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.

37 files changed, 703 insertions, 114 deletions

diff --git a/ChangeLog b/ChangeLog
index 0ed1cf361d..1cf34d58d4 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -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>
 
 	[BZ #18643]
diff --git a/NEWS b/NEWS
index 23388ae9a6..ae0b753cde 100644
--- a/NEWS
+++ b/NEWS
@@ -9,24 +9,25 @@ Version 2.22
 
 * The following bugs are resolved with this release:
 
-  438, 4719, 6792, 13028, 13064, 14094, 14841, 14906, 14958, 15319,
-  15467, 15790, 15969, 16159, 16339, 16350, 16351, 16352, 16353, 16361,
-  16512, 16526, 16538, 16559, 16560, 16704, 16783, 16850, 17053, 17090,
-  17195, 17269, 17293, 17322, 17403, 17523, 17542, 17569, 17581, 17588,
-  17596, 17620, 17621, 17628, 17631, 17692, 17711, 17715, 17776, 17779,
-  17792, 17833, 17836, 17841, 17912, 17916, 17930, 17932, 17944, 17949,
-  17964, 17965, 17967, 17969, 17977, 17978, 17987, 17991, 17996, 17998,
-  17999, 18007, 18019, 18020, 18029, 18030, 18032, 18034, 18036, 18038,
-  18039, 18042, 18043, 18046, 18047, 18049, 18068, 18080, 18093, 18100,
-  18104, 18110, 18111, 18116, 18125, 18128, 18138, 18185, 18196, 18197,
-  18206, 18210, 18211, 18217, 18219, 18220, 18221, 18234, 18244, 18245,
-  18247, 18287, 18319, 18324, 18333, 18346, 18371, 18397, 18409, 18410,
-  18412, 18418, 18422, 18434, 18435, 18444, 18468, 18469, 18470, 18479,
-  18483, 18495, 18496, 18497, 18498, 18502, 18507, 18508, 18512, 18513,
-  18519, 18520, 18522, 18527, 18528, 18529, 18530, 18532, 18533, 18534,
-  18536, 18539, 18540, 18542, 18544, 18545, 18546, 18547, 18549, 18553,
-  18557, 18558, 18569, 18583, 18585, 18586, 18592, 18593, 18594, 18602,
-  18612, 18613, 18619, 18633, 18641, 18643.
+  438, 4719, 6544, 6792, 11216, 12836, 13028, 13064, 13151, 13152, 14094,
+  14292, 14841, 14906, 14958, 15319, 15467, 15790, 15969, 16159, 16339,
+  16350, 16351, 16352, 16353, 16361, 16512, 16526, 16538, 16559, 16560,
+  16704, 16783, 16850, 17053, 17090, 17195, 17269, 17293, 17322, 17403,
+  17523, 17542, 17569, 17581, 17588, 17596, 17620, 17621, 17628, 17631,
+  17692, 17711, 17715, 17776, 17779, 17792, 17833, 17836, 17841, 17912,
+  17916, 17930, 17932, 17944, 17949, 17964, 17965, 17967, 17969, 17977,
+  17978, 17987, 17991, 17996, 17998, 17999, 18007, 18019, 18020, 18029,
+  18030, 18032, 18034, 18036, 18038, 18039, 18042, 18043, 18046, 18047,
+  18049, 18068, 18080, 18093, 18100, 18104, 18110, 18111, 18116, 18125,
+  18128, 18138, 18185, 18196, 18197, 18206, 18210, 18211, 18217, 18219,
+  18220, 18221, 18234, 18244, 18245, 18247, 18287, 18319, 18324, 18333,
+  18346, 18371, 18397, 18409, 18410, 18412, 18418, 18422, 18434, 18435,
+  18444, 18468, 18469, 18470, 18479, 18483, 18495, 18496, 18497, 18498,
+  18502, 18507, 18508, 18512, 18513, 18519, 18520, 18522, 18527, 18528,
+  18529, 18530, 18532, 18533, 18534, 18536, 18539, 18540, 18542, 18544,
+  18545, 18546, 18547, 18549, 18553, 18557, 18558, 18569, 18583, 18585,
+  18586, 18592, 18593, 18594, 18602, 18612, 18613, 18619, 18633, 18641.
+  18643.
 
 * Cache information can be queried via sysconf() function on s390 e.g. with
   _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
   specify -lmvec explicitly for not static builds).
   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
 
diff --git a/include/stdio.h b/include/stdio.h
index 5e50e63b70..31718f953d 100644
--- a/include/stdio.h
+++ b/include/stdio.h
@@ -197,6 +197,9 @@ gets (char *__str)
 }
 #  endif
 
+extern FILE * __fmemopen (void *buf, size_t len, const char *mode);
+libc_hidden_proto (__fmemopen)
+
 __END_DECLS
 # endif
 
diff --git a/libio/Makefile b/libio/Makefile
index 097cfaedda..7b3bcf90fe 100644
--- a/libio/Makefile
+++ b/libio/Makefile
@@ -46,7 +46,7 @@ routines	:=							      \
 	__fbufsize __freading __fwriting __freadable __fwritable __flbf	      \
 	__fpurge __fpending __fsetlocking				      \
 									      \
-	libc_fatal fmemopen
+	libc_fatal fmemopen oldfmemopen
 
 tests = tst_swprintf tst_wprintf tst_swscanf tst_wscanf tst_getwc tst_putwc   \
 	tst_wprintf2 tst-widetext test-fmemopen tst-ext tst-ext2 \
diff --git a/libio/Versions b/libio/Versions
index 8df89d2150..2a1d6e6c85 100644
--- a/libio/Versions
+++ b/libio/Versions
@@ -148,6 +148,10 @@ libc {
   GLIBC_2.4 {
     open_wmemstream;
   }
+  GLIBC_2.22 {
+    # f*
+    fmemopen;
+  }
   GLIBC_PRIVATE {
     # Used by NPTL and librt
     __libc_fatal;
diff --git a/libio/fmemopen.c b/libio/fmemopen.c
index 06e5ab8002..e6e6a49f76 100644
--- a/libio/fmemopen.c
+++ b/libio/fmemopen.c
@@ -1,7 +1,6 @@
-/* Fmemopen implementation.
-   Copyright (C) 2000-2015 Free Software Foundation, Inc.
+/* fmemopen implementation.
+   Copyright (C) 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
@@ -17,54 +16,10 @@
    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.)
- */
+/* fmemopen() from 2.22 and forward works as defined by POSIX.  It also
+   provides an older symbol, version 2.2.5, that behaves different regarding
+   SEEK_END (libio/oldfmemopen.c).  */
+
 
 #include <errno.h>
 #include <libio.h>
@@ -79,25 +34,23 @@
 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;
+  char        *buffer;   /* memory buffer.  */
+  int         mybuffer;  /* allocated my buffer?  */
+  int         append;    /* buffer open for append?  */
+  size_t      size;      /* buffer length in bytes.  */
+  _IO_off64_t pos;       /* current position at the buffer.  */
+  size_t      maxpos;    /* max position in buffer.  */
 };
 
 
 static ssize_t
 fmemopen_read (void *cookie, char *b, size_t s)
 {
-  fmemopen_cookie_t *c;
-
-  c = (fmemopen_cookie_t *) cookie;
+  fmemopen_cookie_t *c = (fmemopen_cookie_t *) cookie;
 
-  if (c->pos + s > c->size)
+  if (c->pos + s > c->maxpos)
     {
-      if ((size_t) c->pos == c->size)
+      if ((size_t) c->pos == c->maxpos)
 	return 0;
       s = c->size - c->pos;
     }
@@ -115,29 +68,28 @@ fmemopen_read (void *cookie, char *b, size_t s)
 static ssize_t
 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;
 
-  c = (fmemopen_cookie_t *) cookie;
-
-  addnullc = c->binmode == 0 && (s == 0 || b[s - 1] != '\0');
+  addnullc = (s == 0 || b[s - 1] != '\0');
 
-  if (c->pos + s + addnullc > c->size)
+  if (pos + s + addnullc > c->size)
     {
       if ((size_t) (c->pos + addnullc) >= c->size)
 	{
 	  __set_errno (ENOSPC);
 	  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);