Created attachment 130585 A hack to remove an optimization that is thread unsafe
Originally posted here: https://bugs.launchpad.net/ubuntu/+source/libx11/+bug/1062534 by Alessandro Pignotti -- You received this bug notification because you are a member of Ubuntu Touch seeded packages, which is subscribed to libx11 in Ubuntu. https://bugs.launchpad.net/bugs/1062534 Title: Thread unsafe access to internal linked list, breaks Origin games in Wine Status in xlibs: Unknown Status in libx11 package in Ubuntu: Triaged Bug description: In file src/xlibi18n/lcConv.c the following linked list head is defined static XlcConverterList conv_list = NULL; Which is then modified by _XlcSetConverter and get_converter in a non thread-safe manner. Inside get_converter the list is reorderder to increase the efficiency of looking up the same element the next time, but this is especially dangerous since a seemingly read-only method is actually modifying the data. Modifying the list in such thread unsafe manner does case the list to become garbled in some workloads and causes infinite loops when the get_converter is invoked. The solution I suggest is to add a mutex or spinlock around accesses to the linked list, I would it myself but I'm not sure about what is the usual mutex implementation for this project. To manage notifications about this bug go to: https://bugs.launchpad.net/xlibs/+bug/1062534/+subscriptions -- Mailing list: https://launchpad.net/~touch-packages Post to : touch-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~touch-packages More help : https://help.launchpad.net/ListHelp
