From: cgf AT cygnus DOT com (Christopher Faylor)
Subject: Re: Memory leaks in cygwin.dll
26 Aug 1998 11:42:08 -0700
Message-ID: <19980826142247.A31674.cygnus.cygwin32.developers@cygnus.com>
References: <01BDD130 DOT DB72EF60 AT sos>
Mime-Version: 1.0
Content-Type: text/plain; charset=us-ascii
To: Sergey Okhapkin <sos AT prospect DOT com DOT ru>,
        "cygwin32-developers AT cygnus DOT com" <cygwin32-developers AT cygnus DOT com>

On Wed, Aug 26, 1998 at 08:33:59PM +0400, Sergey Okhapkin wrote:
>Christopher Faylor wrote:
>> I've committed these changes (and the revision sent in subsequent email).
>>
>> Thank you for submitting them.
>>
>
>With these changes bash traps on starting a process when tty support is 
>enabled... Dup2 call forks unix_path_name_ pointer! What about to replace 
>this pointer with a static array?

I've actually fixed this in the experimental stuff that I've been working
on.

In the interim, does this solve the problem?

Index: ChangeLog
===================================================================
RCS file: /cvs/cvsfiles/devo/winsup/ChangeLog,v
retrieving revision 1.538
diff -u -p -r1.538 ChangeLog
--- ChangeLog	1998/08/26 16:19:46	1.538
+++ ChangeLog	1998/08/26 18:20:41
@@ -1,3 +1,11 @@
+Wed Aug 26 14:15:22 1998  Christopher Faylor <cgf AT cygnus DOT com>
+
+	* fhandler.h (fhandler_base): Make set_name() public and implement
+	clear_name() to accomodate dup2.
+	* hinfo.cc (dup2): Previous change exposed problem with dup2.
+	Same unix_path_name_ ptr was being used in two separate fds.
+	Fix this.
+
 Wed Aug 26 12:10:27 1998  Christopher Faylor <cgf AT cygnus DOT com>
 
 	patch from sos AT prospect DOT com DOT ru (Sergey Okhapkin):
Index: fhandler.h
===================================================================
RCS file: /cvs/cvsfiles/devo/winsup/fhandler.h,v
retrieving revision 1.53
diff -u -p -r1.53 fhandler.h
--- fhandler.h	1998/07/08 19:14:13	1.53
+++ fhandler.h	1998/08/26 18:20:41
@@ -73,8 +73,6 @@ class fhandler_base
   /* File open flags from open (void) and fcntl (void) calls */
   int openflags_;
 
-  void set_name (const char *);
-
 protected:
 
   char symlink_p_;
@@ -107,7 +105,10 @@ public:
   void set_close_on_exec (char val) { close_exec_p_ = val; }
   char get_close_on_exec (void) { return close_exec_p_; }
 
+  void clear_name () {unix_path_name_ = NULL; }
   const char *get_name (void) { return unix_path_name_; }
+  void set_name (const char *);
+
   unsigned long get_namehash (void) { return namehash_; }
 
   /* Potentially overridden virtual functions. */
Index: hinfo.cc
===================================================================
RCS file: /cvs/cvsfiles/devo/winsup/hinfo.cc,v
retrieving revision 1.52
diff -u -p -r1.52 hinfo.cc
--- hinfo.cc	1998/08/17 21:05:00	1.52
+++ hinfo.cc	1998/08/26 18:20:41
@@ -352,6 +352,8 @@ hinfo_vec::dup2 (int oldfd, int newfd)
   
   vec[newfd].h = (fhandler_base *) &vec[newfd].item;
   vec[newfd].item = vec[oldfd].item;
+  vec[newfd].h->clear_name ();
+  vec[newfd].h->set_name (vec[oldfd].h->get_name ());
   if (vec[oldfd].h->dup (vec[newfd].h) != 0)
     return -1;