Date: Sat, 17 Oct 2009 23:42:40 -0700 From: Julian Elischer <julian@elischer.org> To: Harsha <inpcb.harsha@gmail.com> Cc: freebsd-current@freebsd.org, "Robert N. M. Watson" <rwatson@freebsd.org>, net@freebsd.org Subject: Re: Page fault in IFNET_WLOCK_ASSERT [if.c and pccbb.c] Message-ID: <4ADAB8E0.3090502@elischer.org> In-Reply-To: <e1b1c5880910172328s6bc0c53ctc782b9993ffbdb00@mail.gmail.com> References: <e1b1c5880910111226o65e0d1a9va975f4cd837271bb@mail.gmail.com> <alpine.BSF.2.00.0910112126050.48605@fledge.watson.org> <e1b1c5880910112138x1b46ff0eo39c10691a978c164@mail.gmail.com> <FE5F0845-B909-4B9B-A999-DAA7D8F4E56D@freebsd.org> <e1b1c5880910172328s6bc0c53ctc782b9993ffbdb00@mail.gmail.com>
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Harsha wrote: > Hi Robert, > > Apologies for not getting earlier. > > On Mon, Oct 12, 2009 at 6:46 AM, Robert N. M. Watson > <rwatson@freebsd.org> wrote: >> Looks like a NULL pointer dereference, so perhaps a more traditional bug -- >> could you convert ifindex_alloc_locked+0x71 to a line of code? You can do >> this using kgdb on the kernel symbols file, perhaps "l >> *ifindex_alloc_locked+0x71". > It is the for loop in ifindex_alloc_locked() function- > for (idx = 1; idx <= V_if_index; idx++) > > idx is a local variable, so I figured it is V_if_index is what is > causing the page fault. It does look like a NULL pointer reference - I > see that V_if_index comes from that vnet instance's value and uses > the macro VNET_VNET_PTR() down the chain. Since the call chain is > coming from a new thread cbb_event_thread, I believe that this > thread's vnet context needs to be set using CURVNET_SET(). but only if you have options VIMAGE defined. if not then CURVNET_SET() is a NOP > > I'll try this tomorrow, but if think I'm not on the right track or > want me to try something else please let me know. > > Many thanks, > Harsha > _______________________________________________ > freebsd-net@freebsd.org mailing list > http://lists.freebsd.org/mailman/listinfo/freebsd-net > To unsubscribe, send any mail to "freebsd-net-unsubscribe@freebsd.org"
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