summaryrefslogtreecommitdiffstats
path: root/include/asm-generic/uaccess.h
diff options
context:
space:
mode:
Diffstat (limited to 'include/asm-generic/uaccess.h')
-rw-r--r--include/asm-generic/uaccess.h21
1 files changed, 14 insertions, 7 deletions
diff --git a/include/asm-generic/uaccess.h b/include/asm-generic/uaccess.h
index 1bfa602..6df9b07 100644
--- a/include/asm-generic/uaccess.h
+++ b/include/asm-generic/uaccess.h
@@ -72,6 +72,7 @@ struct exception_table_entry
/* Returns 0 if exception not found and fixup otherwise. */
extern unsigned long search_exception_table(unsigned long);
+
/*
* architectures with an MMU should override these two
*/
@@ -230,14 +231,18 @@ extern int __put_user_bad(void) __attribute__((noreturn));
might_fault(); \
access_ok(VERIFY_READ, __p, sizeof(*ptr)) ? \
__get_user((x), (__typeof__(*(ptr)) *)__p) : \
- -EFAULT; \
+ ((x) = (__typeof__(*(ptr)))0,-EFAULT); \
})
#ifndef __get_user_fn
static inline int __get_user_fn(size_t size, const void __user *ptr, void *x)
{
- size = __copy_from_user(x, ptr, size);
- return size ? -EFAULT : size;
+ size_t n = __copy_from_user(x, ptr, size);
+ if (unlikely(n)) {
+ memset(x + (size - n), 0, n);
+ return -EFAULT;
+ }
+ return 0;
}
#define __get_user_fn(sz, u, k) __get_user_fn(sz, u, k)
@@ -257,11 +262,13 @@ extern int __get_user_bad(void) __attribute__((noreturn));
static inline long copy_from_user(void *to,
const void __user * from, unsigned long n)
{
+ unsigned long res = n;
might_fault();
- if (access_ok(VERIFY_READ, from, n))
- return __copy_from_user(to, from, n);
- else
- return n;
+ if (likely(access_ok(VERIFY_READ, from, n)))
+ res = __copy_from_user(to, from, n);
+ if (unlikely(res))
+ memset(to + (n - res), 0, res);
+ return res;
}
static inline long copy_to_user(void __user *to,
OpenPOWER on IntegriCloud