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-rw-r--r--include/uapi/asm-generic/sembuf.h45
1 files changed, 45 insertions, 0 deletions
diff --git a/include/uapi/asm-generic/sembuf.h b/include/uapi/asm-generic/sembuf.h
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+++ b/include/uapi/asm-generic/sembuf.h
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+/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
+#ifndef __ASM_GENERIC_SEMBUF_H
+#define __ASM_GENERIC_SEMBUF_H
+
+#include <asm/bitsperlong.h>
+#include <asm/ipcbuf.h>
+
+/*
+ * The semid64_ds structure for x86 architecture.
+ * Note extra padding because this structure is passed back and forth
+ * between kernel and user space.
+ *
+ * semid64_ds was originally meant to be architecture specific, but
+ * everyone just ended up making identical copies without specific
+ * optimizations, so we may just as well all use the same one.
+ *
+ * 64 bit architectures use a 64-bit long time field here, while
+ * 32 bit architectures have a pair of unsigned long values.
+ *
+ * On big-endian systems, the padding is in the wrong place for
+ * historic reasons, so user space has to reconstruct a time_t
+ * value using
+ *
+ * user_semid_ds.sem_otime = kernel_semid64_ds.sem_otime +
+ * ((long long)kernel_semid64_ds.sem_otime_high << 32)
+ *
+ * Pad space is left for 2 miscellaneous 32-bit values
+ */
+struct semid64_ds {
+ struct ipc64_perm sem_perm; /* permissions .. see ipc.h */
+#if __BITS_PER_LONG == 64
+ long sem_otime; /* last semop time */
+ long sem_ctime; /* last change time */
+#else
+ unsigned long sem_otime; /* last semop time */
+ unsigned long sem_otime_high;
+ unsigned long sem_ctime; /* last change time */
+ unsigned long sem_ctime_high;
+#endif
+ unsigned long sem_nsems; /* no. of semaphores in array */
+ unsigned long __unused3;
+ unsigned long __unused4;
+};
+
+#endif /* __ASM_GENERIC_SEMBUF_H */