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, 256 deletions

diff --git a/sysdeps/unix/sysv/linux/tst-rseq-nptl.c b/sysdeps/unix/sysv/linux/tst-rseq-nptl.c
deleted file mode 100644
index 5e788dc..0000000
--- a/sysdeps/unix/sysv/linux/tst-rseq-nptl.c
+++ /dev/null
@@ -1,256 +0,0 @@
-/* Restartable Sequences NPTL test.
-   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/>.  */
-
-/* These tests validate that rseq is registered from various execution
-   contexts (main thread, destructor, other threads, other threads created
-   from destructor, forked process (without exec), pthread_atfork handlers,
-   pthread setspecific destructors, signal handlers, atexit handlers).
-
-   See the Linux kernel selftests for extensive rseq stress-tests.  */
-
-#include <stdio.h>
-#include <support/check.h>
-#include <support/xthread.h>
-#include <sys/rseq.h>
-#include <unistd.h>
-
-#ifdef RSEQ_SIG
-# include <array_length.h>
-# include <errno.h>
-# include <error.h>
-# include <pthread.h>
-# include <signal.h>
-# include <stdlib.h>
-# include <string.h>
-# include <support/namespace.h>
-# include <support/xsignal.h>
-# include <syscall.h>
-# include <sys/types.h>
-# include <sys/wait.h>
-# include "tst-rseq.h"
-
-static pthread_key_t rseq_test_key;
-
-static void
-atfork_prepare (void)
-{
-  if (!rseq_thread_registered ())
-    {
-      printf ("error: rseq not registered in pthread atfork prepare\n");
-      support_record_failure ();
-    }
-}
-
-static void
-atfork_parent (void)
-{
-  if (!rseq_thread_registered ())
-    {
-      printf ("error: rseq not registered in pthread atfork parent\n");
-      support_record_failure ();
-    }
-}
-
-static void
-atfork_child (void)
-{
-  if (!rseq_thread_registered ())
-    {
-      printf ("error: rseq not registered in pthread atfork child\n");
-      support_record_failure ();
-    }
-}
-
-static void
-rseq_key_destructor (void *arg)
-{
-  /* Cannot use deferred failure reporting after main returns.  */
-  if (!rseq_thread_registered ())
-    FAIL_EXIT1 ("rseq not registered in pthread key destructor");
-}
-
-static void
-atexit_handler (void)
-{
-  /* Cannot use deferred failure reporting after main returns.  */
-  if (!rseq_thread_registered ())
-    FAIL_EXIT1 ("rseq not registered in atexit handler");
-}
-
-static void
-do_rseq_main_test (void)
-{
-  TEST_COMPARE (atexit (atexit_handler), 0);
-  rseq_test_key = xpthread_key_create (rseq_key_destructor);
-  TEST_COMPARE (pthread_atfork (atfork_prepare, atfork_parent, atfork_child), 0);
-  xraise (SIGUSR1);
-  TEST_COMPARE (pthread_setspecific (rseq_test_key, (void *) 1l), 0);
-  TEST_VERIFY_EXIT (rseq_thread_registered ());
-}
-
-static void
-cancel_routine (void *arg)
-{
-  if (!rseq_thread_registered ())
-    {
-      printf ("error: rseq not registered in cancel routine\n");
-      support_record_failure ();
-    }
-}
-
-static pthread_barrier_t cancel_thread_barrier;
-static pthread_cond_t cancel_thread_cond = PTHREAD_COND_INITIALIZER;
-static pthread_mutex_t cancel_thread_mutex = PTHREAD_MUTEX_INITIALIZER;
-
-static void
-test_cancel_thread (void)
-{
-  pthread_cleanup_push (cancel_routine, NULL);
-  (void) xpthread_barrier_wait (&cancel_thread_barrier);
-  /* Wait forever until cancellation.  */
-  xpthread_cond_wait (&cancel_thread_cond, &cancel_thread_mutex);
-  pthread_cleanup_pop (0);
-}
-
-static void *
-thread_function (void * arg)
-{
-  int i = (int) (intptr_t) arg;
-
-  xraise (SIGUSR1);
-  if (i == 0)
-    test_cancel_thread ();
-  TEST_COMPARE (pthread_setspecific (rseq_test_key, (void *) 1l), 0);
-  return rseq_thread_registered () ? NULL : (void *) 1l;
-}
-
-static void
-sighandler (int sig)
-{
-  if (!rseq_thread_registered ())
-    {
-      printf ("error: rseq not registered in signal handler\n");
-      support_record_failure ();
-    }
-}
-
-static void
-setup_signals (void)
-{
-  struct sigaction sa;
-
-  sigemptyset (&sa.sa_mask);
-  sigaddset (&sa.sa_mask, SIGUSR1);
-  sa.sa_flags = 0;
-  sa.sa_handler = sighandler;
-  xsigaction (SIGUSR1, &sa, NULL);
-}
-
-static int
-do_rseq_threads_test (int nr_threads)
-{
-  pthread_t th[nr_threads];
-  int i;
-  int result = 0;
-
-  xpthread_barrier_init (&cancel_thread_barrier, NULL, 2);
-
-  for (i = 0; i < nr_threads; ++i)
-    th[i] = xpthread_create (NULL, thread_function,
-                             (void *) (intptr_t) i);
-
-  (void) xpthread_barrier_wait (&cancel_thread_barrier);
-
-  xpthread_cancel (th[0]);
-
-  for (i = 0; i < nr_threads; ++i)
-    {
-      void *v;
-
-      v = xpthread_join (th[i]);
-      if (i != 0 && v != NULL)
-        {
-          printf ("error: join %d successful, but child failed\n", i);
-          result = 1;
-        }
-      else if (i == 0 && v == NULL)
-        {
-          printf ("error: join %d successful, child did not fail as expected\n", i);
-          result = 1;
-        }
-    }
-
-  xpthread_barrier_destroy (&cancel_thread_barrier);
-
-  return result;
-}
-
-static void
-subprocess_callback (void *closure)
-{
-  do_rseq_main_test ();
-}
-
-static void
-do_rseq_fork_test (void)
-{
-  support_isolate_in_subprocess (subprocess_callback, NULL);
-}
-
-static int
-do_rseq_test (void)
-{
-  int t[] = { 1, 2, 6, 5, 4, 3, 50 };
-  int i, result = 0;
-
-  if (!rseq_available ())
-    FAIL_UNSUPPORTED ("kernel does not support rseq, skipping test");
-  setup_signals ();
-  xraise (SIGUSR1);
-  do_rseq_main_test ();
-  for (i = 0; i < array_length (t); i++)
-    if (do_rseq_threads_test (t[i]))
-      result = 1;
-  do_rseq_fork_test ();
-  return result;
-}
-
-static void __attribute__ ((destructor))
-do_rseq_destructor_test (void)
-{
-  /* Cannot use deferred failure reporting after main returns.  */
-  if (do_rseq_test ())
-    FAIL_EXIT1 ("rseq not registered within destructor");
-  xpthread_key_delete (rseq_test_key);
-}
-
-#else /* RSEQ_SIG */
-static int
-do_rseq_test (void)
-{
-  FAIL_UNSUPPORTED ("glibc does not define RSEQ_SIG, skipping test");
-  return 0;
-}
-#endif /* RSEQ_SIG */
-
-static int
-do_test (void)
-{
-  return do_rseq_test ();
-}
-
-#include <support/test-driver.c>