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From: sarima@tdatirv.UUCP (Stanley Friesen)
Newsgroups: comp.unix.internals,comp.unix.wizards
Subject: Re: Help with 4.3 mod to kill uninteruptable procs.
Message-ID: <151@tdatirv.UUCP>
Date: 22 Feb 91 19:57:36 GMT
References: <1991Feb19.001941.29928@lynx.CS.ORST.EDU> <4066@stl.stc.co.uk> <19065@rpp386.cactus.org> <1991Feb21.145705.27763@cbnews.att.com>
Reply-To: sarima@tdatirv.UUCP (Stanley Friesen)
Followup-To: comp.unix.internals
Organization: Teradata Corp., Irvine
Lines: 17

In article <1991Feb21.145705.27763@cbnews.att.com> rock@cbnews.att.com (Y. Rock Lee) writes:
>Forcibly awaking a process doing read/write (DMA transter) will either
>give the process a buffer with garbage data or throw away a buffer
>containing valid data. How can this trash someone else's memory?

Scenario - forcibly wake-up a process waiting on a slow device,
	process mucks about with unfilled buffer, and *releases* it.
	process probably dies due to signal the woke it up.
	another process acquires the buffer from the free pool
		(Perhaps intending to use it for paging)
	slow device finally finishes, putting results into buffer.
	new process returns the buffer or (worse) uses it as a new page.

	VOILA - corrupted stuff in the new process.
-- 
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uunet!tdatirv!sarima				(Stanley Friesen)


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