[src/trunk]: src/sys Ah, strcat/strchr/strrchr are ASM functions, so instrume...

[maxv <maxv%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/b4976c08a4ed
branches:  trunk
changeset: 465435:b4976c08a4ed
user:      maxv <maxv%NetBSD.org@localhost>
date:      Fri Nov 22 14:28:46 2019 +0000

description:
Ah, strcat/strchr/strrchr are ASM functions, so instrument them.

diffstat:

 sys/kern/subr_msan.c      |  53 +++++++++++++++++++++++++++++++++++++++++++---
 sys/lib/libkern/libkern.h |  15 ++++++++++--
 2 files changed, 61 insertions(+), 7 deletions(-)

diffs (122 lines):

diff -r bab40d6213c5 -r b4976c08a4ed sys/kern/subr_msan.c
--- a/sys/kern/subr_msan.c      Fri Nov 22 13:30:19 2019 +0000
+++ b/sys/kern/subr_msan.c      Fri Nov 22 14:28:46 2019 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: subr_msan.c,v 1.2 2019/11/15 12:18:46 maxv Exp $       */
+/*     $NetBSD: subr_msan.c,v 1.3 2019/11/22 14:28:46 maxv Exp $       */
 
 /*
  * Copyright (c) 2019 The NetBSD Foundation, Inc.
@@ -32,7 +32,7 @@
 #define KMSAN_NO_INST
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: subr_msan.c,v 1.2 2019/11/15 12:18:46 maxv Exp $");
+__KERNEL_RCSID(0, "$NetBSD: subr_msan.c,v 1.3 2019/11/22 14:28:46 maxv Exp $");
 
 #include <sys/param.h>
 #include <sys/device.h>
@@ -187,7 +187,7 @@
                var = (char *)ptr + 4;
                strlcpy(buf, var, sizeof(buf));
                var = buf;
-               fn = strchr(buf, '@');
+               fn = __builtin_strchr(buf, '@');
                *fn++ = '\0';
                REPORT("MSan: Uninitialized %s Memory In %s() At Offset "
                    "%zu, Variable '%s' From %s()\n", typename, hook, off,
@@ -238,7 +238,7 @@
                var = (char *)ptr + 4;
                strlcpy(buf, var, sizeof(buf));
                var = buf;
-               fn = strchr(buf, '@');
+               fn = __builtin_strchr(buf, '@');
                *fn++ = '\0';
                REPORT("MSan: Uninitialized Variable '%s' From %s()\n",
                    var, fn);
@@ -754,6 +754,51 @@
        return (s - str);
 }
 
+char *
+kmsan_strcat(char *dst, const char *src)
+{
+       size_t ldst, lsrc;
+       char *ret;
+
+       kmsan_check_arg(sizeof(dst) + sizeof(src), "strcat");
+
+       ldst = __builtin_strlen(dst);
+       lsrc = __builtin_strlen(src);
+       kmsan_shadow_check(dst, ldst + 1, "strcat");
+       kmsan_shadow_check(src, lsrc + 1, "strcat");
+       ret = __builtin_strcat(dst, src);
+       kmsan_shadow_fill(dst, KMSAN_STATE_INITED, ldst + lsrc + 1);
+
+       kmsan_init_ret(sizeof(char *));
+       return ret;
+}
+
+char *
+kmsan_strchr(const char *s, int c)
+{
+       char *ret;
+
+       kmsan_check_arg(sizeof(s) + sizeof(c), "strchr");
+       kmsan_shadow_check(s, __builtin_strlen(s), "strchr");
+       ret = __builtin_strchr(s, c);
+
+       kmsan_init_ret(sizeof(char *));
+       return ret;
+}
+
+char *
+kmsan_strrchr(const char *s, int c)
+{
+       char *ret;
+
+       kmsan_check_arg(sizeof(s) + sizeof(c), "strrchr");
+       kmsan_shadow_check(s, __builtin_strlen(s), "strrchr");
+       ret = __builtin_strrchr(s, c);
+
+       kmsan_init_ret(sizeof(char *));
+       return ret;
+}
+
 #undef kcopy
 #undef copystr
 #undef copyin
diff -r bab40d6213c5 -r b4976c08a4ed sys/lib/libkern/libkern.h
--- a/sys/lib/libkern/libkern.h Fri Nov 22 13:30:19 2019 +0000
+++ b/sys/lib/libkern/libkern.h Fri Nov 22 14:28:46 2019 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: libkern.h,v 1.134 2019/11/14 16:23:53 maxv Exp $       */
+/*     $NetBSD: libkern.h,v 1.135 2019/11/22 14:28:46 maxv Exp $       */
 
 /*-
  * Copyright (c) 1992, 1993
@@ -438,13 +438,22 @@
 #endif
 
 /* These exist in GCC 3.x, but we don't bother. */
+#if defined(_KERNEL) && defined(KMSAN)
+char   *kmsan_strcat(char *, const char *);
+char   *kmsan_strchr(const char *, int);
+char   *kmsan_strrchr(const char *, int);
+#define        strcat(d, s)            kmsan_strcat(d, s)
+#define        strchr(s, c)            kmsan_strchr(s, c)
+#define        strrchr(s, c)           kmsan_strrchr(s, c)
+#else
 char   *strcat(char *, const char *);
+char   *strchr(const char *, int);
+char   *strrchr(const char *, int);
+#endif
 size_t  strcspn(const char *, const char *);
 char   *strncpy(char *, const char *, size_t);
 char   *strncat(char *, const char *, size_t);
 int     strncmp(const char *, const char *, size_t);
-char   *strchr(const char *, int);
-char   *strrchr(const char *, int);
 char   *strstr(const char *, const char *);
 char   *strpbrk(const char *, const char *);
 size_t  strspn(const char *, const char *);