[PATCH 30/64] fortify: Move remaining fortify helpers into fortify-string.h

Kees Cook
2021-07-27T20:59:54Z

When commit a28a6e860c6c ("string.h: move fortified functions definitions
in a dedicated header.") moved the fortify-specific code, some helpers
were left behind. Moves the remaining fortify-specific helpers into
fortify-string.h so they're together where they're used. This requires
that any FORTIFY helper function prototypes be conditionally built to
avoid "no prototype" warnings. Additionally removes unused helpers.

Signed-off-by: Kees Cook <keescook@chromium.org>
---
include/linux/fortify-string.h | 7 +++++++
include/linux/string.h | 9 ---------
lib/string_helpers.c | 2 ++
3 files changed, 9 insertions(+), 9 deletions(-)

diff --git a/include/linux/fortify-string.h b/include/linux/fortify-string.h
index c1be37437e77..7e67d02764db 100644
--- a/include/linux/fortify-string.h
+++ b/include/linux/fortify-string.h
@@ -2,6 +2,13 @@
#ifndef _LINUX_FORTIFY_STRING_H_
#define _LINUX_FORTIFY_STRING_H_

+#define __FORTIFY_INLINE extern __always_inline __attribute__((gnu_inline))
+#define __RENAME(x) __asm__(#x)
+
+void fortify_panic(const char *name) __noreturn __cold;
+void __read_overflow(void) __compiletime_error("detected read beyond size of object (1st parameter)");
+void __read_overflow2(void) __compiletime_error("detected read beyond size of object (2nd parameter)");
+void __write_overflow(void) __compiletime_error("detected write beyond size of object (1st parameter)");

#if defined(CONFIG_KASAN_GENERIC) || defined(CONFIG_KASAN_SW_TAGS)
extern void *__underlying_memchr(const void *p, int c, __kernel_size_t size) __RENAME(memchr);
diff --git a/include/linux/string.h b/include/linux/string.h
index b48d2d28e0b1..9473f81b9db2 100644
--- a/include/linux/string.h
+++ b/include/linux/string.h
@@ -249,15 +249,6 @@ static inline const char *kbasename(const char *path)
return tail ? tail + 1 : path;
}

-#define __FORTIFY_INLINE extern __always_inline __attribute__((gnu_inline))
-#define __RENAME(x) __asm__(#x)
-
-void fortify_panic(const char *name) __noreturn __cold;
-void __read_overflow(void) __compiletime_error("detected read beyond size of object passed as 1st parameter");
-void __read_overflow2(void) __compiletime_error("detected read beyond size of object passed as 2nd parameter");
-void __read_overflow3(void) __compiletime_error("detected read beyond size of object passed as 3rd parameter");
-void __write_overflow(void) __compiletime_error("detected write beyond size of object passed as 1st parameter");
-
#if !defined(__NO_FORTIFY) && defined(__OPTIMIZE__) && defined(CONFIG_FORTIFY_SOURCE)
#include <linux/fortify-string.h>
#endif
diff --git a/lib/string_helpers.c b/lib/string_helpers.c
index bde13612c25d..faa9d8e4e2c5 100644
--- a/lib/string_helpers.c
+++ b/lib/string_helpers.c
@@ -883,9 +883,11 @@ char *strreplace(char *s, char old, char new)
}
EXPORT_SYMBOL(strreplace);

+#ifdef CONFIG_FORTIFY_SOURCE
void fortify_panic(const char *name)
{
pr_emerg("detected buffer overflow in %s\n", name);
BUG();
}
EXPORT_SYMBOL(fortify_panic);
+#endif /* CONFIG_FORTIFY_SOURCE */
--
2.30.2