lib/muldi3.c


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/*
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * 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 the file COPYING, or write
 * to the Free Software Foundation, Inc.
 */

#include <linux/export.h>
#include <linux/libgcc.h>

#define W_TYPE_SIZE 32

#define __ll_B ((unsigned long) 1 << (W_TYPE_SIZE / 2))
#define __ll_lowpart(t) ((unsigned long) (t) & (__ll_B - 1))
#define __ll_highpart(t) ((unsigned long) (t) >> (W_TYPE_SIZE / 2))

/* If we still don't have umul_ppmm, define it using plain C.  */
#if !defined(umul_ppmm)
#define umul_ppmm(w1, w0, u, v)						\
	do {								\
		unsigned long __x0, __x1, __x2, __x3;			\
		unsigned short __ul, __vl, __uh, __vh;			\
									\
		__ul = __ll_lowpart(u);					\
		__uh = __ll_highpart(u);				\
		__vl = __ll_lowpart(v);					\
		__vh = __ll_highpart(v);				\
									\
		__x0 = (unsigned long) __ul * __vl;			\
		__x1 = (unsigned long) __ul * __vh;			\
		__x2 = (unsigned long) __uh * __vl;			\
		__x3 = (unsigned long) __uh * __vh;			\
									\
		__x1 += __ll_highpart(__x0); /* this can't give carry */\
		__x1 += __x2; /* but this indeed can */			\
		if (__x1 < __x2) /* did we get it? */			\
		__x3 += __ll_B; /* yes, add it in the proper pos */	\
									\
		(w1) = __x3 + __ll_highpart(__x1);			\
		(w0) = __ll_lowpart(__x1) * __ll_B + __ll_lowpart(__x0);\
	} while (0)
#endif

#if !defined(__umulsidi3)
#define __umulsidi3(u, v) ({				\
	DWunion __w;					\
	umul_ppmm(__w.s.high, __w.s.low, u, v);		\
	__w.ll;						\
	})
#endif

long long notrace __muldi3(long long u, long long v)
{
	const DWunion uu = {.ll = u};
	const DWunion vv = {.ll = v};
	DWunion w = {.ll = __umulsidi3(uu.s.low, vv.s.low)};

	w.s.high += ((unsigned long) uu.s.low * (unsigned long) vv.s.high
		+ (unsigned long) uu.s.high * (unsigned long) vv.s.low);

	return w.ll;
}
EXPORT_SYMBOL(__muldi3);
/*
 * linux/ipc/msgutil.c
 * Copyright (C) 1999, 2004 Manfred Spraul
 *
 * This file is released under GNU General Public Licence version 2 or
 * (at your option) any later version.
 *
 * See the file COPYING for more details.
 */

#include <linux/spinlock.h>
#include <linux/init.h>
#include <linux/security.h>
#include <linux/slab.h>
#include <linux/ipc.h>
#include <linux/msg.h>
#include <linux/ipc_namespace.h>
#include <linux/utsname.h>
#include <linux/proc_ns.h>
#include <linux/uaccess.h>

#include "util.h"

DEFINE_SPINLOCK(mq_lock);

/*
 * The next 2 defines are here bc this is the only file
 * compiled when either CONFIG_SYSVIPC and CONFIG_POSIX_MQUEUE
 * and not CONFIG_IPC_NS.
 */
struct ipc_namespace init_ipc_ns = {
	.count		= REFCOUNT_INIT(1),
	.user_ns = &init_user_ns,
	.ns.inum = PROC_IPC_INIT_INO,
#ifdef CONFIG_IPC_NS
	.ns.ops = &ipcns_operations,
#endif
};

struct msg_msgseg {
	struct msg_msgseg *next;
	/* the next part of the message follows immediately */
};

#define DATALEN_MSG	((size_t)PAGE_SIZE-sizeof(struct msg_msg))
#define DATALEN_SEG	((size_t)PAGE_SIZE-sizeof(struct msg_msgseg))


static struct msg_msg *alloc_msg(size_t len)
{
	struct msg_msg *msg;
	struct msg_msgseg **pseg;
	size_t alen;

	alen = min(len, DATALEN_MSG);
	msg = kmalloc(sizeof(*msg) + alen, GFP_KERNEL_ACCOUNT);
	if (msg == NULL)
		return NULL;

	msg->next = NULL;
	msg->security = NULL;

	len -= alen;
	pseg = &msg->next;
	while (len > 0) {
		struct msg_msgseg *seg;
		alen = min(len, DATALEN_SEG);
		seg = kmalloc(sizeof(*seg) + alen, GFP_KERNEL_ACCOUNT);
		if (seg == NULL)
			goto out_err;
		*pseg = seg;
		seg->next = NULL;
		pseg = &seg->next;
		len -= alen;
	}

	return msg;

out_err:
	free_msg(msg);
	return NULL;
}

struct msg_msg *load_msg(const void __user *src, size_t len)
{
	struct msg_msg *msg;
	struct msg_msgseg *seg;
	int err = -EFAULT;
	size_t alen;

	msg = alloc_msg(len);
	if (msg == NULL)
		return ERR_PTR(-ENOMEM);

	alen = min(len, DATALEN_MSG);
	if (copy_from_user(msg + 1, src, alen))
		goto out_err;

	for (seg = msg->next; seg != NULL; seg = seg->next) {
		len -= alen;
		src = (char __user *)src + alen;
		alen = min(len, DATALEN_SEG);
		if (copy_from_user(seg + 1, src, alen))
			goto out_err;
	}

	err = security_msg_msg_alloc(msg);
	if (err)
		goto out_err;

	return msg;

out_err:
	free_msg(msg);
	return ERR_PTR(err);
}
#ifdef CONFIG_CHECKPOINT_RESTORE
struct msg_msg *copy_msg(struct msg_msg *src, struct msg_msg *dst)
{
	struct msg_msgseg *dst_pseg, *src_pseg;
	size_t len = src->m_ts;
	size_t alen;

	if (src->m_ts > dst->m_ts)
		return ERR_PTR(-EINVAL);

	alen = min(len, DATALEN_MSG);
	memcpy(dst + 1, src + 1, alen);

	for (dst_pseg = dst->next, src_pseg = src->next;
	     src_pseg != NULL;
	     dst_pseg = dst_pseg->next, src_pseg = src_pseg->next) {

		len -= alen;
		alen = min(len, DATALEN_SEG);
		memcpy(dst_pseg + 1, src_pseg + 1, alen);
	}

	dst->m_type = src->m_type;
	dst->m_ts = src->m_ts;

	return dst;
}
#else
struct msg_msg *copy_msg(struct msg_msg *src, struct msg_msg *dst)
{
	return ERR_PTR(-ENOSYS);
}
#endif
int store_msg(void __user *dest, struct msg_msg *msg, size_t len)
{
	size_t alen;
	struct msg_msgseg *seg;

	alen = min(len, DATALEN_MSG);
	if (copy_to_user(dest, msg + 1, alen))
		return -1;

	for (seg = msg->next; seg != NULL; seg = seg->next) {
		len -= alen;
		dest = (char __user *)dest + alen;
		alen = min(len, DATALEN_SEG);
		if (copy_to_user(dest, seg + 1, alen))
			return -1;
	}
	return 0;
}

void free_msg(struct msg_msg *msg)
{
	struct msg_msgseg *seg;

	security_msg_msg_free(msg);

	seg = msg->next;
	kfree(msg);
	while (seg != NULL) {
		struct msg_msgseg *tmp = seg->next;
		kfree(seg);
		seg = tmp;
	}
}