Date: Mon, 18 Dec 1995 07:58:18 +0100 (MET) From: aagero@aage.aage.priv.no To: FreeBSD-gnats-submit@freebsd.org Subject: kern/901: busy pages get free'd by vm_page_free Message-ID: <199512180658.HAA12860@birk04.studby.uio.no> Resent-Message-ID: <199512180700.XAA07630@freefall.freebsd.org>
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>Number: 901 >Category: kern >Synopsis: vm_page_free frees wrong pages in vfs_bio.c >Confidential: no >Severity: serious >Priority: medium >Responsible: freebsd-bugs >State: open >Class: sw-bug >Submitter-Id: current-users >Arrival-Date: Sun Dec 17 23:00:01 PST 1995 >Last-Modified: >Originator: Åge Røbekk >Organization: >Release: FreeBSD 2.2-CURRENT i386 >Environment: FreeBSD-CURRENT 14. dec. sources. >Description: vm_page_free() in vfs_bio.c has an incorrent index of the free(?) pages. When vm_hold_free_pages() calls vm_page_free() it points to the wrong page due to the index being a signed datatype. >How-To-Repeat: Do a lot of activity, in order to get the paging moving. Usually ls -lR / has been sufficient. >Fix: Apply the included patch. --- kern/vfs_bio.c Sun Dec 17 02:51:17 1995 +++ kern/vfs_bio.c~ Sun Dec 17 02:51:04 1995 @@ -1634,7 +1634,7 @@ vm_offset_t to = round_page(toa); for (pg = from; pg < to; pg += PAGE_SIZE) { - int index = ((caddr_t) pg - bp->b_data) >> PAGE_SHIFT; + unsigned int index = ((caddr_t) pg - bp->b_data) >> PAGE_SHIFT; p = bp->b_pages[index]; bp->b_pages[index] = 0; pmap_kremove(pg); >Audit-Trail: >Unformatted:
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