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Message-ID: <20250116061657.227027-2-mawupeng1@huawei.com>
Date: Thu, 16 Jan 2025 14:16:55 +0800
From: Wupeng Ma <mawupeng1@...wei.com>
To: <akpm@...ux-foundation.org>, <david@...hat.com>, <osalvador@...e.de>,
<nao.horiguchi@...il.com>, <linmiaohe@...wei.com>, <mhocko@...e.com>
CC: <mawupeng1@...wei.com>, <linux-mm@...ck.org>,
<linux-kernel@...r.kernel.org>
Subject: [PATCH v2 1/3] mm: memory-failure: update ttu flag inside unmap_poisoned_folio
From: Ma Wupeng <mawupeng1@...wei.com>
Commit 6da6b1d4a7df ("mm/hwpoison: convert TTU_IGNORE_HWPOISON to
TTU_HWPOISON") introduce TTU_HWPOISON to replace TTU_IGNORE_HWPOISON
in order to stop send SIGBUS signal when accessing an error page after
a memory error on a clean folio. However during page migration, anon
folio must be set with TTU_HWPOISON during unmap_*(). For pagecache
we need some policy just like the one in hwpoison_user_mappings to
set this flag. So move this policy from hwpoison_user_mappings to
unmap_poisoned_folio to handle this waring properly.
Waring will be produced during unamp poison folio with the following log:
------------[ cut here ]------------
WARNING: CPU: 1 PID: 365 at mm/rmap.c:1847 try_to_unmap_one+0x8fc/0xd3c
Modules linked in:
CPU: 1 UID: 0 PID: 365 Comm: bash Tainted: G W 6.13.0-rc1-00018-gacdb4bbda7ab #42
Tainted: [W]=WARN
Hardware name: QEMU QEMU Virtual Machine, BIOS 0.0.0 02/06/2015
pstate: 20400005 (nzCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
pc : try_to_unmap_one+0x8fc/0xd3c
lr : try_to_unmap_one+0x3dc/0xd3c
Call trace:
try_to_unmap_one+0x8fc/0xd3c (P)
try_to_unmap_one+0x3dc/0xd3c (L)
rmap_walk_anon+0xdc/0x1f8
rmap_walk+0x3c/0x58
try_to_unmap+0x88/0x90
unmap_poisoned_folio+0x30/0xa8
do_migrate_range+0x4a0/0x568
offline_pages+0x5a4/0x670
memory_block_action+0x17c/0x374
memory_subsys_offline+0x3c/0x78
device_offline+0xa4/0xd0
state_store+0x8c/0xf0
dev_attr_store+0x18/0x2c
sysfs_kf_write+0x44/0x54
kernfs_fop_write_iter+0x118/0x1a8
vfs_write+0x3a8/0x4bc
ksys_write+0x6c/0xf8
__arm64_sys_write+0x1c/0x28
invoke_syscall+0x44/0x100
el0_svc_common.constprop.0+0x40/0xe0
do_el0_svc+0x1c/0x28
el0_svc+0x30/0xd0
el0t_64_sync_handler+0xc8/0xcc
el0t_64_sync+0x198/0x19c
---[ end trace 0000000000000000 ]---
Fixes: 6da6b1d4a7df ("mm/hwpoison: convert TTU_IGNORE_HWPOISON to TTU_HWPOISON")
Signed-off-by: Ma Wupeng <mawupeng1@...wei.com>
Suggested-by: David Hildenbrand <david@...hat.com>
---
mm/internal.h | 5 ++--
mm/memory-failure.c | 61 +++++++++++++++++++++++----------------------
mm/memory_hotplug.c | 3 ++-
3 files changed, 36 insertions(+), 33 deletions(-)
diff --git a/mm/internal.h b/mm/internal.h
index 9826f7dce607..3caee67c0abd 100644
--- a/mm/internal.h
+++ b/mm/internal.h
@@ -1102,7 +1102,7 @@ static inline int find_next_best_node(int node, nodemask_t *used_node_mask)
* mm/memory-failure.c
*/
#ifdef CONFIG_MEMORY_FAILURE
-void unmap_poisoned_folio(struct folio *folio, enum ttu_flags ttu);
+int unmap_poisoned_folio(struct folio *folio, unsigned long pfn, bool must_kill);
void shake_folio(struct folio *folio);
extern int hwpoison_filter(struct page *p);
@@ -1125,8 +1125,9 @@ unsigned long page_mapped_in_vma(const struct page *page,
struct vm_area_struct *vma);
#else
-static inline void unmap_poisoned_folio(struct folio *folio, enum ttu_flags ttu)
+static inline int unmap_poisoned_folio(struct folio *folio, unsigned long pfn, bool must_kill);
{
+ return -EBUSY;
}
#endif
diff --git a/mm/memory-failure.c b/mm/memory-failure.c
index a7b8ccd29b6f..b5212b6e330a 100644
--- a/mm/memory-failure.c
+++ b/mm/memory-failure.c
@@ -1556,8 +1556,34 @@ static int get_hwpoison_page(struct page *p, unsigned long flags)
return ret;
}
-void unmap_poisoned_folio(struct folio *folio, enum ttu_flags ttu)
+int unmap_poisoned_folio(struct folio *folio, unsigned long pfn, bool must_kill)
{
+ enum ttu_flags ttu = TTU_IGNORE_MLOCK | TTU_SYNC | TTU_HWPOISON;
+ struct address_space *mapping;
+
+ if (folio_test_swapcache(folio)) {
+ pr_err("%#lx: keeping poisoned page in swap cache\n", pfn);
+ ttu &= ~TTU_HWPOISON;
+ }
+
+ /*
+ * Propagate the dirty bit from PTEs to struct page first, because we
+ * need this to decide if we should kill or just drop the page.
+ * XXX: the dirty test could be racy: set_page_dirty() may not always
+ * be called inside page lock (it's recommended but not enforced).
+ */
+ mapping = folio_mapping(folio);
+ if (!must_kill && !folio_test_dirty(folio) && mapping &&
+ mapping_can_writeback(mapping)) {
+ if (folio_mkclean(folio)) {
+ folio_set_dirty(folio);
+ } else {
+ ttu &= ~TTU_HWPOISON;
+ pr_info("%#lx: corrupted page was clean: dropped without side effects\n",
+ pfn);
+ }
+ }
+
if (folio_test_hugetlb(folio) && !folio_test_anon(folio)) {
struct address_space *mapping;
@@ -1572,7 +1598,7 @@ void unmap_poisoned_folio(struct folio *folio, enum ttu_flags ttu)
if (!mapping) {
pr_info("%#lx: could not lock mapping for mapped hugetlb folio\n",
folio_pfn(folio));
- return;
+ return -EBUSY;
}
try_to_unmap(folio, ttu|TTU_RMAP_LOCKED);
@@ -1580,6 +1606,8 @@ void unmap_poisoned_folio(struct folio *folio, enum ttu_flags ttu)
} else {
try_to_unmap(folio, ttu);
}
+
+ return folio_mapped(folio) ? -EBUSY : 0;
}
/*
@@ -1589,8 +1617,6 @@ void unmap_poisoned_folio(struct folio *folio, enum ttu_flags ttu)
static bool hwpoison_user_mappings(struct folio *folio, struct page *p,
unsigned long pfn, int flags)
{
- enum ttu_flags ttu = TTU_IGNORE_MLOCK | TTU_SYNC | TTU_HWPOISON;
- struct address_space *mapping;
LIST_HEAD(tokill);
bool unmap_success;
int forcekill;
@@ -1613,29 +1639,6 @@ static bool hwpoison_user_mappings(struct folio *folio, struct page *p,
if (!folio_mapped(folio))
return true;
- if (folio_test_swapcache(folio)) {
- pr_err("%#lx: keeping poisoned page in swap cache\n", pfn);
- ttu &= ~TTU_HWPOISON;
- }
-
- /*
- * Propagate the dirty bit from PTEs to struct page first, because we
- * need this to decide if we should kill or just drop the page.
- * XXX: the dirty test could be racy: set_page_dirty() may not always
- * be called inside page lock (it's recommended but not enforced).
- */
- mapping = folio_mapping(folio);
- if (!(flags & MF_MUST_KILL) && !folio_test_dirty(folio) && mapping &&
- mapping_can_writeback(mapping)) {
- if (folio_mkclean(folio)) {
- folio_set_dirty(folio);
- } else {
- ttu &= ~TTU_HWPOISON;
- pr_info("%#lx: corrupted page was clean: dropped without side effects\n",
- pfn);
- }
- }
-
/*
* First collect all the processes that have the page
* mapped in dirty form. This has to be done before try_to_unmap,
@@ -1643,9 +1646,7 @@ static bool hwpoison_user_mappings(struct folio *folio, struct page *p,
*/
collect_procs(folio, p, &tokill, flags & MF_ACTION_REQUIRED);
- unmap_poisoned_folio(folio, ttu);
-
- unmap_success = !folio_mapped(folio);
+ unmap_success = !unmap_poisoned_folio(folio, pfn, flags & MF_MUST_KILL);
if (!unmap_success)
pr_err("%#lx: failed to unmap page (folio mapcount=%d)\n",
pfn, folio_mapcount(folio));
diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
index c43b4e7fb298..3de661e57e92 100644
--- a/mm/memory_hotplug.c
+++ b/mm/memory_hotplug.c
@@ -1806,7 +1806,8 @@ static void do_migrate_range(unsigned long start_pfn, unsigned long end_pfn)
if (WARN_ON(folio_test_lru(folio)))
folio_isolate_lru(folio);
if (folio_mapped(folio))
- unmap_poisoned_folio(folio, TTU_IGNORE_MLOCK);
+ unmap_poisoned_folio(folio, pfn, false);
+
continue;
}
--
2.43.0
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