[PATCH RFC v2 15/27] arm64: mte: Check that tag storage blocks are in the same zone

Alexandru Elisei
2023-11-19T16:59:29Z

alloc_contig_range() requires that the requested pages are in the same
zone. Check that this is indeed the case before initializing the tag
storage blocks.

Signed-off-by: Alexandru Elisei <alexandru.elisei@arm.com>
---
arch/arm64/kernel/mte_tag_storage.c | 33 +++++++++++++++++++++++++++++
1 file changed, 33 insertions(+)

diff --git a/arch/arm64/kernel/mte_tag_storage.c b/arch/arm64/kernel/mte_tag_storage.c
index 8b9bedf7575d..fd63430d4dc0 100644
--- a/arch/arm64/kernel/mte_tag_storage.c
+++ b/arch/arm64/kernel/mte_tag_storage.c
@@ -265,6 +265,35 @@ void __init mte_tag_storage_init(void)
}
}

+/* alloc_contig_range() requires all pages to be in the same zone. */
+static int __init mte_tag_storage_check_zone(void)
+{
+ struct range *tag_range;
+ struct zone *zone;
+ unsigned long pfn;
+ u32 block_size;
+ int i, j;
+
+ for (i = 0; i < num_tag_regions; i++) {
+ block_size = tag_regions[i].block_size;
+ if (block_size == 1)
+ continue;
+
+ tag_range = &tag_regions[i].tag_range;
+ for (pfn = tag_range->start; pfn <= tag_range->end; pfn += block_size) {
+ zone = page_zone(pfn_to_page(pfn));
+ for (j = 1; j < block_size; j++) {
+ if (page_zone(pfn_to_page(pfn + j)) != zone) {
+ pr_err("Tag storage block pages in different zones");
+ return -EINVAL;
+ }
+ }
+ }
+ }
+
+ return 0;
+}
+
static int __init mte_tag_storage_activate_regions(void)
{
phys_addr_t dram_start, dram_end;
@@ -321,6 +350,10 @@ static int __init mte_tag_storage_activate_regions(void)
goto out_disabled;
}

+ ret = mte_tag_storage_check_zone();
+ if (ret)
+ goto out_disabled;
+
for (i = 0; i < num_tag_regions; i++) {
tag_range = &tag_regions[i].tag_range;
for (pfn = tag_range->start; pfn <= tag_range->end; pfn += pageblock_nr_pages)
--
2.42.1