glibc i zwisy poldka

[Jakub Bogusz]

On Fri, Apr 08, 2005 at 03:12:19PM +0200, Arkadiusz Miskiewicz wrote:
> W załączniku prosty testcase,
> 
> na 2.3.5 daje:
> zfseek (0x8049aa0, 0, 0, 1) = 0
> 1: 0
> zfseek (0x8049aa0, 0, 0, 1) = 0
> 2: / -1
> (ftell zwraca -1)
> 
> na 2.3.4
> zfseek (0x96e0050, 0, 0, 1) = 0
> 1: 0
> 2: / 1
> (ftell zwraca prawdę)
> 
> Test przez:
> gcc testcookie.c -lz -Wall; ./a.out jakis.gzipniety.plik.gz
> 
> poldek zwisa dlatego, że dostaje od ftell -1 zamiast czegoś sensownego w 
> jednym miejscu i się zapętla na amen (nie ma sprawdzania co ftell zwróciło).

Pewnie chodzi zmiany w libio/iofopncook.c (pomijam dodane testy, do
znalezienia w źródłach lub CVS).

2005-01-19  Jakub Jelinek  <jakub w redhat.com>

	[BZ #730]
	* libio/iofopncook.c (_IO_cookie_seekoff): Add prototype.

2005-01-05  Ulrich Drepper  <drepper w redhat.com>

	[BZ #730]
	* libio/iofopncook.c (_IO_cookie_seekoff): Define.  Mark offset as
	invalid to disable optimizations in fileops which won't work here.
	(_IO_cookie_jumps): Use it.
	(_IO_old_cookie_jumps): Likewise.
	* libio/fmemopen.c (fmemopen_seek): Result must be returned in *P,
	not the return value.
	* stdio-common/Makefile (tests): Add tst-fmemopen2.
	* stdio-common/tst-fmemopen2.c: New file.

diff -Nurp glibc-2.3.4/libio/fmemopen.c glibc-2.3.5/libio/fmemopen.c
--- glibc-2.3.4/libio/fmemopen.c	2002-08-25 04:47:57.000000000 +0200
+++ glibc-2.3.5/libio/fmemopen.c	2005-03-01 21:57:17.000000000 +0100
@@ -1,5 +1,5 @@
 /* Fmemopen implementation.
-   Copyright (C) 2000, 2002 Free Software Foundation, Inc.
+   Copyright (C) 2000, 2002, 2005 Free Software Foundation, Inc.
    This file is part of the GNU C Library.
    Contributed by  Hanno Mueller, kontakt w hanno.de, 2000.
 
@@ -27,8 +27,6 @@
  * but couldn't find it in libio. The following snippet of code is an
  * attempt to implement what glibc's documentation describes.
  *
- * No, it isn't really tested yet. :-)
- *
  *
  *
  * I already see some potential problems:
@@ -73,6 +71,7 @@
 #include <libio.h>
 #include <stdio.h>
 #include <stdlib.h>
+#include <stdint.h>
 #include <string.h>
 #include <sys/types.h>
 #include "libioP.h"
@@ -166,7 +165,7 @@ fmemopen_seek (void *cookie, _IO_off64_t
       break;
 
     case SEEK_END:
-      np = c->size - *p;
+      np = c->maxpos - *p;
       break;
 
     default:
@@ -176,9 +175,9 @@ fmemopen_seek (void *cookie, _IO_off64_t
   if (np < 0 || (size_t) np > c->size)
     return -1;
 
-  c->pos = np;
+  *p = c->pos = np;
 
-  return np;
+  return 0;
 }
 
 
@@ -203,6 +202,13 @@ fmemopen (void *buf, size_t len, const c
   cookie_io_functions_t iof;
   fmemopen_cookie_t *c;
 
+  if (len == 0)
+    {
+    einval:
+      __set_errno (EINVAL);
+      return NULL;
+    }
+
   c = (fmemopen_cookie_t *) malloc (sizeof (fmemopen_cookie_t));
   if (c == NULL)
     return NULL;
@@ -220,7 +226,12 @@ fmemopen (void *buf, size_t len, const c
       c->buffer[0] = '\0';
     }
   else
-    c->buffer = buf;
+    {
+      if ((uintptr_t) len > -(uintptr_t) buf)
+	goto einval;
+
+      c->buffer = buf;
+    }
 
   c->size = len;
 
diff -Nurp glibc-2.3.4/libio/iofopncook.c glibc-2.3.5/libio/iofopncook.c
--- glibc-2.3.4/libio/iofopncook.c	2004-03-10 10:28:25.000000000 +0100
+++ glibc-2.3.5/libio/iofopncook.c	2005-02-16 10:45:20.000000000 +0100
@@ -36,6 +36,8 @@ static _IO_ssize_t _IO_cookie_read (regi
 static _IO_ssize_t _IO_cookie_write (register _IO_FILE* fp,
 				     const void* buf, _IO_ssize_t size);
 static _IO_off64_t _IO_cookie_seek (_IO_FILE *fp, _IO_off64_t offset, int dir);
+static _IO_off64_t _IO_cookie_seekoff (_IO_FILE *fp, _IO_off64_t offset,
+				       int dir, int mode);
 static int _IO_cookie_close (_IO_FILE* fp);
 
 static _IO_ssize_t
@@ -94,6 +96,20 @@ _IO_cookie_close (fp)
 }
 
 
+static _IO_off64_t
+_IO_cookie_seekoff (fp, offset, dir, mode)
+     _IO_FILE *fp;
+     _IO_off64_t offset;
+     int dir;
+     int mode;
+{
+  /* We must force the fileops code to always use seek to determine
+     the position.  */
+  fp->_offset = _IO_pos_BAD;
+  return INTUSE(_IO_file_seekoff) (fp, offset, dir, mode);
+}
+
+
 static const struct _IO_jump_t _IO_cookie_jumps = {
   JUMP_INIT_DUMMY,
   JUMP_INIT(finish, INTUSE(_IO_file_finish)),
@@ -103,7 +119,7 @@ static const struct _IO_jump_t _IO_cooki
   JUMP_INIT(pbackfail, INTUSE(_IO_default_pbackfail)),
   JUMP_INIT(xsputn, INTUSE(_IO_file_xsputn)),
   JUMP_INIT(xsgetn, INTUSE(_IO_default_xsgetn)),
-  JUMP_INIT(seekoff, INTUSE(_IO_file_seekoff)),
+  JUMP_INIT(seekoff, _IO_cookie_seekoff),
   JUMP_INIT(seekpos, _IO_default_seekpos),
   JUMP_INIT(setbuf, INTUSE(_IO_file_setbuf)),
   JUMP_INIT(sync, INTUSE(_IO_file_sync)),
@@ -223,7 +239,7 @@ static const struct _IO_jump_t _IO_old_c
   JUMP_INIT(pbackfail, INTUSE(_IO_default_pbackfail)),
   JUMP_INIT(xsputn, INTUSE(_IO_file_xsputn)),
   JUMP_INIT(xsgetn, INTUSE(_IO_default_xsgetn)),
-  JUMP_INIT(seekoff, INTUSE(_IO_file_seekoff)),
+  JUMP_INIT(seekoff, _IO_cookie_seekoff),
   JUMP_INIT(seekpos, _IO_default_seekpos),
   JUMP_INIT(setbuf, INTUSE(_IO_file_setbuf)),
   JUMP_INIT(sync, INTUSE(_IO_file_sync)),


-- 
Jakub Bogusz    http://cyber.cs.net.pl/~qboosh/