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authorLinus Torvalds <torvalds@linux-foundation.org>2022-05-27 21:29:35 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2022-05-27 21:29:35 +0300
commit77fb622de1393b1d54f24f4f7ed98f84feeda502 (patch)
treec23243c07995b6a906b90ce4c0bfc1c514aab61f /mm
parent6f664045c8688c40ad0591abd6ab89db9ecd7945 (diff)
parent24c8e27e63224ce832b4723cb60632d3eddb55de (diff)
downloadlinux-77fb622de1393b1d54f24f4f7ed98f84feeda502.tar.xz
Merge tag 'mm-hotfixes-stable-2022-05-27' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Pull hotfixes from Andrew Morton: "Six hotfixes. The page_table_check one from Miaohe Lin is considered a minor thing so it isn't marked for -stable. The remainder address pre-5.19 issues and are cc:stable" * tag 'mm-hotfixes-stable-2022-05-27' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: mm/page_table_check: fix accessing unmapped ptep kexec_file: drop weak attribute from arch_kexec_apply_relocations[_add] mm/page_alloc: always attempt to allocate at least one page during bulk allocation hugetlb: fix huge_pmd_unshare address update zsmalloc: fix races between asynchronous zspage free and page migration Revert "mm/cma.c: remove redundant cma_mutex lock"
Diffstat (limited to 'mm')
-rw-r--r--mm/cma.c4
-rw-r--r--mm/hugetlb.c9
-rw-r--r--mm/page_alloc.c4
-rw-r--r--mm/page_table_check.c2
-rw-r--r--mm/zsmalloc.c37
5 files changed, 47 insertions, 9 deletions
diff --git a/mm/cma.c b/mm/cma.c
index eaa4b5c920a2..4a978e09547a 100644
--- a/mm/cma.c
+++ b/mm/cma.c
@@ -37,6 +37,7 @@
struct cma cma_areas[MAX_CMA_AREAS];
unsigned cma_area_count;
+static DEFINE_MUTEX(cma_mutex);
phys_addr_t cma_get_base(const struct cma *cma)
{
@@ -468,9 +469,10 @@ struct page *cma_alloc(struct cma *cma, unsigned long count,
spin_unlock_irq(&cma->lock);
pfn = cma->base_pfn + (bitmap_no << cma->order_per_bit);
+ mutex_lock(&cma_mutex);
ret = alloc_contig_range(pfn, pfn + count, MIGRATE_CMA,
GFP_KERNEL | (no_warn ? __GFP_NOWARN : 0));
-
+ mutex_unlock(&cma_mutex);
if (ret == 0) {
page = pfn_to_page(pfn);
break;
diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index 01f0e2e5ab48..7c468ac1d069 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -6755,7 +6755,14 @@ int huge_pmd_unshare(struct mm_struct *mm, struct vm_area_struct *vma,
pud_clear(pud);
put_page(virt_to_page(ptep));
mm_dec_nr_pmds(mm);
- *addr = ALIGN(*addr, HPAGE_SIZE * PTRS_PER_PTE) - HPAGE_SIZE;
+ /*
+ * This update of passed address optimizes loops sequentially
+ * processing addresses in increments of huge page size (PMD_SIZE
+ * in this case). By clearing the pud, a PUD_SIZE area is unmapped.
+ * Update address to the 'last page' in the cleared area so that
+ * calling loop can move to first page past this area.
+ */
+ *addr |= PUD_SIZE - PMD_SIZE;
return 1;
}
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index bc93a82e51e6..149f2ab5063b 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -5324,8 +5324,8 @@ unsigned long __alloc_pages_bulk(gfp_t gfp, int preferred_nid,
page = __rmqueue_pcplist(zone, 0, ac.migratetype, alloc_flags,
pcp, pcp_list);
if (unlikely(!page)) {
- /* Try and get at least one page */
- if (!nr_populated)
+ /* Try and allocate at least one page */
+ if (!nr_account)
goto failed_irq;
break;
}
diff --git a/mm/page_table_check.c b/mm/page_table_check.c
index 3692bea2ea2c..e2062748791a 100644
--- a/mm/page_table_check.c
+++ b/mm/page_table_check.c
@@ -234,11 +234,11 @@ void __page_table_check_pte_clear_range(struct mm_struct *mm,
pte_t *ptep = pte_offset_map(&pmd, addr);
unsigned long i;
- pte_unmap(ptep);
for (i = 0; i < PTRS_PER_PTE; i++) {
__page_table_check_pte_clear(mm, addr, *ptep);
addr += PAGE_SIZE;
ptep++;
}
+ pte_unmap(ptep - PTRS_PER_PTE);
}
}
diff --git a/mm/zsmalloc.c b/mm/zsmalloc.c
index 9152fbde33b5..5d5fc04385b8 100644
--- a/mm/zsmalloc.c
+++ b/mm/zsmalloc.c
@@ -1718,11 +1718,40 @@ static enum fullness_group putback_zspage(struct size_class *class,
*/
static void lock_zspage(struct zspage *zspage)
{
- struct page *page = get_first_page(zspage);
+ struct page *curr_page, *page;
- do {
- lock_page(page);
- } while ((page = get_next_page(page)) != NULL);
+ /*
+ * Pages we haven't locked yet can be migrated off the list while we're
+ * trying to lock them, so we need to be careful and only attempt to
+ * lock each page under migrate_read_lock(). Otherwise, the page we lock
+ * may no longer belong to the zspage. This means that we may wait for
+ * the wrong page to unlock, so we must take a reference to the page
+ * prior to waiting for it to unlock outside migrate_read_lock().
+ */
+ while (1) {
+ migrate_read_lock(zspage);
+ page = get_first_page(zspage);
+ if (trylock_page(page))
+ break;
+ get_page(page);
+ migrate_read_unlock(zspage);
+ wait_on_page_locked(page);
+ put_page(page);
+ }
+
+ curr_page = page;
+ while ((page = get_next_page(curr_page))) {
+ if (trylock_page(page)) {
+ curr_page = page;
+ } else {
+ get_page(page);
+ migrate_read_unlock(zspage);
+ wait_on_page_locked(page);
+ put_page(page);
+ migrate_read_lock(zspage);
+ }
+ }
+ migrate_read_unlock(zspage);
}
static int zs_init_fs_context(struct fs_context *fc)