IPC之msg.c源码解读

// SPDX-License-Identifier: GPL-2.0
/*
 * linux/ipc/msg.c
 * Copyright (C) 1992 Krishna Balasubramanian
 *
 * Removed all the remaining kerneld mess
 * Catch the -EFAULT stuff properly
 * Use GFP_KERNEL for messages as in 1.2
 * Fixed up the unchecked user space derefs
 * Copyright (C) 1998 Alan Cox & Andi Kleen
 *
 * /proc/sysvipc/msg support (c) 1999 Dragos Acostachioaie <// SPDX-License-Identifier: GPL-2.0
/*
 * li