Messages in this thread | | | Date | Fri, 03 Feb 2006 14:38:11 -0600 | From | Mike Christie <> | Subject | Re: [PATCH] st: don't doublefree pages from scatterlist |
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Hugh Dickins wrote: > On some architectures, mapping the scatterlist may coalesce entries: > if that coalesced list is then used for freeing the pages afterwards, > there's a danger that pages may be doubly freed (and others leaked). > > Fix SCSI Tape's sgl_unmap_user_pages by freeing from the pagelist used > in sgl_map_user_pages. Fixes Ryan Richter's crash on x86_64, with Bad > page state mapcount 2 from sgl_unmap_user_pages, and consequent mayhem. >
Is this crash occuring with 2.6.16-rc1? I ask becuase in that kernel the scatterlist passed into scsi_execute_async
if (scsi_execute_async(STp->device, cmd, direction, &((STp->buffer)->sg[0]), bytes,
is not the same one that gets send down to the device/HBA.
scsi_execute_async takes the scatterlist passed to it from st or sg, uses it as a hint to build a request + bios, then later when the request is sent to the device a new scatterlist is sent to the device and the device does the pci/dma operation on that scatterlist from the block/scsi layer. - 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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