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

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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>
This commit is contained in:
Arnd Bergmann
2018-12-31 22:22:40 +01:00
parent 73a66023c9
commit 275f22148e
14 changed files with 137 additions and 62 deletions
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21
ipc/util.h
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@@ -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