ipc: rename old-style shmctl/semctl/msgctl syscalls

The behavior of these system calls is slightly different between
architectures, as determined by the CONFIG_ARCH_WANT_IPC_PARSE_VERSION
symbol. Most architectures that implement the split IPC syscalls don't set
that symbol and only get the modern version, but alpha, arm, microblaze,
mips-n32, mips-n64 and xtensa expect the caller to pass the IPC_64 flag.

For the architectures that so far only implement sys_ipc(), i.e. m68k,
mips-o32, powerpc, s390, sh, sparc, and x86-32, we want the new behavior
when adding the split syscalls, so we need to distinguish between the
two groups of architectures.

The method I picked for this distinction is to have a separate system call
entry point: sys_old_*ctl() now uses ipc_parse_version, while sys_*ctl()
does not. The system call tables of the five architectures are changed
accordingly.

As an additional benefit, we no longer need the configuration specific
definition for ipc_parse_version(), it always does the same thing now,
but simply won't get called on architectures with the modern interface.

A small downside is that on architectures that do set
ARCH_WANT_IPC_PARSE_VERSION, we now have an extra set of entry points
that are never called. They only add a few bytes of bloat, so it seems
better to keep them compared to adding yet another Kconfig symbol.
I considered adding new syscall numbers for the IPC_64 variants for
consistency, but decided against that for now.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>

1 files changed, 7 insertions, 14 deletions

diff --git a/ipc/util.h b/ipc/util.h
index d768fdbed515..e272be622ae7 100644
--- a/ipc/util.h
+++ b/ipc/util.h
@@ -160,10 +160,7 @@ static inline void ipc_update_pid(struct pid **pos, struct pid *pid)
 	}
 }
 
-#ifndef CONFIG_ARCH_WANT_IPC_PARSE_VERSION
-/* On IA-64, we always use the "64-bit version" of the IPC structures.  */
-# define ipc_parse_version(cmd)	IPC_64
-#else
+#ifdef CONFIG_ARCH_WANT_IPC_PARSE_VERSION
 int ipc_parse_version(int *cmd);
 #endif
 
@@ -246,13 +243,9 @@ int get_compat_ipc64_perm(struct ipc64_perm *,
 
 static inline int compat_ipc_parse_version(int *cmd)
 {
-#ifdef	CONFIG_ARCH_WANT_COMPAT_IPC_PARSE_VERSION
 	int version = *cmd & IPC_64;
 	*cmd &= ~IPC_64;
 	return version;
-#else
-	return IPC_64;
-#endif
 }
 #endif
 
@@ -261,29 +254,29 @@ long ksys_semtimedop(int semid, struct sembuf __user *tsops,
 		     unsigned int nsops,
 		     const struct __kernel_timespec __user *timeout);
 long ksys_semget(key_t key, int nsems, int semflg);
-long ksys_semctl(int semid, int semnum, int cmd, unsigned long arg);
+long ksys_old_semctl(int semid, int semnum, int cmd, unsigned long arg);
 long ksys_msgget(key_t key, int msgflg);
-long ksys_msgctl(int msqid, int cmd, struct msqid_ds __user *buf);
+long ksys_old_msgctl(int msqid, int cmd, struct msqid_ds __user *buf);
 long ksys_msgrcv(int msqid, struct msgbuf __user *msgp, size_t msgsz,
 		 long msgtyp, int msgflg);
 long ksys_msgsnd(int msqid, struct msgbuf __user *msgp, size_t msgsz,
 		 int msgflg);
 long ksys_shmget(key_t key, size_t size, int shmflg);
 long ksys_shmdt(char __user *shmaddr);
-long ksys_shmctl(int shmid, int cmd, struct shmid_ds __user *buf);
+long ksys_old_shmctl(int shmid, int cmd, struct shmid_ds __user *buf);
 
 /* for CONFIG_ARCH_WANT_OLD_COMPAT_IPC */
 long compat_ksys_semtimedop(int semid, struct sembuf __user *tsems,
 			    unsigned int nsops,
 			    const struct old_timespec32 __user *timeout);
 #ifdef CONFIG_COMPAT
-long compat_ksys_semctl(int semid, int semnum, int cmd, int arg);
-long compat_ksys_msgctl(int msqid, int cmd, void __user *uptr);
+long compat_ksys_old_semctl(int semid, int semnum, int cmd, int arg);
+long compat_ksys_old_msgctl(int msqid, int cmd, void __user *uptr);
 long compat_ksys_msgrcv(int msqid, compat_uptr_t msgp, compat_ssize_t msgsz,
 			compat_long_t msgtyp, int msgflg);
 long compat_ksys_msgsnd(int msqid, compat_uptr_t msgp,
 		       compat_ssize_t msgsz, int msgflg);
-long compat_ksys_shmctl(int shmid, int cmd, void __user *uptr);
+long compat_ksys_old_shmctl(int shmid, int cmd, void __user *uptr);
 #endif /* CONFIG_COMPAT */
 
 #endif