Module Name: src
Committed By: maxv
Date: Sat May 2 16:25:47 UTC 2020
Modified Files:
src/sys/arch/x86/x86: patch.c
Log Message:
Remove the D bit as part of the hotpatch cleanup procedure.
To generate a diff of this commit:
cvs rdiff -u -r1.47 -r1.48 src/sys/arch/x86/x86/patch.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/x86/x86/patch.c
diff -u src/sys/arch/x86/x86/patch.c:1.47 src/sys/arch/x86/x86/patch.c:1.48
--- src/sys/arch/x86/x86/patch.c:1.47 Sat May 2 11:37:17 2020
+++ src/sys/arch/x86/x86/patch.c Sat May 2 16:25:47 2020
@@ -1,4 +1,4 @@
-/* $NetBSD: patch.c,v 1.47 2020/05/02 11:37:17 maxv Exp $ */
+/* $NetBSD: patch.c,v 1.48 2020/05/02 16:25:47 maxv Exp $ */
/*-
* Copyright (c) 2007, 2008, 2009 The NetBSD Foundation, Inc.
@@ -34,7 +34,7 @@
*/
#include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: patch.c,v 1.47 2020/05/02 11:37:17 maxv Exp $");
+__KERNEL_RCSID(0, "$NetBSD: patch.c,v 1.48 2020/05/02 16:25:47 maxv Exp $");
#include "opt_lockdebug.h"
#ifdef i386
@@ -49,6 +49,9 @@ __KERNEL_RCSID(0, "$NetBSD: patch.c,v 1.
#include <machine/specialreg.h>
#include <machine/frameasm.h>
+#include <uvm/uvm.h>
+#include <machine/pmap.h>
+
#include <x86/cpuvar.h>
#include <x86/cputypes.h>
@@ -256,6 +259,45 @@ x86_hotpatch_apply(uint8_t name, uint8_t
return 0;
}
+#ifdef __x86_64__
+/*
+ * The CPU added the D bit on the text pages while we were writing to them.
+ * Remove that bit. Kinda annoying, but we can't avoid it.
+ */
+static void
+remove_d_bit(void)
+{
+ extern struct bootspace bootspace;
+ pt_entry_t pte;
+ vaddr_t va;
+ size_t i, n;
+
+ for (i = 0; i < BTSPACE_NSEGS; i++) {
+ if (bootspace.segs[i].type != BTSEG_TEXT)
+ continue;
+ va = bootspace.segs[i].va;
+ n = 0;
+ while (n < bootspace.segs[i].sz) {
+ if (L2_BASE[pl2_i(va)] & PTE_PS) {
+ pte = L2_BASE[pl2_i(va)] & ~PTE_D;
+ pmap_pte_set(&L2_BASE[pl2_i(va)], pte);
+ n += NBPD_L2;
+ va += NBPD_L2;
+ } else {
+ pte = L1_BASE[pl1_i(va)] & ~PTE_D;
+ pmap_pte_set(&L1_BASE[pl1_i(va)], pte);
+ n += NBPD_L1;
+ va += NBPD_L1;
+ }
+ }
+ }
+
+ tlbflushg();
+}
+#else
+#define remove_d_bit() __nothing
+#endif
+
/*
* Interrupts disabled here. Called from ASM only, prototype not public.
*/
@@ -266,6 +308,8 @@ x86_hotpatch_cleanup(int retval)
if (retval != 0) {
panic("x86_hotpatch_apply failed");
}
+
+ remove_d_bit();
}
/* -------------------------------------------------------------------------- */
