From c901c3e764d7c7079f006b4e21e877d5036eb4f5 Mon Sep 17 00:00:00 2001 From: Florian Weimer Date: Thu, 9 Dec 2021 09:49:32 +0100 Subject: nptl: Add public rseq symbols and The relationship between the thread pointer and the rseq area is made explicit. The constant offset can be used by JIT compilers to optimize rseq access (e.g., for really fast sched_getcpu). Extensibility is provided through __rseq_size and __rseq_flags. (In the future, the kernel could request a different rseq size via the auxiliary vector.) Co-Authored-By: Mathieu Desnoyers Reviewed-by: Szabolcs Nagy --- sysdeps/unix/sysv/linux/sys/rseq.h | 10 ++++++++++ 1 file changed, 10 insertions(+) (limited to 'sysdeps/unix/sysv/linux/sys') diff --git a/sysdeps/unix/sysv/linux/sys/rseq.h b/sysdeps/unix/sysv/linux/sys/rseq.h index c8edff5..1215b5d 100644 --- a/sysdeps/unix/sysv/linux/sys/rseq.h +++ b/sysdeps/unix/sysv/linux/sys/rseq.h @@ -171,4 +171,14 @@ struct rseq #endif /* __GLIBC_HAVE_KERNEL_RSEQ */ +/* Offset from the thread pointer to the rseq area. */ +extern const int __rseq_offset; + +/* Size of the registered rseq area. 0 if the registration was + unsuccessful. */ +extern const unsigned int __rseq_size; + +/* Flags used during rseq registration. */ +extern const unsigned int __rseq_flags; + #endif /* sys/rseq.h */ -- cgit v1.1