----- On Jan 14, 2019, at 2:37 PM, Florian Weimer fweimer@xxxxxxxxxx wrote: > * Mathieu Desnoyers: > >> ----- 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. > > You don't need a stub file if you use the “ifeq ($(subdir),csu)” > construct. OK > > The other question is whether this belongs into the csu subdirectory. > Since TLS is not available in ld.so, the initialization would have to > happen rather late, after relocation, but before ELF constructors are > run. > > (A side effect is that the rseq area would not be usable from IFUNC > resolvers.) Do you have a specific directory location in mind where we should put the built object ? e.g. "ifeq ($(subdir),posix)" or "ifeq ($(subdir),misc)" ? Moreover, from where should we call the rseq initialization ? I'm having trouble with invalid system calls parameters if I place it in LIBC_START_MAIN() just before or after the call to __pthread_initialize_minimal. I get what appears to be invalid parameters to sys_rseq, possibly due to stack corruption (?). I'm investigating at the moment. But if you prefer we call the rseq init from elsewhere, please let me know. Thanks, Mathieu -- Mathieu Desnoyers EfficiOS Inc. http://www.efficios.com
