Index: head/sys/amd64/linux32/linux32_sysvec.c
===================================================================
--- head/sys/amd64/linux32/linux32_sysvec.c	(revision 340184)
+++ head/sys/amd64/linux32/linux32_sysvec.c	(revision 340185)
@@ -1,1117 +1,1119 @@
 /*-
  * SPDX-License-Identifier: BSD-3-Clause
  *
  * Copyright (c) 2004 Tim J. Robbins
  * Copyright (c) 2003 Peter Wemm
  * Copyright (c) 2002 Doug Rabson
  * Copyright (c) 1998-1999 Andrew Gallatin
  * Copyright (c) 1994-1996 Søren Schmidt
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer
  *    in this position and unchanged.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
  *    documentation and/or other materials provided with the distribution.
  * 3. The name of the author may not be used to endorse or promote products
  *    derived from this software without specific prior written permission
  *
  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
+#include "opt_compat.h"
+
 #include <sys/cdefs.h>
 __FBSDID("$FreeBSD$");
 
 #ifndef COMPAT_FREEBSD32
 #error "Unable to compile Linux-emulator due to missing COMPAT_FREEBSD32 option!"
 #endif
 
 #define	__ELF_WORD_SIZE	32
 
 #include <sys/param.h>
 #include <sys/systm.h>
 #include <sys/exec.h>
 #include <sys/fcntl.h>
 #include <sys/imgact.h>
 #include <sys/imgact_elf.h>
 #include <sys/kernel.h>
 #include <sys/lock.h>
 #include <sys/malloc.h>
 #include <sys/module.h>
 #include <sys/mutex.h>
 #include <sys/proc.h>
 #include <sys/resourcevar.h>
 #include <sys/signalvar.h>
 #include <sys/syscallsubr.h>
 #include <sys/sysctl.h>
 #include <sys/sysent.h>
 #include <sys/sysproto.h>
 #include <sys/vnode.h>
 #include <sys/eventhandler.h>
 
 #include <vm/vm.h>
 #include <vm/pmap.h>
 #include <vm/vm_extern.h>
 #include <vm/vm_map.h>
 #include <vm/vm_object.h>
 #include <vm/vm_page.h>
 #include <vm/vm_param.h>
 
 #include <machine/cpu.h>
 #include <machine/md_var.h>
 #include <machine/pcb.h>
 #include <machine/specialreg.h>
 #include <machine/trap.h>
 
 #include <amd64/linux32/linux.h>
 #include <amd64/linux32/linux32_proto.h>
 #include <compat/linux/linux_emul.h>
 #include <compat/linux/linux_futex.h>
 #include <compat/linux/linux_ioctl.h>
 #include <compat/linux/linux_mib.h>
 #include <compat/linux/linux_misc.h>
 #include <compat/linux/linux_signal.h>
 #include <compat/linux/linux_util.h>
 #include <compat/linux/linux_vdso.h>
 
 MODULE_VERSION(linux, 1);
 
 /*
  * Allow the sendsig functions to use the ldebug() facility even though they
  * are not syscalls themselves.  Map them to syscall 0.  This is slightly less
  * bogus than using ldebug(sigreturn).
  */
 #define	LINUX32_SYS_linux_rt_sendsig	0
 #define	LINUX32_SYS_linux_sendsig	0
 
 const char *linux_kplatform;
 static int linux_szsigcode;
 static vm_object_t linux_shared_page_obj;
 static char *linux_shared_page_mapping;
 extern char _binary_linux32_locore_o_start;
 extern char _binary_linux32_locore_o_end;
 
 extern struct sysent linux32_sysent[LINUX32_SYS_MAXSYSCALL];
 
 SET_DECLARE(linux_ioctl_handler_set, struct linux_ioctl_handler);
 
 static int	linux_fixup_elf(register_t **stack_base,
 		    struct image_params *iparams);
 static register_t *linux_copyout_strings(struct image_params *imgp);
 static void     linux_sendsig(sig_t catcher, ksiginfo_t *ksi, sigset_t *mask);
 static void	linux_exec_setregs(struct thread *td,
 				   struct image_params *imgp, u_long stack);
 static void	linux32_fixlimit(struct rlimit *rl, int which);
 static bool	linux32_trans_osrel(const Elf_Note *note, int32_t *osrel);
 static void	linux_vdso_install(void *param);
 static void	linux_vdso_deinstall(void *param);
 
 #define LINUX_T_UNKNOWN  255
 static int _bsd_to_linux_trapcode[] = {
 	LINUX_T_UNKNOWN,	/* 0 */
 	6,			/* 1  T_PRIVINFLT */
 	LINUX_T_UNKNOWN,	/* 2 */
 	3,			/* 3  T_BPTFLT */
 	LINUX_T_UNKNOWN,	/* 4 */
 	LINUX_T_UNKNOWN,	/* 5 */
 	16,			/* 6  T_ARITHTRAP */
 	254,			/* 7  T_ASTFLT */
 	LINUX_T_UNKNOWN,	/* 8 */
 	13,			/* 9  T_PROTFLT */
 	1,			/* 10 T_TRCTRAP */
 	LINUX_T_UNKNOWN,	/* 11 */
 	14,			/* 12 T_PAGEFLT */
 	LINUX_T_UNKNOWN,	/* 13 */
 	17,			/* 14 T_ALIGNFLT */
 	LINUX_T_UNKNOWN,	/* 15 */
 	LINUX_T_UNKNOWN,	/* 16 */
 	LINUX_T_UNKNOWN,	/* 17 */
 	0,			/* 18 T_DIVIDE */
 	2,			/* 19 T_NMI */
 	4,			/* 20 T_OFLOW */
 	5,			/* 21 T_BOUND */
 	7,			/* 22 T_DNA */
 	8,			/* 23 T_DOUBLEFLT */
 	9,			/* 24 T_FPOPFLT */
 	10,			/* 25 T_TSSFLT */
 	11,			/* 26 T_SEGNPFLT */
 	12,			/* 27 T_STKFLT */
 	18,			/* 28 T_MCHK */
 	19,			/* 29 T_XMMFLT */
 	15			/* 30 T_RESERVED */
 };
 #define bsd_to_linux_trapcode(code) \
     ((code)<nitems(_bsd_to_linux_trapcode)? \
      _bsd_to_linux_trapcode[(code)]: \
      LINUX_T_UNKNOWN)
 
 struct linux32_ps_strings {
 	u_int32_t ps_argvstr;	/* first of 0 or more argument strings */
 	u_int ps_nargvstr;	/* the number of argument strings */
 	u_int32_t ps_envstr;	/* first of 0 or more environment strings */
 	u_int ps_nenvstr;	/* the number of environment strings */
 };
 
 LINUX_VDSO_SYM_INTPTR(linux32_sigcode);
 LINUX_VDSO_SYM_INTPTR(linux32_rt_sigcode);
 LINUX_VDSO_SYM_INTPTR(linux32_vsyscall);
 LINUX_VDSO_SYM_CHAR(linux_platform);
 
 /*
  * If FreeBSD & Linux have a difference of opinion about what a trap
  * means, deal with it here.
  *
  * MPSAFE
  */
 static int
 linux_translate_traps(int signal, int trap_code)
 {
 	if (signal != SIGBUS)
 		return (signal);
 	switch (trap_code) {
 	case T_PROTFLT:
 	case T_TSSFLT:
 	case T_DOUBLEFLT:
 	case T_PAGEFLT:
 		return (SIGSEGV);
 	default:
 		return (signal);
 	}
 }
 
 static int
 linux_fixup_elf(register_t **stack_base, struct image_params *imgp)
 {
 	Elf32_Auxargs *args;
 	Elf32_Auxinfo *argarray, *pos;
 	Elf32_Addr *auxbase, *base;
 	struct linux32_ps_strings *arginfo;
 	int error, issetugid;
 
 	arginfo = (struct linux32_ps_strings *)LINUX32_PS_STRINGS;
 
 	KASSERT(curthread->td_proc == imgp->proc,
 	    ("unsafe linux_fixup_elf(), should be curproc"));
 	base = (Elf32_Addr *)*stack_base;
 	args = (Elf32_Auxargs *)imgp->auxargs;
 	auxbase = base + (imgp->args->argc + 1 + imgp->args->envc + 1);
 	argarray = pos = malloc(LINUX_AT_COUNT * sizeof(*pos), M_TEMP,
 	    M_WAITOK | M_ZERO);
 
 	issetugid = imgp->proc->p_flag & P_SUGID ? 1 : 0;
 	AUXARGS_ENTRY(pos, LINUX_AT_SYSINFO_EHDR,
 	    imgp->proc->p_sysent->sv_shared_page_base);
 	AUXARGS_ENTRY(pos, LINUX_AT_SYSINFO, linux32_vsyscall);
 	AUXARGS_ENTRY(pos, LINUX_AT_HWCAP, cpu_feature);
 
 	/*
 	 * Do not export AT_CLKTCK when emulating Linux kernel prior to 2.4.0,
 	 * as it has appeared in the 2.4.0-rc7 first time.
 	 * Being exported, AT_CLKTCK is returned by sysconf(_SC_CLK_TCK),
 	 * glibc falls back to the hard-coded CLK_TCK value when aux entry
 	 * is not present.
 	 * Also see linux_times() implementation.
 	 */
 	if (linux_kernver(curthread) >= LINUX_KERNVER_2004000)
 		AUXARGS_ENTRY(pos, LINUX_AT_CLKTCK, stclohz);
 	AUXARGS_ENTRY(pos, AT_PHDR, args->phdr);
 	AUXARGS_ENTRY(pos, AT_PHENT, args->phent);
 	AUXARGS_ENTRY(pos, AT_PHNUM, args->phnum);
 	AUXARGS_ENTRY(pos, AT_PAGESZ, args->pagesz);
 	AUXARGS_ENTRY(pos, AT_FLAGS, args->flags);
 	AUXARGS_ENTRY(pos, AT_ENTRY, args->entry);
 	AUXARGS_ENTRY(pos, AT_BASE, args->base);
 	AUXARGS_ENTRY(pos, LINUX_AT_SECURE, issetugid);
 	AUXARGS_ENTRY(pos, AT_UID, imgp->proc->p_ucred->cr_ruid);
 	AUXARGS_ENTRY(pos, AT_EUID, imgp->proc->p_ucred->cr_svuid);
 	AUXARGS_ENTRY(pos, AT_GID, imgp->proc->p_ucred->cr_rgid);
 	AUXARGS_ENTRY(pos, AT_EGID, imgp->proc->p_ucred->cr_svgid);
 	AUXARGS_ENTRY(pos, LINUX_AT_PLATFORM, PTROUT(linux_platform));
 	AUXARGS_ENTRY(pos, LINUX_AT_RANDOM, PTROUT(imgp->canary));
 	if (imgp->execpathp != 0)
 		AUXARGS_ENTRY(pos, LINUX_AT_EXECFN, PTROUT(imgp->execpathp));
 	if (args->execfd != -1)
 		AUXARGS_ENTRY(pos, AT_EXECFD, args->execfd);
 	AUXARGS_ENTRY(pos, AT_NULL, 0);
 
 	free(imgp->auxargs, M_TEMP);
 	imgp->auxargs = NULL;
 	KASSERT(pos - argarray <= LINUX_AT_COUNT, ("Too many auxargs"));
 
 	error = copyout(&argarray[0], auxbase,
 	    sizeof(*argarray) * LINUX_AT_COUNT);
 	free(argarray, M_TEMP);
 	if (error != 0)
 		return (error);
 
 	base--;
 	if (suword32(base, (uint32_t)imgp->args->argc) == -1)
 		return (EFAULT);
 	*stack_base = (register_t *)base;
 	return (0);
 }
 
 static void
 linux_rt_sendsig(sig_t catcher, ksiginfo_t *ksi, sigset_t *mask)
 {
 	struct thread *td = curthread;
 	struct proc *p = td->td_proc;
 	struct sigacts *psp;
 	struct trapframe *regs;
 	struct l_rt_sigframe *fp, frame;
 	int oonstack;
 	int sig;
 	int code;
 
 	sig = ksi->ksi_signo;
 	code = ksi->ksi_code;
 	PROC_LOCK_ASSERT(p, MA_OWNED);
 	psp = p->p_sigacts;
 	mtx_assert(&psp->ps_mtx, MA_OWNED);
 	regs = td->td_frame;
 	oonstack = sigonstack(regs->tf_rsp);
 
 #ifdef DEBUG
 	if (ldebug(rt_sendsig))
 		printf(ARGS(rt_sendsig, "%p, %d, %p, %u"),
 		    catcher, sig, (void*)mask, code);
 #endif
 	/* Allocate space for the signal handler context. */
 	if ((td->td_pflags & TDP_ALTSTACK) && !oonstack &&
 	    SIGISMEMBER(psp->ps_sigonstack, sig)) {
 		fp = (struct l_rt_sigframe *)((uintptr_t)td->td_sigstk.ss_sp +
 		    td->td_sigstk.ss_size - sizeof(struct l_rt_sigframe));
 	} else
 		fp = (struct l_rt_sigframe *)regs->tf_rsp - 1;
 	mtx_unlock(&psp->ps_mtx);
 
 	/* Build the argument list for the signal handler. */
 	sig = bsd_to_linux_signal(sig);
 
 	bzero(&frame, sizeof(frame));
 
 	frame.sf_handler = PTROUT(catcher);
 	frame.sf_sig = sig;
 	frame.sf_siginfo = PTROUT(&fp->sf_si);
 	frame.sf_ucontext = PTROUT(&fp->sf_sc);
 
 	/* Fill in POSIX parts. */
 	ksiginfo_to_lsiginfo(ksi, &frame.sf_si, sig);
 
 	/*
 	 * Build the signal context to be used by sigreturn and libgcc unwind.
 	 */
 	frame.sf_sc.uc_flags = 0;		/* XXX ??? */
 	frame.sf_sc.uc_link = 0;		/* XXX ??? */
 
 	frame.sf_sc.uc_stack.ss_sp = PTROUT(td->td_sigstk.ss_sp);
 	frame.sf_sc.uc_stack.ss_size = td->td_sigstk.ss_size;
 	frame.sf_sc.uc_stack.ss_flags = (td->td_pflags & TDP_ALTSTACK)
 	    ? ((oonstack) ? LINUX_SS_ONSTACK : 0) : LINUX_SS_DISABLE;
 	PROC_UNLOCK(p);
 
 	bsd_to_linux_sigset(mask, &frame.sf_sc.uc_sigmask);
 
 	frame.sf_sc.uc_mcontext.sc_mask   = frame.sf_sc.uc_sigmask.__mask;
 	frame.sf_sc.uc_mcontext.sc_edi    = regs->tf_rdi;
 	frame.sf_sc.uc_mcontext.sc_esi    = regs->tf_rsi;
 	frame.sf_sc.uc_mcontext.sc_ebp    = regs->tf_rbp;
 	frame.sf_sc.uc_mcontext.sc_ebx    = regs->tf_rbx;
 	frame.sf_sc.uc_mcontext.sc_esp    = regs->tf_rsp;
 	frame.sf_sc.uc_mcontext.sc_edx    = regs->tf_rdx;
 	frame.sf_sc.uc_mcontext.sc_ecx    = regs->tf_rcx;
 	frame.sf_sc.uc_mcontext.sc_eax    = regs->tf_rax;
 	frame.sf_sc.uc_mcontext.sc_eip    = regs->tf_rip;
 	frame.sf_sc.uc_mcontext.sc_cs     = regs->tf_cs;
 	frame.sf_sc.uc_mcontext.sc_gs     = regs->tf_gs;
 	frame.sf_sc.uc_mcontext.sc_fs     = regs->tf_fs;
 	frame.sf_sc.uc_mcontext.sc_es     = regs->tf_es;
 	frame.sf_sc.uc_mcontext.sc_ds     = regs->tf_ds;
 	frame.sf_sc.uc_mcontext.sc_eflags = regs->tf_rflags;
 	frame.sf_sc.uc_mcontext.sc_esp_at_signal = regs->tf_rsp;
 	frame.sf_sc.uc_mcontext.sc_ss     = regs->tf_ss;
 	frame.sf_sc.uc_mcontext.sc_err    = regs->tf_err;
 	frame.sf_sc.uc_mcontext.sc_cr2    = (u_int32_t)(uintptr_t)ksi->ksi_addr;
 	frame.sf_sc.uc_mcontext.sc_trapno = bsd_to_linux_trapcode(code);
 
 #ifdef DEBUG
 	if (ldebug(rt_sendsig))
 		printf(LMSG("rt_sendsig flags: 0x%x, sp: %p, ss: 0x%lx, mask: 0x%x"),
 		    frame.sf_sc.uc_stack.ss_flags, td->td_sigstk.ss_sp,
 		    td->td_sigstk.ss_size, frame.sf_sc.uc_mcontext.sc_mask);
 #endif
 
 	if (copyout(&frame, fp, sizeof(frame)) != 0) {
 		/*
 		 * Process has trashed its stack; give it an illegal
 		 * instruction to halt it in its tracks.
 		 */
 #ifdef DEBUG
 		if (ldebug(rt_sendsig))
 			printf(LMSG("rt_sendsig: bad stack %p, oonstack=%x"),
 			    fp, oonstack);
 #endif
 		PROC_LOCK(p);
 		sigexit(td, SIGILL);
 	}
 
 	/* Build context to run handler in. */
 	regs->tf_rsp = PTROUT(fp);
 	regs->tf_rip = linux32_rt_sigcode;
 	regs->tf_rflags &= ~(PSL_T | PSL_D);
 	regs->tf_cs = _ucode32sel;
 	regs->tf_ss = _udatasel;
 	regs->tf_ds = _udatasel;
 	regs->tf_es = _udatasel;
 	regs->tf_fs = _ufssel;
 	regs->tf_gs = _ugssel;
 	regs->tf_flags = TF_HASSEGS;
 	set_pcb_flags(td->td_pcb, PCB_FULL_IRET);
 	PROC_LOCK(p);
 	mtx_lock(&psp->ps_mtx);
 }
 
 
 /*
  * Send an interrupt to process.
  *
  * Stack is set up to allow sigcode stored
  * in u. to call routine, followed by kcall
  * to sigreturn routine below.  After sigreturn
  * resets the signal mask, the stack, and the
  * frame pointer, it returns to the user
  * specified pc, psl.
  */
 static void
 linux_sendsig(sig_t catcher, ksiginfo_t *ksi, sigset_t *mask)
 {
 	struct thread *td = curthread;
 	struct proc *p = td->td_proc;
 	struct sigacts *psp;
 	struct trapframe *regs;
 	struct l_sigframe *fp, frame;
 	l_sigset_t lmask;
 	int oonstack;
 	int sig, code;
 
 	sig = ksi->ksi_signo;
 	code = ksi->ksi_code;
 	PROC_LOCK_ASSERT(p, MA_OWNED);
 	psp = p->p_sigacts;
 	mtx_assert(&psp->ps_mtx, MA_OWNED);
 	if (SIGISMEMBER(psp->ps_siginfo, sig)) {
 		/* Signal handler installed with SA_SIGINFO. */
 		linux_rt_sendsig(catcher, ksi, mask);
 		return;
 	}
 
 	regs = td->td_frame;
 	oonstack = sigonstack(regs->tf_rsp);
 
 #ifdef DEBUG
 	if (ldebug(sendsig))
 		printf(ARGS(sendsig, "%p, %d, %p, %u"),
 		    catcher, sig, (void*)mask, code);
 #endif
 
 	/* Allocate space for the signal handler context. */
 	if ((td->td_pflags & TDP_ALTSTACK) && !oonstack &&
 	    SIGISMEMBER(psp->ps_sigonstack, sig)) {
 		fp = (struct l_sigframe *)((uintptr_t)td->td_sigstk.ss_sp +
 		    td->td_sigstk.ss_size - sizeof(struct l_sigframe));
 	} else
 		fp = (struct l_sigframe *)regs->tf_rsp - 1;
 	mtx_unlock(&psp->ps_mtx);
 	PROC_UNLOCK(p);
 
 	/* Build the argument list for the signal handler. */
 	sig = bsd_to_linux_signal(sig);
 
 	bzero(&frame, sizeof(frame));
 
 	frame.sf_handler = PTROUT(catcher);
 	frame.sf_sig = sig;
 
 	bsd_to_linux_sigset(mask, &lmask);
 
 	/* Build the signal context to be used by sigreturn. */
 	frame.sf_sc.sc_mask   = lmask.__mask;
 	frame.sf_sc.sc_gs     = regs->tf_gs;
 	frame.sf_sc.sc_fs     = regs->tf_fs;
 	frame.sf_sc.sc_es     = regs->tf_es;
 	frame.sf_sc.sc_ds     = regs->tf_ds;
 	frame.sf_sc.sc_edi    = regs->tf_rdi;
 	frame.sf_sc.sc_esi    = regs->tf_rsi;
 	frame.sf_sc.sc_ebp    = regs->tf_rbp;
 	frame.sf_sc.sc_ebx    = regs->tf_rbx;
 	frame.sf_sc.sc_esp    = regs->tf_rsp;
 	frame.sf_sc.sc_edx    = regs->tf_rdx;
 	frame.sf_sc.sc_ecx    = regs->tf_rcx;
 	frame.sf_sc.sc_eax    = regs->tf_rax;
 	frame.sf_sc.sc_eip    = regs->tf_rip;
 	frame.sf_sc.sc_cs     = regs->tf_cs;
 	frame.sf_sc.sc_eflags = regs->tf_rflags;
 	frame.sf_sc.sc_esp_at_signal = regs->tf_rsp;
 	frame.sf_sc.sc_ss     = regs->tf_ss;
 	frame.sf_sc.sc_err    = regs->tf_err;
 	frame.sf_sc.sc_cr2    = (u_int32_t)(uintptr_t)ksi->ksi_addr;
 	frame.sf_sc.sc_trapno = bsd_to_linux_trapcode(code);
 
 	frame.sf_extramask[0] = lmask.__mask;
 
 	if (copyout(&frame, fp, sizeof(frame)) != 0) {
 		/*
 		 * Process has trashed its stack; give it an illegal
 		 * instruction to halt it in its tracks.
 		 */
 		PROC_LOCK(p);
 		sigexit(td, SIGILL);
 	}
 
 	/* Build context to run handler in. */
 	regs->tf_rsp = PTROUT(fp);
 	regs->tf_rip = linux32_sigcode;
 	regs->tf_rflags &= ~(PSL_T | PSL_D);
 	regs->tf_cs = _ucode32sel;
 	regs->tf_ss = _udatasel;
 	regs->tf_ds = _udatasel;
 	regs->tf_es = _udatasel;
 	regs->tf_fs = _ufssel;
 	regs->tf_gs = _ugssel;
 	regs->tf_flags = TF_HASSEGS;
 	set_pcb_flags(td->td_pcb, PCB_FULL_IRET);
 	PROC_LOCK(p);
 	mtx_lock(&psp->ps_mtx);
 }
 
 /*
  * System call to cleanup state after a signal
  * has been taken.  Reset signal mask and
  * stack state from context left by sendsig (above).
  * Return to previous pc and psl as specified by
  * context left by sendsig. Check carefully to
  * make sure that the user has not modified the
  * psl to gain improper privileges or to cause
  * a machine fault.
  */
 int
 linux_sigreturn(struct thread *td, struct linux_sigreturn_args *args)
 {
 	struct l_sigframe frame;
 	struct trapframe *regs;
 	sigset_t bmask;
 	l_sigset_t lmask;
 	int eflags;
 	ksiginfo_t ksi;
 
 	regs = td->td_frame;
 
 #ifdef DEBUG
 	if (ldebug(sigreturn))
 		printf(ARGS(sigreturn, "%p"), (void *)args->sfp);
 #endif
 	/*
 	 * The trampoline code hands us the sigframe.
 	 * It is unsafe to keep track of it ourselves, in the event that a
 	 * program jumps out of a signal handler.
 	 */
 	if (copyin(args->sfp, &frame, sizeof(frame)) != 0)
 		return (EFAULT);
 
 	/* Check for security violations. */
 #define	EFLAGS_SECURE(ef, oef)	((((ef) ^ (oef)) & ~PSL_USERCHANGE) == 0)
 	eflags = frame.sf_sc.sc_eflags;
 	if (!EFLAGS_SECURE(eflags, regs->tf_rflags))
 		return(EINVAL);
 
 	/*
 	 * Don't allow users to load a valid privileged %cs.  Let the
 	 * hardware check for invalid selectors, excess privilege in
 	 * other selectors, invalid %eip's and invalid %esp's.
 	 */
 #define	CS_SECURE(cs)	(ISPL(cs) == SEL_UPL)
 	if (!CS_SECURE(frame.sf_sc.sc_cs)) {
 		ksiginfo_init_trap(&ksi);
 		ksi.ksi_signo = SIGBUS;
 		ksi.ksi_code = BUS_OBJERR;
 		ksi.ksi_trapno = T_PROTFLT;
 		ksi.ksi_addr = (void *)regs->tf_rip;
 		trapsignal(td, &ksi);
 		return(EINVAL);
 	}
 
 	lmask.__mask = frame.sf_sc.sc_mask;
 	lmask.__mask = frame.sf_extramask[0];
 	linux_to_bsd_sigset(&lmask, &bmask);
 	kern_sigprocmask(td, SIG_SETMASK, &bmask, NULL, 0);
 
 	/* Restore signal context. */
 	regs->tf_rdi    = frame.sf_sc.sc_edi;
 	regs->tf_rsi    = frame.sf_sc.sc_esi;
 	regs->tf_rbp    = frame.sf_sc.sc_ebp;
 	regs->tf_rbx    = frame.sf_sc.sc_ebx;
 	regs->tf_rdx    = frame.sf_sc.sc_edx;
 	regs->tf_rcx    = frame.sf_sc.sc_ecx;
 	regs->tf_rax    = frame.sf_sc.sc_eax;
 	regs->tf_rip    = frame.sf_sc.sc_eip;
 	regs->tf_cs     = frame.sf_sc.sc_cs;
 	regs->tf_ds     = frame.sf_sc.sc_ds;
 	regs->tf_es     = frame.sf_sc.sc_es;
 	regs->tf_fs     = frame.sf_sc.sc_fs;
 	regs->tf_gs     = frame.sf_sc.sc_gs;
 	regs->tf_rflags = eflags;
 	regs->tf_rsp    = frame.sf_sc.sc_esp_at_signal;
 	regs->tf_ss     = frame.sf_sc.sc_ss;
 	set_pcb_flags(td->td_pcb, PCB_FULL_IRET);
 
 	return (EJUSTRETURN);
 }
 
 /*
  * System call to cleanup state after a signal
  * has been taken.  Reset signal mask and
  * stack state from context left by rt_sendsig (above).
  * Return to previous pc and psl as specified by
  * context left by sendsig. Check carefully to
  * make sure that the user has not modified the
  * psl to gain improper privileges or to cause
  * a machine fault.
  */
 int
 linux_rt_sigreturn(struct thread *td, struct linux_rt_sigreturn_args *args)
 {
 	struct l_ucontext uc;
 	struct l_sigcontext *context;
 	sigset_t bmask;
 	l_stack_t *lss;
 	stack_t ss;
 	struct trapframe *regs;
 	int eflags;
 	ksiginfo_t ksi;
 
 	regs = td->td_frame;
 
 #ifdef DEBUG
 	if (ldebug(rt_sigreturn))
 		printf(ARGS(rt_sigreturn, "%p"), (void *)args->ucp);
 #endif
 	/*
 	 * The trampoline code hands us the ucontext.
 	 * It is unsafe to keep track of it ourselves, in the event that a
 	 * program jumps out of a signal handler.
 	 */
 	if (copyin(args->ucp, &uc, sizeof(uc)) != 0)
 		return (EFAULT);
 
 	context = &uc.uc_mcontext;
 
 	/* Check for security violations. */
 #define	EFLAGS_SECURE(ef, oef)	((((ef) ^ (oef)) & ~PSL_USERCHANGE) == 0)
 	eflags = context->sc_eflags;
 	if (!EFLAGS_SECURE(eflags, regs->tf_rflags))
 		return(EINVAL);
 
 	/*
 	 * Don't allow users to load a valid privileged %cs.  Let the
 	 * hardware check for invalid selectors, excess privilege in
 	 * other selectors, invalid %eip's and invalid %esp's.
 	 */
 #define	CS_SECURE(cs)	(ISPL(cs) == SEL_UPL)
 	if (!CS_SECURE(context->sc_cs)) {
 		ksiginfo_init_trap(&ksi);
 		ksi.ksi_signo = SIGBUS;
 		ksi.ksi_code = BUS_OBJERR;
 		ksi.ksi_trapno = T_PROTFLT;
 		ksi.ksi_addr = (void *)regs->tf_rip;
 		trapsignal(td, &ksi);
 		return(EINVAL);
 	}
 
 	linux_to_bsd_sigset(&uc.uc_sigmask, &bmask);
 	kern_sigprocmask(td, SIG_SETMASK, &bmask, NULL, 0);
 
 	/*
 	 * Restore signal context
 	 */
 	regs->tf_gs	= context->sc_gs;
 	regs->tf_fs	= context->sc_fs;
 	regs->tf_es	= context->sc_es;
 	regs->tf_ds	= context->sc_ds;
 	regs->tf_rdi    = context->sc_edi;
 	regs->tf_rsi    = context->sc_esi;
 	regs->tf_rbp    = context->sc_ebp;
 	regs->tf_rbx    = context->sc_ebx;
 	regs->tf_rdx    = context->sc_edx;
 	regs->tf_rcx    = context->sc_ecx;
 	regs->tf_rax    = context->sc_eax;
 	regs->tf_rip    = context->sc_eip;
 	regs->tf_cs     = context->sc_cs;
 	regs->tf_rflags = eflags;
 	regs->tf_rsp    = context->sc_esp_at_signal;
 	regs->tf_ss     = context->sc_ss;
 	set_pcb_flags(td->td_pcb, PCB_FULL_IRET);
 
 	/*
 	 * call sigaltstack & ignore results..
 	 */
 	lss = &uc.uc_stack;
 	ss.ss_sp = PTRIN(lss->ss_sp);
 	ss.ss_size = lss->ss_size;
 	ss.ss_flags = linux_to_bsd_sigaltstack(lss->ss_flags);
 
 #ifdef DEBUG
 	if (ldebug(rt_sigreturn))
 		printf(LMSG("rt_sigret flags: 0x%x, sp: %p, ss: 0x%lx, mask: 0x%x"),
 		    ss.ss_flags, ss.ss_sp, ss.ss_size, context->sc_mask);
 #endif
 	(void)kern_sigaltstack(td, &ss, NULL);
 
 	return (EJUSTRETURN);
 }
 
 static int
 linux32_fetch_syscall_args(struct thread *td)
 {
 	struct proc *p;
 	struct trapframe *frame;
 	struct syscall_args *sa;
 
 	p = td->td_proc;
 	frame = td->td_frame;
 	sa = &td->td_sa;
 
 	sa->args[0] = frame->tf_rbx;
 	sa->args[1] = frame->tf_rcx;
 	sa->args[2] = frame->tf_rdx;
 	sa->args[3] = frame->tf_rsi;
 	sa->args[4] = frame->tf_rdi;
 	sa->args[5] = frame->tf_rbp;	/* Unconfirmed */
 	sa->code = frame->tf_rax;
 
 	if (sa->code >= p->p_sysent->sv_size)
 		/* nosys */
 		sa->callp = &p->p_sysent->sv_table[p->p_sysent->sv_size - 1];
 	else
 		sa->callp = &p->p_sysent->sv_table[sa->code];
 	sa->narg = sa->callp->sy_narg;
 
 	td->td_retval[0] = 0;
 	td->td_retval[1] = frame->tf_rdx;
 
 	return (0);
 }
 
 /*
  * Clear registers on exec
  * XXX copied from ia32_signal.c.
  */
 static void
 linux_exec_setregs(struct thread *td, struct image_params *imgp, u_long stack)
 {
 	struct trapframe *regs = td->td_frame;
 	struct pcb *pcb = td->td_pcb;
 	register_t saved_rflags;
 
 	regs = td->td_frame;
 	pcb = td->td_pcb;
 
 	if (td->td_proc->p_md.md_ldt != NULL)
 		user_ldt_free(td);
 
 	critical_enter();
 	wrmsr(MSR_FSBASE, 0);
 	wrmsr(MSR_KGSBASE, 0);	/* User value while we're in the kernel */
 	pcb->pcb_fsbase = 0;
 	pcb->pcb_gsbase = 0;
 	critical_exit();
 	pcb->pcb_initial_fpucw = __LINUX_NPXCW__;
 
 	saved_rflags = regs->tf_rflags & PSL_T;
 	bzero((char *)regs, sizeof(struct trapframe));
 	regs->tf_rip = imgp->entry_addr;
 	regs->tf_rsp = stack;
 	regs->tf_rflags = PSL_USER | saved_rflags;
 	regs->tf_gs = _ugssel;
 	regs->tf_fs = _ufssel;
 	regs->tf_es = _udatasel;
 	regs->tf_ds = _udatasel;
 	regs->tf_ss = _udatasel;
 	regs->tf_flags = TF_HASSEGS;
 	regs->tf_cs = _ucode32sel;
 	regs->tf_rbx = imgp->ps_strings;
 
 	fpstate_drop(td);
 
 	/* Do full restore on return so that we can change to a different %cs */
 	set_pcb_flags(pcb, PCB_32BIT | PCB_FULL_IRET);
 }
 
 /*
  * XXX copied from ia32_sysvec.c.
  */
 static register_t *
 linux_copyout_strings(struct image_params *imgp)
 {
 	int argc, envc;
 	u_int32_t *vectp;
 	char *stringp, *destp;
 	u_int32_t *stack_base;
 	struct linux32_ps_strings *arginfo;
 	char canary[LINUX_AT_RANDOM_LEN];
 	size_t execpath_len;
 
 	/* Calculate string base and vector table pointers. */
 	if (imgp->execpath != NULL && imgp->auxargs != NULL)
 		execpath_len = strlen(imgp->execpath) + 1;
 	else
 		execpath_len = 0;
 
 	arginfo = (struct linux32_ps_strings *)LINUX32_PS_STRINGS;
 	destp =	(caddr_t)arginfo - SPARE_USRSPACE -
 	    roundup(sizeof(canary), sizeof(char *)) -
 	    roundup(execpath_len, sizeof(char *)) -
 	    roundup(ARG_MAX - imgp->args->stringspace, sizeof(char *));
 
 	if (execpath_len != 0) {
 		imgp->execpathp = (uintptr_t)arginfo - execpath_len;
 		copyout(imgp->execpath, (void *)imgp->execpathp, execpath_len);
 	}
 
 	/* Prepare the canary for SSP. */
 	arc4rand(canary, sizeof(canary), 0);
 	imgp->canary = (uintptr_t)arginfo -
 	    roundup(execpath_len, sizeof(char *)) -
 	    roundup(sizeof(canary), sizeof(char *));
 	copyout(canary, (void *)imgp->canary, sizeof(canary));
 
 	vectp = (uint32_t *)destp;
 	if (imgp->auxargs) {
 		/*
 		 * Allocate room on the stack for the ELF auxargs
 		 * array.  It has LINUX_AT_COUNT entries.
 		 */
 		vectp -= howmany(LINUX_AT_COUNT * sizeof(Elf32_Auxinfo),
 		    sizeof(*vectp));
 	}
 
 	/*
 	 * Allocate room for the argv[] and env vectors including the
 	 * terminating NULL pointers.
 	 */
 	vectp -= imgp->args->argc + 1 + imgp->args->envc + 1;
 
 	/* vectp also becomes our initial stack base. */
 	stack_base = vectp;
 
 	stringp = imgp->args->begin_argv;
 	argc = imgp->args->argc;
 	envc = imgp->args->envc;
 	/* Copy out strings - arguments and environment. */
 	copyout(stringp, destp, ARG_MAX - imgp->args->stringspace);
 
 	/* Fill in "ps_strings" struct for ps, w, etc. */
 	suword32(&arginfo->ps_argvstr, (uint32_t)(intptr_t)vectp);
 	suword32(&arginfo->ps_nargvstr, argc);
 
 	/* Fill in argument portion of vector table. */
 	for (; argc > 0; --argc) {
 		suword32(vectp++, (uint32_t)(intptr_t)destp);
 		while (*stringp++ != 0)
 			destp++;
 		destp++;
 	}
 
 	/* A null vector table pointer separates the argp's from the envp's. */
 	suword32(vectp++, 0);
 
 	suword32(&arginfo->ps_envstr, (uint32_t)(intptr_t)vectp);
 	suword32(&arginfo->ps_nenvstr, envc);
 
 	/* Fill in environment portion of vector table. */
 	for (; envc > 0; --envc) {
 		suword32(vectp++, (uint32_t)(intptr_t)destp);
 		while (*stringp++ != 0)
 			destp++;
 		destp++;
 	}
 
 	/* The end of the vector table is a null pointer. */
 	suword32(vectp, 0);
 
 	return ((register_t *)stack_base);
 }
 
 static SYSCTL_NODE(_compat, OID_AUTO, linux32, CTLFLAG_RW, 0,
     "32-bit Linux emulation");
 
 static u_long	linux32_maxdsiz = LINUX32_MAXDSIZ;
 SYSCTL_ULONG(_compat_linux32, OID_AUTO, maxdsiz, CTLFLAG_RW,
     &linux32_maxdsiz, 0, "");
 static u_long	linux32_maxssiz = LINUX32_MAXSSIZ;
 SYSCTL_ULONG(_compat_linux32, OID_AUTO, maxssiz, CTLFLAG_RW,
     &linux32_maxssiz, 0, "");
 static u_long	linux32_maxvmem = LINUX32_MAXVMEM;
 SYSCTL_ULONG(_compat_linux32, OID_AUTO, maxvmem, CTLFLAG_RW,
     &linux32_maxvmem, 0, "");
 
 #if defined(DEBUG)
 SYSCTL_PROC(_compat_linux32, OID_AUTO, debug, CTLTYPE_STRING | CTLFLAG_RW, 0, 0,
     linux_sysctl_debug, "A", "Linux debugging control");
 #endif
 
 static void
 linux32_fixlimit(struct rlimit *rl, int which)
 {
 
 	switch (which) {
 	case RLIMIT_DATA:
 		if (linux32_maxdsiz != 0) {
 			if (rl->rlim_cur > linux32_maxdsiz)
 				rl->rlim_cur = linux32_maxdsiz;
 			if (rl->rlim_max > linux32_maxdsiz)
 				rl->rlim_max = linux32_maxdsiz;
 		}
 		break;
 	case RLIMIT_STACK:
 		if (linux32_maxssiz != 0) {
 			if (rl->rlim_cur > linux32_maxssiz)
 				rl->rlim_cur = linux32_maxssiz;
 			if (rl->rlim_max > linux32_maxssiz)
 				rl->rlim_max = linux32_maxssiz;
 		}
 		break;
 	case RLIMIT_VMEM:
 		if (linux32_maxvmem != 0) {
 			if (rl->rlim_cur > linux32_maxvmem)
 				rl->rlim_cur = linux32_maxvmem;
 			if (rl->rlim_max > linux32_maxvmem)
 				rl->rlim_max = linux32_maxvmem;
 		}
 		break;
 	}
 }
 
 struct sysentvec elf_linux_sysvec = {
 	.sv_size	= LINUX32_SYS_MAXSYSCALL,
 	.sv_table	= linux32_sysent,
 	.sv_mask	= 0,
 	.sv_errsize	= ELAST + 1,
 	.sv_errtbl	= linux_errtbl,
 	.sv_transtrap	= linux_translate_traps,
 	.sv_fixup	= linux_fixup_elf,
 	.sv_sendsig	= linux_sendsig,
 	.sv_sigcode	= &_binary_linux32_locore_o_start,
 	.sv_szsigcode	= &linux_szsigcode,
 	.sv_name	= "Linux ELF32",
 	.sv_coredump	= elf32_coredump,
 	.sv_imgact_try	= linux_exec_imgact_try,
 	.sv_minsigstksz	= LINUX_MINSIGSTKSZ,
 	.sv_pagesize	= PAGE_SIZE,
 	.sv_minuser	= VM_MIN_ADDRESS,
 	.sv_maxuser	= LINUX32_MAXUSER,
 	.sv_usrstack	= LINUX32_USRSTACK,
 	.sv_psstrings	= LINUX32_PS_STRINGS,
 	.sv_stackprot	= VM_PROT_ALL,
 	.sv_copyout_strings = linux_copyout_strings,
 	.sv_setregs	= linux_exec_setregs,
 	.sv_fixlimit	= linux32_fixlimit,
 	.sv_maxssiz	= &linux32_maxssiz,
 	.sv_flags	= SV_ABI_LINUX | SV_ILP32 | SV_IA32 | SV_SHP,
 	.sv_set_syscall_retval = cpu_set_syscall_retval,
 	.sv_fetch_syscall_args = linux32_fetch_syscall_args,
 	.sv_syscallnames = NULL,
 	.sv_shared_page_base = LINUX32_SHAREDPAGE,
 	.sv_shared_page_len = PAGE_SIZE,
 	.sv_schedtail	= linux_schedtail,
 	.sv_thread_detach = linux_thread_detach,
 	.sv_trap	= NULL,
 };
 
 static void
 linux_vdso_install(void *param)
 {
 
 	linux_szsigcode = (&_binary_linux32_locore_o_end -
 	    &_binary_linux32_locore_o_start);
 
 	if (linux_szsigcode > elf_linux_sysvec.sv_shared_page_len)
 		panic("Linux invalid vdso size\n");
 
 	__elfN(linux_vdso_fixup)(&elf_linux_sysvec);
 
 	linux_shared_page_obj = __elfN(linux_shared_page_init)
 	    (&linux_shared_page_mapping);
 
 	__elfN(linux_vdso_reloc)(&elf_linux_sysvec);
 
 	bcopy(elf_linux_sysvec.sv_sigcode, linux_shared_page_mapping,
 	    linux_szsigcode);
 	elf_linux_sysvec.sv_shared_page_obj = linux_shared_page_obj;
 
 	linux_kplatform = linux_shared_page_mapping +
 	    (linux_platform - (caddr_t)elf_linux_sysvec.sv_shared_page_base);
 }
 SYSINIT(elf_linux_vdso_init, SI_SUB_EXEC, SI_ORDER_ANY,
     linux_vdso_install, NULL);
 
 static void
 linux_vdso_deinstall(void *param)
 {
 
 	__elfN(linux_shared_page_fini)(linux_shared_page_obj);
 }
 SYSUNINIT(elf_linux_vdso_uninit, SI_SUB_EXEC, SI_ORDER_FIRST,
     linux_vdso_deinstall, NULL);
 
 static char GNU_ABI_VENDOR[] = "GNU";
 static int GNULINUX_ABI_DESC = 0;
 
 static bool
 linux32_trans_osrel(const Elf_Note *note, int32_t *osrel)
 {
 	const Elf32_Word *desc;
 	uintptr_t p;
 
 	p = (uintptr_t)(note + 1);
 	p += roundup2(note->n_namesz, sizeof(Elf32_Addr));
 
 	desc = (const Elf32_Word *)p;
 	if (desc[0] != GNULINUX_ABI_DESC)
 		return (false);
 
 	/*
 	 * For Linux we encode osrel using the Linux convention of
 	 * 	(version << 16) | (major << 8) | (minor)
 	 * See macro in linux_mib.h
 	 */
 	*osrel = LINUX_KERNVER(desc[1], desc[2], desc[3]);
 
 	return (true);
 }
 
 static Elf_Brandnote linux32_brandnote = {
 	.hdr.n_namesz	= sizeof(GNU_ABI_VENDOR),
 	.hdr.n_descsz	= 16,	/* XXX at least 16 */
 	.hdr.n_type	= 1,
 	.vendor		= GNU_ABI_VENDOR,
 	.flags		= BN_TRANSLATE_OSREL,
 	.trans_osrel	= linux32_trans_osrel
 };
 
 static Elf32_Brandinfo linux_brand = {
 	.brand		= ELFOSABI_LINUX,
 	.machine	= EM_386,
 	.compat_3_brand	= "Linux",
 	.emul_path	= "/compat/linux",
 	.interp_path	= "/lib/ld-linux.so.1",
 	.sysvec		= &elf_linux_sysvec,
 	.interp_newpath	= NULL,
 	.brand_note	= &linux32_brandnote,
 	.flags		= BI_CAN_EXEC_DYN | BI_BRAND_NOTE
 };
 
 static Elf32_Brandinfo linux_glibc2brand = {
 	.brand		= ELFOSABI_LINUX,
 	.machine	= EM_386,
 	.compat_3_brand	= "Linux",
 	.emul_path	= "/compat/linux",
 	.interp_path	= "/lib/ld-linux.so.2",
 	.sysvec		= &elf_linux_sysvec,
 	.interp_newpath	= NULL,
 	.brand_note	= &linux32_brandnote,
 	.flags		= BI_CAN_EXEC_DYN | BI_BRAND_NOTE
 };
 
 static Elf32_Brandinfo linux_muslbrand = {
 	.brand		= ELFOSABI_LINUX,
 	.machine	= EM_386,
 	.compat_3_brand	= "Linux",
 	.emul_path	= "/compat/linux",
 	.interp_path	= "/lib/ld-musl-i386.so.1",
 	.sysvec		= &elf_linux_sysvec,
 	.interp_newpath	= NULL,
 	.brand_note	= &linux32_brandnote,
 	.flags		= BI_CAN_EXEC_DYN | BI_BRAND_NOTE
 };
 
 Elf32_Brandinfo *linux_brandlist[] = {
 	&linux_brand,
 	&linux_glibc2brand,
 	&linux_muslbrand,
 	NULL
 };
 
 static int
 linux_elf_modevent(module_t mod, int type, void *data)
 {
 	Elf32_Brandinfo **brandinfo;
 	int error;
 	struct linux_ioctl_handler **lihp;
 
 	error = 0;
 
 	switch(type) {
 	case MOD_LOAD:
 		for (brandinfo = &linux_brandlist[0]; *brandinfo != NULL;
 		     ++brandinfo)
 			if (elf32_insert_brand_entry(*brandinfo) < 0)
 				error = EINVAL;
 		if (error == 0) {
 			SET_FOREACH(lihp, linux_ioctl_handler_set)
 				linux32_ioctl_register_handler(*lihp);
 			LIST_INIT(&futex_list);
 			mtx_init(&futex_mtx, "ftllk", NULL, MTX_DEF);
 			stclohz = (stathz ? stathz : hz);
 			if (bootverbose)
 				printf("Linux ELF exec handler installed\n");
 		} else
 			printf("cannot insert Linux ELF brand handler\n");
 		break;
 	case MOD_UNLOAD:
 		for (brandinfo = &linux_brandlist[0]; *brandinfo != NULL;
 		     ++brandinfo)
 			if (elf32_brand_inuse(*brandinfo))
 				error = EBUSY;
 		if (error == 0) {
 			for (brandinfo = &linux_brandlist[0];
 			     *brandinfo != NULL; ++brandinfo)
 				if (elf32_remove_brand_entry(*brandinfo) < 0)
 					error = EINVAL;
 		}
 		if (error == 0) {
 			SET_FOREACH(lihp, linux_ioctl_handler_set)
 				linux32_ioctl_unregister_handler(*lihp);
 			mtx_destroy(&futex_mtx);
 			if (bootverbose)
 				printf("Linux ELF exec handler removed\n");
 		} else
 			printf("Could not deinstall ELF interpreter entry\n");
 		break;
 	default:
 		return (EOPNOTSUPP);
 	}
 	return (error);
 }
 
 static moduledata_t linux_elf_mod = {
 	"linuxelf",
 	linux_elf_modevent,
 	0
 };
 
 DECLARE_MODULE_TIED(linuxelf, linux_elf_mod, SI_SUB_EXEC, SI_ORDER_ANY);
 MODULE_DEPEND(linuxelf, linux_common, 1, 1, 1);
 FEATURE(linux, "Linux 32bit support");