Intel P5 f00f workaround; weingart & who knows who else

6 files changed, 74 insertions, 11 deletions

diff --git a/sys/arch/i386/i386/genassym.cf b/sys/arch/i386/i386/genassym.cf
index c7d96c90eff..c811a9dbf20 100644
--- a/sys/arch/i386/i386/genassym.cf
+++ b/sys/arch/i386/i386/genassym.cf
@@ -1,4 +1,4 @@
-#	$OpenBSD: genassym.cf,v 1.5 1997/10/19 06:34:23 mickey Exp $
+#	$OpenBSD: genassym.cf,v 1.6 1997/12/09 03:36:39 deraadt Exp $
 #
 # Copyright (c) 1982, 1990 The Regents of the University of California.
 # All rights reserved.
@@ -108,6 +108,8 @@ define	PCB_ONFAULT	offsetof(struct pcb, pcb_onfault)
 define	TF_CS		offsetof(struct trapframe, tf_cs)
 define	TF_TRAPNO	offsetof(struct trapframe, tf_trapno)
 define	TF_EFLAGS	offsetof(struct trapframe, tf_eflags)
+define	TF_EIP		offsetof(struct trapframe, tf_eip)
+define	TF_ERR		offsetof(struct trapframe, tf_err)
 
 define	FRAMESIZE	sizeof(struct trapframe)
 
diff --git a/sys/arch/i386/i386/locore.s b/sys/arch/i386/i386/locore.s
index fda7798ef74..192fffb44f6 100644
--- a/sys/arch/i386/i386/locore.s
+++ b/sys/arch/i386/i386/locore.s
@@ -1,4 +1,4 @@
-/*	$OpenBSD: locore.s,v 1.36 1997/10/22 23:37:12 mickey Exp $	*/
+/*	$OpenBSD: locore.s,v 1.37 1997/12/09 03:36:39 deraadt Exp $	*/
 /*	$NetBSD: locore.s,v 1.145 1996/05/03 19:41:19 christos Exp $	*/
 
 /*-
@@ -1931,6 +1931,19 @@ IDTVEC(stk)
 	TRAP(T_STKFLT)
 IDTVEC(prot)
 	TRAP(T_PROTFLT)
+#ifdef I586_CPU
+IDTVEC(f00f_redirect)
+	pushl	$T_PAGEFLT
+	INTRENTRY
+	testb	$PGEX_U,TF_ERR(%esp)
+	jnz	calltrap
+	movl	%cr2,%eax
+	subl	_idt,%eax
+	cmpl	$(6*8),%eax
+	jne	calltrap
+	movb	$T_PRIVINFLT,TF_TRAPNO(%esp)
+	jmp	calltrap
+#endif
 IDTVEC(page)
 	TRAP(T_PAGEFLT)
 IDTVEC(rsvd)
diff --git a/sys/arch/i386/i386/machdep.c b/sys/arch/i386/i386/machdep.c
index 61b5522816f..5494dc3d24c 100644
--- a/sys/arch/i386/i386/machdep.c
+++ b/sys/arch/i386/i386/machdep.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: machdep.c,v 1.66 1997/12/02 05:06:41 mickey Exp $	*/
+/*	$OpenBSD: machdep.c,v 1.67 1997/12/09 03:36:40 deraadt Exp $	*/
 /*	$NetBSD: machdep.c,v 1.202 1996/05/18 15:54:59 christos Exp $	*/
 
 /*-
@@ -489,6 +489,10 @@ identifycpu()
 		calibrate_cyclecounter();
 		printf(" %d MHz", pentium_mhz);
 	}
+	if (!strcmp(cpu_model, "Pentium (GenuineIntel 586-class CPU)")) {
+		fix_f00f();
+		printf("\nCPU: F00F bug workaround installed");
+	}
 #endif
 	printf("\n");
 
@@ -1079,7 +1083,8 @@ setregs(p, pack, stack, retval)
 
 union descriptor gdt[NGDT];
 union descriptor ldt[NLDT];
-struct gate_descriptor idt[NIDT];
+struct gate_descriptor idt_region[NIDT];
+struct gate_descriptor *idt = idt_region;
 
 extern  struct user *proc0paddr;
 
@@ -1139,6 +1144,45 @@ extern	IDTVEC(div),     IDTVEC(dbg),     IDTVEC(nmi),     IDTVEC(bpt),
 	IDTVEC(fpu),     IDTVEC(align),
 	IDTVEC(syscall), IDTVEC(osyscall);
 
+#if defined(I586_CPU)
+extern IDTVEC(f00f_redirect);
+pt_entry_t *pmap_pte __P((pmap_t, vm_offset_t));
+
+int cpu_f00f_bug = 0;
+
+void
+fix_f00f()
+{
+	struct region_descriptor region;
+	vm_offset_t va;
+	pt_entry_t *pte;
+	void *p;
+
+	/* Allocate two new pages */
+	va = kmem_alloc(kernel_map, NBPG*2);
+	p = (void *)(va + NBPG - 7*sizeof(*idt));
+
+	/* Copy over old IDT */
+	bcopy(idt, p, sizeof(idt_region));
+	idt = p;
+
+	/* Fix up paging redirect */
+	setgate(&idt[ 14], &IDTVEC(f00f_redirect), 0, SDT_SYS386TGT,
+		SEL_KPL, GCODE_SEL);
+
+	/* Map first page RO */
+	pte = pmap_pte(pmap_kernel(), va);
+	*pte &= ~PG_RW;
+
+	/* Reload idtr */
+	setregion(&region, idt, sizeof(idt_region) - 1);
+	lidt(&region);
+
+	/* Tell the rest of the world */
+	cpu_f00f_bug = 1;
+}
+#endif
+
 void
 init386(first_avail)
 	vm_offset_t first_avail;
@@ -1214,7 +1258,7 @@ init386(first_avail)
 
 	setregion(&region, gdt, sizeof(gdt) - 1);
 	lgdt(&region);
-	setregion(&region, idt, sizeof(idt) - 1);
+	setregion(&region, idt, sizeof(idt_region) - 1);
 	lidt(&region);
 
 #if NISA > 0
@@ -1414,8 +1458,8 @@ cpu_reset()
 	 * Try to cause a triple fault and watchdog reset by setting the
 	 * IDT to point to nothing.
 	 */
-	bzero((caddr_t)idt, sizeof(idt));
-	setregion(&region, idt, sizeof(idt) - 1);
+	bzero((caddr_t)idt, sizeof(idt_region));
+	setregion(&region, idt, sizeof(idt_region) - 1);
 	lidt(&region);
 	__asm __volatile("divl %0,%1" : : "q" (0), "a" (0));
 
diff --git a/sys/arch/i386/include/cpu.h b/sys/arch/i386/include/cpu.h
index ed1b2880f76..15506252a04 100644
--- a/sys/arch/i386/include/cpu.h
+++ b/sys/arch/i386/include/cpu.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: cpu.h,v 1.17 1997/10/25 21:47:27 mickey Exp $	*/
+/*	$OpenBSD: cpu.h,v 1.18 1997/12/09 03:36:41 deraadt Exp $	*/
 /*	$NetBSD: cpu.h,v 1.35 1996/05/05 19:29:26 christos Exp $	*/
 
 /*-
@@ -140,6 +140,10 @@ extern int cpu_class;
 extern struct cpu_nameclass i386_cpus[];
 #ifdef I586_CPU
 extern int pentium_mhz;
+
+/* F00F bug fix stuff for pentium cpu */
+extern int cpu_f00f_bug;
+void fix_f00f __P((void));
 #endif
 
 /* autoconf.c */
diff --git a/sys/arch/i386/include/segments.h b/sys/arch/i386/include/segments.h
index 4aa542dc009..f99604bb380 100644
--- a/sys/arch/i386/include/segments.h
+++ b/sys/arch/i386/include/segments.h
@@ -128,7 +128,8 @@ struct region_descriptor {
 
 #ifdef _KERNEL
 extern union descriptor gdt[], ldt[];
-extern struct gate_descriptor idt[];
+extern struct gate_descriptor idt_region[];
+extern struct gate_descriptor *idt;
 
 void setgate __P((struct gate_descriptor *, void *, int, int, int, int));
 void setregion __P((struct region_descriptor *, void *, size_t));
diff --git a/sys/arch/i386/isa/isa_machdep.c b/sys/arch/i386/isa/isa_machdep.c
index 73cb52256b7..362f0262f71 100644
--- a/sys/arch/i386/isa/isa_machdep.c
+++ b/sys/arch/i386/isa/isa_machdep.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: isa_machdep.c,v 1.22 1997/09/24 22:28:16 niklas Exp $	*/
+/*	$OpenBSD: isa_machdep.c,v 1.23 1997/12/09 03:36:42 deraadt Exp $	*/
 /*	$NetBSD: isa_machdep.c,v 1.14 1996/05/12 23:06:18 mycroft Exp $	*/
 
 /*-
@@ -62,7 +62,6 @@
 /* default interrupt vector table entries */
 typedef (*vector) __P((void));
 extern vector IDTVEC(intr)[], IDTVEC(fast)[];
-extern struct gate_descriptor idt[];
 void isa_strayintr __P((int));
 void intr_calculatemasks __P((void));
 int fakeintr __P((void *));