Linux: Remove rseq support

The kernel ABI is not finalized, and there are now various proposals
to change the size of struct rseq, which would make the glibc ABI
dependent on the version of the kernels used for building glibc.
This is of course not acceptable.

This reverts commit 48699da1c468543ade14777819bd1b4d652709de ("elf:
Support at least 32-byte alignment in static dlopen"), commit
8f4632deb3545b2949cec5454afc3cb21a0024ea ("Linux: rseq registration
tests"), commit 6e29cb3f61ff5432c78a1c84b0d9b123a350ab36 ("Linux: Use
rseq in sched_getcpu if available"), and commit
0c76fc3c2b346dc5401dc055d97d4279632b0fb3 ("Linux: Perform rseq
registration at C startup and thread creation"), resolving the conflicts
introduced by the ARC port and the TLS static surplus changes.

Reviewed-by: Carlos O'Donell <carlos@redhat.com>

1 files changed, 0 insertions, 10 deletions

diff --git a/NEWS b/NEWS
index 5051e804ea..1ef4a0a7a4 100644
--- a/NEWS
+++ b/NEWS
@@ -42,16 +42,6 @@ Major new features:
   pthread_attr_getsigmask_np have been added.  They allow applications
   to specify the signal mask of a thread created with pthread_create.
 
-* Support for automatically registering threads with the Linux rseq
-  system call has been added.  This system call is implemented starting
-  from Linux 4.18.  The Restartable Sequences ABI accelerates user-space
-  operations on per-cpu data.  It allows user-space to perform updates
-  on per-cpu data without requiring heavy-weight atomic operations.
-  Automatically registering threads allows all libraries, including libc,
-  to make immediate use of the rseq support by using the documented ABI.
-  The GNU C Library manual has details on integration of Restartable
-  Sequences.
-
 * The GNU C Library now provides the header file <sys/single_threaded.h>
   which declares the variable __libc_single_threaded.  Applications are
   encouraged to use this variable for single-thread optimizations,