svn commit: r364166 - head/usr.sbin/crunch/crunchgen

[Alex Richardson]

Author: arichardson
Date: Wed Aug 12 15:49:06 2020
New Revision: 364166
URL: https://svnweb.freebsd.org/changeset/base/364166

Log:
  Fix crunchgen usage of mkstemp()
  
  On Glibc systems mkstemp can only be used once with the same template
  string since it will be modified in-place and no longer contain any 'X' chars.
  It is fine to reuse the same file here but we need to be explicit and use
  open() instead of mkstemp() on the second use.
  
  While touching this file also avoid a hardcoded /bin/pwd since that may not
  work when building on non-FreeBSD systems.
  
  Reviewed By:	brooks
  Differential Revision: https://reviews.freebsd.org/D25990

Modified:
  head/usr.sbin/crunch/crunchgen/crunchgen.c

Modified: head/usr.sbin/crunch/crunchgen/crunchgen.c
==============================================================================
--- head/usr.sbin/crunch/crunchgen/crunchgen.c	Wed Aug 12 14:45:31 2020	(r364165)
+++ head/usr.sbin/crunch/crunchgen/crunchgen.c	Wed Aug 12 15:49:06 2020	(r364166)
@@ -39,10 +39,13 @@ __FBSDID("$FreeBSD$");
 
 #include <ctype.h>
 #include <err.h>
+#include <fcntl.h>
 #include <paths.h>
+#include <stdbool.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
+#include <sysexits.h>
 #include <unistd.h>
 
 #define CRUNCH_VERSION	"0.2"
@@ -91,6 +94,7 @@ prog_t   *progs     = NULL;
 char confname[MAXPATHLEN], infilename[MAXPATHLEN];
 char outmkname[MAXPATHLEN], outcfname[MAXPATHLEN], execfname[MAXPATHLEN];
 char tempfname[MAXPATHLEN], cachename[MAXPATHLEN], curfilename[MAXPATHLEN];
+bool tempfname_initialized = false;
 char outhdrname[MAXPATHLEN] ;	/* user-supplied header for *.mk */
 char *objprefix;		/* where are the objects ? */
 char *path_make;
@@ -216,6 +220,7 @@ main(int argc, char **argv)
 	snprintf(cachename, sizeof(cachename), "%s.cache", confname);
 	snprintf(tempfname, sizeof(tempfname), "%s/crunchgen_%sXXXXXX",
 	getenv("TMPDIR") ? getenv("TMPDIR") : _PATH_TMP, confname);
+	tempfname_initialized = false;
 
 	parse_conf_file();
 	if (list_mode)
@@ -648,8 +653,7 @@ fillin_program(prog_t *p)
 
 	/* Determine the actual srcdir (maybe symlinked). */
 	if (p->srcdir) {
-		snprintf(line, MAXLINELEN, "cd %s && echo -n `/bin/pwd`",
-		    p->srcdir);
+		snprintf(line, MAXLINELEN, "cd %s && pwd", p->srcdir);
 		f = popen(line,"r");
 		if (!f)
 			errx(1, "Can't execute: %s\n", line);
@@ -721,14 +725,26 @@ fillin_program_objs(prog_t *p, char *path)
 
 	/* discover the objs from the srcdir Makefile */
 
-	if ((fd = mkstemp(tempfname)) == -1) {
-		perror(tempfname);
-		exit(1);
+	/*
+	 * We reuse the same temporary file name for multiple objects. However,
+	 * some libc implementations (such as glibc) return EINVAL if there
+	 * are no XXXXX characters in the template. This happens after the
+	 * first call to mkstemp since the argument is modified in-place.
+	 * To avoid this error we use open() instead of mkstemp() after the
+	 * call to mkstemp().
+	 */
+	if (tempfname_initialized) {
+		if ((fd = open(tempfname, O_CREAT | O_EXCL | O_RDWR, 0600)) == -1) {
+			err(EX_OSERR, "open(%s)", tempfname);
+		}
+	} else if ((fd = mkstemp(tempfname)) == -1) {
+		err(EX_OSERR, "mkstemp(%s)", tempfname);
 	}
+	tempfname_initialized = true;
 	if ((f = fdopen(fd, "w")) == NULL) {
-		warn("%s", tempfname);
+		warn("fdopen(%s)", tempfname);
 		goterror = 1;
-		return;
+		goto out;
 	}
 	if (p->objvar)
 		objvar = p->objvar;
@@ -763,14 +779,14 @@ fillin_program_objs(prog_t *p, char *path)
 	if ((f = popen(line, "r")) == NULL) {
 		warn("submake pipe");
 		goterror = 1;
-		return;
+		goto out;
 	}
 
 	while(fgets(line, MAXLINELEN, f)) {
 		if (strncmp(line, "OBJS= ", 6)) {
 			warnx("make error: %s", line);
 			goterror = 1;
-			continue;
+			goto out;
 		}
 
 		cp = line + 6;
@@ -793,7 +809,7 @@ fillin_program_objs(prog_t *p, char *path)
 		warnx("make error: make returned %d", rc);
 		goterror = 1;
 	}
-
+out:
 	unlink(tempfname);
 }