From f9123b5003e62b6e54996076e860f23aee9a0593 Mon Sep 17 00:00:00 2001 From: Adhemerval Zanella Date: Tue, 26 Apr 2016 17:40:25 -0300 Subject: libio: Update internal fmemopen position after write (BZ #20005) Current GLIBC fmemopen fails with a simple testcase: char buffer[500] = "x"; FILE *stream; stream = fmemopen(buffer, 500, "r+"); fwrite("fish",sizeof(char),5,stream); printf("pos-1:%ld\n",ftell(stream)); fflush(stream); printf("pos-2:%ld\n",ftell(stream)); It returns: pos-1:5 pos-2:0 Where it should return: pos-1:5 pos-2:5 This is due the internal write function does not correctly update the internal object position state and then the seek operation returns a wrong value. This patch fixes it. It fixes both BZ #20005 and BZ #19230 (marked as duplicated). A new test is added to check for such case. Tested on x86_64 and i686. * libio/fmemopen.c (fmemopen_write): Update internal position after write. * stdio-common/Makefile (tests): Add tst-fmemopen4.c. * stdio-common/tst-fmemopen4.c: New file.. --- ChangeLog | 8 +++++ libio/fmemopen.c | 6 ++-- stdio-common/Makefile | 2 +- stdio-common/tst-fmemopen4.c | 71 ++++++++++++++++++++++++++++++++++++++++++++ 4 files changed, 83 insertions(+), 4 deletions(-) create mode 100644 stdio-common/tst-fmemopen4.c diff --git a/ChangeLog b/ChangeLog index 5d6ea9e376..6fda4a4aff 100644 --- a/ChangeLog +++ b/ChangeLog @@ -1,3 +1,11 @@ +2016-04-26 Adhemerval Zanella + + [BZ #20005] + * libio/fmemopen.c (fmemopen_write): Update internal position after + write. + * stdio-common/Makefile (tests): Add tst-fmemopen4.c. + * stdio-common/tst-fmemopen4.c: New file.. + 2016-04-26 Joseph Myers [BZ #19996] diff --git a/libio/fmemopen.c b/libio/fmemopen.c index 23b5c5fea8..9264b724ee 100644 --- a/libio/fmemopen.c +++ b/libio/fmemopen.c @@ -86,10 +86,10 @@ fmemopen_write (void *cookie, const char *b, size_t s) memcpy (&(c->buffer[pos]), b, s); - pos += s; - if ((size_t) pos > c->maxpos) + c->pos += s; + if ((size_t) c->pos > c->maxpos) { - c->maxpos = pos; + c->maxpos = c->pos; if (addnullc) c->buffer[c->maxpos] = '\0'; } diff --git a/stdio-common/Makefile b/stdio-common/Makefile index 6c597c1926..4c4834bea0 100644 --- a/stdio-common/Makefile +++ b/stdio-common/Makefile @@ -58,7 +58,7 @@ tests := tstscanf test_rdwr test-popen tstgetln test-fseek \ scanf16 scanf17 tst-setvbuf1 tst-grouping bug23 bug24 \ bug-vfprintf-nargs tst-long-dbl-fphex tst-fphex-wide tst-sprintf3 \ bug25 tst-printf-round bug23-2 bug23-3 bug23-4 bug26 tst-fmemopen3 \ - tst-printf-bz18872 tst-vfprintf-width-prec + tst-printf-bz18872 tst-vfprintf-width-prec tst-fmemopen4 test-srcs = tst-unbputc tst-printf diff --git a/stdio-common/tst-fmemopen4.c b/stdio-common/tst-fmemopen4.c new file mode 100644 index 0000000000..e24f1cacd9 --- /dev/null +++ b/stdio-common/tst-fmemopen4.c @@ -0,0 +1,71 @@ +/* fmemopen tests for BZ#1930 and BZ#20005. + Copyright (C) 2016 Free Software Foundation, Inc. + This file is part of the GNU C Library. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, see + . */ + +#include +#include +#include +#include + + +/* Check if fflush does not reset the file position. */ +static int +do_test (void) +{ + char buffer[500] = "x"; + + FILE *stream = fmemopen (buffer, sizeof (buffer), "r+"); + if (stream == NULL) + { + printf ("error: fmemopen could not open stream\n"); + return 1; + } + + const char test[] = "test"; + + size_t r = fwrite (test, sizeof (char), sizeof (test), stream); + if (r != sizeof (test)) + { + printf ("error: fwrite returned %zu, expected %zu\n", r, sizeof(test)); + return 1; + } + + r = ftell (stream); + if (r != sizeof (test)) + { + printf ("error: ftell return %zu, expected %zu\n", r, sizeof(test)); + return 1; + } + + if (fflush (stream) != 0) + { + printf ("error: fflush failed\n"); + return 1; + } + + r = ftell (stream); + if (r != sizeof (test)) + { + printf ("error: ftell return %zu, expected %zu\n", r, sizeof(test)); + return 1; + } + + return 0; +} + +#define TEST_FUNCTION do_test () +#include "../test-skeleton.c" -- cgit v1.2.3