Public bug reported: Qt is - at least in 11.04 and 12.04 - built with the -Bsymbolic- functions linker flag enabled which binds references to global function symbols to the definition within the shared library [1]. This is okay for most use-cases out there but breaks certain scenarios where preloading is involved.
Qt specifies certain dynamic-list files (see [2]) to enable dynamic binding for certain symbols. An example file is "QT_SOURCE/src/corelib/QtCore.dynlist". However, currently these files are not used since Qt's configure is not instructed with -reduce- relocations which would enable passing the --dynamic-list linker flag on compilation. Note that this is only relevant if built with -Bsymbolic- functions. In fact, -reduce-relocations both enable -Bsymbolic-functions and --dynamic-list parameters to be passed. Qt in 11.10 seems to be compiled without -Bsymbolic-function (checked build logs on Launchpad). [1] http://www.technovelty.org/code/c/bsymbolic-update.html [2] http://linux.die.net/man/1/ld ** Affects: qt4-x11 (Ubuntu) Importance: Undecided Status: New ** Description changed: Qt is - at least in 11.04 and 12.04 - built with the -Bsymbolic- functions linker flag enabled which binds references to global function symbols to the definition within the shared library [1]. This is okay for most use-cases out there but breaks certain scenarios where preloading is involved. Qt specifies certain dynamic-list files (see [2]) to enable dynamic binding for certain symbols. An example file is "QT_SOURCE/src/corelib/QtCore.dynlist". However, currently these files are not used since Qt's configure is not instructed with -reduce- relocations which would enable passing the --dynamic-list linker flag on - compilation. Not that this is only relevant if built with -Bsymbolic- + compilation. Note that this is only relevant if built with -Bsymbolic- functions. In fact, -reduce-relocations both enable -Bsymbolic-functions and --dynamic-list parameters to be passed. Qt in 11.10 seems to be compiled without -Bsymbolic-function (checked build logs on Launchpad). [1] http://www.technovelty.org/code/c/bsymbolic-update.html [2] http://linux.die.net/man/1/ld -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/906014 Title: Qt built with -Bsymbolic-functions, not using -reduce-relocations from configure To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/qt4-x11/+bug/906014/+subscriptions -- ubuntu-bugs mailing list [email protected] https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
