libio: fmemopen rewrite to POSIX compliance

This patch added a new fmemopen version, for glibc 2.22, that aims to be
POSIX complaint.  It fixes some long-stading glibc fmemopen issues, such
as:

* it changes the way fseek with SEEK_END works on fmemopen to seek
  relative to buffer size instead of first '\0'.  This is default mode and
  'b' opening mode does not change internal behavior (bz#6544).

* fix apending opening mode to use as start position either first null
  byte of len specified in function call (bz#13152 and #13151).

* remove binary option 'b' and internal different handling (bz#12836)

* fix seek/SEE_END with negative values (bz#14292).

A compatibility symbol is provided to with old behavior for older symbols
version (2.2.5).

	* include/stdio.h (fmemopen): Remove hidden prototype.
	(__fmemopen): Add new hidden prototype.
	* libio/Makefile: Add oldfmemopen object.
	* libio/Versions [GLIBC_2.22]: Add new fmemopen symbol.
	* libio/fmemopen.c (__fmemopen): Function rewrite to be POSIX
	compliance.
	* libio/oldfmemopen.c: New file: old fmemopen implementation for
	symbol compatibility.
	* stdio-common/Makefile [tests]: Add new tst-fmemopen3.
	* stdio-common/psiginfo.c [psiginfo]: Call __fmemopen instead of
	fmemopen.
	* stdio-common/tst-fmemopen3.c: New file: more fmemopen tests, focus
	on append and read mode.
	* sysdeps/unix/sysv/linux/aarch64/libc.abilist [GLIBC_2.22]: Add
	fmemopen.
	* sysdeps/unix/sysv/linux/alpha/libc.abilist [GLIBC_2.22]: Likewise.
	* sysdeps/unix/sysv/linux/arm/libc.abilist [GLIBC_2.22]: Likewise.
	* sysdeps/unix/sysv/linux/i386/libc.abilist [GLIBC_2.22]: Likewise.
	* sysdeps/unix/sysv/linux/ia64/libc.abilist [GLIBC_2.22]:
	Likewise.
	* sysdeps/unix/sysv/linux/m68k/coldfire/libc.abilist
	[GLIBC_2.22]: Likewise.
	* sysdeps/unix/sysv/linux/m68k/m680x0/libc.abilist [GLIBC_2.22]:
	Likewise.
	* sysdeps/unix/sysv/linux/microblaze/libc.abilist [GLIBC_2.22]:
	Likewise.
	* sysdeps/unix/sysv/linux/mips/mips32/fpu/libc.abilist
	[GLIBC_2.22]: Likewise.
	* sysdeps/unix/sysv/linux/mips/mips32/nofpu/libc.abilist
	[GLIBC_2.22]: Likewise.
	* sysdeps/unix/sysv/linux/mips/mips64/n32/libc.abilist
	[GLIBC_2.22]: Likewise.
	* sysdeps/unix/sysv/linux/mips/mips64/n64/libc.abilist
	[GLIBC_2.22]: Likewise.
	* sysdeps/unix/sysv/linux/powerpc/powerpc32/fpu/libc.abilist
	[GLIBC_2.22]: Likewise.
	* sysdeps/unix/sysv/linux/powerpc/powerpc32/nofpu/libc.abilist
	[GLIBC_2.22]: Likewise.
	* sysdeps/unix/sysv/linux/powerpc/powerpc64/libc.abilist
	[GLIBC_2.22]: Likewise.
	* sysdeps/unix/sysv/linux/s390/s390-32/libc.abilist [GLIBC_2.22]:
	Likewise.
	* sysdeps/unix/sysv/linux/s390/s390-64/libc.abilist [GLIBC_2.22]:
	Likewise.
	* sysdeps/unix/sysv/linux/sh/libc.abilist [GLIBC_2.22]: Likewise.
	* sysdeps/unix/sysv/linux/sparc/sparc32/libc.abilist
	[GLIBC_2.22]: Likewise.
	* sysdeps/unix/sysv/linux/sparc/sparc64/libc.abilist
	[GLIBC_2.22]: Likewise.
	* sysdeps/unix/sysv/linux/tile/tilegx/tilegx32/libc.abilist
	[GLIBC_2.22]: Likewise.
	* sysdeps/unix/sysv/linux/tile/tilegx/tilegx64/libc.abilist
	[GLIBC_2.22]: Likewise.
	* sysdeps/unix/sysv/linux/tile/tilepro/libc.abilist [GLIBC_2.22]:
	Likewise.
	* sysdeps/unix/sysv/linux/x86_64/64/libc.abilist [GLIBC_2.22]:
	Likewise.
	* sysdeps/unix/sysv/linux/x86_64/x32/libc.abilist [GLIBC_2.22]:
	Likewise.
	* sysdeps/unix/sysv/linux/hppa/libc.abilist [GLIBC_2.22]: Likewise.
	* sysdeps/unix/sysv/linux/nios2/libc.abilist [GLIBC_2.22]: Likewise.
This commit is contained in:
Adhemerval Zanella 2014-06-09 16:19:25 -03:00 committed by Adhemerval Zanella
parent 1c1e312520
commit fdb7d390dd
37 changed files with 703 additions and 114 deletions

View File

@ -1,3 +1,73 @@
2015-07-08 Adhemerval Zanella <adhemerval.zanella@linaro.org>
[BZ #6544]
[BZ #11216]
[BZ #12836]
[BZ #13151]
[BZ #13152]
[BZ #14292]
* include/stdio.h (fmemopen): Remove hidden prototype.
(__fmemopen): Add new hidden prototype.
* libio/Makefile: Add oldfmemopen object.
* libio/Versions [GLIBC_2.22]: Add new fmemopen symbol.
* libio/fmemopen.c (__fmemopen): Function rewrite to be POSIX
compliance.
* libio/oldfmemopen.c: New file: old fmemopen implementation for
symbol compatibility.
* stdio-common/Makefile [tests]: Add new tst-fmemopen3.
* stdio-common/psiginfo.c [psiginfo]: Call __fmemopen instead of
fmemopen.
* stdio-common/tst-fmemopen3.c: New file: more fmemopen tests, focus
on append and read mode.
* sysdeps/unix/sysv/linux/aarch64/libc.abilist [GLIBC_2.22]: Add
fmemopen.
* sysdeps/unix/sysv/linux/alpha/libc.abilist [GLIBC_2.22]: Likewise.
* sysdeps/unix/sysv/linux/arm/libc.abilist [GLIBC_2.22]: Likewise.
* sysdeps/unix/sysv/linux/i386/libc.abilist [GLIBC_2.22]: Likewise.
* sysdeps/unix/sysv/linux/ia64/libc.abilist [GLIBC_2.22]:
Likewise.
* sysdeps/unix/sysv/linux/m68k/coldfire/libc.abilist
[GLIBC_2.22]: Likewise.
* sysdeps/unix/sysv/linux/m68k/m680x0/libc.abilist [GLIBC_2.22]:
Likewise.
* sysdeps/unix/sysv/linux/microblaze/libc.abilist [GLIBC_2.22]:
Likewise.
* sysdeps/unix/sysv/linux/mips/mips32/fpu/libc.abilist
[GLIBC_2.22]: Likewise.
* sysdeps/unix/sysv/linux/mips/mips32/nofpu/libc.abilist
[GLIBC_2.22]: Likewise.
* sysdeps/unix/sysv/linux/mips/mips64/n32/libc.abilist
[GLIBC_2.22]: Likewise.
* sysdeps/unix/sysv/linux/mips/mips64/n64/libc.abilist
[GLIBC_2.22]: Likewise.
* sysdeps/unix/sysv/linux/powerpc/powerpc32/fpu/libc.abilist
[GLIBC_2.22]: Likewise.
* sysdeps/unix/sysv/linux/powerpc/powerpc32/nofpu/libc.abilist
[GLIBC_2.22]: Likewise.
* sysdeps/unix/sysv/linux/powerpc/powerpc64/libc.abilist
[GLIBC_2.22]: Likewise.
* sysdeps/unix/sysv/linux/s390/s390-32/libc.abilist [GLIBC_2.22]:
Likewise.
* sysdeps/unix/sysv/linux/s390/s390-64/libc.abilist [GLIBC_2.22]:
Likewise.
* sysdeps/unix/sysv/linux/sh/libc.abilist [GLIBC_2.22]: Likewise.
* sysdeps/unix/sysv/linux/sparc/sparc32/libc.abilist
[GLIBC_2.22]: Likewise.
* sysdeps/unix/sysv/linux/sparc/sparc64/libc.abilist
[GLIBC_2.22]: Likewise.
* sysdeps/unix/sysv/linux/tile/tilegx/tilegx32/libc.abilist
[GLIBC_2.22]: Likewise.
* sysdeps/unix/sysv/linux/tile/tilegx/tilegx64/libc.abilist
[GLIBC_2.22]: Likewise.
* sysdeps/unix/sysv/linux/tile/tilepro/libc.abilist [GLIBC_2.22]:
Likewise.
* sysdeps/unix/sysv/linux/x86_64/64/libc.abilist [GLIBC_2.22]:
Likewise.
* sysdeps/unix/sysv/linux/x86_64/x32/libc.abilist [GLIBC_2.22]:
Likewise.
* sysdeps/unix/sysv/linux/hppa/libc.abilist [GLIBC_2.22]: Likewise.
* sysdeps/unix/sysv/linux/nios2/libc.abilist [GLIBC_2.22]: Likewise.
2015-07-08 Carlos O'Donell <carlos@redhat.com> 2015-07-08 Carlos O'Donell <carlos@redhat.com>
[BZ #18643] [BZ #18643]

42
NEWS
View File

@ -9,24 +9,25 @@ Version 2.22
* The following bugs are resolved with this release: * The following bugs are resolved with this release:
438, 4719, 6792, 13028, 13064, 14094, 14841, 14906, 14958, 15319, 438, 4719, 6544, 6792, 11216, 12836, 13028, 13064, 13151, 13152, 14094,
15467, 15790, 15969, 16159, 16339, 16350, 16351, 16352, 16353, 16361, 14292, 14841, 14906, 14958, 15319, 15467, 15790, 15969, 16159, 16339,
16512, 16526, 16538, 16559, 16560, 16704, 16783, 16850, 17053, 17090, 16350, 16351, 16352, 16353, 16361, 16512, 16526, 16538, 16559, 16560,
17195, 17269, 17293, 17322, 17403, 17523, 17542, 17569, 17581, 17588, 16704, 16783, 16850, 17053, 17090, 17195, 17269, 17293, 17322, 17403,
17596, 17620, 17621, 17628, 17631, 17692, 17711, 17715, 17776, 17779, 17523, 17542, 17569, 17581, 17588, 17596, 17620, 17621, 17628, 17631,
17792, 17833, 17836, 17841, 17912, 17916, 17930, 17932, 17944, 17949, 17692, 17711, 17715, 17776, 17779, 17792, 17833, 17836, 17841, 17912,
17964, 17965, 17967, 17969, 17977, 17978, 17987, 17991, 17996, 17998, 17916, 17930, 17932, 17944, 17949, 17964, 17965, 17967, 17969, 17977,
17999, 18007, 18019, 18020, 18029, 18030, 18032, 18034, 18036, 18038, 17978, 17987, 17991, 17996, 17998, 17999, 18007, 18019, 18020, 18029,
18039, 18042, 18043, 18046, 18047, 18049, 18068, 18080, 18093, 18100, 18030, 18032, 18034, 18036, 18038, 18039, 18042, 18043, 18046, 18047,
18104, 18110, 18111, 18116, 18125, 18128, 18138, 18185, 18196, 18197, 18049, 18068, 18080, 18093, 18100, 18104, 18110, 18111, 18116, 18125,
18206, 18210, 18211, 18217, 18219, 18220, 18221, 18234, 18244, 18245, 18128, 18138, 18185, 18196, 18197, 18206, 18210, 18211, 18217, 18219,
18247, 18287, 18319, 18324, 18333, 18346, 18371, 18397, 18409, 18410, 18220, 18221, 18234, 18244, 18245, 18247, 18287, 18319, 18324, 18333,
18412, 18418, 18422, 18434, 18435, 18444, 18468, 18469, 18470, 18479, 18346, 18371, 18397, 18409, 18410, 18412, 18418, 18422, 18434, 18435,
18483, 18495, 18496, 18497, 18498, 18502, 18507, 18508, 18512, 18513, 18444, 18468, 18469, 18470, 18479, 18483, 18495, 18496, 18497, 18498,
18519, 18520, 18522, 18527, 18528, 18529, 18530, 18532, 18533, 18534, 18502, 18507, 18508, 18512, 18513, 18519, 18520, 18522, 18527, 18528,
18536, 18539, 18540, 18542, 18544, 18545, 18546, 18547, 18549, 18553, 18529, 18530, 18532, 18533, 18534, 18536, 18539, 18540, 18542, 18544,
18557, 18558, 18569, 18583, 18585, 18586, 18592, 18593, 18594, 18602, 18545, 18546, 18547, 18549, 18553, 18557, 18558, 18569, 18583, 18585,
18612, 18613, 18619, 18633, 18641, 18643. 18586, 18592, 18593, 18594, 18602, 18612, 18613, 18619, 18633, 18641.
18643.
* Cache information can be queried via sysconf() function on s390 e.g. with * Cache information can be queried via sysconf() function on s390 e.g. with
_SC_LEVEL1_ICACHE_SIZE as argument. _SC_LEVEL1_ICACHE_SIZE as argument.
@ -65,6 +66,11 @@ Version 2.22
Shared library libmvec.so is linked in as needed when using -lm (no need to Shared library libmvec.so is linked in as needed when using -lm (no need to
specify -lmvec explicitly for not static builds). specify -lmvec explicitly for not static builds).
Visit <https://sourceware.org/glibc/wiki/libmvec> for detailed information. Visit <https://sourceware.org/glibc/wiki/libmvec> for detailed information.
* A new fmemopen implementation has been added with the goal of POSIX
compliance. The new implementation fixes the following long-standing
issues: BZ#6544, BZ#11216, BZ#12836, BZ#13151, BZ#13152, and BZ#14292. The
old implementation is still present for use be by existing binaries.
Version 2.21 Version 2.21

View File

@ -197,6 +197,9 @@ gets (char *__str)
} }
# endif # endif
extern FILE * __fmemopen (void *buf, size_t len, const char *mode);
libc_hidden_proto (__fmemopen)
__END_DECLS __END_DECLS
# endif # endif

View File

@ -46,7 +46,7 @@ routines := \
__fbufsize __freading __fwriting __freadable __fwritable __flbf \ __fbufsize __freading __fwriting __freadable __fwritable __flbf \
__fpurge __fpending __fsetlocking \ __fpurge __fpending __fsetlocking \
\ \
libc_fatal fmemopen libc_fatal fmemopen oldfmemopen
tests = tst_swprintf tst_wprintf tst_swscanf tst_wscanf tst_getwc tst_putwc \ tests = tst_swprintf tst_wprintf tst_swscanf tst_wscanf tst_getwc tst_putwc \
tst_wprintf2 tst-widetext test-fmemopen tst-ext tst-ext2 \ tst_wprintf2 tst-widetext test-fmemopen tst-ext tst-ext2 \

View File

@ -148,6 +148,10 @@ libc {
GLIBC_2.4 { GLIBC_2.4 {
open_wmemstream; open_wmemstream;
} }
GLIBC_2.22 {
# f*
fmemopen;
}
GLIBC_PRIVATE { GLIBC_PRIVATE {
# Used by NPTL and librt # Used by NPTL and librt
__libc_fatal; __libc_fatal;

View File

@ -1,7 +1,6 @@
/* Fmemopen implementation. /* fmemopen implementation.
Copyright (C) 2000-2015 Free Software Foundation, Inc. Copyright (C) 2015 Free Software Foundation, Inc.
This file is part of the GNU C Library. This file is part of the GNU C Library.
Contributed by Hanno Mueller, kontakt@hanno.de, 2000.
The GNU C Library is free software; you can redistribute it and/or The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public modify it under the terms of the GNU Lesser General Public
@ -17,54 +16,10 @@
License along with the GNU C Library; if not, see License along with the GNU C Library; if not, see
<http://www.gnu.org/licenses/>. */ <http://www.gnu.org/licenses/>. */
/* /* fmemopen() from 2.22 and forward works as defined by POSIX. It also
* fmemopen() - "my" version of a string stream provides an older symbol, version 2.2.5, that behaves different regarding
* Hanno Mueller, kontakt@hanno.de SEEK_END (libio/oldfmemopen.c). */
*
*
* I needed fmemopen() for an application that I currently work on,
* but couldn't find it in libio. The following snippet of code is an
* attempt to implement what glibc's documentation describes.
*
*
*
* I already see some potential problems:
*
* - I never used the "original" fmemopen(). I am sure that "my"
* fmemopen() behaves differently than the original version.
*
* - The documentation doesn't say wether a string stream allows
* seeks. I checked the old fmemopen implementation in glibc's stdio
* directory, wasn't quite able to see what is going on in that
* source, but as far as I understand there was no seek there. For
* my application, I needed fseek() and ftell(), so it's here.
*
* - "append" mode and fseek(p, SEEK_END) have two different ideas
* about the "end" of the stream.
*
* As described in the documentation, when opening the file in
* "append" mode, the position pointer will be set to the first null
* character of the string buffer (yet the buffer may already
* contain more data). For fseek(), the last byte of the buffer is
* used as the end of the stream.
*
* - It is unclear to me what the documentation tries to say when it
* explains what happens when you use fmemopen with a NULL
* buffer.
*
* Quote: "fmemopen [then] allocates an array SIZE bytes long. This
* is really only useful if you are going to write things to the
* buffer and then read them back in again."
*
* What does that mean if the original fmemopen() did not allow
* seeking? How do you read what you just wrote without seeking back
* to the beginning of the stream?
*
* - I think there should be a second version of fmemopen() that does
* not add null characters for each write. (At least in my
* application, I am not actually using strings but binary data and
* so I don't need the stream to add null characters on its own.)
*/
#include <errno.h> #include <errno.h>
#include <libio.h> #include <libio.h>
@ -79,25 +34,23 @@
typedef struct fmemopen_cookie_struct fmemopen_cookie_t; typedef struct fmemopen_cookie_struct fmemopen_cookie_t;
struct fmemopen_cookie_struct struct fmemopen_cookie_struct
{ {
char *buffer; char *buffer; /* memory buffer. */
int mybuffer; int mybuffer; /* allocated my buffer? */
int binmode; int append; /* buffer open for append? */
size_t size; size_t size; /* buffer length in bytes. */
_IO_off64_t pos; _IO_off64_t pos; /* current position at the buffer. */
size_t maxpos; size_t maxpos; /* max position in buffer. */
}; };
static ssize_t static ssize_t
fmemopen_read (void *cookie, char *b, size_t s) fmemopen_read (void *cookie, char *b, size_t s)
{ {
fmemopen_cookie_t *c; fmemopen_cookie_t *c = (fmemopen_cookie_t *) cookie;
c = (fmemopen_cookie_t *) cookie; if (c->pos + s > c->maxpos)
if (c->pos + s > c->size)
{ {
if ((size_t) c->pos == c->size) if ((size_t) c->pos == c->maxpos)
return 0; return 0;
s = c->size - c->pos; s = c->size - c->pos;
} }
@ -115,29 +68,28 @@ fmemopen_read (void *cookie, char *b, size_t s)
static ssize_t static ssize_t
fmemopen_write (void *cookie, const char *b, size_t s) fmemopen_write (void *cookie, const char *b, size_t s)
{ {
fmemopen_cookie_t *c; fmemopen_cookie_t *c = (fmemopen_cookie_t *) cookie;;
_IO_off64_t pos = c->append ? c->maxpos : c->pos;
int addnullc; int addnullc;
c = (fmemopen_cookie_t *) cookie; addnullc = (s == 0 || b[s - 1] != '\0');
addnullc = c->binmode == 0 && (s == 0 || b[s - 1] != '\0'); if (pos + s + addnullc > c->size)
if (c->pos + s + addnullc > c->size)
{ {
if ((size_t) (c->pos + addnullc) >= c->size) if ((size_t) (c->pos + addnullc) >= c->size)
{ {
__set_errno (ENOSPC); __set_errno (ENOSPC);
return 0; return 0;
} }
s = c->size - c->pos - addnullc; s = c->size - pos - addnullc;
} }
memcpy (&(c->buffer[c->pos]), b, s); memcpy (&(c->buffer[pos]), b, s);
c->pos += s; pos += s;
if ((size_t) c->pos > c->maxpos) if ((size_t) pos > c->maxpos)
{ {
c->maxpos = c->pos; c->maxpos = pos;
if (addnullc) if (addnullc)
c->buffer[c->maxpos] = '\0'; c->buffer[c->maxpos] = '\0';
} }
@ -150,9 +102,7 @@ static int
fmemopen_seek (void *cookie, _IO_off64_t *p, int w) fmemopen_seek (void *cookie, _IO_off64_t *p, int w)
{ {
_IO_off64_t np; _IO_off64_t np;
fmemopen_cookie_t *c; fmemopen_cookie_t *c = (fmemopen_cookie_t *) cookie;
c = (fmemopen_cookie_t *) cookie;
switch (w) switch (w)
{ {
@ -165,7 +115,7 @@ fmemopen_seek (void *cookie, _IO_off64_t *p, int w)
break; break;
case SEEK_END: case SEEK_END:
np = (c->binmode ? c->size : c->maxpos) - *p; np = c->maxpos + *p;
break; break;
default: default:
@ -184,9 +134,7 @@ fmemopen_seek (void *cookie, _IO_off64_t *p, int w)
static int static int
fmemopen_close (void *cookie) fmemopen_close (void *cookie)
{ {
fmemopen_cookie_t *c; fmemopen_cookie_t *c = (fmemopen_cookie_t *) cookie;
c = (fmemopen_cookie_t *) cookie;
if (c->mybuffer) if (c->mybuffer)
free (c->buffer); free (c->buffer);
@ -197,18 +145,11 @@ fmemopen_close (void *cookie)
FILE * FILE *
fmemopen (void *buf, size_t len, const char *mode) __fmemopen (void *buf, size_t len, const char *mode)
{ {
cookie_io_functions_t iof; cookie_io_functions_t iof;
fmemopen_cookie_t *c; fmemopen_cookie_t *c;
if (__glibc_unlikely (len == 0))
{
einval:
__set_errno (EINVAL);
return NULL;
}
c = (fmemopen_cookie_t *) malloc (sizeof (fmemopen_cookie_t)); c = (fmemopen_cookie_t *) malloc (sizeof (fmemopen_cookie_t));
if (c == NULL) if (c == NULL)
return NULL; return NULL;
@ -231,26 +172,38 @@ fmemopen (void *buf, size_t len, const char *mode)
if (__glibc_unlikely ((uintptr_t) len > -(uintptr_t) buf)) if (__glibc_unlikely ((uintptr_t) len > -(uintptr_t) buf))
{ {
free (c); free (c);
goto einval; __set_errno (EINVAL);
return NULL;
} }
c->buffer = buf; c->buffer = buf;
if (mode[0] == 'w') /* POSIX states that w+ mode should truncate the buffer. */
if (mode[0] == 'w' && mode[1] == '+')
c->buffer[0] = '\0'; c->buffer[0] = '\0';
c->maxpos = strnlen (c->buffer, len); c->maxpos = strnlen (c->buffer, len);
} }
/* Mode | starting position (cookie::pos) | size (cookie::size)
------ |----------------------------------|-----------------------------
read | beginning of the buffer | size argument
write | beginning of the buffer | zero
append | first null or size buffer + 1 | first null or size argument
*/
c->size = len; c->size = len;
if (mode[0] == 'a') if (mode[0] == 'r')
c->maxpos = len;
c->append = mode[0] == 'a';
if (c->append)
c->pos = c->maxpos; c->pos = c->maxpos;
else else
c->pos = 0; c->pos = 0;
c->binmode = mode[0] != '\0' && mode[1] == 'b';
iof.read = fmemopen_read; iof.read = fmemopen_read;
iof.write = fmemopen_write; iof.write = fmemopen_write;
iof.seek = fmemopen_seek; iof.seek = fmemopen_seek;
@ -258,4 +211,5 @@ fmemopen (void *buf, size_t len, const char *mode)
return _IO_fopencookie (c, mode, iof); return _IO_fopencookie (c, mode, iof);
} }
libc_hidden_def (fmemopen) libc_hidden_def (__fmemopen)
versioned_symbol (libc, __fmemopen, fmemopen, GLIBC_2_22);

265
libio/oldfmemopen.c Normal file
View File

@ -0,0 +1,265 @@
/* Fmemopen implementation.
Copyright (C) 2000-2015 Free Software Foundation, Inc.
This file is part of the GNU C Library.
Contributed by Hanno Mueller, kontakt@hanno.de, 2000.
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/>. */
/*
* fmemopen() - "my" version of a string stream
* Hanno Mueller, kontakt@hanno.de
*
*
* I needed fmemopen() for an application that I currently work on,
* but couldn't find it in libio. The following snippet of code is an
* attempt to implement what glibc's documentation describes.
*
*
*
* I already see some potential problems:
*
* - I never used the "original" fmemopen(). I am sure that "my"
* fmemopen() behaves differently than the original version.
*
* - The documentation doesn't say wether a string stream allows
* seeks. I checked the old fmemopen implementation in glibc's stdio
* directory, wasn't quite able to see what is going on in that
* source, but as far as I understand there was no seek there. For
* my application, I needed fseek() and ftell(), so it's here.
*
* - "append" mode and fseek(p, SEEK_END) have two different ideas
* about the "end" of the stream.
*
* As described in the documentation, when opening the file in
* "append" mode, the position pointer will be set to the first null
* character of the string buffer (yet the buffer may already
* contain more data). For fseek(), the last byte of the buffer is
* used as the end of the stream.
*
* - It is unclear to me what the documentation tries to say when it
* explains what happens when you use fmemopen with a NULL
* buffer.
*
* Quote: "fmemopen [then] allocates an array SIZE bytes long. This
* is really only useful if you are going to write things to the
* buffer and then read them back in again."
*
* What does that mean if the original fmemopen() did not allow
* seeking? How do you read what you just wrote without seeking back
* to the beginning of the stream?
*
* - I think there should be a second version of fmemopen() that does
* not add null characters for each write. (At least in my
* application, I am not actually using strings but binary data and
* so I don't need the stream to add null characters on its own.)
*/
#include "libioP.h"
#if SHLIB_COMPAT (libc, GLIBC_2_2, GLIBC_2_22)
#include <errno.h>
#include <libio.h>
#include <stdio.h>
#include <stdlib.h>
#include <stdint.h>
#include <string.h>
#include <sys/types.h>
typedef struct fmemopen_cookie_struct fmemopen_cookie_t;
struct fmemopen_cookie_struct
{
char *buffer;
int mybuffer;
int binmode;
size_t size;
_IO_off64_t pos;
size_t maxpos;
};
static ssize_t
fmemopen_read (void *cookie, char *b, size_t s)
{
fmemopen_cookie_t *c;
c = (fmemopen_cookie_t *) cookie;
if (c->pos + s > c->size)
{
if ((size_t) c->pos == c->size)
return 0;
s = c->size - c->pos;
}
memcpy (b, &(c->buffer[c->pos]), s);
c->pos += s;
if ((size_t) c->pos > c->maxpos)
c->maxpos = c->pos;
return s;
}
static ssize_t
fmemopen_write (void *cookie, const char *b, size_t s)
{
fmemopen_cookie_t *c;
int addnullc;
c = (fmemopen_cookie_t *) cookie;
addnullc = c->binmode == 0 && (s == 0 || b[s - 1] != '\0');
if (c->pos + s + addnullc > c->size)
{
if ((size_t) (c->pos + addnullc) >= c->size)
{
__set_errno (ENOSPC);
return 0;
}
s = c->size - c->pos - addnullc;
}
memcpy (&(c->buffer[c->pos]), b, s);
c->pos += s;
if ((size_t) c->pos > c->maxpos)
{
c->maxpos = c->pos;
if (addnullc)
c->buffer[c->maxpos] = '\0';
}
return s;
}
static int
fmemopen_seek (void *cookie, _IO_off64_t *p, int w)
{
_IO_off64_t np;
fmemopen_cookie_t *c;
c = (fmemopen_cookie_t *) cookie;
switch (w)
{
case SEEK_SET:
np = *p;
break;
case SEEK_CUR:
np = c->pos + *p;
break;
case SEEK_END:
np = (c->binmode ? c->size : c->maxpos) - *p;
break;
default:
return -1;
}
if (np < 0 || (size_t) np > c->size)
return -1;
*p = c->pos = np;
return 0;
}
static int
fmemopen_close (void *cookie)
{
fmemopen_cookie_t *c;
c = (fmemopen_cookie_t *) cookie;
if (c->mybuffer)
free (c->buffer);
free (c);
return 0;
}
FILE *
__old_fmemopen (void *buf, size_t len, const char *mode)
{
cookie_io_functions_t iof;
fmemopen_cookie_t *c;
if (__glibc_unlikely (len == 0))
{
einval:
__set_errno (EINVAL);
return NULL;
}
c = (fmemopen_cookie_t *) malloc (sizeof (fmemopen_cookie_t));
if (c == NULL)
return NULL;
c->mybuffer = (buf == NULL);
if (c->mybuffer)
{
c->buffer = (char *) malloc (len);
if (c->buffer == NULL)
{
free (c);
return NULL;
}
c->buffer[0] = '\0';
c->maxpos = 0;
}
else
{
if (__glibc_unlikely ((uintptr_t) len > -(uintptr_t) buf))
{
free (c);
goto einval;
}
c->buffer = buf;
if (mode[0] == 'w')
c->buffer[0] = '\0';
c->maxpos = strnlen (c->buffer, len);
}
c->size = len;
if (mode[0] == 'a')
c->pos = c->maxpos;
else
c->pos = 0;
c->binmode = mode[0] != '\0' && mode[1] == 'b';
iof.read = fmemopen_read;
iof.write = fmemopen_write;
iof.seek = fmemopen_seek;
iof.close = fmemopen_close;
return _IO_fopencookie (c, mode, iof);
}
compat_symbol (libc, __old_fmemopen, fmemopen, GLIBC_2_2);
#endif

View File

@ -57,7 +57,7 @@ tests := tstscanf test_rdwr test-popen tstgetln test-fseek \
bug19 bug19a tst-popen2 scanf13 scanf14 scanf15 bug20 bug21 bug22 \ bug19 bug19a tst-popen2 scanf13 scanf14 scanf15 bug20 bug21 bug22 \
scanf16 scanf17 tst-setvbuf1 tst-grouping bug23 bug24 \ scanf16 scanf17 tst-setvbuf1 tst-grouping bug23 bug24 \
bug-vfprintf-nargs tst-long-dbl-fphex tst-fphex-wide tst-sprintf3 \ bug-vfprintf-nargs tst-long-dbl-fphex tst-fphex-wide tst-sprintf3 \
bug25 tst-printf-round bug23-2 bug23-3 bug23-4 bug26 bug25 tst-printf-round bug23-2 bug23-3 bug23-4 bug26 tst-fmemopen3
test-srcs = tst-unbputc tst-printf test-srcs = tst-unbputc tst-printf

View File

@ -60,7 +60,7 @@ void
psiginfo (const siginfo_t *pinfo, const char *s) psiginfo (const siginfo_t *pinfo, const char *s)
{ {
char buf[512]; char buf[512];
FILE *fp = fmemopen (buf, sizeof (buf), "w"); FILE *fp = __fmemopen (buf, sizeof (buf), "w");
if (fp == NULL) if (fp == NULL)
{ {
const char *colon; const char *colon;

View File

@ -0,0 +1,206 @@
/* fmemopen tests for append and read mode.
Copyright (C) 2015 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 <assert.h>
#include <stdio.h>
#include <string.h>
#include <sys/types.h>
static void
print_buffer (const char *s, size_t n)
{
size_t i;
for (i=0; i<n; ++i)
printf ("0x%02X (%c), ", s[i], s[i]);
}
/* This test check append mode initial position (a/a+) based on POSIX defition
(BZ#6544 and BZ#13151). */
static int
do_test_write_append (const char *mode)
{
char buf[32] = "testing buffer";
char exp[32] = "testing bufferXX";
FILE *fp = fmemopen (buf, sizeof (buf), mode);
fflush (fp);
fprintf (fp, "X");
fseek (fp, 0, SEEK_SET);
fprintf (fp, "X");
fclose (fp);
if (strcmp (buf, exp) != 0)
{
printf ("%s: check failed: %s != %s\n", __FUNCTION__, buf, exp);
return 1;
}
return 0;
}
/* This test check append mode initial position (a/a+) based on POSIX defition
(BZ#6544 and BZ#13151) for buffer without null byte end. */
static int
do_test_write_append_without_null (const char *mode)
{
char buf[] = { 0x55, 0x55, 0x55, 0x55, 0x55, 0x55, 0x55, 0x55 };
char exp[] = { 0x55, 0x55, 0x55, 0x55, 0x55, 0x55, 0x55, 0x55 };
/* If '\0' is not found in buffer, POSIX states that SEEK_SET should be
the size argument. */
FILE *fp = fmemopen (buf, sizeof (buf) - 2, "a");
fflush (fp);
fputc (0x70, fp);
fseek (fp, 0, SEEK_SET);
fputc (0x70, fp);
fputc (0x70, fp);
fclose (fp);
/* POSIX also states that a write operation on the stream shall not advance
the current buffer size beyond the size given in fmemopen, so the string
should be same. */
if (memcmp (buf, exp, sizeof (buf)) != 0)
{
printf ("%s: check failed: ", __FUNCTION__);
print_buffer (buf, sizeof (buf));
printf ("!= ");
print_buffer (exp, sizeof (exp));
printf ("\n");
return 1;
}
return 0;
}
/* This test check for initial position and feek value for fmemopen objects
opened with append mode. */
static int
do_test_read_append (void)
{
char buf[32] = "testing buffer";
size_t buflen = strlen (buf);
long fpos;
/* POSIX defines for 'a+' the initial position is the first null byte. */
FILE *fp = fmemopen (buf, sizeof (buf), "a+");
fpos = ftell (fp);
if (fpos != buflen)
{
printf ("%s: ftell|SEEK_SET (fp) %li != strlen (%s) %zu\n",
__FUNCTION__, fpos, buf, buflen);
fclose (fp);
return 1;
}
fseek (fp, 0, SEEK_END);
if (fpos != buflen)
{
printf ("%s: ftell|SEEK_END (fp) %li != strlen (%s) %zu\n",
__FUNCTION__, fpos, buf, buflen);
fclose (fp);
return 1;
}
fclose (fp);
/* Check if attempting to read past the current size, defined as strlen (buf)
yield an EOF. */
fp = fmemopen (buf, sizeof (buf), "a+");
if (getc(fp) != EOF)
{
printf ("%s: getc(fp) != EOF\n", __FUNCTION__);
fclose (fp);
return -1;
}
fclose (fp);
return 0;
}
/* This test check for fseek (SEEK_END) using negative offsets (BZ#14292). The
starting position of descriptor is different base on the opening mode. */
static int
do_test_read_seek_neg (const char *mode, const char *expected)
{
char buf[] = "abcdefghijklmnopqrstuvxz0123456789";
char tmp[10];
size_t tmps = sizeof (tmps);
long offset = -11;
FILE *fp = fmemopen (buf, sizeof (buf), mode);
fseek (fp, offset, SEEK_END);
fread (tmp, tmps, 1, fp);
if (memcmp (tmp, expected, tmps) != 0)
{
printf ("%s: fmemopen(%s) - fseek (fp, %li, SEEK_END):\n",
__FUNCTION__, mode, offset);
printf (" returned: ");
print_buffer (tmp, tmps);
printf ("\n");
printf (" expected: ");
print_buffer (expected, tmps);
printf ("\n");
return 1;
}
fclose (fp);
return 0;
}
static int
do_test_read_seek_negative (void)
{
int ret = 0;
/* 'r' and 'w' modes defines the initial position at the buffer start and
seek with SEEK_END shall seek relative to its size give in fmemopen
call. The expected tmp result is 0 to 9 *without* the ending null */
ret += do_test_read_seek_neg ("r", "0123456789");
/* 'a+' mode sets the initial position at the first null byte in buffer and
SEEK_END shall seek relative to its size as well. The expected result is
z012345678, since SEEK_END plus a+ start at '\0', not size. */
ret += do_test_read_seek_neg ("a+", "z012345678");
return ret;
}
static int
do_test (void)
{
int ret = 0;
ret += do_test_write_append ("a");
ret += do_test_write_append_without_null ("a");
ret += do_test_write_append ("a+");
ret += do_test_write_append_without_null ("a+");
ret += do_test_read_append ();
ret += do_test_read_seek_negative ();
return ret;
}
#define TEST_FUNCTION do_test ()
#include "../test-skeleton.c"

View File

@ -2081,3 +2081,6 @@ GLIBC_2.18
GLIBC_2.18 A GLIBC_2.18 A
__cxa_thread_atexit_impl F __cxa_thread_atexit_impl F
_mcount F _mcount F
GLIBC_2.22
GLIBC_2.22 A
fmemopen F

View File

@ -1822,6 +1822,9 @@ GLIBC_2.17
GLIBC_2.18 GLIBC_2.18
GLIBC_2.18 A GLIBC_2.18 A
__cxa_thread_atexit_impl F __cxa_thread_atexit_impl F
GLIBC_2.22
GLIBC_2.22 A
fmemopen F
GLIBC_2.2 GLIBC_2.2
GLIBC_2.2 A GLIBC_2.2 A
_IO_adjust_wcolumn F _IO_adjust_wcolumn F

View File

@ -89,6 +89,9 @@ GLIBC_2.17
GLIBC_2.18 GLIBC_2.18
GLIBC_2.18 A GLIBC_2.18 A
__cxa_thread_atexit_impl F __cxa_thread_atexit_impl F
GLIBC_2.22
GLIBC_2.22 A
fmemopen F
GLIBC_2.4 GLIBC_2.4
GLIBC_2.4 A GLIBC_2.4 A
_Exit F _Exit F

View File

@ -95,6 +95,9 @@ GLIBC_2.18
GLIBC_2.19 GLIBC_2.19
GLIBC_2.19 A GLIBC_2.19 A
fanotify_mark F fanotify_mark F
GLIBC_2.22
GLIBC_2.22 A
fmemopen F
GLIBC_2.2 GLIBC_2.2
GLIBC_2.2 A GLIBC_2.2 A
_Exit F _Exit F

View File

@ -2023,6 +2023,9 @@ GLIBC_2.2.4
GLIBC_2.2.6 GLIBC_2.2.6
GLIBC_2.2.6 A GLIBC_2.2.6 A
__nanosleep F __nanosleep F
GLIBC_2.22
GLIBC_2.22 A
fmemopen F
GLIBC_2.3 GLIBC_2.3
GLIBC_2.3 A GLIBC_2.3 A
__ctype_b_loc F __ctype_b_loc F

View File

@ -1881,6 +1881,9 @@ GLIBC_2.2.6
GLIBC_2.2.6 A GLIBC_2.2.6 A
__nanosleep F __nanosleep F
getunwind F getunwind F
GLIBC_2.22
GLIBC_2.22 A
fmemopen F
GLIBC_2.3 GLIBC_2.3
GLIBC_2.3 A GLIBC_2.3 A
__ctype_b_loc F __ctype_b_loc F

View File

@ -90,6 +90,9 @@ GLIBC_2.17
GLIBC_2.18 GLIBC_2.18
GLIBC_2.18 A GLIBC_2.18 A
__cxa_thread_atexit_impl F __cxa_thread_atexit_impl F
GLIBC_2.22
GLIBC_2.22 A
fmemopen F
GLIBC_2.4 GLIBC_2.4
GLIBC_2.4 A GLIBC_2.4 A
_Exit F _Exit F

View File

@ -1979,6 +1979,9 @@ GLIBC_2.2.4
GLIBC_2.2.6 GLIBC_2.2.6
GLIBC_2.2.6 A GLIBC_2.2.6 A
__nanosleep F __nanosleep F
GLIBC_2.22
GLIBC_2.22 A
fmemopen F
GLIBC_2.3 GLIBC_2.3
GLIBC_2.3 A GLIBC_2.3 A
__ctype_b_loc F __ctype_b_loc F

View File

@ -2080,3 +2080,6 @@ GLIBC_2.18
xencrypt F xencrypt F
xprt_register F xprt_register F
xprt_unregister F xprt_unregister F
GLIBC_2.22
GLIBC_2.22 A
fmemopen F

View File

@ -1951,6 +1951,9 @@ GLIBC_2.2.4
GLIBC_2.2.6 GLIBC_2.2.6
GLIBC_2.2.6 A GLIBC_2.2.6 A
__nanosleep F __nanosleep F
GLIBC_2.22
GLIBC_2.22 A
fmemopen F
GLIBC_2.3 GLIBC_2.3
GLIBC_2.3 A GLIBC_2.3 A
__ctype_b_loc F __ctype_b_loc F

View File

@ -1949,6 +1949,9 @@ GLIBC_2.2.4
GLIBC_2.2.6 GLIBC_2.2.6
GLIBC_2.2.6 A GLIBC_2.2.6 A
__nanosleep F __nanosleep F
GLIBC_2.22
GLIBC_2.22 A
fmemopen F
GLIBC_2.3 GLIBC_2.3
GLIBC_2.3 A GLIBC_2.3 A
__ctype_b_loc F __ctype_b_loc F

View File

@ -1947,6 +1947,9 @@ GLIBC_2.2.4
GLIBC_2.2.6 GLIBC_2.2.6
GLIBC_2.2.6 A GLIBC_2.2.6 A
__nanosleep F __nanosleep F
GLIBC_2.22
GLIBC_2.22 A
fmemopen F
GLIBC_2.3 GLIBC_2.3
GLIBC_2.3 A GLIBC_2.3 A
__ctype_b_loc F __ctype_b_loc F

View File

@ -1941,6 +1941,9 @@ GLIBC_2.2.4
GLIBC_2.2.6 GLIBC_2.2.6
GLIBC_2.2.6 A GLIBC_2.2.6 A
__nanosleep F __nanosleep F
GLIBC_2.22
GLIBC_2.22 A
fmemopen F
GLIBC_2.3 GLIBC_2.3
GLIBC_2.3 A GLIBC_2.3 A
__ctype_b_loc F __ctype_b_loc F

View File

@ -2121,3 +2121,6 @@ GLIBC_2.21
xencrypt F xencrypt F
xprt_register F xprt_register F
xprt_unregister F xprt_unregister F
GLIBC_2.22
GLIBC_2.22 A
fmemopen F

View File

@ -1983,6 +1983,9 @@ GLIBC_2.2.4
GLIBC_2.2.6 GLIBC_2.2.6
GLIBC_2.2.6 A GLIBC_2.2.6 A
__nanosleep F __nanosleep F
GLIBC_2.22
GLIBC_2.22 A
fmemopen F
GLIBC_2.3 GLIBC_2.3
GLIBC_2.3 A GLIBC_2.3 A
__ctype_b_loc F __ctype_b_loc F

View File

@ -1989,6 +1989,9 @@ GLIBC_2.2.4
GLIBC_2.2.6 GLIBC_2.2.6
GLIBC_2.2.6 A GLIBC_2.2.6 A
__nanosleep F __nanosleep F
GLIBC_2.22
GLIBC_2.22 A
fmemopen F
GLIBC_2.3 GLIBC_2.3
GLIBC_2.3 A GLIBC_2.3 A
__ctype_b_loc F __ctype_b_loc F

View File

@ -90,6 +90,9 @@ GLIBC_2.17
GLIBC_2.18 GLIBC_2.18
GLIBC_2.18 A GLIBC_2.18 A
__cxa_thread_atexit_impl F __cxa_thread_atexit_impl F
GLIBC_2.22
GLIBC_2.22 A
fmemopen F
GLIBC_2.3 GLIBC_2.3
GLIBC_2.3 A GLIBC_2.3 A
_Exit F _Exit F

View File

@ -1984,6 +1984,9 @@ GLIBC_2.2.4
GLIBC_2.2.6 GLIBC_2.2.6
GLIBC_2.2.6 A GLIBC_2.2.6 A
__nanosleep F __nanosleep F
GLIBC_2.22
GLIBC_2.22 A
fmemopen F
GLIBC_2.3 GLIBC_2.3
GLIBC_2.3 A GLIBC_2.3 A
__ctype_b_loc F __ctype_b_loc F

View File

@ -1880,6 +1880,9 @@ GLIBC_2.2.4
GLIBC_2.2.6 GLIBC_2.2.6
GLIBC_2.2.6 A GLIBC_2.2.6 A
__nanosleep F __nanosleep F
GLIBC_2.22
GLIBC_2.22 A
fmemopen F
GLIBC_2.3 GLIBC_2.3
GLIBC_2.3 A GLIBC_2.3 A
__ctype_b_loc F __ctype_b_loc F

View File

@ -1864,6 +1864,9 @@ GLIBC_2.2.4
GLIBC_2.2.6 GLIBC_2.2.6
GLIBC_2.2.6 A GLIBC_2.2.6 A
__nanosleep F __nanosleep F
GLIBC_2.22
GLIBC_2.22 A
fmemopen F
GLIBC_2.3 GLIBC_2.3
GLIBC_2.3 A GLIBC_2.3 A
__ctype_b_loc F __ctype_b_loc F

View File

@ -1975,6 +1975,9 @@ GLIBC_2.2.4
GLIBC_2.2.6 GLIBC_2.2.6
GLIBC_2.2.6 A GLIBC_2.2.6 A
__nanosleep F __nanosleep F
GLIBC_2.22
GLIBC_2.22 A
fmemopen F
GLIBC_2.3 GLIBC_2.3
GLIBC_2.3 A GLIBC_2.3 A
__ctype_b_loc F __ctype_b_loc F

View File

@ -1908,6 +1908,9 @@ GLIBC_2.2.4
GLIBC_2.2.6 GLIBC_2.2.6
GLIBC_2.2.6 A GLIBC_2.2.6 A
__nanosleep F __nanosleep F
GLIBC_2.22
GLIBC_2.22 A
fmemopen F
GLIBC_2.3 GLIBC_2.3
GLIBC_2.3 A GLIBC_2.3 A
__ctype_b_loc F __ctype_b_loc F

View File

@ -2091,3 +2091,6 @@ GLIBC_2.17
GLIBC_2.18 GLIBC_2.18
GLIBC_2.18 A GLIBC_2.18 A
__cxa_thread_atexit_impl F __cxa_thread_atexit_impl F
GLIBC_2.22
GLIBC_2.22 A
fmemopen F

View File

@ -2091,3 +2091,6 @@ GLIBC_2.17
GLIBC_2.18 GLIBC_2.18
GLIBC_2.18 A GLIBC_2.18 A
__cxa_thread_atexit_impl F __cxa_thread_atexit_impl F
GLIBC_2.22
GLIBC_2.22 A
fmemopen F

View File

@ -2091,3 +2091,6 @@ GLIBC_2.17
GLIBC_2.18 GLIBC_2.18
GLIBC_2.18 A GLIBC_2.18 A
__cxa_thread_atexit_impl F __cxa_thread_atexit_impl F
GLIBC_2.22
GLIBC_2.22 A
fmemopen F

View File

@ -1854,6 +1854,9 @@ GLIBC_2.2.5
GLIBC_2.2.6 GLIBC_2.2.6
GLIBC_2.2.6 A GLIBC_2.2.6 A
__nanosleep F __nanosleep F
GLIBC_2.22
GLIBC_2.22 A
fmemopen F
GLIBC_2.3 GLIBC_2.3
GLIBC_2.3 A GLIBC_2.3 A
__ctype_b_loc F __ctype_b_loc F

View File

@ -2089,3 +2089,6 @@ GLIBC_2.17
GLIBC_2.18 GLIBC_2.18
GLIBC_2.18 A GLIBC_2.18 A
__cxa_thread_atexit_impl F __cxa_thread_atexit_impl F
GLIBC_2.22
GLIBC_2.22 A
fmemopen F