pagemap_scan_pmd_entry() checks if uffd-wp is set on each pte to avoid
unnecessary if set. However it was previously checking with
`pte_uffd_wp(ptep_get(pte))` without first confirming that the pte was
present. It is only valid to call pte_uffd_wp() for present ptes. For
swap ptes, pte_swp_uffd_wp() must be called because the uffd-wp bit may be
kept in a different position, depending on the arch.
This was leading to test failures in the pagemap_ioctl mm selftest, when
bringing up uffd-wp support on arm64 due to incorrectly interpretting the
uffd-wp status of migration entries.
Let's fix this by using the correct check based on pte_present(). While
we are at it, let's pass the pte to make_uffd_wp_pte() to avoid the
pointless extra ptep_get() which can't be optimized out due to READ_ONCE()
on many arches.
Link: https://lkml.kernel.org/r/20240429114104.182890-1-ryan.roberts@arm.com
Fixes: 12f6b01a0b ("fs/proc/task_mmu: add fast paths to get/clear PAGE_IS_WRITTEN flag")
Closes: https://lore.kernel.org/linux-arm-kernel/ZiuyGXt0XWwRgFh9@x1n/
Signed-off-by: Ryan Roberts <ryan.roberts@arm.com>
Acked-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Muhammad Usama Anjum <usama.anjum@collabora.com>
Tested-by: Muhammad Usama Anjum <usama.anjum@collabora.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
make_uffd_wp_pte() was previously doing:
pte = ptep_get(ptep);
ptep_modify_prot_start(ptep);
pte = pte_mkuffd_wp(pte);
ptep_modify_prot_commit(ptep, pte);
But if another thread accessed or dirtied the pte between the first 2
calls, this could lead to loss of that information. Since
ptep_modify_prot_start() gets and clears atomically, the following is the
correct pattern and prevents any possible race. Any access after the
first call would see an invalid pte and cause a fault:
pte = ptep_modify_prot_start(ptep);
pte = pte_mkuffd_wp(pte);
ptep_modify_prot_commit(ptep, pte);
Link: https://lkml.kernel.org/r/20240429114017.182570-1-ryan.roberts@arm.com
Fixes: 52526ca7fd ("fs/proc/task_mmu: implement IOCTL to get and optionally clear info about PTEs")
Signed-off-by: Ryan Roberts <ryan.roberts@arm.com>
Acked-by: David Hildenbrand <david@redhat.com>
Cc: Muhammad Usama Anjum <usama.anjum@collabora.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
vm_map_ram() uses IS_ERR() to validate the return value of vb_alloc(). If
vm_map_ram(page, 0, 0) is executed, vb_alloc(0, GFP_KERNEL) would return
NULL. In such a case, IS_ERR() cannot handle the return value and lead to
kernel panic by vmap_pages_range_noflush() at last. To resolve this
issue, return ERR_PTR(-EINVAL) if the size is 0.
Link: https://lkml.kernel.org/r/20240426024149.21176-1-hailong.liu@oppo.com
Reviewed-by: Barry Song <baohua@kernel.org>
Reviewed-by: Uladzislau Rezki (Sony) <urezki@gmail.com>
Signed-off-by: Hailong.Liu <hailong.liu@oppo.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Lorenzo Stoakes <lstoakes@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
See commit f2c817bed5 ("mm: use memalloc_nofs_save in readahead path"),
ensure that page_cache_ra_order() do not attempt to reclaim file-backed
pages too, or it leads to a deadlock, found issue when test ext4 large
folio.
INFO: task DataXceiver for:7494 blocked for more than 120 seconds.
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:DataXceiver for state:D stack:0 pid:7494 ppid:1 flags:0x00000200
Call trace:
__switch_to+0x14c/0x240
__schedule+0x82c/0xdd0
schedule+0x58/0xf0
io_schedule+0x24/0xa0
__folio_lock+0x130/0x300
migrate_pages_batch+0x378/0x918
migrate_pages+0x350/0x700
compact_zone+0x63c/0xb38
compact_zone_order+0xc0/0x118
try_to_compact_pages+0xb0/0x280
__alloc_pages_direct_compact+0x98/0x248
__alloc_pages+0x510/0x1110
alloc_pages+0x9c/0x130
folio_alloc+0x20/0x78
filemap_alloc_folio+0x8c/0x1b0
page_cache_ra_order+0x174/0x308
ondemand_readahead+0x1c8/0x2b8
page_cache_async_ra+0x68/0xb8
filemap_readahead.isra.0+0x64/0xa8
filemap_get_pages+0x3fc/0x5b0
filemap_splice_read+0xf4/0x280
ext4_file_splice_read+0x2c/0x48 [ext4]
vfs_splice_read.part.0+0xa8/0x118
splice_direct_to_actor+0xbc/0x288
do_splice_direct+0x9c/0x108
do_sendfile+0x328/0x468
__arm64_sys_sendfile64+0x8c/0x148
invoke_syscall+0x4c/0x118
el0_svc_common.constprop.0+0xc8/0xf0
do_el0_svc+0x24/0x38
el0_svc+0x4c/0x1f8
el0t_64_sync_handler+0xc0/0xc8
el0t_64_sync+0x188/0x190
Link: https://lkml.kernel.org/r/20240426112938.124740-1-wangkefeng.wang@huawei.com
Fixes: 793917d997 ("mm/readahead: Add large folio readahead")
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Zhang Yi <yi.zhang@huawei.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
While testing lib/test_xarray in userspace I've noticed we can fail with:
make -C tools/testing/radix-tree
./tools/testing/radix-tree/xarray
BUG at check_xa_multi_store_adv_add:749
xarray: 0x55905fb21a00x head 0x55905fa1d8e0x flags 0 marks 0 0 0
0: 0x55905fa1d8e0x
xarray: ../../../lib/test_xarray.c:749: check_xa_multi_store_adv_add: Assertion `0' failed.
Aborted
We get a failure with a BUG_ON(), and that is because we actually can
fail due to -ENOMEM, the check in xas_nomem() will fix this for us so
it makes no sense to expect no failure inside the loop. So modify the
check and since this is also useful for instructional purposes clarify
the situation.
The check for XA_BUG_ON(xa, xa_load(xa, index) != p) is already done
at the end of the loop so just remove the bogus on inside the loop.
With this we now pass the test in both kernel and userspace:
In userspace:
./tools/testing/radix-tree/xarray
XArray: 149092856 of 149092856 tests passed
In kernel space:
XArray: 148257077 of 148257077 tests passed
Link: https://lkml.kernel.org/r/20240423192221.301095-3-mcgrof@kernel.org
Fixes: a60cc288a1 ("test_xarray: add tests for advanced multi-index use")
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
Cc: Daniel Gomez <da.gomez@samsung.com>
Cc: Darrick J. Wong <djwong@kernel.org>
Cc: Dave Chinner <david@fromorbit.com>
Cc: "Liam R. Howlett" <Liam.Howlett@oracle.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Pankaj Raghav <p.raghav@samsung.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Patch series "test_xarray: couple of fixes for v6-9-rc6", v2.
Here are a couple of fixes which should be merged into the queue for
v6.9-rc6. The first one was reported by Liam, after fixing that I noticed
an issue with a test, and a fix for that is in the second patch.
This patch (of 2):
Liam reported that compiling the test_xarray on userspace was broken. I
was not even aware that was possible but you can via and you can run these
tests in userspace with:
make -C tools/testing/radix-tree
./tools/testing/radix-tree/xarray
Add the two helpers we need to fix compilation. We don't need a userspace
schedule() so just make it do nothing.
Link: https://lkml.kernel.org/r/20240423192221.301095-1-mcgrof@kernel.org
Link: https://lkml.kernel.org/r/20240423192221.301095-2-mcgrof@kernel.org
Fixes: a60cc288a1 ("test_xarray: add tests for advanced multi-index use")
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
Reported-by: "Liam R. Howlett" <Liam.Howlett@oracle.com>
Cc: Daniel Gomez <da.gomez@samsung.com>
Cc: Darrick J. Wong <djwong@kernel.org>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Pankaj Raghav <p.raghav@samsung.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
With commit ea4b5b33bf ("mm,page_owner: update metadata for tail
pages"), new API __update_page_owner_handle was introduced and arguemnt
was passed in wrong order from __set_page_owner and thus page_owner is
giving wrong data.
[ 15.982420] page last allocated via order 0, migratetype Unmovable, gfp_mask 0xcc0(GFP_KERNEL), pid 80, tgid -1210279584 (insmod), ts 80, free_ts 0
Fixing the same.
Correct output:
[ 14.556482] page last allocated via order 0, migratetype Unmovable, gfp_mask 0xcc0(GFP_KERNEL), pid 80, tgid 80 (insmod), ts 14552004992, free_ts 0
Link: https://lkml.kernel.org/r/20240424111838.3782931-1-hariom1.p@samsung.com
Fixes: ea4b5b33bf ("mm,page_owner: update metadata for tail pages")
Signed-off-by: Maninder Singh <maninder1.s@samsung.com>
Signed-off-by: Hariom Panthi <hariom1.p@samsung.com>
Acked-by: Oscar Salvador <osalvador@suse.de>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Lorenzo Stoakes <lstoakes@gmail.com>
Cc: Rohit Thapliyal <r.thapliyal@samsung.com>
Cc: Uladzislau Rezki (Sony) <urezki@gmail.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Userfaultfd unregister includes a step to remove wr-protect bits from all
the relevant pgtable entries, but that only covered an explicit
UFFDIO_UNREGISTER ioctl, not a close() on the userfaultfd itself. Cover
that too. This fixes a WARN trace.
The only user visible side effect is the user can observe leftover
wr-protect bits even if the user close()ed on an userfaultfd when
releasing the last reference of it. However hopefully that should be
harmless, and nothing bad should happen even if so.
This change is now more important after the recent page-table-check
patch we merged in mm-unstable (446dd9ad37d0 ("mm/page_table_check:
support userfault wr-protect entries")), as we'll do sanity check on
uffd-wp bits without vma context. So it's better if we can 100%
guarantee no uffd-wp bit leftovers, to make sure each report will be
valid.
Link: https://lore.kernel.org/all/000000000000ca4df20616a0fe16@google.com/
Fixes: f369b07c86 ("mm/uffd: reset write protection when unregister with wp-mode")
Analyzed-by: David Hildenbrand <david@redhat.com>
Link: https://lkml.kernel.org/r/20240422133311.2987675-1-peterx@redhat.com
Reported-by: syzbot+d8426b591c36b21c750e@syzkaller.appspotmail.com
Signed-off-by: Peter Xu <peterx@redhat.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Cc: Nadav Amit <nadav.amit@gmail.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
The save/restore of nr_hugepages was added to the test itself by using the
atexit() functionality. But it is broken as parent exits after creating
child. Hence calling the atexit() function early. That's not it. The
child exits after creating its child and so on.
The parent cannot wait to get the termination status for its children as
it'll keep on holding the resources until the new pkey allocation fails.
It is impossible to wait for exits of all the grand and great grand
children. Hence the restoring of nr_hugepages value from parent is wrong.
Let's save/restore the nr_hugepages settings in the launch script
instead of doing it in the test.
Link: https://lkml.kernel.org/r/20240419115027.3848958-1-usama.anjum@collabora.com
Fixes: c52eb6db7b ("selftests: mm: restore settings from only parent process")
Signed-off-by: Muhammad Usama Anjum <usama.anjum@collabora.com>
Reported-by: Joey Gouly <joey.gouly@arm.com>
Closes: https://lore.kernel.org/all/20240418125250.GA2941398@e124191.cambridge.arm.com
Cc: Joey Gouly <joey.gouly@arm.com>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Commit 9acad7ba3e ("hugetlb: use vmf_anon_prepare() instead of
anon_vma_prepare()") may bailout after allocating a folio if we do not
hold the mmap lock. When this occurs, vmf_anon_prepare() will release the
vma lock. Hugetlb then attempts to call restore_reserve_on_error(), which
depends on the vma lock being held.
We can move vmf_anon_prepare() prior to the folio allocation in order to
avoid calling restore_reserve_on_error() without the vma lock.
Link: https://lkml.kernel.org/r/ZiFqSrSRLhIV91og@fedora
Fixes: 9acad7ba3e ("hugetlb: use vmf_anon_prepare() instead of anon_vma_prepare()")
Reported-by: syzbot+ad1b592fc4483655438b@syzkaller.appspotmail.com
Signed-off-by: Vishal Moola (Oracle) <vishal.moola@gmail.com>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
The current folio_test_hugetlb() can be fooled by a concurrent folio split
into returning true for a folio which has never belonged to hugetlbfs.
This can't happen if the caller holds a refcount on it, but we have a few
places (memory-failure, compaction, procfs) which do not and should not
take a speculative reference.
Since hugetlb pages do not use individual page mapcounts (they are always
fully mapped and use the entire_mapcount field to record the number of
mappings), the PageType field is available now that page_mapcount()
ignores the value in this field.
In compaction and with CONFIG_DEBUG_VM enabled, the current implementation
can result in an oops, as reported by Luis. This happens since 9c5ccf2db0
("mm: remove HUGETLB_PAGE_DTOR") effectively added some VM_BUG_ON() checks
in the PageHuge() testing path.
[willy@infradead.org: update vmcoreinfo]
Link: https://lkml.kernel.org/r/ZgGZUvsdhaT1Va-T@casper.infradead.org
Link: https://lkml.kernel.org/r/20240321142448.1645400-6-willy@infradead.org
Fixes: 9c5ccf2db0 ("mm: remove HUGETLB_PAGE_DTOR")
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: David Hildenbrand <david@redhat.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Reported-by: Luis Chamberlain <mcgrof@kernel.org>
Closes: https://bugzilla.kernel.org/show_bug.cgi?id=218227
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Fix the warnings by initializing and marking the variable as unused.
I've caught the warnings by using clang.
split_huge_page_test.c:303:6: warning: variable 'dummy' set but not used [-Wunused-but-set-variable]
303 | int dummy;
| ^
split_huge_page_test.c:343:3: warning: variable 'dummy' is uninitialized when used here [-Wuninitialized]
343 | dummy += *(*addr + i);
| ^~~~~
split_huge_page_test.c:303:11: note: initialize the variable 'dummy' to silence this warning
303 | int dummy;
| ^
| = 0
2 warnings generated.
Link: https://lkml.kernel.org/r/20240416162658.3353622-1-usama.anjum@collabora.com
Fixes: fc4d182316 ("mm: huge_memory: enable debugfs to split huge pages to any order")
Signed-off-by: Muhammad Usama Anjum <usama.anjum@collabora.com>
Reviewed-by: Zi Yan <ziy@nvidia.com>
Cc: Bill Wendling <morbo@google.com>
Cc: Justin Stitt <justinstitt@google.com>
Cc: Muhammad Usama Anjum <usama.anjum@collabora.com>
Cc: Nathan Chancellor <nathan@kernel.org>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
The size of the nilfs_type_by_mode array in the fs/nilfs2/dir.c file is
defined as "S_IFMT >> S_SHIFT", but the nilfs_set_de_type() function,
which uses this array, specifies the index to read from the array in the
same way as "(mode & S_IFMT) >> S_SHIFT".
static void nilfs_set_de_type(struct nilfs_dir_entry *de, struct inode
*inode)
{
umode_t mode = inode->i_mode;
de->file_type = nilfs_type_by_mode[(mode & S_IFMT)>>S_SHIFT]; // oob
}
However, when the index is determined this way, an out-of-bounds (OOB)
error occurs by referring to an index that is 1 larger than the array size
when the condition "mode & S_IFMT == S_IFMT" is satisfied. Therefore, a
patch to resize the nilfs_type_by_mode array should be applied to prevent
OOB errors.
Link: https://lkml.kernel.org/r/20240415182048.7144-1-konishi.ryusuke@gmail.com
Reported-by: syzbot+2e22057de05b9f3b30d8@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=2e22057de05b9f3b30d8
Fixes: 2ba466d74e ("nilfs2: directory entry operations")
Signed-off-by: Jeongjun Park <aha310510@gmail.com>
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Tested-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
In order to minimize code size (CONFIG_CC_OPTIMIZE_FOR_SIZE=y),
compiler might choose to make a regular function call (out-of-line) for
shmem_is_huge() instead of inlining it. When transparent hugepages are
disabled (CONFIG_TRANSPARENT_HUGEPAGE=n), it can cause compilation
error.
mm/shmem.c: In function `shmem_getattr':
./include/linux/huge_mm.h:383:27: note: in expansion of macro `BUILD_BUG'
383 | #define HPAGE_PMD_SIZE ({ BUILD_BUG(); 0; })
| ^~~~~~~~~
mm/shmem.c:1148:33: note: in expansion of macro `HPAGE_PMD_SIZE'
1148 | stat->blksize = HPAGE_PMD_SIZE;
To prevent the possible error, always inline shmem_is_huge() when
transparent hugepages are disabled.
Link: https://lkml.kernel.org/r/20240409155407.2322714-1-sumanthk@linux.ibm.com
Signed-off-by: Sumanth Korikkar <sumanthk@linux.ibm.com>
Acked-by: David Hildenbrand <david@redhat.com>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Ilya Leoshkevich <iii@linux.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Kefeng Wang reported that he was seeing some memory leaks with kmemleak
with page_owner enabled.
The reason is that we enable the page_owner_inited static branch and then
proceed with the linking of stack_list struct to dummy_stack, which means
that exists a race window between these two steps where we can have pages
already being allocated calling add_stack_record_to_list(), allocating
objects and linking them to stack_list, but then we set stack_list
pointing to dummy_stack in init_page_owner. Which means that the objects
that have been allocated during that time window are unreferenced and
lost.
Fix this by deferring the enablement of the branch until we have properly
set up the list.
Link: https://lkml.kernel.org/r/20240409131715.13632-1-osalvador@suse.de
Fixes: 4bedfb314b ("mm,page_owner: maintain own list of stack_records structs")
Signed-off-by: Oscar Salvador <osalvador@suse.de>
Reported-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Closes: https://lore.kernel.org/linux-mm/74b147b0-718d-4d50-be75-d6afc801cd24@huawei.com/
Tested-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Syskiller has produced an out of bounds access in fill_meta_index().
That out of bounds access is ultimately caused because the inode
has an inode number with the invalid value of zero, which was not checked.
The reason this causes the out of bounds access is due to following
sequence of events:
1. Fill_meta_index() is called to allocate (via empty_meta_index())
and fill a metadata index. It however suffers a data read error
and aborts, invalidating the newly returned empty metadata index.
It does this by setting the inode number of the index to zero,
which means unused (zero is not a valid inode number).
2. When fill_meta_index() is subsequently called again on another
read operation, locate_meta_index() returns the previous index
because it matches the inode number of 0. Because this index
has been returned it is expected to have been filled, and because
it hasn't been, an out of bounds access is performed.
This patch adds a sanity check which checks that the inode number
is not zero when the inode is created and returns -EINVAL if it is.
[phillip@squashfs.org.uk: whitespace fix]
Link: https://lkml.kernel.org/r/20240409204723.446925-1-phillip@squashfs.org.uk
Link: https://lkml.kernel.org/r/20240408220206.435788-1-phillip@squashfs.org.uk
Signed-off-by: Phillip Lougher <phillip@squashfs.org.uk>
Reported-by: "Ubisectech Sirius" <bugreport@ubisectech.com>
Closes: https://lore.kernel.org/lkml/87f5c007-b8a5-41ae-8b57-431e924c5915.bugreport@ubisectech.com/
Cc: Christian Brauner <brauner@kernel.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Tony reported that the Machine check recovery was broken in v6.9-rc1, as
he was hitting a VM_BUG_ON when injecting uncorrectable memory errors to
DRAM.
After some more digging and debugging on his side, he realized that this
went back to v6.1, with the introduction of 'commit 0d206b5d2e
("mm/swap: add swp_offset_pfn() to fetch PFN from swap entry")'. That
commit, among other things, introduced swp_offset_pfn(), replacing
hwpoison_entry_to_pfn() in its favour.
The patch also introduced a VM_BUG_ON() check for is_pfn_swap_entry(), but
is_pfn_swap_entry() never got updated to cover hwpoison entries, which
means that we would hit the VM_BUG_ON whenever we would call
swp_offset_pfn() for such entries on environments with CONFIG_DEBUG_VM
set. Fix this by updating the check to cover hwpoison entries as well,
and update the comment while we are it.
Link: https://lkml.kernel.org/r/20240407130537.16977-1-osalvador@suse.de
Fixes: 0d206b5d2e ("mm/swap: add swp_offset_pfn() to fetch PFN from swap entry")
Signed-off-by: Oscar Salvador <osalvador@suse.de>
Reported-by: Tony Luck <tony.luck@intel.com>
Closes: https://lore.kernel.org/all/Zg8kLSl2yAlA3o5D@agluck-desk3/
Tested-by: Tony Luck <tony.luck@intel.com>
Reviewed-by: Peter Xu <peterx@redhat.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Acked-by: Miaohe Lin <linmiaohe@huawei.com>
Cc: <stable@vger.kernel.org> [6.1.x]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
After UFFDIO_POISON, there can be two kinds of hugetlb pte markers, either
the POISON one or UFFD_WP one.
Allow change protection to run on a poisoned marker just like !hugetlb
cases, ignoring the marker irrelevant of the permission.
Here the two bits are mutual exclusive. For example, when install a
poisoned entry it must not be UFFD_WP already (by checking pte_none()
before such install). And it also means if UFFD_WP is set there must have
no POISON bit set. It makes sense because UFFD_WP is a bit to reflect
permission, and permissions do not apply if the pte is poisoned and
destined to sigbus.
So here we simply check uffd_wp bit set first, do nothing otherwise.
Attach the Fixes to UFFDIO_POISON work, as before that it should not be
possible to have poison entry for hugetlb (e.g., hugetlb doesn't do swap,
so no chance of swapin errors).
Link: https://lkml.kernel.org/r/20240405231920.1772199-1-peterx@redhat.com
Link: https://lore.kernel.org/r/000000000000920d5e0615602dd1@google.com
Fixes: fc71884a5f ("mm: userfaultfd: add new UFFDIO_POISON ioctl")
Signed-off-by: Peter Xu <peterx@redhat.com>
Reported-by: syzbot+b07c8ac8eee3d4d8440f@syzkaller.appspotmail.com
Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Axel Rasmussen <axelrasmussen@google.com>
Cc: <stable@vger.kernel.org> [6.6+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
When seq_* code sees that its buffer overflowed, it re-allocates a bigger
onecand calls seq_operations->start() callback again. stack_start()
naively though that if it got called again, it meant that the old record
got already printed so it returned the next object, but that is not true.
The consequence of that is that every time stack_stop() -> stack_start()
get called because we needed a bigger buffer, stack_start() will skip
entries, and those will not be printed.
Fix it by not advancing to the next object in stack_start().
Link: https://lkml.kernel.org/r/20240404070702.2744-5-osalvador@suse.de
Fixes: 765973a098 ("mm,page_owner: display all stacks and their count")
Signed-off-by: Oscar Salvador <osalvador@suse.de>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Alexander Potapenko <glider@google.com>
Cc: Alexandre Ghiti <alexghiti@rivosinc.com>
Cc: Andrey Konovalov <andreyknvl@gmail.com>
Cc: Marco Elver <elver@google.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Upon migration, new allocated pages are being given the handle of the old
pages. This is problematic because it means that for the stack which
allocated the old page, we will be substracting the old page + the new one
when that page is freed, creating an accounting imbalance.
There is an interest in keeping it that way, as otherwise the output will
biased towards migration stacks should those operations occur often, but
that is not really helpful.
The link from the new page to the old stack is being performed by calling
__update_page_owner_handle() in __folio_copy_owner(). The only thing that
is left is to link the migrate stack to the old page, so the old page will
be subtracted from the migrate stack, avoiding by doing so any possible
imbalance.
Link: https://lkml.kernel.org/r/20240404070702.2744-4-osalvador@suse.de
Fixes: 217b2119b9 ("mm,page_owner: implement the tracking of the stacks count")
Signed-off-by: Oscar Salvador <osalvador@suse.de>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Alexander Potapenko <glider@google.com>
Cc: Alexandre Ghiti <alexghiti@rivosinc.com>
Cc: Andrey Konovalov <andreyknvl@gmail.com>
Cc: Marco Elver <elver@google.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Patch series "page_owner: Fix refcount imbalance and print fixup", v4.
This series consists of a refactoring/correctness of updating the metadata
of tail pages, a couple of fixups for the refcounting part and a fixup for
the stack_start() function.
From this series on, instead of counting the stacks, we count the
outstanding nr_base_pages each stack has, which gives us a much better
memory overview. The other fixup is for the migration part.
A more detailed explanation can be found in the changelog of the
respective patches.
This patch (of 4):
__set_page_owner_handle() and __reset_page_owner() update the metadata of
all pages when the page is of a higher-order, but we miss to do the same
when the pages are migrated. __folio_copy_owner() only updates the
metadata of the head page, meaning that the information stored in the
first page and the tail pages will not match.
Strictly speaking that is not a big problem because 1) we do not print
tail pages and 2) upon splitting all tail pages will inherit the metadata
of the head page, but it is better to have all metadata in check should
there be any problem, so it can ease debugging.
For that purpose, a couple of helpers are created
__update_page_owner_handle() which updates the metadata on allocation, and
__update_page_owner_free_handle() which does the same when the page is
freed.
__folio_copy_owner() will make use of both as it needs to entirely replace
the page_owner metadata for the new page.
Link: https://lkml.kernel.org/r/20240404070702.2744-1-osalvador@suse.de
Link: https://lkml.kernel.org/r/20240404070702.2744-2-osalvador@suse.de
Signed-off-by: Oscar Salvador <osalvador@suse.de>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Tested-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Alexandre Ghiti <alexghiti@rivosinc.com>
Cc: Andrey Konovalov <andreyknvl@gmail.com>
Cc: Marco Elver <elver@google.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Alexandre Ghiti <alexghiti@rivosinc.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Darrick reports that in some cases where pread() would fail with -EIO and
mmap()+access would generate a SIGBUS signal, MADV_POPULATE_READ /
MADV_POPULATE_WRITE will keep retrying forever and not fail with -EFAULT.
While the madvise() call can be interrupted by a signal, this is not the
desired behavior. MADV_POPULATE_READ / MADV_POPULATE_WRITE should behave
like page faults in that case: fail and not retry forever.
A reproducer can be found at [1].
The reason is that __get_user_pages(), as called by
faultin_vma_page_range(), will not handle VM_FAULT_RETRY in a proper way:
it will simply return 0 when VM_FAULT_RETRY happened, making
madvise_populate()->faultin_vma_page_range() retry again and again, never
setting FOLL_TRIED->FAULT_FLAG_TRIED for __get_user_pages().
__get_user_pages_locked() does what we want, but duplicating that logic in
faultin_vma_page_range() feels wrong.
So let's use __get_user_pages_locked() instead, that will detect
VM_FAULT_RETRY and set FOLL_TRIED when retrying, making the fault handler
return VM_FAULT_SIGBUS (VM_FAULT_ERROR) at some point, propagating -EFAULT
from faultin_page() to __get_user_pages(), all the way to
madvise_populate().
But, there is an issue: __get_user_pages_locked() will end up re-taking
the MM lock and then __get_user_pages() will do another VMA lookup. In
the meantime, the VMA layout could have changed and we'd fail with
different error codes than we'd want to.
As __get_user_pages() will currently do a new VMA lookup either way, let
it do the VMA handling in a different way, controlled by a new
FOLL_MADV_POPULATE flag, effectively moving these checks from
madvise_populate() + faultin_page_range() in there.
With this change, Darricks reproducer properly fails with -EFAULT, as
documented for MADV_POPULATE_READ / MADV_POPULATE_WRITE.
[1] https://lore.kernel.org/all/20240313171936.GN1927156@frogsfrogsfrogs/
Link: https://lkml.kernel.org/r/20240314161300.382526-1-david@redhat.com
Link: https://lkml.kernel.org/r/20240314161300.382526-2-david@redhat.com
Fixes: 4ca9b3859d ("mm/madvise: introduce MADV_POPULATE_(READ|WRITE) to prefault page tables")
Signed-off-by: David Hildenbrand <david@redhat.com>
Reported-by: Darrick J. Wong <djwong@kernel.org>
Closes: https://lore.kernel.org/all/20240311223815.GW1927156@frogsfrogsfrogs/
Cc: Darrick J. Wong <djwong@kernel.org>
Cc: Hugh Dickins <hughd@google.com>
Cc: Jason Gunthorpe <jgg@nvidia.com>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Pull sysfs fix from Al Viro:
"Get rid of lockdep false positives around sysfs/overlayfs
syzbot has uncovered a class of lockdep false positives for setups
with sysfs being one of the backing layers in overlayfs. The root
cause is that of->mutex allocated when opening a sysfs file read-only
(which overlayfs might do) is confused with of->mutex of a file opened
writable (held in write to sysfs file, which overlayfs won't do).
Assigning them separate lockdep classes fixes that bunch and it's
obviously safe"
* tag 'pull-sysfs-annotation-fix' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
kernfs: annotate different lockdep class for of->mutex of writable files
Pull misc x86 fixes from Ingo Molnar:
- Follow up fixes for the BHI mitigations code
- Fix !SPECULATION_MITIGATIONS bug not turning off mitigations as
expected
- Work around an APIC emulation bug when the kernel is built with Clang
and run as a SEV guest
- Follow up x86 topology fixes
* tag 'x86-urgent-2024-04-14' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/cpu/amd: Move TOPOEXT enablement into the topology parser
x86/cpu/amd: Make the NODEID_MSR union actually work
x86/cpu/amd: Make the CPUID 0x80000008 parser correct
x86/bugs: Replace CONFIG_SPECTRE_BHI_{ON,OFF} with CONFIG_MITIGATION_SPECTRE_BHI
x86/bugs: Remove CONFIG_BHI_MITIGATION_AUTO and spectre_bhi=auto
x86/bugs: Clarify that syscall hardening isn't a BHI mitigation
x86/bugs: Fix BHI handling of RRSBA
x86/bugs: Rename various 'ia32_cap' variables to 'x86_arch_cap_msr'
x86/bugs: Cache the value of MSR_IA32_ARCH_CAPABILITIES
x86/bugs: Fix BHI documentation
x86/cpu: Actually turn off mitigations by default for SPECULATION_MITIGATIONS=n
x86/topology: Don't update cpu_possible_map in topo_set_cpuids()
x86/bugs: Fix return type of spectre_bhi_state()
x86/apic: Force native_apic_mem_read() to use the MOV instruction
Pull perf event fix from Ingo Molnar:
"Fix the x86 PMU multi-counter code returning invalid data in certain
circumstances"
* tag 'perf-urgent-2024-04-14' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
perf/x86: Fix out of range data
Pull locking fix from Ingo Molnar:
"Fix a PREEMPT_RT build bug"
* tag 'locking-urgent-2024-04-14' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
locking: Make rwsem_assert_held_write_nolockdep() build with PREEMPT_RT=y
Pull irq fix from Ingo Molnar:
"Fix a bug in the GIC irqchip driver"
* tag 'irq-urgent-2024-04-14' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
irqchip/gic-v3-its: Fix VSYNC referencing an unmapped VPE on GIC v4.1
Pull virtio bugfixes from Michael Tsirkin:
"Some small, obvious (in hindsight) bugfixes:
- new ioctl in vhost-vdpa has a wrong # - not too late to fix
- vhost has apparently been lacking an smp_rmb() - due to code
duplication :( The duplication will be fixed in the next merge
cycle, this is a minimal fix
- an error message in vhost talks about guest moving used index -
which of course never happens, guest only ever moves the available
index
- i2c-virtio didn't set the driver owner so it did not get refcounted
correctly"
* tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost:
vhost: correct misleading printing information
vhost-vdpa: change ioctl # for VDPA_GET_VRING_SIZE
virtio: store owner from modules with register_virtio_driver()
vhost: Add smp_rmb() in vhost_enable_notify()
vhost: Add smp_rmb() in vhost_vq_avail_empty()
Pull dma-mapping fixes from Christoph Hellwig:
- fix up swiotlb buffer padding even more (Petr Tesarik)
- fix for partial dma_sync on swiotlb (Michael Kelley)
- swiotlb debugfs fix (Dexuan Cui)
* tag 'dma-maping-6.9-2024-04-14' of git://git.infradead.org/users/hch/dma-mapping:
swiotlb: do not set total_used to 0 in swiotlb_create_debugfs_files()
swiotlb: fix swiotlb_bounce() to do partial sync's correctly
swiotlb: extend buffer pre-padding to alloc_align_mask if necessary
The writable file /sys/power/resume may call vfs lookup helpers for
arbitrary paths and readonly files can be read by overlayfs from vfs
helpers when sysfs is a lower layer of overalyfs.
To avoid a lockdep warning of circular dependency between overlayfs
inode lock and kernfs of->mutex, use a different lockdep class for
writable and readonly kernfs files.
Reported-by: syzbot+9a5b0ced8b1bfb238b56@syzkaller.appspotmail.com
Fixes: 0fedefd4c4 ("kernfs: sysfs: support custom llseek method for sysfs entries")
Suggested-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Pull ata fixes from Damien Le Moal:
- Add the mask_port_map parameter to the ahci driver. This is a
follow-up to the recent snafu with the ASMedia controller and its
virtual port hidding port-multiplier devices. As ASMedia confirmed
that there is no way to determine if these slow-to-probe virtual
ports are actually representing the ports of a port-multiplier
devices, this new parameter allow masking ports to significantly
speed up probing during system boot, resulting in shorter boot times.
- A fix for an incorrect handling of a port unlock in
ata_scsi_dev_rescan().
- Allow command duration limits to be detected for ACS-4 devices are
there are such devices out in the field.
* tag 'ata-6.9-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/libata/linux:
ata: libata-core: Allow command duration limits detection for ACS-4 drives
ata: libata-scsi: Fix ata_scsi_dev_rescan() error path
ata: ahci: Add mask_port_map module parameter
Tiezhu Yang
Christoph Hellwig
Ryan Roberts
Hailong.Liu
Kefeng Wang
Alexander Potapenko
Luis Chamberlain
Jarkko Sakkinen
Maninder Singh
Liam R. Howlett
Peter Xu
Miaohe Lin
Muhammad Usama Anjum
Andrey Ryabinin
Vishal Moola (Oracle)
Johannes Weiner
Matthew Wilcox (Oracle)
Edward Liaw
Jeongjun Park
Naoya Horiguchi
Sumanth Korikkar
Oscar Salvador
Phillip Lougher
Lokesh Gidra
David Hildenbrand
Linus Torvalds
Amir Goldstein