Maintain %f and %gs over traps. Mostly from NetBSD. Preparation for SMP

speedups.

14 files changed, 94 insertions, 140 deletions

diff --git a/sys/arch/i386/i386/db_interface.c b/sys/arch/i386/i386/db_interface.c
index 5ee659efcbb..bbf7a09c6bc 100644
--- a/sys/arch/i386/i386/db_interface.c
+++ b/sys/arch/i386/i386/db_interface.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: db_interface.c,v 1.14 2004/06/21 22:41:11 andreas Exp $	*/
+/*	$OpenBSD: db_interface.c,v 1.15 2004/07/02 16:29:55 niklas Exp $	*/
 /*	$NetBSD: db_interface.c,v 1.22 1996/05/03 19:42:00 christos Exp $	*/
 
 /* 
@@ -144,6 +144,8 @@ kdb_trap(type, code, regs)
 	db_active--;
 	splx(s);
 
+	regs->tf_fs     = ddb_regs.tf_fs & 0xffff;
+	regs->tf_gs     = ddb_regs.tf_gs & 0xffff;
 	regs->tf_es     = ddb_regs.tf_es & 0xffff;
 	regs->tf_ds     = ddb_regs.tf_ds & 0xffff;
 	regs->tf_edi    = ddb_regs.tf_edi;
diff --git a/sys/arch/i386/i386/db_trace.c b/sys/arch/i386/i386/db_trace.c
index 40ea010c316..a552cc883e9 100644
--- a/sys/arch/i386/i386/db_trace.c
+++ b/sys/arch/i386/i386/db_trace.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: db_trace.c,v 1.9 2003/05/20 09:51:22 andreas Exp $	*/
+/*	$OpenBSD: db_trace.c,v 1.10 2004/07/02 16:29:55 niklas Exp $	*/
 /*	$NetBSD: db_trace.c,v 1.18 1996/05/03 19:42:01 christos Exp $	*/
 
 /* 
@@ -43,8 +43,10 @@
  * Machine register set.
  */
 struct db_variable db_regs[] = {
-	{ "es",		(long *)&ddb_regs.tf_es,     FCN_NULL },
 	{ "ds",		(long *)&ddb_regs.tf_ds,     FCN_NULL },
+	{ "es",		(long *)&ddb_regs.tf_es,     FCN_NULL },
+	{ "fs",		(long *)&ddb_regs.tf_fs,     FCN_NULL },
+	{ "gs",		(long *)&ddb_regs.tf_gs,     FCN_NULL },
 	{ "edi",	(long *)&ddb_regs.tf_edi,    FCN_NULL },
 	{ "esi",	(long *)&ddb_regs.tf_esi,    FCN_NULL },
 	{ "ebp",	(long *)&ddb_regs.tf_ebp,    FCN_NULL },
diff --git a/sys/arch/i386/i386/genassym.cf b/sys/arch/i386/i386/genassym.cf
index c29811bf5e1..7453c773fed 100644
--- a/sys/arch/i386/i386/genassym.cf
+++ b/sys/arch/i386/i386/genassym.cf
@@ -1,4 +1,4 @@
-#	$OpenBSD: genassym.cf,v 1.16 2004/06/28 02:00:20 deraadt Exp $
+#	$OpenBSD: genassym.cf,v 1.17 2004/07/02 16:29:55 niklas Exp $
 #
 # Copyright (c) 1982, 1990 The Regents of the University of California.
 # All rights reserved.
@@ -103,8 +103,6 @@ struct	pcb
 member	pcb_cr3
 member	pcb_ebp
 member	pcb_esp
-member	pcb_fs
-member	pcb_gs
 member	pcb_cr0
 member	pcb_ldt_sel
 member	pcb_onfault
@@ -126,9 +124,6 @@ struct	sigframe	SIGF_
 member	HANDLER		sf_handler
 member	SC		sf_sc
 struct	sigcontext
-member	sc_fs
-member	sc_gs
-member	sc_eflags
 
 # mbuf fields
 ifdef INET
@@ -144,9 +139,6 @@ struct	svr4_sigframe	SVR4_SIGF_
 member	HANDLER		sf_handler
 member	UC		sf_uc
 struct	svr4_ucontext	SVR4_UC_
-member	FS		uc_mcontext.greg[SVR4_X86_FS]
-member	GS		uc_mcontext.greg[SVR4_X86_GS]
-member	EFLAGS		uc_mcontext.greg[SVR4_X86_EFL]
 endif
 
 # Linux frame offsets
@@ -155,9 +147,6 @@ struct	linux_sigframe		LINUX_SIGF_
 member	HANDLER			sf_handler
 member	SC			sf_sc
 struct	linux_sigcontext	LINUX_
-member	sc_fs			
-member	sc_gs
-member	sc_eflags
 endif
 
 # FreeBSD frame offsets
diff --git a/sys/arch/i386/i386/kgdb_machdep.c b/sys/arch/i386/i386/kgdb_machdep.c
index fc74f997647..3e926ecf4f4 100644
--- a/sys/arch/i386/i386/kgdb_machdep.c
+++ b/sys/arch/i386/i386/kgdb_machdep.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: kgdb_machdep.c,v 1.2 2001/11/06 19:53:14 miod Exp $	*/
+/*	$OpenBSD: kgdb_machdep.c,v 1.3 2004/07/02 16:29:55 niklas Exp $	*/
 /*	$NetBSD: kgdb_machdep.c,v 1.6 1998/08/13 21:36:03 thorpej Exp $	*/
 
 /*-
@@ -181,6 +181,8 @@ kgdb_getregs(regs, gdb_regs)
 	gdb_regs[10] = regs->tf_cs;
 	gdb_regs[12] = regs->tf_ds;
 	gdb_regs[13] = regs->tf_es;
+	gdb_regs[14] = regs->tf_fs;
+	gdb_regs[15] = regs->tf_gs;
 
 	if (KERNELMODE(regs->tf_cs, regs->tf_eflags)) {
 		/*
diff --git a/sys/arch/i386/i386/linux_machdep.c b/sys/arch/i386/i386/linux_machdep.c
index 5e4abf72251..46cd7f6ffe9 100644
--- a/sys/arch/i386/i386/linux_machdep.c
+++ b/sys/arch/i386/i386/linux_machdep.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: linux_machdep.c,v 1.29 2003/08/15 20:32:13 tedu Exp $	*/
+/*	$OpenBSD: linux_machdep.c,v 1.30 2004/07/02 16:29:55 niklas Exp $	*/
 /*	$NetBSD: linux_machdep.c,v 1.29 1996/05/03 19:42:11 christos Exp $	*/
 
 /*
@@ -150,8 +150,8 @@ linux_sendsig(catcher, sig, mask, code, type, val)
 	} else
 #endif
 	{
-		__asm("movl %%gs,%k0" : "=r" (frame.sf_sc.sc_gs));
-		__asm("movl %%fs,%k0" : "=r" (frame.sf_sc.sc_fs));
+		frame.sf_sc.sc_fs = tf->tf_fs;
+		frame.sf_sc.sc_gs = tf->tf_gs;
 		frame.sf_sc.sc_es = tf->tf_es;
 		frame.sf_sc.sc_ds = tf->tf_ds;
 		frame.sf_sc.sc_eflags = tf->tf_eflags;
@@ -248,7 +248,8 @@ linux_sys_sigreturn(p, v, retval)
 		    !USERMODE(context.sc_cs, context.sc_eflags))
 			return (EINVAL);
 
-		/* %fs and %gs were restored by the trampoline. */
+		tf->tf_fs = context.sc_fs;
+		tf->tf_gs = context.sc_gs;
 		tf->tf_es = context.sc_es;
 		tf->tf_ds = context.sc_ds;
 		tf->tf_eflags = context.sc_eflags;
diff --git a/sys/arch/i386/i386/locore.s b/sys/arch/i386/i386/locore.s
index c738cee27c1..8686395cce3 100644
--- a/sys/arch/i386/i386/locore.s
+++ b/sys/arch/i386/i386/locore.s
@@ -1,4 +1,4 @@
-/*	$OpenBSD: locore.s,v 1.78 2004/06/13 21:49:15 niklas Exp $	*/
+/*	$OpenBSD: locore.s,v 1.79 2004/07/02 16:29:55 niklas Exp $	*/
 /*	$NetBSD: locore.s,v 1.145 1996/05/03 19:41:19 christos Exp $	*/
 
 /*-
@@ -153,10 +153,17 @@
 	pushl	%edi		; \
 	pushl	%ds		; \
 	pushl	%es		; \
+	pushl	%gs		; \
 	movl	$GSEL(GDATA_SEL, SEL_KPL),%eax	; \
 	movw	%ax,%ds		; \
-	movw	%ax,%es
+	movw	%ax,%es		; \
+	movw	%ax,%gs		; \
+	pushl	%fs		; \
+	movl	$GSEL(GCPU_SEL, SEL_KPL),%eax	; \
+	movw	%ax,%fs
 #define	INTRFASTEXIT \
+	popl	%fs		; \
+	popl	%gs		; \
 	popl	%es		; \
 	popl	%ds		; \
 	popl	%edi		; \
@@ -295,6 +302,11 @@ start:	movw	$0x1234,0x472			# warm boot
 	pushl	$PSL_MBO
 	popfl
 
+	/* Clear segment registers; always null in proc0. */
+	xorl	%eax,%eax
+	movw	%ax,%fs
+	movw	%ax,%gs
+
 	/* Find out our CPU type. */
 
 try386:	/* Try to toggle alignment check flag; does not exist on 386. */
@@ -704,11 +716,6 @@ begin:
 	call	_C_LABEL(init386)	# wire 386 chip for unix operation
 	addl	$4,%esp
 
-	/* Clear segment registers; always null in proc0. */
-	xorl	%ecx,%ecx
-	movw	%cx,%fs
-	movw	%cx,%gs
-
 	call	_C_LABEL(main)
 
 NENTRY(proc_trampoline)
@@ -731,15 +738,7 @@ NENTRY(sigcode)
 	call	*SIGF_HANDLER(%esp)
 	leal	SIGF_SC(%esp),%eax	# scp (the call may have clobbered the
 					# copy at SIGF_SCP(%esp))
-#ifdef VM86
-	testl	$PSL_VM,SC_EFLAGS(%eax)
-	jnz	1f
-#endif
-	movl	SC_FS(%eax),%ecx
-	movl	SC_GS(%eax),%edx
-	movw	%cx,%fs
-	movw	%dx,%gs
-1:	pushl	%eax
+	pushl	%eax
 	pushl	%eax			# junk to fake return address
 	movl	$SYS_sigreturn,%eax
 	int	$0x80			# enter kernel with args on stack
@@ -755,15 +754,7 @@ NENTRY(svr4_sigcode)
 	call	*SVR4_SIGF_HANDLER(%esp)
 	leal	SVR4_SIGF_UC(%esp),%eax	# ucp (the call may have clobbered the
 					# copy at SIGF_UCP(%esp))
-#ifdef VM86
-	testl	$PSL_VM,SVR4_UC_EFLAGS(%eax)
-	jnz	1f
-#endif
-	movl	SVR4_UC_FS(%eax),%ecx
-	movl	SVR4_UC_GS(%eax),%edx
-	movw	%cx,%fs
-	movw	%dx,%gs
-1:	pushl	%eax
+	pushl	%eax
 	pushl	$1			# setcontext(p) == syscontext(1, p)
 	pushl	%eax			# junk to fake return address
 	movl	$SVR4_SYS_context,%eax
@@ -784,15 +775,7 @@ NENTRY(linux_sigcode)
 	call	*LINUX_SIGF_HANDLER(%esp)
 	leal	LINUX_SIGF_SC(%esp),%ebx # scp (the call may have clobbered the
 					# copy at SIGF_SCP(%esp))
-#ifdef VM86
-	testl	$PSL_VM,LINUX_SC_EFLAGS(%ebx)
-	jnz	1f
-#endif
-	movl	LINUX_SC_FS(%ebx),%ecx
-	movl	LINUX_SC_GS(%ebx),%edx
-	movw	%cx,%fs
-	movw	%dx,%gs
-1:	pushl	%eax			# junk to fake return address
+	pushl	%eax			# junk to fake return address
 	movl	$LINUX_SYS_sigreturn,%eax
 	int	$0x80			# enter kernel with args on stack
 	movl	$LINUX_SYS_exit,%eax
@@ -1749,16 +1732,6 @@ switch_search:
 
 	movl	P_ADDR(%esi),%esi
 
-	/* Save segment registers. */
-#ifdef DDB
-	xorl	%eax, %eax
-	xorl	%ecx, %ecx
-#endif
-	movw	%fs,%ax
-	movw	%gs,%cx
-	movl	%eax,PCB_FS(%esi)
-	movl	%ecx,PCB_GS(%esi)
-
 	/* Save stack pointers. */
 	movl	%esp,PCB_ESP(%esi)
 	movl	%ebp,PCB_EBP(%esi)
@@ -1822,12 +1795,6 @@ switch_exited:
 	lldt	%dx
 #endif /* USER_LDT */
 
-	/* Restore segment registers. */
-	movl	PCB_FS(%esi),%eax
-	movl	PCB_GS(%esi),%ecx
-	movw	%ax,%fs
-	movw	%cx,%gs
-
 switch_restored:
 	/* Restore cr0 (including FPU state). */
 	movl	PCB_CR0(%esi),%ecx
@@ -1957,16 +1924,6 @@ ENTRY(switch_exit)
 ENTRY(savectx)
 	movl	4(%esp),%edx		# edx = p->p_addr
 
-	/* Save segment registers. */
-#ifdef DDB
-	xorl	%eax, %eax
-	xorl	%ecx, %ecx
-#endif
-	movw	%fs,%ax
-	movw	%gs,%cx
-	movl	%eax,PCB_FS(%edx)
-	movl	%ecx,PCB_GS(%edx)
-
 	/* Save stack pointers. */
 	movl	%esp,PCB_ESP(%edx)
 	movl	%ebp,PCB_EBP(%edx)
@@ -2108,9 +2065,18 @@ IDTVEC(align)
 NENTRY(resume_iret)
 	ZTRAP(T_PROTFLT)
 NENTRY(resume_pop_ds)
+	pushl	%es
 	movl	$GSEL(GDATA_SEL, SEL_KPL),%eax
 	movw	%ax,%es
 NENTRY(resume_pop_es)
+	pushl	%gs
+	movl	$GSEL(GDATA_SEL, SEL_KPL),%eax
+	movw	%ax,%gs
+NENTRY(resume_pop_gs)
+	pushl	%fs     
+	movl	$GSEL(GDATA_SEL, SEL_KPL),%eax
+	movw	%ax,%fs
+NENTRY(resume_pop_fs)
 	movl	$T_PROTFLT,TF_TRAPNO(%esp)
 	jmp	calltrap
 
diff --git a/sys/arch/i386/i386/machdep.c b/sys/arch/i386/i386/machdep.c
index d4d28d8b55f..89fdc3b9c6d 100644
--- a/sys/arch/i386/i386/machdep.c
+++ b/sys/arch/i386/i386/machdep.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: machdep.c,v 1.302 2004/06/28 20:51:02 deraadt Exp $	*/
+/*	$OpenBSD: machdep.c,v 1.303 2004/07/02 16:29:55 niklas Exp $	*/
 /*	$NetBSD: machdep.c,v 1.214 1996/11/10 03:16:17 thorpej Exp $	*/
 
 /*-
@@ -2268,8 +2268,8 @@ sendsig(catcher, sig, mask, code, type, val)
 	} else
 #endif
 	{
-		__asm("movw %%gs,%w0" : "=r" (frame.sf_sc.sc_gs));
-		__asm("movw %%fs,%w0" : "=r" (frame.sf_sc.sc_fs));
+		frame.sf_sc.sc_fs = tf->tf_fs;
+		frame.sf_sc.sc_gs = tf->tf_gs;
 		frame.sf_sc.sc_es = tf->tf_es;
 		frame.sf_sc.sc_ds = tf->tf_ds;
 		frame.sf_sc.sc_eflags = tf->tf_eflags;
@@ -2308,8 +2308,8 @@ sendsig(catcher, sig, mask, code, type, val)
 	/*
 	 * Build context to run handler in.
 	 */
-	__asm("movw %w0,%%gs" : : "r" (GSEL(GUDATA_SEL, SEL_UPL)));
-	__asm("movw %w0,%%fs" : : "r" (GSEL(GUDATA_SEL, SEL_UPL)));
+	tf->tf_fs = GSEL(GUDATA_SEL, SEL_UPL);
+	tf->tf_gs = GSEL(GUDATA_SEL, SEL_UPL);
 	tf->tf_es = GSEL(GUDATA_SEL, SEL_UPL);
 	tf->tf_ds = GSEL(GUDATA_SEL, SEL_UPL);
 	tf->tf_eip = p->p_sigcode;
@@ -2376,7 +2376,8 @@ sys_sigreturn(p, v, retval)
 		    !USERMODE(context.sc_cs, context.sc_eflags))
 			return (EINVAL);
 
-		/* %fs and %gs were restored by the trampoline. */
+		tf->tf_fs = context.sc_fs;
+		tf->tf_gs = context.sc_gs;
 		tf->tf_es = context.sc_es;
 		tf->tf_ds = context.sc_ds;
 		tf->tf_eflags = context.sc_eflags;
@@ -2718,8 +2719,8 @@ setregs(p, pack, stack, retval)
 	} else
 		pcb->pcb_savefpu.sv_87.sv_env.en_cw = __OpenBSD_NPXCW__;
 
-	__asm("movw %w0,%%gs" : : "r" (LSEL(LUDATA_SEL, SEL_UPL)));
-	__asm("movw %w0,%%fs" : : "r" (LSEL(LUDATA_SEL, SEL_UPL)));
+	tf->tf_fs = LSEL(LUDATA_SEL, SEL_UPL);
+	tf->tf_gs = LSEL(LUDATA_SEL, SEL_UPL);
 	tf->tf_es = LSEL(LUDATA_SEL, SEL_UPL);
 	tf->tf_ds = LSEL(LUDATA_SEL, SEL_UPL);
 	tf->tf_ebp = 0;
@@ -2869,7 +2870,7 @@ init386(paddr_t first_avail)
 	bios_memmap_t *im;
 
 	proc0.p_addr = proc0paddr;
-	curpcb = &proc0.p_addr->u_pcb;
+	cpu_info_primary.ci_curpcb = &proc0.p_addr->u_pcb;
 
 	/*
 	 * Initialize the I/O port and I/O mem extent maps.
diff --git a/sys/arch/i386/i386/pmap.c b/sys/arch/i386/i386/pmap.c
index ea8bc0b9efe..e4fdf112d48 100644
--- a/sys/arch/i386/i386/pmap.c
+++ b/sys/arch/i386/i386/pmap.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: pmap.c,v 1.77 2004/06/23 17:42:46 niklas Exp $	*/
+/*	$OpenBSD: pmap.c,v 1.78 2004/07/02 16:29:55 niklas Exp $	*/
 /*	$NetBSD: pmap.c,v 1.91 2000/06/02 17:46:37 thorpej Exp $	*/
 
 /*
@@ -935,8 +935,6 @@ pmap_bootstrap(kva_start)
 	 * operation of the system.
 	 */
 
-	curpcb->pcb_pmap = kpm;	/* proc0's pcb */
-
 	/*
 	 * enable global TLB entries if they are supported
 	 */
diff --git a/sys/arch/i386/i386/process_machdep.c b/sys/arch/i386/i386/process_machdep.c
index fbf8c250220..32476fdec43 100644
--- a/sys/arch/i386/i386/process_machdep.c
+++ b/sys/arch/i386/i386/process_machdep.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: process_machdep.c,v 1.16 2004/06/13 21:49:15 niklas Exp $	*/
+/*	$OpenBSD: process_machdep.c,v 1.17 2004/07/02 16:29:55 niklas Exp $	*/
 /*	$NetBSD: process_machdep.c,v 1.22 1996/05/03 19:42:25 christos Exp $	*/
 
 /*
@@ -168,7 +168,6 @@ process_read_regs(p, regs)
 	struct reg *regs;
 {
 	struct trapframe *tf = process_frame(p);
-	struct pcb *pcb = &p->p_addr->u_pcb;
 
 #ifdef VM86
 	if (tf->tf_eflags & PSL_VM) {
@@ -180,8 +179,8 @@ process_read_regs(p, regs)
 	} else
 #endif
 	{
-		regs->r_gs = pcb->pcb_gs & 0xffff;
-		regs->r_fs = pcb->pcb_fs & 0xffff;
+		regs->r_gs = tf->tf_gs & 0xffff;
+		regs->r_fs = tf->tf_fs & 0xffff;
 		regs->r_es = tf->tf_es & 0xffff;
 		regs->r_ds = tf->tf_ds & 0xffff;
 		regs->r_eflags = tf->tf_eflags;
@@ -236,7 +235,6 @@ process_write_regs(p, regs)
 	struct reg *regs;
 {
 	struct trapframe *tf = process_frame(p);
-	struct pcb *pcb = &p->p_addr->u_pcb;
 
 #ifdef VM86
 	if (tf->tf_eflags & PSL_VM) {
@@ -248,23 +246,6 @@ process_write_regs(p, regs)
 	} else
 #endif
 	{
-#if 0
-		extern int gdt_size;
-
-#define	verr_ldt(slot)	(slot < pcb->pcb_ldt_len && \
-			 (pcb->pcb_ldt[slot].sd.sd_type & SDT_MEMRO) != 0 && \
-			 pcb->pcb_ldt[slot].sd.sd_dpl == SEL_UPL && \
-			 pcb->pcb_ldt[slot].sd.sd_p == 1)
-#define	verr_gdt(slot)	(slot < gdt_size && \
-			 (gdt[slot].sd.sd_type & SDT_MEMRO) != 0 && \
-			 gdt[slot].sd.sd_dpl == SEL_UPL && \
-			 gdt[slot].sd.sd_p == 1)
-#define	verr(sel)	(ISLDT(sel) ? verr_ldt(IDXSEL(sel)) : \
-				      verr_gdt(IDXSEL(sel)))
-#define	valid_sel(sel)	(ISPL(sel) == SEL_UPL && verr(sel))
-#define	null_sel(sel)	(!ISLDT(sel) && IDXSEL(sel) == 0)
-#endif
-
 		/*
 		 * Check for security violations.
 		 */
@@ -272,17 +253,8 @@ process_write_regs(p, regs)
 		    !USERMODE(regs->r_cs, regs->r_eflags))
 			return (EINVAL);
 
-		/* XXX Is this safe to remove. */
-#if 0
-		if ((regs->r_gs != pcb->pcb_gs && \
-		     !valid_sel(regs->r_gs) && !null_sel(regs->r_gs)) ||
-		    (regs->r_fs != pcb->pcb_fs && \
-		     !valid_sel(regs->r_fs) && !null_sel(regs->r_fs)))
-			return (EINVAL);
-#endif
-
-		pcb->pcb_gs = regs->r_gs & 0xffff;
-		pcb->pcb_fs = regs->r_fs & 0xffff;
+		tf->tf_gs = regs->r_gs & 0xffff;
+		tf->tf_fs = regs->r_fs & 0xffff;
 		tf->tf_es = regs->r_es & 0xffff;
 		tf->tf_ds = regs->r_ds & 0xffff;
 		tf->tf_eflags = regs->r_eflags;
diff --git a/sys/arch/i386/i386/svr4_machdep.c b/sys/arch/i386/i386/svr4_machdep.c
index b50246f2108..9fe0fe5ba19 100644
--- a/sys/arch/i386/i386/svr4_machdep.c
+++ b/sys/arch/i386/i386/svr4_machdep.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: svr4_machdep.c,v 1.20 2003/05/13 03:49:04 art Exp $	*/
+/*	$OpenBSD: svr4_machdep.c,v 1.21 2004/07/02 16:29:55 niklas Exp $	*/
 /*	$NetBSD: svr4_machdep.c,v 1.24 1996/05/03 19:42:26 christos Exp $	 */
 
 /*
@@ -85,8 +85,8 @@ svr4_getcontext(p, uc, mask, oonstack)
 	} else
 #endif
 	{
-	        __asm("movl %%gs,%k0" : "=r" (r[SVR4_X86_GS]));
-		__asm("movl %%fs,%k0" : "=r" (r[SVR4_X86_FS]));
+		r[SVR4_X86_FS] = tf->tf_fs;
+		r[SVR4_X86_GS] = tf->tf_gs;
 		r[SVR4_X86_ES] = tf->tf_es;
 		r[SVR4_X86_DS] = tf->tf_ds;
 		r[SVR4_X86_EFL] = tf->tf_eflags;
@@ -179,7 +179,8 @@ svr4_setcontext(p, uc)
 		    !USERMODE(r[SVR4_X86_CS], r[SVR4_X86_EFL]))
 			return (EINVAL);
 
-		/* %fs and %gs were restored by the trampoline. */
+		tf->tf_fs = r[SVR4_X86_FS];
+		tf->tf_gs = r[SVR4_X86_GS];
 		tf->tf_es = r[SVR4_X86_ES];
 		tf->tf_ds = r[SVR4_X86_DS];
 		tf->tf_eflags = r[SVR4_X86_EFL];
diff --git a/sys/arch/i386/i386/trap.c b/sys/arch/i386/i386/trap.c
index 223c6bf3544..5a5541184b6 100644
--- a/sys/arch/i386/i386/trap.c
+++ b/sys/arch/i386/i386/trap.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: trap.c,v 1.63 2004/06/13 21:49:15 niklas Exp $	*/
+/*	$OpenBSD: trap.c,v 1.64 2004/07/02 16:29:55 niklas Exp $	*/
 /*	$NetBSD: trap.c,v 1.95 1996/05/05 06:50:02 mycroft Exp $	*/
 
 /*-
@@ -180,7 +180,8 @@ trap(frame)
 	int type = frame.tf_trapno;
 	u_quad_t sticks;
 	struct pcb *pcb = NULL;
-	extern char resume_iret[], resume_pop_ds[], resume_pop_es[];
+	extern char resume_iret[], resume_pop_ds[], resume_pop_es[],
+	    resume_pop_fs[], resume_pop_gs[];
 	struct trapframe *vframe;
 	int resume;
 	vm_prot_t vftype, ftype;
@@ -298,17 +299,34 @@ trap(frame)
 		 */
 		switch (*(u_char *)frame.tf_eip) {
 		case 0xcf:	/* iret */
-			vframe = (void *)((int)&frame.tf_esp - 44);
+			vframe = (void *)((int)&frame.tf_esp -
+			    offsetof(struct trapframe, tf_eip));
 			resume = (int)resume_iret;
 			break;
 		case 0x1f:	/* popl %ds */
-			vframe = (void *)((int)&frame.tf_esp - 4);
+			vframe = (void *)((int)&frame.tf_esp -
+			    offsetof(struct trapframe, tf_ds));
 			resume = (int)resume_pop_ds;
 			break;
 		case 0x07:	/* popl %es */
-			vframe = (void *)((int)&frame.tf_esp - 0);
+			vframe = (void *)((int)&frame.tf_esp -
+			    offsetof(struct trapframe, tf_es));
 			resume = (int)resume_pop_es;
 			break;
+		case 0x0f:	/* 0x0f prefix */
+			switch (*(u_char *)(frame.tf_eip+1)) {
+			case 0xa1:		/* popl %fs */
+				vframe = (void *)((int)&frame.tf_esp - 
+				    offsetof(struct trapframe, tf_fs));
+				resume = (int)resume_pop_fs;
+				break;
+			case 0xa9:		/* popl %gs */
+				vframe = (void *)((int)&frame.tf_esp -
+				    offsetof(struct trapframe, tf_gs));
+				resume = (int)resume_pop_gs;
+				break;
+			}
+                        break;
 		default:
 			goto we_re_toast;
 		}
diff --git a/sys/arch/i386/include/db_machdep.h b/sys/arch/i386/include/db_machdep.h
index 4d4be44f9a7..d39c95fd135 100644
--- a/sys/arch/i386/include/db_machdep.h
+++ b/sys/arch/i386/include/db_machdep.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: db_machdep.h,v 1.11 2004/06/21 22:41:11 andreas Exp $	*/
+/*	$OpenBSD: db_machdep.h,v 1.12 2004/07/02 16:29:55 niklas Exp $	*/
 /*	$NetBSD: db_machdep.h,v 1.9 1996/05/03 19:23:59 christos Exp $	*/
 
 /* 
@@ -106,7 +106,7 @@ boolean_t	db_phys_eq(task_t, vaddr_t, task_t, vaddr_t);
  * Constants for KGDB.
  */
 typedef	long		kgdb_reg_t;
-#define	KGDB_NUMREGS	14
+#define	KGDB_NUMREGS	16
 #define	KGDB_BUFLEN	512
 
 #if 0
diff --git a/sys/arch/i386/include/frame.h b/sys/arch/i386/include/frame.h
index 5c408bc0a27..cbe9a1a805d 100644
--- a/sys/arch/i386/include/frame.h
+++ b/sys/arch/i386/include/frame.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: frame.h,v 1.5 2003/06/02 23:27:47 millert Exp $	*/
+/*	$OpenBSD: frame.h,v 1.6 2004/07/02 16:29:55 niklas Exp $	*/
 /*	$NetBSD: frame.h,v 1.12 1995/10/11 04:20:08 mycroft Exp $	*/
 
 /*-
@@ -46,6 +46,8 @@
  * Exception/Trap Stack Frame
  */
 struct trapframe {
+	int	tf_fs;
+	int	tf_gs;
 	int	tf_es;
 	int	tf_ds;
 	int	tf_edi;
@@ -76,6 +78,8 @@ struct trapframe {
  */
 struct intrframe {
 	int	if_ppl;
+	int	if_fs;
+	int	if_gs;
 	int	if_es;
 	int	if_ds;
 	int	if_edi;
diff --git a/sys/arch/i386/include/pcb.h b/sys/arch/i386/include/pcb.h
index 641f8874f17..0788135e06d 100644
--- a/sys/arch/i386/include/pcb.h
+++ b/sys/arch/i386/include/pcb.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: pcb.h,v 1.12 2004/06/13 21:49:16 niklas Exp $	*/
+/*	$OpenBSD: pcb.h,v 1.13 2004/07/02 16:29:55 niklas Exp $	*/
 /*	$NetBSD: pcb.h,v 1.21 1996/01/08 13:51:42 mycroft Exp $	*/
 
 /*-
@@ -58,8 +58,6 @@ struct pcb {
 #define	pcb_esp	pcb_tss.tss_esp
 #define	pcb_ebp	pcb_tss.tss_ebp
 #define	pcb_cs	pcb_tss.tss_cs
-#define	pcb_fs	pcb_tss.tss_fs
-#define	pcb_gs	pcb_tss.tss_gs
 #define	pcb_ldt_sel	pcb_tss.tss_ldt
 	int	pcb_tss_sel;
 	union	descriptor *pcb_ldt;	/* per process (user) LDT */