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author | Arnd Bergmann <arnd@arndb.de> | 2018-12-31 22:22:40 +0100 |
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committer | Arnd Bergmann <arnd@arndb.de> | 2019-01-25 17:22:50 +0100 |
commit | 275f22148e8720e84b180d9e0cdf8abfd69bac5b (patch) | |
tree | f7cb9810f8415904589d73a8d8f3c15b0bc70246 /ipc/shm.c | |
parent | sparc64: fix sparc_ipc type conversion (diff) | |
download | linux-275f22148e8720e84b180d9e0cdf8abfd69bac5b.tar.xz linux-275f22148e8720e84b180d9e0cdf8abfd69bac5b.zip |
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>
Diffstat (limited to 'ipc/shm.c')
-rw-r--r-- | ipc/shm.c | 40 |
1 files changed, 33 insertions, 7 deletions
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 /* |