[deliverable/linux.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/fpsimd.h>
#include <asm/signal32.h>
#include <asm/uaccess.h>
#include <asm/unistd32.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)

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, 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;
	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_save_state(fpsimd);

	/* 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) {
		preempt_disable();
		fpsimd_load_state(&fpsimd);
		preempt_enable();
	}

	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 k_sigaction *ka,
					struct pt_regs *regs,
					int framesize)
{
	compat_ulong_t sp = regs->compat_sp;
	void __user *frame;

	/*
	 * This is the X/Open sanctioned signal stack switching.
	 */
	if ((ka->sa.sa_flags & SA_ONSTACK) && !sas_ss_flags(sp))
		sp = current->sas_ss_sp + current->sas_ss_size;

	/*
	 * 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;
		spsr &= ~COMPAT_PSR_IT_MASK;
	} else {
		spsr &= ~COMPAT_PSR_T_BIT;
	}

	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);
	__put_user_error((compat_ulong_t)0, &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 k_sigaction *ka, siginfo_t *info,
			  sigset_t *set, struct pt_regs *regs)
{
	struct compat_rt_sigframe __user *frame;
	int err = 0;

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

	if (!frame)
		return 1;

	err |= copy_siginfo_to_user32(&frame->info, 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, 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 k_sigaction *ka, sigset_t *set,
		       struct pt_regs *regs)
{
	struct compat_sigframe __user *frame;
	int err = 0;

	frame = compat_get_sigframe(ka, 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, 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
	26	#include <asm/fpsimd.h>
	27	#include <asm/signal32.h>
	28	#include <asm/uaccess.h>
f3d447a9	29	#include <asm/unistd32.h>
3dd681d9	30
3dd681d9 WD	31	struct compat_sigcontext {
	32	/* We always set these two fields to 0 */
	33	compat_ulong_t trap_no;
	34	compat_ulong_t error_code;
	35
	36	compat_ulong_t oldmask;
	37	compat_ulong_t arm_r0;
	38	compat_ulong_t arm_r1;
	39	compat_ulong_t arm_r2;
	40	compat_ulong_t arm_r3;
	41	compat_ulong_t arm_r4;
	42	compat_ulong_t arm_r5;
	43	compat_ulong_t arm_r6;
	44	compat_ulong_t arm_r7;
	45	compat_ulong_t arm_r8;
	46	compat_ulong_t arm_r9;
	47	compat_ulong_t arm_r10;
	48	compat_ulong_t arm_fp;
	49	compat_ulong_t arm_ip;
	50	compat_ulong_t arm_sp;
	51	compat_ulong_t arm_lr;
	52	compat_ulong_t arm_pc;
	53	compat_ulong_t arm_cpsr;
	54	compat_ulong_t fault_address;
	55	};
	56
	57	struct compat_ucontext {
	58	compat_ulong_t uc_flags;
c0e01d5d	59	compat_uptr_t uc_link;
3dd681d9 WD	60	compat_stack_t uc_stack;
	61	struct compat_sigcontext uc_mcontext;
	62	compat_sigset_t uc_sigmask;
	63	int __unused[32 - (sizeof (compat_sigset_t) / sizeof (int))];
	64	compat_ulong_t uc_regspace[128] __attribute__((__aligned__(8)));
	65	};
	66
	67	struct compat_vfp_sigframe {
	68	compat_ulong_t magic;
	69	compat_ulong_t size;
	70	struct compat_user_vfp {
	71	compat_u64 fpregs[32];
	72	compat_ulong_t fpscr;
	73	} ufp;
	74	struct compat_user_vfp_exc {
	75	compat_ulong_t fpexc;
	76	compat_ulong_t fpinst;
	77	compat_ulong_t fpinst2;
	78	} ufp_exc;
	79	} __attribute__((__aligned__(8)));
	80
	81	#define VFP_MAGIC 0x56465001
	82	#define VFP_STORAGE_SIZE sizeof(struct compat_vfp_sigframe)
	83
	84	struct compat_aux_sigframe {
	85	struct compat_vfp_sigframe vfp;
	86
	87	/* Something that isn't a valid magic number for any coprocessor. */
	88	unsigned long end_magic;
	89	} __attribute__((__aligned__(8)));
	90
	91	struct compat_sigframe {
	92	struct compat_ucontext uc;
	93	compat_ulong_t retcode[2];
	94	};
	95
	96	struct compat_rt_sigframe {
	97	struct compat_siginfo info;
	98	struct compat_sigframe sig;
	99	};
	100
	101	#define _BLOCKABLE (~(sigmask(SIGKILL) \| sigmask(SIGSTOP)))
	102
3dd681d9 WD	103	static inline int put_sigset_t(compat_sigset_t __user uset, sigset_t set)
	104	{
	105	compat_sigset_t cset;
	106
	107	cset.sig[0] = set->sig[0] & 0xffffffffull;
	108	cset.sig[1] = set->sig[0] >> 32;
	109
	110	return copy_to_user(uset, &cset, sizeof(*uset));
	111	}
	112
	113	static inline int get_sigset_t(sigset_t *set,
	114	const compat_sigset_t __user *uset)
	115	{
	116	compat_sigset_t s32;
	117
	118	if (copy_from_user(&s32, uset, sizeof(*uset)))
	119	return -EFAULT;
	120
	121	set->sig[0] = s32.sig[0] \| (((long)s32.sig[1]) << 32);
	122	return 0;
	123	}
	124
	125	int copy_siginfo_to_user32(compat_siginfo_t __user to, siginfo_t from)
	126	{
	127	int err;
	128
	129	if (!access_ok(VERIFY_WRITE, to, sizeof(*to)))
	130	return -EFAULT;
	131
	132	/* If you change siginfo_t structure, please be sure
	133	* this code is fixed accordingly.
	134	* It should never copy any pad contained in the structure
	135	* to avoid security leaks, but must copy the generic
	136	* 3 ints plus the relevant union member.
	137	* This routine must convert siginfo from 64bit to 32bit as well
	138	* at the same time.
	139	*/
	140	err = __put_user(from->si_signo, &to->si_signo);
	141	err \|= __put_user(from->si_errno, &to->si_errno);
	142	err \|= __put_user((short)from->si_code, &to->si_code);
	143	if (from->si_code < 0)
	144	err \|= __copy_to_user(&to->_sifields._pad, &from->_sifields._pad,
	145	SI_PAD_SIZE);
	146	else switch (from->si_code & __SI_MASK) {
	147	case __SI_KILL:
	148	err \|= __put_user(from->si_pid, &to->si_pid);
	149	err \|= __put_user(from->si_uid, &to->si_uid);
	150	break;
	151	case __SI_TIMER:
	152	err \|= __put_user(from->si_tid, &to->si_tid);
	153	err \|= __put_user(from->si_overrun, &to->si_overrun);
	154	err \|= __put_user((compat_uptr_t)(unsigned long)from->si_ptr,
	155	&to->si_ptr);
	156	break;
	157	case __SI_POLL:
	158	err \|= __put_user(from->si_band, &to->si_band);
	159	err \|= __put_user(from->si_fd, &to->si_fd);
	160	break;
	161	case __SI_FAULT:
	162	err \|= __put_user((compat_uptr_t)(unsigned long)from->si_addr,
	163	&to->si_addr);
	164	#ifdef BUS_MCEERR_AO
	165	/*
	166	* Other callers might not initialize the si_lsb field,
167	* so check explicitely for the right codes here.
168	*/
169	if (from->si_code == BUS_MCEERR_AR \|\| from->si_code == BUS_MCEERR_AO)
170	err \|= __put_user(from->si_addr_lsb, &to->si_addr_lsb);
171	#endif
172	break;
173	case __SI_CHLD:
174	err \|= __put_user(from->si_pid, &to->si_pid);
175	err \|= __put_user(from->si_uid, &to->si_uid);
176	err \|= __put_user(from->si_status, &to->si_status);
177	err \|= __put_user(from->si_utime, &to->si_utime);
178	err \|= __put_user(from->si_stime, &to->si_stime);
179	break;
180	case __SI_RT: /* This is not generated by the kernel as of now. */
181	case __SI_MESGQ: /* But this is */
182	err \|= __put_user(from->si_pid, &to->si_pid);
183	err \|= __put_user(from->si_uid, &to->si_uid);
184	err \|= __put_user((compat_uptr_t)(unsigned long)from->si_ptr, &to->si_ptr);
185	break;
186	default: /* this is just in case for now ... */
187	err \|= __put_user(from->si_pid, &to->si_pid);
188	err \|= __put_user(from->si_uid, &to->si_uid);
189	break;
190	}
191	return err;
192	}
193
194	int copy_siginfo_from_user32(siginfo_t to, compat_siginfo_t __user from)
195	{
196	memset(to, 0, sizeof *to);
197
198	if (copy_from_user(to, from, __ARCH_SI_PREAMBLE_SIZE) \|\|
199	copy_from_user(to->_sifields._pad,
200	from->_sifields._pad, SI_PAD_SIZE))
201	return -EFAULT;
202
203	return 0;
204	}
205
206	/*
207	* VFP save/restore code.
208	*/
209	static int compat_preserve_vfp_context(struct compat_vfp_sigframe __user *frame)
210	{
211	struct fpsimd_state *fpsimd = &current->thread.fpsimd_state;
212	compat_ulong_t magic = VFP_MAGIC;
213	compat_ulong_t size = VFP_STORAGE_SIZE;
214	compat_ulong_t fpscr, fpexc;
215	int err = 0;
216
217	/*
218	* Save the hardware registers to the fpsimd_state structure.
219	* Note that this also saves V16-31, which aren't visible
220	* in AArch32.
221	*/
222	fpsimd_save_state(fpsimd);
223
224	/* Place structure header on the stack */
225	__put_user_error(magic, &frame->magic, err);
226	__put_user_error(size, &frame->size, err);
227
228	/*
229	* Now copy the FP registers. Since the registers are packed,
230	* we can copy the prefix we want (V0-V15) as it is.
231	* FIXME: Won't work if big endian.
232	*/
233	err \|= __copy_to_user(&frame->ufp.fpregs, fpsimd->vregs,
234	sizeof(frame->ufp.fpregs));
235
236	/* Create an AArch32 fpscr from the fpsr and the fpcr. */
237	fpscr = (fpsimd->fpsr & VFP_FPSCR_STAT_MASK) \|
238	(fpsimd->fpcr & VFP_FPSCR_CTRL_MASK);
239	__put_user_error(fpscr, &frame->ufp.fpscr, err);
240
241	/*
242	* The exception register aren't available so we fake up a
243	* basic FPEXC and zero everything else.
244	*/
245	fpexc = (1 << 30);
246	__put_user_error(fpexc, &frame->ufp_exc.fpexc, err);
247	__put_user_error(0, &frame->ufp_exc.fpinst, err);
248	__put_user_error(0, &frame->ufp_exc.fpinst2, err);
249
250	return err ? -EFAULT : 0;
251	}
252
253	static int compat_restore_vfp_context(struct compat_vfp_sigframe __user *frame)
254	{
255	struct fpsimd_state fpsimd;
256	compat_ulong_t magic = VFP_MAGIC;
257	compat_ulong_t size = VFP_STORAGE_SIZE;
258	compat_ulong_t fpscr;
259	int err = 0;
260
261	__get_user_error(magic, &frame->magic, err);
262	__get_user_error(size, &frame->size, err);
263
264	if (err)
265	return -EFAULT;
266	if (magic != VFP_MAGIC \|\| size != VFP_STORAGE_SIZE)
267	return -EINVAL;
268
269	/*
270	* Copy the FP registers into the start of the fpsimd_state.
271	* FIXME: Won't work if big endian.
272	*/
273	err \|= __copy_from_user(fpsimd.vregs, frame->ufp.fpregs,
274	sizeof(frame->ufp.fpregs));
275
276	/* Extract the fpsr and the fpcr from the fpscr */
277	__get_user_error(fpscr, &frame->ufp.fpscr, err);
278	fpsimd.fpsr = fpscr & VFP_FPSCR_STAT_MASK;
279	fpsimd.fpcr = fpscr & VFP_FPSCR_CTRL_MASK;
280
281	/*
282	* We don't need to touch the exception register, so
283	* reload the hardware state.
284	*/
285	if (!err) {
286	preempt_disable();
287	fpsimd_load_state(&fpsimd);
288	preempt_enable();
289	}
290
291	return err ? -EFAULT : 0;
292	}
293
3dd681d9 WD	294	static int compat_restore_sigframe(struct pt_regs *regs,
	295	struct compat_sigframe __user *sf)
	296	{
	297	int err;
	298	sigset_t set;
	299	struct compat_aux_sigframe __user *aux;
	300
	301	err = get_sigset_t(&set, &sf->uc.uc_sigmask);
	302	if (err == 0) {
	303	sigdelsetmask(&set, ~_BLOCKABLE);
	304	set_current_blocked(&set);
	305	}
	306
	307	__get_user_error(regs->regs[0], &sf->uc.uc_mcontext.arm_r0, err);
	308	__get_user_error(regs->regs[1], &sf->uc.uc_mcontext.arm_r1, err);
	309	__get_user_error(regs->regs[2], &sf->uc.uc_mcontext.arm_r2, err);
	310	__get_user_error(regs->regs[3], &sf->uc.uc_mcontext.arm_r3, err);
	311	__get_user_error(regs->regs[4], &sf->uc.uc_mcontext.arm_r4, err);
	312	__get_user_error(regs->regs[5], &sf->uc.uc_mcontext.arm_r5, err);
	313	__get_user_error(regs->regs[6], &sf->uc.uc_mcontext.arm_r6, err);
	314	__get_user_error(regs->regs[7], &sf->uc.uc_mcontext.arm_r7, err);
	315	__get_user_error(regs->regs[8], &sf->uc.uc_mcontext.arm_r8, err);
	316	__get_user_error(regs->regs[9], &sf->uc.uc_mcontext.arm_r9, err);
	317	__get_user_error(regs->regs[10], &sf->uc.uc_mcontext.arm_r10, err);
	318	__get_user_error(regs->regs[11], &sf->uc.uc_mcontext.arm_fp, err);
	319	__get_user_error(regs->regs[12], &sf->uc.uc_mcontext.arm_ip, err);
	320	__get_user_error(regs->compat_sp, &sf->uc.uc_mcontext.arm_sp, err);
	321	__get_user_error(regs->compat_lr, &sf->uc.uc_mcontext.arm_lr, err);
	322	__get_user_error(regs->pc, &sf->uc.uc_mcontext.arm_pc, err);
	323	__get_user_error(regs->pstate, &sf->uc.uc_mcontext.arm_cpsr, err);
	324
	325	/*
	326	* Avoid compat_sys_sigreturn() restarting.
	327	*/
	328	regs->syscallno = ~0UL;
	329
	330	err \|= !valid_user_regs(&regs->user_regs);
	331
	332	aux = (struct compat_aux_sigframe __user *) sf->uc.uc_regspace;
	333	if (err == 0)
	334	err \|= compat_restore_vfp_context(&aux->vfp);
	335
	336	return err;
	337	}
	338
	339	asmlinkage int compat_sys_sigreturn(struct pt_regs *regs)
	340	{
	341	struct compat_sigframe __user *frame;
	342
	343	/* Always make any pending restarted system calls return -EINTR */
	344	current_thread_info()->restart_block.fn = do_no_restart_syscall;
	345
	346	/*
	347	* Since we stacked the signal on a 64-bit boundary,
	348	* then 'sp' should be word aligned here. If it's
	349	* not, then the user is trying to mess with us.
	350	*/
	351	if (regs->compat_sp & 7)
	352	goto badframe;
	353
	354	frame = (struct compat_sigframe __user *)regs->compat_sp;
	355
	356	if (!access_ok(VERIFY_READ, frame, sizeof (*frame)))
	357	goto badframe;
358
359	if (compat_restore_sigframe(regs, frame))
360	goto badframe;
361
362	return regs->regs[0];
363
364	badframe:
365	if (show_unhandled_signals)
366	pr_info_ratelimited("%s[%d]: bad frame in %s: pc=%08llx sp=%08llx\n",
367	current->comm, task_pid_nr(current), __func__,
368	regs->pc, regs->sp);
369	force_sig(SIGSEGV, current);
370	return 0;
371	}
372
373	asmlinkage int compat_sys_rt_sigreturn(struct pt_regs *regs)
374	{
375	struct compat_rt_sigframe __user *frame;
376
377	/* Always make any pending restarted system calls return -EINTR */
378	current_thread_info()->restart_block.fn = do_no_restart_syscall;
379
380	/*
381	* Since we stacked the signal on a 64-bit boundary,
382	* then 'sp' should be word aligned here. If it's
383	* not, then the user is trying to mess with us.
384	*/
385	if (regs->compat_sp & 7)
386	goto badframe;
387
388	frame = (struct compat_rt_sigframe __user *)regs->compat_sp;
389
390	if (!access_ok(VERIFY_READ, frame, sizeof (*frame)))
391	goto badframe;
392
393	if (compat_restore_sigframe(regs, &frame->sig))
394	goto badframe;
395
207bdae4	396	if (compat_restore_altstack(&frame->sig.uc.uc_stack))
3dd681d9 WD	397	goto badframe;
	398
	399	return regs->regs[0];
	400
	401	badframe:
	402	if (show_unhandled_signals)
	403	pr_info_ratelimited("%s[%d]: bad frame in %s: pc=%08llx sp=%08llx\n",
	404	current->comm, task_pid_nr(current), __func__,
	405	regs->pc, regs->sp);
	406	force_sig(SIGSEGV, current);
	407	return 0;
	408	}
	409
88a24cff WD	410	static void __user compat_get_sigframe(struct k_sigaction ka,
	411	struct pt_regs *regs,
	412	int framesize)
3dd681d9 WD	413	{
	414	compat_ulong_t sp = regs->compat_sp;
	415	void __user *frame;
	416
	417	/*
	418	* This is the X/Open sanctioned signal stack switching.
	419	*/
	420	if ((ka->sa.sa_flags & SA_ONSTACK) && !sas_ss_flags(sp))
	421	sp = current->sas_ss_sp + current->sas_ss_size;
	422
	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
	449	if (thumb) {
	450	spsr \|= COMPAT_PSR_T_BIT;
	451	spsr &= ~COMPAT_PSR_IT_MASK;
	452	} else {
	453	spsr &= ~COMPAT_PSR_T_BIT;
	454	}
	455
	456	if (ka->sa.sa_flags & SA_RESTORER) {
	457	retcode = ptr_to_compat(ka->sa.sa_restorer);
	458	} else {
	459	/* Set up sigreturn pointer */
	460	unsigned int idx = thumb << 1;
	461
	462	if (ka->sa.sa_flags & SA_SIGINFO)
	463	idx += 3;
	464
	465	retcode = AARCH32_VECTORS_BASE +
	466	AARCH32_KERN_SIGRET_CODE_OFFSET +
	467	(idx << 2) + thumb;
	468	}
	469
	470	regs->regs[0] = usig;
	471	regs->compat_sp = ptr_to_compat(frame);
	472	regs->compat_lr = retcode;
	473	regs->pc = handler;
	474	regs->pstate = spsr;
3dd681d9 WD	475	}
	476
	477	static int compat_setup_sigframe(struct compat_sigframe __user *sf,
	478	struct pt_regs regs, sigset_t set)
	479	{
	480	struct compat_aux_sigframe __user *aux;
	481	int err = 0;
	482
	483	__put_user_error(regs->regs[0], &sf->uc.uc_mcontext.arm_r0, err);
	484	__put_user_error(regs->regs[1], &sf->uc.uc_mcontext.arm_r1, err);
	485	__put_user_error(regs->regs[2], &sf->uc.uc_mcontext.arm_r2, err);
	486	__put_user_error(regs->regs[3], &sf->uc.uc_mcontext.arm_r3, err);
	487	__put_user_error(regs->regs[4], &sf->uc.uc_mcontext.arm_r4, err);
	488	__put_user_error(regs->regs[5], &sf->uc.uc_mcontext.arm_r5, err);
	489	__put_user_error(regs->regs[6], &sf->uc.uc_mcontext.arm_r6, err);
	490	__put_user_error(regs->regs[7], &sf->uc.uc_mcontext.arm_r7, err);
	491	__put_user_error(regs->regs[8], &sf->uc.uc_mcontext.arm_r8, err);
	492	__put_user_error(regs->regs[9], &sf->uc.uc_mcontext.arm_r9, err);
	493	__put_user_error(regs->regs[10], &sf->uc.uc_mcontext.arm_r10, err);
	494	__put_user_error(regs->regs[11], &sf->uc.uc_mcontext.arm_fp, err);
	495	__put_user_error(regs->regs[12], &sf->uc.uc_mcontext.arm_ip, err);
	496	__put_user_error(regs->compat_sp, &sf->uc.uc_mcontext.arm_sp, err);
	497	__put_user_error(regs->compat_lr, &sf->uc.uc_mcontext.arm_lr, err);
	498	__put_user_error(regs->pc, &sf->uc.uc_mcontext.arm_pc, err);
	499	__put_user_error(regs->pstate, &sf->uc.uc_mcontext.arm_cpsr, err);
	500
	501	__put_user_error((compat_ulong_t)0, &sf->uc.uc_mcontext.trap_no, err);
	502	__put_user_error((compat_ulong_t)0, &sf->uc.uc_mcontext.error_code, err);
	503	__put_user_error(current->thread.fault_address, &sf->uc.uc_mcontext.fault_address, err);
	504	__put_user_error(set->sig[0], &sf->uc.uc_mcontext.oldmask, err);
	505
	506	err \|= put_sigset_t(&sf->uc.uc_sigmask, set);
	507
	508	aux = (struct compat_aux_sigframe __user *) sf->uc.uc_regspace;
	509
	510	if (err == 0)
	511	err \|= compat_preserve_vfp_context(&aux->vfp);
	512	__put_user_error(0, &aux->end_magic, err);
	513
	514	return err;
	515	}
	516
	517	/*
	518	* 32-bit signal handling routines called from signal.c
	519	*/
	520	int compat_setup_rt_frame(int usig, struct k_sigaction ka, siginfo_t info,
	521	sigset_t set, struct pt_regs regs)
	522	{
	523	struct compat_rt_sigframe __user *frame;
3dd681d9 WD	524	int err = 0;
	525
	526	frame = compat_get_sigframe(ka, regs, sizeof(*frame));
	527
	528	if (!frame)
	529	return 1;
	530
	531	err \|= copy_siginfo_to_user32(&frame->info, info);
	532
	533	__put_user_error(0, &frame->sig.uc.uc_flags, err);
c0e01d5d	534	__put_user_error(0, &frame->sig.uc.uc_link, err);
3dd681d9	535
207bdae4	536	err \|= __compat_save_altstack(&frame->sig.uc.uc_stack, regs->compat_sp);
3dd681d9 WD	537
3dd681d9 WD	538	err \|= compat_setup_sigframe(&frame->sig, regs, set);
3dd681d9 WD	539
3dd681d9 WD	540	if (err == 0) {
060a18c7	541	compat_setup_return(regs, ka, frame->sig.retcode, frame, usig);
3dd681d9 WD	542	regs->regs[1] = (compat_ulong_t)(unsigned long)&frame->info;
	543	regs->regs[2] = (compat_ulong_t)(unsigned long)&frame->sig.uc;
	544	}
	545
	546	return err;
	547	}
	548
	549	int compat_setup_frame(int usig, struct k_sigaction ka, sigset_t set,
	550	struct pt_regs *regs)
	551	{
	552	struct compat_sigframe __user *frame;
	553	int err = 0;
	554
	555	frame = compat_get_sigframe(ka, regs, sizeof(*frame));
	556
	557	if (!frame)
	558	return 1;
	559
	560	__put_user_error(0x5ac3c35a, &frame->uc.uc_flags, err);
	561
	562	err \|= compat_setup_sigframe(frame, regs, set);
	563	if (err == 0)
060a18c7	564	compat_setup_return(regs, ka, frame->retcode, frame, usig);
3dd681d9 WD	565
	566	return err;
	567	}
	568
3dd681d9 WD	569	void compat_setup_restart_syscall(struct pt_regs *regs)
3dd681d9 WD	570	{
4ed27ecf	571	regs->regs[7] = __NR_compat_restart_syscall;
3dd681d9	572	}