Re: Hanging conftest

[Eric Blake <eblake at redhat dot com>]

On 11/28/2013 06:54 AM, Eric Blake wrote:
> On 11/27/2013 10:00 PM, Siddhesh Poyarekar wrote:
> 
>>>> checking for working re_compile_pattern... 
>>>>
>>>> When the configure script hang and didn't continue.
> 
>> workaround, you could export MALLOC_CHECK_ to 2 so that the program
>> only aborts and does not try to print a backtrace.
> 
> Michal, since you have the environment to test this, can you rerun:
> 
> ./configure MALLOC_CHECK_=2
> 
> and see if the hang goes away?  If so, then I know how to patch gnulib
> to ensure that this particular environment variable is always set for
> each conftest that tries to tickle a known glibc memory corruption bug.

On IRC, Michal confirmed that this hack patch helped avoid a conftest hang:

diff --git i/m4/regex.m4 w/m4/regex.m4
index 424ae33..b0eed19 100644
--- i/m4/regex.m4
+++ w/m4/regex.m4
 -41,6 +41,15 @@ AC_DEFUN([gl_REGEX],
             # include <unistd.h>
             # include <signal.h>
             #endif
+#ifdef __linux__
+#include <execinfo.h>
+static void __attribute__ ((constructor))
+init_backtrace()
+{
+   void *bt[10];
+   backtrace (bt, 10);
+}
+#endif
           ]],
           [[int result = 0;
             static struct re_pattern_buffer regex;

But then he reported that the check for a working sleep() hung, which
makes me wonder if SIGALRM/alarm() semantics are broken on his system.

-- 
Eric Blake   eblake redhat com    +1-919-301-3266
Libvirt virtualization library http://libvirt.org

Attachment: signature.asc
Description: OpenPGP digital signature