Date: Mon, 21 Jul 2003 12:03:59 -0700 (PDT) From: Matthew Dillon <dillon@apollo.backplane.com> To: Pawel Jakub Dawidek <nick@garage.freebsd.pl> Cc: freebsd-hackers@freebsd.org Subject: Re: VM problem... Message-ID: <200307211903.h6LJ3xrX027536@apollo.backplane.com> References: <20030720235759.GJ437@garage.freebsd.pl> <20030721181805.GA43543@garage.freebsd.pl>
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Hmm. Is the VM object properly sized? Any attempt to fault-in data
beyond a VM object's EOF, regardless of how you set the map_entry
permissions, will seg fault or bus fault.
-Matt
Matthew Dillon
<dillon@backplane.com>
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:On Mon, Jul 21, 2003 at 01:57:59AM +0200, Pawel Jakub Dawidek wrote:
:+> So as you can see I'm listing every entry that isn't writable.
:+> This function is called when process is killed by kernel with SIGBUS.
:+> It shows me that only this region isn't writable:
:+>=20
:+> ENTRY:<PID>: 0-0xbfc00000 (0:0)
:
:Of course it isn't it. I've changed all map entries protection to
:VM_PROT_ALL and now on SIGBUS (in trapsignal()) every listed entry
:got protection =3D VM_PROT_ALL and max_protection =3D VM_PROT_ALL.
:So what the hell is going on here?:S
:
:I'm not a VM expert so please help me to track this down. I'm trying
:real hard to made this by myself for a week now.
:
:Is there posibility that there is some map entry that isn't on process
:p->p_vmspace->vm_map? Maybe some shared entry not connected with his
:map, but which should be accessable for this process?
:
:If trap is generated, because of illegal access nothing is changed
:with map entries before trapsignal() is called?
:
:I'm really confused, so if someone could find few minutes, hour or short
:day:) to help me track this down, I'll be really grateful.
:
:--=20
:Pawel Jakub Dawidek pawel@dawidek.net
:UNIX Systems Programmer/Administrator http://garage.freebsd.pl
:Am I Evil? Yes, I Am! http://cerber.sourceforge.net
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