high_memory address in /proc/dri/*/vma

[Ben Hutchings]

[Re-sent to the right address, I hope.]

Kees, in commit 01e2f533a234dc62d16c0d3d4fb9d71cf1ce50c3 ("drm: do not
leak kernel addresses via /proc/dri/*/vma") you changed the logging of
high_memory:

-       seq_printf(m, "vma use count: %d, high_memory = %p, 0x%08llx\n",
+       seq_printf(m, "vma use count: %d, high_memory = %pK, 0x%pK\n",
                   atomic_read(&dev->vma_count),
-                  high_memory, (u64)virt_to_phys(high_memory));
+                  high_memory, (void *)virt_to_phys(high_memory));

This doesn't make sense because the physical address may be truncated
(in theory at least).

I think it would make more sense to make this entire file readable by
root only, but I don't know whether anything depends on being able to
read it.  Its existence is conditional on DRM_DEBUG_CODE != 0 but that
is always true at the moment.

Ben.

-- 
Ben Hutchings
Humans are not rational beings; they are rationalising beings.