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Diffstat (limited to 'arch/um/include/um_uaccess.h')
-rw-r--r--arch/um/include/um_uaccess.h19
1 files changed, 18 insertions, 1 deletions
diff --git a/arch/um/include/um_uaccess.h b/arch/um/include/um_uaccess.h
index 84c0868..f8760a3 100644
--- a/arch/um/include/um_uaccess.h
+++ b/arch/um/include/um_uaccess.h
@@ -17,8 +17,25 @@
#include "uaccess-skas.h"
#endif
+#define __under_task_size(addr, size) \
+ (((unsigned long) (addr) < TASK_SIZE) && \
+ (((unsigned long) (addr) + (size)) < TASK_SIZE))
+
+#define __access_ok_vsyscall(type, addr, size) \
+ ((type == VERIFY_READ) && \
+ ((unsigned long) (addr) >= FIXADDR_USER_START) && \
+ ((unsigned long) (addr) + (size) <= FIXADDR_USER_END) && \
+ ((unsigned long) (addr) + (size) >= (unsigned long)(addr)))
+
+#define __addr_range_nowrap(addr, size) \
+ ((unsigned long) (addr) <= ((unsigned long) (addr) + (size)))
+
#define access_ok(type, addr, size) \
- CHOOSE_MODE_PROC(access_ok_tt, access_ok_skas, type, addr, size)
+ (__addr_range_nowrap(addr, size) && \
+ (__under_task_size(addr, size) || \
+ __access_ok_vsyscall(type, addr, size) || \
+ segment_eq(get_fs(), KERNEL_DS) || \
+ CHOOSE_MODE_PROC(access_ok_tt, access_ok_skas, type, addr, size)))
static inline int copy_from_user(void *to, const void __user *from, int n)
{
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