mm/mmu_gather: fix flushing ranges with 4 GiB or larger

__tlb_adjust_range() takes the size of the range which has to be flushed
as an unsigned int. Its callers, tlb_flush_{pte,pmd,pud,p4d}_range(), get
and pass an unsigned long. Consequently, a range that is 4 GiB or larger
gets truncated, possibly to 0.

On arm64 with hugetlb, a 64k kernel can have 16 GiB hugetlb folios
mapped contiguously at the PMD level and flush them when unmapping, and a
16k kernel can flush 64 GiB PUDs through tlb_unshare_pmd_ptdesc(). So
at least these two scenarios are affected.

Fix it by flushing the proper range instead of the truncated one by
properly using "unsigned long" for range_size.

Fix generated by an LLM and sent by Josef Bacik in private.

Fixes: b528e4b6405b ("mm/hugetlb: add tlb_remove_hugetlb_entry for handling hugetlb pages")
Fixes: 8ce720d5bd91 ("mm/hugetlb: fix excessive IPI broadcasts when unsharing PMD tables using mmu_gather")
Cc: stable@vger.kernel.org
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Acked-by: Lorenzo Stoakes (ARM) <ljs@kernel.org>
[ david: use two-tab indent, simplify description ]
Reviewed-by: Qi Zheng <qi.zheng@linux.dev>
Reviewed-by: Gregory Price (Meta) <gourry@gourry.net>
Tested-by: Gregory Price (Meta) <gourry@gourry.net>
Reviewed-by: Dev Jain <dev.jain@arm.com>
Reviewed-by: Muchun Song <muchun.song@linux.dev>
Reviewed-by: Pedro Falcato <pfalcato@suse.de>
Reviewed-by: SJ Park <sj@kernel.org>
Tested-by: Muhammad Usama Anjum <usama.anjum@arm.com>
Link: https://patch.msgid.link/20261031-fixes_core-v3-27-d6437171ecc3@kernel.org
Signed-off-by: David Hildenbrand (Arm) <david@kernel.org>

0 files changed, 0 insertions, 0 deletions