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authorArnd Bergmann <arnd@arndb.de>2018-12-31 22:22:40 +0100
committerArnd Bergmann <arnd@arndb.de>2019-01-25 17:22:50 +0100
commit275f22148e8720e84b180d9e0cdf8abfd69bac5b (patch)
treef7cb9810f8415904589d73a8d8f3c15b0bc70246 /kernel/sys_ni.c
parent73a66023c937ef258f2aa340cdb53ae7d8b1d47c (diff)
downloadlinux-275f22148e8720e84b180d9e0cdf8abfd69bac5b.tar.gz
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 'kernel/sys_ni.c')
-rw-r--r--kernel/sys_ni.c3
1 files changed, 3 insertions, 0 deletions
diff --git a/kernel/sys_ni.c b/kernel/sys_ni.c
index bc934f31ab10..ce04431a40d1 100644
--- a/kernel/sys_ni.c
+++ b/kernel/sys_ni.c
@@ -197,6 +197,7 @@ COND_SYSCALL_COMPAT(mq_getsetattr);
 
 /* ipc/msg.c */
 COND_SYSCALL(msgget);
+COND_SYSCALL(old_msgctl);
 COND_SYSCALL(msgctl);
 COND_SYSCALL_COMPAT(msgctl);
 COND_SYSCALL(msgrcv);
@@ -206,6 +207,7 @@ COND_SYSCALL_COMPAT(msgsnd);
 
 /* ipc/sem.c */
 COND_SYSCALL(semget);
+COND_SYSCALL(old_semctl);
 COND_SYSCALL(semctl);
 COND_SYSCALL_COMPAT(semctl);
 COND_SYSCALL(semtimedop);
@@ -214,6 +216,7 @@ COND_SYSCALL(semop);
 
 /* ipc/shm.c */
 COND_SYSCALL(shmget);
+COND_SYSCALL(old_shmctl);
 COND_SYSCALL(shmctl);
 COND_SYSCALL_COMPAT(shmctl);
 COND_SYSCALL(shmat);