c6758a07c

Denis Vlasenko

2007-04-10

FAILED Duration: 11s

Subject

make compressed help code NOMMU- and NOFORK-friendly - no forking anymore, bunzip2 unpack routine now does all it in memory.

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 →

applets/applets.c +28 -39 archival/gzip.c +1 -1 archival/libunarchive/decompress_bunzip2.c +36 -22 archival/libunarchive/decompress_unzip.c +1 -1 archival/libunarchive/get_header_tar_gz.c +0 -2 coreutils/cksum.c +1 -2 include/libbb.h +3 -2 include/unarchive.h +5 -0 libbb/crc32.c +4 -3 libbb/vfork_daemon_rexec.c +46 -98 libbb/xfuncs.c +9 -0

applets/applets.c+28 -39

@@ -403,44 +403,32 @@ static void check_suid(const struct bb_applet *applet)

	static const char *unpack_usage_messages(void)
	{
-	int input[2], output[2], pid;
-	char *buf;
-
-	if (pipe(input) < 0 \|\| pipe(output) < 0)
-	exit(1);
-
-	//TODO: not NOMMU friendly!
-	pid = fork();
-	switch (pid) {
-	case -1: /* error */
-	exit(1);
-	case 0: /* child */
-	close(input[1]);
-	close(output[0]);
-	uncompressStream(input[0], output[1]);
-	exit(0);
-	}
-	/* parent */
-
-	close(input[0]);
-	close(output[1]);
-	pid = fork();
-	switch (pid) {
-	case -1: /* error */
-	exit(1);
-	case 0: /* child */
-	full_write(input[1], packed_usage, sizeof(packed_usage));
-	exit(0);
-	}
-	/* parent */
-	close(input[1]);
+	char *outbuf = NULL;
+	bunzip_data *bd;
+	int i;

-	buf = xmalloc(SIZEOF_usage_messages);
-	full_read(output[0], buf, SIZEOF_usage_messages);
-	return buf;
+	i = start_bunzip(&bd,
+	/* src_fd: */ -1,
+	/* inbuf: */ packed_usage,
+	/* len: */ sizeof(packed_usage));
+	/* read_bunzip can longjmp to start_bunzip, and ultimately
+	* end up here with i != 0 on read data errors! Not trivial */
+	if (!i) {
+	/* Cannot use xmalloc: will leak bd in NOFORK case! */
+	outbuf = malloc_or_warn(SIZEOF_usage_messages);
+	if (outbuf)
+	read_bunzip(bd, outbuf, SIZEOF_usage_messages);
+	}
+	dealloc_bunzip(bd);
+	return outbuf;
	}
+	#define dealloc_usage_messages(s) free(s)
+
	#else
+
	#define unpack_usage_messages() usage_messages
+	#define dealloc_usage_messages(s) ((void)(s))
+
	#endif /* FEATURE_COMPRESS_USAGE */


@@ -448,22 +436,23 @@ void bb_show_usage(void)
	{
	if (ENABLE_SHOW_USAGE) {
	const char *format_string;
-	const char *usage_string = unpack_usage_messages();
+	const char *p;
+	const char *usage_string = p = unpack_usage_messages();
	int i;

	i = current_applet - applets;
	while (i) {
-	while (*usage_string++) continue;
+	while (*p++) continue;
	i--;
	}

	format_string = "%s\n\nUsage: %s %s\n\n";
-	if (*usage_string == '\b')
+	if (*p == '\b')
	format_string = "%s\n\nNo help available.\n\n";
	fprintf(stderr, format_string, bb_msg_full_version,
-	applet_name, usage_string);
+	applet_name, p);
+	dealloc_usage_messages((char*)usage_string);
	}
-
	xfunc_die();
	}

archival/gzip.c+1 -1

@@ -2079,7 +2079,7 @@ int gzip_main(int argc, char **argv)
	ALLOC(ush, G1.prev, 1L << BITS);

	/* Initialise the CRC32 table */
-	G1.crc_32_tab = crc32_filltable(0);
+	G1.crc_32_tab = crc32_filltable(NULL, 0);

	return bbunpack(argv, make_new_name_gzip, pack_gzip);
	}

archival/libunarchive/decompress_bunzip2.c+36 -22

@@ -62,34 +62,31 @@ struct group_data {
	/* Structure holding all the housekeeping data, including IO buffers and
	memory that persists between calls to bunzip */

-	typedef struct {
+	struct bunzip_data {
	/* State for interrupting output loop */
-
	int writeCopies, writePos, writeRunCountdown, writeCount, writeCurrent;

	/* I/O tracking data (file handles, buffers, positions, etc.) */
-
	int in_fd, out_fd, inbufCount, inbufPos /, outbufPos/;
	unsigned char inbuf /,outbuf/;
	unsigned inbufBitCount, inbufBits;

	/* The CRC values stored in the block header and calculated from the data */
-
	uint32_t headerCRC, totalCRC, writeCRC;
-	uint32_t *crc32Table;
-	/* Intermediate buffer and its size (in bytes) */

+	/* Intermediate buffer and its size (in bytes) */
	unsigned *dbuf, dbufSize;

-	/* These things are a bit too big to go on the stack */
+	/* For I/O error handling */
+	jmp_buf jmpbuf;

+	/* Big things go last (register-relative addressing can be larger for big offsets */
+	uint32_t crc32Table[256];
	unsigned char selectors[32768]; /* nSelectors=15 bits */
	struct group_data groups[MAX_GROUPS]; /* Huffman coding tables */
+	};
+	/* typedef struct bunzip_data bunzip_data; -- done in .h file */

-	/* For I/O error handling */
-
-	jmp_buf jmpbuf;
-	} bunzip_data;

	/* Return the next nnn bits of input. All reads from the compressed input
	are done through this function. All reads are big endian */
@@ -106,6 +103,7 @@ static unsigned get_bits(bunzip_data *bd, char bits_wanted)
	/* If we need to read more data from file into byte buffer, do so */

	if (bd->inbufPos == bd->inbufCount) {
+	/* if "no input fd" case: in_fd == -1, read fails, we jump */
	bd->inbufCount = read(bd->in_fd, bd->inbuf, IOBUF_SIZE);
	if (bd->inbufCount <= 0)
	longjmp(bd->jmpbuf, RETVAL_UNEXPECTED_INPUT_EOF);
@@ -519,7 +517,7 @@ static int get_next_block(bunzip_data *bd)
	are ignored, data is written to out_fd and return is RETVAL_OK or error.
	*/

-	static int read_bunzip(bunzip_data bd, char outbuf, int len)
+	int read_bunzip(bunzip_data bd, char outbuf, int len)
	{
	const unsigned *dbuf;
	int pos, current, previous, gotcount;
@@ -627,11 +625,16 @@ static int read_bunzip(bunzip_data bd, char outbuf, int len)
	goto decode_next_byte;
	}

+
	/* Allocate the structure, read file header. If in_fd==-1, inbuf must contain
	a complete bunzip file (len bytes long). If in_fd!=-1, inbuf and len are
	ignored, and data is read from file handle into temporary buffer. */

-	static int start_bunzip(bunzip_data *bdp, int in_fd, unsigned char inbuf,
+	/* Because bunzip2 is used for help text unpacking, and because bb_show_usage()
+	should work for NOFORK applets too, we must be extremely careful to not leak
+	any allocations! */
+
+	int start_bunzip(bunzip_data *bdp, int in_fd, const unsigned char inbuf,
	int len)
	{
	bunzip_data *bd;
@@ -653,14 +656,15 @@ static int start_bunzip(bunzip_data *bdp, int in_fd, unsigned char inbuf,

	bd->in_fd = in_fd;
	if (-1 == in_fd) {
-	bd->inbuf = inbuf;
+	/* in this case, bd->inbuf is read-only */
+	bd->inbuf = (void)inbuf; / cast away const-ness */
	bd->inbufCount = len;
	} else
	bd->inbuf = (unsigned char *)(bd + 1);

	/* Init the CRC32 table (big endian) */

-	bd->crc32Table = crc32_filltable(1);
+	crc32_filltable(bd->crc32Table, 1);

	/* Setup for I/O error handling via longjmp */

@@ -670,19 +674,30 @@ static int start_bunzip(bunzip_data *bdp, int in_fd, unsigned char inbuf,
	/* Ensure that file starts with "BZh['1'-'9']." */

	i = get_bits(bd, 32);
-	if (((unsigned)(i - BZh0 - 1)) >= 9) return RETVAL_NOT_BZIP_DATA;
+	if ((unsigned)(i - BZh0 - 1) >= 9) return RETVAL_NOT_BZIP_DATA;

	/* Fourth byte (ascii '1'-'9'), indicates block size in units of 100k of
	uncompressed data. Allocate intermediate buffer for block. */

	bd->dbufSize = 100000 * (i - BZh0);

-	bd->dbuf = xmalloc(bd->dbufSize * sizeof(int));
+	/* Cannot use xmalloc - may leak bd in NOFORK case! */
+	bd->dbuf = malloc_or_warn(bd->dbufSize * sizeof(int));
+	if (!bd->dbuf) {
+	free(bd);
+	xfunc_die();
+	}
	return RETVAL_OK;
	}

-	/* Example usage: decompress src_fd to dst_fd. (Stops at end of bzip data,
-	not end of file.) */
+	void dealloc_bunzip(bunzip_data *bd)
+	{
+	free(bd->dbuf);
+	free(bd);
+	}
+
+
+	/* Decompress src_fd to dst_fd. Stops at end of bzip data, not end of file. */

	USE_DESKTOP(long long) int
	uncompressStream(int src_fd, int dst_fd)
@@ -693,7 +708,7 @@ uncompressStream(int src_fd, int dst_fd)
	int i;

	outbuf = xmalloc(IOBUF_SIZE);
-	i = start_bunzip(&bd, src_fd, 0, 0);
+	i = start_bunzip(&bd, src_fd, NULL, 0);
	if (!i) {
	for (;;) {
	i = read_bunzip(bd, outbuf, IOBUF_SIZE);
@@ -719,8 +734,7 @@ uncompressStream(int src_fd, int dst_fd)
	} else {
	bb_error_msg("decompression failed");
	}
-	free(bd->dbuf);
-	free(bd);
+	dealloc_bunzip(bd);
	free(outbuf);

	return i ? i : USE_DESKTOP(total_written) + 0;

archival/libunarchive/decompress_unzip.c+1 -1

@@ -1000,7 +1000,7 @@ inflate_unzip_internal(STATE_PARAM int in, int out)
	gunzip_bb = 0;

	/* Create the crc table */
-	gunzip_crc_table = crc32_filltable(0);
+	gunzip_crc_table = crc32_filltable(NULL, 0);
	gunzip_crc = ~0;

	/* Allocate space for buffer */

archival/libunarchive/get_header_tar_gz.c+0 -2

@@ -3,8 +3,6 @@
	* Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
	*/

-	#include <stdlib.h>
-
	#include "libbb.h"
	#include "unarchive.h"

coreutils/cksum.c+1 -2

@@ -11,8 +11,7 @@
	int cksum_main(int argc, char **argv);
	int cksum_main(int argc, char **argv)
	{
-
-	uint32_t *crc32_table = crc32_filltable(1);
+	uint32_t *crc32_table = crc32_filltable(NULL, 1);

	FILE *fp;
	uint32_t crc;

include/libbb.h+3 -2

@@ -403,9 +403,10 @@ extern char xasprintf(const char format, ...) __attribute__ ((format (printf,

	/* dmalloc will redefine these to it's own implementation. It is safe
	* to have the prototypes here unconditionally. */
+	extern void *malloc_or_warn(size_t size);
	extern void *xmalloc(size_t size);
-	extern void xrealloc(void old, size_t size);
	extern void *xzalloc(size_t size);
+	extern void xrealloc(void old, size_t size);

	extern ssize_t safe_read(int fd, void *buf, size_t count);
	extern ssize_t full_read(int fd, void *buf, size_t count);
@@ -862,7 +863,7 @@ void md5_begin(md5_ctx_t *ctx);
	void md5_hash(const void data, size_t length, md5_ctx_t ctx);
	void md5_end(void resbuf, md5_ctx_t *ctx);

-	uint32_t *crc32_filltable(int endian);
+	uint32_t crc32_filltable(uint32_t tbl256, int endian);


	enum { /* DO NOT CHANGE THESE VALUES! cp.c, mv.c, install.c depend on them. */

include/unarchive.h+5 -0

@@ -102,6 +102,11 @@ extern const llist_t find_list_entry(const llist_t list, const char *filename)
	extern const llist_t find_list_entry2(const llist_t list, const char *filename);

	extern USE_DESKTOP(long long) int uncompressStream(int src_fd, int dst_fd);
+	/* A bit of bunzip2 internals are exposed for compressed help support: */
+	typedef struct bunzip_data bunzip_data;
+	int start_bunzip(bunzip_data *bdp, int in_fd, const unsigned char inbuf, int len);
+	int read_bunzip(bunzip_data bd, char outbuf, int len);
+	void dealloc_bunzip(bunzip_data *bd);

	typedef struct inflate_unzip_result {
	off_t bytes_out;

libbb/crc32.c+4 -3

@@ -16,14 +16,15 @@

	#include "libbb.h"

-	uint32_t *crc32_filltable(int endian)
+	uint32_t crc32_filltable(uint32_t crc_table, int endian)
	{
-
-	uint32_t crc_table = xmalloc(256 sizeof(uint32_t));
	uint32_t polynomial = endian ? 0x04c11db7 : 0xedb88320;
	uint32_t c;
	int i, j;

+	if (!crc_table)
+	crc_table = xmalloc(256 * sizeof(uint32_t));
+
	for (i = 0; i < 256; i++) {
	c = endian ? (i << 24) : i;
	for (j = 8; j; j--) {

libbb/vfork_daemon_rexec.c+46 -98

@@ -102,120 +102,68 @@ int wait_pid(int *wstat, int pid)

	int spawn_and_wait(char **argv)
	{
+	#if ENABLE_FEATURE_EXEC_PREFER_APPLETS
	int rc;
+	const struct bb_applet *a = find_applet_by_name(argv[0]);

-	#if ENABLE_FEATURE_EXEC_PREFER_APPLETS
-	{
-	const struct bb_applet *a = find_applet_by_name(argv[0]);
-	if (a && (a->nofork
+	if (a && (a->nofork
	#ifndef BB_NOMMU
-	\|\| a->noexec /* NOEXEC cannot be used on NOMMU */
+	\|\| a->noexec /* NOEXEC cannot be used on NOMMU */
	#endif
-	)) {
-	int argc = 1;
-	char **pp = argv;
-	while (*++pp)
-	argc++;
+	)) {
+	int argc = 1;
+	char **pp = argv;
+	while (*++pp)
+	argc++;
	#ifndef BB_NOMMU
-	if (a->nofork)
+	if (a->nofork)
	#endif
-	{
-	int old_sleep = die_sleep;
-	int old_x = xfunc_error_retval;
-	die_sleep = -1; /* special flag */
-	/* xfunc_die() checks for it */
-
-	rc = setjmp(die_jmp);
-	if (!rc) {
-	const struct bb_applet *old_a = current_applet;
-	current_applet = a;
-	applet_name = a->name;
+	{
+	int old_sleep = die_sleep;
+	int old_x = xfunc_error_retval;
+	die_sleep = -1; /* special flag */
+	/* xfunc_die() checks for it */
+
+	rc = setjmp(die_jmp);
+	if (!rc) {
+	const struct bb_applet *old_a = current_applet;
+	current_applet = a;
+	applet_name = a->name;
	// what else should we save/restore?
-	rc = a->main(argc, argv);
-	current_applet = old_a;
-	applet_name = old_a->name;
-	} else {
-	/* xfunc died in NOFORK applet */
-	if (rc == -111)
-	rc = 0;
-	}
-
-	die_sleep = old_sleep;
-	xfunc_error_retval = old_x;
-	return rc;
+	// TODO: what if applet will mangle argv vector?
+	// xargs needs argv untouched because it frees the vector!
+	// shouldn't we pass a copy?
+	rc = a->main(argc, argv);
+	current_applet = old_a;
+	applet_name = old_a->name;
+	} else {
+	/* xfunc died in NOFORK applet */
+	if (rc == -111)
+	rc = 0;
	}
+
+	die_sleep = old_sleep;
+	xfunc_error_retval = old_x;
+	return rc;
+	}
	#ifndef BB_NOMMU /* MMU only */
-	/* a->noexec is true */
-	rc = fork();
-	if (rc)
-	goto w;
-	/* child */
-	current_applet = a;
-	run_current_applet_and_exit(argc, argv);
+	/* a->noexec is true */
+	rc = fork();
+	if (rc)
+	goto w;
+	/* child */
+	current_applet = a;
+	run_current_applet_and_exit(argc, argv);
	#endif
-	}
-
	}
	rc = spawn(argv);
	w:
-	#else /* !FEATURE_EXEC_PREFER_APPLETS */
-	rc = spawn(argv);
-	#endif /* FEATURE_EXEC_PREFER_APPLETS */
	return wait4pid(rc);
-	}
-
-
-	#if 0 //ndef BB_NOMMU
-	// Die with an error message if we can't daemonize.
-	void xdaemon(int nochdir, int noclose)
-	{
-	if (daemon(nochdir, noclose))
-	bb_perror_msg_and_die("daemon");
-	}
+	#else /* !FEATURE_EXEC_PREFER_APPLETS */
+	return wait4pid(spawn(argv));
	#endif
-
-	#if 0 // def BB_NOMMU
-	void vfork_daemon_rexec(int nochdir, int noclose, char **argv)
-	{
-	int fd;
-
-	/* Maybe we are already re-execed and come here again? */
-	if (re_execed)
-	return;
-
-	setsid();
-
-	if (!nochdir)
-	xchdir("/");
-
-	if (!noclose) {
-	/* if "/dev/null" doesn't exist, bail out! */
-	fd = xopen(bb_dev_null, O_RDWR);
-	dup2(fd, STDIN_FILENO);
-	dup2(fd, STDOUT_FILENO);
-	dup2(fd, STDERR_FILENO);
-	while (fd > 2)
-	close(fd--);
-	}
-
-	switch (vfork()) {
-	case 0: /* child */
-	/* Make certain we are not a session leader, or else we
-	* might reacquire a controlling terminal */
-	if (vfork())
-	_exit(0);
-	/* High-order bit of first char in argv[0] is a hidden
-	* "we have (alrealy) re-execed, don't do it again" flag */
-	argv[0][0] \|= 0x80;
-	execv(CONFIG_BUSYBOX_EXEC_PATH, argv);
-	bb_perror_msg_and_die("exec %s", CONFIG_BUSYBOX_EXEC_PATH);
-	case -1: /* error */
-	bb_perror_msg_and_die("vfork");
-	default: /* parent */
-	exit(0);
-	}
	}
-	#endif /* BB_NOMMU */
+

	#ifdef BB_NOMMU
	void forkexit_or_rexec(char **argv)

libbb/xfuncs.c+9 -0

@@ -20,6 +20,15 @@
	* Since dmalloc's prototypes overwrite the impls here as they are
	* included after these prototypes in libbb.h, all is well.
	*/
+	// Warn if we can't allocate size bytes of memory.
+	void *malloc_or_warn(size_t size)
+	{
+	void *ptr = malloc(size);
+	if (ptr == NULL && size != 0)
+	bb_error_msg(bb_msg_memory_exhausted);
+	return ptr;
+	}
+
	// Die if we can't allocate size bytes of memory.
	void *xmalloc(size_t size)
	{