svn commit: r207593 - stable/8/usr.sbin/config

[Warner Losh]

Author: imp
Date: Tue May  4 03:56:25 2010
New Revision: 207593
URL: http://svn.freebsd.org/changeset/base/207593

Log:
  MFC: r207461
  
    sparc64, and possibly other architectures, pads the length of the
    section holding the config file to sh_addralign bytes using NULs.
    This bogusly triggers an assert.  Break out of the loop when we hit an
    NUL within that many bytes of the end.

Modified:
  stable/8/usr.sbin/config/main.c
Directory Properties:
  stable/8/usr.sbin/config/   (props changed)

Modified: stable/8/usr.sbin/config/main.c
==============================================================================
--- stable/8/usr.sbin/config/main.c	Tue May  4 01:46:58 2010	(r207592)
+++ stable/8/usr.sbin/config/main.c	Tue May  4 03:56:25 2010	(r207593)
@@ -670,7 +670,7 @@ kernconfdump(const char *file)
 	struct stat st;
 	FILE *fp, *pp;
 	int error, len, osz, r;
-	unsigned int i, off, size;
+	unsigned int i, off, size, t1, t2, align;
 	char *cmd, *o;
 
 	r = open(file, O_RDONLY);
@@ -689,8 +689,8 @@ kernconfdump(const char *file)
 	if (o == NULL)
 		err(EXIT_FAILURE, "Couldn't allocate memory");
 	/* ELF note section header. */
-	asprintf(&cmd, "/usr/bin/elfdump -c %s | grep -A 5 kern_conf"
-	    "| tail -2 | cut -d ' ' -f 2 | paste - - -", file);
+	asprintf(&cmd, "/usr/bin/elfdump -c %s | grep -A 8 kern_conf"
+	    "| tail -5 | cut -d ' ' -f 2 | paste - - - - -", file);
 	if (cmd == NULL)
 		errx(EXIT_FAILURE, "asprintf() failed");
 	pp = popen(cmd, "r");
@@ -699,24 +699,28 @@ kernconfdump(const char *file)
 	free(cmd);
 	len = fread(o, osz, 1, pp);
 	pclose(pp);
-	r = sscanf(o, "%d\t%d", &off, &size);
+	r = sscanf(o, "%d%d%d%d%d", &off, &size, &t1, &t2, &align);
 	free(o);
-	if (r != 2)
+	if (r != 5)
 		errx(EXIT_FAILURE, "File %s doesn't contain configuration "
 		    "file. Either unsupported, or not compiled with "
 		    "INCLUDE_CONFIG_FILE", file);
 	r = fseek(fp, off, SEEK_CUR);
 	if (r != 0)
 		err(EXIT_FAILURE, "fseek() failed");
-	for (i = 0; i < size - 1; i++) {
+	for (i = 0; i < size; i++) {
 		r = fgetc(fp);
 		if (r == EOF)
 			break;
 		/* 
 		 * If '\0' is present in the middle of the configuration
 		 * string, this means something very weird is happening.
-		 * Make such case very visible.
+		 * Make such case very visible.  However, some architectures
+		 * pad the length of the section with NULs to a multiple of
+		 * sh_addralign, allow a NUL in that part of the section.
 		 */
+		if (r == '\0' && (size - i) < align)
+			break;
 		assert(r != '\0' && ("Char present in the configuration "
 		    "string mustn't be equal to 0"));
 		fputc(r, stdout);