Re: [PATCH] avoid assuming MAXPATHLEN in config(8)
2011/7/7 Ed Schouten <ed@80386.nl>:
> Considering that the function is rather small anyway, why not compile it
> in unconditionally (though having a different name).
Hi Ed,
I made the adjustment you requested, plus a bit more polishing
(plugged a memleak, etc), and then I hit what seems like a memory
corruption heisenbug.
I haven't been able to determine whether my patch introduces this bug
or it just uncovers it. As for now please disregard my request untill
I have time to debug this properly.
Thanks
--
Robert Millan
=== modified file 'config.h'
--- config.h 2011-07-07 13:59:05 +0000
+++ config.h 2011-07-07 14:06:28 +0000
@@ -199,7 +199,7 @@
extern int maxusers;
extern char *PREFIX; /* Config file name - for error messages */
-extern char srcdir[]; /* root of the kernel source tree */
+extern char *srcdir; /* root of the kernel source tree */
#define eq(a,b) (!strcmp(a,b))
#define ns(s) strdup(s)
=== modified file 'main.c'
--- main.c 2011-07-07 13:59:05 +0000
+++ main.c 2011-07-07 17:51:39 +0000
@@ -71,8 +71,8 @@
#define CDIR "../compile/"
char * PREFIX;
-char destdir[MAXPATHLEN];
-char srcdir[MAXPATHLEN];
+char * destdir;
+char * srcdir;
int debugging;
int profiling;
@@ -122,8 +122,8 @@
printmachine = 1;
break;
case 'd':
- if (*destdir == '\0')
- strlcpy(destdir, optarg, sizeof(destdir));
+ if (destdir == NULL)
+ destdir = strdup(optarg);
else
errx(EXIT_FAILURE, "directory already set");
break;
@@ -165,14 +165,13 @@
err(2, "%s", PREFIX);
yyfile = PREFIX;
}
- if (*destdir != '\0') {
+ if (destdir != NULL) {
len = strlen(destdir);
while (len > 1 && destdir[len - 1] == '/')
destdir[--len] = '\0';
get_srcdir();
} else {
- strlcpy(destdir, CDIR, sizeof(destdir));
- strlcat(destdir, PREFIX, sizeof(destdir));
+ (void) asprintf(&destdir, "%s%s", CDIR, PREFIX);
}
SLIST_INIT(&cputype);
@@ -230,6 +229,27 @@
}
/*
+ * xrealpath
+ * realpath() with extension to use malloc() when resolved is NULL.
+ */
+static char *
+xrealpath(const char *name, char *resolved)
+{
+#ifdef MAXPATHLEN
+ if (resolved == NULL) {
+ resolved = malloc(MAXPATHLEN);
+ if (realpath(name, resolved) == NULL) {
+ free(resolved);
+ resolved = NULL;
+ }
+ } else
+#endif
+ resolved = realpath(name, resolved);
+
+ return resolved;
+}
+
+/*
* get_srcdir
* determine the root of the kernel source tree
* and save that in srcdir.
@@ -241,7 +261,9 @@
char *p, *pwd;
int i;
- if (realpath("../..", srcdir) == NULL)
+ if (srcdir != NULL)
+ free(srcdir);
+ if ((srcdir = xrealpath("../..", NULL)) == NULL)
err(EXIT_FAILURE, "Unable to find root of source tree");
if ((pwd = getenv("PWD")) != NULL && *pwd == '/' &&
(pwd = strdup(pwd)) != NULL) {
@@ -254,9 +276,12 @@
*p = '\0';
}
if (stat(pwd, &lg) != -1 && stat(srcdir, &phy) != -1 &&
- lg.st_dev == phy.st_dev && lg.st_ino == phy.st_ino)
- strlcpy(srcdir, pwd, MAXPATHLEN);
- free(pwd);
+ lg.st_dev == phy.st_dev && lg.st_ino == phy.st_ino) {
+ free(srcdir);
+ srcdir = pwd;
+ } else {
+ free(pwd);
+ }
}
}
@@ -386,9 +411,9 @@
char *cp = NULL;
if (file)
- asprintf(&cp, "%s/%s", destdir, file);
+ asprintf(&cp, "%s/%s", destdir ? destdir : "", file);
else
- cp = strdup(destdir);
+ cp = strdup(destdir ? destdir : "");
return (cp);
}
=== modified file 'mkmakefile.c'
--- mkmakefile.c 2011-07-07 13:59:05 +0000
+++ mkmakefile.c 2011-07-07 14:12:06 +0000
@@ -152,7 +152,7 @@
fprintf(ofp, "DEBUG=-g\n");
if (profiling)
fprintf(ofp, "PROFLEVEL=%d\n", profiling);
- if (*srcdir != '\0')
+ if (srcdir != NULL)
fprintf(ofp,"S=%s\n", srcdir);
while (fgets(line, BUFSIZ, ifp) != 0) {
if (*line != '%') {
@@ -304,9 +304,9 @@
}
static void
-read_file(char *fname)
+read_file(const char *fname)
{
- char ifname[MAXPATHLEN];
+ char *ifname;
FILE *fp;
struct file_list *tp;
struct device *dp;
@@ -349,8 +349,9 @@
fname);
exit(1);
}
- (void) snprintf(ifname, sizeof(ifname), "../../%s", wd);
+ (void) asprintf(&ifname, "../../%s", wd);
read_file(ifname);
+ free(ifname);
while (((wd = get_word(fp)) != (char *)EOF) && wd)
;
goto next;
@@ -559,14 +560,13 @@
static void
read_files(void)
{
- char fname[MAXPATHLEN];
+ char *fname;
struct files_name *nl, *tnl;
- (void) snprintf(fname, sizeof(fname), "../../conf/files");
- read_file(fname);
- (void) snprintf(fname, sizeof(fname),
- "../../conf/files.%s", machinename);
- read_file(fname);
+ read_file("../../conf/files");
+ (void) asprintf(&fname, "../../conf/files.%s", machinename);
+ read_file(fname);
+ free(fname);
for (nl = STAILQ_FIRST(&fntab); nl != NULL; nl = tnl) {
read_file(nl->f_name);
tnl = STAILQ_NEXT(nl, f_next);
=== modified file 'mkoptions.c'
--- mkoptions.c 2011-07-07 13:59:05 +0000
+++ mkoptions.c 2011-07-07 17:51:39 +0000
@@ -290,22 +290,20 @@
static char *
tooption(char *name)
{
- static char hbuf[MAXPATHLEN];
- char nbuf[MAXPATHLEN];
+ char *nbuf;
struct opt_list *po;
/* "cannot happen"? the otab list should be complete.. */
- (void)strlcpy(nbuf, "options.h", sizeof(nbuf));
+ nbuf = "options.h";
SLIST_FOREACH(po, &otab, o_next) {
if (eq(po->o_name, name)) {
- strlcpy(nbuf, po->o_file, sizeof(nbuf));
+ nbuf = po->o_file;
break;
}
}
- (void)strlcpy(hbuf, path(nbuf), sizeof(hbuf));
- return (hbuf);
+ return (path(nbuf));
}
@@ -363,7 +361,7 @@
{
FILE *fp;
char *wd, *this, *val;
- char genopt[MAXPATHLEN];
+ char *genopt;
fp = fopen(fname, "r");
if (fp == 0)
@@ -387,7 +385,7 @@
exit(1);
}
char *s = ns(this);
- (void)snprintf(genopt, sizeof(genopt), "opt_%s.h",
+ (void)asprintf(&genopt, "opt_%s.h",
lower(s));
val = genopt;
free(s);
@@ -399,6 +397,7 @@
update_option(this, val, flags);
}
(void)fclose(fp);
+ free(genopt);
return (1);
}
@@ -408,16 +407,17 @@
static void
read_options(void)
{
- char fname[MAXPATHLEN];
+ char *fname;
SLIST_INIT(&otab);
read_option_file("../../conf/options", 0);
- (void)snprintf(fname, sizeof fname, "../../conf/options.%s",
+ (void)asprintf(&fname, "../../conf/options.%s",
machinename);
if (!read_option_file(fname, 0)) {
- (void)snprintf(fname, sizeof fname, "options.%s", machinename);
+ (void)sprintf(fname, "options.%s", machinename);
read_option_file(fname, 0);
}
+ free(fname);
read_option_file("../../conf/options-compat", OL_ALIAS);
}
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