Date: Sun, 8 May 2005 17:00:40 -0700 (PDT) From: Doug White <dwhite@gumbysoft.com> To: Kris Kennaway <kris@obsecurity.org> Cc: current@FreeBSD.org Subject: Re: ptcwrite panic (with dump) Message-ID: <20050508165054.S77229@carver.gumbysoft.com> In-Reply-To: <20050508233831.GA33797@xor.obsecurity.org> References: <20050508231255.GA28688@xor.obsecurity.org> <20050508163107.A77229@carver.gumbysoft.com> <20050508233831.GA33797@xor.obsecurity.org>
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On Sun, 8 May 2005, Kris Kennaway wrote: > $2 = (struct pgrp *) 0x0 Looks like t_pgrp became NULL between us checking it and us inspecting the list attached to it. Nice. Try moving the sx_slock(&proctree_lock); grab above the tp->t_pgrp NULL check and add a sx_sunlock(&proctree_lock); inside that if() block. I don't know if proctree_lock or the per-tty mutex protects the t_pgrp item in struct tty. In any case we need to pick up some lock to keep it from going away :-) I'll bash up a draft patch for discussion. -- Doug White | FreeBSD: The Power to Serve dwhite@gumbysoft.com | www.FreeBSD.org
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