Re: [PATCH] locking bug in fib_semantics.c

2006-08-24 Thread Stephen Hemminger
Jarek Poplawski wrote: On 23-08-2006 20:31, Stephen Hemminger wrote: On Tue, 22 Aug 2006 12:35:56 +0200 Jarek Poplawski <[EMAIL PROTECTED]> wrote: ... I've found it at last but on that occasion I've got some doubt according to rcu_read_lock and rcu_call treatment: isn't it "illegal to block wh

Re: [PATCH] locking bug in fib_semantics.c

2006-08-24 Thread Jarek Poplawski
On 23-08-2006 20:31, Stephen Hemminger wrote: On Tue, 22 Aug 2006 12:35:56 +0200 Jarek Poplawski <[EMAIL PROTECTED]> wrote: ... I've found it at last but on that occasion I've got some doubt according to rcu_read_lock and rcu_call treatment: isn't it "illegal to block while in an RCU read-side

Re: [PATCH] locking bug in fib_semantics.c

2006-08-23 Thread Stephen Hemminger
On Tue, 22 Aug 2006 12:35:56 +0200 Jarek Poplawski <[EMAIL PROTECTED]> wrote: > On Mon, Aug 21, 2006 at 01:02:01PM +0200, Jarek Poplawski wrote: > > On 21-08-2006 10:17, David Miller wrote: > > > From: Jarek Poplawski <[EMAIL PROTECTED]> > > > Date: Mon, 21 Aug 2006 10:16:43 +0200 > > ... > > > I

Re: [PATCH] locking bug in fib_semantics.c

2006-08-22 Thread Jarek Poplawski
On Tue, Aug 22, 2006 at 12:35:56PM +0200, Jarek Poplawski wrote: ... > Hello, > I've found it at last but on that occasion I've got some > doubt according to rcu_read_lock and rcu_call treatment: ... Actually there is one more doubt (bug really, but not very probable): proc file reading is withou

Re: [PATCH] locking bug in fib_semantics.c

2006-08-22 Thread Jarek Poplawski
On Mon, Aug 21, 2006 at 01:02:01PM +0200, Jarek Poplawski wrote: > On 21-08-2006 10:17, David Miller wrote: > > From: Jarek Poplawski <[EMAIL PROTECTED]> > > Date: Mon, 21 Aug 2006 10:16:43 +0200 > ... > > I was skeptical of this case too, until I checked how > > fib_release_info() was called. > >

Re: [PATCH] locking bug in fib_semantics.c

2006-08-21 Thread Jarek Poplawski
On 21-08-2006 10:17, David Miller wrote: > From: Jarek Poplawski <[EMAIL PROTECTED]> > Date: Mon, 21 Aug 2006 10:16:43 +0200 ... >> But I hope the real reason for this patch isn't exactly like that. >> Could fib_release_info() be interrupted by BH really? > > Absolutely, yes it can. What makes yo

Re: [PATCH] locking bug in fib_semantics.c

2006-08-21 Thread Jarek Poplawski
On 17-08-2006 11:36, Alexey Kuznetsov wrote: > Hello! > > [IPV4]: severe locking bug in fib_semantics.c > > The patch is for net-2.6.19, but the bug is present in all the kernels > since yore. > > Found in 2.4 by Yixin Pan <[EMAIL PROTECTED]>. Why do we need lockdep, > when sharp-sighted eyes are a

Re: [PATCH] locking bug in fib_semantics.c

2006-08-21 Thread David Miller
From: Jarek Poplawski <[EMAIL PROTECTED]> Date: Mon, 21 Aug 2006 10:16:43 +0200 > On 17-08-2006 11:36, Alexey Kuznetsov wrote: > > Hello! > > > > [IPV4]: severe locking bug in fib_semantics.c > > > > The patch is for net-2.6.19, but the bug is present in all the kernels > > since yore. > > > > Fou

Re: [PATCH] locking bug in fib_semantics.c

2006-08-17 Thread David Miller
From: Alexey Kuznetsov <[EMAIL PROTECTED]> Date: Thu, 17 Aug 2006 13:36:15 +0400 > Found in 2.4 by Yixin Pan <[EMAIL PROTECTED]>. Why do we need lockdep, > when sharp-sighted eyes are available? :-) Lockdep can only tell us about code paths which actually have been run, so it shows that nobody ru

[PATCH] locking bug in fib_semantics.c

2006-08-17 Thread Alexey Kuznetsov
Hello! [IPV4]: severe locking bug in fib_semantics.c The patch is for net-2.6.19, but the bug is present in all the kernels since yore. Found in 2.4 by Yixin Pan <[EMAIL PROTECTED]>. Why do we need lockdep, when sharp-sighted eyes are available? :-) > When I read fib_semantics.c of Linux-2.4.32