----- On Jan 14, 2019, at 10:55 AM, Florian Weimer fweimer@xxxxxxxxxx wrote: > * Mathieu Desnoyers: > >> Therefore, both symbols will end up in >> sysdeps/unix/sysv/linux/Versions. > > I'm not sure what you mean by that. The physical location in the > directory tree has little effect on which shared object the symbol is > placed in; that will need other changes. I'm currently moving the symbol definitions to csu/rseq-sym.c. On Linux, its content is overridden by a new sysdeps/unix/sysv/linux/rseq-sym.c which contains both __rseq_abi and __rseq_refcount symbols. On other platforms, it is a stub file. >>> By the way, you could avoid the need for unregistration if you allocated >>> the rseq areas persistently, index by TID. They are quite small, so >>> with the typical PID range, maybe the wasted memory due to changing TIDs >>> would be acceptable? >> >> Would we be able to access those __rseq_abi as normal TLS IE model >> variables ? The overhead of indexing an array matters for a >> fast-path. > > No, that wouldn't be possible in this case. You would need another > indirection. Thanks for the clarification! Mathieu -- Mathieu Desnoyers EfficiOS Inc. http://www.efficios.com
