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Date: Fri, 17 Nov 2000 11:23:33 +0000
From: Francois romieu <romieu@ensta.fr>
To: Dan Aloni <karrde@callisto.yi.org>
Cc: linux-kernel <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH (2.4)] atomic use count for proc_dir_entry
Message-ID: <20001117112333.D839@nic.fr>
Reply-To: Francois romieu <romieu@ensta.fr>
In-Reply-To: <Pine.LNX.4.21.0011162320230.17038-100000@callisto.yi.org> <Pine.LNX.4.21.0011171015270.19287-100000@callisto.yi.org>
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CPU A: assume de->count = 1 (in de_put)
fs/proc/inode.c::44 if (!--de->count) {
de->count = 0

CPU B: (in remove_proc_entry)
fs/proc/generic.c::577         if (!de->count)
fs/proc/generic.c::578             free_proc_entry(de);

CPU A: (in de_put)
fs/proc/inode.c::45 if (de->deleted) { <-- dereferencing kfreed pointer

What does protect us from the preceding if lock_kernel is thrown ?

-- 
Ueimor
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