CVS commit: src/sys

[Maxime Villard]

Module Name:    src
Committed By:   maxv
Date:           Fri Apr  3 18:44:50 UTC 2020

Modified Files:
        src/sys/kern: subr_asan.c
        src/sys/lib/libkern: libkern.h

Log Message:
Add KASAN instrumentation on strcat/strchr/strrchr.


To generate a diff of this commit:
cvs rdiff -u -r1.19 -r1.20 src/sys/kern/subr_asan.c
cvs rdiff -u -r1.137 -r1.138 src/sys/lib/libkern/libkern.h

Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.


Modified files:

Index: src/sys/kern/subr_asan.c
diff -u src/sys/kern/subr_asan.c:1.19 src/sys/kern/subr_asan.c:1.20
--- src/sys/kern/subr_asan.c:1.19	Fri Apr  3 18:12:39 2020
+++ src/sys/kern/subr_asan.c	Fri Apr  3 18:44:50 2020
@@ -1,4 +1,4 @@
-/*	$NetBSD: subr_asan.c,v 1.19 2020/04/03 18:12:39 maxv Exp $	*/
+/*	$NetBSD: subr_asan.c,v 1.20 2020/04/03 18:44:50 maxv Exp $	*/
 
 /*
  * Copyright (c) 2018-2020 The NetBSD Foundation, Inc.
@@ -30,7 +30,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: subr_asan.c,v 1.19 2020/04/03 18:12:39 maxv Exp $");
+__KERNEL_RCSID(0, "$NetBSD: subr_asan.c,v 1.20 2020/04/03 18:44:50 maxv Exp $");
 
 #include <sys/param.h>
 #include <sys/device.h>
@@ -507,6 +507,37 @@ kasan_strlen(const char *str)
 	return (s - str);
 }
 
+char *
+kasan_strcat(char *dst, const char *src)
+{
+	size_t ldst, lsrc;
+
+	ldst = __builtin_strlen(dst);
+	lsrc = __builtin_strlen(src);
+	kasan_shadow_check((unsigned long)dst, ldst + lsrc + 1, true,
+	    __RET_ADDR);
+	kasan_shadow_check((unsigned long)src, lsrc + 1, false,
+	    __RET_ADDR);
+
+	return __builtin_strcat(dst, src);
+}
+
+char *
+kasan_strchr(const char *s, int c)
+{
+	kasan_shadow_check((unsigned long)s, __builtin_strlen(s) + 1, false,
+	    __RET_ADDR);
+	return __builtin_strchr(s, c);
+}
+
+char *
+kasan_strrchr(const char *s, int c)
+{
+	kasan_shadow_check((unsigned long)s, __builtin_strlen(s) + 1, false,
+	    __RET_ADDR);
+	return __builtin_strrchr(s, c);
+}
+
 #undef kcopy
 #undef copystr
 #undef copyinstr

Index: src/sys/lib/libkern/libkern.h
diff -u src/sys/lib/libkern/libkern.h:1.137 src/sys/lib/libkern/libkern.h:1.138
--- src/sys/lib/libkern/libkern.h:1.137	Sat Dec 14 17:23:47 2019
+++ src/sys/lib/libkern/libkern.h	Fri Apr  3 18:44:50 2020
@@ -1,4 +1,4 @@
-/*	$NetBSD: libkern.h,v 1.137 2019/12/14 17:23:47 riastradh Exp $	*/
+/*	$NetBSD: libkern.h,v 1.138 2020/04/03 18:44:50 maxv Exp $	*/
 
 /*-
  * Copyright (c) 1992, 1993
@@ -430,7 +430,14 @@ size_t	 kmsan_strlen(const char *);
 #endif
 
 /* These exist in GCC 3.x, but we don't bother. */
-#if defined(_KERNEL) && defined(KMSAN)
+#if defined(_KERNEL) && defined(KASAN)
+char	*kasan_strcat(char *, const char *);
+char	*kasan_strchr(const char *, int);
+char	*kasan_strrchr(const char *, int);
+#define	strcat(d, s)		kasan_strcat(d, s)
+#define	strchr(s, c)		kasan_strchr(s, c)
+#define	strrchr(s, c)		kasan_strrchr(s, c)
+#elif defined(_KERNEL) && defined(KMSAN)
 char	*kmsan_strcat(char *, const char *);
 char	*kmsan_strchr(const char *, int);
 char	*kmsan_strrchr(const char *, int);