glibc/sysdeps/unix/sysv/linux/tst-rseq.h
Michael Jeanson c813c1490d nptl: Add rseq auxvals
Get the rseq feature size and alignment requirement from the auxiliary
vector for use inside the dynamic loader. Use '__rseq_size' directly to
store the feature size. If the main thread registration fails or is
disabled by tunable, reset the value to 0.

This will be used in the TLS block allocator to compute the size and
alignment of the rseq area block for the extended ABI support.

Signed-off-by: Michael Jeanson <mjeanson@efficios.com>
Reviewed-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Reviewed-by: Florian Weimer <fweimer@redhat.com>
2025-01-10 20:19:07 +00:00

58 lines
1.6 KiB
C

/* Restartable Sequences tests header.
Copyright (C) 2021-2025 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>
#include <tls.h>
#include <rseq-internal.h>
static inline bool
rseq_thread_registered (void)
{
return THREAD_GETMEM_VOLATILE (THREAD_SELF, rseq_area.cpu_id) >= 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));
}
}