5 files changed, 349 insertions, 153 deletions

diff --git a/sys/compat/ia32/ia32_genassym.c b/sys/compat/ia32/ia32_genassym.c
new file mode 100644
index 0000000000000..2134a4477c45c
--- /dev/null
+++ b/sys/compat/ia32/ia32_genassym.c
@@ -0,0 +1,24 @@
+/* $FreeBSD$ */
+
+#include "opt_compat.h"
+
+#include <sys/param.h>
+#include <sys/assym.h>
+#include <sys/systm.h>
+#include <sys/signal.h>
+
+#include <amd64/ia32/ia32_signal.h>
+
+ASSYM(IA32_SIGF_HANDLER, offsetof(struct ia32_sigframe, sf_ah));
+ASSYM(IA32_SIGF_UC, offsetof(struct ia32_sigframe, sf_uc));
+ASSYM(IA32_UC_GS, offsetof(struct ia32_ucontext, uc_mcontext.mc_gs));
+ASSYM(IA32_UC_FS, offsetof(struct ia32_ucontext, uc_mcontext.mc_fs));
+ASSYM(IA32_UC_ES, offsetof(struct ia32_ucontext, uc_mcontext.mc_es));
+ASSYM(IA32_UC_DS, offsetof(struct ia32_ucontext, uc_mcontext.mc_ds));
+#ifdef COMPAT_FREEBSD4
+ASSYM(IA32_SIGF_UC4, offsetof(struct ia32_sigframe, sf_uc));
+ASSYM(IA32_UC4_GS, offsetof(struct ia32_ucontext4, uc_mcontext.mc_gs));
+ASSYM(IA32_UC4_FS, offsetof(struct ia32_ucontext4, uc_mcontext.mc_fs));
+ASSYM(IA32_UC4_ES, offsetof(struct ia32_ucontext4, uc_mcontext.mc_es));
+ASSYM(IA32_UC4_DS, offsetof(struct ia32_ucontext4, uc_mcontext.mc_ds));
+#endif
diff --git a/sys/compat/ia32/ia32_signal.h b/sys/compat/ia32/ia32_signal.h
new file mode 100644
index 0000000000000..f251e72fb33c5
--- /dev/null
+++ b/sys/compat/ia32/ia32_signal.h
@@ -0,0 +1,164 @@
+/*-
+ * Copyright (c) 1999 Marcel Moolenaar
+ * Copyright (c) 2003 Peter Wemm
+ * 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.
+ *
+ * $FreeBSD$
+ */
+
+struct ia32_sigaltstack {
+	u_int32_t	ss_sp;		/* signal stack base */
+	u_int32_t	ss_size;	/* signal stack length */
+	int		ss_flags;	/* SS_DISABLE and/or SS_ONSTACK */
+};
+
+/* XXX should be 640 bytes long; check and see if __packed is needed */
+struct ia32_mcontext {
+	int	mc_onstack;		/* XXX - sigcontext compat. */
+	int	mc_gs;			/* machine state (struct trapframe) */
+	int	mc_fs;
+	int	mc_es;
+	int	mc_ds;
+	int	mc_edi;
+	int	mc_esi;
+	int	mc_ebp;
+	int	mc_isp;
+	int	mc_ebx;
+	int	mc_edx;
+	int	mc_ecx;
+	int	mc_eax;
+	int	mc_trapno;
+	int	mc_err;
+	int	mc_eip;
+	int	mc_cs;
+	int	mc_eflags;
+	int	mc_esp;
+	int	mc_ss;
+	int	mc_len;			/* sizeof(struct ia32_mcontext) */
+	/* We use the same values for fpformat and ownedfp */
+	int	mc_fpformat;
+	int	mc_ownedfp;
+	int	mc_spare1[1];		/* align next field to 16 bytes */
+	/*
+	 * See <machine/npx.h> for the internals of mc_fpstate[].
+	 */
+	int	mc_fpstate[128] __aligned(16);
+	int	mc_spare2[8];
+};
+
+/* XXX should be 704 bytes long; check and see if __packed is needed */
+struct ia32_ucontext {
+	sigset_t		uc_sigmask;
+	struct ia32_mcontext	uc_mcontext;
+	u_int32_t		uc_link;
+	struct ia32_sigaltstack	uc_stack;
+	int			uc_flags;
+	int			__spare__[4];
+};
+
+
+#if defined(COMPAT_FREEBSD4)
+struct ia32_mcontext4 {
+	int	mc_onstack;		/* XXX - sigcontext compat. */
+	int	mc_gs;			/* machine state (struct trapframe) */
+	int	mc_fs;
+	int	mc_es;
+	int	mc_ds;
+	int	mc_edi;
+	int	mc_esi;
+	int	mc_ebp;
+	int	mc_isp;
+	int	mc_ebx;
+	int	mc_edx;
+	int	mc_ecx;
+	int	mc_eax;
+	int	mc_trapno;
+	int	mc_err;
+	int	mc_eip;
+	int	mc_cs;
+	int	mc_eflags;
+	int	mc_esp;	
+	int	mc_ss;
+	int	mc_fpregs[28];
+	int	__spare__[17];
+};
+
+struct ia32_ucontext4 {
+	sigset_t		uc_sigmask;
+	struct ia32_mcontext4	uc_mcontext;
+	u_int32_t		uc_link;
+	struct ia32_sigaltstack	uc_stack;
+	int			__spare__[8];
+};
+#endif
+
+/*
+ * Signal frames, arguments passed to application signal handlers.
+ */
+union ia32_sigval {
+	int			sigval_int;
+	u_int32_t		sigval_ptr;
+};
+struct ia32_siginfo {
+	int			si_signo;	/* signal number */
+	int			si_errno;	/* errno association */
+	int			si_code;	/* signal code */
+	int32_t			si_pid;		/* sending process */
+	u_int32_t		si_uid;		/* sender's ruid */
+	int			si_status;	/* exit value */
+	u_int32_t		si_addr;	/* faulting instruction */
+	union ia32_sigval	si_value;	/* signal value */
+	int32_t			si_band;	/* band event for SIGPOLL */
+	int			__spare__[7];	/* gimme some slack */
+};
+
+#ifdef COMPAT_FREEBSD4
+struct ia32_sigframe4 {
+	u_int32_t		sf_signum;
+	u_int32_t		sf_siginfo;	/* code or pointer to sf_si */
+	u_int32_t		sf_ucontext;	/* points to sf_uc */
+	u_int32_t		sf_addr;	/* undocumented 4th arg */
+	u_int32_t		sf_ah;		/* action/handler pointer */
+	struct ia32_ucontext4	sf_uc;		/* = *sf_ucontext */
+	struct ia32_siginfo	sf_si;		/* = *sf_siginfo (SA_SIGINFO case) */
+};
+#endif
+
+struct ia32_sigframe {
+	u_int32_t		sf_signum;
+	u_int32_t		sf_siginfo;	/* code or pointer to sf_si */
+	u_int32_t		sf_ucontext;	/* points to sf_uc */
+	u_int32_t		sf_addr;	/* undocumented 4th arg */
+	u_int32_t		sf_ah;		/* action/handler pointer */
+	struct ia32_ucontext	sf_uc;		/* = *sf_ucontext */
+	struct ia32_siginfo	sf_si;		/* = *sf_siginfo (SA_SIGINFO case) */
+};
+
+extern char ia32_sigcode[];
+extern char freebsd4_ia32_sigcode[];
+extern int sz_ia32_sigcode;
+extern int sz_freebsd4_ia32_sigcode;
+extern void ia32_sendsig(sig_t, int, sigset_t *, u_long);
diff --git a/sys/compat/ia32/ia32_sigtramp.S b/sys/compat/ia32/ia32_sigtramp.S
new file mode 100644
index 0000000000000..2e9f73d41bcee
--- /dev/null
+++ b/sys/compat/ia32/ia32_sigtramp.S
@@ -0,0 +1,87 @@
+/*-
+ * Copyright (c) 2003 Peter Wemm
+ * 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.
+ * 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.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``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 OR CONTRIBUTORS 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.
+ *
+ * $FreeBSD$
+ */
+
+#include "opt_compat.h"
+
+#include <machine/asmacros.h>
+#include <sys/syscall.h>
+
+#include "ia32_assym.h"
+
+	.text
+	.code32
+/*
+ * Signal trampoline, copied to top of user stack
+ */
+	ALIGN_TEXT
+	.globl	ia32_sigcode
+ia32_sigcode:
+	calll	*IA32_SIGF_HANDLER(%esp)
+	leal	IA32_SIGF_UC(%esp),%eax	/* get ucontext */
+	pushl	%eax
+	movl	IA32_UC_GS(%eax),%gs	/* restore %gs */
+	movl	IA32_UC_FS(%eax),%fs	/* restore %fs */
+	movl	IA32_UC_ES(%eax),%es	/* restore %es */
+	movl	IA32_UC_DS(%eax),%ds	/* restore %ds */
+	movl	$SYS_sigreturn,%eax
+	pushl	%eax			/* junk to fake return addr. */
+	int	$0x80			/* enter kernel with args */
+					/* on stack */
+1:
+	jmp	1b
+
+#ifdef COMPAT_FREEBSD4
+	ALIGN_TEXT
+freebsd4_ia32_sigcode:
+	calll	*IA32_SIGF_HANDLER(%esp)
+	leal	IA32_SIGF_UC4(%esp),%eax/* get ucontext */
+	pushl	%eax
+	movl	IA32_UC4_GS(%eax),%gs	/* restore %gs */
+	movl	IA32_UC4_FS(%eax),%fs	/* restore %fs */
+	movl	IA32_UC4_ES(%eax),%es	/* restore %es */
+	movl	IA32_UC4_DS(%eax),%ds	/* restore %ds */
+	movl	$344,%eax		/* 4.x SYS_sigreturn */
+	pushl	%eax			/* junk to fake return addr. */
+	int	$0x80			/* enter kernel with args */
+					/* on stack */
+1:
+	jmp	1b
+#endif
+
+	ALIGN_TEXT
+esigcode:
+
+	.data
+	.globl	sz_ia32_sigcode
+sz_ia32_sigcode:
+	.long	esigcode-ia32_sigcode
+#ifdef COMPAT_FREEBSD4
+	.globl	sz_freebsd4_ia32_sigcode
+sz_freebsd4_ia32_sigcode:
+	.long	esigcode-freebsd4_ia32_sigcode
+#endif
diff --git a/sys/compat/ia32/ia32_sysvec.c b/sys/compat/ia32/ia32_sysvec.c
index 18f4ee2fc78c6..684677a7cf88f 100644
--- a/sys/compat/ia32/ia32_sysvec.c
+++ b/sys/compat/ia32/ia32_sysvec.c
@@ -1,5 +1,6 @@
 /*-
  * Copyright (c) 2002 Doug Rabson
+ * Copyright (c) 2003 Peter Wemm
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -26,6 +27,8 @@
  * $FreeBSD$
  */
 
+#include "opt_compat.h"
+
 #define __ELF_WORD_SIZE 32
 
 #include <sys/param.h>
@@ -60,12 +63,16 @@
 #include <vm/vm_object.h>
 #include <vm/vm_extern.h>
 
-#include <ia64/ia32/ia32_util.h>
-#include <i386/include/psl.h>
-#include <i386/include/segments.h>
-#include <i386/include/specialreg.h>
+#include <amd64/ia32/ia32_util.h>
+#include <amd64/ia32/ia32_proto.h>
+#include <amd64/ia32/ia32_signal.h>
+#include <machine/psl.h>
+#include <machine/segments.h>
+#include <machine/specialreg.h>
 #include <machine/frame.h>
 #include <machine/md_var.h>
+#include <machine/pcb.h>
+#include <machine/cpufunc.h>
 
 static register_t *ia32_copyout_strings(struct image_params *imgp);
 static void ia32_setregs(struct thread *td, u_long entry, u_long stack,
@@ -73,21 +80,6 @@ static void ia32_setregs(struct thread *td, u_long entry, u_long stack,
 
 extern struct sysent ia32_sysent[];
 
-static char ia32_sigcode[] = {
-	0xff, 0x54, 0x24, 0x10,		/* call *SIGF_HANDLER(%esp) */
-	0x8d, 0x44, 0x24, 0x14,		/* lea SIGF_UC(%esp),%eax */
-	0x50,				/* pushl %eax */
-	0xf7, 0x40, 0x54, 0x00, 0x00, 0x02, 0x02, /* testl $PSL_VM,UC_EFLAGS(%eax) */
-	0x75, 0x03,			/* jne 9f */
-	0x8e, 0x68, 0x14,		/* movl UC_GS(%eax),%gs */
-	0xb8, 0x57, 0x01, 0x00, 0x00,	/* 9: movl $SYS_sigreturn,%eax */
-	0x50,				/* pushl %eax */
-	0xcd, 0x80,			/* int $0x80 */
-	0xeb, 0xfe,			/* 0: jmp 0b */
-	0, 0, 0, 0
-};
-static int ia32_szsigcode = sizeof(ia32_sigcode) & ~3;
-
 struct sysentvec ia32_freebsd_sysvec = {
 	SYS_MAXSYSCALL,
 	ia32_sysent,
@@ -98,24 +90,26 @@ struct sysentvec ia32_freebsd_sysvec = {
 	NULL,
 	NULL,
 	elf32_freebsd_fixup,
-	sendsig,
+	ia32_sendsig,
 	ia32_sigcode,
-	&ia32_szsigcode,
+	&sz_ia32_sigcode,
 	NULL,
-	"FreeBSD ELF",
+	"FreeBSD ELF32",
 	elf32_coredump,
 	NULL,
 	MINSIGSTKSZ,
-	4096,
+	PAGE_SIZE,
 	0,
-	IA32_USRSTACK,
-	IA32_USRSTACK,
-	IA32_PS_STRINGS,
+	USRSTACK,
+	USRSTACK,
+	PS_STRINGS,
 	VM_PROT_ALL,
 	ia32_copyout_strings,
 	ia32_setregs
 };
 
+
+
 static Elf32_Brandinfo ia32_brand_info = {
 						ELFOSABI_FREEBSD,
 						EM_386,
@@ -129,6 +123,8 @@ SYSINIT(ia32, SI_SUB_EXEC, SI_ORDER_ANY,
 	(sysinit_cfunc_t) elf32_insert_brand_entry,
 	&ia32_brand_info);
 
+extern int _ucode32sel, _udatasel;
+
 static register_t *
 ia32_copyout_strings(struct image_params *imgp)
 {
@@ -143,7 +139,7 @@ ia32_copyout_strings(struct image_params *imgp)
 	 * Calculate string base and vector table pointers.
 	 * Also deal with signal trampoline code for this exec type.
 	 */
-	arginfo = (struct ia32_ps_strings *)IA32_PS_STRINGS;
+	arginfo = (struct ia32_ps_strings *)PS_STRINGS;
 	szsigcode = *(imgp->proc->p_sysent->sv_szsigcode);
 	destp =	(caddr_t)arginfo - szsigcode - SPARE_USRSPACE -
 		roundup((ARG_MAX - imgp->stringspace), sizeof(char *));
@@ -190,7 +186,6 @@ ia32_copyout_strings(struct image_params *imgp)
 	stringp = imgp->stringbase;
 	argc = imgp->argc;
 	envc = imgp->envc;
-
 	/*
 	 * Copy out strings - arguments and environment.
 	 */
@@ -234,135 +229,61 @@ ia32_copyout_strings(struct image_params *imgp)
 	return ((register_t *)stack_base);
 }
 
-static void
-ia32_setregs(struct thread *td, u_long entry, u_long stack, u_long ps_strings)
+/*
+ * Clear registers on exec
+ */
+void
+ia32_setregs(td, entry, stack, ps_strings)
+	struct thread *td;
+	u_long entry;
+	u_long stack;
+	u_long ps_strings;
 {
-	struct trapframe *frame = td->td_frame;
-	vm_offset_t gdt, ldt;
-	u_int64_t codesel, datasel, ldtsel;
-	u_int64_t codeseg, dataseg, gdtseg, ldtseg;
-	struct segment_descriptor desc;
-	struct vmspace *vmspace = td->td_proc->p_vmspace;
+	struct trapframe *regs = td->td_frame;
+	struct pcb *pcb = td->td_pcb;
+	u_int64_t pc;
+	register_t s;
+	
+	wrmsr(MSR_FSBASE, 0);
+	wrmsr(MSR_KGSBASE, 0);	/* User value while we're in the kernel */
+	pcb->pcb_fsbase = 0;
+	pcb->pcb_gsbase = 0;
+	pcb->pcb_kgsbase = rdmsr(MSR_GSBASE);
+	load_ds(_udatasel);
+	load_es(_udatasel);
+	load_fs(_udatasel);
+	s = intr_disable();
+	pc = rdmsr(MSR_GSBASE);
+	load_gs(_udatasel);	/* Clobbers kernel %GS.base */
+	wrmsr(MSR_GSBASE, pc);
+	intr_restore(s);
+	pcb->pcb_ds = _udatasel;
+	pcb->pcb_es = _udatasel;
+	pcb->pcb_fs = _udatasel;
+	pcb->pcb_gs = _udatasel;
+
+	bzero((char *)regs, sizeof(struct trapframe));
+	regs->tf_rip = entry;
+	regs->tf_rsp = stack;
+	regs->tf_rflags = PSL_USER | (regs->tf_rflags & PSL_T);
+	regs->tf_ss = _udatasel;
+	regs->tf_cs = _ucode32sel;
+	regs->tf_rbx = ps_strings;
 
 	/*
-	 * Make sure that we restore the entire trapframe after an
-	 * execve.
+	 * Arrange to trap the next npx or `fwait' instruction (see npx.c
+	 * for why fwait must be trapped at least if there is an npx or an
+	 * emulator).  This is mainly to handle the case where npx0 is not
+	 * configured, since the npx routines normally set up the trap
+	 * otherwise.  It should be done only at boot time, but doing it
+	 * here allows modifying `npx_exists' for testing the emulator on
+	 * systems with an npx.
 	 */
-	frame->tf_flags &= ~FRAME_SYSCALL;
-
-	bzero(frame->tf_r, sizeof(frame->tf_r));
-	bzero(frame->tf_f, sizeof(frame->tf_f));
-
-	frame->tf_cr_iip = entry;
-	frame->tf_cr_ipsr = (IA64_PSR_IC
-			     | IA64_PSR_I
-			     | IA64_PSR_IT
-			     | IA64_PSR_DT
-			     | IA64_PSR_RT
-			     | IA64_PSR_DFH
-			     | IA64_PSR_IS
-			     | IA64_PSR_BN
-			     | IA64_PSR_CPL_USER);
-	frame->tf_r[FRAME_R12] = stack;
-
-	codesel = LSEL(LUCODE_SEL, SEL_UPL);
-	datasel = LSEL(LUDATA_SEL, SEL_UPL);
-	ldtsel = GSEL(GLDT_SEL, SEL_UPL);
-
-#if 1
-	frame->tf_r[FRAME_R16] = (datasel << 48) | (datasel << 32)
-		| (datasel << 16) | datasel;
-	frame->tf_r[FRAME_R17] = (ldtsel << 32) | (datasel << 16) | codesel;
-#else
-	frame->tf_r[FRAME_R16] = datasel;
-	frame->tf_r[FRAME_R17] = codesel;
-	frame->tf_r[FRAME_R18] = datasel;
-	frame->tf_r[FRAME_R19] = datasel;
-	frame->tf_r[FRAME_R20] = datasel;
-	frame->tf_r[FRAME_R21] = datasel;
-	frame->tf_r[FRAME_R22] = ldtsel;
-#endif
+	load_cr0(rcr0() | CR0_MP | CR0_TS);
 
-	/*
-	 * Build the GDT and LDT.
-	 */
-	gdt = IA32_USRSTACK;
-	vm_map_find(&vmspace->vm_map, 0, 0,
-		    &gdt, PAGE_SIZE, 0,
-		    VM_PROT_ALL, VM_PROT_ALL, 0);
-	ldt = gdt + 4096;
-
-	desc.sd_lolimit = 8*NLDT-1;
-	desc.sd_lobase = ldt & 0xffffff;
-	desc.sd_type = SDT_SYSLDT;
-	desc.sd_dpl = SEL_UPL;
-	desc.sd_p = 1;
-	desc.sd_hilimit = 0;
-	desc.sd_def32 = 0;
-	desc.sd_gran = 0;
-	desc.sd_hibase = ldt >> 24;
-	copyout(&desc, (caddr_t) gdt + 8*GLDT_SEL, sizeof(desc));
-
-	desc.sd_lolimit = ((IA32_USRSTACK >> 12) - 1) & 0xffff;
-	desc.sd_lobase = 0;
-	desc.sd_type = SDT_MEMERA;
-	desc.sd_dpl = SEL_UPL;
-	desc.sd_p = 1;
-	desc.sd_hilimit = ((IA32_USRSTACK >> 12) - 1) >> 16;
-	desc.sd_def32 = 1;
-	desc.sd_gran = 1;
-	desc.sd_hibase = 0;
-	copyout(&desc, (caddr_t) ldt + 8*LUCODE_SEL, sizeof(desc));
-	desc.sd_type = SDT_MEMRWA;
-	copyout(&desc, (caddr_t) ldt + 8*LUDATA_SEL, sizeof(desc));
-
-	codeseg = 0		/* base */
-		+ (((IA32_USRSTACK >> 12) - 1) << 32) /* limit */
-		+ ((long)SDT_MEMERA << 52)
-		+ ((long)SEL_UPL << 57)
-		+ (1L << 59) /* present */
-		+ (1L << 62) /* 32 bits */
-		+ (1L << 63); /* page granularity */
-	dataseg = 0		/* base */
-		+ (((IA32_USRSTACK >> 12) - 1) << 32) /* limit */
-		+ ((long)SDT_MEMRWA << 52)
-		+ ((long)SEL_UPL << 57)
-		+ (1L << 59) /* present */
-		+ (1L << 62) /* 32 bits */
-		+ (1L << 63); /* page granularity */
-	ia64_set_csd(codeseg);
-	ia64_set_ssd(dataseg);
-	frame->tf_r[FRAME_R24] = dataseg; /* ESD */
-	frame->tf_r[FRAME_R27] = dataseg; /* DSD */
-	frame->tf_r[FRAME_R28] = dataseg; /* FSD */
-	frame->tf_r[FRAME_R29] = dataseg; /* GSD */
-
-	gdtseg = gdt		/* base */
-		+ ((8L*NGDT - 1) << 32) /* limit */
-		+ ((long)SDT_SYSNULL << 52)
-		+ ((long)SEL_UPL << 57)
-		+ (1L << 59) /* present */
-		+ (0L << 62) /* 16 bits */
-		+ (0L << 63); /* byte granularity */
-	ldtseg = ldt		/* base */
-		+ ((8L*NLDT - 1) << 32) /* limit */
-		+ ((long)SDT_SYSLDT << 52)
-		+ ((long)SEL_UPL << 57)
-		+ (1L << 59) /* present */
-		+ (0L << 62) /* 16 bits */
-		+ (0L << 63); /* byte granularity */
-	frame->tf_r[FRAME_R30] = ldtseg; /* LDTD */
-	frame->tf_r[FRAME_R31] = gdtseg; /* GDTD */
-
-	ia64_set_eflag(PSL_USER);
-
-	/* PS_STRINGS value for BSD/OS binaries.  It is 0 for non-BSD/OS. */
-	frame->tf_r[FRAME_R11] = IA32_PS_STRINGS;
+	fpstate_drop(td);
 
-	/*
-	 * XXX - Linux emulator
-	 * Make sure sure edx is 0x0 on entry. Linux binaries depend
-	 * on it.
-	 */
+	/* Return via doreti so that we can change to a different %cs */
+	pcb->pcb_flags |= PCB_FULLCTX;
 	td->td_retval[1] = 0;
 }
diff --git a/sys/compat/ia32/ia32_util.h b/sys/compat/ia32/ia32_util.h
index 23f2abae1ab2d..20a5b1e284160 100644
--- a/sys/compat/ia32/ia32_util.h
+++ b/sys/compat/ia32/ia32_util.h
@@ -44,7 +44,7 @@ struct ia32_ps_strings {
 	int	ps_nenvstr;	/* the number of environment strings */
 };
 
-#define IA32_USRSTACK	(4L*1024*1024*1024 - PAGE_SIZE)
+#define IA32_USRSTACK	USRSTACK
 #define IA32_PS_STRINGS	(IA32_USRSTACK - sizeof(struct ia32_ps_strings))
 
 static __inline caddr_t stackgap_init(void);