On Sat, Apr 30, 2011 at 12:00:41PM +0200, Mike Hommey wrote: > On Thu, Apr 28, 2011 at 02:17:15PM +0200, Gabriel Paubert wrote: > > On Thu, Apr 28, 2011 at 12:10:54PM +0200, Mike Hommey wrote: > > > On Thu, Apr 28, 2011 at 12:04:42PM +0200, Mike Hommey wrote: > > > > Let me write it again: > > > > - The R_PPC_REL24 relocations are all over libxul.so on objects that are > > > > built -fPIC. > > > > - libcrmf.a is also linked into libxul.so, and it also contains > > > > R_PPC_REL24 relocations, but all the objects it contains are built > > > > -fPIC. > > > > > > And this is a -Os bug, apparently. Building with -O2 doesn't seem to > > > yield these relocations. > > > > That's because the out-of-line prologue/epilogue register save and > > restore functions are only used at -Os (they save size). > > > > Now I believe, but don't quote me on that, that the linker > > should insert a copy of these functions in every shared library > > since these functions have non standard linkage and probably > > would not survive crossing shared library boundaries. > > > > I can see a bug if the shared library text size is above > > 32M or so (needs several copies of these functions), but > > I don't think the libraries are that big. > > The linker actually normally does that, because it compiles with -lgcc, > which will link libgcc.a, which contains these functions. > > However, for some reason, in libxul.so case, gcc uses -shared-libgcc, > which I fail to see where it collects it from (thanks KiBi for the > verbose build, see below). > > OTOH, I still can't reproduce with a simple test case. The linker still > seems to do the right thing. Even if I use the same build flags. > I really don't know what makes the libxul.so case so special. Its size?
So, the problem is its compile line, containing -lstartup-notification-1, and has nothing to do with -shared-libgcc. It looks like startup-notification was built with a broken toolchain in 2009 (will ask for a binNMU), and exported the _rest* symbols that libgcc.a also contains. As -lstartup-notification-1 appears before -lgcc on the link line, ld wrongly picks the versions in startup-notification-1. So it looks to me like there were and are several problems: - The original problem that made startup-notification export these symbols, that is gone. - gcc, that doesn't mark _rest* symbols as hidden in object files (they are in libgcc.a) I guess fixing the latter would either force ld to use the libgcc.a symbols or fail to link with the startup-notification symbols. Mike -- To UNSUBSCRIBE, email to debian-powerpc-requ...@lists.debian.org with a subject of "unsubscribe". Trouble? Contact listmas...@lists.debian.org Archive: http://lists.debian.org/20110430180457.ga9...@glandium.org
