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>
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

View File

@@ -103,7 +103,7 @@
91 common madvise sys_madvise
92 common shmget sys_shmget
93 common shmat xtensa_shmat
94 common shmctl sys_shmctl
94 common shmctl sys_old_shmctl
95 common shmdt sys_shmdt
# Socket Operations
96 common socket sys_socket
@@ -177,12 +177,12 @@
161 common semtimedop sys_semtimedop
162 common semget sys_semget
163 common semop sys_semop
164 common semctl sys_semctl
164 common semctl sys_old_semctl
165 common available165 sys_ni_syscall
166 common msgget sys_msgget
167 common msgsnd sys_msgsnd
168 common msgrcv sys_msgrcv
169 common msgctl sys_msgctl
169 common msgctl sys_old_msgctl
170 common available170 sys_ni_syscall
# File System
171 common umount2 sys_umount