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authorAlexander Potapenko <glider@google.com>2022-10-25 00:21:44 +0300
committerAndrew Morton <akpm@linux-foundation.org>2022-10-28 23:37:23 +0300
commit78a498c3a227f2ac773a8234b2ce092a4403f2c3 (patch)
treed7efd152160584209dfcbde2aa4cfaa65f728425 /include
parent59c8a02e24894e75639bcecc3cb1e768a2792220 (diff)
downloadlinux-78a498c3a227f2ac773a8234b2ce092a4403f2c3.tar.xz
x86: fortify: kmsan: fix KMSAN fortify builds
Ensure that KMSAN builds replace memset/memcpy/memmove calls with the respective __msan_XXX functions, and that none of the macros are redefined twice. This should allow building kernel with both CONFIG_KMSAN and CONFIG_FORTIFY_SOURCE. Link: https://lkml.kernel.org/r/20221024212144.2852069-5-glider@google.com Link: https://github.com/google/kmsan/issues/89 Signed-off-by: Alexander Potapenko <glider@google.com> Reported-by: Tamas K Lengyel <tamas.lengyel@zentific.com> Cc: Nathan Chancellor <nathan@kernel.org> Cc: Nick Desaulniers <ndesaulniers@google.com> Cc: Kees Cook <keescook@chromium.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'include')
-rw-r--r--include/linux/fortify-string.h17
-rw-r--r--include/linux/kmsan_string.h21
2 files changed, 36 insertions, 2 deletions
diff --git a/include/linux/fortify-string.h b/include/linux/fortify-string.h
index 4029fe368a4f..18a31b125f9d 100644
--- a/include/linux/fortify-string.h
+++ b/include/linux/fortify-string.h
@@ -43,11 +43,24 @@ extern __kernel_size_t __underlying_strlen(const char *p) __RENAME(strlen);
extern char *__underlying_strncat(char *p, const char *q, __kernel_size_t count) __RENAME(strncat);
extern char *__underlying_strncpy(char *p, const char *q, __kernel_size_t size) __RENAME(strncpy);
#else
-#define __underlying_memchr __builtin_memchr
-#define __underlying_memcmp __builtin_memcmp
+
+#if defined(__SANITIZE_MEMORY__)
+/*
+ * For KMSAN builds all memcpy/memset/memmove calls should be replaced by the
+ * corresponding __msan_XXX functions.
+ */
+#include <linux/kmsan_string.h>
+#define __underlying_memcpy __msan_memcpy
+#define __underlying_memmove __msan_memmove
+#define __underlying_memset __msan_memset
+#else
#define __underlying_memcpy __builtin_memcpy
#define __underlying_memmove __builtin_memmove
#define __underlying_memset __builtin_memset
+#endif
+
+#define __underlying_memchr __builtin_memchr
+#define __underlying_memcmp __builtin_memcmp
#define __underlying_strcat __builtin_strcat
#define __underlying_strcpy __builtin_strcpy
#define __underlying_strlen __builtin_strlen
diff --git a/include/linux/kmsan_string.h b/include/linux/kmsan_string.h
new file mode 100644
index 000000000000..7287da6f52ef
--- /dev/null
+++ b/include/linux/kmsan_string.h
@@ -0,0 +1,21 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * KMSAN string functions API used in other headers.
+ *
+ * Copyright (C) 2022 Google LLC
+ * Author: Alexander Potapenko <glider@google.com>
+ *
+ */
+#ifndef _LINUX_KMSAN_STRING_H
+#define _LINUX_KMSAN_STRING_H
+
+/*
+ * KMSAN overrides the default memcpy/memset/memmove implementations in the
+ * kernel, which requires having __msan_XXX function prototypes in several other
+ * headers. Keep them in one place instead of open-coding.
+ */
+void *__msan_memcpy(void *dst, const void *src, size_t size);
+void *__msan_memset(void *s, int c, size_t n);
+void *__msan_memmove(void *dest, const void *src, size_t len);
+
+#endif /* _LINUX_KMSAN_STRING_H */