x86: Add a Kconfig option to turn the copy_from_user warnings into errors
For automated testing it is useful to have the option to turn
the warnings on copy_from_user() etc checks into errors:
In function ‘copy_from_user’,
inlined from ‘fd_copyin’ at drivers/block/floppy.c:3080,
inlined from ‘fd_ioctl’ at drivers/block/floppy.c:3503:
linux/arch/x86/include/asm/uaccess_32.h:213:
error: call to ‘copy_from_user_overflow’ declared with attribute error:
copy_from_user buffer size is not provably correct
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
LKML-Reference: <20091002075050.4e9f7641@infradead.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/arch/x86/include/asm/uaccess_32.h b/arch/x86/include/asm/uaccess_32.h
index 952f9e7..0c9825e 100644
--- a/arch/x86/include/asm/uaccess_32.h
+++ b/arch/x86/include/asm/uaccess_32.h
@@ -193,7 +193,9 @@
extern void copy_from_user_overflow(void)
-#ifdef CONFIG_DEBUG_STACKOVERFLOW
+#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
;