diff --git a/lib/libc/stdio/fvwrite.c b/lib/libc/stdio/fvwrite.c index 50b32b8eca6e..2a161859afa9 100644 --- a/lib/libc/stdio/fvwrite.c +++ b/lib/libc/stdio/fvwrite.c @@ -1,207 +1,216 @@ /*- * SPDX-License-Identifier: BSD-3-Clause * * Copyright (c) 1990, 1993 * The Regents of the University of California. All rights reserved. * * This code is derived from software contributed to Berkeley by * Chris Torek. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. Neither the name of the University nor the names of its contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. */ #if defined(LIBC_SCCS) && !defined(lint) static char sccsid[] = "@(#)fvwrite.c 8.1 (Berkeley) 6/4/93"; #endif /* LIBC_SCCS and not lint */ #include __FBSDID("$FreeBSD$"); #include #include #include #include "local.h" #include "fvwrite.h" /* * Write some memory regions. Return zero on success, EOF on error. * * This routine is large and unsightly, but most of the ugliness due * to the three different kinds of output buffering is handled here. */ int __sfvwrite(FILE *fp, struct __suio *uio) { size_t len; + unsigned char *old_p; char *p; struct __siov *iov; int w, s; char *nl; int nlknown, nldist; if (uio->uio_resid == 0) return (0); /* make sure we can write */ if (prepwrite(fp) != 0) return (EOF); #define MIN(a, b) ((a) < (b) ? (a) : (b)) #define COPY(n) (void)memcpy((void *)fp->_p, (void *)p, (size_t)(n)) iov = uio->uio_iov; p = iov->iov_base; len = iov->iov_len; iov++; #define GETIOV(extra_work) \ while (len == 0) { \ extra_work; \ p = iov->iov_base; \ len = iov->iov_len; \ iov++; \ } if (fp->_flags & __SNBF) { /* * Unbuffered: write up to BUFSIZ bytes at a time. */ do { GETIOV(;); w = _swrite(fp, p, MIN(len, BUFSIZ)); if (w <= 0) goto err; p += w; len -= w; } while ((uio->uio_resid -= w) != 0); } else if ((fp->_flags & __SLBF) == 0) { /* * Fully buffered: fill partially full buffer, if any, * and then flush. If there is no partial buffer, write * one _bf._size byte chunk directly (without copying). * * String output is a special case: write as many bytes * as fit, but pretend we wrote everything. This makes * snprintf() return the number of bytes needed, rather * than the number used, and avoids its write function * (so that the write function can be invalid). */ do { GETIOV(;); if ((fp->_flags & (__SALC | __SSTR)) == (__SALC | __SSTR) && fp->_w < len) { size_t blen = fp->_p - fp->_bf._base; /* * Alloc an extra 128 bytes (+ 1 for NULL) * so we don't call realloc(3) so often. */ fp->_w = len + 128; fp->_bf._size = blen + len + 128; fp->_bf._base = reallocf(fp->_bf._base, fp->_bf._size + 1); if (fp->_bf._base == NULL) goto err; fp->_p = fp->_bf._base + blen; } w = fp->_w; if (fp->_flags & __SSTR) { if (len < w) w = len; if (w > 0) { COPY(w); /* copy MIN(fp->_w,len), */ fp->_w -= w; fp->_p += w; } w = len; /* but pretend copied all */ } else if (fp->_p > fp->_bf._base && len > w) { /* fill and flush */ COPY(w); /* fp->_w -= w; */ /* unneeded */ fp->_p += w; - if (__fflush(fp)) + old_p = fp->_p; + if (__fflush(fp) == EOF) { + if (old_p == fp->_p) + fp->_p -= w; goto err; + } } else if (len >= (w = fp->_bf._size)) { /* write directly */ w = _swrite(fp, p, w); if (w <= 0) goto err; } else { /* fill and done */ w = len; COPY(w); fp->_w -= w; fp->_p += w; } p += w; len -= w; } while ((uio->uio_resid -= w) != 0); } else { /* * Line buffered: like fully buffered, but we * must check for newlines. Compute the distance * to the first newline (including the newline), * or `infinity' if there is none, then pretend * that the amount to write is MIN(len,nldist). */ nlknown = 0; nldist = 0; /* XXX just to keep gcc happy */ do { GETIOV(nlknown = 0); if (!nlknown) { nl = memchr((void *)p, '\n', len); nldist = nl ? nl + 1 - p : len + 1; nlknown = 1; } s = MIN(len, nldist); w = fp->_w + fp->_bf._size; if (fp->_p > fp->_bf._base && s > w) { COPY(w); /* fp->_w -= w; */ fp->_p += w; - if (__fflush(fp)) + old_p = fp->_p; + if (__fflush(fp) == EOF) { + if (old_p == fp->_p) + fp->_p -= w; goto err; + } } else if (s >= (w = fp->_bf._size)) { w = _swrite(fp, p, w); if (w <= 0) goto err; } else { w = s; COPY(w); fp->_w -= w; fp->_p += w; } if ((nldist -= w) == 0) { /* copied the newline: flush and forget */ if (__fflush(fp)) goto err; nlknown = 0; } p += w; len -= w; } while ((uio->uio_resid -= w) != 0); } return (0); err: fp->_flags |= __SERR; return (EOF); }