Enable vmspace sharing on SMP. Major changes are,

- %fs register is added to trapframe and saved/restored upon kernel entry/exit.
- Per-cpu pages are no longer mapped at the same virtual address.
- Each cpu now has a separate gdt selector table. A new segment selector
  is added to point to per-cpu pages, per-cpu global variables are now
  accessed through this new selector (%fs). The selectors in gdt table are
  rearranged for cache line optimization.
- fask_vfork is now on as default for both UP and SMP.
- Some aio code cleanup.

Reviewed by:	Alan Cox	<alc@cs.rice.edu>
		John Dyson	<dyson@iquest.net>
		Julian Elischer	<julian@whistel.com>
		Bruce Evans	<bde@zeta.org.au>
		David Greenman	<dg@root.com>

2 files changed, 13 insertions, 2 deletions

diff --git a/sys/i386/svr4/svr4_locore.s b/sys/i386/svr4/svr4_locore.s
index 7903e73..2f9c683 100644
--- a/sys/i386/svr4/svr4_locore.s
+++ b/sys/i386/svr4/svr4_locore.s
@@ -13,11 +13,11 @@ NON_GPROF_ENTRY(svr4_sigcode)
 	jnz	1f
 #endif
 #endif
-	movl	SVR4_UC_FS(%eax),%ecx
 	movl	SVR4_UC_GS(%eax),%edx
-	movl	%cx,%fs
 	movl	%dx,%gs
 #if defined(__NetBSD__)	
+	movl	SVR4_UC_FS(%eax),%ecx
+	movl	%cx,%fs
 1:	pushl	%eax
 	pushl	$1			# setcontext(p) == syscontext(1, p) 
 	pushl	%eax			# junk to fake return address
diff --git a/sys/i386/svr4/svr4_machdep.c b/sys/i386/svr4/svr4_machdep.c
index a94f45e..5e77fd1 100644
--- a/sys/i386/svr4/svr4_machdep.c
+++ b/sys/i386/svr4/svr4_machdep.c
@@ -127,8 +127,13 @@ svr4_getcontext(p, uc, mask, oonstack)
 	} else
 #endif
 	{
+#if defined(__NetBSD__)
 	        __asm("movl %%gs,%w0" : "=r" (r[SVR4_X86_GS]));
 		__asm("movl %%fs,%w0" : "=r" (r[SVR4_X86_FS]));
+#else
+	        r[SVR4_X86_GS] = rgs();
+		r[SVR4_X86_FS] = tf->tf_fs;
+#endif
 		r[SVR4_X86_ES] = tf->tf_es;
 		r[SVR4_X86_DS] = tf->tf_ds;
 		r[SVR4_X86_EFL] = tf->tf_eflags;
@@ -230,7 +235,12 @@ svr4_setcontext(p, uc)
 		    !USERMODE(r[SVR4_X86_CS], r[SVR4_X86_EFL]))
 			return (EINVAL);
 
+#if defined(__NetBSD__)
 		/* %fs and %gs were restored by the trampoline. */
+#else
+		/* %gs was restored by the trampoline. */
+		tf->tf_fs = r[SVR4_X86_FS];
+#endif
 		tf->tf_es = r[SVR4_X86_ES];
 		tf->tf_ds = r[SVR4_X86_DS];
 		tf->tf_eflags = r[SVR4_X86_EFL];
@@ -449,6 +459,7 @@ svr4_sendsig(catcher, sig, mask, code)
 	tf->tf_cs = _ucodesel;
 	tf->tf_ds = _udatasel;
 	tf->tf_es = _udatasel;
+	tf->tf_fs = _udatasel;
 	tf->tf_ss = _udatasel;
 #endif
 }