Include linux/types.h and asm/msgbuf.h and use __kernel_size_t instead
of size_t.

Fixes userspace compilation errors like:

error: field ‘shm_perm’ has incomplete type
struct ipc64_perm shm_perm; /* operation perms */
error: unknown type name ‘size_t’
error: unknown type name ‘__kernel_time_t’

Signed-off-by: Mikko Rapeli <redacted>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Cc: H.J. Lu <redacted>
Cc: H. Peter Anvin <hpa@zytor.com>
---
 include/uapi/asm-generic/shmbuf.h | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/include/uapi/asm-generic/shmbuf.h b/include/uapi/asm-generic/shmbuf.h
index 7e9fb2f0853b..ae867ad1e5e4 100644
--- a/include/uapi/asm-generic/shmbuf.h
+++ b/include/uapi/asm-generic/shmbuf.h

@@ -1,7 +1,9 @@
 #ifndef __ASM_GENERIC_SHMBUF_H
 #define __ASM_GENERIC_SHMBUF_H
 
+#include <linux/types.h>
 #include <asm/bitsperlong.h>
+#include <asm/msgbuf.h>
 
 /*
  * The shmid64_ds structure for x86 architecture.

@@ -24,7 +26,7 @@
 
 struct shmid64_ds {
 	struct ipc64_perm	shm_perm;	/* operation perms */
-	size_t			shm_segsz;	/* size of segment (bytes) */
+	__kernel_size_t		shm_segsz;	/* size of segment (bytes) */
 	__kernel_time_t		shm_atime;	/* last attach time */
 #if __BITS_PER_LONG != 64
 	unsigned long		__unused1;