dd: fix bug where we assume count=INT_MAX when count is unspecified;
shrink dd while at it function old new delta dd_main 1453 1368 -85 ------------------------------------------------------------------------------ (add/remove: 0/0 grow/shrink: 0/1 up/down: 0/-85) Total: -85 bytes text data bss dec hex filename 669216 2668 13616 685500 a75bc busybox_old 669128 2668 13616 685412 a7564 busybox_unstripped
This commit is contained in:
Denis Vlasenko
parent
1d10aaf116
commit
7587870617
@ -32,6 +32,9 @@ struct globals {
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off_t out_full, out_part, in_full, in_part;
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};
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#define G (*(struct globals*)&bb_common_bufsiz1)
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/* We have to zero it out because of NOEXEC */
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#define INIT_G() memset(&G, 0, sizeof(G))
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static void dd_output_status(int ATTRIBUTE_UNUSED cur_signal)
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{
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@ -73,10 +76,11 @@ int dd_main(int argc, char **argv);
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int dd_main(int argc, char **argv)
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{
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enum {
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SYNC_FLAG = 1 << 0,
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NOERROR = 1 << 1,
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TRUNC_FLAG = 1 << 2,
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TWOBUFS_FLAG = 1 << 3,
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FLAG_SYNC = 1 << 0,
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FLAG_NOERROR = 1 << 1,
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FLAG_NOTRUNC = 1 << 2,
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FLAG_TWOBUFS = 1 << 3,
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FLAG_COUNT = 1 << 4,
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};
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static const char keywords[] =
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"bs=\0""count=\0""seek=\0""skip=\0""if=\0""of=\0"
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@ -100,25 +104,41 @@ int dd_main(int argc, char **argv)
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OP_conv_noerror,
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#endif
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};
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int flags = TRUNC_FLAG;
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size_t oc = 0, ibs = 512, obs = 512;
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size_t ibs = 512, obs = 512;
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ssize_t n, w;
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off_t seek = 0, skip = 0, count = OFF_T_MAX;
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int ifd, ofd;
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const char *infile = NULL, *outfile = NULL;
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char *ibuf, *obuf;
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/* And these are all zeroed at once! */
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struct {
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int flags;
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int ifd, ofd;
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size_t oc;
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off_t count;
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off_t seek, skip;
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const char *infile, *outfile;
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#if ENABLE_FEATURE_DD_SIGNAL_HANDLING
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struct sigaction sigact;
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#endif
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} Z;
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#define flags (Z.flags )
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#define ifd (Z.ifd )
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#define ofd (Z.ofd )
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#define oc (Z.oc )
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#define count (Z.count )
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#define seek (Z.seek )
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#define skip (Z.skip )
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#define infile (Z.infile )
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#define outfile (Z.outfile)
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#define sigact (Z.sigact )
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memset(&G, 0, sizeof(G)); /* because of NOEXEC */
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memset(&Z, 0, sizeof(Z));
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INIT_G();
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if (ENABLE_FEATURE_DD_SIGNAL_HANDLING) {
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struct sigaction sa;
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memset(&sa, 0, sizeof(sa));
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sa.sa_handler = dd_output_status;
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sa.sa_flags = SA_RESTART;
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sigemptyset(&sa.sa_mask);
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sigaction(SIGUSR1, &sa, 0);
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}
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#if ENABLE_FEATURE_DD_SIGNAL_HANDLING
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sigact.sa_handler = dd_output_status;
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sigact.sa_flags = SA_RESTART;
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sigemptyset(&sigact.sa_mask);
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sigaction(SIGUSR1, &sigact, NULL);
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#endif
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for (n = 1; n < argc; n++) {
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smalluint key_len;
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@ -162,11 +182,11 @@ int dd_main(int argc, char **argv)
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if (what < OP_conv_notrunc)
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bb_error_msg_and_die(bb_msg_invalid_arg, arg, "conv");
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if (what == OP_conv_notrunc)
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flags &= ~TRUNC_FLAG;
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flags |= FLAG_NOTRUNC;
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if (what == OP_conv_sync)
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flags |= SYNC_FLAG;
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flags |= FLAG_SYNC;
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if (what == OP_conv_noerror)
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flags |= NOERROR;
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flags |= FLAG_NOERROR;
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if (!key) /* no ',' left, so this was the last specifier */
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break;
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arg = key + 1; /* skip this keyword and ',' */
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@ -180,6 +200,7 @@ int dd_main(int argc, char **argv)
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}
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/* These can be large: */
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if (what == OP_count) {
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flags |= FLAG_COUNT;
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count = XATOU_SFX(arg, dd_suffixes);
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continue;
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}
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@ -201,24 +222,24 @@ int dd_main(int argc, char **argv)
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//XXX:FIXME for huge ibs or obs, malloc'ing them isn't the brightest idea ever
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ibuf = obuf = xmalloc(ibs);
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if (ibs != obs) {
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flags |= TWOBUFS_FLAG;
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flags |= FLAG_TWOBUFS;
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obuf = xmalloc(obs);
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}
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if (infile != NULL)
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ifd = xopen(infile, O_RDONLY);
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else {
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ifd = STDIN_FILENO;
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/* ifd = STDIN_FILENO; - it's zero and it's already there */
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infile = bb_msg_standard_input;
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}
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if (outfile != NULL) {
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int oflag = O_WRONLY | O_CREAT;
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if (!seek && (flags & TRUNC_FLAG))
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if (!seek && !(flags & FLAG_NOTRUNC))
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oflag |= O_TRUNC;
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ofd = xopen(outfile, oflag);
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if (seek && (flags & TRUNC_FLAG)) {
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if (seek && !(flags & FLAG_NOTRUNC)) {
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if (ftruncate(ofd, seek * obs) < 0) {
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struct stat st;
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@ -247,14 +268,14 @@ int dd_main(int argc, char **argv)
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goto die_outfile;
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}
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while (G.in_full + G.in_part != count) {
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if (flags & NOERROR) /* Pre-zero the buffer when for NOERROR */
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memset(ibuf, '\0', ibs);
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while ((flags & FLAG_COUNT) && (G.in_full + G.in_part != count)) {
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if (flags & FLAG_NOERROR) /* Pre-zero the buffer if conv=noerror */
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memset(ibuf, 0, ibs);
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n = safe_read(ifd, ibuf, ibs);
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if (n == 0)
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break;
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if (n < 0) {
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if (flags & NOERROR) {
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if (flags & FLAG_NOERROR) {
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n = ibs;
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bb_perror_msg("%s", infile);
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} else
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@ -264,12 +285,12 @@ int dd_main(int argc, char **argv)
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G.in_full++;
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else {
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G.in_part++;
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if (flags & SYNC_FLAG) {
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if (flags & FLAG_SYNC) {
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memset(ibuf + n, '\0', ibs - n);
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n = ibs;
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}
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}
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if (flags & TWOBUFS_FLAG) {
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if (flags & FLAG_TWOBUFS) {
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char *tmp = ibuf;
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while (n) {
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size_t d = obs - oc;
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