On 02/14/2014 09:23 AM, Alexander Monakov wrote: > > On Fri, 14 Feb 2014, Paul Woegerer wrote: > >> As explained by Alexander Monakov, dlsym() is defined to be pure, thus the >> compiler is allowed to assume that there is no need to write the changes >> performed by setup_static_allocator() into memory prior to calling dlsym(). >> The added cmm_barrier() forces the compiler to write the changes into memory. >> >> For more details refer to: >> http://lists.lttng.org/pipermail/lttng-dev/2014-February/022389.html > If everyone here agrees that this is a workaround for a glibc bug, please add > a note to that effect in the patch and please notify glibc upstream (again).
I'v just submitted https://sourceware.org/bugzilla/show_bug.cgi?id=16585 > FWIW, when toying with a similar code I implemented a different workaround > along the lines of > > #define dlsym glibc_dlsym_proto_lies_about_leafness > #include <dlfcn.h> > #undef dlsym > > extern void *dlsym(void *, const char *); > > > Thus avoiding the need to sprinkle unneeded compiler memory barriers in code. Right, this looks very clean indeed. Stefan -- Stefan Seefeld CodeSourcery / Mentor Graphics http://www.mentor.com/embedded-software/ _______________________________________________ lttng-dev mailing list [email protected] http://lists.lttng.org/cgi-bin/mailman/listinfo/lttng-dev
