Date: Sat, 18 Oct 1997 19:32:07 +0200 From: j@uriah.heep.sax.de (J Wunsch) To: freebsd-scsi@FreeBSD.ORG Subject: Re: Cannot happen? Message-ID: <19971018193207.SI11932@uriah.heep.sax.de> In-Reply-To: <199710181438.AAA28420@godzilla.zeta.org.au>; from Bruce Evans on Oct 19, 1997 00:38:58 %2B1000 References: <199710181438.AAA28420@godzilla.zeta.org.au>
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As Bruce Evans wrote: > >But the questions is: how can this happen? > > 1. a slice table or label can override the driver's idea of the disk size. > This is a feature. (Not the case.) > 2. the frobbing of the sector size in the current sd and od is still broken. > It allows writing beyond the disk. This shouldn't happen for paging. This seems to be the problem. > 3. some drivers don't do any bounds checking for the raw partition. This > is not a problem for sd and the raw partition shouldn't be used for > paging. It wasn't happening together with paging. The last block of this disk was assigned to my /home filesystem. I think the error message from the pager was due to the IO being done through mmap() (or due to the similar effect of the merged VM/buffer cache). > >Ain't the driver supposed > >to limit the requests before calling the SCSI layers? Ain't the > > Sort of. SCSI drivers can probably rely on the device to do the checking. But well, they should return a short read instead of blasting the console with error messages, and even worse, delivering a signal to the application. -- cheers, J"org joerg_wunsch@uriah.heep.sax.de -- http://www.sax.de/~joerg/ -- NIC: JW11-RIPE Never trust an operating system you don't have sources for. ;-)
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