107 lines
3.4 KiB
C
107 lines
3.4 KiB
C
/*-
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* SPDX-License-Identifier: BSD-2-Clause
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*
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* Copyright (c) 2003 Marcel Moolenaar
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* All rights reserved.
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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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*
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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 ``AS IS'' AND ANY EXPRESS OR
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* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
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* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
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* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
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* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
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* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
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* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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*/
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#include <sys/cdefs.h>
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#include <sys/types.h>
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#include <sys/ucontext.h>
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#include <signal.h>
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#include <stdlib.h>
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#include <strings.h>
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typedef void (*handler_t)(uint64_t, uint64_t, uint64_t);
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/* Prototypes */
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static void sigctx_wrapper(ucontext_t *ucp, handler_t func, uint64_t *args);
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__weak_reference(__signalcontext, signalcontext);
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int
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__signalcontext(ucontext_t *ucp, int sig, __sighandler_t *func)
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{
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uint64_t *args;
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siginfo_t *sig_si;
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ucontext_t *sig_uc;
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uint64_t sp;
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/* Bail out if we don't have a valid ucontext pointer. */
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if (ucp == NULL)
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abort();
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/*
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* Build a signal frame and copy the arguments of signal handler
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* 'func' onto the stack and do the funky stack alignment.
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* This means that we need an 8-byte-odd alignment since the ABI expects
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* the return address to be pushed, thus breaking the 16 byte alignment.
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*/
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sp = (ucp->uc_mcontext.mc_rsp - 128 - sizeof(ucontext_t)) & ~15UL;
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sig_uc = (ucontext_t *)sp;
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bcopy(ucp, sig_uc, sizeof(*sig_uc));
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sp = (sp - sizeof(siginfo_t)) & ~15UL;
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sig_si = (siginfo_t *)sp;
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bzero(sig_si, sizeof(*sig_si));
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sig_si->si_signo = sig;
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sp -= 3 * sizeof(uint64_t);
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args = (uint64_t *)sp;
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args[0] = sig;
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args[1] = (intptr_t)sig_si;
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args[2] = (intptr_t)sig_uc;
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sp -= 16;
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/*
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* Setup the ucontext of the signal handler.
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*/
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bzero(&ucp->uc_mcontext, sizeof(ucp->uc_mcontext));
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ucp->uc_mcontext.mc_fpformat = _MC_FPFMT_NODEV;
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ucp->uc_mcontext.mc_ownedfp = _MC_FPOWNED_NONE;
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ucp->uc_link = sig_uc;
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sigdelset(&ucp->uc_sigmask, sig);
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ucp->uc_mcontext.mc_len = sizeof(mcontext_t);
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ucp->uc_mcontext.mc_rdi = (register_t)ucp;
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ucp->uc_mcontext.mc_rsi = (register_t)func;
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ucp->uc_mcontext.mc_rdx = (register_t)args;
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ucp->uc_mcontext.mc_rbp = (register_t)sp;
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ucp->uc_mcontext.mc_rbx = (register_t)sp;
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ucp->uc_mcontext.mc_rsp = (register_t)sp;
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ucp->uc_mcontext.mc_rip = (register_t)sigctx_wrapper;
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return (0);
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}
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static void
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sigctx_wrapper(ucontext_t *ucp, handler_t func, uint64_t *args)
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{
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(*func)(args[0], args[1], args[2]);
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if (ucp->uc_link == NULL)
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exit(0);
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setcontext((const ucontext_t *)ucp->uc_link);
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/* should never get here */
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abort();
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/* NOTREACHED */
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}
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