parisc: add strict copy size checks (v2)
Add CONFIG_DEBUG_STRICT_USER_COPY_CHECKS, copied from the x86
implementation. Tested with 32 and 64bit kernel.
Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: Kyle McMartin <kyle@mcmartin.ca>
diff --git a/arch/parisc/include/asm/uaccess.h b/arch/parisc/include/asm/uaccess.h
index 7cf799d..ff4cf9d 100644
--- a/arch/parisc/include/asm/uaccess.h
+++ b/arch/parisc/include/asm/uaccess.h
@@ -7,6 +7,7 @@
#include <asm/page.h>
#include <asm/system.h>
#include <asm/cache.h>
+#include <asm/errno.h>
#include <asm-generic/uaccess-unaligned.h>
#define VERIFY_READ 0
@@ -234,13 +235,35 @@
unsigned long copy_to_user(void __user *dst, const void *src, unsigned long len);
#define __copy_to_user copy_to_user
-unsigned long copy_from_user(void *dst, const void __user *src, unsigned long len);
-#define __copy_from_user copy_from_user
+unsigned long __copy_from_user(void *dst, const void __user *src, unsigned long len);
unsigned long copy_in_user(void __user *dst, const void __user *src, unsigned long len);
#define __copy_in_user copy_in_user
#define __copy_to_user_inatomic __copy_to_user
#define __copy_from_user_inatomic __copy_from_user
+extern void copy_from_user_overflow(void)
+#ifdef CONFIG_DEBUG_STRICT_USER_COPY_CHECKS
+ __compiletime_error("copy_from_user() buffer size is not provably correct")
+#else
+ __compiletime_warning("copy_from_user() buffer size is not provably correct")
+#endif
+;
+
+static inline unsigned long __must_check copy_from_user(void *to,
+ const void __user *from,
+ unsigned long n)
+{
+ int sz = __compiletime_object_size(to);
+ int ret = -EFAULT;
+
+ if (likely(sz == -1 || !__builtin_constant_p(n) || sz >= n))
+ ret = __copy_from_user(to, from, n);
+ else
+ copy_from_user_overflow();
+
+ return ret;
+}
+
struct pt_regs;
int fixup_exception(struct pt_regs *regs);