From 0b727ed4d605d9318cb0d323c88abb0d5a441a9b Mon Sep 17 00:00:00 2001 From: Adhemerval Zanella Date: Thu, 13 Jul 2017 16:43:24 -0300 Subject: libio: Flush stream at freopen (BZ#21037) As POSIX states [1] a freopen call should first flush the stream as if by a call fflush. C99 (n1256) and C11 (n1570) only states the function should first close any file associated with the specific stream. Although current implementation only follow C specification, current BSD and other libc implementation (musl) are in sync with POSIX and fflush the stream. This patch change freopen{64} to fflush the stream before actually reopening it (or returning if the stream does not support reopen). It also changes the Linux implementation to avoid a dynamic allocation on 'fd_to_filename'. Checked on x86_64-linux-gnu. [BZ #21037] * libio/Makefile (tests): Add tst-memstream4 and tst-wmemstream4. * libio/freopen.c (freopen): Sync stream before reopen and adjust to new fd_to_filename interface. * libio/freopen64.c (freopen64): Likewise. * libio/tst-memstream.h: New file. * libio/tst-memstream4.c: Likewise. * libio/tst-wmemstream4.c: Likewise. * sysdeps/generic/fd_to_filename.h (fd_to_filename): Change signature. * sysdeps/unix/sysv/linux/fd_to_filename.h (fd_to_filename): Likewise and remove internal dynamic allocation. [1] http://pubs.opengroup.org/onlinepubs/9699919799/ --- libio/Makefile | 4 +-- libio/freopen.c | 29 +++++++++++---------- libio/freopen64.c | 26 +++++++++++-------- libio/tst-memstream.h | 68 +++++++++++++++++++++++++++++++++++++++++++++++++ libio/tst-memstream4.c | 64 ++++++++++++++++++++++++++++++++++++++++++++++ libio/tst-wmemstream4.c | 20 +++++++++++++++ 6 files changed, 185 insertions(+), 26 deletions(-) create mode 100644 libio/tst-memstream.h create mode 100644 libio/tst-memstream4.c create mode 100644 libio/tst-wmemstream4.c (limited to 'libio') diff --git a/libio/Makefile b/libio/Makefile index cab0eae..8239fba 100644 --- a/libio/Makefile +++ b/libio/Makefile @@ -59,8 +59,8 @@ tests = tst_swprintf tst_wprintf tst_swscanf tst_wscanf tst_getwc tst_putwc \ tst-mmap-eofsync tst-mmap-fflushsync bug-mmap-fflush \ tst-mmap2-eofsync tst-mmap-offend bug-fopena+ bug-wfflush \ bug-ungetc2 bug-ftell bug-ungetc3 bug-ungetc4 tst-fopenloc2 \ - tst-memstream1 tst-memstream2 tst-memstream3 \ - tst-wmemstream1 tst-wmemstream2 tst-wmemstream3 \ + tst-memstream1 tst-memstream2 tst-memstream3 tst-memstream4 \ + tst-wmemstream1 tst-wmemstream2 tst-wmemstream3 tst-wmemstream4 \ bug-memstream1 bug-wmemstream1 \ tst-setvbuf1 tst-popen1 tst-fgetwc bug-wsetpos tst-fseek \ tst-fwrite-error tst-ftell-partial-wide tst-ftell-active-handler \ diff --git a/libio/freopen.c b/libio/freopen.c index abf19e9..6ce74ae 100644 --- a/libio/freopen.c +++ b/libio/freopen.c @@ -24,28 +24,34 @@ This exception applies to code released by its copyright holders in files containing the exception. */ -#include "libioP.h" -#include "stdio.h" +#include #include #include #include -#include +#include #include - -#include +#include FILE * freopen (const char *filename, const char *mode, FILE *fp) { - FILE *result; + FILE *result = NULL; + char fdfilename[FD_TO_FILENAME_SIZE]; + CHECK_FILE (fp, NULL); - if (!(fp->_flags & _IO_IS_FILEBUF)) - return NULL; + _IO_acquire_lock (fp); + /* First flush the stream (failure should be ignored). */ + _IO_SYNC (fp); + + if (!(fp->_flags & _IO_IS_FILEBUF)) + goto end; + int fd = _IO_fileno (fp); - const char *gfilename = (filename == NULL && fd >= 0 - ? fd_to_filename (fd) : filename); + const char *gfilename + = filename != NULL ? filename : fd_to_filename (fd, fdfilename); + fp->_flags2 |= _IO_FLAGS2_NOCLOSE; #if SHLIB_COMPAT (libc, GLIBC_2_0, GLIBC_2_1) if (&_IO_stdin_used == NULL) @@ -101,9 +107,6 @@ freopen (const char *filename, const char *mode, FILE *fp) __close (fd); end: - if (filename == NULL) - free ((char *) gfilename); - _IO_release_lock (fp); return result; } diff --git a/libio/freopen64.c b/libio/freopen64.c index ea7ebd3..055b999 100644 --- a/libio/freopen64.c +++ b/libio/freopen64.c @@ -24,27 +24,33 @@ This exception applies to code released by its copyright holders in files containing the exception. */ -#include "libioP.h" -#include "stdio.h" +#include #include #include #include +#include #include -#include - FILE * freopen64 (const char *filename, const char *mode, FILE *fp) { - FILE *result; + FILE *result = NULL; + char fdfilename[FD_TO_FILENAME_SIZE]; + CHECK_FILE (fp, NULL); - if (!(fp->_flags & _IO_IS_FILEBUF)) - return NULL; + _IO_acquire_lock (fp); + /* First flush the stream (failure should be ignored). */ + _IO_SYNC (fp); + + if (!(fp->_flags & _IO_IS_FILEBUF)) + goto end; + int fd = _IO_fileno (fp); - const char *gfilename = (filename == NULL && fd >= 0 - ? fd_to_filename (fd) : filename); + const char *gfilename + = filename != NULL ? filename : fd_to_filename (fd, fdfilename); + fp->_flags2 |= _IO_FLAGS2_NOCLOSE; _IO_file_close_it (fp); _IO_JUMPS_FILE_plus (fp) = &_IO_file_jumps; @@ -84,8 +90,6 @@ freopen64 (const char *filename, const char *mode, FILE *fp) __close (fd); end: - if (filename == NULL) - free ((char *) gfilename); _IO_release_lock (fp); return result; } diff --git a/libio/tst-memstream.h b/libio/tst-memstream.h new file mode 100644 index 0000000..b9b02bd --- /dev/null +++ b/libio/tst-memstream.h @@ -0,0 +1,68 @@ +/* Common definitions for open_memstream tests. + Copyright (C) 2018 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 +#include +#include + +#include + +#ifdef TEST_WCHAR +# include + +/* Straighforward implementation so tst-memstream3 could use check + fwrite on open_memstream. */ +static size_t __attribute__ ((used)) +fwwrite (const void *ptr, size_t size, size_t nmemb, FILE *arq) +{ + const wchar_t *wcs = (const wchar_t*) (ptr); + for (size_t s = 0; s < size; s++) + { + for (size_t n = 0; n < nmemb; n++) + if (fputwc (wcs[n], arq) == WEOF) + return n; + } + return size * nmemb; +} + +# define CHAR_T wchar_t +# define W(o) L##o +# define OPEN_MEMSTREAM open_wmemstream +# define PRINTF wprintf +# define FWRITE fwwrite +# define FPUTC fputwc +# define FPUTS fputws +# define STRCMP wcscmp +# define STRLEN wcslen +#else +# define CHAR_T char +# define W(o) o +# define OPEN_MEMSTREAM open_memstream +# define PRINTF printf +# define FWRITE fwrite +# define FPUTC fputc +# define FPUTS fputs +# define STRCMP strcmp +# define STRLEN strlen +#endif + +#define S(s) S1 (s) +#define S1(s) #s diff --git a/libio/tst-memstream4.c b/libio/tst-memstream4.c new file mode 100644 index 0000000..a83a8bf --- /dev/null +++ b/libio/tst-memstream4.c @@ -0,0 +1,64 @@ +/* Test for open_memstream BZ #21037. + Copyright (C) 2018 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 "tst-memstream.h" + +static void +mcheck_abort (enum mcheck_status ev) +{ + printf ("mecheck failed with status %d\n", (int) ev); + exit (1); +} + +static int +do_test (void) +{ + mcheck_pedantic (mcheck_abort); + + /* Check if freopen proper fflush the stream. */ + { + CHAR_T old[] = W("old"); + CHAR_T *buf = old; + size_t size; + + FILE *fp = OPEN_MEMSTREAM (&buf, &size); + TEST_VERIFY_EXIT (fp != NULL); + + FPUTS (W("new"), fp); + /* The stream buffer pointer should be updated with only a fflush or + fclose. */ + TEST_COMPARE (STRCMP (buf, old), 0); + + /* The old stream should be fflush the stream, even for an invalid + streams. */ + FILE *nfp = freopen ("invalid-file", "r", fp); + TEST_VERIFY_EXIT (nfp == NULL); + + TEST_VERIFY (STRCMP (buf, W("new")) == 0); + TEST_COMPARE_BLOB (buf, STRLEN (buf) * sizeof (CHAR_T), + W("new"), STRLEN (W("new")) * sizeof (CHAR_T)); + + TEST_COMPARE (fclose (fp), 0); + + free (buf); + } + + return 0; +} + +#include diff --git a/libio/tst-wmemstream4.c b/libio/tst-wmemstream4.c new file mode 100644 index 0000000..8ff146e --- /dev/null +++ b/libio/tst-wmemstream4.c @@ -0,0 +1,20 @@ +/* Test for open_wmemstream BZ #21037. + Copyright (C) 2018 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 + . */ + +#define TEST_WCHAR +#include -- cgit v1.1