Pull ARM fix from Russell King:
"Just one fix to the module freeing function that was declared __weak
when it should not have been. Thanks to Petr Pavlu for spotting this"
* tag 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rmk/linux:
ARM: 9458/1: module: Ensure the override of module_arch_freeing_init()
In f2fs_precache_extents(), For large files, It requires reading many
node blocks. Instead of reading each node block with synchronous I/O,
this patch applies readahead so that node blocks can be fetched in
advance.
It reduces the overhead of repeated sync reads and improves efficiency
when precaching extents of large files.
I created a file with the same largest extent and executed the test.
For this experiment, I set the file's largest extent with an offset of 0
and a size of 1GB. I configured the remaining area with 100MB extents.
5GB test file:
dd if=/dev/urandom of=test1 bs=1m count=5120
cp test1 test2
fsync test1
dd if=test1 of=test2 bs=1m skip=1024 seek=1024 count=100 conv=notrunc
dd if=test1 of=test2 bs=1m skip=1224 seek=1224 count=100 conv=notrunc
...
dd if=test1 of=test2 bs=1m skip=5024 seek=5024 count=100 conv=notrunc
reboot
I also created 10GB and 20GB files with large extents using the same
method.
ioctl(F2FS_IOC_PRECACHE_EXTENTS) test results are as follows:
+-----------+---------+---------+-----------+
| File size | Before | After | Reduction |
+-----------+---------+---------+-----------+
| 5GB | 101.8ms | 37.0ms | 72.1% |
| 10GB | 222.9ms | 56.0ms | 74.9% |
| 20GB | 446.2ms | 116.4ms | 73.9% |
+-----------+---------+---------+-----------+
Tested on a 256GB mobile device with an SM8750 chipset.
Reviewed-by: Sungjong Seo <sj1557.seo@samsung.com>
Reviewed-by: Sunmin Jeong <s_min.jeong@samsung.com>
Signed-off-by: Yunji Kang <yunji0.kang@samsung.com>
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Add a sanity check in __update_extent_tree_range() to detect any
zero-sized extent update.
Signed-off-by: wangzijie <wangzijie1@honor.com>
Signed-off-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
It is possible to hit a zero entry while traversing the vmas in unuse_mm()
called from swapoff path and accessing it causes the OOPS:
Unable to handle kernel NULL pointer dereference at virtual address
0000000000000446--> Loading the memory from offset 0x40 on the
XA_ZERO_ENTRY as address.
Mem abort info:
ESR = 0x0000000096000005
EC = 0x25: DABT (current EL), IL = 32 bits
SET = 0, FnV = 0
EA = 0, S1PTW = 0
FSC = 0x05: level 1 translation fault
The issue is manifested from the below race between the fork() on a
process and swapoff:
fork(dup_mmap()) swapoff(unuse_mm)
--------------- -----------------
1) Identical mtree is built using
__mt_dup().
2) copy_pte_range()-->
copy_nonpresent_pte():
The dst mm is added into the
mmlist to be visible to the
swapoff operation.
3) Fatal signal is sent to the parent
process(which is the current during the
fork) thus skip the duplication of the
vmas and mark the vma range with
XA_ZERO_ENTRY as a marker for this process
that helps during exit_mmap().
4) swapoff is tried on the
'mm' added to the 'mmlist' as
part of the 2.
5) unuse_mm(), that iterates
through the vma's of this 'mm'
will hit the non-NULL zero entry
and operating on this zero entry
as a vma is resulting into the
oops.
The proper fix would be around not exposing this partially-valid tree to
others when droping the mmap lock, which is being solved with [1]. A
simpler solution would be checking for MMF_UNSTABLE, as it is set if
mm_struct is not fully initialized in dup_mmap().
Thanks to Liam/Lorenzo/David for all the suggestions in fixing this
issue.
Link: https://lkml.kernel.org/r/20250924181138.1762750-1-charan.kalla@oss.qualcomm.com
Link: https://lore.kernel.org/all/20250815191031.3769540-1-Liam.Howlett@oracle.com/ [1]
Fixes: d240629148 ("fork: use __mt_dup() to duplicate maple tree in dup_mmap()")
Signed-off-by: Charan Teja Kalla <charan.kalla@oss.qualcomm.com>
Suggested-by: David Hildenbrand <david@redhat.com>
Cc: Baoquan He <bhe@redhat.com>
Cc: Barry Song <baohua@kernel.org>
Cc: Chris Li <chrisl@kernel.org>
Cc: Kairui Song <kasong@tencent.com>
Cc: Kemeng Shi <shikemeng@huaweicloud.com>
Cc: Liam Howlett <liam.howlett@oracle.com>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Nhat Pham <nphamcs@gmail.com>
Cc: Peng Zhang <zhangpeng.00@bytedance.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
hugetlb_vmdelete_list() uses trylock to acquire VMA locks during truncate
operations. As per the original design in commit 40549ba8f8 ("hugetlb:
use new vma_lock for pmd sharing synchronization"), if the trylock fails
or the VMA has no lock, it should skip that VMA. Any remaining mapped
pages are handled by remove_inode_hugepages() which is called after
hugetlb_vmdelete_list() and uses proper lock ordering to guarantee
unmapping success.
Currently, when hugetlb_vma_trylock_write() returns success (1) for VMAs
without shareable locks, the code proceeds to call unmap_hugepage_range().
This causes assertion failures in huge_pmd_unshare() →
hugetlb_vma_assert_locked() because no lock is actually held:
WARNING: CPU: 1 PID: 6594 Comm: syz.0.28 Not tainted
Call Trace:
hugetlb_vma_assert_locked+0x1dd/0x250
huge_pmd_unshare+0x2c8/0x540
__unmap_hugepage_range+0x6e3/0x1aa0
unmap_hugepage_range+0x32e/0x410
hugetlb_vmdelete_list+0x189/0x1f0
Fix by using goto to ensure locks acquired by trylock are always released,
even when skipping VMAs without shareable locks.
Link: https://lkml.kernel.org/r/20250926033255.10930-1-kartikey406@gmail.com
Fixes: 40549ba8f8 ("hugetlb: use new vma_lock for pmd sharing synchronization")
Signed-off-by: Deepanshu Kartikey <kartikey406@gmail.com>
Reported-by: syzbot+f26d7c75c26ec19790e7@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=f26d7c75c26ec19790e7
Suggested-by: Andrew Morton <akpm@linux-foundation.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Oscar Salvador <osalvador@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
There is a boot failure when both CONFIG_DEBUG_KMEMLEAK and
CONFIG_MEM_ALLOC_PROFILING are enabled.
BUG: kernel NULL pointer dereference, address: 0000000000000000
RIP: 0010:__alloc_tagging_slab_alloc_hook+0x181/0x2f0
Call Trace:
kmem_cache_alloc_noprof+0x1c8/0x5c0
__alloc_object+0x2f/0x290
__create_object+0x22/0x80
kmemleak_init+0x122/0x190
mm_core_init+0xb6/0x160
start_kernel+0x39f/0x920
x86_64_start_reservations+0x18/0x30
x86_64_start_kernel+0x104/0x120
common_startup_64+0x12c/0x138
In kmemleak, mem_pool_alloc() directly calls kmem_cache_alloc_noprof(), as
a result, current->alloc_tag is NULL, leading to a null pointer
dereference.
Move the checks for SLAB_NO_OBJ_EXT, SLAB_NOLEAKTRACE, and
__GFP_NO_OBJ_EXT to the parent function __alloc_tagging_slab_alloc_hook()
to fix this.
Also this distinguishes the SLAB_NOLEAKTRACE case between the actual
memory allocation failures case, make CODETAG_FLAG_INACCURATE more
accurate.
Link: https://lkml.kernel.org/r/20250926080659.741991-1-ranxiaokai627@163.com
Fixes: b9e2f58ffb ("alloc_tag: mark inaccurate allocation counters in /proc/allocinfo output")
Signed-off-by: Ran Xiaokai <ran.xiaokai@zte.com.cn>
Reviewed-by: Harry Yoo <harry.yoo@oracle.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: Suren Baghdasaryan <surenb@google.com>
Cc: Christoph Lameter (Ampere) <cl@gentwo.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Shakeel Butt <shakeel.butt@linux.dev>
Cc: Usama Arif <usamaarif642@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Commit 79359d6d24 ("hugetlb: perform vmemmap optimization on a list of
pages") batches the submission of HugeTLB vmemmap optimization (HVO)
during hugepage reservation. With HVO enabled, hugepages obtained from
the buddy allocator are not submitted for optimization and their
struct-page memory is therefore not released—until the entire
reservation request has been satisfied. As a result, any struct-page
memory freed in the course of the allocation cannot be reused for the
ongoing reservation, artificially limiting the number of huge pages that
can ultimately be provided.
As commit b1222550fb ("mm/hugetlb: do pre-HVO for bootmem allocated
pages") already applies early HVO to bootmem-allocated huge pages, this
patch extends the same benefit to non-bootmem pages by incrementally
submitting them for HVO as they are allocated, thereby returning
struct-page memory to the buddy allocator in real time. The change raises
the maximum 2 MiB hugepage reservation from just under 376 GB to more than
381 GB on a 384 GB x86 VM.
Link: https://lkml.kernel.org/r/20250919092353.41671-1-lizhe.67@bytedance.com
Signed-off-by: Li Zhe <lizhe.67@bytedance.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Oscar Salvador <osalvador@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Patch series "mm/ksm: Fix incorrect accounting of KSM counters during
fork", v3.
The first patch in this series fixes the incorrect accounting of KSM
counters such as ksm_merging_pages, ksm_rmap_items, and the global
ksm_zero_pages during fork.
The following patch add a selftest to verify the ksm_merging_pages counter
was updated correctly during fork.
Test Results
============
Without the first patch
-----------------------
# [RUN] test_fork_ksm_merging_page_count
not ok 10 ksm_merging_page in child: 32
With the first patch
--------------------
# [RUN] test_fork_ksm_merging_page_count
ok 10 ksm_merging_pages is not inherited after fork
This patch (of 2):
Currently, the KSM-related counters in `mm_struct`, such as
`ksm_merging_pages`, `ksm_rmap_items`, and `ksm_zero_pages`, are inherited
by the child process during fork. This results in inconsistent
accounting.
When a process uses KSM, identical pages are merged and an rmap item is
created for each merged page. The `ksm_merging_pages` and
`ksm_rmap_items` counters are updated accordingly. However, after a fork,
these counters are copied to the child while the corresponding rmap items
are not. As a result, when the child later triggers an unmerge, there are
no rmap items present in the child, so the counters remain stale, leading
to incorrect accounting.
A similar issue exists with `ksm_zero_pages`, which maintains both a
global counter and a per-process counter. During fork, the per-process
counter is inherited by the child, but the global counter is not
incremented. Since the child also references zero pages, the global
counter should be updated as well. Otherwise, during zero-page unmerge,
both the global and per-process counters are decremented, causing the
global counter to become inconsistent.
To fix this, ksm_merging_pages and ksm_rmap_items are reset to 0 during
fork, and the global ksm_zero_pages counter is updated with the
per-process ksm_zero_pages value inherited by the child. This ensures
that KSM statistics remain accurate and reflect the activity of each
process correctly.
Link: https://lkml.kernel.org/r/cover.1758648700.git.donettom@linux.ibm.com
Link: https://lkml.kernel.org/r/7b9870eb67ccc0d79593940d9dbd4a0b39b5d396.1758648700.git.donettom@linux.ibm.com
Fixes: 7609385337 ("ksm: count ksm merging pages for each process")
Fixes: cb4df4cae4 ("ksm: count allocated ksm rmap_items for each process")
Fixes: e2942062e0 ("ksm: count all zero pages placed by KSM")
Signed-off-by: Donet Tom <donettom@linux.ibm.com>
Reviewed-by: Chengming Zhou <chengming.zhou@linux.dev>
Acked-by: David Hildenbrand <david@redhat.com>
Cc: Aboorva Devarajan <aboorvad@linux.ibm.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Donet Tom <donettom@linux.ibm.com>
Cc: "Ritesh Harjani (IBM)" <ritesh.list@gmail.com>
Cc: Wei Yang <richard.weiyang@gmail.com>
Cc: xu xin <xu.xin16@zte.com.cn>
Cc: <stable@vger.kernel.org> [6.6+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
When using vmalloc with VM_ALLOW_HUGE_VMAP flag, it will set the alignment
to PMD_SIZE internally, if it deems huge mappings to be eligible.
Therefore, setting the alignment in execmem_vmalloc is redundant. Apart
from this, it also reduces the probability of allocation in case vmalloc
fails to allocate hugepages - in the fallback case, vmalloc tries to use
the original alignment and allocate basepages, which unfortunately will
again be PMD_SIZE passed over from execmem_vmalloc, thus constraining the
search for a free space in vmalloc region.
Therefore, remove this constraint.
Link: https://lkml.kernel.org/r/20250918093453.75676-1-dev.jain@arm.com
Signed-off-by: Dev Jain <dev.jain@arm.com>
Reviewed-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
The kernel currently does not mlock large folios when adding them to rmap,
stating that it is difficult to confirm that the folio is fully mapped and
safe to mlock it.
This leads to a significant undercount of Mlocked in /proc/meminfo,
causing problems in production where the stat was used to estimate system
utilization and determine if load shedding is required.
However, nowadays the caller passes a number of pages of the folio that
are getting mapped, making it easy to check if the entire folio is mapped
to the VMA.
mlock the folio on rmap if it is fully mapped to the VMA.
Mlocked in /proc/meminfo can still undercount, but the value is closer the
truth and is useful for userspace.
Link: https://lkml.kernel.org/r/20250923110711.690639-7-kirill@shutemov.name
Signed-off-by: Kiryl Shutsemau <kas@kernel.org>
Acked-by: David Hildenbrand <david@redhat.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Shakeel Butt <shakeel.butt@linux.dev>
Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
finish_fault() uses per-page fault for file folios. This only occurs for
file folios smaller than PMD_SIZE.
The comment suggests that this approach prevents RSS inflation. However,
it only prevents RSS accounting. The folio is still mapped to the
process, and the fact that it is mapped by a single PTE does not affect
memory pressure. Additionally, the kernel's ability to map large folios
as PMD if they are large enough does not support this argument.
When possible, map large folios in one shot. This reduces the number of
minor page faults and allows for TLB coalescing.
Mapping large folios at once will allow the rmap code to mlock it on add,
as it will recognize that it is fully mapped and mlocking is safe.
Link: https://lkml.kernel.org/r/20250923110711.690639-5-kirill@shutemov.name
Signed-off-by: Kiryl Shutsemau <kas@kernel.org>
Reviewed-by: Shakeel Butt <shakeel.butt@linux.dev>
Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
The mlock_vma_folio() function requires the page table lock to be held in
order to safely mlock the folio. However, folio_referenced_one() mlocks a
large folios outside of the page_vma_mapped_walk() loop where the page
table lock has already been dropped.
Rework the mlock logic to use the same code path inside the loop for both
large and small folios.
Use PVMW_PGTABLE_CROSSED to detect when the folio is mapped across a page
table boundary.
[akpm@linux-foundation.org: s/CROSSSED/CROSSED/]
Link: https://lkml.kernel.org/r/20250923110711.690639-3-kirill@shutemov.name
Signed-off-by: Kiryl Shutsemau <kas@kernel.org>
Reviewed-by: Shakeel Butt <shakeel.butt@linux.dev>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Patch series "mm: Improve mlock tracking for large folios", v3.
The patchset includes several fixes and improvements related to mlock
tracking of large folios.
The main objective is to reduce the undercount of Mlocked memory in
/proc/meminfo and improve the accuracy of the statistics.
Patches 1-2:
These patches address a minor race condition in folio_referenced_one()
related to mlock_vma_folio().
Currently, mlock_vma_folio() is called on large folio without the page
table lock, which can result in a race condition with unmap (i.e.
MADV_DONTNEED). This can lead to partially mapped folios on the
unevictable LRU list.
While not a significant issue, I do not believe backporting is necessary.
Patch 3:
This patch adds mlocking logic similar to folio_referenced_one() to
try_to_unmap_one(), allowing for mlocking of large folios where possible.
Patch 4-5:
These patches modifies finish_fault() and faultaround to map in the entire
folio when possible, enabling efficient mlocking upon addition to the
rmap.
Patch 6:
This patch makes rmap mlock large folios if they are fully mapped,
addressing the primary source of mlock undercount for large folios.
This patch (of 6):
Add a PVMW_PGTABLE_CROSSSED flag that page_vma_mapped_walk() will set if
the page is mapped across page table boundary. Unlike other PVMW_* flags,
this one is result of page_vma_mapped_walk() and not set by the caller.
folio_referenced_one() will use it to detect if it safe to mlock the
folio.
[akpm@linux-foundation.org: s/CROSSSED/CROSSED/]
Link: https://lkml.kernel.org/r/20250923110711.690639-1-kirill@shutemov.name
Link: https://lkml.kernel.org/r/20250923110711.690639-2-kirill@shutemov.name
Signed-off-by: Kiryl Shutsemau <kas@kernel.org>
Reviewed-by: Shakeel Butt <shakeel.butt@linux.dev>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Commit 56ae0bb349 ("mm: compaction: convert to use a folio in
isolate_migratepages_block()") converts api from page to folio. But the
low_pfn advance for hugetlb page seems wrong when low_pfn doesn't point to
head page.
Originally, if page is a hugetlb tail page, compound_nr() return 1, which
means low_pfn only advance one in next iteration. After the change,
low_pfn would advance more than the hugetlb range, since folio_nr_pages()
always return total number of the large page. This results in skipping
some range to isolate and then to migrate.
The worst case for alloc_contig is it does all the isolation and
migration, but finally find some range is still not isolated. And then
undo all the work and try a new range.
Advance low_pfn to the end of hugetlb.
Link: https://lkml.kernel.org/r/20250910092240.3981-1-richard.weiyang@gmail.com
Fixes: 56ae0bb349 ("mm: compaction: convert to use a folio in isolate_migratepages_block()")
Signed-off-by: Wei Yang <richard.weiyang@gmail.com>
Acked-by: Zi Yan <ziy@nvidia.com>
Cc: "Vishal Moola (Oracle)" <vishal.moola@gmail.com>
Cc: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Brendan Jackman <jackmanb@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Wei Yang <richard.weiyang@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Add support for SEEK_DATA and SEEK_HOLE lseek() whence values.
These allow much faster searches for holes and data in sparse files, which
can significantly speed up file copying, e.g.
before (GNU coreutils, Debian 13):
cp --sparse=always big-file /
took real 11m58s, user 0m5.764s, sys 11m48s
after:
real 0.047s, user 0.000s, sys 0.027s
Where big-file has a 256 GB hole followed by 47 KB of data.
Link: https://lkml.kernel.org/r/20250923220652.568416-3-phillip@squashfs.org.uk
Signed-off-by: Phillip Lougher <phillip@squashfs.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Patch series "Squashfs: performance improvement and a sanity check".
This patchset adds an additional sanity check when reading regular file
inodes, and adds support for SEEK_DATA/SEEK_HOLE lseek() whence values.
This patch (of 2):
Add an additional sanity check when reading regular file inodes.
A regular file if the file size is an exact multiple of the filesystem
block size cannot have a fragment. This is because by definition a
fragment block stores tailends which are not a whole block in size.
Link: https://lkml.kernel.org/r/20250923220652.568416-1-phillip@squashfs.org.uk
Link: https://lkml.kernel.org/r/20250923220652.568416-2-phillip@squashfs.org.uk
Signed-off-by: Phillip Lougher <phillip@squashfs.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
If a process calls prctl(PR_SET_PDEATHSIG) at the same time that the
parent process exits, the child will write to me->pdeath_sig at the same
time the parent is reading it. Since there is no synchronization, this is
a data race.
Worse, it is possible that a subsequent call to getppid() can continue to
return the previous parent process ID without the parent death signal
being delivered. This happens in the following scenario:
parent child
forget_original_parent() prctl(PR_SET_PDEATHSIG, SIGKILL)
sys_prctl()
me->pdeath_sig = SIGKILL;
getppid();
RCU_INIT_POINTER(t->real_parent, reaper);
if (t->pdeath_signal) /* reads stale me->pdeath_sig */
group_send_sig_info(t->pdeath_signal, ...);
And in the following:
parent child
forget_original_parent()
RCU_INIT_POINTER(t->real_parent, reaper);
/* also no barrier */
if (t->pdeath_signal) /* reads stale me->pdeath_sig */
group_send_sig_info(t->pdeath_signal, ...);
prctl(PR_SET_PDEATHSIG, SIGKILL)
sys_prctl()
me->pdeath_sig = SIGKILL;
getppid(); /* reads old ppid() */
As a result, the following pattern is racy:
pid_t parent_pid = getpid();
pid_t child_pid = fork();
if (child_pid == -1) {
/* handle error... */
return;
}
if (child_pid == 0) {
if (prctl(PR_SET_PDEATHSIG, SIGKILL) != 0) {
/* handle error */
_exit(126);
}
if (getppid() != parent_pid) {
/* parent died already */
raise(SIGKILL);
}
/* keep going in child */
}
/* keep going in parent */
If the parent is killed at exactly the wrong time, the child process can
(wrongly) stay running.
I didn't manage to reproduce this in my testing, but I'm pretty sure the
race is real. KCSAN is probably the best way to spot the race.
Fix the bug by holding tasklist_lock for reading whenever pdeath_signal is
being written to. This prevents races on me->pdeath_sig, and the locking
and unlocking of the rwlock provide the needed memory barriers. If
prctl(PR_SET_PDEATHSIG) happens before the parent exits, the signal will
be sent. If it happens afterwards, a subsequent getppid() will return the
new value.
Link: https://lkml.kernel.org/r/20250913-fix-prctl-pdeathsig-race-v1-1-44e2eb426fe9@gmail.com
Signed-off-by: Demi Marie Obenour <demiobenour@gmail.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Mateusz Guzik <mjguzik@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Syzkaller reports a "KMSAN: uninit-value in squashfs_get_parent" bug.
This is caused by open_by_handle_at() being called with a file handle
containing an invalid parent inode number. In particular the inode number
is that of a symbolic link, rather than a directory.
Squashfs_get_parent() gets called with that symbolic link inode, and
accesses the parent member field.
unsigned int parent_ino = squashfs_i(inode)->parent;
Because non-directory inodes in Squashfs do not have a parent value, this
is uninitialised, and this causes an uninitialised value access.
The fix is to initialise parent with the invalid inode 0, which will cause
an EINVAL error to be returned.
Regular inodes used to share the parent field with the block_list_start
field. This is removed in this commit to enable the parent field to
contain the invalid inode number 0.
Link: https://lkml.kernel.org/r/20250918233308.293861-1-phillip@squashfs.org.uk
Fixes: 122601408d ("Squashfs: export operations")
Signed-off-by: Phillip Lougher <phillip@squashfs.org.uk>
Reported-by: syzbot+157bdef5cf596ad0da2c@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/all/68cc2431.050a0220.139b6.0001.GAE@google.com/
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
kho_fill_kimage() only checks for KHO being enabled before filling in the
FDT to the image. KHO being enabled does not mean that the kernel has
data to hand over. That happens when KHO is finalized.
When a kexec is done with KHO enabled but not finalized, the FDT page is
allocated but not initialized. FDT initialization happens after finalize.
This means the KHO segment is filled in but the FDT contains garbage
data.
This leads to the below error messages in the next kernel:
[ 0.000000] KHO: setup: handover FDT (0x10116b000) is invalid: -9
[ 0.000000] KHO: disabling KHO revival: -22
There is no problem in practice, and the next kernel boots and works fine.
But this still leads to misleading error messages and garbage being
handed over.
Only fill in KHO segment when KHO is finalized. When KHO is not enabled,
the debugfs interface is not created and there is no way to finalize it
anyway. So the check for kho_enable is not needed, and kho_out.finalize
alone is enough.
Link: https://lkml.kernel.org/r/20250918170617.91413-1-pratyush@kernel.org
Fixes: 3bdecc3c93 ("kexec: add KHO support to kexec file loads")
Signed-off-by: Pratyush Yadav <pratyush@kernel.org>
Reviewed-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Cc: Alexander Graf <graf@amazon.com>
Cc: Baoquan He <bhe@redhat.com>
Cc: Changyuan Lyu <changyuanl@google.com>
Cc: Jason Gunthorpe <jgg@nvidia.com>
Cc: Pasha Tatashin <pasha.tatashin@soleen.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Pull tracing fixes from Steven Rostedt:
- Fix buffer overflow in osnoise_cpu_write()
The allocated buffer to read user space did not add a nul terminating
byte after copying from user the string. It then reads the string,
and if user space did not add a nul byte, the read will continue
beyond the string.
Add a nul terminating byte after reading the string.
- Fix missing check for lockdown on tracing
There's a path from kprobe events or uprobe events that can update
the tracing system even if lockdown on tracing is activate. Add a
check in the dynamic event path.
- Add a recursion check for the function graph return path
Now that fprobes can hook to the function graph tracer and call
different code between the entry and the exit, the exit code may now
call functions that are not called in entry. This means that the exit
handler can possibly trigger recursion that is not caught and cause
the system to crash.
Add the same recursion checks in the function exit handler as exists
in the entry handler path.
* tag 'trace-v6.17-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
tracing: fgraph: Protect return handler from recursion loop
tracing: dynevent: Add a missing lockdown check on dynevent
tracing/osnoise: Fix slab-out-of-bounds in _parse_integer_limit()
Pull spi fixes from Mark Brown:
"A few final driver specific fixes that have been sitting in -next for
a bit.
The OMAP issue is likely to come up very infrequently since mixed
configuration SPI buses are rare and the Cadence issue is specific to
SoCFPGA systems"
* tag 'spi-fix-v6.17-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi:
spi: omap2-mcspi: drive SPI_CLK on transfer_setup()
spi: cadence-qspi: defer runtime support on socfpga if reset bit is enabled
On the 1824c output channel 4 left/right is the S/PDIF output,
so this needs to be able to be set.
I'm guessing that for the 1810c since it has no output channel 4,
it does not matter what the gain value of this channel is set to.
Signed-off-by: Roy Vegard Ovesen <roy.vegard.ovesen@gmail.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
A reasonable initial mix for the 1824c is the one that
Presonus Universal Control calls bypass.
It mutes all the physical inputs, and connects
Daw channel 1 to Line out channel 1 (left)
Daw channel 2 to Line out channel 2 (right)
Daw channel 3 to Line out channel 3 (left)
etc.
To get the most out of the 1824c a mixer application like
Universal Control is needed. One is available for linux
Link: https://github.com/royvegard/baton
Signed-off-by: Roy Vegard Ovesen <roy.vegard.ovesen@gmail.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Pull misc fixes from Andrew Morton:
"7 hotfixes. 4 are cc:stable and the remainder address post-6.16 issues
or aren't considered necessary for -stable kernels. 6 of these fixes
are for MM.
All singletons, please see the changelogs for details"
* tag 'mm-hotfixes-stable-2025-09-27-22-35' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm:
include/linux/pgtable.h: convert arch_enter_lazy_mmu_mode() and friends to static inlines
mm/damon/sysfs: do not ignore callback's return value in damon_sysfs_damon_call()
mailmap: add entry for Bence Csókás
fs/proc/task_mmu: check p->vec_buf for NULL
kmsan: fix out-of-bounds access to shadow memory
mm/hugetlb: fix copy_hugetlb_page_range() to use ->pt_share_count
mm/hugetlb: fix folio is still mapped when deleted
ASoC: Updates for v6.18 round 2
Some more updates for v6.18, mostly fixes for the earlier pull request
with some cleanups and more minor fixes for older code. We do have one
new driver, the TI TAS2783A, and some quirks for new platforms.
Alexandre Belloni
Linus Torvalds
Qinxin Xia
Chao Yu
Yunji Kang
Charan Teja Kalla
David Hildenbrand
Wei Yang
Deepanshu Kartikey
Ran Xiaokai
Lance Yang
Xie Yuanbin
Li Zhe
Donet Tom
Dev Jain
Manish Kumar
Kiryl Shutsemau
Phillip Lougher
Sahil Chandna
Sibi Sankar
Johan Hovold
Johannes Berg
Dan Carpenter
Suchit Karunakaran
Alistair Popple
Demi Marie Obenour
Pratyush Yadav
Roy Vegard Ovesen
Takashi Iwai