[PATCH] more correct get_compat_timespec interface

From: Joe Korty <joe.korty@ccur.com>

The API for get_compat_timespec / put_compat_timespec is incorrect, it
forces a caller with const args to (incorrectly) cast.  The posix message
queue patch is one such caller.

include/linux/compat.h

@@ -44,8 +44,8 @@ typedef struct {
 } compat_sigset_t;
 
 extern int cp_compat_stat(struct kstat *, struct compat_stat *);
-extern int get_compat_timespec(struct timespec *, struct compat_timespec *);
-extern int put_compat_timespec(struct timespec *, struct compat_timespec *);
+extern int get_compat_timespec(struct timespec *, const struct compat_timespec *);
+extern int put_compat_timespec(struct timespec *, const struct compat_timespec *);
 
 struct compat_iovec {
 	compat_uptr_t	iov_base;

kernel/compat.c

@@ -22,14 +22,14 @@
 
 #include <asm/uaccess.h>
 
-int get_compat_timespec(struct timespec *ts, struct compat_timespec *cts)
+int get_compat_timespec(struct timespec *ts, const struct compat_timespec *cts)
 {
 	return (verify_area(VERIFY_READ, cts, sizeof(*cts)) ||
 			__get_user(ts->tv_sec, &cts->tv_sec) ||
 			__get_user(ts->tv_nsec, &cts->tv_nsec)) ? -EFAULT : 0;
 }
 
-int put_compat_timespec(struct timespec *ts, struct compat_timespec *cts)
+int put_compat_timespec(struct timespec *ts, const struct compat_timespec *cts)
 {
 	return (verify_area(VERIFY_WRITE, cts, sizeof(*cts)) ||
 			__put_user(ts->tv_sec, &cts->tv_sec) ||