Messages in this thread Patch in this message | | | Date | Tue, 2 Dec 2003 10:37:49 -0800 (PST) | From | Linus Torvalds <> | Subject | Re: IDE-SCSI oops in 2.6.0-test11 |
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On Tue, 2 Dec 2003 ross.alexander@uk.neceur.com wrote: > > I can't get the source, otherwise I would have compiled it against > 2.6.0. However I don't find this point particularly relevant since > 2.6.0 should be backward compatible with 2.4,0, atleast at the binary > level. > > I tried the earlier versions of dvdrtools and cdrtools and their didn't > like ide-cd. This version (cdrecord-dvdpro) does but it still don't > alter the fact that while using ide-scsi is no longer recommended, it > still should work.
Well, we're trying, but nobody has had a lot of luck with it.
However, your particular case looks pretty straightforward:
> Here the the oops again. > > Dec 2 12:02:46 mig27 kernel: Unable to handle kernel NULL pointer dereference at virtual address 00000000 > Dec 2 12:02:46 mig27 kernel: printing eip: > Dec 2 12:02:46 mig27 kernel: 00000000
Somebody jumped through a NULL pointer, and it was:
> Dec 2 12:02:46 mig27 kernel: Process cdrecord-prodvd (pid: 369, threadinfo=e4160000 task=f65d4100) > Dec 2 12:02:46 mig27 kernel: Call Trace: > Dec 2 12:02:46 mig27 kernel: [<f9859b1b>] idescsi_transfer_pc+0x11b/0x120 [ide_scsi]
That's the code that does:
... if (test_bit (PC_DMA_OK, &pc->flags)) { set_bit (PC_DMA_IN_PROGRESS, &pc->flags); (void) (HWIF(drive)->ide_dma_begin(drive)); } ...
and it looks like the PC_DMA_OK flag is incorrect.
Doing a bit more digging shows that "idescsi_issue_pc()" seems to use some variables without ever actually _initializing_ them. How about this trivial one-liner? Does that make it work for you?
Jens? Comments?
Linus
--- ===== drivers/scsi/ide-scsi.c 1.33 vs edited ===== --- 1.33/drivers/scsi/ide-scsi.c Tue Nov 18 23:40:45 2003 +++ edited/drivers/scsi/ide-scsi.c Tue Dec 2 10:36:33 2003 @@ -516,6 +516,7 @@ pc->actually_transferred=0; /* We haven't transferred any data yet */ pc->current_position=pc->buffer; bcount.all = IDE_MIN(pc->request_transfer, 63 * 1024); /* Request to transfer the entire buffer at once */ + feature.all = 0;
if (drive->using_dma && rq->bio) { if (test_bit(PC_WRITING, &pc->flags)) - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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