Core dump on 32-bit Cygwin if program calls dlopen

Wed Jul 16 07:02:00 GMT 2014

Hi JonY,
On Jul 15 16:39, Corinna Vinschen wrote:
> On Jul 15 21:55, JonY wrote:
> > On 7/15/2014 21:08, Corinna Vinschen wrote:
> > >>
> > >> FWIW, the problem disappears if I revert gcc-core and libgcc1 to 4.8.2-2.
> > > 
> > > JonY, do you have a chance to have a look into this issue?
> > > 
> > 
> > Sorry, I have been busy these few weeks, but I am well aware that there
> > is a problem with one of the libgcc changes, but has yet to investigate it.
> > 
> > I believe Jon Turney has looked into it somewhat.
>> Sounds good. Thanks in advance.

Yesterday I asked my collegues to take a stab at the issue and one of
them, DJ Delorie, came up with a libgcc patch already. It hasn't been
sent upstream yet. Can we give it a try, perhaps by creating a new
libgcc DLL, please?
Thanks,
Corinna
Index: libgcc/config/i386/cygming-crtbegin.c
===================================================================

--- libgcc/config/i386/cygming-crtbegin.c	(revision 212546)
+++ libgcc/config/i386/cygming-crtbegin.c	(working copy)
@@ -99,12 +99,13 @@ static EH_FRAME_SECTION_CONST char __EH_
 = { };
 
 static struct object obj;
 
 /* Handle of libgcc's DLL reference. */
 HANDLE hmod_libgcc;
+static void * (*deregister_frame_fn) (const void *) = NULL;
 #endif
 
 #if TARGET_USE_JCR_SECTION
 static void *__JCR_LIST__[]
 __attribute__ ((used, section(JCR_SECTION_NAME), aligned(4)))
 = { };
@@ -130,15 +131,20 @@ __gcc_register_frame (void)
 if (h)
 {
 /* Increasing the load-count of LIBGCC_SONAME DLL. */
 hmod_libgcc = LoadLibrary (LIBGCC_SONAME);
 register_frame_fn = (void (*) (const void *, struct object *))
 			 GetProcAddress (h, "__register_frame_info");
+ deregister_frame_fn = (void* (*) (const void *))
+	 GetProcAddress (h, "__deregister_frame_info");
+ }
+ else
+ {
+ register_frame_fn = __register_frame_info;
+ deregister_frame_fn = __deregister_frame_info;
 }
- else 
- register_frame_fn = __register_frame_info;
 if (register_frame_fn)
 register_frame_fn (__EH_FRAME_BEGIN__, &obj);
 #endif
 
 #if TARGET_USE_JCR_SECTION 
 if (__JCR_LIST__[0])
@@ -158,19 +164,12 @@ __gcc_register_frame (void)
 }
 
 void
 __gcc_deregister_frame (void)
 {
 #if DWARF2_UNWIND_INFO
- void * (*deregister_frame_fn) (const void *);
- HANDLE h = GetModuleHandle (LIBGCC_SONAME);
- if (h)
- deregister_frame_fn = (void* (*) (const void *))
-			 GetProcAddress (h, "__deregister_frame_info");
- else 
- deregister_frame_fn = __deregister_frame_info;
 if (deregister_frame_fn)
 deregister_frame_fn (__EH_FRAME_BEGIN__);
 if (hmod_libgcc)
 FreeLibrary (hmod_libgcc);
 #endif
 }
-- 
Corinna Vinschen Please, send mails regarding Cygwin to
Cygwin Maintainer cygwin AT cygwin DOT com
Red Hat
-------------- next part --------------
A non-text attachment was scrubbed...
Name: not available
Type: application/pgp-signature
Size: 819 bytes
Desc: not available
URL: <http://cygwin.com/pipermail/cygwin/attachments/20140716/8bfaffe9/attachment.sig>
