145 lines
3.5 KiB
Bash
Executable File
145 lines
3.5 KiB
Bash
Executable File
#!/bin/sh
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#
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# SPDX-License-Identifier: BSD-2-Clause-FreeBSD
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#
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# Copyright (c) 2017 Konstantin Belousov <kib@FreeBSD.org>
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#
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# Redistribution and use in source and binary forms, with or without
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# modification, are permitted provided that the following conditions
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# are met:
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# 1. Redistributions of source code must retain the above copyright
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# notice, this list of conditions and the following disclaimer.
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# 2. Redistributions in binary form must reproduce the above copyright
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# notice, this list of conditions and the following disclaimer in the
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# documentation and/or other materials provided with the distribution.
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#
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# THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
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# ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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# ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
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# FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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# DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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# OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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# HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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# LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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# OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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# SUCH DAMAGE.
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#
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# Maxime Villard <max@m00nbsd.net> spotted this problem:
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# Issue with segment registers on freebsd-i386
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# Fixed in r323722
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[ `uname -m` = "i386" ] || exit 0
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. ../default.cfg
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cat > /tmp/mvillard_nest.c <<EOF
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/* $Id: mvillard_nest.c,v 1.2 2017/09/15 14:33:30 kostik Exp kostik $ */
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#include <sys/types.h>
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#include <sys/syscall.h>
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#include <sys/ucontext.h>
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#include <machine/atomic.h>
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#include <machine/segments.h>
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#include <machine/sysarch.h>
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#include <err.h>
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#include <pthread.h>
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#include <signal.h>
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#include <time.h>
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#include <string.h>
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#include <unistd.h>
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static volatile u_int b, s;
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static void *
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dealloc_ldt(void *arg __unused)
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{
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u_int sl;
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for (;;) {
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while (atomic_load_acq_int(&b) == 0)
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;
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sl = s;
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s = 0;
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if (sl != 0)
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i386_set_ldt(sl, NULL, 1);
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atomic_store_rel_int(&b, 0);
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}
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return (NULL);
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}
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static void
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func(void)
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{
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union descriptor desc;
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u_int sel, sl;
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bzero(&desc, sizeof(desc));
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desc.sd.sd_type = SDT_MEMRWA;
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desc.sd.sd_dpl = SEL_UPL;
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desc.sd.sd_p = 1;
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desc.sd.sd_def32 = 1;
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desc.sd.sd_gran = 1;
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desc.sd.sd_lolimit = 0xffff;
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desc.sd.sd_hilimit = 0xf;
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sl = i386_set_ldt(LDT_AUTO_ALLOC, &desc, 1);
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if ((int)sl == -1)
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err(1, "i386_set_ldt");
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sel = LSEL(sl, SEL_UPL);
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s = sl;
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__asm volatile("movw\t%w0,%%es" : : "r" (sel));
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atomic_store_rel_int(&b, 1);
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while (atomic_load_acq_int(&b) != 0)
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;
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getpid();
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}
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static void
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sigsegv_handler(int signo __unused, siginfo_t *si __unused, void *rctx)
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{
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ucontext_t *uc;
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uc = rctx;
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uc->uc_mcontext.mc_es = uc->uc_mcontext.mc_ds;
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}
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int
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main(void)
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{
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pthread_t thr;
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time_t start;
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struct sigaction sa;
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int error;
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bzero(&sa, sizeof(sa));
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sa.sa_sigaction = sigsegv_handler;
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sa.sa_flags = SA_SIGINFO;
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error = sigaction(SIGSEGV, &sa, NULL);
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if (error != 0)
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err(1, "sigaction SIGSEGV");
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error = sigaction(SIGBUS, &sa, NULL);
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if (error != 0)
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err(1, "sigaction SIGBUS");
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error = pthread_create(&thr, NULL, dealloc_ldt, NULL);
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if (error != 0)
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errc(1, error, "pthread_create");
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start = time(NULL);
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while (time(NULL) - start < 120)
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func();
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}
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EOF
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mycc -o /tmp/mvillard_nest -Wall -Wextra -O2 -g /tmp/mvillard_nest.c \
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-l pthread || exit 1
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rm /tmp/mvillard_nest.c
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/tmp/mvillard_nest; s=$?
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rm /tmp/mvillard_nest
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exit $s
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