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93d0bfbe8f
Move the rseq area to the newly added 'extra TLS' block, this is the last step in adding support for the rseq extended ABI. The size of the rseq area is now dynamic and depends on the rseq features reported by the kernel through the elf auxiliary vector. This will allow applications to use rseq features past the 32 bytes of the original rseq ABI as they become available in future kernels. Signed-off-by: Michael Jeanson <mjeanson@efficios.com> Reviewed-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Reviewed-by: Florian Weimer <fweimer@redhat.com>
42 lines
1.3 KiB
C
42 lines
1.3 KiB
C
/* Copyright (C) 2007-2025 Free Software Foundation, Inc.
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This file is part of the GNU C Library.
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The GNU C Library is free software; you can redistribute it and/or
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modify it under the terms of the GNU Lesser General Public
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License as published by the Free Software Foundation; either
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version 2.1 of the License, or (at your option) any later version.
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The GNU C Library is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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Lesser General Public License for more details.
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You should have received a copy of the GNU Lesser General Public
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License along with the GNU C Library; if not, see
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<https://www.gnu.org/licenses/>. */
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#include <errno.h>
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#include <sched.h>
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#include <sysdep.h>
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#include <sysdep-vdso.h>
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#include <rseq-internal.h>
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static int
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vsyscall_sched_getcpu (void)
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{
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unsigned int cpu;
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int r = -1;
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#ifdef HAVE_GETCPU_VSYSCALL
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r = INLINE_VSYSCALL (getcpu, 3, &cpu, NULL, NULL);
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#else
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r = INLINE_SYSCALL_CALL (getcpu, &cpu, NULL, NULL);
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#endif
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return r == -1 ? r : cpu;
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}
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int
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sched_getcpu (void)
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{
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int cpu_id = RSEQ_GETMEM_ONCE (cpu_id);
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return __glibc_likely (cpu_id >= 0) ? cpu_id : vsyscall_sched_getcpu ();
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}
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