Crash due to missing synchronization on 'gconf_client' in 'jdk/src/solaris/native/sun/net/spi/DefaultProxySelector.c'

[David Holmes]

Hi Christian,

Probably best to discuss this on the net-dev at openjdk.java.net list (cc'd).

Two comments from me (I'm not on net-dev):

1. CHECK_NULL does a return so you will be leaving the monitor locked if 
you encounter any nulls.

2. Is it simpler to add synchronization at the Java level? (I don't know 
how this code is used)

David Holmes

On 2/08/2012 8:54 PM, Christian Schulte wrote:
> Hi,
>
> using the system property 'java.net.useSystemProxies', JDK 7 crashes on
> OpenBSD 5.2.
>
> $ /usr/local/jre-1.7.0/bin/java -version
> openjdk version "1.7.0_03"
> OpenJDK Runtime Environment (build 1.7.0_03-b04)
> OpenJDK Server VM (build 22.1-b02, mixed mode)
>
> $ /usr/local/jre-1.7.0/bin/java -cp . Crash
> 2538: assertion failed "allocator->lock_loc == NULL" file
> "/usr/ports/pobj/dbus-1.6.2/dbus-1.6.2/dbus/dbus-dataslot.c" line 79
> function _dbus_data_slot_allocator_alloc
> 2538: assertion failed "allocator->lock_loc == NULL" file
> "/usr/ports/pobj/dbus-1.6.2/dbus-1.6.2/dbus/dbus-dataslot.c" line 79
> function _dbus_data_slot_allocator_alloc
> 2538: assertion failed "allocator->lock_loc == NULL" file
> "/usr/ports/pobj/dbus-1.6.2/dbus-1.6.2/dbus/dbus-dataslot.c" line 79
> function _dbus_data_slot_allocator_alloc
> 2538: assertion failed "allocator->lock_loc == NULL" file
> "/usr/ports/pobj/dbus-1.6.2/dbus-1.6.2/dbus/dbus-dataslot.c" line 79
> function _dbus_data_slot_allocator_alloc
> D-Bus not compiled with backtrace support so unable to print a backtrace
> D-Bus not compiled with backtrace support so unable to print a backtrace
>
> $ /usr/local/jre-1.7.0/bin/java -cp . Crash
> 27421: assertion failed "!(connection)->have_connection_lock" file
> "/usr/ports/pobj/dbus-1.6.2/dbus-1.6.2/dbus/dbus-connection.c" line 1133
> function _dbus_connection_acquire_io_path
> D-Bus not compiled with backtrace support so unable to print a backtrace
> Abort trap (core dumped)
>
> Looking at
> 'openjdk/jdk/src/solaris/native/sun/net/spi/DefaultProxySelector.c',
> there is a 'static void* gconf_client' which is initialized by calling
> 'gconf_client_get_default' from 'libgconf-2'. Uses of that client are
> not protected against concurrent accesses by multiple threads although
> that gconf client is not thread-safe. Trying to add some protection
> myself resulted in the attached patch. Rebuilding JDK 1.7 with this
> patch applied, the 'gconf'/'dbus' related crashes no longer happen.
>
> Regards,
>