On Thu, Jun 11, 2020 at 11:07:11AM +0100, Laurence Tratt wrote:
> The recent DRM update has fixed one long-ish-standing bug for me where Xorg
> sometimes would get stuck while executing Xsession (I could never work out
> why) which is really good!
>
> However I've now had the following kernel panic several times:
>
> kernel: page fault trap, code=0
> Stopped at intel_partial_pages+0xf4: moq 0x58,%rsi
>
> Unfortunately that also seems to take out my keyboard at ddb so I have no
> further information beyond my dmesg :/
Try this, the code in question does
sg_set_page(sg, NULL, I915_GTT_PAGE_SIZE, 0);
sg_dma_address(sg) =
i915_gem_object_get_dma_address(obj, src_idx);
sg_dma_len(sg) = I915_GTT_PAGE_SIZE;
VM_PAGE_TO_PHYS() will attempt to deref NULL.
Index: sys/dev/pci/drm/include/linux/scatterlist.h
===================================================================
RCS file: /cvs/src/sys/dev/pci/drm/include/linux/scatterlist.h,v
retrieving revision 1.2
diff -u -p -r1.2 scatterlist.h
--- sys/dev/pci/drm/include/linux/scatterlist.h 8 Jun 2020 04:48:15 -0000
1.2
+++ sys/dev/pci/drm/include/linux/scatterlist.h 11 Jun 2020 10:54:05 -0000
@@ -115,7 +115,8 @@ sg_set_page(struct scatterlist *sgl, str
unsigned int length, unsigned int offset)
{
sgl->__page = page;
- sgl->dma_address = VM_PAGE_TO_PHYS(page);
+ if (page != NULL)
+ sgl->dma_address = VM_PAGE_TO_PHYS(page);
sgl->offset = offset;
sgl->length = length;
sgl->end = false;
