CVS commit: src/sys

[Maxime Villard]

Module Name:    src
Committed By:   maxv
Date:           Fri Nov  8 12:36:11 UTC 2019

Modified Files:
        src/sys/arch/amd64/include: csan.h
        src/sys/kern: subr_csan.c

Log Message:
Exclude the PTE space from KCSAN, since there the same VA can point to
different PAs.


To generate a diff of this commit:
cvs rdiff -u -r1.2 -r1.3 src/sys/arch/amd64/include/csan.h
cvs rdiff -u -r1.2 -r1.3 src/sys/kern/subr_csan.c

Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.


Modified files:

Index: src/sys/arch/amd64/include/csan.h
diff -u src/sys/arch/amd64/include/csan.h:1.2 src/sys/arch/amd64/include/csan.h:1.3
--- src/sys/arch/amd64/include/csan.h:1.2	Wed Nov  6 06:57:22 2019
+++ src/sys/arch/amd64/include/csan.h	Fri Nov  8 12:36:11 2019
@@ -1,4 +1,4 @@
-/*	$NetBSD: csan.h,v 1.2 2019/11/06 06:57:22 maxv Exp $	*/
+/*	$NetBSD: csan.h,v 1.3 2019/11/08 12:36:11 maxv Exp $	*/
 
 /*
  * Copyright (c) 2019 The NetBSD Foundation, Inc.
@@ -30,9 +30,18 @@
  */
 
 #include <sys/ksyms.h>
+#include <uvm/uvm.h>
+#include <amd64/pmap.h>
 #include <x86/cpufunc.h>
 
 static inline bool
+kcsan_md_unsupported(vaddr_t addr)
+{
+	return (addr >= (vaddr_t)PTE_BASE &&
+	    addr < ((vaddr_t)PTE_BASE + NBPD_L4));
+}
+
+static inline bool
 kcsan_md_is_avail(void)
 {
 	return true;

Index: src/sys/kern/subr_csan.c
diff -u src/sys/kern/subr_csan.c:1.2 src/sys/kern/subr_csan.c:1.3
--- src/sys/kern/subr_csan.c:1.2	Wed Nov  6 06:57:22 2019
+++ src/sys/kern/subr_csan.c	Fri Nov  8 12:36:10 2019
@@ -1,4 +1,4 @@
-/*	$NetBSD: subr_csan.c,v 1.2 2019/11/06 06:57:22 maxv Exp $	*/
+/*	$NetBSD: subr_csan.c,v 1.3 2019/11/08 12:36:10 maxv Exp $	*/
 
 /*
  * Copyright (c) 2019 The NetBSD Foundation, Inc.
@@ -30,7 +30,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: subr_csan.c,v 1.2 2019/11/06 06:57:22 maxv Exp $");
+__KERNEL_RCSID(0, "$NetBSD: subr_csan.c,v 1.3 2019/11/08 12:36:10 maxv Exp $");
 
 #include "opt_kcsan.h"
 
@@ -136,6 +136,8 @@ kcsan_access(uintptr_t addr, size_t size
 
 	if (__predict_false(!kcsan_enabled))
 		return;
+	if (__predict_false(kcsan_md_unsupported((vaddr_t)addr)))
+		return;
 
 	new.addr = addr;
 	new.size = size;