ipc: prefer SYS_ipc when it is defined

Linux v5.1 introduced ipc syscalls on targets where previously only
SYS_ipc was available, change the logic such that the ipc code keeps
using SYS_ipc which works backward compatibly on older kernels.

This changes behaviour on microblaze which had both mechanisms, now
SYS_ipc will be used instead of separate syscalls.

src/ipc/msgctl.c

@@ -17,7 +17,7 @@ int msgctl(int q, int cmd, struct msqid_ds *buf)
 		buf = &tmp;
 	}
 #endif
-#ifdef SYS_msgctl
+#ifndef SYS_ipc
 	int r = __syscall(SYS_msgctl, q, cmd | IPC_64, buf);
 #else
 	int r = __syscall(SYS_ipc, IPCOP_msgctl, q, cmd | IPC_64, 0, buf, 0);

src/ipc/msgget.c

@@ -4,7 +4,7 @@
 
 int msgget(key_t k, int flag)
 {
-#ifdef SYS_msgget
+#ifndef SYS_ipc
 	return syscall(SYS_msgget, k, flag);
 #else
 	return syscall(SYS_ipc, IPCOP_msgget, k, flag);

src/ipc/msgrcv.c

@@ -4,7 +4,7 @@
 
 ssize_t msgrcv(int q, void *m, size_t len, long type, int flag)
 {
-#ifdef SYS_msgrcv
+#ifndef SYS_ipc
 	return syscall_cp(SYS_msgrcv, q, m, len, type, flag);
 #else
 	return syscall_cp(SYS_ipc, IPCOP_msgrcv, q, len, flag, ((long[]){ (long)m, type }));

src/ipc/msgsnd.c

@@ -4,7 +4,7 @@
 
 int msgsnd(int q, const void *m, size_t len, int flag)
 {
-#ifdef SYS_msgsnd
+#ifndef SYS_ipc
 	return syscall_cp(SYS_msgsnd, q, m, len, flag);
 #else
 	return syscall_cp(SYS_ipc, IPCOP_msgsnd, q, len, flag, m);

src/ipc/semctl.c

@@ -33,7 +33,7 @@ int semctl(int id, int num, int cmd, ...)
 		arg.buf = &tmp;
 	}
 #endif
-#ifdef SYS_semctl
+#ifndef SYS_ipc
 	int r = __syscall(SYS_semctl, id, num, cmd | IPC_64, arg.buf);
 #else
 	int r = __syscall(SYS_ipc, IPCOP_semctl, id, num, cmd | IPC_64, &arg.buf);

src/ipc/semget.c

@@ -11,7 +11,7 @@ int semget(key_t key, int n, int fl)
 	 * n fits in the correct (per POSIX) userspace type, so
 	 * we have to check here. */
 	if (n > USHRT_MAX) return __syscall_ret(-EINVAL);
-#ifdef SYS_semget
+#ifndef SYS_ipc
 	return syscall(SYS_semget, key, n, fl);
 #else
 	return syscall(SYS_ipc, IPCOP_semget, key, n, fl);

src/ipc/semop.c

@@ -4,7 +4,7 @@
 
 int semop(int id, struct sembuf *buf, size_t n)
 {
-#ifdef SYS_semop
+#ifndef SYS_ipc
 	return syscall(SYS_semop, id, buf, n);
 #else
 	return syscall(SYS_ipc, IPCOP_semop, id, n, 0, buf);

src/ipc/semtimedop.c

@@ -5,7 +5,7 @@
 
 int semtimedop(int id, struct sembuf *buf, size_t n, const struct timespec *ts)
 {
-#ifdef SYS_semtimedop
+#ifndef SYS_ipc
 	return syscall(SYS_semtimedop, id, buf, n, ts);
 #else
 	return syscall(SYS_ipc, IPCOP_semtimedop, id, n, 0, buf, ts);

src/ipc/shmat.c

@@ -2,7 +2,7 @@
 #include "syscall.h"
 #include "ipc.h"
 
-#ifdef SYS_shmat
+#ifndef SYS_ipc
 void *shmat(int id, const void *addr, int flag)
 {
 	return (void *)syscall(SYS_shmat, id, addr, flag);

src/ipc/shmctl.c

@@ -17,7 +17,7 @@ int shmctl(int id, int cmd, struct shmid_ds *buf)
 		buf = &tmp;
 	}
 #endif
-#ifdef SYS_shmctl
+#ifndef SYS_ipc
 	int r = __syscall(SYS_shmctl, id, cmd | IPC_64, buf);
 #else
 	int r = __syscall(SYS_ipc, IPCOP_shmctl, id, cmd | IPC_64, 0, buf, 0);

src/ipc/shmdt.c

@@ -4,7 +4,7 @@
 
 int shmdt(const void *addr)
 {
-#ifdef SYS_shmdt
+#ifndef SYS_ipc
 	return syscall(SYS_shmdt, addr);
 #else
 	return syscall(SYS_ipc, IPCOP_shmdt, 0, 0, 0, addr);

src/ipc/shmget.c

@@ -6,7 +6,7 @@
 int shmget(key_t key, size_t size, int flag)
 {
 	if (size > PTRDIFF_MAX) size = SIZE_MAX;
-#ifdef SYS_shmget
+#ifndef SYS_ipc
 	return syscall(SYS_shmget, key, size, flag);
 #else
 	return syscall(SYS_ipc, IPCOP_shmget, key, size, flag);