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Linux kernel mirror (for testing) git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
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123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175176177178179180181182183184185186187188189190191192193// SPDX-License-Identifier: GPL-2.0-or-later/* * linux/ipc/msgutil.c * Copyright (C) 1999, 2004 Manfred Spraul */
#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 <linux/sched.h>#include <linux/nstree.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 = { .ns = NS_COMMON_INIT(init_ipc_ns), .user_ns = &init_user_ns,};
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 kmem_buckets *msg_buckets __ro_after_init;
static int __init init_msg_buckets(void){ msg_buckets = kmem_buckets_create("msg_msg", SLAB_ACCOUNT, sizeof(struct msg_msg), DATALEN_MSG, NULL);
return 0;}subsys_initcall(init_msg_buckets);
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 = kmem_buckets_alloc(msg_buckets, 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;
cond_resched();
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_RESTOREstruct 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;}#elsestruct msg_msg *copy_msg(struct msg_msg *src, struct msg_msg *dst){ return ERR_PTR(-ENOSYS);}#endifint 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;
cond_resched(); kfree(seg); seg = tmp; }}