The quilt patch titled
Subject: ocfs2: handle a symlink read error correctly
has been removed from the -mm tree. Its filename was
ocfs2-handle-a-symlink-read-error-correctly.patch
This patch was dropped because it was merged into the mm-nonmm-stable branch
of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
------------------------------------------------------
From: "Matthew Wilcox (Oracle)" <willy(a)infradead.org>
Subject: ocfs2: handle a symlink read error correctly
Date: Thu, 5 Dec 2024 17:16:29 +0000
Patch series "Convert ocfs2 to use folios".
Mark did a conversion of ocfs2 to use folios and sent it to me as a
giant patch for review ;-)
So I've redone it as individual patches, and credited Mark for the patches
where his code is substantially the same. It's not a bad way to do it;
his patch had some bugs and my patches had some bugs. Hopefully all our
bugs were different from each other. And hopefully Mark likes all the
changes I made to his code!
This patch (of 23):
If we can't read the buffer, be sure to unlock the page before returning.
Link: https://lkml.kernel.org/r/20241205171653.3179945-1-willy@infradead.org
Link: https://lkml.kernel.org/r/20241205171653.3179945-2-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy(a)infradead.org>
Reviewed-by: Joseph Qi <joseph.qi(a)linux.alibaba.com>
Cc: Mark Fasheh <mark(a)fasheh.com>
Cc: Joel Becker <jlbec(a)evilplan.org>
Cc: Junxiao Bi <junxiao.bi(a)oracle.com>
Cc: Changwei Ge <gechangwei(a)live.cn>
Cc: Jun Piao <piaojun(a)huawei.com>
Cc: Mark Tinguely <mark.tinguely(a)oracle.com>
Cc: <stable(a)vger.kernel.org>
Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org>
---
fs/ocfs2/symlink.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
--- a/fs/ocfs2/symlink.c~ocfs2-handle-a-symlink-read-error-correctly
+++ a/fs/ocfs2/symlink.c
@@ -65,7 +65,7 @@ static int ocfs2_fast_symlink_read_folio
if (status < 0) {
mlog_errno(status);
- return status;
+ goto out;
}
fe = (struct ocfs2_dinode *) bh->b_data;
@@ -76,9 +76,10 @@ static int ocfs2_fast_symlink_read_folio
memcpy(kaddr, link, len + 1);
kunmap_atomic(kaddr);
SetPageUptodate(page);
+out:
unlock_page(page);
brelse(bh);
- return 0;
+ return status;
}
const struct address_space_operations ocfs2_fast_symlink_aops = {
_
Patches currently in -mm which might be from willy(a)infradead.org are
mm-page_alloc-cache-page_zone-result-in-free_unref_page.patch
mm-make-alloc_pages_mpol-static.patch
mm-page_alloc-export-free_frozen_pages-instead-of-free_unref_page.patch
mm-page_alloc-move-set_page_refcounted-to-callers-of-post_alloc_hook.patch
mm-page_alloc-move-set_page_refcounted-to-callers-of-prep_new_page.patch
mm-page_alloc-move-set_page_refcounted-to-callers-of-get_page_from_freelist.patch
mm-page_alloc-move-set_page_refcounted-to-callers-of-__alloc_pages_cpuset_fallback.patch
mm-page_alloc-move-set_page_refcounted-to-callers-of-__alloc_pages_may_oom.patch
mm-page_alloc-move-set_page_refcounted-to-callers-of-__alloc_pages_direct_compact.patch
mm-page_alloc-move-set_page_refcounted-to-callers-of-__alloc_pages_direct_reclaim.patch
mm-page_alloc-move-set_page_refcounted-to-callers-of-__alloc_pages_slowpath.patch
mm-page_alloc-move-set_page_refcounted-to-end-of-__alloc_pages.patch
mm-page_alloc-add-__alloc_frozen_pages.patch
mm-mempolicy-add-alloc_frozen_pages.patch
slab-allocate-frozen-pages.patch
mm-remove-pagetranstail.patch
The quilt patch titled
Subject: fs/proc: fix softlockup in __read_vmcore (part 2)
has been removed from the -mm tree. Its filename was
fs-proc-fix-softlockup-in-__read_vmcore-part-2.patch
This patch was dropped because it was merged into the mm-hotfixes-stable branch
of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
------------------------------------------------------
From: Rik van Riel <riel(a)surriel.com>
Subject: fs/proc: fix softlockup in __read_vmcore (part 2)
Date: Fri, 10 Jan 2025 10:28:21 -0500
Since commit 5cbcb62dddf5 ("fs/proc: fix softlockup in __read_vmcore") the
number of softlockups in __read_vmcore at kdump time have gone down, but
they still happen sometimes.
In a memory constrained environment like the kdump image, a softlockup is
not just a harmless message, but it can interfere with things like RCU
freeing memory, causing the crashdump to get stuck.
The second loop in __read_vmcore has a lot more opportunities for natural
sleep points, like scheduling out while waiting for a data write to
happen, but apparently that is not always enough.
Add a cond_resched() to the second loop in __read_vmcore to (hopefully)
get rid of the softlockups.
Link: https://lkml.kernel.org/r/20250110102821.2a37581b@fangorn
Fixes: 5cbcb62dddf5 ("fs/proc: fix softlockup in __read_vmcore")
Signed-off-by: Rik van Riel <riel(a)surriel.com>
Reported-by: Breno Leitao <leitao(a)debian.org>
Cc: Baoquan He <bhe(a)redhat.com>
Cc: Dave Young <dyoung(a)redhat.com>
Cc: Vivek Goyal <vgoyal(a)redhat.com>
Cc: <stable(a)vger.kernel.org>
Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org>
---
fs/proc/vmcore.c | 2 ++
1 file changed, 2 insertions(+)
--- a/fs/proc/vmcore.c~fs-proc-fix-softlockup-in-__read_vmcore-part-2
+++ a/fs/proc/vmcore.c
@@ -404,6 +404,8 @@ static ssize_t __read_vmcore(struct iov_
if (!iov_iter_count(iter))
return acc;
}
+
+ cond_resched();
}
return acc;
_
Patches currently in -mm which might be from riel(a)surriel.com are
mm-remove-unnecessary-calls-to-lru_add_drain.patch
The quilt patch titled
Subject: mm: vmscan : pgdemote vmstat is not getting updated when MGLRU is enabled.
has been removed from the -mm tree. Its filename was
mm-vmscan-pgdemote-vmstat-is-not-getting-updated-when-mglru-is-enabled.patch
This patch was dropped because it was merged into the mm-hotfixes-stable branch
of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
------------------------------------------------------
From: Donet Tom <donettom(a)linux.ibm.com>
Subject: mm: vmscan : pgdemote vmstat is not getting updated when MGLRU is enabled.
Date: Thu, 9 Jan 2025 00:05:39 -0600
When MGLRU is enabled, the pgdemote_kswapd, pgdemote_direct, and
pgdemote_khugepaged stats in vmstat are not being updated.
Commit f77f0c751478 ("mm,memcg: provide per-cgroup counters for NUMA
balancing operations") moved the pgdemote vmstat update from
demote_folio_list() to shrink_inactive_list(), which is in the normal LRU
path. As a result, the pgdemote stats are updated correctly for the
normal LRU but not for MGLRU.
To address this, we have added the pgdemote stat update in the
evict_folios() function, which is in the MGLRU path. With this patch, the
pgdemote stats will now be updated correctly when MGLRU is enabled.
Without this patch vmstat output when MGLRU is enabled
======================================================
pgdemote_kswapd 0
pgdemote_direct 0
pgdemote_khugepaged 0
With this patch vmstat output when MGLRU is enabled
===================================================
pgdemote_kswapd 43234
pgdemote_direct 4691
pgdemote_khugepaged 0
Link: https://lkml.kernel.org/r/20250109060540.451261-1-donettom@linux.ibm.com
Fixes: f77f0c751478 ("mm,memcg: provide per-cgroup counters for NUMA balancing operations")
Signed-off-by: Donet Tom <donettom(a)linux.ibm.com>
Acked-by: Yu Zhao <yuzhao(a)google.com>
Tested-by: Li Zhijian <lizhijian(a)fujitsu.com>
Reviewed-by: Li Zhijian <lizhijian(a)fujitsu.com>
Cc: Aneesh Kumar K.V (Arm) <aneesh.kumar(a)kernel.org>
Cc: David Rientjes <rientjes(a)google.com>
Cc: Johannes Weiner <hannes(a)cmpxchg.org>
Cc: Kaiyang Zhao <kaiyang2(a)cs.cmu.edu>
Cc: Michal Hocko <mhocko(a)kernel.org>
Cc: Muchun Song <muchun.song(a)linux.dev>
Cc: Ritesh Harjani (IBM) <ritesh.list(a)gmail.com>
Cc: Roman Gushchin <roman.gushchin(a)linux.dev>
Cc: Shakeel Butt <shakeel.butt(a)linux.dev>
Cc: Wei Xu <weixugc(a)google.com>
Cc: <stable(a)vger.kernel.org>
Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org>
---
mm/vmscan.c | 3 +++
1 file changed, 3 insertions(+)
--- a/mm/vmscan.c~mm-vmscan-pgdemote-vmstat-is-not-getting-updated-when-mglru-is-enabled
+++ a/mm/vmscan.c
@@ -4642,6 +4642,9 @@ retry:
reset_batch_size(walk);
}
+ __mod_lruvec_state(lruvec, PGDEMOTE_KSWAPD + reclaimer_offset(),
+ stat.nr_demoted);
+
item = PGSTEAL_KSWAPD + reclaimer_offset();
if (!cgroup_reclaim(sc))
__count_vm_events(item, reclaimed);
_
Patches currently in -mm which might be from donettom(a)linux.ibm.com are
mm-migrate-removed-unused-argument-vma-from-migrate_misplaced_folio.patch
selftests-mm-added-new-test-cases-to-the-migration-test.patch
The quilt patch titled
Subject: zram: fix potential UAF of zram table
has been removed from the -mm tree. Its filename was
zram-fix-potential-uaf-of-zram-table.patch
This patch was dropped because it was merged into the mm-hotfixes-stable branch
of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
------------------------------------------------------
From: Kairui Song <kasong(a)tencent.com>
Subject: zram: fix potential UAF of zram table
Date: Tue, 7 Jan 2025 14:54:46 +0800
If zram_meta_alloc failed early, it frees allocated zram->table without
setting it NULL. Which will potentially cause zram_meta_free to access
the table if user reset an failed and uninitialized device.
Link: https://lkml.kernel.org/r/20250107065446.86928-1-ryncsn@gmail.com
Fixes: 74363ec674cb ("zram: fix uninitialized ZRAM not releasing backing device")
Signed-off-by: Kairui Song <kasong(a)tencent.com>
Reviewed-by: Sergey Senozhatsky <senozhatsky(a)chromium.org>
Cc: <stable(a)vger.kernel.org>
Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org>
---
drivers/block/zram/zram_drv.c | 1 +
1 file changed, 1 insertion(+)
--- a/drivers/block/zram/zram_drv.c~zram-fix-potential-uaf-of-zram-table
+++ a/drivers/block/zram/zram_drv.c
@@ -1468,6 +1468,7 @@ static bool zram_meta_alloc(struct zram
zram->mem_pool = zs_create_pool(zram->disk->disk_name);
if (!zram->mem_pool) {
vfree(zram->table);
+ zram->table = NULL;
return false;
}
_
Patches currently in -mm which might be from kasong(a)tencent.com are
mm-memcontrol-avoid-duplicated-memcg-enable-check.patch
mm-swap_cgroup-remove-swap_cgroup_cmpxchg.patch
mm-swap_cgroup-remove-global-swap-cgroup-lock.patch
mm-swap_cgroup-decouple-swap-cgroup-recording-and-clearing.patch
mm-swap-minor-clean-up-for-swap-entry-allocation.patch
mm-swap-fold-swap_info_get_cont-in-the-only-caller.patch
mm-swap-remove-old-allocation-path-for-hdd.patch
mm-swap-use-cluster-lock-for-hdd.patch
mm-swap-clean-up-device-availability-check.patch
mm-swap-clean-up-plist-removal-and-adding.patch
mm-swap-hold-a-reference-during-scan-and-cleanup-flag-usage.patch
mm-swap-use-an-enum-to-define-all-cluster-flags-and-wrap-flags-changes.patch
mm-swap-reduce-contention-on-device-lock.patch
mm-swap-simplify-percpu-cluster-updating.patch
mm-swap-introduce-a-helper-for-retrieving-cluster-from-offset.patch
mm-swap-use-a-global-swap-cluster-for-non-rotation-devices.patch
mm-swap_slots-remove-slot-cache-for-freeing-path.patch
The quilt patch titled
Subject: selftests/mm: set allocated memory to non-zero content in cow test
has been removed from the -mm tree. Its filename was
selftests-mm-set-allocated-memory-to-non-zero-content-in-cow-test.patch
This patch was dropped because it was merged into the mm-hotfixes-stable branch
of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
------------------------------------------------------
From: Ryan Roberts <ryan.roberts(a)arm.com>
Subject: selftests/mm: set allocated memory to non-zero content in cow test
Date: Tue, 7 Jan 2025 14:25:53 +0000
After commit b1f202060afe ("mm: remap unused subpages to shared zeropage
when splitting isolated thp"), cow test cases involving swapping out THPs
via madvise(MADV_PAGEOUT) started to be skipped due to the subsequent
check via pagemap determining that the memory was not actually swapped
out. Logs similar to this were emitted:
...
# [RUN] Basic COW after fork() ... with swapped-out, PTE-mapped THP (16 kB)
ok 2 # SKIP MADV_PAGEOUT did not work, is swap enabled?
# [RUN] Basic COW after fork() ... with single PTE of swapped-out THP (16 kB)
ok 3 # SKIP MADV_PAGEOUT did not work, is swap enabled?
# [RUN] Basic COW after fork() ... with swapped-out, PTE-mapped THP (32 kB)
ok 4 # SKIP MADV_PAGEOUT did not work, is swap enabled?
...
The commit in question introduces the behaviour of scanning THPs and if
their content is predominantly zero, it splits them and replaces the pages
which are wholly zero with the zero page. These cow test cases were
getting caught up in this.
So let's avoid that by filling the contents of all allocated memory with
a non-zero value. With this in place, the tests are passing again.
Link: https://lkml.kernel.org/r/20250107142555.1870101-1-ryan.roberts@arm.com
Fixes: b1f202060afe ("mm: remap unused subpages to shared zeropage when splitting isolated thp")
Signed-off-by: Ryan Roberts <ryan.roberts(a)arm.com>
Acked-by: David Hildenbrand <david(a)redhat.com>
Cc: Usama Arif <usamaarif642(a)gmail.com>
Cc: Yu Zhao <yuzhao(a)google.com>
Cc: <stable(a)vger.kernel.org>
Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org>
---
tools/testing/selftests/mm/cow.c | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)
--- a/tools/testing/selftests/mm/cow.c~selftests-mm-set-allocated-memory-to-non-zero-content-in-cow-test
+++ a/tools/testing/selftests/mm/cow.c
@@ -758,7 +758,7 @@ static void do_run_with_base_page(test_f
}
/* Populate a base page. */
- memset(mem, 0, pagesize);
+ memset(mem, 1, pagesize);
if (swapout) {
madvise(mem, pagesize, MADV_PAGEOUT);
@@ -824,12 +824,12 @@ static void do_run_with_thp(test_fn fn,
* Try to populate a THP. Touch the first sub-page and test if
* we get the last sub-page populated automatically.
*/
- mem[0] = 0;
+ mem[0] = 1;
if (!pagemap_is_populated(pagemap_fd, mem + thpsize - pagesize)) {
ksft_test_result_skip("Did not get a THP populated\n");
goto munmap;
}
- memset(mem, 0, thpsize);
+ memset(mem, 1, thpsize);
size = thpsize;
switch (thp_run) {
@@ -1012,7 +1012,7 @@ static void run_with_hugetlb(test_fn fn,
}
/* Populate an huge page. */
- memset(mem, 0, hugetlbsize);
+ memset(mem, 1, hugetlbsize);
/*
* We need a total of two hugetlb pages to handle COW/unsharing
_
Patches currently in -mm which might be from ryan.roberts(a)arm.com are
selftests-mm-add-fork-cow-guard-page-test-fix.patch
selftests-mm-introduce-uffd-wp-mremap-regression-test.patch
The quilt patch titled
Subject: mm: clear uffd-wp PTE/PMD state on mremap()
has been removed from the -mm tree. Its filename was
mm-clear-uffd-wp-pte-pmd-state-on-mremap.patch
This patch was dropped because it was merged into the mm-hotfixes-stable branch
of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
------------------------------------------------------
From: Ryan Roberts <ryan.roberts(a)arm.com>
Subject: mm: clear uffd-wp PTE/PMD state on mremap()
Date: Tue, 7 Jan 2025 14:47:52 +0000
When mremap()ing a memory region previously registered with userfaultfd as
write-protected but without UFFD_FEATURE_EVENT_REMAP, an inconsistency in
flag clearing leads to a mismatch between the vma flags (which have
uffd-wp cleared) and the pte/pmd flags (which do not have uffd-wp
cleared). This mismatch causes a subsequent mprotect(PROT_WRITE) to
trigger a warning in page_table_check_pte_flags() due to setting the pte
to writable while uffd-wp is still set.
Fix this by always explicitly clearing the uffd-wp pte/pmd flags on any
such mremap() so that the values are consistent with the existing clearing
of VM_UFFD_WP. Be careful to clear the logical flag regardless of its
physical form; a PTE bit, a swap PTE bit, or a PTE marker. Cover PTE,
huge PMD and hugetlb paths.
Link: https://lkml.kernel.org/r/20250107144755.1871363-2-ryan.roberts@arm.com
Co-developed-by: Miko��aj Lenczewski <miko.lenczewski(a)arm.com>
Signed-off-by: Miko��aj Lenczewski <miko.lenczewski(a)arm.com>
Signed-off-by: Ryan Roberts <ryan.roberts(a)arm.com>
Closes: https://lore.kernel.org/linux-mm/810b44a8-d2ae-4107-b665-5a42eae2d948@arm.c…
Fixes: 63b2d4174c4a ("userfaultfd: wp: add the writeprotect API to userfaultfd ioctl")
Cc: David Hildenbrand <david(a)redhat.com>
Cc: Jann Horn <jannh(a)google.com>
Cc: Liam R. Howlett <Liam.Howlett(a)Oracle.com>
Cc: Lorenzo Stoakes <lorenzo.stoakes(a)oracle.com>
Cc: Mark Rutland <mark.rutland(a)arm.com>
Cc: Muchun Song <muchun.song(a)linux.dev>
Cc: Peter Xu <peterx(a)redhat.com>
Cc: Shuah Khan <shuah(a)kernel.org>
Cc: Vlastimil Babka <vbabka(a)suse.cz>
Cc: <stable(a)vger.kernel.org>
Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org>
---
include/linux/userfaultfd_k.h | 12 ++++++++++++
mm/huge_memory.c | 12 ++++++++++++
mm/hugetlb.c | 14 +++++++++++++-
mm/mremap.c | 32 +++++++++++++++++++++++++++++++-
4 files changed, 68 insertions(+), 2 deletions(-)
--- a/include/linux/userfaultfd_k.h~mm-clear-uffd-wp-pte-pmd-state-on-mremap
+++ a/include/linux/userfaultfd_k.h
@@ -247,6 +247,13 @@ static inline bool vma_can_userfault(str
vma_is_shmem(vma);
}
+static inline bool vma_has_uffd_without_event_remap(struct vm_area_struct *vma)
+{
+ struct userfaultfd_ctx *uffd_ctx = vma->vm_userfaultfd_ctx.ctx;
+
+ return uffd_ctx && (uffd_ctx->features & UFFD_FEATURE_EVENT_REMAP) == 0;
+}
+
extern int dup_userfaultfd(struct vm_area_struct *, struct list_head *);
extern void dup_userfaultfd_complete(struct list_head *);
void dup_userfaultfd_fail(struct list_head *);
@@ -401,6 +408,11 @@ static inline bool userfaultfd_wp_async(
{
return false;
}
+
+static inline bool vma_has_uffd_without_event_remap(struct vm_area_struct *vma)
+{
+ return false;
+}
#endif /* CONFIG_USERFAULTFD */
--- a/mm/huge_memory.c~mm-clear-uffd-wp-pte-pmd-state-on-mremap
+++ a/mm/huge_memory.c
@@ -2206,6 +2206,16 @@ static pmd_t move_soft_dirty_pmd(pmd_t p
return pmd;
}
+static pmd_t clear_uffd_wp_pmd(pmd_t pmd)
+{
+ if (pmd_present(pmd))
+ pmd = pmd_clear_uffd_wp(pmd);
+ else if (is_swap_pmd(pmd))
+ pmd = pmd_swp_clear_uffd_wp(pmd);
+
+ return pmd;
+}
+
bool move_huge_pmd(struct vm_area_struct *vma, unsigned long old_addr,
unsigned long new_addr, pmd_t *old_pmd, pmd_t *new_pmd)
{
@@ -2244,6 +2254,8 @@ bool move_huge_pmd(struct vm_area_struct
pgtable_trans_huge_deposit(mm, new_pmd, pgtable);
}
pmd = move_soft_dirty_pmd(pmd);
+ if (vma_has_uffd_without_event_remap(vma))
+ pmd = clear_uffd_wp_pmd(pmd);
set_pmd_at(mm, new_addr, new_pmd, pmd);
if (force_flush)
flush_pmd_tlb_range(vma, old_addr, old_addr + PMD_SIZE);
--- a/mm/hugetlb.c~mm-clear-uffd-wp-pte-pmd-state-on-mremap
+++ a/mm/hugetlb.c
@@ -5402,6 +5402,7 @@ static void move_huge_pte(struct vm_area
unsigned long new_addr, pte_t *src_pte, pte_t *dst_pte,
unsigned long sz)
{
+ bool need_clear_uffd_wp = vma_has_uffd_without_event_remap(vma);
struct hstate *h = hstate_vma(vma);
struct mm_struct *mm = vma->vm_mm;
spinlock_t *src_ptl, *dst_ptl;
@@ -5418,7 +5419,18 @@ static void move_huge_pte(struct vm_area
spin_lock_nested(src_ptl, SINGLE_DEPTH_NESTING);
pte = huge_ptep_get_and_clear(mm, old_addr, src_pte);
- set_huge_pte_at(mm, new_addr, dst_pte, pte, sz);
+
+ if (need_clear_uffd_wp && pte_marker_uffd_wp(pte))
+ huge_pte_clear(mm, new_addr, dst_pte, sz);
+ else {
+ if (need_clear_uffd_wp) {
+ if (pte_present(pte))
+ pte = huge_pte_clear_uffd_wp(pte);
+ else if (is_swap_pte(pte))
+ pte = pte_swp_clear_uffd_wp(pte);
+ }
+ set_huge_pte_at(mm, new_addr, dst_pte, pte, sz);
+ }
if (src_ptl != dst_ptl)
spin_unlock(src_ptl);
--- a/mm/mremap.c~mm-clear-uffd-wp-pte-pmd-state-on-mremap
+++ a/mm/mremap.c
@@ -138,6 +138,7 @@ static int move_ptes(struct vm_area_stru
struct vm_area_struct *new_vma, pmd_t *new_pmd,
unsigned long new_addr, bool need_rmap_locks)
{
+ bool need_clear_uffd_wp = vma_has_uffd_without_event_remap(vma);
struct mm_struct *mm = vma->vm_mm;
pte_t *old_pte, *new_pte, pte;
pmd_t dummy_pmdval;
@@ -216,7 +217,18 @@ static int move_ptes(struct vm_area_stru
force_flush = true;
pte = move_pte(pte, old_addr, new_addr);
pte = move_soft_dirty_pte(pte);
- set_pte_at(mm, new_addr, new_pte, pte);
+
+ if (need_clear_uffd_wp && pte_marker_uffd_wp(pte))
+ pte_clear(mm, new_addr, new_pte);
+ else {
+ if (need_clear_uffd_wp) {
+ if (pte_present(pte))
+ pte = pte_clear_uffd_wp(pte);
+ else if (is_swap_pte(pte))
+ pte = pte_swp_clear_uffd_wp(pte);
+ }
+ set_pte_at(mm, new_addr, new_pte, pte);
+ }
}
arch_leave_lazy_mmu_mode();
@@ -278,6 +290,15 @@ static bool move_normal_pmd(struct vm_ar
if (WARN_ON_ONCE(!pmd_none(*new_pmd)))
return false;
+ /* If this pmd belongs to a uffd vma with remap events disabled, we need
+ * to ensure that the uffd-wp state is cleared from all pgtables. This
+ * means recursing into lower page tables in move_page_tables(), and we
+ * can reuse the existing code if we simply treat the entry as "not
+ * moved".
+ */
+ if (vma_has_uffd_without_event_remap(vma))
+ return false;
+
/*
* We don't have to worry about the ordering of src and dst
* ptlocks because exclusive mmap_lock prevents deadlock.
@@ -333,6 +354,15 @@ static bool move_normal_pud(struct vm_ar
if (WARN_ON_ONCE(!pud_none(*new_pud)))
return false;
+ /* If this pud belongs to a uffd vma with remap events disabled, we need
+ * to ensure that the uffd-wp state is cleared from all pgtables. This
+ * means recursing into lower page tables in move_page_tables(), and we
+ * can reuse the existing code if we simply treat the entry as "not
+ * moved".
+ */
+ if (vma_has_uffd_without_event_remap(vma))
+ return false;
+
/*
* We don't have to worry about the ordering of src and dst
* ptlocks because exclusive mmap_lock prevents deadlock.
_
Patches currently in -mm which might be from ryan.roberts(a)arm.com are
selftests-mm-add-fork-cow-guard-page-test-fix.patch
selftests-mm-introduce-uffd-wp-mremap-regression-test.patch
The quilt patch titled
Subject: mm: zswap: properly synchronize freeing resources during CPU hotunplug
has been removed from the -mm tree. Its filename was
mm-zswap-properly-synchronize-freeing-resources-during-cpu-hotunplug.patch
This patch was dropped because it was merged into the mm-hotfixes-stable branch
of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
------------------------------------------------------
From: Yosry Ahmed <yosryahmed(a)google.com>
Subject: mm: zswap: properly synchronize freeing resources during CPU hotunplug
Date: Wed, 8 Jan 2025 22:24:41 +0000
In zswap_compress() and zswap_decompress(), the per-CPU acomp_ctx of the
current CPU at the beginning of the operation is retrieved and used
throughout. However, since neither preemption nor migration are disabled,
it is possible that the operation continues on a different CPU.
If the original CPU is hotunplugged while the acomp_ctx is still in use,
we run into a UAF bug as some of the resources attached to the acomp_ctx
are freed during hotunplug in zswap_cpu_comp_dead() (i.e.
acomp_ctx.buffer, acomp_ctx.req, or acomp_ctx.acomp).
The problem was introduced in commit 1ec3b5fe6eec ("mm/zswap: move to use
crypto_acomp API for hardware acceleration") when the switch to the
crypto_acomp API was made. Prior to that, the per-CPU crypto_comp was
retrieved using get_cpu_ptr() which disables preemption and makes sure the
CPU cannot go away from under us. Preemption cannot be disabled with the
crypto_acomp API as a sleepable context is needed.
Use the acomp_ctx.mutex to synchronize CPU hotplug callbacks allocating
and freeing resources with compression/decompression paths. Make sure
that acomp_ctx.req is NULL when the resources are freed. In the
compression/decompression paths, check if acomp_ctx.req is NULL after
acquiring the mutex (meaning the CPU was offlined) and retry on the new
CPU.
The initialization of acomp_ctx.mutex is moved from the CPU hotplug
callback to the pool initialization where it belongs (where the mutex is
allocated). In addition to adding clarity, this makes sure that CPU
hotplug cannot reinitialize a mutex that is already locked by
compression/decompression.
Previously a fix was attempted by holding cpus_read_lock() [1]. This
would have caused a potential deadlock as it is possible for code already
holding the lock to fall into reclaim and enter zswap (causing a
deadlock). A fix was also attempted using SRCU for synchronization, but
Johannes pointed out that synchronize_srcu() cannot be used in CPU hotplug
notifiers [2].
Alternative fixes that were considered/attempted and could have worked:
- Refcounting the per-CPU acomp_ctx. This involves complexity in
handling the race between the refcount dropping to zero in
zswap_[de]compress() and the refcount being re-initialized when the
CPU is onlined.
- Disabling migration before getting the per-CPU acomp_ctx [3], but
that's discouraged and is a much bigger hammer than needed, and could
result in subtle performance issues.
[1]https://lkml.kernel.org/20241219212437.2714151-1-yosryahmed@google.com/
[2]https://lkml.kernel.org/20250107074724.1756696-2-yosryahmed@google.com/
[3]https://lkml.kernel.org/20250107222236.2715883-2-yosryahmed@google.com/
[yosryahmed(a)google.com: remove comment]
Link: https://lkml.kernel.org/r/CAJD7tkaxS1wjn+swugt8QCvQ-rVF5RZnjxwPGX17k8x9zSMa…
Link: https://lkml.kernel.org/r/20250108222441.3622031-1-yosryahmed@google.com
Fixes: 1ec3b5fe6eec ("mm/zswap: move to use crypto_acomp API for hardware acceleration")
Signed-off-by: Yosry Ahmed <yosryahmed(a)google.com>
Reported-by: Johannes Weiner <hannes(a)cmpxchg.org>
Closes: https://lore.kernel.org/lkml/20241113213007.GB1564047@cmpxchg.org/
Reported-by: Sam Sun <samsun1006219(a)gmail.com>
Closes: https://lore.kernel.org/lkml/CAEkJfYMtSdM5HceNsXUDf5haghD5+o2e7Qv4OcuruL4tP…
Cc: Barry Song <baohua(a)kernel.org>
Cc: Chengming Zhou <chengming.zhou(a)linux.dev>
Cc: Kanchana P Sridhar <kanchana.p.sridhar(a)intel.com>
Cc: Nhat Pham <nphamcs(a)gmail.com>
Cc: Vitaly Wool <vitalywool(a)gmail.com>
Cc: <stable(a)vger.kernel.org>
Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org>
---
mm/zswap.c | 58 ++++++++++++++++++++++++++++++++++++++-------------
1 file changed, 44 insertions(+), 14 deletions(-)
--- a/mm/zswap.c~mm-zswap-properly-synchronize-freeing-resources-during-cpu-hotunplug
+++ a/mm/zswap.c
@@ -251,7 +251,7 @@ static struct zswap_pool *zswap_pool_cre
struct zswap_pool *pool;
char name[38]; /* 'zswap' + 32 char (max) num + \0 */
gfp_t gfp = __GFP_NORETRY | __GFP_NOWARN | __GFP_KSWAPD_RECLAIM;
- int ret;
+ int ret, cpu;
if (!zswap_has_pool) {
/* if either are unset, pool initialization failed, and we
@@ -285,6 +285,9 @@ static struct zswap_pool *zswap_pool_cre
goto error;
}
+ for_each_possible_cpu(cpu)
+ mutex_init(&per_cpu_ptr(pool->acomp_ctx, cpu)->mutex);
+
ret = cpuhp_state_add_instance(CPUHP_MM_ZSWP_POOL_PREPARE,
&pool->node);
if (ret)
@@ -821,11 +824,12 @@ static int zswap_cpu_comp_prepare(unsign
struct acomp_req *req;
int ret;
- mutex_init(&acomp_ctx->mutex);
-
+ mutex_lock(&acomp_ctx->mutex);
acomp_ctx->buffer = kmalloc_node(PAGE_SIZE * 2, GFP_KERNEL, cpu_to_node(cpu));
- if (!acomp_ctx->buffer)
- return -ENOMEM;
+ if (!acomp_ctx->buffer) {
+ ret = -ENOMEM;
+ goto buffer_fail;
+ }
acomp = crypto_alloc_acomp_node(pool->tfm_name, 0, 0, cpu_to_node(cpu));
if (IS_ERR(acomp)) {
@@ -855,12 +859,15 @@ static int zswap_cpu_comp_prepare(unsign
acomp_request_set_callback(req, CRYPTO_TFM_REQ_MAY_BACKLOG,
crypto_req_done, &acomp_ctx->wait);
+ mutex_unlock(&acomp_ctx->mutex);
return 0;
req_fail:
crypto_free_acomp(acomp_ctx->acomp);
acomp_fail:
kfree(acomp_ctx->buffer);
+buffer_fail:
+ mutex_unlock(&acomp_ctx->mutex);
return ret;
}
@@ -869,17 +876,45 @@ static int zswap_cpu_comp_dead(unsigned
struct zswap_pool *pool = hlist_entry(node, struct zswap_pool, node);
struct crypto_acomp_ctx *acomp_ctx = per_cpu_ptr(pool->acomp_ctx, cpu);
+ mutex_lock(&acomp_ctx->mutex);
if (!IS_ERR_OR_NULL(acomp_ctx)) {
if (!IS_ERR_OR_NULL(acomp_ctx->req))
acomp_request_free(acomp_ctx->req);
+ acomp_ctx->req = NULL;
if (!IS_ERR_OR_NULL(acomp_ctx->acomp))
crypto_free_acomp(acomp_ctx->acomp);
kfree(acomp_ctx->buffer);
}
+ mutex_unlock(&acomp_ctx->mutex);
return 0;
}
+static struct crypto_acomp_ctx *acomp_ctx_get_cpu_lock(struct zswap_pool *pool)
+{
+ struct crypto_acomp_ctx *acomp_ctx;
+
+ for (;;) {
+ acomp_ctx = raw_cpu_ptr(pool->acomp_ctx);
+ mutex_lock(&acomp_ctx->mutex);
+ if (likely(acomp_ctx->req))
+ return acomp_ctx;
+ /*
+ * It is possible that we were migrated to a different CPU after
+ * getting the per-CPU ctx but before the mutex was acquired. If
+ * the old CPU got offlined, zswap_cpu_comp_dead() could have
+ * already freed ctx->req (among other things) and set it to
+ * NULL. Just try again on the new CPU that we ended up on.
+ */
+ mutex_unlock(&acomp_ctx->mutex);
+ }
+}
+
+static void acomp_ctx_put_unlock(struct crypto_acomp_ctx *acomp_ctx)
+{
+ mutex_unlock(&acomp_ctx->mutex);
+}
+
static bool zswap_compress(struct page *page, struct zswap_entry *entry,
struct zswap_pool *pool)
{
@@ -893,10 +928,7 @@ static bool zswap_compress(struct page *
gfp_t gfp;
u8 *dst;
- acomp_ctx = raw_cpu_ptr(pool->acomp_ctx);
-
- mutex_lock(&acomp_ctx->mutex);
-
+ acomp_ctx = acomp_ctx_get_cpu_lock(pool);
dst = acomp_ctx->buffer;
sg_init_table(&input, 1);
sg_set_page(&input, page, PAGE_SIZE, 0);
@@ -949,7 +981,7 @@ unlock:
else if (alloc_ret)
zswap_reject_alloc_fail++;
- mutex_unlock(&acomp_ctx->mutex);
+ acomp_ctx_put_unlock(acomp_ctx);
return comp_ret == 0 && alloc_ret == 0;
}
@@ -960,9 +992,7 @@ static void zswap_decompress(struct zswa
struct crypto_acomp_ctx *acomp_ctx;
u8 *src;
- acomp_ctx = raw_cpu_ptr(entry->pool->acomp_ctx);
- mutex_lock(&acomp_ctx->mutex);
-
+ acomp_ctx = acomp_ctx_get_cpu_lock(entry->pool);
src = zpool_map_handle(zpool, entry->handle, ZPOOL_MM_RO);
/*
* If zpool_map_handle is atomic, we cannot reliably utilize its mapped buffer
@@ -986,10 +1016,10 @@ static void zswap_decompress(struct zswa
acomp_request_set_params(acomp_ctx->req, &input, &output, entry->length, PAGE_SIZE);
BUG_ON(crypto_wait_req(crypto_acomp_decompress(acomp_ctx->req), &acomp_ctx->wait));
BUG_ON(acomp_ctx->req->dlen != PAGE_SIZE);
- mutex_unlock(&acomp_ctx->mutex);
if (src != acomp_ctx->buffer)
zpool_unmap_handle(zpool, entry->handle);
+ acomp_ctx_put_unlock(acomp_ctx);
}
/*********************************
_
Patches currently in -mm which might be from yosryahmed(a)google.com are
The quilt patch titled
Subject: hugetlb: fix NULL pointer dereference in trace_hugetlbfs_alloc_inode
has been removed from the -mm tree. Its filename was
hugetlb-fix-null-pointer-dereference-in-trace_hugetlbfs_alloc_inode.patch
This patch was dropped because it was merged into the mm-hotfixes-stable branch
of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
------------------------------------------------------
From: Muchun Song <songmuchun(a)bytedance.com>
Subject: hugetlb: fix NULL pointer dereference in trace_hugetlbfs_alloc_inode
Date: Mon, 6 Jan 2025 11:31:17 +0800
hugetlb_file_setup() will pass a NULL @dir to hugetlbfs_get_inode(), so we
will access a NULL pointer for @dir. Fix it and set __entry->dr to 0 if
@dir is NULL. Because ->i_ino cannot be 0 (see get_next_ino()), there is
no confusing if user sees a 0 inode number.
Link: https://lkml.kernel.org/r/20250106033118.4640-1-songmuchun@bytedance.com
Fixes: 318580ad7f28 ("hugetlbfs: support tracepoint")
Signed-off-by: Muchun Song <songmuchun(a)bytedance.com>
Reported-by: Cheung Wall <zzqq0103.hey(a)gmail.com>
Closes: https://lore.kernel.org/linux-mm/02858D60-43C1-4863-A84F-3C76A8AF1F15@linux…
Reviewed-by: Hongbo Li <lihongbo22(a)huawei.com>
Cc: cheung wall <zzqq0103.hey(a)gmail.com>
Cc: Christian Brauner <brauner(a)kernel.org>
Cc: <stable(a)vger.kernel.org>
Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org>
---
include/trace/events/hugetlbfs.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
--- a/include/trace/events/hugetlbfs.h~hugetlb-fix-null-pointer-dereference-in-trace_hugetlbfs_alloc_inode
+++ a/include/trace/events/hugetlbfs.h
@@ -23,7 +23,7 @@ TRACE_EVENT(hugetlbfs_alloc_inode,
TP_fast_assign(
__entry->dev = inode->i_sb->s_dev;
__entry->ino = inode->i_ino;
- __entry->dir = dir->i_ino;
+ __entry->dir = dir ? dir->i_ino : 0;
__entry->mode = mode;
),
_
Patches currently in -mm which might be from songmuchun(a)bytedance.com are
The quilt patch titled
Subject: filemap: avoid truncating 64-bit offset to 32 bits
has been removed from the -mm tree. Its filename was
filemap-avoid-truncating-64-bit-offset-to-32-bits.patch
This patch was dropped because it was merged into the mm-hotfixes-stable branch
of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
------------------------------------------------------
From: Marco Nelissen <marco.nelissen(a)gmail.com>
Subject: filemap: avoid truncating 64-bit offset to 32 bits
Date: Thu, 2 Jan 2025 11:04:11 -0800
On 32-bit kernels, folio_seek_hole_data() was inadvertently truncating a
64-bit value to 32 bits, leading to a possible infinite loop when writing
to an xfs filesystem.
Link: https://lkml.kernel.org/r/20250102190540.1356838-1-marco.nelissen@gmail.com
Fixes: 54fa39ac2e00 ("iomap: use mapping_seek_hole_data")
Signed-off-by: Marco Nelissen <marco.nelissen(a)gmail.com>
Cc: Matthew Wilcox (Oracle) <willy(a)infradead.org>
Cc: <stable(a)vger.kernel.org>
Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org>
---
mm/filemap.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
--- a/mm/filemap.c~filemap-avoid-truncating-64-bit-offset-to-32-bits
+++ a/mm/filemap.c
@@ -2996,7 +2996,7 @@ static inline loff_t folio_seek_hole_dat
if (ops->is_partially_uptodate(folio, offset, bsz) ==
seek_data)
break;
- start = (start + bsz) & ~(bsz - 1);
+ start = (start + bsz) & ~((u64)bsz - 1);
offset += bsz;
} while (offset < folio_size(folio));
unlock:
_
Patches currently in -mm which might be from marco.nelissen(a)gmail.com are