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d67cef242

Denis Vlasenko

2007-06-13

FAILED Duration: 12s

Subject

hush: fix read builtin to not read ahead past eol and to not use insane amounts of stack. Testsuite updated.

Binary

No binary (build failed)

Architecture & Compiler Flags

Architecture: x86_64-linux-gnu Compiler: gcc (Ubuntu 11.4.0-1ubuntu1~22.04.3) 11.4.0

—

Build Log

(log yok)

Commit Diff GitHub →

include/libbb.h +4 -0 libbb/read.c +42 -11 modutils/insmod.c +4 -3 modutils/modprobe.c +1 -1 shell/README +3 -0 shell/ash.c +2 -2 shell/hush.c +3 -13 shell/hush_test/hush-misc/read.right +4 -0 shell/hush_test/hush-misc/read.tests +4 -0 util-linux/readprofile.c +1 -1

include/libbb.h+4 -0

@@ -400,7 +400,11 @@ extern ssize_t safe_read(int fd, void *buf, size_t count);
	extern ssize_t full_read(int fd, void *buf, size_t count);
	extern void xread(int fd, void *buf, size_t count);
	extern unsigned char xread_char(int fd);
+	// Read one line a-la fgets. Uses one read(), works only on seekable streams
	extern char reads(int fd, char buf, size_t count);
+	// Read one line a-la fgets. Reads byte-by-byte.
+	// Useful when it is important to not read ahead.
+	extern char xmalloc_reads(int fd, char pfx);
	extern ssize_t read_close(int fd, void *buf, size_t count);
	extern ssize_t open_read_close(const char filename, void buf, size_t count);
	extern void xmalloc_open_read_close(const char filename, size_t *sizep);

libbb/read.c+42 -11

@@ -38,10 +38,8 @@ ssize_t full_read(int fd, void *buf, size_t len)

	if (cc < 0)
	return cc; /* read() returns -1 on failure. */
-
	if (cc == 0)
	break;
-
	buf = ((char *)buf) + cc;
	total += cc;
	len -= cc;
@@ -64,9 +62,7 @@ void xread(int fd, void *buf, size_t count)
	unsigned char xread_char(int fd)
	{
	char tmp;
-
	xread(fd, &tmp, 1);
-
	return tmp;
	}

@@ -95,6 +91,37 @@ char reads(int fd, char buffer, size_t size)
	return buffer;
	}

+	// Read one line a-la fgets. Reads byte-by-byte.
+	// Useful when it is important to not read ahead.
+	char xmalloc_reads(int fd, char buf)
+	{
+	char *p;
+	int sz = buf ? strlen(buf) : 0;
+
+	goto jump_in;
+	while (1) {
+	if (p - buf == sz) {
+	jump_in:
+	buf = xrealloc(buf, sz + 128);
+	p = buf + sz;
+	sz += 128;
+	}
+	if (safe_read(fd, p, 1) != 1) { /* EOF/error */
+	if (p == buf) {
+	/* we read nothing [and buf was NULL initially] */
+	free(buf);
+	return NULL;
+	}
+	break;
+	}
+	if (*p == '\n')
+	break;
+	p++;
+	}
+	*p++ = '\0';
+	return xrealloc(buf, p - buf);
+	}
+
	ssize_t read_close(int fd, void *buf, size_t size)
	{
	int e;
@@ -113,25 +140,29 @@ ssize_t open_read_close(const char filename, void buf, size_t size)
	return read_close(fd, buf, size);
	}

+	// Read (potentially big) files in one go. File size is estimated by
+	// lseek to end.
	void xmalloc_open_read_close(const char filename, size_t *sizep)
	{
	char *buf;
	size_t size = sizep ? *sizep : INT_MAX;
-	int fd = xopen(filename, O_RDONLY);
+	int fd;
+	off_t len;
+
+	fd = xopen(filename, O_RDONLY);
	/* /proc/N/stat files report len 0 here */
	/* In order to make such files readable, we add small const */
-	off_t len = xlseek(fd, 0, SEEK_END) + 256;
+	len = xlseek(fd, 0, SEEK_END) \| 0x3ff; /* + up to 1k */
	xlseek(fd, 0, SEEK_SET);
-
-	if (len > size)
-	bb_error_msg_and_die("file '%s' is too big", filename);
-	size = len;
+	if (len < size)
+	size = len;
	buf = xmalloc(size + 1);
	size = read_close(fd, buf, size);
	if ((ssize_t)size < 0)
	bb_perror_msg_and_die("'%s'", filename);
	xrealloc(buf, size + 1);
	buf[size] = '\0';
-	if (sizep) *sizep = size;
+	if (sizep)
+	*sizep = size;
	return buf;
	}

modutils/insmod.c+4 -3

@@ -4262,6 +4262,7 @@ int insmod_ng_main(int argc, char **argv)
	{
	long ret;
	size_t len;
+	int optlen;
	void *map;
	char filename, options;

@@ -4270,12 +4271,12 @@ int insmod_ng_main(int argc, char **argv)
	bb_show_usage();

	/* Rest is options */
-	options = xstrdup("");
+	options = xzalloc(1);
+	optlen = 0;
	while (*++argv) {
-	int optlen = strlen(options);
	options = xrealloc(options, optlen + 2 + strlen(*argv) + 2);
	/* Spaces handled by "" pairs, but no way of escaping quotes */
-	sprintf(options + optlen, (strchr(argv,' ') ? "\"%s\" " : "%s "), argv);
+	optlen += sprintf(options + optlen, (strchr(argv,' ') ? "\"%s\" " : "%s "), argv);
	}

	#if 0

modutils/modprobe.c+1 -1

@@ -234,7 +234,7 @@ static void include_conf(struct dep_t first, struct dep_t current, char *buf
	{
	int continuation_line = 0;

-	// alias parsing is not 100% correct (no correct handling of continuation lines within an alias) !
+	// alias parsing is not 100% correct (no correct handling of continuation lines within an alias)!

	while (reads(fd, buffer, buflen)) {
	int l;

shell/README+3 -0

@@ -1,5 +1,8 @@
	Various bits of what is known about busybox shells, in no particular order.

+	2007-06-13
+	hush: exec <"$1" doesn't do parameter subst
+
	2007-05-24
	hush: environment-related memory leak plugged, with net code size
	decrease.

shell/ash.c+2 -2

@@ -11567,8 +11567,8 @@ readcmd(int argc, char **argv)
	#endif
	#if ENABLE_ASH_READ_TIMEOUT
	if (ts.tv_sec \|\| ts.tv_usec) {
-	FD_ZERO (&set);
-	FD_SET (0, &set);
+	FD_ZERO(&set);
+	FD_SET(0, &set);

	i = select(FD_SETSIZE, &set, NULL, NULL, &ts);
	if (!i) {

shell/hush.c+3 -13

@@ -942,21 +942,11 @@ static int builtin_pwd(char **argv ATTRIBUTE_UNUSED)
	/* built-in 'read VAR' handler */
	static int builtin_read(char **argv)
	{
-	char string[BUFSIZ];
-	char *p;
+	char *string;
	const char *name = argv[1] ? argv[1] : "REPLY";
-	int name_len = strlen(name);

-	if (name_len >= sizeof(string) - 2)
-	return EXIT_FAILURE;
-	strcpy(string, name);
-	p = string + name_len;
-	*p++ = '=';
-	p = '\0'; / In case stdin has only EOF */
-	/* read string. name_len+1 chars are already used by 'name=' */
-	fgets(p, sizeof(string) - 1 - name_len, stdin);
-	chomp(p);
-	return set_local_var(xstrdup(string), 0);
+	string = xmalloc_reads(STDIN_FILENO, xasprintf("%s=", name));
+	return set_local_var(string, 0);
	}

	/* built-in 'set [VAR=value]' handler */

shell/hush_test/hush-misc/read.right+4 -0

@@ -0,0 +1,4 @@
+	read
+	cat
+	echo "REPLY=$REPLY"
+	REPLY=exec <read.tests

shell/hush_test/hush-misc/read.tests+4 -0

@@ -0,0 +1,4 @@
+	exec <read.tests
+	read
+	cat
+	echo "REPLY=$REPLY"

util-linux/readprofile.c+1 -1

@@ -99,7 +99,7 @@ int readprofile_main(int argc, char **argv)
	/*
	* Use an fd for the profiling buffer, to skip stdio overhead
	*/
-	len = INT_MAX;
+	len = MAXINT(ssize_t);
	buf = xmalloc_open_read_close(proFile, &len);
	if (!optNative) {
	int entries = len/sizeof(*buf);