libio: Multiple fixes for open_{w}memstram (BZ#18241 and BZ#20181)

This patches fixes multiples issues on open_{w}memstream reported on both
BZ#18241 and BZ#20181:

  - failed fseek does not set errno.
  - negative offset in fseek fails even when resulting position is
    a valid one.
  - a flush after write if the current write position is not at the
    end of the stream currupt data.

The main fix is on seek operation for memstream (_IO_{w}str_seekoff), where
both _IO_read_ptr and _IO_read_end pointer are updated if a write operation
has occured (similar to default file operations).  Also, to calculate the
offset on both read and write pointers, a temporary value is instead of
updating the argument supplied value.  Negative offset are valid if resulting
internal pointer is within the range of _IO_{read,write}_base and
_IO_{read,write}_end.

Also POSIX states that a null or wide null shall be appended to the current
buffer iff a write moves the position to a value larger than the current
lenght.  Current implementation appends a null or wide null regardless
of this condition.  This patch fixes it by removing the 'else' condition
on _IO_{w}mem_sync.

Checked on x86_64.

	[BZ #18241]
	[BZ #20181]
	* libio/Makefile (test): Add tst-memstream3 and tst-wmemstream3.
	* libio/memstream.c (_IO_mem_sync): Only append a null byte if
	write position is at the end the buffer.
	* libio/wmemstream.c (_IO_wmem_sync): Likewise.
	* libio/strops.c (_IO_str_switch_to_get_mode): New function.
	(_IO_str_seekoff): Set correct offset from negative displacement and
	set EINVAL for invalid ones.
	* libio/wstrops.c (enlarge_userbuf): Use correct function to calculate
	buffer length.
	(_IO_wstr_switch_to_get_mode): New function.
	(_IO_wstr_seekoff): Set correct offset from negative displacement and
	set EINVAL for invalid ones.
	* libio/tst-memstream3.c: New file.
	* libio/tst-wmemstream3.c: Likewise.
	* manual/examples/memstrm.c: Remove warning when priting size_t.
This commit is contained in:
Adhemerval Zanella 2016-07-25 14:54:29 -03:00 committed by Adhemerval Zanella
parent f280fa6d17
commit 645f97ced4
9 changed files with 348 additions and 63 deletions

View File

@ -1,3 +1,23 @@
2016-09-30 Adhemerval Zanella <adhemerval.zanella@linaro.org>
[BZ #18241]
[BZ #20181]
* libio/Makefile (test): Add tst-memstream3 and tst-wmemstream3.
* libio/memstream.c (_IO_mem_sync): Only append a null byte if
write position is at the end the buffer.
* libio/wmemstream.c (_IO_wmem_sync): Likewise.
* libio/strops.c (_IO_str_switch_to_get_mode): New function.
(_IO_str_seekoff): Set correct offset from negative displacement and
set EINVAL for invalid ones.
* libio/wstrops.c (enlarge_userbuf): Use correct function to calculate
buffer length.
(_IO_wstr_switch_to_get_mode): New function.
(_IO_wstr_seekoff): Set correct offset from negative displacement and
set EINVAL for invalid ones.
* libio/tst-memstream3.c: New file.
* libio/tst-wmemstream3.c: Likewise.
* manual/examples/memstrm.c: Remove warning when priting size_t.
2016-09-30 Joseph Myers <joseph@codesourcery.com>
* sysdeps/ieee754/dbl-64/dla.h [__FP_FAST_FMA] (DLA_FMS): Define

View File

@ -56,8 +56,8 @@ 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-wmemstream1 tst-wmemstream2 \
tst-memstream1 tst-memstream2 tst-memstream3 \
tst-wmemstream1 tst-wmemstream2 tst-wmemstream3 \
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 \

View File

@ -112,8 +112,6 @@ _IO_mem_sync (_IO_FILE *fp)
_IO_str_overflow (fp, '\0');
--fp->_IO_write_ptr;
}
else
*fp->_IO_write_ptr = '\0';
*mp->bufloc = fp->_IO_write_base;
*mp->sizeloc = fp->_IO_write_ptr - fp->_IO_write_base;

View File

@ -230,6 +230,21 @@ enlarge_userbuf (_IO_FILE *fp, _IO_off64_t offset, int reading)
return 0;
}
static void
_IO_str_switch_to_get_mode (_IO_FILE *fp)
{
if (_IO_in_backup (fp))
fp->_IO_read_base = fp->_IO_backup_base;
else
{
fp->_IO_read_base = fp->_IO_buf_base;
if (fp->_IO_write_ptr > fp->_IO_read_end)
fp->_IO_read_end = fp->_IO_write_ptr;
}
fp->_IO_read_ptr = fp->_IO_read_end = fp->_IO_write_ptr;
fp->_flags &= ~_IO_CURRENTLY_PUTTING;
}
_IO_off64_t
_IO_str_seekoff (_IO_FILE *fp, _IO_off64_t offset, int dir, int mode)
@ -239,14 +254,14 @@ _IO_str_seekoff (_IO_FILE *fp, _IO_off64_t offset, int dir, int mode)
if (mode == 0 && (fp->_flags & _IO_TIED_PUT_GET))
mode = (fp->_flags & _IO_CURRENTLY_PUTTING ? _IOS_OUTPUT : _IOS_INPUT);
bool was_writing = (fp->_IO_write_ptr > fp->_IO_write_base
|| _IO_in_put_mode (fp));
if (was_writing)
_IO_str_switch_to_get_mode (fp);
if (mode == 0)
{
/* Don't move any pointers. But there is no clear indication what
mode FP is in. Let's guess. */
if (fp->_IO_file_flags & _IO_NO_WRITES)
new_pos = fp->_IO_read_ptr - fp->_IO_read_base;
else
new_pos = fp->_IO_write_ptr - fp->_IO_write_base;
new_pos = fp->_IO_read_ptr - fp->_IO_read_base;
}
else
{
@ -256,48 +271,62 @@ _IO_str_seekoff (_IO_FILE *fp, _IO_off64_t offset, int dir, int mode)
/* Move the get pointer, if requested. */
if (mode & _IOS_INPUT)
{
_IO_ssize_t base;
switch (dir)
{
case _IO_seek_end:
offset += cur_size;
case _IO_seek_set:
base = 0;
break;
case _IO_seek_cur:
offset += fp->_IO_read_ptr - fp->_IO_read_base;
base = fp->_IO_read_ptr - fp->_IO_read_base;
break;
default: /* case _IO_seek_set: */
default: /* case _IO_seek_end: */
base = cur_size;
break;
}
if (offset < 0)
_IO_ssize_t maxval = SSIZE_MAX - base;
if (offset < -base || offset > maxval)
{
__set_errno (EINVAL);
return EOF;
}
base += offset;
if (base > cur_size
&& enlarge_userbuf (fp, base, 1) != 0)
return EOF;
if ((_IO_ssize_t) offset > cur_size
&& enlarge_userbuf (fp, offset, 1) != 0)
return EOF;
fp->_IO_read_ptr = fp->_IO_read_base + offset;
fp->_IO_read_ptr = fp->_IO_read_base + base;
fp->_IO_read_end = fp->_IO_read_base + cur_size;
new_pos = offset;
new_pos = base;
}
/* Move the put pointer, if requested. */
if (mode & _IOS_OUTPUT)
{
_IO_ssize_t base;
switch (dir)
{
case _IO_seek_end:
offset += cur_size;
case _IO_seek_set:
base = 0;
break;
case _IO_seek_cur:
offset += fp->_IO_write_ptr - fp->_IO_write_base;
base = fp->_IO_write_ptr - fp->_IO_write_base;
break;
default: /* case _IO_seek_set: */
default: /* case _IO_seek_end: */
base = cur_size;
break;
}
if (offset < 0)
_IO_ssize_t maxval = SSIZE_MAX - base;
if (offset < -base || offset > maxval)
{
__set_errno (EINVAL);
return EOF;
}
base += offset;
if (base > cur_size
&& enlarge_userbuf (fp, base, 0) != 0)
return EOF;
if ((_IO_ssize_t) offset > cur_size
&& enlarge_userbuf (fp, offset, 0) != 0)
return EOF;
fp->_IO_write_ptr = fp->_IO_write_base + offset;
new_pos = offset;
fp->_IO_write_ptr = fp->_IO_write_base + base;
new_pos = base;
}
}
return new_pos;

165
libio/tst-memstream3.c Normal file
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@ -0,0 +1,165 @@
/* Test for open_memstream implementation.
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
<http://www.gnu.org/licenses/>. */
#include <mcheck.h>
#include <stdio.h>
#include <stdarg.h>
#include <errno.h>
#ifndef CHAR_T
# define CHAR_T char
# define W(o) o
# define OPEN_MEMSTREAM open_memstream
# define PRINTF printf
# define FWRITE fwrite
# define FPUTC fputc
# define STRCMP strcmp
#endif
#define S(s) S1 (s)
#define S1(s) #s
static void
mcheck_abort (enum mcheck_status ev)
{
printf ("mecheck failed with status %d\n", (int) ev);
exit (1);
}
static void
error_printf (int line, const char *fmt, ...)
{
va_list ap;
printf ("error: %s:%i: ", __FILE__, line);
va_start (ap, fmt);
vprintf (fmt, ap);
va_end (ap);
}
#define ERROR_RET1(...) \
{ error_printf(__LINE__, __VA_ARGS__); return 1; }
static int
do_test_bz18241 (void)
{
CHAR_T *buf;
size_t size;
FILE *fp = OPEN_MEMSTREAM (&buf, &size);
if (fp == NULL)
ERROR_RET1 ("%s failed\n", S(OPEN_MEMSTREAM));
if (FPUTC (W('a'), fp) != W('a'))
ERROR_RET1 ("%s failed (errno = %d)\n", S(FPUTC), errno);
if (fflush (fp) != 0)
ERROR_RET1 ("fflush failed (errno = %d)\n", errno);
if (fseek (fp, -2, SEEK_SET) != -1)
ERROR_RET1 ("fseek failed (errno = %d)\n", errno);
if (errno != EINVAL)
ERROR_RET1 ("errno != EINVAL\n");
if (ftell (fp) != 1)
ERROR_RET1 ("ftell failed (errno = %d)\n", errno);
if (ferror (fp) != 0)
ERROR_RET1 ("ferror != 0\n");
if (fseek (fp, -1, SEEK_CUR) == -1)
ERROR_RET1 ("fseek failed (errno = %d)\n", errno);
if (ftell (fp) != 0)
ERROR_RET1 ("ftell failed (errno = %d)\n", errno);
if (ferror (fp) != 0)
ERROR_RET1 ("ferror != 0\n");
if (FPUTC (W('b'), fp) != W('b'))
ERROR_RET1 ("%s failed (errno = %d)\n", S(FPUTC), errno);
if (fflush (fp) != 0)
ERROR_RET1 ("fflush failed (errno = %d)\n", errno);
if (fclose (fp) != 0)
ERROR_RET1 ("fclose failed (errno = %d\n", errno);
if (STRCMP (buf, W("b")) != 0)
ERROR_RET1 ("%s failed\n", S(STRCMP));
free (buf);
return 0;
}
static int
do_test_bz20181 (void)
{
CHAR_T *buf;
size_t size;
size_t ret;
FILE *fp = OPEN_MEMSTREAM (&buf, &size);
if (fp == NULL)
ERROR_RET1 ("%s failed\n", S(OPEN_MEMSTREAM));
if ((ret = FWRITE (W("abc"), 1, 3, fp)) != 3)
ERROR_RET1 ("%s failed (errno = %d)\n", S(FWRITE), errno);
if (fseek (fp, 0, SEEK_SET) != 0)
ERROR_RET1 ("fseek failed (errno = %d)\n", errno);
if (FWRITE (W("z"), 1, 1, fp) != 1)
ERROR_RET1 ("%s failed (errno = %d)\n", S(FWRITE), errno);
if (fflush (fp) != 0)
ERROR_RET1 ("fflush failed (errno = %d)\n", errno);
/* Avoid truncating the buffer on close. */
if (fseek (fp, 3, SEEK_SET) != 0)
ERROR_RET1 ("fseek failed (errno = %d)\n", errno);
if (fclose (fp) != 0)
ERROR_RET1 ("fclose failed (errno = %d\n", errno);
if (size != 3)
ERROR_RET1 ("size != 3\n");
if (buf[0] != W('z')
|| buf[1] != W('b')
|| buf[2] != W('c'))
{
PRINTF (W("error: buf {%c,%c,%c} != {z,b,c}\n"),
buf[0], buf[1], buf[2]);
return 1;
}
free (buf);
return 0;
}
static int
do_test (void)
{
int ret = 0;
mcheck_pedantic (mcheck_abort);
ret += do_test_bz18241 ();
ret += do_test_bz20181 ();
return ret;
}
#define TEST_FUNCTION do_test ()
#include "../test-skeleton.c"

44
libio/tst-wmemstream3.c Normal file
View File

@ -0,0 +1,44 @@
/* Test for open_memstream implementation.
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
<http://www.gnu.org/licenses/>. */
#include <wchar.h>
/* Straighforward implementation so tst-memstream3 could use check
fwrite on open_memstream. */
static size_t
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 STRCMP wcscmp
#include "tst-memstream3.c"

View File

@ -112,8 +112,6 @@ _IO_wmem_sync (_IO_FILE *fp)
_IO_wstr_overflow (fp, '\0');
--fp->_wide_data->_IO_write_ptr;
}
else
*fp->_wide_data->_IO_write_ptr = '\0';
*mp->bufloc = fp->_wide_data->_IO_write_base;
*mp->sizeloc = (fp->_wide_data->_IO_write_ptr

View File

@ -169,7 +169,7 @@ _IO_wstr_count (_IO_FILE *fp)
static int
enlarge_userbuf (_IO_FILE *fp, _IO_off64_t offset, int reading)
{
if ((_IO_ssize_t) offset <= _IO_blen (fp))
if ((_IO_ssize_t) offset <= _IO_wblen (fp))
return 0;
struct _IO_wide_data *wd = fp->_wide_data;
@ -235,6 +235,22 @@ enlarge_userbuf (_IO_FILE *fp, _IO_off64_t offset, int reading)
return 0;
}
static void
_IO_wstr_switch_to_get_mode (_IO_FILE *fp)
{
if (_IO_in_backup (fp))
fp->_wide_data->_IO_read_base = fp->_wide_data->_IO_backup_base;
else
{
fp->_wide_data->_IO_read_base = fp->_wide_data->_IO_buf_base;
if (fp->_wide_data->_IO_write_ptr > fp->_wide_data->_IO_read_end)
fp->_wide_data->_IO_read_end = fp->_wide_data->_IO_write_ptr;
}
fp->_wide_data->_IO_read_ptr = fp->_wide_data->_IO_write_ptr;
fp->_wide_data->_IO_read_end = fp->_wide_data->_IO_write_ptr;
fp->_flags &= ~_IO_CURRENTLY_PUTTING;
}
_IO_off64_t
_IO_wstr_seekoff (_IO_FILE *fp, _IO_off64_t offset, int dir, int mode)
@ -244,15 +260,16 @@ _IO_wstr_seekoff (_IO_FILE *fp, _IO_off64_t offset, int dir, int mode)
if (mode == 0 && (fp->_flags & _IO_TIED_PUT_GET))
mode = (fp->_flags & _IO_CURRENTLY_PUTTING ? _IOS_OUTPUT : _IOS_INPUT);
bool was_writing = (fp->_wide_data->_IO_write_ptr >
fp->_wide_data->_IO_write_base
|| _IO_in_put_mode (fp));
if (was_writing)
_IO_wstr_switch_to_get_mode (fp);
if (mode == 0)
{
/* Don't move any pointers. But there is no clear indication what
mode FP is in. Let's guess. */
if (fp->_IO_file_flags & _IO_NO_WRITES)
new_pos = fp->_wide_data->_IO_read_ptr - fp->_wide_data->_IO_read_base;
else
new_pos = (fp->_wide_data->_IO_write_ptr
- fp->_wide_data->_IO_write_base);
new_pos = (fp->_wide_data->_IO_write_ptr
- fp->_wide_data->_IO_write_base);
}
else
{
@ -262,25 +279,32 @@ _IO_wstr_seekoff (_IO_FILE *fp, _IO_off64_t offset, int dir, int mode)
/* Move the get pointer, if requested. */
if (mode & _IOS_INPUT)
{
_IO_ssize_t base;
switch (dir)
{
case _IO_seek_end:
offset += cur_size;
case _IO_seek_set:
base = 0;
break;
case _IO_seek_cur:
offset += (fp->_wide_data->_IO_read_ptr
- fp->_wide_data->_IO_read_base);
base = (fp->_wide_data->_IO_read_ptr
- fp->_wide_data->_IO_read_base);
break;
default: /* case _IO_seek_set: */
default: /* case _IO_seek_end: */
base = cur_size;
break;
}
if (offset < 0)
return EOF;
if ((_IO_ssize_t) offset > cur_size
&& enlarge_userbuf (fp, offset, 1) != 0)
_IO_ssize_t maxval = SSIZE_MAX/sizeof (wchar_t) - base;
if (offset < -base || offset > maxval)
{
__set_errno (EINVAL);
return EOF;
}
base += offset;
if (base > cur_size
&& enlarge_userbuf (fp, base, 1) != 0)
return EOF;
fp->_wide_data->_IO_read_ptr = (fp->_wide_data->_IO_read_base
+ offset);
+ base);
fp->_wide_data->_IO_read_end = (fp->_wide_data->_IO_read_base
+ cur_size);
new_pos = offset;
@ -289,26 +313,33 @@ _IO_wstr_seekoff (_IO_FILE *fp, _IO_off64_t offset, int dir, int mode)
/* Move the put pointer, if requested. */
if (mode & _IOS_OUTPUT)
{
_IO_ssize_t base;
switch (dir)
{
case _IO_seek_end:
offset += cur_size;
case _IO_seek_set:
base = 0;
break;
case _IO_seek_cur:
offset += (fp->_wide_data->_IO_write_ptr
- fp->_wide_data->_IO_write_base);
base = (fp->_wide_data->_IO_write_ptr
- fp->_wide_data->_IO_write_base);
break;
default: /* case _IO_seek_set: */
default: /* case _IO_seek_end: */
base = cur_size;
break;
}
if (offset < 0)
return EOF;
if ((_IO_ssize_t) offset > cur_size
&& enlarge_userbuf (fp, offset, 0) != 0)
_IO_ssize_t maxval = SSIZE_MAX/sizeof (wchar_t) - base;
if (offset < -base || offset > maxval)
{
__set_errno (EINVAL);
return EOF;
}
base += offset;
if (base > cur_size
&& enlarge_userbuf (fp, base, 0) != 0)
return EOF;
fp->_wide_data->_IO_write_ptr = (fp->_wide_data->_IO_write_base
+ offset);
new_pos = offset;
+ base);
new_pos = base;
}
}
return new_pos;

View File

@ -27,10 +27,10 @@ main (void)
stream = open_memstream (&bp, &size);
fprintf (stream, "hello");
fflush (stream);
printf ("buf = `%s', size = %d\n", bp, size);
printf ("buf = `%s', size = %zu\n", bp, size);
fprintf (stream, ", world");
fclose (stream);
printf ("buf = `%s', size = %d\n", bp, size);
printf ("buf = `%s', size = %zu\n", bp, size);
return 0;
}