* Mathieu Desnoyers: > Register rseq(2) TLS for each thread (including main), and unregister > for each thread (excluding main). "rseq" stands for Restartable > Sequences. > > See the rseq(2) man page proposed here: > https://lkml.org/lkml/2018/9/19/647 > > This patch is based on glibc-2.30. The rseq(2) system call was merged > into Linux 4.18. This patch needs to be updated for some be/le abilist splits. Big-endian ABI lists for arm, microblaze, sh, appear to be missing. This is something that can be checked with build-many-glibcs.py. > diff --git a/manual/threads.texi b/manual/threads.texi > index 0858ef8f92..059f781120 100644 > --- a/manual/threads.texi > +++ b/manual/threads.texi > @@ -881,3 +881,20 @@ Behaves like @code{pthread_timedjoin_np} except that the absolute time in > @c pthread_spin_unlock > @c pthread_testcancel > @c pthread_yield > + > +@node Restartable Sequences > +@section Restartable Sequences > +@cindex rseq > + > +This section describes the @glibcadj{} Restartable Sequences integration. > + > +The @glibcadj{} implements a __rseq_abi TLS symbol to interact with the @Theglibc{} @code{__rseq_abi} > +Restartable Sequences system call (Linux-specific). The layout of this > +structure is defined by the Linux kernel rseq.h UAPI. Registration of each > +thread's __rseq_abi is performed by @glibcadj{} at libc initialization and @theglibc{} @code{__rseq_abi} > +pthread creation. > +Each supported architecture provide a RSEQ_SIG signature in sys/rseq.h. That @code{RSEQ_SIG} @file{sys/rseq.h} > +signature is expected to be present in the code before each Restartable > +Sequences abort handler. Failure to provide the expected signature may > +terminate the process with a Segmentation fault. Two spaces at the end of setences, please. The manual should use @deftypevar to create an index entry etc. for __rseq_abi. See argp_program_version for an example of how to do this. I think current policy is to have documentation for at least the minimum functionality in the manual. I understand that it makes it a lot of work to write patches which add system call wrappers. Thanks, Florian
