compat: Add helper functions to read/write struct timeval, timespec

Add helper functions to read and write struct timeval and struct
timespec from userspace.  We already had helper functions for reading
and writing struct compat_timespec; add a set of functions to do the
same with struct timeval, and add a second suite of functions which
can be sensitive to COMPAT_USE_64BIT_TIME and access either 32- or
64-bit time structures.

This also exports these helper functions to modules.

Rename the existing inlines for converting between struct
compat_timeval and native struct timespec so we can have a saner
naming convention for the exported functions.

Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>

1 files changed, 16 insertions, 0 deletions

diff --git a/include/linux/compat.h b/include/linux/compat.h
index 1be91c04824..a82e452bbdb 100644
--- a/include/linux/compat.h
+++ b/include/linux/compat.h
@@ -87,10 +87,26 @@ typedef struct {
         compat_sigset_word      sig[_COMPAT_NSIG_WORDS];
 } compat_sigset_t;
 
+/*
+ * These functions operate strictly on struct compat_time*
+ */
 extern int get_compat_timespec(struct timespec *,
                                const struct compat_timespec __user *);
 extern int put_compat_timespec(const struct timespec *,
                                struct compat_timespec __user *);
+extern int get_compat_timeval(struct timeval *,
+                              const struct compat_timeval __user *);
+extern int put_compat_timeval(const struct timeval *,
+                              struct compat_timeval __user *);
+/*
+ * These functions operate on 32- or 64-bit specs depending on
+ * COMPAT_USE_64BIT_TIME, hence the void user pointer arguments and the
+ * naming as compat_get/put_ rather than get/put_compat_.
+ */
+extern int compat_get_timespec(struct timespec *, const void __user *);
+extern int compat_put_timespec(const struct timespec *, void __user *);
+extern int compat_get_timeval(struct timeval *, const void __user *);
+extern int compat_put_timeval(const struct timeval *, void __user *);
 
 struct compat_iovec {
         compat_uptr_t   iov_base;