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, 3 insertions, 0 deletions

diff --git a/include/linux/syscalls.h b/include/linux/syscalls.h
index fb63045a0fb6..938d8908b9e0 100644
--- a/include/linux/syscalls.h
+++ b/include/linux/syscalls.h
@@ -717,6 +717,7 @@ asmlinkage long sys_mq_getsetattr(mqd_t mqdes, const struct mq_attr __user *mqst
 
 /* ipc/msg.c */
 asmlinkage long sys_msgget(key_t key, int msgflg);
+asmlinkage long sys_old_msgctl(int msqid, int cmd, struct msqid_ds __user *buf);
 asmlinkage long sys_msgctl(int msqid, int cmd, struct msqid_ds __user *buf);
 asmlinkage long sys_msgrcv(int msqid, struct msgbuf __user *msgp,
 				size_t msgsz, long msgtyp, int msgflg);
@@ -726,6 +727,7 @@ asmlinkage long sys_msgsnd(int msqid, struct msgbuf __user *msgp,
 /* ipc/sem.c */
 asmlinkage long sys_semget(key_t key, int nsems, int semflg);
 asmlinkage long sys_semctl(int semid, int semnum, int cmd, unsigned long arg);
+asmlinkage long sys_old_semctl(int semid, int semnum, int cmd, unsigned long arg);
 asmlinkage long sys_semtimedop(int semid, struct sembuf __user *sops,
 				unsigned nsops,
 				const struct __kernel_timespec __user *timeout);
@@ -734,6 +736,7 @@ asmlinkage long sys_semop(int semid, struct sembuf __user *sops,
 
 /* ipc/shm.c */
 asmlinkage long sys_shmget(key_t key, size_t size, int flag);
+asmlinkage long sys_old_shmctl(int shmid, int cmd, struct shmid_ds __user *buf);
 asmlinkage long sys_shmctl(int shmid, int cmd, struct shmid_ds __user *buf);
 asmlinkage long sys_shmat(int shmid, char __user *shmaddr, int shmflg);
 asmlinkage long sys_shmdt(char __user *shmaddr);