[PATCH v3 01/17] Add __ASSUME_SYSVIPC_SYSCALL for Linux

[Adhemerval Zanella <adhemerval dot zanella at linaro dot org>]

On current minimum supported kernels, the SysV IPC on Linux is provided
by either the ipc syscalls or correspondent wire syscalls.  Also, for
architectures that supports wire syscalls all syscalls are supported
in a set (msgct, msgrcv, msgsnd, msgget, semctl, semget, semop, semtimedop,
shmctl, shmat, shmget, shmdt).

The architectures that only supports ipc syscall are:

  - i386, m68k, microblaze, mips32, powerpc (powerpc32, powerpc64, and
    powerpc64le), s390 (32 and 64 bits), sh, sparc32, and sparc64.

And the architectures that only supports wired syscalls are:

  - aarch64, alpha, hppa, ia64, mips64, mips64n32, nios2, tile
    (tilepro, tilegx, and tilegx64), and x86_64

Also arm is the only one that supports both wire syscalls and the
ipc, although the ipc one is deprecated.

This patch adds a new define, __ASSUME_SYSVIPC_SYSCALL, that wired
syscalls are supported on the system and the general idea is to use
it where possible.

I also checked the syscall table for all architectures on Linux 4.9
and there is no change on described support for Linux 2.6.32/3.2.

	* sysdeps/unix/sysv/linux/kernel-features.h
	(__ASSUME_SYSVIPC_SYSCALL): New define.
	* sysdeps/unix/sysv/linux/i386/kernel-features.h
	(__ASSUME_SYSVIPC_SYSCALL): Undef.
	* sysdeps/unix/sysv/linux/m68k/kernel-features.h
	(__ASSUME_SYSVIPC_SYSCALL): Likewise.
	* sysdeps/unix/sysv/linux/mips/kernel-features.h
	(__ASSUME_SYSVIPC_SYSCALL): Likewise.
	* sysdeps/unix/sysv/linux/powerpc/kernel-features.h
	(__ASSUME_SYSVIPC_SYSCALL): Likewise.
	* sysdeps/unix/sysv/linux/s390/kernel-features.h
	(__ASSUME_SYSVIPC_SYSCALL): Likewise.
	* sysdeps/unix/sysv/linux/sh/kernel-features.h
	(__ASSUME_SYSVIPC_SYSCALL): Likewise.
	* sysdeps/unix/sysv/linux/sparc/kernel-features.h
	(__ASSUME_SYSVIPC_SYSCALL): Likewise.
---
 ChangeLog                                         | 19 +++++++++++++++++++
 sysdeps/unix/sysv/linux/i386/kernel-features.h    |  3 +++
 sysdeps/unix/sysv/linux/kernel-features.h         |  4 ++++
 sysdeps/unix/sysv/linux/m68k/kernel-features.h    |  3 +++
 sysdeps/unix/sysv/linux/mips/kernel-features.h    |  2 ++
 sysdeps/unix/sysv/linux/powerpc/kernel-features.h |  3 +++
 sysdeps/unix/sysv/linux/s390/kernel-features.h    |  3 +++
 sysdeps/unix/sysv/linux/sh/kernel-features.h      |  3 +++
 sysdeps/unix/sysv/linux/sparc/kernel-features.h   |  3 +++
 9 files changed, 43 insertions(+)

diff --git a/sysdeps/unix/sysv/linux/i386/kernel-features.h b/sysdeps/unix/sysv/linux/i386/kernel-features.h
index 148963c..3da13d4 100644
--- a/sysdeps/unix/sysv/linux/i386/kernel-features.h
+++ b/sysdeps/unix/sysv/linux/i386/kernel-features.h
@@ -52,3 +52,6 @@
 # undef __ASSUME_SENDMSG_SYSCALL
 # undef __ASSUME_RECVMSG_SYSCALL
 #endif
+
+/* i686 only supports ipc syscall.  */
+#undef __ASSUME_SYSVIPC_SYSCALL
diff --git a/sysdeps/unix/sysv/linux/kernel-features.h b/sysdeps/unix/sysv/linux/kernel-features.h
index 1d3b554..cb0bc28 100644
--- a/sysdeps/unix/sysv/linux/kernel-features.h
+++ b/sysdeps/unix/sysv/linux/kernel-features.h
@@ -147,3 +147,7 @@
    separate syscalls were only added later.  */
 #define __ASSUME_SENDMSG_SYSCALL	1
 #define __ASSUME_RECVMSG_SYSCALL	1
+
+/* Support for SysV IPC through wired syscalls.  All supported architectures
+   either support ipc syscall and/or all the ipc correspondent syscalls.  */
+#define __ASSUME_SYSVIPC_SYSCALL	1
diff --git a/sysdeps/unix/sysv/linux/m68k/kernel-features.h b/sysdeps/unix/sysv/linux/m68k/kernel-features.h
index 46ec601..f0fd7ce 100644
--- a/sysdeps/unix/sysv/linux/m68k/kernel-features.h
+++ b/sysdeps/unix/sysv/linux/m68k/kernel-features.h
@@ -54,3 +54,6 @@
 # undef __ASSUME_REQUEUE_PI
 # undef __ASSUME_SET_ROBUST_LIST
 #endif
+
+/* m68k only supports ipc syscall.  */
+#undef __ASSUME_SYSVIPC_SYSCALL
diff --git a/sysdeps/unix/sysv/linux/mips/kernel-features.h b/sysdeps/unix/sysv/linux/mips/kernel-features.h
index b486d90..5e88c8e 100644
--- a/sysdeps/unix/sysv/linux/mips/kernel-features.h
+++ b/sysdeps/unix/sysv/linux/mips/kernel-features.h
@@ -32,6 +32,8 @@
    pairs to start with an even-number register.  */
 #if _MIPS_SIM == _ABIO32
 # define __ASSUME_ALIGNED_REGISTER_PAIRS	1
+/* mips32 only supports ipc syscall.  */
+# undef __ASSUME_SYSVIPC_SYSCALL
 #endif
 
 /* Define that mips64-n32 is a ILP32 ABI to set the correct interface to
diff --git a/sysdeps/unix/sysv/linux/powerpc/kernel-features.h b/sysdeps/unix/sysv/linux/powerpc/kernel-features.h
index 42a53f2..a81caf3 100644
--- a/sysdeps/unix/sysv/linux/powerpc/kernel-features.h
+++ b/sysdeps/unix/sysv/linux/powerpc/kernel-features.h
@@ -52,3 +52,6 @@
 #endif
 
 #include_next <kernel-features.h>
+
+/* powerpc only supports ipc syscall.  */
+#undef __ASSUME_SYSVIPC_SYSCALL
diff --git a/sysdeps/unix/sysv/linux/s390/kernel-features.h b/sysdeps/unix/sysv/linux/s390/kernel-features.h
index b3edee4..652436b 100644
--- a/sysdeps/unix/sysv/linux/s390/kernel-features.h
+++ b/sysdeps/unix/sysv/linux/s390/kernel-features.h
@@ -48,3 +48,6 @@
 # undef __ASSUME_SENDMSG_SYSCALL
 # undef __ASSUME_RECVMSG_SYSCALL
 #endif
+
+/* s390 only supports ipc syscall.  */
+#undef __ASSUME_SYSVIPC_SYSCALL
diff --git a/sysdeps/unix/sysv/linux/sh/kernel-features.h b/sysdeps/unix/sysv/linux/sh/kernel-features.h
index ea4fdbc..f6175f7 100644
--- a/sysdeps/unix/sysv/linux/sh/kernel-features.h
+++ b/sysdeps/unix/sysv/linux/sh/kernel-features.h
@@ -50,3 +50,6 @@
    the kernel interface for p{read,write}64 adds a dummy long argument
    before the offset.  */
 #define __ASSUME_PRW_DUMMY_ARG	1
+
+/* sh only supports ipc syscall.  */
+#undef __ASSUME_SYSVIPC_SYSCALL
diff --git a/sysdeps/unix/sysv/linux/sparc/kernel-features.h b/sysdeps/unix/sysv/linux/sparc/kernel-features.h
index 69c9c7c..20578bb 100644
--- a/sysdeps/unix/sysv/linux/sparc/kernel-features.h
+++ b/sysdeps/unix/sysv/linux/sparc/kernel-features.h
@@ -37,3 +37,6 @@
 # undef __ASSUME_REQUEUE_PI
 # undef __ASSUME_SET_ROBUST_LIST
 #endif
+
+/* sparc only supports ipc syscall.  */
+#undef __ASSUME_SYSVIPC_SYSCALL
-- 
2.7.4