[Xen-changelog] [xen-unstable] Remove strcat/strncat/strcmp/strncmp. Replaced with safer

[Xen patchbot-unstable <patchbot-unstable@xxxxxxxxxxxxxxxxxxx>]

# HG changeset patch
# User kfraser@xxxxxxxxxxxxxxxxxxxxx
# Date 1170086683 0
# Node ID 647c06ba0b49ea05672ec8a4baa152445050d316
# Parent  d2784d93e760ad96ab25cb7cacee491177708ce0
Remove strcat/strncat/strcmp/strncmp. Replaced with safer
alternatives (including a new implementation of strlcat).
Signed-off-by: Keir Fraser <keir@xxxxxxxxxxxxx>
---
 xen/arch/x86/cpu/cyrix.c |    2 
 xen/arch/x86/setup.c     |   24 +++++-----
 xen/common/string.c      |  111 +++++++++++------------------------------------
 xen/include/xen/string.h |   26 +++++------
 4 files changed, 54 insertions(+), 109 deletions(-)

diff -r d2784d93e760 -r 647c06ba0b49 xen/arch/x86/cpu/cyrix.c
--- a/xen/arch/x86/cpu/cyrix.c  Mon Jan 29 15:01:33 2007 +0000
+++ b/xen/arch/x86/cpu/cyrix.c  Mon Jan 29 16:04:43 2007 +0000
@@ -302,7 +302,7 @@ static void __init init_cyrix(struct cpu
                break;
        }
        safe_strcpy(c->x86_model_id, Cx86_model[dir0_msn & 7]);
-       if (p) strcat(c->x86_model_id, p);
+       if (p) safe_strcat(c->x86_model_id, p);
        return;
 }
 
diff -r d2784d93e760 -r 647c06ba0b49 xen/arch/x86/setup.c
--- a/xen/arch/x86/setup.c      Mon Jan 29 15:01:33 2007 +0000
+++ b/xen/arch/x86/setup.c      Mon Jan 29 16:04:43 2007 +0000
@@ -751,19 +751,19 @@ void __init __start_xen(multiboot_info_t
             safe_strcpy(dom0_cmdline, cmdline);
         }
 
+        /* Append any extra parameters. */
+        if ( skip_ioapic_setup && !strstr(dom0_cmdline, "noapic") )
+            safe_strcat(dom0_cmdline, " noapic");
+        if ( acpi_skip_timer_override &&
+             !strstr(dom0_cmdline, "acpi_skip_timer_override") )
+            safe_strcat(dom0_cmdline, " acpi_skip_timer_override");
+        if ( (strlen(acpi_param) != 0) && !strstr(dom0_cmdline, "acpi=") )
+        {
+            safe_strcat(dom0_cmdline, " acpi=");
+            safe_strcat(dom0_cmdline, acpi_param);
+        }
+
         cmdline = dom0_cmdline;
-
-        /* Append any extra parameters. */
-        if ( skip_ioapic_setup && !strstr(cmdline, "noapic") )
-            strcat(cmdline, " noapic");
-        if ( acpi_skip_timer_override &&
-             !strstr(cmdline, "acpi_skip_timer_override") )
-            strcat(cmdline, " acpi_skip_timer_override");
-        if ( (strlen(acpi_param) != 0) && !strstr(cmdline, "acpi=") )
-        {
-            strcat(cmdline, " acpi=");
-            strcat(cmdline, acpi_param);
-        }
     }
 
     if ( (initrdidx > 0) && (initrdidx < mbi->mods_count) )
diff -r d2784d93e760 -r 647c06ba0b49 xen/common/string.c
--- a/xen/common/string.c       Mon Jan 29 15:01:33 2007 +0000
+++ b/xen/common/string.c       Mon Jan 29 16:04:43 2007 +0000
@@ -41,44 +41,6 @@ int strnicmp(const char *s1, const char 
 }
 #endif
 
-#ifndef __HAVE_ARCH_STRCPY
-/**
- * strcpy - Copy a %NUL terminated string
- * @dest: Where to copy the string to
- * @src: Where to copy the string from
- */
-char * strcpy(char * dest,const char *src)
-{
-       char *tmp = dest;
-
-       while ((*dest++ = *src++) != '\0')
-               /* nothing */;
-       return tmp;
-}
-#endif
-
-#ifndef __HAVE_ARCH_STRNCPY
-/**
- * strncpy - Copy a length-limited, %NUL-terminated string
- * @dest: Where to copy the string to
- * @src: Where to copy the string from
- * @count: The maximum number of bytes to copy
- *
- * Note that unlike userspace strncpy, this does not %NUL-pad the buffer.
- * However, the result is not %NUL-terminated if the source exceeds
- * @count bytes.
- */
-char * strncpy(char * dest,const char *src,size_t count)
-{
-       char *tmp = dest;
-
-       while (count-- && (*dest++ = *src++) != '\0')
-               /* nothing */;
-
-       return tmp;
-}
-#endif
-
 #ifndef __HAVE_ARCH_STRLCPY
 /**
  * strlcpy - Copy a %NUL terminated string into a sized buffer
@@ -105,52 +67,33 @@ EXPORT_SYMBOL(strlcpy);
 EXPORT_SYMBOL(strlcpy);
 #endif
 
-#ifndef __HAVE_ARCH_STRCAT
-/**
- * strcat - Append one %NUL-terminated string to another
- * @dest: The string to be appended to
- * @src: The string to append to it
- */
-char * strcat(char * dest, const char * src)
-{
-       char *tmp = dest;
-
-       while (*dest)
-               dest++;
-       while ((*dest++ = *src++) != '\0')
-               ;
-
-       return tmp;
-}
-#endif
-
-#ifndef __HAVE_ARCH_STRNCAT
-/**
- * strncat - Append a length-limited, %NUL-terminated string to another
- * @dest: The string to be appended to
- * @src: The string to append to it
- * @count: The maximum numbers of bytes to copy
- *
- * Note that in contrast to strncpy, strncat ensures the result is
- * terminated.
- */
-char * strncat(char *dest, const char *src, size_t count)
-{
-       char *tmp = dest;
-
-       if (count) {
-               while (*dest)
-                       dest++;
-               while ((*dest++ = *src++)) {
-                       if (--count == 0) {
-                               *dest = '\0';
-                               break;
-                       }
-               }
-       }
-
-       return tmp;
-}
+#ifndef __HAVE_ARCH_STRLCAT
+/**
+ * strlcat - Append a %NUL terminated string into a sized buffer
+ * @dest: Where to copy the string to
+ * @src: Where to copy the string from
+ * @size: size of destination buffer
+ *
+ * Compatible with *BSD: the result is always a valid
+ * NUL-terminated string that fits in the buffer (unless,
+ * of course, the buffer size is zero).
+ */
+size_t strlcat(char *dest, const char *src, size_t size)
+{
+       size_t slen = strlen(src);
+       size_t dlen = strnlen(dest, size);
+       char *p = dest + dlen;
+
+       while ((p - dest) < size)
+               if ((*p++ = *src++) == '\0')
+                       break;
+
+       if (dlen < size)
+               *(p-1) = '\0';
+
+       return slen + dlen;
+}
+EXPORT_SYMBOL(strlcat);
 #endif
 
 #ifndef __HAVE_ARCH_STRCMP
diff -r d2784d93e760 -r 647c06ba0b49 xen/include/xen/string.h
--- a/xen/include/xen/string.h  Mon Jan 29 15:01:33 2007 +0000
+++ b/xen/include/xen/string.h  Mon Jan 29 16:04:43 2007 +0000
@@ -19,20 +19,20 @@ extern __kernel_size_t strspn(const char
  */
 #include <asm/string.h>
 
-#ifndef __HAVE_ARCH_STRCPY
-extern char * strcpy(char *,const char *);
-#endif
-#ifndef __HAVE_ARCH_STRNCPY
-extern char * strncpy(char *,const char *, __kernel_size_t);
-#endif
+/*
+ * These string functions are considered too dangerous for normal use.
+ * Use safe_strcpy(), safe_strcat(), strlcpy(), strlcat() as appropriate.
+ */
+#define strcpy  __xen_has_no_strcpy__
+#define strcat  __xen_has_no_strcat__
+#define strncpy __xen_has_no_strncpy__
+#define strncat __xen_has_no_strncat__
+
 #ifndef __HAVE_ARCH_STRLCPY
 extern size_t strlcpy(char *,const char *, __kernel_size_t);
 #endif
-#ifndef __HAVE_ARCH_STRCAT
-extern char * strcat(char *, const char *);
-#endif
-#ifndef __HAVE_ARCH_STRNCAT
-extern char * strncat(char *, const char *, __kernel_size_t);
+#ifndef __HAVE_ARCH_STRLCAT
+extern size_t strlcat(char *,const char *, __kernel_size_t);
 #endif
 #ifndef __HAVE_ARCH_STRCMP
 extern int strcmp(const char *,const char *);
@@ -82,6 +82,8 @@ extern void * memchr(const void *,int,__
 }
 #endif
 
-#define safe_strcpy(d, s) strlcpy(d, s, sizeof(d))
+/* safe_xxx always NUL-terminates and returns !=0 if result is truncated. */
+#define safe_strcpy(d, s) (strlcpy(d, s, sizeof(d)) >= sizeof(d))
+#define safe_strcat(d, s) (strlcat(d, s, sizeof(d)) >= sizeof(d))
 
 #endif /* _LINUX_STRING_H_ */

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