* [PATCH v2] libio: Flush stream at freopen (BZ#21037)
@ 2018-06-13 21:33 Adhemerval Zanella
2018-06-14 13:20 ` Andreas Schwab
0 siblings, 1 reply; 5+ messages in thread
From: Adhemerval Zanella @ 2018-06-13 21:33 UTC (permalink / raw)
To: libc-alpha
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/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/
---
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 077bd40..5b2308e 100644
--- a/libio/Makefile
+++ b/libio/Makefile
@@ -60,8 +60,9 @@ 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 tst-bz22415 tst-fgetc-after-eof
diff --git a/libio/freopen.c b/libio/freopen.c
index abf19e9..fa63429 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 ea7ebd3..1daeba6 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 bacfe5b..c60be86 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 297716b..8381f6d 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;
}
--
2.7.4
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH v2] libio: Flush stream at freopen (BZ#21037)
2018-06-13 21:33 [PATCH v2] libio: Flush stream at freopen (BZ#21037) Adhemerval Zanella
@ 2018-06-14 13:20 ` Andreas Schwab
2018-06-14 15:02 ` Adhemerval Zanella
0 siblings, 1 reply; 5+ messages in thread
From: Andreas Schwab @ 2018-06-14 13:20 UTC (permalink / raw)
To: Adhemerval Zanella; +Cc: libc-alpha
On Jun 13 2018, Adhemerval Zanella <adhemerval.zanella@linaro.org> wrote:
> * libio/tst-memstream.h (FPUTS): New macro.
That file doesn't exist yet. Where does it come from?
Andreas.
--
Andreas Schwab, SUSE Labs, schwab@suse.de
GPG Key fingerprint = 0196 BAD8 1CE9 1970 F4BE 1748 E4D4 88E3 0EEA B9D7
"And now for something completely different."
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH v2] libio: Flush stream at freopen (BZ#21037)
2018-06-14 13:20 ` Andreas Schwab
@ 2018-06-14 15:02 ` Adhemerval Zanella
2018-06-14 16:43 ` Paul Eggert
0 siblings, 1 reply; 5+ messages in thread
From: Adhemerval Zanella @ 2018-06-14 15:02 UTC (permalink / raw)
To: Andreas Schwab; +Cc: libc-alpha
On 14/06/2018 10:20, Andreas Schwab wrote:
> On Jun 13 2018, Adhemerval Zanella <adhemerval.zanella@linaro.org> wrote:
>
>> * libio/tst-memstream.h (FPUTS): New macro.
>
> That file doesn't exist yet. Where does it come from?
>
> Andreas.
>
Bacause I rebased against a wrong branch. Below it is an updated patch
(which I fixed some copyright dates as well).
---
* 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.
---
diff --git a/libio/Makefile b/libio/Makefile
index cbe14a8..077bd40 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..fa63429 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 ea7ebd3..1daeba6 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
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
+ <http://www.gnu.org/licenses/>. */
+
+#include <mcheck.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <stdarg.h>
+#include <errno.h>
+
+#include <support/check.h>
+
+#ifdef TEST_WCHAR
+# include <wchar.h>
+
+/* 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..43082f1
--- /dev/null
+++ b/libio/tst-memstream4.c
@@ -0,0 +1,62 @@
+/* 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
+ <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-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
+ <http://www.gnu.org/licenses/>. */
+
+#define TEST_WCHAR
+#include <libio/tst-memstream4.c>
diff --git a/sysdeps/generic/fd_to_filename.h b/sysdeps/generic/fd_to_filename.h
index bacfe5b..c60be86 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 297716b..8381f6d 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;
}
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH v2] libio: Flush stream at freopen (BZ#21037)
2018-06-14 15:02 ` Adhemerval Zanella
@ 2018-06-14 16:43 ` Paul Eggert
2018-06-14 18:28 ` Adhemerval Zanella
0 siblings, 1 reply; 5+ messages in thread
From: Paul Eggert @ 2018-06-14 16:43 UTC (permalink / raw)
To: Adhemerval Zanella, Andreas Schwab; +Cc: libc-alpha
On 06/14/2018 08:01 AM, Adhemerval Zanella wrote:
> + char fdfilename[30];
The magic number 30 should be turned into a named constant defined in
fd_to_filename.h, to help prevent future mistakes. Once that is done,
you can change the signature of fd_to_filename to not pass the size, and
to require the caller to pass an array of at least size 30, so that
fd_to_filename need not check for buffer overflow (see below for more on
this).
> + const char *gfilename;
> + if (filename == NULL && fd >= 0)
> + gfilename = fd_to_filename (fd, fdfilename, sizeof fdfilename)
> + ? fdfilename : NULL;
> + else
> + gfilename = filename;
Cleaner would be:
const char *gfilename
= filename != NULL ? filename : fd_to_filename (fd, fdfilename);
That is, let fd_to_filename worry about what to do with negative fd, and
have it return fdfilename or NULL, and don't pass the size (which should
be that magic number regardless).
> -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;
> }
The __snprintf would be quite wrong if the string did not fit. Again, I
suggest simply requiring the buffer to be long enough and not checking
its length, and sticking with stpcpy + _fitoa_word which should be more
efficient than __snprintf anyway (or if you prefer simplicity to speed,
just use sprintf).
The '& (struct stat64) {}' construct looks pretty but is less efficient
as it makes the compiler zero out the structure unnecessarily, so the
code should keep doing that struct the old-fashioned way.
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH v2] libio: Flush stream at freopen (BZ#21037)
2018-06-14 16:43 ` Paul Eggert
@ 2018-06-14 18:28 ` Adhemerval Zanella
0 siblings, 0 replies; 5+ messages in thread
From: Adhemerval Zanella @ 2018-06-14 18:28 UTC (permalink / raw)
To: Paul Eggert, Andreas Schwab; +Cc: libc-alpha
On 14/06/2018 13:43, Paul Eggert wrote:
> On 06/14/2018 08:01 AM, Adhemerval Zanella wrote:
>> + char fdfilename[30];
>
> The magic number 30 should be turned into a named constant defined in fd_to_filename.h, to help prevent future mistakes. Once that is done, you can change the signature of fd_to_filename to not pass the size, and to require the caller to pass an array of at least size 30, so that fd_to_filename need not check for buffer overflow (see below for more on this).
>
>> +Â const char *gfilename;
>> +Â if (filename == NULL && fd >= 0)
>> +Â Â Â gfilename = fd_to_filename (fd, fdfilename, sizeof fdfilename)
>> +Â Â Â Â Â Â Â ? fdfilename : NULL;
>> +Â else
>> +Â Â Â gfilename = filename;
>
> Cleaner would be:
>
> Â const char *gfilename
> Â Â Â = filename != NULL ? filename : fd_to_filename (fd, fdfilename);
>
> That is, let fd_to_filename worry about what to do with negative fd, and have it return fdfilename or NULL, and don't pass the size (which should be that magic number regardless).
>
>
>> -static inline const char *
>> -fd_to_filename (int fd)
>> +static inline bool
>> +fd_to_filename (int fd, char *buf, size_t len)
>> Â {
>> -Â char *ret = malloc (30);
>> +Â __snprintf (buf, len, "/proc/self/fd/%d", fd);
>> Â -Â if (ret != NULL)
>> -Â Â Â {
>> -Â Â Â Â Â struct stat64 st;
>> -
>> -Â Â Â Â Â *_fitoa_word (fd, __stpcpy (ret, "/proc/self/fd/"), 10, 0) = '\0';
>> -
>> -     /* We must make sure the file exists. */
>> -Â Â Â Â Â if (__lxstat64 (_STAT_VER, ret, &st) < 0)
>> -Â Â Â {
>> -     /* /proc is not mounted or something else happened. Don't
>> -        return the file name. */
>> -Â Â Â Â Â free (ret);
>> -Â Â Â Â Â ret = NULL;
>> -Â Â Â }
>> -Â Â Â }
>> -Â return ret;
>> + /* We must make sure the file exists. */
>> +Â if (__lxstat64 (_STAT_VER, buf, & (struct stat64) {}) < 0)
>> +   /* /proc is not mounted or something else happened. */
>> +Â Â Â return false;
>> +Â return true;
>> Â }
>
> The __snprintf would be quite wrong if the string did not fit. Again, I suggest simply requiring the buffer to be long enough and not checking its length, and sticking with stpcpy + _fitoa_word which should be more efficient than __snprintf anyway (or if you prefer simplicity to speed, just use sprintf).
>
> The '& (struct stat64) {}' construct looks pretty but is less efficient as it makes the compiler zero out the structure unnecessarily, so the code should keep doing that struct the old-fashioned way.
Thanks, fixed based on your review:
---
[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.
---
diff --git a/libio/Makefile b/libio/Makefile
index cbe14a8..077bd40 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 <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[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..d13c70f 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 <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[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
+ <http://www.gnu.org/licenses/>. */
+
+#include <mcheck.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <stdarg.h>
+#include <errno.h>
+
+#include <support/check.h>
+
+#ifdef TEST_WCHAR
+# include <wchar.h>
+
+/* 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..43082f1
--- /dev/null
+++ b/libio/tst-memstream4.c
@@ -0,0 +1,62 @@
+/* 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
+ <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-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
+ <http://www.gnu.org/licenses/>. */
+
+#define TEST_WCHAR
+#include <libio/tst-memstream4.c>
diff --git a/sysdeps/generic/fd_to_filename.h b/sysdeps/generic/fd_to_filename.h
index bacfe5b..d41b345 100644
--- a/sysdeps/generic/fd_to_filename.h
+++ b/sysdeps/generic/fd_to_filename.h
@@ -16,10 +16,12 @@
License along with the GNU C Library; if not, see
<http://www.gnu.org/licenses/>. */
+#define FD_TO_FILENAME_SIZE 0
+
/* In general there is no generic way to query filename for an open
file descriptor. */
static inline const char *
-fd_to_filename (int fd)
+fd_to_filename (int fd, char *buf)
{
return NULL;
}
diff --git a/sysdeps/unix/sysv/linux/fd_to_filename.h b/sysdeps/unix/sysv/linux/fd_to_filename.h
index 297716b..ae88ce8 100644
--- a/sysdeps/unix/sysv/linux/fd_to_filename.h
+++ b/sysdeps/unix/sysv/linux/fd_to_filename.h
@@ -16,30 +16,21 @@
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>
+
+#define FD_TO_FILENAME_SIZE ((sizeof ("/proc/self/fd/") - 1) \
+ + (sizeof ("2147483647") - 1) + 1)
static inline const char *
-fd_to_filename (int fd)
+fd_to_filename (int fd, char *buf)
{
- char *ret = malloc (30);
-
- 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;
+ *_fitoa_word (fd, __stpcpy (buf, "/proc/self/fd/"), 10, 0) = '\0';
+
+ /* We must make sure the file exists. */
+ struct stat64 st;
+ if (__lxstat64 (_STAT_VER, buf, &st) < 0)
+ /* /proc is not mounted or something else happened. */
+ return NULL;
+ return buf;
}
^ permalink raw reply [flat|nested] 5+ messages in thread
end of thread, other threads:[~2018-06-14 18:28 UTC | newest]
Thread overview: 5+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2018-06-13 21:33 [PATCH v2] libio: Flush stream at freopen (BZ#21037) Adhemerval Zanella
2018-06-14 13:20 ` Andreas Schwab
2018-06-14 15:02 ` Adhemerval Zanella
2018-06-14 16:43 ` Paul Eggert
2018-06-14 18:28 ` Adhemerval Zanella
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