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>

5 files changed, 110 insertions, 41 deletions

diff --git a/ipc/msg.c b/ipc/msg.c
index 0833c6405915..8dec945fa030 100644
--- a/ipc/msg.c
+++ b/ipc/msg.c
@@ -567,9 +567,8 @@ out_unlock:
 	return err;
 }
 
-long ksys_msgctl(int msqid, int cmd, struct msqid_ds __user *buf)
+static long ksys_msgctl(int msqid, int cmd, struct msqid_ds __user *buf, int version)
 {
-	int version;
 	struct ipc_namespace *ns;
 	struct msqid64_ds msqid64;
 	int err;
@@ -577,7 +576,6 @@ long ksys_msgctl(int msqid, int cmd, struct msqid_ds __user *buf)
 	if (msqid < 0 || cmd < 0)
 		return -EINVAL;
 
-	version = ipc_parse_version(&cmd);
 	ns = current->nsproxy->ipc_ns;
 
 	switch (cmd) {
@@ -613,9 +611,23 @@ long ksys_msgctl(int msqid, int cmd, struct msqid_ds __user *buf)
 
 SYSCALL_DEFINE3(msgctl, int, msqid, int, cmd, struct msqid_ds __user *, buf)
 {
-	return ksys_msgctl(msqid, cmd, buf);
+	return ksys_msgctl(msqid, cmd, buf, IPC_64);
 }
 
+#ifdef CONFIG_ARCH_WANT_IPC_PARSE_VERSION
+long ksys_old_msgctl(int msqid, int cmd, struct msqid_ds __user *buf)
+{
+	int version = ipc_parse_version(&cmd);
+
+	return ksys_msgctl(msqid, cmd, buf, version);
+}
+
+SYSCALL_DEFINE3(old_msgctl, int, msqid, int, cmd, struct msqid_ds __user *, buf)
+{
+	return ksys_old_msgctl(msqid, cmd, buf);
+}
+#endif
+
 #ifdef CONFIG_COMPAT
 
 struct compat_msqid_ds {
@@ -689,12 +701,11 @@ static int copy_compat_msqid_to_user(void __user *buf, struct msqid64_ds *in,
 	}
 }
 
-long compat_ksys_msgctl(int msqid, int cmd, void __user *uptr)
+static long compat_ksys_msgctl(int msqid, int cmd, void __user *uptr, int version)
 {
 	struct ipc_namespace *ns;
 	int err;
 	struct msqid64_ds msqid64;
-	int version = compat_ipc_parse_version(&cmd);
 
 	ns = current->nsproxy->ipc_ns;
 
@@ -734,8 +745,22 @@ long compat_ksys_msgctl(int msqid, int cmd, void __user *uptr)
 
 COMPAT_SYSCALL_DEFINE3(msgctl, int, msqid, int, cmd, void __user *, uptr)
 {
-	return compat_ksys_msgctl(msqid, cmd, uptr);
+	return compat_ksys_msgctl(msqid, cmd, uptr, IPC_64);
 }
+
+#ifdef CONFIG_ARCH_WANT_COMPAT_IPC_PARSE_VERSION
+long compat_ksys_old_msgctl(int msqid, int cmd, void __user *uptr)
+{
+	int version = compat_ipc_parse_version(&cmd);
+
+	return compat_ksys_msgctl(msqid, cmd, uptr, version);
+}
+
+COMPAT_SYSCALL_DEFINE3(old_msgctl, int, msqid, int, cmd, void __user *, uptr)
+{
+	return compat_ksys_old_msgctl(msqid, cmd, uptr);
+}
+#endif
 #endif
 
 static int testmsg(struct msg_msg *msg, long type, int mode)
diff --git a/ipc/sem.c b/ipc/sem.c
index 745dc6187e84..d1efff3a81bb 100644
--- a/ipc/sem.c
+++ b/ipc/sem.c
@@ -1634,9 +1634,8 @@ out_up:
 	return err;
 }
 
-long ksys_semctl(int semid, int semnum, int cmd, unsigned long arg)
+static long ksys_semctl(int semid, int semnum, int cmd, unsigned long arg, int version)
 {
-	int version;
 	struct ipc_namespace *ns;
 	void __user *p = (void __user *)arg;
 	struct semid64_ds semid64;
@@ -1645,7 +1644,6 @@ long ksys_semctl(int semid, int semnum, int cmd, unsigned long arg)
 	if (semid < 0)
 		return -EINVAL;
 
-	version = ipc_parse_version(&cmd);
 	ns = current->nsproxy->ipc_ns;
 
 	switch (cmd) {
@@ -1691,9 +1689,23 @@ long ksys_semctl(int semid, int semnum, int cmd, unsigned long arg)
 
 SYSCALL_DEFINE4(semctl, int, semid, int, semnum, int, cmd, unsigned long, arg)
 {
-	return ksys_semctl(semid, semnum, cmd, arg);
+	return ksys_semctl(semid, semnum, cmd, arg, IPC_64);
 }
 
+#ifdef CONFIG_ARCH_WANT_IPC_PARSE_VERSION
+long ksys_old_semctl(int semid, int semnum, int cmd, unsigned long arg)
+{
+	int version = ipc_parse_version(&cmd);
+
+	return ksys_semctl(semid, semnum, cmd, arg, version);
+}
+
+SYSCALL_DEFINE4(old_semctl, int, semid, int, semnum, int, cmd, unsigned long, arg)
+{
+	return ksys_old_semctl(semid, semnum, cmd, arg);
+}
+#endif
+
 #ifdef CONFIG_COMPAT
 
 struct compat_semid_ds {
@@ -1744,12 +1756,11 @@ static int copy_compat_semid_to_user(void __user *buf, struct semid64_ds *in,
 	}
 }
 
-long compat_ksys_semctl(int semid, int semnum, int cmd, int arg)
+static long compat_ksys_semctl(int semid, int semnum, int cmd, int arg, int version)
 {
 	void __user *p = compat_ptr(arg);
 	struct ipc_namespace *ns;
 	struct semid64_ds semid64;
-	int version = compat_ipc_parse_version(&cmd);
 	int err;
 
 	ns = current->nsproxy->ipc_ns;
@@ -1792,8 +1803,22 @@ long compat_ksys_semctl(int semid, int semnum, int cmd, int arg)
 
 COMPAT_SYSCALL_DEFINE4(semctl, int, semid, int, semnum, int, cmd, int, arg)
 {
-	return compat_ksys_semctl(semid, semnum, cmd, arg);
+	return compat_ksys_semctl(semid, semnum, cmd, arg, IPC_64);
 }
+
+#ifdef CONFIG_ARCH_WANT_COMPAT_IPC_PARSE_VERSION
+long compat_ksys_old_semctl(int semid, int semnum, int cmd, int arg)
+{
+	int version = compat_ipc_parse_version(&cmd);
+
+	return compat_ksys_semctl(semid, semnum, cmd, arg, version);
+}
+
+COMPAT_SYSCALL_DEFINE4(old_semctl, int, semid, int, semnum, int, cmd, int, arg)
+{
+	return compat_ksys_old_semctl(semid, semnum, cmd, arg);
+}
+#endif
 #endif
 
 /* If the task doesn't already have a undo_list, then allocate one
diff --git a/ipc/shm.c b/ipc/shm.c
index 0842411cb0e9..ce1ca9f7c6e9 100644
--- a/ipc/shm.c
+++ b/ipc/shm.c
@@ -1137,16 +1137,15 @@ out_unlock1:
 	return err;
 }
 
-long ksys_shmctl(int shmid, int cmd, struct shmid_ds __user *buf)
+static long ksys_shmctl(int shmid, int cmd, struct shmid_ds __user *buf, int version)
 {
-	int err, version;
+	int err;
 	struct ipc_namespace *ns;
 	struct shmid64_ds sem64;
 
 	if (cmd < 0 || shmid < 0)
 		return -EINVAL;
 
-	version = ipc_parse_version(&cmd);
 	ns = current->nsproxy->ipc_ns;
 
 	switch (cmd) {
@@ -1194,8 +1193,22 @@ long ksys_shmctl(int shmid, int cmd, struct shmid_ds __user *buf)
 
 SYSCALL_DEFINE3(shmctl, int, shmid, int, cmd, struct shmid_ds __user *, buf)
 {
-	return ksys_shmctl(shmid, cmd, buf);
+	return ksys_shmctl(shmid, cmd, buf, IPC_64);
+}
+
+#ifdef CONFIG_ARCH_WANT_IPC_PARSE_VERSION
+long ksys_old_shmctl(int shmid, int cmd, struct shmid_ds __user *buf)
+{
+	int version = ipc_parse_version(&cmd);
+
+	return ksys_shmctl(shmid, cmd, buf, version);
+}
+
+SYSCALL_DEFINE3(old_shmctl, int, shmid, int, cmd, struct shmid_ds __user *, buf)
+{
+	return ksys_old_shmctl(shmid, cmd, buf);
 }
+#endif
 
 #ifdef CONFIG_COMPAT
 
@@ -1319,11 +1332,10 @@ static int copy_compat_shmid_from_user(struct shmid64_ds *out, void __user *buf,
 	}
 }
 
-long compat_ksys_shmctl(int shmid, int cmd, void __user *uptr)
+long compat_ksys_shmctl(int shmid, int cmd, void __user *uptr, int version)
 {
 	struct ipc_namespace *ns;
 	struct shmid64_ds sem64;
-	int version = compat_ipc_parse_version(&cmd);
 	int err;
 
 	ns = current->nsproxy->ipc_ns;
@@ -1378,8 +1390,22 @@ long compat_ksys_shmctl(int shmid, int cmd, void __user *uptr)
 
 COMPAT_SYSCALL_DEFINE3(shmctl, int, shmid, int, cmd, void __user *, uptr)
 {
-	return compat_ksys_shmctl(shmid, cmd, uptr);
+	return compat_ksys_shmctl(shmid, cmd, uptr, IPC_64);
 }
+
+#ifdef CONFIG_ARCH_WANT_COMPAT_IPC_PARSE_VERSION
+long compat_ksys_old_shmctl(int shmid, int cmd, void __user *uptr)
+{
+	int version = compat_ipc_parse_version(&cmd);
+
+	return compat_ksys_shmctl(shmid, cmd, uptr, version);
+}
+
+COMPAT_SYSCALL_DEFINE3(old_shmctl, int, shmid, int, cmd, void __user *, uptr)
+{
+	return compat_ksys_old_shmctl(shmid, cmd, uptr);
+}
+#endif
 #endif
 
 /*
diff --git a/ipc/syscall.c b/ipc/syscall.c
index 3cf8ad703a4d..581bdff4e7c5 100644
--- a/ipc/syscall.c
+++ b/ipc/syscall.c
@@ -47,7 +47,7 @@ int ksys_ipc(unsigned int call, int first, unsigned long second,
 			return -EINVAL;
 		if (get_user(arg, (unsigned long __user *) ptr))
 			return -EFAULT;
-		return ksys_semctl(first, second, third, arg);
+		return ksys_old_semctl(first, second, third, arg);
 	}
 
 	case MSGSND:
@@ -75,7 +75,7 @@ int ksys_ipc(unsigned int call, int first, unsigned long second,
 	case MSGGET:
 		return ksys_msgget((key_t) first, second);
 	case MSGCTL:
-		return ksys_msgctl(first, second,
+		return ksys_old_msgctl(first, second,
 				   (struct msqid_ds __user *)ptr);
 
 	case SHMAT:
@@ -100,7 +100,7 @@ int ksys_ipc(unsigned int call, int first, unsigned long second,
 	case SHMGET:
 		return ksys_shmget(first, second, third);
 	case SHMCTL:
-		return ksys_shmctl(first, second,
+		return ksys_old_shmctl(first, second,
 				   (struct shmid_ds __user *) ptr);
 	default:
 		return -ENOSYS;
@@ -152,7 +152,7 @@ int compat_ksys_ipc(u32 call, int first, int second,
 			return -EINVAL;
 		if (get_user(pad, (u32 __user *) compat_ptr(ptr)))
 			return -EFAULT;
-		return compat_ksys_semctl(first, second, third, pad);
+		return compat_ksys_old_semctl(first, second, third, pad);
 
 	case MSGSND:
 		return compat_ksys_msgsnd(first, ptr, second, third);
@@ -177,7 +177,7 @@ int compat_ksys_ipc(u32 call, int first, int second,
 	case MSGGET:
 		return ksys_msgget(first, second);
 	case MSGCTL:
-		return compat_ksys_msgctl(first, second, compat_ptr(ptr));
+		return compat_ksys_old_msgctl(first, second, compat_ptr(ptr));
 
 	case SHMAT: {
 		int err;
@@ -196,7 +196,7 @@ int compat_ksys_ipc(u32 call, int first, int second,
 	case SHMGET:
 		return ksys_shmget(first, (unsigned int)second, third);
 	case SHMCTL:
-		return compat_ksys_shmctl(first, second, compat_ptr(ptr));
+		return compat_ksys_old_shmctl(first, second, compat_ptr(ptr));
 	}
 
 	return -ENOSYS;
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