Bug 166544
Summary: | 2.6.9-16.ELsmp null pointer dereference in __bounce_end_io_read on x86_64 | ||||||
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Product: | Red Hat Enterprise Linux 4 | Reporter: | Norm Murray <nmurray> | ||||
Component: | kernel | Assignee: | Larry Woodman <lwoodman> | ||||
Status: | CLOSED ERRATA | QA Contact: | Brian Brock <bbrock> | ||||
Severity: | medium | Docs Contact: | |||||
Priority: | medium | ||||||
Version: | 4.0 | CC: | jbaron | ||||
Target Milestone: | --- | ||||||
Target Release: | --- | ||||||
Hardware: | x86_64 | ||||||
OS: | Linux | ||||||
Whiteboard: | |||||||
Fixed In Version: | RHSA-2006-0132 | Doc Type: | Bug Fix | ||||
Doc Text: | Story Points: | --- | |||||
Clone Of: | Environment: | ||||||
Last Closed: | 2006-03-07 19:37:10 UTC | Type: | --- | ||||
Regression: | --- | Mount Type: | --- | ||||
Documentation: | --- | CRM: | |||||
Verified Versions: | Category: | --- | |||||
oVirt Team: | --- | RHEL 7.3 requirements from Atomic Host: | |||||
Cloudforms Team: | --- | Target Upstream Version: | |||||
Embargoed: | |||||||
Bug Depends On: | |||||||
Bug Blocks: | 168430 | ||||||
Attachments: |
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Description
Norm Murray
2005-08-23 06:52:38 UTC
bounce code can get called even on 64-bit system, if the device can't dma to the requested address. ok... do doing bounce isn't necessarily odd... except on x86_64 we can only bounce through the isa_dma_pool because without highmem we don't initialize any other bounce pool. Not directly related to the panic is a side issue... on this brand new hardware, why am I limited to isa range for dma... in part, we don't create a lowmem dma pool because there is no highmem region on the system. Another reason would seem to be that the scsi (sata) device is not being detected as being able to dma to the entire 4gb of ram on the system... could be bad support for the device, or bad bios, or bad detection code... As I continue to dig... Reproduction simply takes cat'ing a file on the lvm array setup in this system, while access to the disk which is not part of the lvm array doesn't seem to have any issues. Haven't tracked down how yet, but it appears that IO from the lvm array is not being flagged as capable to do dma to all of memory, even though the underlying device can - and with no highmem zone, the dma must go through the isa dma region. So... took lvm apart and used the bare drives... individually, they all work fine. So there seems to be something in the lvm path that is requiring the bounce IO, and having problems therein, which is not required by the bare devices. Created attachment 122807 [details]
patch to highmem.c
Patch from upstream via Dell in IT 85468
An advisory has been issued which should help the problem described in this bug report. This report is therefore being closed with a resolution of ERRATA. For more information on the solution and/or where to find the updated files, please follow the link below. You may reopen this bug report if the solution does not work for you. http://rhn.redhat.com/errata/RHSA-2006-0132.html |