From: Pavel Machek <pavel@ucw.cz>
To: Linus Torvalds <torvalds@osdl.org>
Cc: Srivatsa Vaddagiri <vatsa@in.ibm.com>,
Kernel Mailing List <linux-kernel@vger.kernel.org>,
manfred@colorfullife.com, rusty@au1.ibm.com,
Andrew Morton <akpm@osdl.org>
Subject: Re: BUG in x86 do_page_fault? [was Re: in_atomic doesn't count local_irq_disable?]
Date: Sun, 4 Jan 2004 15:57:36 +0100 [thread overview]
Message-ID: <20040104145736.GA11198@elf.ucw.cz> (raw)
In-Reply-To: <Pine.LNX.4.58.0312311104180.2065@home.osdl.org>
Hi!
> > in_atomic() doesn't seem to return true
> > in code sections where IRQ's have been disabled (using
> > local_irq_disable).
> >
> > As a result, I think do_page_fault() on x86 needs to
> > be updated to note this fact:
>
> NO.
>
> Please don't do this, it will result in some _really_ nasty problems with
> X and other programs that potentially disable interrupts in user
> space.
If user program causes page fault with interrupts disabled, it is
certainly buggy, right?
Either the user program does not really need irq disabled or it does
need that but page fault just broke its guarantees (=> severe problems
ahead).
In both cases there's user program that needs fixing.
Pavel
--
When do you have a heart between your knees?
[Johanka's followup: and *two* hearts?]
next prev parent reply other threads:[~2004-01-04 14:56 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2003-12-29 15:13 in_atomic doesn't count local_irq_disable? Manfred Spraul
2003-12-30 13:26 ` Srivatsa Vaddagiri
2003-12-31 13:29 ` BUG in x86 do_page_fault? [was Re: in_atomic doesn't count local_irq_disable?] Srivatsa Vaddagiri
2003-12-31 19:08 ` Linus Torvalds
2004-01-04 14:57 ` Pavel Machek [this message]
2004-01-04 20:43 ` Linus Torvalds
2004-03-29 15:43 ` Linus Torvalds
2004-03-29 15:42 ` Pavel Machek
2003-12-31 13:35 ` [lhcs-devel] Re: in_atomic doesn't count local_irq_disable? Srivatsa Vaddagiri
2004-01-02 0:52 ` Manfred Spraul
2004-01-02 10:56 ` Srivatsa Vaddagiri
2004-01-02 14:00 ` Srivatsa Vaddagiri
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