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, 59 deletions

diff --git a/sysdeps/unix/sysv/linux/tst-rseq.h b/sysdeps/unix/sysv/linux/tst-rseq.h
deleted file mode 100644
index c2cb211f56..0000000000
--- a/sysdeps/unix/sysv/linux/tst-rseq.h
+++ /dev/null
@@ -1,59 +0,0 @@
-/* Restartable Sequences tests header.
-   Copyright (C) 2020 Free Software Foundation, Inc.
-
-   The GNU C Library is free software; you can redistribute it and/or
-   modify it under the terms of the GNU Lesser General Public
-   License as published by the Free Software Foundation; either
-   version 2.1 of the License, or (at your option) any later version.
-
-   The GNU C Library is distributed in the hope that it will be useful,
-   but WITHOUT ANY WARRANTY; without even the implied warranty of
-   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
-   Lesser General Public License for more details.
-
-   You should have received a copy of the GNU Lesser General Public
-   License along with the GNU C Library; if not, see
-   <https://www.gnu.org/licenses/>.  */
-
-#include <errno.h>
-#include <error.h>
-#include <stdbool.h>
-#include <stdint.h>
-#include <support/check.h>
-#include <syscall.h>
-#include <sys/rseq.h>
-
-static inline bool
-rseq_thread_registered (void)
-{
-  int32_t v;
-
-  __atomic_load (&__rseq_abi.cpu_id, &v, __ATOMIC_RELAXED);
-  return v >= 0;
-}
-
-static inline int
-sys_rseq (struct rseq *rseq_abi, uint32_t rseq_len, int flags, uint32_t sig)
-{
-  return syscall (__NR_rseq, rseq_abi, rseq_len, flags, sig);
-}
-
-static inline bool
-rseq_available (void)
-{
-  int rc;
-
-  rc = sys_rseq (NULL, 0, 0, 0);
-  if (rc != -1)
-    FAIL_EXIT1 ("Unexpected rseq return value %d", rc);
-  switch (errno)
-    {
-    case ENOSYS:
-      return false;
-    case EINVAL:
-      /* rseq is implemented, but detected an invalid rseq_len parameter.  */
-      return true;
-    default:
-      FAIL_EXIT1 ("Unexpected rseq error %s", strerror (errno));
-    }
-}