ipc消息队列系统函数调用源码入口：如sys_msgsnd
#struct#user#null#up
路径：linux/ipc/syscall.c
/* 2 * sys_ipc() is the old de-multiplexer for the SysV IPC calls. 3 * 4 * This is really horribly ugly, and new architectures should just wire up 5 * the individual syscalls instead. 6 */ 7#include <linux/unistd.h> 8 9#ifdef __ARCH_WANT_SYS_IPC 10#include <linux/errno.h> 11#include <linux/ipc.h> 12#include <linux/shm.h> 13#include <linux/syscalls.h> 14#include <linux/uaccess.h> 15 16SYSCALL_DEFINE6(ipc, unsigned int, call, int, first, unsigned long, second, 17 unsigned long, third, void __user *, ptr, long, fifth) 18{ 19 int version, ret; 20 21 version = call >> 16; /* hack for backward compatibility */ 22 call &= 0xffff; 23 24 switch (call) { 25 case SEMOP: 26 return sys_semtimedop(first, (struct sembuf __user *)ptr, 27 second, NULL); 28 case SEMTIMEDOP: 29 return sys_semtimedop(first, (struct sembuf __user *)ptr, 30 second, 31 (const struct timespec __user *)fifth); 32 33 case SEMGET: 34 return sys_semget(first, second, third); 35 case SEMCTL: { 36 union semun fourth; 37 if (!ptr) 38 return -EINVAL; 39 if (get_user(fourth.__pad, (void __user * __user *) ptr)) 40 return -EFAULT; 41 return sys_semctl(first, second, third, fourth); 42 } 43 44 case MSGSND: 45 return sys_msgsnd(first, (struct msgbuf __user *) ptr, 46 second, third); 47 case MSGRCV: 48 switch (version) { 49 case 0: { 50 struct ipc_kludge tmp; 51 if (!ptr) 52 return -EINVAL; 53 54 if (copy_from_user(&tmp, 55 (struct ipc_kludge __user *) ptr, 56 sizeof(tmp))) 57 return -EFAULT; 58 return sys_msgrcv(first, tmp.msgp, second, 59 tmp.msgtyp, third); 60 } 61 default: 62 return sys_msgrcv(first, 63 (struct msgbuf __user *) ptr, 64 second, fifth, third); 65 } 66 case MSGGET: 67 return sys_msgget((key_t) first, second); 68 case MSGCTL: 69 return sys_msgctl(first, second, (struct msqid_ds __user *)ptr); 70 71 case SHMAT: 72 switch (version) { 73 default: { 74 unsigned long raddr; 75 ret = do_shmat(first, (char __user *)ptr, 76 second, &raddr); 77 if (ret) 78 return ret; 79 return put_user(raddr, (unsigned long __user *) third); 80 } 81 case 1: 82 /* 83 * This was the entry point for kernel-originating calls 84 * from iBCS2 in 2.2 days. 85 */ 86 return -EINVAL; 87 } 88 case SHMDT: 89 return sys_shmdt((char __user *)ptr); 90 case SHMGET: 91 return sys_shmget(first, second, third); 92 case SHMCTL: 93 return sys_shmctl(first, second, 94 (struct shmid_ds __user *) ptr); 95 default: 96 return -ENOSYS; 97 } 98} 99#endif 100