From: Jim Cromie <[email protected]> The standard roundup_pow_of_two() and rounddown_pow_of_two() macros use unsigned long internally, which on 32-bit architectures (like arm32) is a 32-bit type.
drm_test_buddy_alloc_exceeds_max_order() uses these on a u64 value, where they silently truncate the 10GB allocation, giving unexpected success in DRM-CI. (see below the snip). Fix this by replacing the those macros with the safe 64-bit power-of-two equivalents added in the previous patch. Signed-off-by: Jim Cromie <[email protected]> Signed-off-by: David Gow <[email protected]> --- This should actually be version 13, I think, as it's just a rebase of v12 here, where it was part of a large series of fixups: https://lore.kernel.org/all/[email protected]/ The major changes since that version are: - Add the helper functions rounddown_pow_of_two64() and roundup_pow_of_two64() (see patch 1) instead of open-coding them - Rebase now that the buddy allocator lives in drivers/gpu/buddy.c instead of drivers/gpu/drm/drm_buddy.c This is still breaking the gpu_test_buddy_alloc_exceeds_max_order KUnit test on 32-bit systems: [09:01:26] # gpu_test_buddy_alloc_exceeds_max_order: EXPECTATION FAILED at drivers/gpu/tests/gpu_buddy_test.c:1429 [09:01:26] Expected err == -22, but [09:01:26] err == 0 (0x0) [09:01:26] WARNING: drivers/gpu/buddy.c:508 at gpu_buddy_fini+0x244/0x2e0, CPU#0: kunit_try_catch/1595 [09:01:26] # gpu_test_buddy_alloc_exceeds_max_order: drivers/gpu/buddy.c:508: gpu_buddy_assert(gpu_buddy_block_is_free(mm->roots[i])) [09:01:26] WARNING: drivers/gpu/buddy.c:516 at gpu_buddy_fini+0x284/0x2e0, CPU#0: kunit_try_catch/1595 [09:01:26] # gpu_test_buddy_alloc_exceeds_max_order: drivers/gpu/buddy.c:508: gpu_buddy_assert(gpu_buddy_block_is_free(mm->roots[i])) [09:01:26] WARNING: drivers/gpu/buddy.c:516 at gpu_buddy_fini+0x284/0x2e0, CPU#0: kunit_try_catch/1595 [09:01:26] # gpu_test_buddy_alloc_exceeds_max_order: drivers/gpu/buddy.c:519: gpu_buddy_assert(!mm->used_scoreboard[i]) [09:01:26] [FAILED] gpu_test_buddy_alloc_exceeds_max_order Cheers, -- David --- drivers/gpu/buddy.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/gpu/buddy.c b/drivers/gpu/buddy.c index a5553fcec28c..64f41f1fe908 100644 --- a/drivers/gpu/buddy.c +++ b/drivers/gpu/buddy.c @@ -1193,7 +1193,7 @@ static int __alloc_contig_try_harder(struct gpu_buddy *mm, u64 modify_size; int err; - modify_size = rounddown_pow_of_two(size); + modify_size = rounddown_pow_of_two64(size); order = ilog2(modify_size) - ilog2(mm->chunk_size); if (order == 0) return -ENOSPC; @@ -1440,7 +1440,7 @@ int gpu_buddy_alloc_blocks(struct gpu_buddy *mm, /* Roundup the size to power of 2 */ if (flags & GPU_BUDDY_CONTIGUOUS_ALLOCATION) { - size = roundup_pow_of_two(size); + size = roundup_pow_of_two64(size); min_block_size = size; /* * Normalize the requested size to min_block_size for regular allocations. -- 2.55.0
