On 09/03/09 22:06, Tejun Heo wrote: >>> Heh... here's a naive and hopeful plan. How about we beg gcc >>> developers to allow different segment register and offset in newer gcc >>> versions and then use the same one when building with the new gcc? >>> This should solve the i386 problem too. It would be the best as we >>> get to keep the separate segment register from the userland. Too >>> hopeful? >>> >> I think it's possible to set the register in more recent gcc. Doing the >> sane thing and having a symbol for an offset is probably worse. >> > I was thinking about altering the build process so that we can use sed > to substitute %gs:40 with %fs:40 while compiling. If it's already > possible to override the register in more recent gcc, no need to go > into that horror. > Ideally we'd like to get rid of the constant offset too. If we could change it to %[fg]s:__gcc_stack_canary_offset on both 32-bit and 64-bit, it would give us a lot more flexibility. __gcc_stack_canary_offset could be weakly defined to 20/40 for backwards compatibility, but we could override it to point to a normal percpu variable. J -- To unsubscribe from this list: send the line "unsubscribe linux-tip-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html