summaryrefslogtreecommitdiff
path: root/arch/x86/include/asm/shmbuf.h
diff options
context:
space:
mode:
Diffstat (limited to 'arch/x86/include/asm/shmbuf.h')
-rw-r--r--arch/x86/include/asm/shmbuf.h28
1 files changed, 18 insertions, 10 deletions
diff --git a/arch/x86/include/asm/shmbuf.h b/arch/x86/include/asm/shmbuf.h
index b51413b74971..5768fa60ac82 100644
--- a/arch/x86/include/asm/shmbuf.h
+++ b/arch/x86/include/asm/shmbuf.h
@@ -1,32 +1,40 @@
-#ifndef _ASM_X86_SHMBUF_H
-#define _ASM_X86_SHMBUF_H
+#ifndef __ASM_GENERIC_SHMBUF_H
+#define __ASM_GENERIC_SHMBUF_H
+
+#include <asm/bitsperlong.h>
/*
* The shmid64_ds structure for x86 architecture.
* Note extra padding because this structure is passed back and forth
* between kernel and user space.
*
- * Pad space on 32 bit is left for:
+ * shmid64_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 typically define a 64 bit __kernel_time_t,
+ * so they do not need the first two padding words.
+ * On big-endian systems, the padding is in the wrong place.
+ *
+ *
+ * Pad space is left for:
* - 64-bit time_t to solve y2038 problem
* - 2 miscellaneous 32-bit values
- *
- * Pad space on 64 bit is left for:
- * - 2 miscellaneous 64-bit values
*/
struct shmid64_ds {
struct ipc64_perm shm_perm; /* operation perms */
size_t shm_segsz; /* size of segment (bytes) */
__kernel_time_t shm_atime; /* last attach time */
-#ifdef __i386__
+#if __BITS_PER_LONG != 64
unsigned long __unused1;
#endif
__kernel_time_t shm_dtime; /* last detach time */
-#ifdef __i386__
+#if __BITS_PER_LONG != 64
unsigned long __unused2;
#endif
__kernel_time_t shm_ctime; /* last change time */
-#ifdef __i386__
+#if __BITS_PER_LONG != 64
unsigned long __unused3;
#endif
__kernel_pid_t shm_cpid; /* pid of creator */
@@ -48,4 +56,4 @@ struct shminfo64 {
unsigned long __unused4;
};
-#endif /* _ASM_X86_SHMBUF_H */
+#endif /* __ASM_GENERIC_SHMBUF_H */