android_kernel_xiaomi_sm8350/ipc/msgutil.c
Serge E. Hallyn b515498f5b userns: add a user namespace owner of ipc ns
Changelog:
	Feb 15: Don't set new ipc->user_ns if we didn't create a new
		ipc_ns.
	Feb 23: Move extern declaration to ipc_namespace.h, and group
		fwd declarations at top.

Signed-off-by: Serge E. Hallyn <serge.hallyn@canonical.com>
Acked-by: "Eric W. Biederman" <ebiederm@xmission.com>
Acked-by: Daniel Lezcano <daniel.lezcano@free.fr>
Acked-by: David Howells <dhowells@redhat.com>
Cc: James Morris <jmorris@namei.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-03-23 19:47:07 -07:00

148 lines
2.8 KiB
C

/*
* 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/ipc_namespace.h>
#include <asm/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 = ATOMIC_INIT(1),
#ifdef CONFIG_POSIX_MQUEUE
.mq_queues_max = DFLT_QUEUESMAX,
.mq_msg_max = DFLT_MSGMAX,
.mq_msgsize_max = DFLT_MSGSIZEMAX,
#endif
.user_ns = &init_user_ns,
};
atomic_t nr_ipc_ns = ATOMIC_INIT(1);
struct msg_msgseg {
struct msg_msgseg* next;
/* the next part of the message follows immediately */
};
#define DATALEN_MSG (PAGE_SIZE-sizeof(struct msg_msg))
#define DATALEN_SEG (PAGE_SIZE-sizeof(struct msg_msgseg))
struct msg_msg *load_msg(const void __user *src, int len)
{
struct msg_msg *msg;
struct msg_msgseg **pseg;
int err;
int alen;
alen = len;
if (alen > DATALEN_MSG)
alen = DATALEN_MSG;
msg = kmalloc(sizeof(*msg) + alen, GFP_KERNEL);
if (msg == NULL)
return ERR_PTR(-ENOMEM);
msg->next = NULL;
msg->security = NULL;
if (copy_from_user(msg + 1, src, alen)) {
err = -EFAULT;
goto out_err;
}
len -= alen;
src = ((char __user *)src) + alen;
pseg = &msg->next;
while (len > 0) {
struct msg_msgseg *seg;
alen = len;
if (alen > DATALEN_SEG)
alen = DATALEN_SEG;
seg = kmalloc(sizeof(*seg) + alen,
GFP_KERNEL);
if (seg == NULL) {
err = -ENOMEM;
goto out_err;
}
*pseg = seg;
seg->next = NULL;
if (copy_from_user(seg + 1, src, alen)) {
err = -EFAULT;
goto out_err;
}
pseg = &seg->next;
len -= alen;
src = ((char __user *)src) + alen;
}
err = security_msg_msg_alloc(msg);
if (err)
goto out_err;
return msg;
out_err:
free_msg(msg);
return ERR_PTR(err);
}
int store_msg(void __user *dest, struct msg_msg *msg, int len)
{
int alen;
struct msg_msgseg *seg;
alen = len;
if (alen > DATALEN_MSG)
alen = DATALEN_MSG;
if (copy_to_user(dest, msg + 1, alen))
return -1;
len -= alen;
dest = ((char __user *)dest) + alen;
seg = msg->next;
while (len > 0) {
alen = len;
if (alen > DATALEN_SEG)
alen = DATALEN_SEG;
if (copy_to_user(dest, seg + 1, alen))
return -1;
len -= alen;
dest = ((char __user *)dest) + alen;
seg = seg->next;
}
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;
}
}