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From: Jeff Dike <jdike@addtoit.com>
To: Bodo Stroesser <bstroesser@fujitsu-siemens.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>,
	linux-kernel@vger.kernel.org,
	user-mode-linux-devel@lists.sourceforge.net
Subject: Re: [uml-devel] Re: [RFC] PATCH 3/4 - Time virtualization : PTRACE_SYSCALL_MASK
Date: Tue, 25 Apr 2006 14:32:51 -0400	[thread overview]
Message-ID: <20060425183251.GB22977@ccure.user-mode-linux.org> (raw)
In-Reply-To: <444797F8.6020509@fujitsu-siemens.com>

On Thu, Apr 20, 2006 at 04:17:28PM +0200, Bodo Stroesser wrote:
> Shouldn't 'len' better be the number of bits in the mask than the number of 
> chars?

Yup.

> OTOH, I think UML shouldn't send the entire mask, but relevant part only. 
> The missing end is filled with 0xff by host anyway. So it would be
> enough to send the mask up to the highest bit representing a
> syscall, that needs to be executed by host.  (currently, that is
> __NR_gettimeofday). If UML would do so, no more problem results from
> UML having a higher NR_syscall than the host (as long as the new
> syscalls are to be intercepted and executed by UML)

Yup, that was part of the intent of sending in the mask length.

> A greater problem might be a process in UML, that calls an invalid syscall 
> number. AFAICS syscall number (orig_eax) isn't checked before it is
> used in do_syscall_trace to address syscall_mask. This might result
> in a crash. 

Yeah, this needs fixing.

				Heff

  reply	other threads:[~2006-04-25 20:45 UTC|newest]

Thread overview: 26+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2006-04-13 17:20 [RFC] PATCH 3/4 - Time virtualization : PTRACE_SYSCALL_MASK Jeff Dike
2006-04-18 12:57 ` Pavel Machek
2006-04-26 18:38   ` Jeff Dike
2006-04-20  9:05 ` Heiko Carstens
2006-04-20 14:17   ` [uml-devel] " Bodo Stroesser
2006-04-25 18:32     ` Jeff Dike [this message]
2006-04-26 20:26     ` Charles P. Wright
2006-04-26 19:40       ` Jeff Dike
2006-04-26 21:29         ` Charles P. Wright
2006-04-21 18:16   ` Blaisorblade
2006-04-21 18:38     ` Blaisorblade
2006-04-22  7:06     ` Heiko Carstens
2006-04-22  8:32       ` Blaisorblade
2006-04-25 15:59       ` Jeff Dike
2006-04-21 18:34 ` [uml-devel] " Blaisorblade
2006-04-25 16:29   ` Jeff Dike
2006-04-26 15:47     ` Blaisorblade
2006-04-26 15:46       ` Jeff Dike
2006-04-28 20:28         ` Blaisorblade
2006-04-29  1:49           ` Jeff Dike
2006-05-01 13:51             ` Daniel Jacobowitz
2006-05-01 13:45               ` Jeff Dike
2006-05-01 15:01                 ` Daniel Jacobowitz
2006-04-29  8:49           ` Heiko Carstens
2006-05-01 17:02             ` Jeff Dike
2006-05-02  6:57               ` Heiko Carstens

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