user_error(regs->regs[8], &sf->uc.uc_mcontext.arm_r8, err);
	322	__get_user_error(regs->regs[9], &sf->uc.uc_mcontext.arm_r9, err);
	323	__get_user_error(regs->regs[10], &sf->uc.uc_mcontext.arm_r10, err);
	324	__get_user_error(regs->regs[11], &sf->uc.uc_mcontext.arm_fp, err);
	325	__get_user_error(regs->regs[12], &sf->uc.uc_mcontext.arm_ip, err);
	326	__get_user_error(regs->compat_sp, &sf->uc.uc_mcontext.arm_sp, err);
	327	__get_user_error(regs->compat_lr, &sf->uc.uc_mcontext.arm_lr, err);
	328	__get_user_error(regs->pc, &sf->uc.uc_mcontext.arm_pc, err);
	329	__get_user_error(regs->pstate, &sf->uc.uc_mcontext.arm_cpsr, err);
	330
	331	/*
	332	* Avoid compat_sys_sigreturn() restarting.
	333	*/
	334	regs->syscallno = ~0UL;
	335
	336	err \|= !valid_user_regs(&regs->user_regs);
	337
	338	aux = (struct compat_aux_sigframe __user *) sf->uc.uc_regspace;
	339	if (err == 0)
	340	err \|= compat_restore_vfp_context(&aux->vfp);
	341
	342	return err;
	343	}
	344
	345	asmlinkage int compat_sys_sigreturn(struct pt_regs *regs)
	346	{
	347	struct compat_sigframe __user *frame;
	348
	349	/* Always make any pending restarted system calls return -EINTR */
	350	current_thread_info()->restart_block.fn = do_no_restart_syscall;
	351
	352	/*
	353	* Since we stacked the signal on a 64-bit boundary,
	354	* then 'sp' should be word aligned here. If it's
	355	* not, then the user is trying to mess with us.
	356	*/
	357	if (regs->compat_sp & 7)
	358	goto badframe;
	359
	360	frame = (struct compat_sigframe __user *)regs->compat_sp;
	361
	362	if (!access_ok(VERIFY_READ, frame, sizeof (*frame)))
	363	goto badframe;
364
365	if (compat_restore_sigframe(regs, frame))
366	goto badframe;
367
368	return regs->regs[0];
369
370	badframe:
371	if (show_unhandled_signals)
372	pr_info_ratelimited("%s[%d]: bad frame in %s: pc=%08llx sp=%08llx\n",
373	current->comm, task_pid_nr(current), __func__,
374	regs->pc, regs->sp);
375	force_sig(SIGSEGV, current);
376	return 0;
377	}
378
379	asmlinkage int compat_sys_rt_sigreturn(struct pt_regs *regs)
380	{
381	struct compat_rt_sigframe __user *frame;
382
383	/* Always make any pending restarted system calls return -EINTR */
384	current_thread_info()->restart_block.fn = do_no_restart_syscall;
385
386	/*
387	* Since we stacked the signal on a 64-bit boundary,
388	* then 'sp' should be word aligned here. If it's
389	* not, then the user is trying to mess with us.
390	*/
391	if (regs->compat_sp & 7)
392	goto badframe;
393
394	frame = (struct compat_rt_sigframe __user *)regs->compat_sp;
395
396	if (!access_ok(VERIFY_READ, frame, sizeof (*frame)))
397	goto badframe;
398
399	if (compat_restore_sigframe(regs, &frame->sig))
400	goto badframe;
401
207bdae4	402	if (compat_restore_altstack(&frame->sig.uc.uc_stack))
3dd681d9 WD	403	goto badframe;
	404
	405	return regs->regs[0];
	406
	407	badframe:
	408	if (show_unhandled_signals)
	409	pr_info_ratelimited("%s[%d]: bad frame in %s: pc=%08llx sp=%08llx\n",
	410	current->comm, task_pid_nr(current), __func__,
	411	regs->pc, regs->sp);
	412	force_sig(SIGSEGV, current);
	413	return 0;
	414	}
	415
38a7be3c	416	static void __user compat_get_sigframe(struct ksignal ksig,
88a24cff WD	417	struct pt_regs *regs,
88a24cff WD	418	int framesize)
3dd681d9	419	{
38a7be3c	420	compat_ulong_t sp = sigsp(regs->compat_sp, ksig);
3dd681d9 WD	421	void __user *frame;
3dd681d9 WD	422
3dd681d9 WD	423	/*
	424	* ATPCS B01 mandates 8-byte alignment
	425	*/
	426	frame = compat_ptr((compat_uptr_t)((sp - framesize) & ~7));
	427
	428	/*
	429	* Check that we can actually write to the signal frame.
	430	*/
	431	if (!access_ok(VERIFY_WRITE, frame, framesize))
	432	frame = NULL;
	433
	434	return frame;
	435	}
	436
060a18c7 WD	437	static void compat_setup_return(struct pt_regs regs, struct k_sigaction ka,
	438	compat_ulong_t __user rc, void __user frame,
	439	int usig)
3dd681d9 WD	440	{
	441	compat_ulong_t handler = ptr_to_compat(ka->sa.sa_handler);
	442	compat_ulong_t retcode;
	443	compat_ulong_t spsr = regs->pstate & ~PSR_f;
	444	int thumb;
	445
	446	/* Check if the handler is written for ARM or Thumb */
	447	thumb = handler & 1;
	448
aa62c209	449	if (thumb)
3dd681d9	450	spsr \|= COMPAT_PSR_T_BIT;
aa62c209	451	else
3dd681d9	452	spsr &= ~COMPAT_PSR_T_BIT;
aa62c209 P	453
	454	/* The IT state must be cleared for both ARM and Thumb-2 */
	455	spsr &= ~COMPAT_PSR_IT_MASK;
3dd681d9 WD	456
	457	if (ka->sa.sa_flags & SA_RESTORER) {
	458	retcode = ptr_to_compat(ka->sa.sa_restorer);
	459	} else {
	460	/* Set up sigreturn pointer */
	461	unsigned int idx = thumb << 1;
	462
	463	if (ka->sa.sa_flags & SA_SIGINFO)
	464	idx += 3;
	465
	466	retcode = AARCH32_VECTORS_BASE +
	467	AARCH32_KERN_SIGRET_CODE_OFFSET +
	468	(idx << 2) + thumb;
	469	}
	470
	471	regs->regs[0] = usig;
	472	regs->compat_sp = ptr_to_compat(frame);
	473	regs->compat_lr = retcode;
	474	regs->pc = handler;
	475	regs->pstate = spsr;
3dd681d9 WD	476	}
	477
	478	static int compat_setup_sigframe(struct compat_sigframe __user *sf,
	479	struct pt_regs regs, sigset_t set)
	480	{
	481	struct compat_aux_sigframe __user *aux;
	482	int err = 0;
	483
	484	__put_user_error(regs->regs[0], &sf->uc.uc_mcontext.arm_r0, err);
	485	__put_user_error(regs->regs[1], &sf->uc.uc_mcontext.arm_r1, err);
	486	__put_user_error(regs->regs[2], &sf->uc.uc_mcontext.arm_r2, err);
	487	__put_user_error(regs->regs[3], &sf->uc.uc_mcontext.arm_r3, err);
	488	__put_user_error(regs->regs[4], &sf->uc.uc_mcontext.arm_r4, err);
	489	__put_user_error(regs->regs[5], &sf->uc.uc_mcontext.arm_r5, err);
	490	__put_user_error(regs->regs[6], &sf->uc.uc_mcontext.arm_r6, err);
	491	__put_user_error(regs->regs[7], &sf->uc.uc_mcontext.arm_r7, err);
	492	__put_user_error(regs->regs[8], &sf->uc.uc_mcontext.arm_r8, err);
	493	__put_user_error(regs->regs[9], &sf->uc.uc_mcontext.arm_r9, err);
	494	__put_user_error(regs->regs[10], &sf->uc.uc_mcontext.arm_r10, err);
	495	__put_user_error(regs->regs[11], &sf->uc.uc_mcontext.arm_fp, err);
	496	__put_user_error(regs->regs[12], &sf->uc.uc_mcontext.arm_ip, err);
	497	__put_user_error(regs->compat_sp, &sf->uc.uc_mcontext.arm_sp, err);
	498	__put_user_error(regs->compat_lr, &sf->uc.uc_mcontext.arm_lr, err);
	499	__put_user_error(regs->pc, &sf->uc.uc_mcontext.arm_pc, err);
	500	__put_user_error(regs->pstate, &sf->uc.uc_mcontext.arm_cpsr, err);
	501
	502	__put_user_error((compat_ulong_t)0, &sf->uc.uc_mcontext.trap_no, err);
9141300a	503	/* set the compat FSR WnR */
aed40e01	504	__put_user_error(!!(current->thread.fault_code & ESR_ELx_WNR) <<
9141300a	505	FSR_WRITE_SHIFT, &sf->uc.uc_mcontext.error_code, err);
3dd681d9 WD	506	__put_user_error(current->thread.fault_address, &sf->uc.uc_mcontext.fault_address, err);
	507	__put_user_error(set->sig[0], &sf->uc.uc_mcontext.oldmask, err);
	508
	509	err \|= put_sigset_t(&sf->uc.uc_sigmask, set);
	510
	511	aux = (struct compat_aux_sigframe __user *) sf->uc.uc_regspace;
	512
	513	if (err == 0)
	514	err \|= compat_preserve_vfp_context(&aux->vfp);
	515	__put_user_error(0, &aux->end_magic, err);
	516
	517	return err;
	518	}
	519
	520	/*
	521	* 32-bit signal handling routines called from signal.c
	522	*/
00554fa4	523	int compat_setup_rt_frame(int usig, struct ksignal *ksig,
3dd681d9 WD	524	sigset_t set, struct pt_regs regs)
	525	{
	526	struct compat_rt_sigframe __user *frame;
3dd681d9 WD	527	int err = 0;
3dd681d9 WD	528
38a7be3c	529	frame = compat_get_sigframe(ksig, regs, sizeof(*frame));
3dd681d9 WD	530
	531	if (!frame)
	532	return 1;
	533
00554fa4	534	err \|= copy_siginfo_to_user32(&frame->info, &ksig->info);
3dd681d9 WD	535
3dd681d9 WD	536	__put_user_error(0, &frame->sig.uc.uc_flags, err);
c0e01d5d	537	__put_user_error(0, &frame->sig.uc.uc_link, err);
3dd681d9	538
207bdae4	539	err \|= __compat_save_altstack(&frame->sig.uc.uc_stack, regs->compat_sp);
3dd681d9 WD	540
3dd681d9 WD	541	err \|= compat_setup_sigframe(&frame->sig, regs, set);
3dd681d9 WD	542
3dd681d9 WD	543	if (err == 0) {
00554fa4	544	compat_setup_return(regs, &ksig->ka, frame->sig.retcode, frame, usig);
3dd681d9 WD	545	regs->regs[1] = (compat_ulong_t)(unsigned long)&frame->info;
	546	regs->regs[2] = (compat_ulong_t)(unsigned long)&frame->sig.uc;
	547	}
	548
	549	return err;
	550	}
	551
00554fa4	552	int compat_setup_frame(int usig, struct ksignal ksig, sigset_t set,
3dd681d9 WD	553	struct pt_regs *regs)
	554	{
	555	struct compat_sigframe __user *frame;
	556	int err = 0;
	557
38a7be3c	558	frame = compat_get_sigframe(ksig, regs, sizeof(*frame));
3dd681d9 WD	559
	560	if (!frame)
	561	return 1;
	562
	563	__put_user_error(0x5ac3c35a, &frame->uc.uc_flags, err);
	564
	565	err \|= compat_setup_sigframe(frame, regs, set);
	566	if (err == 0)
00554fa4	567	compat_setup_return(regs, &ksig->ka, frame->retcode, frame, usig);
3dd681d9 WD	568
	569	return err;
	570	}
	571
3dd681d9 WD	572	void compat_setup_restart_syscall(struct pt_regs *regs)
3dd681d9 WD	573	{
4ed27ecf	574	regs->regs[7] = __NR_compat_restart_syscall;
3dd681d9	575	}