summaryrefslogtreecommitdiffstats
path: root/kernel/ipc/msgutil.c
diff options
context:
space:
mode:
Diffstat (limited to 'kernel/ipc/msgutil.c')
-rw-r--r--kernel/ipc/msgutil.c185
1 files changed, 185 insertions, 0 deletions
diff --git a/kernel/ipc/msgutil.c b/kernel/ipc/msgutil.c
new file mode 100644
index 000000000..2b491590e
--- /dev/null
+++ b/kernel/ipc/msgutil.c
@@ -0,0 +1,185 @@
+/*
+ * 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 = ATOMIC_INIT(1),
+ .user_ns = &init_user_ns,
+ .ns.inum = PROC_IPC_INIT_INO,
+#ifdef CONFIG_IPC_NS
+ .ns.ops = &ipcns_operations,
+#endif
+};
+
+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 ((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);
+ 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);
+ 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;
+
+ BUG_ON(dst == NULL);
+ 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;
+ }
+}