@@ -315,6 +315,10 @@ config GENERIC_ISA_DMA
def_bool y
depends on ISA_DMA_API
+config GENERIC_CSUM
+ bool
+ default y if KMSAN || KASAN
+
config GENERIC_BUG
def_bool y
depends on BUG
@@ -1,9 +1,13 @@
/* SPDX-License-Identifier: GPL-2.0 */
-#define _HAVE_ARCH_COPY_AND_CSUM_FROM_USER 1
-#define HAVE_CSUM_COPY_USER
-#define _HAVE_ARCH_CSUM_AND_COPY
-#ifdef CONFIG_X86_32
-# include <asm/checksum_32.h>
+#ifdef CONFIG_GENERIC_CSUM
+# include <asm-generic/checksum.h>
#else
-# include <asm/checksum_64.h>
+# define _HAVE_ARCH_COPY_AND_CSUM_FROM_USER 1
+# define HAVE_CSUM_COPY_USER
+# define _HAVE_ARCH_CSUM_AND_COPY
+# ifdef CONFIG_X86_32
+# include <asm/checksum_32.h>
+# else
+# include <asm/checksum_64.h>
+# endif
#endif
@@ -65,7 +65,9 @@ ifneq ($(CONFIG_X86_CMPXCHG64),y)
endif
else
obj-y += iomap_copy_64.o
+ifneq ($(CONFIG_GENERIC_CSUM),y)
lib-y += csum-partial_64.o csum-copy_64.o csum-wrappers_64.o
+endif
lib-y += clear_page_64.o copy_page_64.o
lib-y += memmove_64.o memset_64.o
lib-y += copy_user_64.o
This is needed to allow memory tools like KASAN and KMSAN see the memory accesses from the checksum code. Without CONFIG_GENERIC_CSUM the tools can't see memory accesses originating from handwritten assembly code. For KASAN it's a question of detecting more bugs, for KMSAN using the C implementation also helps avoid false positives originating from seemingly uninitialized checksum values. Signed-off-by: Alexander Potapenko <glider@google.com> --- Link: https://linux-review.googlesource.com/id/I3e95247be55b1112af59dbba07e8cbf34e50a581 --- arch/x86/Kconfig | 4 ++++ arch/x86/include/asm/checksum.h | 16 ++++++++++------ arch/x86/lib/Makefile | 2 ++ 3 files changed, 16 insertions(+), 6 deletions(-)