Module Name: src
Committed By: rin
Date: Thu Sep 2 07:55:56 UTC 2021
Modified Files:
src/sys/arch/sh3/sh3: pmap.c
Log Message:
PR port-sh3/56381
pmap_enter() returns ENOMEM if __pmap_pte_alloc() fails and PMAP_CANFAIL
flag is specified. In this case, remove pv via __pmap_pv_remove() if it is
added to p-v map list via __pmap_pv_enter().
Otherwise, pmap becomes an inconsistent state, which results in an infinite
loop in pmap_page_protect(), as reported in the PR.
Also, KASSERT's are added for sure, in order to detect the infinite loops.
Great thanks to chs@ for finding out this bug!!
To generate a diff of this commit:
cvs rdiff -u -r1.85 -r1.86 src/sys/arch/sh3/sh3/pmap.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/sh3/sh3/pmap.c
diff -u src/sys/arch/sh3/sh3/pmap.c:1.85 src/sys/arch/sh3/sh3/pmap.c:1.86
--- src/sys/arch/sh3/sh3/pmap.c:1.85 Mon Jul 26 21:43:11 2021
+++ src/sys/arch/sh3/sh3/pmap.c Thu Sep 2 07:55:56 2021
@@ -1,4 +1,4 @@
-/* $NetBSD: pmap.c,v 1.85 2021/07/26 21:43:11 andvar Exp $ */
+/* $NetBSD: pmap.c,v 1.86 2021/09/02 07:55:56 rin Exp $ */
/*-
* Copyright (c) 2002 The NetBSD Foundation, Inc.
@@ -30,7 +30,7 @@
*/
#include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: pmap.c,v 1.85 2021/07/26 21:43:11 andvar Exp $");
+__KERNEL_RCSID(0, "$NetBSD: pmap.c,v 1.86 2021/09/02 07:55:56 rin Exp $");
#include <sys/param.h>
#include <sys/systm.h>
@@ -385,9 +385,12 @@ pmap_enter(pmap_t pmap, vaddr_t va, padd
else {
pte = __pmap_pte_alloc(pmap, va);
if (pte == NULL) {
- if (flags & PMAP_CANFAIL)
+ if (flags & PMAP_CANFAIL) {
+ if (pg != NULL)
+ __pmap_pv_remove(pmap, pg, va);
return ENOMEM;
- panic("pmap_enter: cannot allocate pte");
+ }
+ panic("%s: __pmap_pte_alloc failed", __func__);
}
}
@@ -724,8 +727,14 @@ pmap_page_protect(struct vm_page *pg, vm
/* Remove all */
s = splvm();
while ((pv = SLIST_FIRST(&pvh->pvh_head)) != NULL) {
+ pmap = pv->pv_pmap;
va = pv->pv_va;
- pmap_remove(pv->pv_pmap, va, va + PAGE_SIZE);
+#ifdef DIAGNOSTIC
+ pt_entry_t *pte = __pmap_pte_lookup(pmap, va);
+ KASSERT(pte != NULL);
+ KASSERT(*pte != 0);
+#endif
+ pmap_remove(pmap, va, va + PAGE_SIZE);
}
splx(s);
}
