The patch titled
Subject: fs/writeback: skip AS_NO_DATA_INTEGRITY mappings in wait_sb_inodes()
has been added to the -mm mm-hotfixes-unstable branch. Its filename is
fs-writeback-skip-as_no_data_integrity-mappings-in-wait_sb_inodes.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patche…
This patch will later appear in the mm-hotfixes-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Before you just go and hit "reply", please:
a) Consider who else should be cc'ed
b) Prefer to cc a suitable mailing list as well
c) Ideally: find the original patch on the mailing list and do a
reply-to-all to that, adding suitable additional cc's
*** Remember to use Documentation/process/submit-checklist.rst when testing your code ***
The -mm tree is included into linux-next via various
branches at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
and is updated there most days
------------------------------------------------------
From: Joanne Koong <joannelkoong(a)gmail.com>
Subject: fs/writeback: skip AS_NO_DATA_INTEGRITY mappings in wait_sb_inodes()
Date: Sun, 14 Dec 2025 19:00:43 -0800
Skip waiting on writeback for inodes that belong to mappings that do not
have data integrity guarantees (denoted by the AS_NO_DATA_INTEGRITY
mapping flag).
This restores fuse back to prior behavior where syncs are no-ops. This is
needed because otherwise, if a system is running a faulty fuse server that
does not reply to issued write requests, this will cause wait_sb_inodes()
to wait forever.
Link: https://lkml.kernel.org/r/20251215030043.1431306-2-joannelkoong@gmail.com
Fixes: 0c58a97f919c ("fuse: remove tmp folio for writebacks and internal rb tree")
Signed-off-by: Joanne Koong <joannelkoong(a)gmail.com>
Reported-by: Athul Krishna <athul.krishna.kr(a)protonmail.com>
Reported-by: J. Neusch��fer <j.neuschaefer(a)gmx.net>
Cc: Bonaccorso Salvatore <carnil(a)debian.org>
Cc: Jonathan Neuschaefer <j.neuschaefer(a)gmx.net>
Cc: Miklos Szeredi <miklos(a)szeredi.hu>
Cc: Alexander Viro <viro(a)zeniv.linux.org.uk>
Cc: Christian Brauner <brauner(a)kernel.org>
Cc: Jan Kara <jack(a)suse.cz>
Cc: "Matthew Wilcox (Oracle)" <willy(a)infradead.org>
Cc: David Hildenbrand <david(a)kernel.org>
Cc: Lorenzo Stoakes <lorenzo.stoakes(a)oracle.com>
Cc: "Liam R. Howlett" <Liam.Howlett(a)oracle.com>
Cc: Vlastimil Babka <vbabka(a)suse.cz>
Cc: Mike Rapoport <rppt(a)kernel.org>
Cc: Suren Baghdasaryan <surenb(a)google.com>
Cc: Michal Hocko <mhocko(a)suse.com>
Cc: <stable(a)vger.kernel.org>
Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org>
---
fs/fs-writeback.c | 3 ++-
fs/fuse/file.c | 4 +++-
include/linux/pagemap.h | 11 +++++++++++
3 files changed, 16 insertions(+), 2 deletions(-)
--- a/fs/fs-writeback.c~fs-writeback-skip-as_no_data_integrity-mappings-in-wait_sb_inodes
+++ a/fs/fs-writeback.c
@@ -2751,7 +2751,8 @@ static void wait_sb_inodes(struct super_
* do not have the mapping lock. Skip it here, wb completion
* will remove it.
*/
- if (!mapping_tagged(mapping, PAGECACHE_TAG_WRITEBACK))
+ if (!mapping_tagged(mapping, PAGECACHE_TAG_WRITEBACK) ||
+ mapping_no_data_integrity(mapping))
continue;
spin_unlock_irq(&sb->s_inode_wblist_lock);
--- a/fs/fuse/file.c~fs-writeback-skip-as_no_data_integrity-mappings-in-wait_sb_inodes
+++ a/fs/fuse/file.c
@@ -3200,8 +3200,10 @@ void fuse_init_file_inode(struct inode *
inode->i_fop = &fuse_file_operations;
inode->i_data.a_ops = &fuse_file_aops;
- if (fc->writeback_cache)
+ if (fc->writeback_cache) {
mapping_set_writeback_may_deadlock_on_reclaim(&inode->i_data);
+ mapping_set_no_data_integrity(&inode->i_data);
+ }
INIT_LIST_HEAD(&fi->write_files);
INIT_LIST_HEAD(&fi->queued_writes);
--- a/include/linux/pagemap.h~fs-writeback-skip-as_no_data_integrity-mappings-in-wait_sb_inodes
+++ a/include/linux/pagemap.h
@@ -210,6 +210,7 @@ enum mapping_flags {
AS_WRITEBACK_MAY_DEADLOCK_ON_RECLAIM = 9,
AS_KERNEL_FILE = 10, /* mapping for a fake kernel file that shouldn't
account usage to user cgroups */
+ AS_NO_DATA_INTEGRITY = 11, /* no data integrity guarantees */
/* Bits 16-25 are used for FOLIO_ORDER */
AS_FOLIO_ORDER_BITS = 5,
AS_FOLIO_ORDER_MIN = 16,
@@ -345,6 +346,16 @@ static inline bool mapping_writeback_may
return test_bit(AS_WRITEBACK_MAY_DEADLOCK_ON_RECLAIM, &mapping->flags);
}
+static inline void mapping_set_no_data_integrity(struct address_space *mapping)
+{
+ set_bit(AS_NO_DATA_INTEGRITY, &mapping->flags);
+}
+
+static inline bool mapping_no_data_integrity(const struct address_space *mapping)
+{
+ return test_bit(AS_NO_DATA_INTEGRITY, &mapping->flags);
+}
+
static inline gfp_t mapping_gfp_mask(const struct address_space *mapping)
{
return mapping->gfp_mask;
_
Patches currently in -mm which might be from joannelkoong(a)gmail.com are
fs-writeback-skip-as_no_data_integrity-mappings-in-wait_sb_inodes.patch
The patch titled
Subject: arm64: kernel: initialize missing kexec_buf->random field
has been added to the -mm mm-hotfixes-unstable branch. Its filename is
arm64-kernel-initialize-missing-kexec_buf-random-field.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patche…
This patch will later appear in the mm-hotfixes-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Before you just go and hit "reply", please:
a) Consider who else should be cc'ed
b) Prefer to cc a suitable mailing list as well
c) Ideally: find the original patch on the mailing list and do a
reply-to-all to that, adding suitable additional cc's
*** Remember to use Documentation/process/submit-checklist.rst when testing your code ***
The -mm tree is included into linux-next via various
branches at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
and is updated there most days
------------------------------------------------------
From: Yeoreum Yun <yeoreum.yun(a)arm.com>
Subject: arm64: kernel: initialize missing kexec_buf->random field
Date: Mon, 1 Dec 2025 10:51:18 +0000
Commit bf454ec31add ("kexec_file: allow to place kexec_buf randomly")
introduced the kexec_buf->random field to enable random placement of
kexec_buf.
However, this field was never properly initialized for kexec images that
do not need to be placed randomly, leading to the following UBSAN warning:
[ +0.364528] ------------[ cut here ]------------
[ +0.000019] UBSAN: invalid-load in ./include/linux/kexec.h:210:12
[ +0.000131] load of value 2 is not a valid value for type 'bool' (aka '_Bool')
[ +0.000003] CPU: 4 UID: 0 PID: 927 Comm: kexec Not tainted 6.18.0-rc7+ #3 PREEMPT(full)
[ +0.000002] Hardware name: QEMU QEMU Virtual Machine, BIOS 0.0.0 02/06/2015
[ +0.000000] Call trace:
[ +0.000001] show_stack+0x24/0x40 (C)
[ +0.000006] __dump_stack+0x28/0x48
[ +0.000002] dump_stack_lvl+0x7c/0xb0
[ +0.000002] dump_stack+0x18/0x34
[ +0.000001] ubsan_epilogue+0x10/0x50
[ +0.000002] __ubsan_handle_load_invalid_value+0xc8/0xd0
[ +0.000003] locate_mem_hole_callback+0x28c/0x2a0
[ +0.000003] kexec_locate_mem_hole+0xf4/0x2f0
[ +0.000001] kexec_add_buffer+0xa8/0x178
[ +0.000002] image_load+0xf0/0x258
[ +0.000001] __arm64_sys_kexec_file_load+0x510/0x718
[ +0.000002] invoke_syscall+0x68/0xe8
[ +0.000001] el0_svc_common+0xb0/0xf8
[ +0.000002] do_el0_svc+0x28/0x48
[ +0.000001] el0_svc+0x40/0xe8
[ +0.000002] el0t_64_sync_handler+0x84/0x140
[ +0.000002] el0t_64_sync+0x1bc/0x1c0
To address this, initialise kexec_buf->random field properly.
Link: https://lkml.kernel.org/r/20251201105118.2786335-1-yeoreum.yun@arm.com
Fixes: bf454ec31add ("kexec_file: allow to place kexec_buf randomly")
Signed-off-by: Yeoreum Yun <yeoreum.yun(a)arm.com>
Suggested-by: Breno Leitao <leitao(a)debian.org>
Reviewed-by: Breno Leitao <leitao(a)debian.org>
Cc: Catalin Marinas <catalin.marinas(a)arm.com>
Cc: Coiby Xu <coxu(a)redhat.com>
Cc: levi.yun <yeoreum.yun(a)arm.com>
Cc: Marc Rutland <mark.rutland(a)arm.com>
Cc: Will Deacon <will(a)kernel.org>
Cc: <stable(a)vger.kernel.org>
Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org>
---
arch/arm64/kernel/kexec_image.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
--- a/arch/arm64/kernel/kexec_image.c~arm64-kernel-initialize-missing-kexec_buf-random-field
+++ a/arch/arm64/kernel/kexec_image.c
@@ -41,7 +41,7 @@ static void *image_load(struct kimage *i
struct arm64_image_header *h;
u64 flags, value;
bool be_image, be_kernel;
- struct kexec_buf kbuf;
+ struct kexec_buf kbuf = {};
unsigned long text_offset, kernel_segment_number;
struct kexec_segment *kernel_segment;
int ret;
_
Patches currently in -mm which might be from yeoreum.yun(a)arm.com are
arm64-kernel-initialize-missing-kexec_buf-random-field.patch
Some DAMON sysfs directory setup functions generates its sub and sub-sub
directories. For example, 'monitoring_attrs/' directory setup creates
'intervals/' and 'intervals/intervals_goal/' directories under
'monitoring_attrs/' directory. When such sub-sub directories are
successfully made but followup setup is failed, the setup function
should recursively clean up the subdirectories.
However, such setup functions are only dereferencing sub directory
reference counters. As a result, under certain setup failures, the
sub-sub directories keep having non-zero reference counters. It means
the directories cannot be removed like zombies, and the memory for the
directories cannot be freed.
The user impact of this issue is limited due to the following reasons.
When the issue happens, the zombie directories are still taking the
path. Hence attempts to generate the directories again will fail,
without additional memory leak. This means the upper bound memory leak
is limited. Nonetheless this also implies controlling DAMON with a
feature that requires the setup-failed sysfs files will be impossible
until the system reboots.
Also, the setup operations are quite simple. The certain failures would
hence only rarely happen, and are difficult to artificially trigger.
SeongJae Park (4):
mm/damon/sysfs: cleanup intervals subdirs on attrs dir setup failure
mm/damon/sysfs: cleanup attrs subdirs on context dir setup failure
mm/damon/sysfs-scheme: cleanup quotas subdirs on scheme dir setup
failure
mm/damon/sysfs-scheme: cleanup access_pattern subdirs on scheme dir
setup failure
mm/damon/sysfs-schemes.c | 10 ++++++----
mm/damon/sysfs.c | 9 ++++++---
2 files changed, 12 insertions(+), 7 deletions(-)
base-commit: 6d039da6a260dd7919bebc70ebb65d250bb9c24e
--
2.47.3
The patch titled
Subject: mm/vma: fix anon_vma UAF on mremap() faulted, unfaulted merge
has been added to the -mm mm-hotfixes-unstable branch. Its filename is
mm-vma-fix-anon_vma-uaf-on-mremap-faulted-unfaulted-merge.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patche…
This patch will later appear in the mm-hotfixes-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Before you just go and hit "reply", please:
a) Consider who else should be cc'ed
b) Prefer to cc a suitable mailing list as well
c) Ideally: find the original patch on the mailing list and do a
reply-to-all to that, adding suitable additional cc's
*** Remember to use Documentation/process/submit-checklist.rst when testing your code ***
The -mm tree is included into linux-next via various
branches at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
and is updated there most days
------------------------------------------------------
From: Lorenzo Stoakes <lorenzo.stoakes(a)oracle.com>
Subject: mm/vma: fix anon_vma UAF on mremap() faulted, unfaulted merge
Date: Fri, 2 Jan 2026 20:55:20 +0000
Commit 879bca0a2c4f ("mm/vma: fix incorrectly disallowed anonymous VMA
merges") introduced the ability to merge previously unavailable VMA merge
scenarios.
The key piece of logic introduced was the ability to merge a faulted VMA
immediately next to an unfaulted VMA, which relies upon dup_anon_vma() to
correctly handle anon_vma state.
In the case of the merge of an existing VMA (that is changing properties
of a VMA and then merging if those properties are shared by adjacent
VMAs), dup_anon_vma() is invoked correctly.
However in the case of the merge of a new VMA, a corner case peculiar to
mremap() was missed.
The issue is that vma_expand() only performs dup_anon_vma() if the target
(the VMA that will ultimately become the merged VMA): is not the next VMA,
i.e. the one that appears after the range in which the new VMA is to be
established.
A key insight here is that in all other cases other than mremap(), a new
VMA merge either expands an existing VMA, meaning that the target VMA will
be that VMA, or would have anon_vma be NULL.
Specifically:
* __mmap_region() - no anon_vma in place, initial mapping.
* do_brk_flags() - expanding an existing VMA.
* vma_merge_extend() - expanding an existing VMA.
* relocate_vma_down() - no anon_vma in place, initial mapping.
In addition, we are in the unique situation of needing to duplicate
anon_vma state from a VMA that is neither the previous or next VMA being
merged with.
To account for this, introduce a new field in struct vma_merge_struct
specifically for the mremap() case, and update vma_expand() to explicitly
check for this case and invoke dup_anon_vma() to ensure anon_vma state is
correctly propagated.
This issue can be observed most directly by invoked mremap() to move
around a VMA and cause this kind of merge with the MREMAP_DONTUNMAP flag
specified.
This will result in unlink_anon_vmas() being called after failing to
duplicate anon_vma state to the target VMA, which results in the anon_vma
itself being freed with folios still possessing dangling pointers to the
anon_vma and thus a use-after-free bug.
This bug was discovered via a syzbot report, which this patch resolves.
The following program reproduces the issue (and is fixed by this patch):
#define _GNU_SOURCE
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <sys/mman.h>
#define RESERVED_PGS (100)
#define VMA_A_PGS (10)
#define VMA_B_PGS (10)
#define NUM_ITERS (1000)
static void trigger_bug(void)
{
unsigned long page_size = sysconf(_SC_PAGE_SIZE);
char *reserved, *ptr_a, *ptr_b;
/*
* The goal here is to achieve:
*
* mremap() with MREMAP_DONTUNMAP such that A and B merge:
*
* |-------------------------|
* | |
* | |-----------| |---------|
* v | unfaulted | | faulted |
* |-----------| |---------|
* B A
*
* Then unmap VMA A to trigger the bug.
*/
/* Reserve a region of memory to operate in. */
reserved = mmap(NULL, RESERVED_PGS * page_size, PROT_NONE,
MAP_PRIVATE | MAP_ANON, -1, 0);
if (reserved == MAP_FAILED) {
perror("mmap reserved");
exit(EXIT_FAILURE);
}
/* Map VMA A into place. */
ptr_a = mmap(&reserved[page_size], VMA_A_PGS * page_size,
PROT_READ | PROT_WRITE,
MAP_PRIVATE | MAP_ANON | MAP_FIXED, -1, 0);
if (ptr_a == MAP_FAILED) {
perror("mmap VMA A");
exit(EXIT_FAILURE);
}
/* Fault it in. */
ptr_a[0] = 'x';
/*
* Now move it out of the way so we can place VMA B in position,
* unfaulted.
*/
ptr_a = mremap(ptr_a, VMA_A_PGS * page_size, VMA_A_PGS * page_size,
MREMAP_FIXED | MREMAP_MAYMOVE, &reserved[50 * page_size]);
if (ptr_a == MAP_FAILED) {
perror("mremap VMA A out of the way");
exit(EXIT_FAILURE);
}
/* Map VMA B into place. */
ptr_b = mmap(&reserved[page_size + VMA_A_PGS * page_size],
VMA_B_PGS * page_size, PROT_READ | PROT_WRITE,
MAP_PRIVATE | MAP_ANON | MAP_FIXED, -1, 0);
if (ptr_b == MAP_FAILED) {
perror("mmap VMA B");
exit(EXIT_FAILURE);
}
/* Now move VMA A into position w/MREMAP_DONTUNMAP + free anon_vma. */
ptr_a = mremap(ptr_a, VMA_A_PGS * page_size, VMA_A_PGS * page_size,
MREMAP_FIXED | MREMAP_MAYMOVE | MREMAP_DONTUNMAP,
&reserved[page_size]);
if (ptr_a == MAP_FAILED) {
perror("mremap VMA A with MREMAP_DONTUNMAP");
exit(EXIT_FAILURE);
}
/* Finally, unmap VMA A which should trigger the bug. */
munmap(ptr_a, VMA_A_PGS * page_size);
/* Cleanup in case bug didn't trigger sufficiently visibly... */
munmap(reserved, RESERVED_PGS * page_size);
}
int main(void)
{
int i;
for (i = 0; i < NUM_ITERS; i++)
trigger_bug();
return EXIT_SUCCESS;
}
Link: https://lkml.kernel.org/r/20260102205520.986725-1-lorenzo.stoakes@oracle.com
Signed-off-by: Lorenzo Stoakes <lorenzo.stoakes(a)oracle.com>
Fixes: 879bca0a2c4f ("mm/vma: fix incorrectly disallowed anonymous VMA merges")
Reported-by: syzbot+b165fc2e11771c66d8ba(a)syzkaller.appspotmail.com
Closes: https://lore.kernel.org/all/694a2745.050a0220.19928e.0017.GAE@google.com/
Cc: David Hildenbrand (Red Hat) <david(a)kernel.org>
Cc: Jann Horn <jannh(a)google.com>
Cc: Jeongjun Park <aha310510(a)gmail.com>
Cc: levi.yun <yeoreum.yun(a)arm.com>
Cc: Liam Howlett <liam.howlett(a)oracle.com>
Cc: Rik van Riel <riel(a)surriel.com>
Cc: Vlastimil Babka <vbabka(a)suse.cz>
Cc: Pedro Falcato <pfalcato(a)suse.de>
Cc: <stable(a)vger.kernel.org>
Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org>
---
mm/vma.c | 58 ++++++++++++++++++++++++++++++++++++++++-------------
mm/vma.h | 3 ++
2 files changed, 47 insertions(+), 14 deletions(-)
--- a/mm/vma.c~mm-vma-fix-anon_vma-uaf-on-mremap-faulted-unfaulted-merge
+++ a/mm/vma.c
@@ -1130,26 +1130,50 @@ int vma_expand(struct vma_merge_struct *
mmap_assert_write_locked(vmg->mm);
vma_start_write(target);
- if (next && (target != next) && (vmg->end == next->vm_end)) {
+ if (next && vmg->end == next->vm_end) {
+ struct vm_area_struct *copied_from = vmg->copied_from;
int ret;
- sticky_flags |= next->vm_flags & VM_STICKY;
- remove_next = true;
- /* This should already have been checked by this point. */
- VM_WARN_ON_VMG(!can_merge_remove_vma(next), vmg);
- vma_start_write(next);
- /*
- * In this case we don't report OOM, so vmg->give_up_on_mm is
- * safe.
- */
- ret = dup_anon_vma(target, next, &anon_dup);
- if (ret)
- return ret;
+ if (target != next) {
+ sticky_flags |= next->vm_flags & VM_STICKY;
+ remove_next = true;
+ /* This should already have been checked by this point. */
+ VM_WARN_ON_VMG(!can_merge_remove_vma(next), vmg);
+ vma_start_write(next);
+ /*
+ * In this case we don't report OOM, so vmg->give_up_on_mm is
+ * safe.
+ */
+ ret = dup_anon_vma(target, next, &anon_dup);
+ if (ret)
+ return ret;
+ } else if (copied_from) {
+ vma_start_write(next);
+
+ /*
+ * We are copying from a VMA (i.e. mremap()'ing) to
+ * next, and thus must ensure that either anon_vma's are
+ * already compatible (in which case this call is a nop)
+ * or all anon_vma state is propagated to next
+ */
+ ret = dup_anon_vma(next, copied_from, &anon_dup);
+ if (ret)
+ return ret;
+ } else {
+ /* In no other case may the anon_vma differ. */
+ VM_WARN_ON_VMG(target->anon_vma != next->anon_vma, vmg);
+ }
}
/* Not merging but overwriting any part of next is not handled. */
VM_WARN_ON_VMG(next && !remove_next &&
next != target && vmg->end > next->vm_start, vmg);
+ /*
+ * We should only see a copy with next as the target on a new merge
+ * which sets the end to the next of next.
+ */
+ VM_WARN_ON_VMG(target == next && vmg->copied_from &&
+ vmg->end != next->vm_end, vmg);
/* Only handles expanding */
VM_WARN_ON_VMG(target->vm_start < vmg->start ||
target->vm_end > vmg->end, vmg);
@@ -1808,6 +1832,13 @@ struct vm_area_struct *copy_vma(struct v
VMG_VMA_STATE(vmg, &vmi, NULL, vma, addr, addr + len);
/*
+ * VMG_VMA_STATE() installs vma in middle, but this is a new VMA, inform
+ * merging logic correctly.
+ */
+ vmg.copied_from = vma;
+ vmg.middle = NULL;
+
+ /*
* If anonymous vma has not yet been faulted, update new pgoff
* to match new location, to increase its chance of merging.
*/
@@ -1828,7 +1859,6 @@ struct vm_area_struct *copy_vma(struct v
if (new_vma && new_vma->vm_start < addr + len)
return NULL; /* should never get here */
- vmg.middle = NULL; /* New VMA range. */
vmg.pgoff = pgoff;
vmg.next = vma_iter_next_rewind(&vmi, NULL);
new_vma = vma_merge_new_range(&vmg);
--- a/mm/vma.h~mm-vma-fix-anon_vma-uaf-on-mremap-faulted-unfaulted-merge
+++ a/mm/vma.h
@@ -106,6 +106,9 @@ struct vma_merge_struct {
struct anon_vma_name *anon_name;
enum vma_merge_state state;
+ /* If we are copying a VMA, which VMA are we copying from? */
+ struct vm_area_struct *copied_from;
+
/* Flags which callers can use to modify merge behaviour: */
/*
_
Patches currently in -mm which might be from lorenzo.stoakes(a)oracle.com are
mm-vma-fix-anon_vma-uaf-on-mremap-faulted-unfaulted-merge.patch
The patch below does not apply to the 6.18-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
To reproduce the conflict and resubmit, you may use the following commands:
git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.18.y
git checkout FETCH_HEAD
git cherry-pick -x 8a0e4bdddd1c998b894d879a1d22f1e745606215
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2025122925-victory-numeral-2346@gregkh' --subject-prefix 'PATCH 6.18.y' HEAD^..
Possible dependencies:
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 8a0e4bdddd1c998b894d879a1d22f1e745606215 Mon Sep 17 00:00:00 2001
From: Wei Yang <richard.weiyang(a)gmail.com>
Date: Thu, 6 Nov 2025 03:41:55 +0000
Subject: [PATCH] mm/huge_memory: merge uniform_split_supported() and
non_uniform_split_supported()
uniform_split_supported() and non_uniform_split_supported() share
significantly similar logic.
The only functional difference is that uniform_split_supported() includes
an additional check on the requested @new_order.
The reason for this check comes from the following two aspects:
* some file system or swap cache just supports order-0 folio
* the behavioral difference between uniform/non-uniform split
The behavioral difference between uniform split and non-uniform:
* uniform split splits folio directly to @new_order
* non-uniform split creates after-split folios with orders from
folio_order(folio) - 1 to new_order.
This means for non-uniform split or !new_order split we should check the
file system and swap cache respectively.
This commit unifies the logic and merge the two functions into a single
combined helper, removing redundant code and simplifying the split
support checking mechanism.
Link: https://lkml.kernel.org/r/20251106034155.21398-3-richard.weiyang@gmail.com
Fixes: c010d47f107f ("mm: thp: split huge page to any lower order pages")
Signed-off-by: Wei Yang <richard.weiyang(a)gmail.com>
Reviewed-by: Zi Yan <ziy(a)nvidia.com>
Cc: Zi Yan <ziy(a)nvidia.com>
Cc: "David Hildenbrand (Red Hat)" <david(a)kernel.org>
Cc: Baolin Wang <baolin.wang(a)linux.alibaba.com>
Cc: Barry Song <baohua(a)kernel.org>
Cc: Dev Jain <dev.jain(a)arm.com>
Cc: Lance Yang <lance.yang(a)linux.dev>
Cc: Liam Howlett <liam.howlett(a)oracle.com>
Cc: Lorenzo Stoakes <lorenzo.stoakes(a)oracle.com>
Cc: Nico Pache <npache(a)redhat.com>
Cc: Ryan Roberts <ryan.roberts(a)arm.com>
Cc: <stable(a)vger.kernel.org>
Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org>
diff --git a/include/linux/huge_mm.h b/include/linux/huge_mm.h
index b74708dc5b5f..19d4a5f52ca2 100644
--- a/include/linux/huge_mm.h
+++ b/include/linux/huge_mm.h
@@ -374,10 +374,8 @@ int __split_huge_page_to_list_to_order(struct page *page, struct list_head *list
unsigned int new_order, bool unmapped);
int min_order_for_split(struct folio *folio);
int split_folio_to_list(struct folio *folio, struct list_head *list);
-bool uniform_split_supported(struct folio *folio, unsigned int new_order,
- bool warns);
-bool non_uniform_split_supported(struct folio *folio, unsigned int new_order,
- bool warns);
+bool folio_split_supported(struct folio *folio, unsigned int new_order,
+ enum split_type split_type, bool warns);
int folio_split(struct folio *folio, unsigned int new_order, struct page *page,
struct list_head *list);
@@ -408,7 +406,7 @@ static inline int split_huge_page_to_order(struct page *page, unsigned int new_o
static inline int try_folio_split_to_order(struct folio *folio,
struct page *page, unsigned int new_order)
{
- if (!non_uniform_split_supported(folio, new_order, /* warns= */ false))
+ if (!folio_split_supported(folio, new_order, SPLIT_TYPE_NON_UNIFORM, /* warns= */ false))
return split_huge_page_to_order(&folio->page, new_order);
return folio_split(folio, new_order, page, NULL);
}
diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index 4118f330c55e..d79a4bb363de 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -3593,8 +3593,8 @@ static int __split_unmapped_folio(struct folio *folio, int new_order,
return 0;
}
-bool non_uniform_split_supported(struct folio *folio, unsigned int new_order,
- bool warns)
+bool folio_split_supported(struct folio *folio, unsigned int new_order,
+ enum split_type split_type, bool warns)
{
if (folio_test_anon(folio)) {
/* order-1 is not supported for anonymous THP. */
@@ -3602,48 +3602,41 @@ bool non_uniform_split_supported(struct folio *folio, unsigned int new_order,
"Cannot split to order-1 folio");
if (new_order == 1)
return false;
- } else if (IS_ENABLED(CONFIG_READ_ONLY_THP_FOR_FS) &&
- !mapping_large_folio_support(folio->mapping)) {
- /*
- * No split if the file system does not support large folio.
- * Note that we might still have THPs in such mappings due to
- * CONFIG_READ_ONLY_THP_FOR_FS. But in that case, the mapping
- * does not actually support large folios properly.
- */
- VM_WARN_ONCE(warns,
- "Cannot split file folio to non-0 order");
- return false;
- }
-
- /* Only swapping a whole PMD-mapped folio is supported */
- if (folio_test_swapcache(folio)) {
- VM_WARN_ONCE(warns,
- "Cannot split swapcache folio to non-0 order");
- return false;
- }
-
- return true;
-}
-
-/* See comments in non_uniform_split_supported() */
-bool uniform_split_supported(struct folio *folio, unsigned int new_order,
- bool warns)
-{
- if (folio_test_anon(folio)) {
- VM_WARN_ONCE(warns && new_order == 1,
- "Cannot split to order-1 folio");
- if (new_order == 1)
- return false;
- } else if (new_order) {
+ } else if (split_type == SPLIT_TYPE_NON_UNIFORM || new_order) {
if (IS_ENABLED(CONFIG_READ_ONLY_THP_FOR_FS) &&
!mapping_large_folio_support(folio->mapping)) {
+ /*
+ * We can always split a folio down to a single page
+ * (new_order == 0) uniformly.
+ *
+ * For any other scenario
+ * a) uniform split targeting a large folio
+ * (new_order > 0)
+ * b) any non-uniform split
+ * we must confirm that the file system supports large
+ * folios.
+ *
+ * Note that we might still have THPs in such
+ * mappings, which is created from khugepaged when
+ * CONFIG_READ_ONLY_THP_FOR_FS is enabled. But in that
+ * case, the mapping does not actually support large
+ * folios properly.
+ */
VM_WARN_ONCE(warns,
"Cannot split file folio to non-0 order");
return false;
}
}
- if (new_order && folio_test_swapcache(folio)) {
+ /*
+ * swapcache folio could only be split to order 0
+ *
+ * non-uniform split creates after-split folios with orders from
+ * folio_order(folio) - 1 to new_order, making it not suitable for any
+ * swapcache folio split. Only uniform split to order-0 can be used
+ * here.
+ */
+ if ((split_type == SPLIT_TYPE_NON_UNIFORM || new_order) && folio_test_swapcache(folio)) {
VM_WARN_ONCE(warns,
"Cannot split swapcache folio to non-0 order");
return false;
@@ -3711,11 +3704,7 @@ static int __folio_split(struct folio *folio, unsigned int new_order,
if (new_order >= old_order)
return -EINVAL;
- if (split_type == SPLIT_TYPE_UNIFORM && !uniform_split_supported(folio, new_order, true))
- return -EINVAL;
-
- if (split_type == SPLIT_TYPE_NON_UNIFORM &&
- !non_uniform_split_supported(folio, new_order, true))
+ if (!folio_split_supported(folio, new_order, split_type, /* warn = */ true))
return -EINVAL;
is_hzp = is_huge_zero_folio(folio);
Synopsys renamed DWC_usb32 IP to DWC_usb4 as of IP version 1.30. No
functional change except checking for the IP_NAME here. The driver will
treat the new IP_NAME as if it's DWC_usb32. Additional features for USB4
will be introduced and checked separately.
Cc: stable(a)vger.kernel.org
Signed-off-by: Thinh Nguyen <Thinh.Nguyen(a)synopsys.com>
---
drivers/usb/dwc3/core.c | 2 ++
drivers/usb/dwc3/core.h | 1 +
2 files changed, 3 insertions(+)
diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c
index 96f85eada047..f71b75465a60 100644
--- a/drivers/usb/dwc3/core.c
+++ b/drivers/usb/dwc3/core.c
@@ -993,6 +993,8 @@ static bool dwc3_core_is_valid(struct dwc3 *dwc)
reg = dwc3_readl(dwc->regs, DWC3_GSNPSID);
dwc->ip = DWC3_GSNPS_ID(reg);
+ if (dwc->ip == DWC4_IP)
+ dwc->ip = DWC32_IP;
/* This should read as U3 followed by revision number */
if (DWC3_IP_IS(DWC3)) {
diff --git a/drivers/usb/dwc3/core.h b/drivers/usb/dwc3/core.h
index a5fc92c4ffa3..45757169b672 100644
--- a/drivers/usb/dwc3/core.h
+++ b/drivers/usb/dwc3/core.h
@@ -1265,6 +1265,7 @@ struct dwc3 {
#define DWC3_IP 0x5533
#define DWC31_IP 0x3331
#define DWC32_IP 0x3332
+#define DWC4_IP 0x3430
u32 revision;
base-commit: 18514fd70ea4ca9de137bb3bceeac1bac4bcad75
--
2.28.0