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From: "David S. Miller" <davem@redhat.com>
To: weigand@immd1.informatik.uni-erlangen.de
Cc: levon@movementarian.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] [8/7] oprofile - dcookies need to use u32
Date: Tue, 15 Oct 2002 19:00:19 -0700 (PDT)	[thread overview]
Message-ID: <20021015.190019.41374479.davem@redhat.com> (raw)
In-Reply-To: <200210160156.DAA25005@faui11.informatik.uni-erlangen.de>

   From: Ulrich Weigand <weigand@immd1.informatik.uni-erlangen.de>
   Date: Wed, 16 Oct 2002 03:56:10 +0200 (MET DST)

   +               return (u32)dentry;
   
   Um, isn't this supposed to uniquely identify the dentry?
   On a platform with 64-bit pointers there's now the theoretical
   possibility of different dentries getting the same cookie ...

That's true.

We dealt with this (trying to use a kernel pointer as a cache held by
userspace) in tcp_diag by making the actual object opaque.  It was
actually two u32's, and that way it worked independant of kernel
vs. user word size.


  reply	other threads:[~2002-10-16  2:02 UTC|newest]

Thread overview: 21+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2002-10-16  1:56 [PATCH] [8/7] oprofile - dcookies need to use u32 Ulrich Weigand
2002-10-16  2:00 ` David S. Miller [this message]
2002-10-16 16:40   ` John Levon
2002-10-16 18:29     ` Jeff Garzik
2002-10-16 21:38     ` David S. Miller
2002-10-17  0:57       ` John Levon
2002-10-17  0:55         ` David S. Miller
2002-10-17  1:16           ` John Levon
2002-10-17  1:12             ` David S. Miller
2002-10-19  0:26               ` John Levon
2002-10-19  0:23                 ` David S. Miller
2002-10-19  0:34                   ` John Levon
2002-10-19  0:31                     ` David S. Miller
2002-10-19  0:40                       ` John Levon
2002-10-19  0:35                         ` David S. Miller
2002-11-01  4:33                       ` John Levon
2002-11-01 10:27                         ` David S. Miller
  -- strict thread matches above, loose matches on Subject: below --
2002-10-15 22:32 [PATCH] [2/7] oprofile - dcookies John Levon
2002-10-15 23:37 ` David S. Miller
2002-10-16  0:06   ` [PATCH] [8/7] oprofile - dcookies need to use u32 John Levon
2002-10-16  0:01     ` David S. Miller
2002-10-16  1:33     ` Linus Torvalds
2002-10-16  1:35       ` John Levon

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