Module Name: src
Committed By: ad
Date: Sun Dec 22 15:15:20 UTC 2019
Modified Files:
src/sys/arch/x86/x86: pmap.c
Log Message:
pmap_get_ptp(): the uvm_pagefree() call in the failure case can block too.
Pacify the assertion in pmap_unmap_ptes().
XXX Revisit and solve this chicken-and-egg problem in a more elegant way.
Reported-by: syzbot+24967905b8d173445...@syzkaller.appspotmail.com
To generate a diff of this commit:
cvs rdiff -u -r1.347 -r1.348 src/sys/arch/x86/x86/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/x86/x86/pmap.c
diff -u src/sys/arch/x86/x86/pmap.c:1.347 src/sys/arch/x86/x86/pmap.c:1.348
--- src/sys/arch/x86/x86/pmap.c:1.347 Sat Dec 21 13:00:24 2019
+++ src/sys/arch/x86/x86/pmap.c Sun Dec 22 15:15:20 2019
@@ -1,4 +1,4 @@
-/* $NetBSD: pmap.c,v 1.347 2019/12/21 13:00:24 ad Exp $ */
+/* $NetBSD: pmap.c,v 1.348 2019/12/22 15:15:20 ad Exp $ */
/*
* Copyright (c) 2008, 2010, 2016, 2017, 2019 The NetBSD Foundation, Inc.
@@ -130,7 +130,7 @@
*/
#include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: pmap.c,v 1.347 2019/12/21 13:00:24 ad Exp $");
+__KERNEL_RCSID(0, "$NetBSD: pmap.c,v 1.348 2019/12/22 15:15:20 ad Exp $");
#include "opt_user_ldt.h"
#include "opt_lockdebug.h"
@@ -2120,8 +2120,6 @@ pmap_get_ptp(struct pmap *pmap, vaddr_t
pt[i].new = true;
if (__predict_false(ncsw != lwp_pctr())) {
/* uvm_pagealloc can block. */
- /* XXX silence assertion in pmap_unmap_ptes */
- pmap->pm_ncsw = lwp_pctr();
error = EAGAIN;
goto fail;
}
@@ -2195,9 +2193,10 @@ fail:
if (!pt[i].new) {
continue;
}
- obj = &pmap->pm_obj[i - 2];
uvm_pagefree(pt[i].pg);
}
+ /* XXX silence assertion in pmap_unmap_ptes */
+ pmap->pm_ncsw = lwp_pctr();
return error;
}
