453 lines
13 KiB
C
453 lines
13 KiB
C
/*-
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* Copyright (c) 1994-1996 Søren Schmidt
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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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* 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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* in this position and unchanged.
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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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* 3. The name of the author may not be used to endorse or promote products
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* derived from this software withough specific prior written permission
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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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* $Id: linux_sysvec.c,v 1.31 1998/07/29 16:43:00 bde Exp $
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*/
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/* XXX we use functions that might not exist. */
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#include "opt_compat.h"
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#ifndef COMPAT_43
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#error "Unable to compile Linux-emulator due to missing COMPAT_43 option!"
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#endif
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#include <sys/param.h>
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#include <sys/buf.h>
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#include <sys/proc.h>
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#include <sys/systm.h>
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#include <sys/sysent.h>
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#include <sys/imgact.h>
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#include <sys/imgact_elf.h>
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#include <sys/signalvar.h>
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#include <sys/malloc.h>
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#include <vm/vm.h>
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#include <vm/vm_param.h>
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#include <vm/vm_prot.h>
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#include <vm/vm_page.h>
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#include <vm/vm_extern.h>
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#include <sys/exec.h>
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#include <sys/kernel.h>
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#include <machine/cpu.h>
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#include <i386/linux/linux.h>
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#include <i386/linux/linux_proto.h>
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static int linux_fixup __P((long **stack_base,
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struct image_params *iparams));
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static int elf_linux_fixup __P((long **stack_base,
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struct image_params *iparams));
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static void linux_prepsyscall __P((struct trapframe *tf, int *args,
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u_int *code, caddr_t *params));
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static void linux_sendsig __P((sig_t catcher, int sig, int mask,
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u_long code));
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/*
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* Linux syscalls return negative errno's, we do positive and map them
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*/
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static int bsd_to_linux_errno[ELAST] = {
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-0, -1, -2, -3, -4, -5, -6, -7, -8, -9,
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-10, -35, -12, -13, -14, -15, -16, -17, -18, -19,
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-20, -21, -22, -23, -24, -25, -26, -27, -28, -29,
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-30, -31, -32, -33, -34, -11,-115,-114, -88, -89,
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-90, -91, -92, -93, -94, -95, -96, -97, -98, -99,
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-100,-101,-102,-103,-104,-105,-106,-107,-108,-109,
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-110,-111, -40, -36,-112,-113, -39, -11, -87,-122,
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-116, -66, -6, -6, -6, -6, -6, -37, -38, -9,
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-6, -43, -42
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};
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int bsd_to_linux_signal[NSIG] = {
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0, LINUX_SIGHUP, LINUX_SIGINT, LINUX_SIGQUIT,
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LINUX_SIGILL, LINUX_SIGTRAP, LINUX_SIGABRT, 0,
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LINUX_SIGFPE, LINUX_SIGKILL, LINUX_SIGBUS, LINUX_SIGSEGV,
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0, LINUX_SIGPIPE, LINUX_SIGALRM, LINUX_SIGTERM,
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LINUX_SIGURG, LINUX_SIGSTOP, LINUX_SIGTSTP, LINUX_SIGCONT,
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LINUX_SIGCHLD, LINUX_SIGTTIN, LINUX_SIGTTOU, LINUX_SIGIO,
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LINUX_SIGXCPU, LINUX_SIGXFSZ, LINUX_SIGVTALRM, LINUX_SIGPROF,
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LINUX_SIGWINCH, 0, LINUX_SIGUSR1, LINUX_SIGUSR2
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};
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int linux_to_bsd_signal[LINUX_NSIG] = {
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0, SIGHUP, SIGINT, SIGQUIT, SIGILL, SIGTRAP, SIGABRT, SIGEMT,
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SIGFPE, SIGKILL, SIGUSR1, SIGSEGV, SIGUSR2, SIGPIPE, SIGALRM, SIGTERM,
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SIGBUS, SIGCHLD, SIGCONT, SIGSTOP, SIGTSTP, SIGTTIN, SIGTTOU, SIGIO,
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SIGXCPU, SIGXFSZ, SIGVTALRM, SIGPROF, SIGWINCH, SIGURG, SIGURG, 0
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};
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/*
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* If FreeBSD & Linux have a difference of opinion about what a trap
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* means, deal with it here.
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*/
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static int
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translate_traps(int signal, int trap_code)
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{
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if (signal != SIGBUS)
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return signal;
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switch (trap_code) {
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case T_PROTFLT:
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case T_TSSFLT:
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case T_DOUBLEFLT:
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case T_PAGEFLT:
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return SIGSEGV;
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default:
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return signal;
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}
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}
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static int
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linux_fixup(long **stack_base, struct image_params *imgp)
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{
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long *argv, *envp;
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argv = *stack_base;
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envp = *stack_base + (imgp->argc + 1);
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(*stack_base)--;
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**stack_base = (intptr_t)(void *)envp;
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(*stack_base)--;
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**stack_base = (intptr_t)(void *)argv;
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(*stack_base)--;
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**stack_base = imgp->argc;
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return 0;
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}
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static int
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elf_linux_fixup(long **stack_base, struct image_params *imgp)
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{
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Elf32_Auxargs *args = (Elf32_Auxargs *)imgp->auxargs;
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long *pos;
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pos = *stack_base + (imgp->argc + imgp->envc + 2);
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if (args->trace) {
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AUXARGS_ENTRY(pos, AT_DEBUG, 1);
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}
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if (args->execfd != -1) {
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AUXARGS_ENTRY(pos, AT_EXECFD, args->execfd);
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}
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AUXARGS_ENTRY(pos, AT_PHDR, args->phdr);
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AUXARGS_ENTRY(pos, AT_PHENT, args->phent);
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AUXARGS_ENTRY(pos, AT_PHNUM, args->phnum);
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AUXARGS_ENTRY(pos, AT_PAGESZ, args->pagesz);
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AUXARGS_ENTRY(pos, AT_FLAGS, args->flags);
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AUXARGS_ENTRY(pos, AT_ENTRY, args->entry);
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AUXARGS_ENTRY(pos, AT_BASE, args->base);
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AUXARGS_ENTRY(pos, AT_UID, imgp->proc->p_cred->p_ruid);
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AUXARGS_ENTRY(pos, AT_EUID, imgp->proc->p_cred->p_svuid);
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AUXARGS_ENTRY(pos, AT_GID, imgp->proc->p_cred->p_rgid);
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AUXARGS_ENTRY(pos, AT_EGID, imgp->proc->p_cred->p_svgid);
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AUXARGS_ENTRY(pos, AT_NULL, 0);
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free(imgp->auxargs, M_TEMP);
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imgp->auxargs = NULL;
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(*stack_base)--;
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**stack_base = (long)imgp->argc;
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return 0;
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}
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extern int _ucodesel, _udatasel;
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/*
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* Send an interrupt to process.
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*
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* Stack is set up to allow sigcode stored
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* in u. to call routine, followed by kcall
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* to sigreturn routine below. After sigreturn
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* resets the signal mask, the stack, and the
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* frame pointer, it returns to the user
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* specified pc, psl.
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*/
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static void
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linux_sendsig(sig_t catcher, int sig, int mask, u_long code)
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{
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register struct proc *p = curproc;
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register struct trapframe *regs;
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struct linux_sigframe *fp, frame;
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struct sigacts *psp = p->p_sigacts;
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int oonstack;
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regs = p->p_md.md_regs;
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oonstack = psp->ps_sigstk.ss_flags & SS_ONSTACK;
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#ifdef DEBUG
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printf("Linux-emul(%ld): linux_sendsig(%p, %d, %d, %lu)\n",
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(long)p->p_pid, catcher, sig, mask, code);
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#endif
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/*
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* Allocate space for the signal handler context.
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*/
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if ((psp->ps_flags & SAS_ALTSTACK) && !oonstack &&
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(psp->ps_sigonstack & sigmask(sig))) {
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fp = (struct linux_sigframe *)(psp->ps_sigstk.ss_sp +
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psp->ps_sigstk.ss_size - sizeof(struct linux_sigframe));
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psp->ps_sigstk.ss_flags |= SS_ONSTACK;
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} else {
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fp = (struct linux_sigframe *)regs->tf_esp - 1;
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}
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/*
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* grow() will return FALSE if the fp will not fit inside the stack
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* and the stack can not be grown. useracc will return FALSE
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* if access is denied.
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*/
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if ((grow(p, (int)fp) == FALSE) ||
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(useracc((caddr_t)fp, sizeof (struct linux_sigframe), B_WRITE) == FALSE)) {
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/*
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* Process has trashed its stack; give it an illegal
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* instruction to halt it in its tracks.
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*/
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SIGACTION(p, SIGILL) = SIG_DFL;
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sig = sigmask(SIGILL);
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p->p_sigignore &= ~sig;
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p->p_sigcatch &= ~sig;
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p->p_sigmask &= ~sig;
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psignal(p, SIGILL);
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return;
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}
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/*
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* Build the argument list for the signal handler.
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*/
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if (p->p_sysent->sv_sigtbl) {
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if (sig < p->p_sysent->sv_sigsize)
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sig = p->p_sysent->sv_sigtbl[sig];
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else
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sig = p->p_sysent->sv_sigsize + 1;
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}
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frame.sf_handler = catcher;
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frame.sf_sig = sig;
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/*
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* Build the signal context to be used by sigreturn.
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*/
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frame.sf_sc.sc_mask = mask;
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__asm("movl %%gs,%w0" : "=r" (frame.sf_sc.sc_gs));
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__asm("movl %%fs,%w0" : "=r" (frame.sf_sc.sc_fs));
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frame.sf_sc.sc_es = regs->tf_es;
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frame.sf_sc.sc_ds = regs->tf_ds;
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frame.sf_sc.sc_edi = regs->tf_edi;
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frame.sf_sc.sc_esi = regs->tf_esi;
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frame.sf_sc.sc_ebp = regs->tf_ebp;
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frame.sf_sc.sc_ebx = regs->tf_ebx;
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frame.sf_sc.sc_edx = regs->tf_edx;
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frame.sf_sc.sc_ecx = regs->tf_ecx;
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frame.sf_sc.sc_eax = regs->tf_eax;
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frame.sf_sc.sc_eip = regs->tf_eip;
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frame.sf_sc.sc_cs = regs->tf_cs;
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frame.sf_sc.sc_eflags = regs->tf_eflags;
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frame.sf_sc.sc_esp_at_signal = regs->tf_esp;
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frame.sf_sc.sc_ss = regs->tf_ss;
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frame.sf_sc.sc_err = regs->tf_err;
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frame.sf_sc.sc_trapno = code; /* XXX ???? */
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if (copyout(&frame, fp, sizeof(frame)) != 0) {
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/*
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* Process has trashed its stack; give it an illegal
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* instruction to halt it in its tracks.
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*/
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sigexit(p, SIGILL);
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/* NOTREACHED */
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}
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/*
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* Build context to run handler in.
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*/
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regs->tf_esp = (int)fp;
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regs->tf_eip = (int)(((char *)PS_STRINGS) - *(p->p_sysent->sv_szsigcode));
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regs->tf_eflags &= ~PSL_VM;
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regs->tf_cs = _ucodesel;
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regs->tf_ds = _udatasel;
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regs->tf_es = _udatasel;
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regs->tf_ss = _udatasel;
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}
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/*
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* System call to cleanup state after a signal
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* has been taken. Reset signal mask and
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* stack state from context left by sendsig (above).
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* Return to previous pc and psl as specified by
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* context left by sendsig. Check carefully to
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* make sure that the user has not modified the
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* psl to gain improper privileges or to cause
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* a machine fault.
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*/
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int
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linux_sigreturn(p, args)
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struct proc *p;
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struct linux_sigreturn_args *args;
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{
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struct linux_sigcontext *scp, context;
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register struct trapframe *regs;
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int eflags;
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regs = p->p_md.md_regs;
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#ifdef DEBUG
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printf("Linux-emul(%ld): linux_sigreturn(%p)\n",
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(long)p->p_pid, (void *)args->scp);
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#endif
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/*
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* The trampoline code hands us the context.
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* It is unsafe to keep track of it ourselves, in the event that a
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* program jumps out of a signal handler.
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*/
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scp = SCARG(args,scp);
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if (copyin((caddr_t)scp, &context, sizeof(*scp)) != 0)
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return (EFAULT);
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/*
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* Check for security violations.
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*/
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#define EFLAGS_SECURE(ef, oef) ((((ef) ^ (oef)) & ~PSL_USERCHANGE) == 0)
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eflags = context.sc_eflags;
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/*
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* XXX do allow users to change the privileged flag PSL_RF. The
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* cpu sets PSL_RF in tf_eflags for faults. Debuggers should
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* sometimes set it there too. tf_eflags is kept in the signal
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* context during signal handling and there is no other place
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* to remember it, so the PSL_RF bit may be corrupted by the
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* signal handler without us knowing. Corruption of the PSL_RF
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* bit at worst causes one more or one less debugger trap, so
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* allowing it is fairly harmless.
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*/
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if (!EFLAGS_SECURE(eflags & ~PSL_RF, regs->tf_eflags & ~PSL_RF)) {
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return(EINVAL);
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}
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/*
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* Don't allow users to load a valid privileged %cs. Let the
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* hardware check for invalid selectors, excess privilege in
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* other selectors, invalid %eip's and invalid %esp's.
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*/
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#define CS_SECURE(cs) (ISPL(cs) == SEL_UPL)
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if (!CS_SECURE(context.sc_cs)) {
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trapsignal(p, SIGBUS, T_PROTFLT);
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return(EINVAL);
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}
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p->p_sigacts->ps_sigstk.ss_flags &= ~SS_ONSTACK;
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p->p_sigmask = context.sc_mask &~
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(sigmask(SIGKILL)|sigmask(SIGCONT)|sigmask(SIGSTOP));
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/*
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* Restore signal context.
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*/
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/* %fs and %gs were restored by the trampoline. */
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regs->tf_es = context.sc_es;
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regs->tf_ds = context.sc_ds;
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regs->tf_edi = context.sc_edi;
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regs->tf_esi = context.sc_esi;
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regs->tf_ebp = context.sc_ebp;
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regs->tf_ebx = context.sc_ebx;
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regs->tf_edx = context.sc_edx;
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regs->tf_ecx = context.sc_ecx;
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regs->tf_eax = context.sc_eax;
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regs->tf_eip = context.sc_eip;
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regs->tf_cs = context.sc_cs;
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regs->tf_eflags = eflags;
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regs->tf_esp = context.sc_esp_at_signal;
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regs->tf_ss = context.sc_ss;
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return (EJUSTRETURN);
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}
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static void
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linux_prepsyscall(struct trapframe *tf, int *args, u_int *code, caddr_t *params)
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{
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args[0] = tf->tf_ebx;
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args[1] = tf->tf_ecx;
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args[2] = tf->tf_edx;
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args[3] = tf->tf_esi;
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args[4] = tf->tf_edi;
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*params = NULL; /* no copyin */
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}
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struct sysentvec linux_sysvec = {
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LINUX_SYS_MAXSYSCALL,
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linux_sysent,
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0xff,
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NSIG,
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bsd_to_linux_signal,
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ELAST,
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bsd_to_linux_errno,
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translate_traps,
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linux_fixup,
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linux_sendsig,
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linux_sigcode,
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&linux_szsigcode,
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linux_prepsyscall,
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"Linux a.out"
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};
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struct sysentvec elf_linux_sysvec = {
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LINUX_SYS_MAXSYSCALL,
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linux_sysent,
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0xff,
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NSIG,
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bsd_to_linux_signal,
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ELAST,
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bsd_to_linux_errno,
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translate_traps,
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elf_linux_fixup,
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linux_sendsig,
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linux_sigcode,
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&linux_szsigcode,
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linux_prepsyscall,
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"Linux ELF"
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};
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/*
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* Installed either via SYSINIT() or via LKM stubs.
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*/
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Elf32_Brandinfo linux_brand = {
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"Linux",
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"/compat/linux",
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"/lib/ld-linux.so.1",
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&elf_linux_sysvec
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};
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#ifndef LKM
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/*
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* XXX: this is WRONG, it needs to be SI_SUB_EXEC, but this is just at the
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* "proof of concept" stage and will be fixed shortly
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*/
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static void linux_elf_init __P((void *dummy));
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static void
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linux_elf_init(dummy)
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void *dummy;
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{
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if (elf_insert_brand_entry(&linux_brand) < 0)
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printf("cannot insert Linux elf brand handler\n");
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else if (bootverbose)
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printf("Linux-ELF exec handler installed\n");
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}
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SYSINIT(linuxelf, SI_SUB_VFS, SI_ORDER_ANY, linux_elf_init, NULL);
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#endif
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