Movatterモバイル変換

This is the mail archive of thelibc-alpha@sourceware.orgmailing list for theglibc project.
Index Nav:	[Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav:	[Date Prev] [Date Next]	[Thread Prev] [Thread Next]
Other format:	[Raw text]
Re: [PATCH] libio: Flush stream at freopen (BZ#21037)

From: Adhemerval Zanella <adhemerval dot zanella at linaro dot org>
To: libc-alpha at sourceware dot org
Date: Tue, 8 Aug 2017 10:52:49 -0300
Subject: Re: [PATCH] libio: Flush stream at freopen (BZ#21037)
Authentication-results: sourceware.org; auth=none
References: <1499977587-28794-1-git-send-email-adhemerval.zanella@linaro.org>
Ping.On 13/07/2017 17:26, Adhemerval Zanella wrote:> 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.> > From Florian's comment, this is intended for 2.27.  This patch should> be applied on top on 'libio: Fix open_memstream fflush (NULL) (BZ#21735)' [2].> > [BZ #21037]> * libio/freopen.c (freopen): Sync stream before reopen and adjust to> new fd_to_filename interface.> * libio/freopen64.c (freopen64): 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.> * libio/Makefile (tests): Add tst-memstream5 and tst-wmemstream5.> * libio/tst-memstream.h (FPUTS): New macro.> * libio/tst-memstream4.c: New file.> * libio/tst-wmemstream4.c: Likewise.> > [1]http://pubs.opengroup.org/onlinepubs/9699919799/> [2]https://sourceware.org/ml/libc-alpha/2017-07/msg00548.html> --->  ChangeLog                                | 14 ++++++++>  libio/Makefile                           |  3 +->  libio/freopen.c                          | 33 ++++++++++------->  libio/freopen64.c                        | 30 ++++++++++------>  libio/tst-memstream.h                    |  2 ++>  libio/tst-memstream5.c                   | 62 ++++++++++++++++++++++++++++++++>  libio/tst-wmemstream5.c                  | 20 +++++++++++>  sysdeps/generic/fd_to_filename.h         |  6 ++-->  sysdeps/unix/sysv/linux/fd_to_filename.h | 31 +++++----------->  9 files changed, 151 insertions(+), 50 deletions(-)>  create mode 100644 libio/tst-memstream5.c>  create mode 100644 libio/tst-wmemstream5.c> > diff --git a/libio/Makefile b/libio/Makefile> index 6ee809a..8adf2d8 100644> --- a/libio/Makefile> +++ b/libio/Makefile> @@ -58,8 +58,9 @@ tests = tst_swprintf tst_wprintf tst_swscanf tst_wscanf tst_getwc tst_putwc   \>  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-memstream4 \> +tst-memstream5 \>  tst-wmemstream1 tst-wmemstream2 tst-wmemstream3 tst-wmemstream4 \> -bug-memstream1 bug-wmemstream1 \> +tst-wmemstream5 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 \>  tst-ftell-append tst-fputws> diff --git a/libio/freopen.c b/libio/freopen.c> index 980523a..505e77d 100644> --- a/libio/freopen.c> +++ b/libio/freopen.c> @@ -24,28 +24,38 @@>     This exception applies to code released by its copyright holders>     in files containing the exception.  */>  > -#include "libioP.h"> -#include "stdio.h"> +#include <stdio.h>>  #include <fcntl.h>>  #include <stdlib.h>>  #include <unistd.h>>  > -#include <shlib-compat.h>> +#include <libioP.h>>  #include <fd_to_filename.h>> -> -#include <kernel-features.h>> +#include <shlib-compat.h>>  >  FILE *>  freopen (const char *filename, const char *mode, FILE *fp)>  {> -  FILE *result;> +  FILE *result = NULL;> +  char fdfilename[30];> +>    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;> +  if (filename == NULL && fd >= 0)> +    gfilename = fd_to_filename (fd, fdfilename, sizeof fdfilename)> +? fdfilename : NULL;> +  else> +    gfilename = filename;> +>    fp->_flags2 |= _IO_FLAGS2_NOCLOSE;>  #if SHLIB_COMPAT (libc, GLIBC_2_0, GLIBC_2_1)>    if (&_IO_stdin_used == NULL)> @@ -101,9 +111,6 @@ 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 1e56de6..28203c9 100644> --- a/libio/freopen64.c> +++ b/libio/freopen64.c> @@ -24,27 +24,37 @@>     This exception applies to code released by its copyright holders>     in files containing the exception.  */>  > -#include "libioP.h"> -#include "stdio.h"> +#include <stdio.h>>  #include <fcntl.h>>  #include <stdlib.h>>  #include <unistd.h>>  > +#include <libioP.h>>  #include <fd_to_filename.h>>  > -#include <kernel-features.h>> ->  FILE *>  freopen64 (const char *filename, const char *mode, FILE *fp)>  {> -  FILE *result;> +  FILE *result = NULL;> +  char fdfilename[30];> +>    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;> +  if (filename == NULL && fd >= 0)> +    gfilename = fd_to_filename (fd, fdfilename, sizeof fdfilename)> +? fdfilename : NULL;> +  else> +    gfilename = filename;> +>    fp->_flags2 |= _IO_FLAGS2_NOCLOSE;>    _IO_file_close_it (fp);>    _IO_JUMPS_FILE_plus (fp) = &_IO_file_jumps;> @@ -84,8 +94,6 @@ 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> index ffc2a65..86ea0d7 100644> --- a/libio/tst-memstream.h> +++ b/libio/tst-memstream.h> @@ -49,6 +49,7 @@ fwwrite (const void *ptr, size_t size, size_t nmemb, FILE *arq)>  # define PRINTF wprintf>  # define FWRITE fwwrite>  # define FPUTC  fputwc> +# define FPUTS  fputws>  # define STRCMP wcscmp>  # define STRLEN wcslen>  #else> @@ -58,6 +59,7 @@ fwwrite (const void *ptr, size_t size, size_t nmemb, FILE *arq)>  # define PRINTF printf>  # define FWRITE fwrite>  # define FPUTC fputc> +# define FPUTS  fputs>  # define STRCMP strcmp>  # define STRLEN strlen>  #endif> diff --git a/libio/tst-memstream5.c b/libio/tst-memstream5.c> new file mode 100644> index 0000000..7c1f37c> --- /dev/null> +++ b/libio/tst-memstream5.c> @@ -0,0 +1,62 @@> +/* Test for open_memstream BZ #21037.> +   Copyright (C) 2017 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> +   <http://www.gnu.org/licenses/>.  */> +> +#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_VERIFY (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 (nfp == NULL);> +> +    TEST_VERIFY (STRCMP (buf, W("new")) == 0);> +> +    TEST_VERIFY (fclose (fp) == 0);> +> +    free (buf);> +  }> +> +  return 0;> +}> +> +#include <support/test-driver.c>> diff --git a/libio/tst-wmemstream5.c b/libio/tst-wmemstream5.c> new file mode 100644> index 0000000..4e87289> --- /dev/null> +++ b/libio/tst-wmemstream5.c> @@ -0,0 +1,20 @@> +/* Test for open_wmemstream BZ #21037.> +   Copyright (C) 2017 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> +   <http://www.gnu.org/licenses/>.  */> +> +#define TEST_WCHAR> +#include <libio/tst-memstream5.c>> diff --git a/sysdeps/generic/fd_to_filename.h b/sysdeps/generic/fd_to_filename.h> index fe15f5d..db594f2 100644> --- a/sysdeps/generic/fd_to_filename.h> +++ b/sysdeps/generic/fd_to_filename.h> @@ -18,8 +18,8 @@>  >  /* In general there is no generic way to query filename for an open>     file descriptor.  */> -static inline const char *> -fd_to_filename (int fd)> +static inline bool> +fd_to_filename (int fd, char *buf, size_t len)>  {> -  return NULL;> +  return false;>  }> diff --git a/sysdeps/unix/sysv/linux/fd_to_filename.h b/sysdeps/unix/sysv/linux/fd_to_filename.h> index 414a30f..6cd0bdd 100644> --- a/sysdeps/unix/sysv/linux/fd_to_filename.h> +++ b/sysdeps/unix/sysv/linux/fd_to_filename.h> @@ -16,30 +16,17 @@>     License along with the GNU C Library; if not, see>     <http://www.gnu.org/licenses/>.  */>  > -#include <stdlib.h>> -#include <string.h>> +#include <stdio.h>>  #include <sys/stat.h>> -#include <_itoa.h>>  > -static inline const char *> -fd_to_filename (int fd)> +static inline bool> +fd_to_filename (int fd, char *buf, size_t len)>  {> -  char *ret = malloc (30);> +  __snprintf (buf, len, "/proc/self/fd/%d", fd);>  > -  if (ret != NULL)> -    {> -      struct stat64 st;> -> -      *_fitoa_word (fd, __stpcpy (ret, "/proc/self/fd/"), 10, 0) = '\0';> -> -      /* We must make sure the file exists.  */> -      if (__lxstat64 (_STAT_VER, ret, &st) < 0)> -{> -  /* /proc is not mounted or something else happened.  Don't> -     return the file name.  */> -  free (ret);> -  ret = NULL;> -}> -    }> -  return ret;> +  /* We must make sure the file exists.  */> +  if (__lxstat64 (_STAT_VER, buf, & (struct stat64) {}) < 0)> +    /* /proc is not mounted or something else happened.  */> +    return false;> +  return true;>  }>
Index Nav:	[Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav:	[Date Prev] [Date Next]	[Thread Prev] [Thread Next]
[8]ページ先頭