6.5-stable review patch. If anyone has any objections, please let me know.
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From: Matthew Wilcox (Oracle) willy@infradead.org
commit 863a8eb3f27098b42772f668e3977ff4cae10b04 upstream.
The folio conversion changed the behaviour of shmem_sg_alloc_table() to put the entire length of the last folio into the sg list, even if the sg list should have been shorter. gen8_ggtt_insert_entries() relied on the list being the right length and would overrun the end of the page tables. Other functions may also have been affected.
Clamp the length of the last entry in the sg list to be the expected length.
Signed-off-by: Matthew Wilcox (Oracle) willy@infradead.org Fixes: 0b62af28f249 ("i915: convert shmem_sg_free_table() to use a folio_batch") Cc: stable@vger.kernel.org # 6.5.x Link: https://gitlab.freedesktop.org/drm/intel/-/issues/9256 Link: https://lore.kernel.org/lkml/6287208.lOV4Wx5bFT@natalenko.name/ Reported-by: Oleksandr Natalenko oleksandr@natalenko.name Tested-by: Oleksandr Natalenko oleksandr@natalenko.name Reviewed-by: Andrzej Hajda andrzej.hajda@intel.com Signed-off-by: Andrzej Hajda andrzej.hajda@intel.com Link: https://patchwork.freedesktop.org/patch/msgid/20230919194855.347582-1-willy@... (cherry picked from commit 26a8e32e6d77900819c0c730fbfb393692dbbeea) Signed-off-by: Rodrigo Vivi rodrigo.vivi@intel.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/gpu/drm/i915/gem/i915_gem_shmem.c | 11 +++++++---- 1 file changed, 7 insertions(+), 4 deletions(-)
diff --git a/drivers/gpu/drm/i915/gem/i915_gem_shmem.c b/drivers/gpu/drm/i915/gem/i915_gem_shmem.c index 8f1633c3fb93..73a4a4eb29e0 100644 --- a/drivers/gpu/drm/i915/gem/i915_gem_shmem.c +++ b/drivers/gpu/drm/i915/gem/i915_gem_shmem.c @@ -100,6 +100,7 @@ int shmem_sg_alloc_table(struct drm_i915_private *i915, struct sg_table *st, st->nents = 0; for (i = 0; i < page_count; i++) { struct folio *folio; + unsigned long nr_pages; const unsigned int shrink[] = { I915_SHRINK_BOUND | I915_SHRINK_UNBOUND, 0, @@ -150,6 +151,8 @@ int shmem_sg_alloc_table(struct drm_i915_private *i915, struct sg_table *st, } } while (1);
+ nr_pages = min_t(unsigned long, + folio_nr_pages(folio), page_count - i); if (!i || sg->length >= max_segment || folio_pfn(folio) != next_pfn) { @@ -157,13 +160,13 @@ int shmem_sg_alloc_table(struct drm_i915_private *i915, struct sg_table *st, sg = sg_next(sg);
st->nents++; - sg_set_folio(sg, folio, folio_size(folio), 0); + sg_set_folio(sg, folio, nr_pages * PAGE_SIZE, 0); } else { /* XXX: could overflow? */ - sg->length += folio_size(folio); + sg->length += nr_pages * PAGE_SIZE; } - next_pfn = folio_pfn(folio) + folio_nr_pages(folio); - i += folio_nr_pages(folio) - 1; + next_pfn = folio_pfn(folio) + nr_pages; + i += nr_pages - 1;
/* Check that the i965g/gm workaround works. */ GEM_BUG_ON(gfp & __GFP_DMA32 && next_pfn >= 0x00100000UL);