Subject: [PATCH] Missing critical phys_to_virt in lib/swiotlb.c From: David Moore Date: Sun, 04 Feb 2007 13:39:40 -0500 From: David Moore Adds missing call to phys_to_virt() in the lib/swiotlb.c:swiotlb_sync_sg() function. Without this change, a kernel panic will always occur whenever a SWIOTLB bounce buffer from a scatter-gather list gets synced. Signed-off-by: David Moore --- This change was originally part of a larger patch by Jan Beulich, which was more extensive and doesn't look destined to make it into 2.6.20: http://kernel.org/pub/linux/kernel/people/akpm/patches/2.6/2.6.20-rc6/2.6.20-rc6-mm3/broken-out/ia64-swiotlb-bug-fixes.patch However, considering the severity of this one-liner bug, I would like to request that this simplified patch make it into 2.6.20, despite how close we are to the final cut. It fixes real crashes: http://lists.opensuse.org/opensuse-bugs/2006-12/msg02943.html http://qa.mandriva.com/show_bug.cgi?id=28224 http://www.pchdtv.com/forum/viewtopic.php?t=2063&sid=a959a14a4c2db0eebaab7b0df56103ce --- linux-2.6.19.x86_64/lib/swiotlb.c.orig 2007-02-04 13:18:41.000000000 -0500 +++ linux-2.6.19.x86_64/lib/swiotlb.c 2007-02-04 13:19:43.000000000 -0500 @@ -750,7 +750,7 @@ swiotlb_sync_sg(struct device *hwdev, st for (i = 0; i < nelems; i++, sg++) if (sg->dma_address != SG_ENT_PHYS_ADDRESS(sg)) - sync_single(hwdev, (void *) sg->dma_address, + sync_single(hwdev, phys_to_virt(sg->dma_address), sg->dma_length, dir, target); }