Peter Xu [Thu, 20 Oct 2022 19:38:32 +0000 (15:38 -0400)]
mm/hugetlb: unify clearing of RestoreReserve for private pages
A trivial cleanup to move clearing of RestoreReserve into adding anon rmap
of private hugetlb mappings. It matches with the shared mappings where we
only clear the bit when adding into page cache, rather than spreading it
around the code paths.
mm: convert find_get_incore_page() to filemap_get_incore_folio()
Return the containing folio instead of the precise page. One of the
callers wants the folio and the other can do the folio->page conversion
itself. Nets 442 bytes of text size reduction, 478 bytes removed and 36
bytes added.
Kefeng Wang [Tue, 18 Oct 2022 07:40:14 +0000 (15:40 +0800)]
mm: remove kern_addr_valid() completely
Most architectures (except arm64/x86/sparc) simply return 1 for
kern_addr_valid(), which is only used in read_kcore(), and it calls
copy_from_kernel_nofault() which could check whether the address is a
valid kernel address. So as there is no need for kern_addr_valid(), let's
remove it.
Patch series "Add basic trace events for vmap/vmalloc (v2)", v2.
This small series add some basic trace events for the vmap/vmalloc code.
Since currently we lack any, sometimes it is hard to start debuging vmap
code if an issue is reported or occured.
For example https://lore.kernel.org/linux-mm/Y0p8BZIiDXLQbde%2F@pc636/T/
The final patch adds two reviewers for vmalloc code.
This patch (of 7):
It is for debug purposes and for validation of passed parameters.
Liu Shixin [Fri, 23 Sep 2022 03:33:47 +0000 (11:33 +0800)]
memory: move hotplug memory notifier priority to same file for easy sorting
The priority of hotplug memory callback is defined in a different file.
And there are some callers using numbers directly. Collect them together
into include/linux/memory.h for easy reading. This allows us to sort
their priorities more intuitively without additional comments.
Liu Shixin [Fri, 23 Sep 2022 03:33:45 +0000 (11:33 +0800)]
ACPI: HMAT: use hotplug_memory_notifier() directly
Commit 76ae847497bc52 ("Documentation: raise minimum supported version of
GCC to 5.1") updated the minimum gcc version to 5.1. So the problem
mentioned in f02c69680088 ("include/linux/memory.h: implement
register_hotmemory_notifier()") no longer exist. So we can now switch to
use hotplug_memory_notifier() directly rather than
register_hotmemory_notifier().
Liu Shixin [Fri, 23 Sep 2022 03:33:44 +0000 (11:33 +0800)]
mm/mm_init.c: use hotplug_memory_notifier() directly
Commit 76ae847497bc52 ("Documentation: raise minimum supported version of
GCC to 5.1") updated the minimum gcc version to 5.1. So the problem
mentioned in f02c69680088 ("include/linux/memory.h: implement
register_hotmemory_notifier()") no longer exist. So we can now switch to
use hotplug_memory_notifier() directly rather than
register_hotmemory_notifier().
Liu Shixin [Fri, 23 Sep 2022 03:33:43 +0000 (11:33 +0800)]
mm/mmap: use hotplug_memory_notifier() directly
Commit 76ae847497bc52 ("Documentation: raise minimum supported version of
GCC to 5.1") updated the minimum gcc version to 5.1. So the problem
mentioned in f02c69680088 ("include/linux/memory.h: implement
register_hotmemory_notifier()") no longer exist. So we can now switch to
use hotplug_memory_notifier() directly rather than
register_hotmemory_notifier().
Liu Shixin [Fri, 23 Sep 2022 03:33:42 +0000 (11:33 +0800)]
mm/slub.c: use hotplug_memory_notifier() directly
Commit 76ae847497bc52 ("Documentation: raise minimum supported version of
GCC to 5.1") updated the minimum gcc version to 5.1. So the problem
mentioned in f02c69680088 ("include/linux/memory.h: implement
register_hotmemory_notifier()") no longer exist. So we can now switch to
use hotplug_memory_notifier() directly rather than
register_hotmemory_notifier().
Liu Shixin [Fri, 23 Sep 2022 03:33:41 +0000 (11:33 +0800)]
fs/proc/kcore.c: use hotplug_memory_notifier() directly
Commit 76ae847497bc52 ("Documentation: raise minimum supported version of
GCC to 5.1") updated the minimum gcc version to 5.1. So the problem
mentioned in f02c69680088 ("include/linux/memory.h: implement
register_hotmemory_notifier()") no longer exist. So we can now switch to
use hotplug_memory_notifier() directly rather than
register_hotmemory_notifier().
Liu Shixin [Fri, 23 Sep 2022 03:33:40 +0000 (11:33 +0800)]
cgroup/cpuset: use hotplug_memory_notifier() directly
Patch series "mm: Use hotplug_memory_notifier() instead of
register_hotmemory_notifier()", v4.
Commit f02c69680088 ("include/linux/memory.h: implement
register_hotmemory_notifier()") introduced register_hotmemory_notifier()
to avoid a compile problem with gcc-4.4.4:
When CONFIG_MEMORY_HOTPLUG=n, we don't want the memory-hotplug notifier
handlers to be included in the .o files, for space reasons.
The existing hotplug_memory_notifier() tries to handle this but testing
with gcc-4.4.4 shows that it doesn't work - the hotplug functions are
still present in the .o files.
Since commit 76ae847497bc52 ("Documentation: raise minimum supported
version of GCC to 5.1") has already updated the minimum gcc version to
5.1. The previous problem mentioned in f02c69680088 does not exist. So
we can now revert to use hotplug_memory_notifier() directly rather than
register_hotmemory_notifier().
In the last patch, we move all hotplug memory notifier priority to same
file for easy sorting.
This patch (of 8):
Commit 76ae847497bc52 ("Documentation: raise minimum supported version of
GCC to 5.1") updated the minimum gcc version to 5.1. So the problem
mentioned in f02c69680088 ("include/linux/memory.h: implement
register_hotmemory_notifier()") no longer exist. So we can now switch to
use hotplug_memory_notifier() directly rather than
register_hotmemory_notifier().
selftests/vm: anon_cow: add R/O longterm tests via gup_test
Let's trigger a R/O longterm pin on three cases of R/O mapped anonymous
pages:
* exclusive (never shared)
* shared (child still alive)
* previously shared (child no longer alive)
... and make sure that the pin is reliable: whatever we write via the page
tables has to be observable via the pin.
mm/gup_test: start/stop/read functionality for PIN LONGTERM test
We want an easy way to take a R/O or R/W longterm pin on a range and be
able to observe the content of the pinned pages, so we can properly test
how longterm puns interact with our COW logic.
io_uring provides a simple mechanism to test long-term, R/W GUP pins
-- via fixed buffers -- and can be used to verify that GUP pins stay
in sync with the pages in the page table even if a page would
temporarily get mapped R/O or concurrent fork() could accidentially
end up sharing pinned pages with the child.
Note that this essentially re-introduces local_config support that was
removed recently in commit 6f83d6c74ea5 ("Kselftests: remove support of
libhugetlbfs from kselftests").
Let's run all existing test cases with all hugetlb sizes we're able to
detect.
Note that some tests cases still fail. This will, for example, be fixed
once vmsplice properly uses FOLL_PIN instead of FOLL_GET for pinning.
With 2 MiB and 1 GiB hugetlb on x86_64, the expected failures are:
# [RUN] vmsplice() + unmap in child ... with hugetlb (2048 kB)
not ok 23 No leak from parent into child
# [RUN] vmsplice() + unmap in child ... with hugetlb (1048576 kB)
not ok 24 No leak from parent into child
# [RUN] vmsplice() before fork(), unmap in parent after fork() ... with hugetlb (2048 kB)
not ok 35 No leak from child into parent
# [RUN] vmsplice() before fork(), unmap in parent after fork() ... with hugetlb (1048576 kB)
not ok 36 No leak from child into parent
# [RUN] vmsplice() + unmap in parent after fork() ... with hugetlb (2048 kB)
not ok 47 No leak from child into parent
# [RUN] vmsplice() + unmap in parent after fork() ... with hugetlb (1048576 kB)
not ok 48 No leak from child into parent
selftests/vm: anon_cow: test COW handling of anonymous memory
Patch series "selftests/vm: test COW handling of anonymous memory".
This is my current set of tests for testing COW handling of anonymous
memory, especially when interacting with GUP. I developed these tests
while working on PageAnonExclusive and managed to clean them up just now.
On current upstream Linux, all tests pass except the hugetlb tests that
rely on vmsplice -- these tests should pass as soon as vmsplice properly
uses FOLL_PIN instead of FOLL_GET.
I'm working on additional tests for COW handling in private mappings,
focusing on long-term R/O pinning e.g., of the shared zeropage, pagecache
pages and KSM pages. These tests, however, will go into a different file.
So this is everything I have regarding tests for anonymous memory.
This patch (of 7):
Let's start adding tests for our COW handling of anonymous memory. We'll
focus on basic tests that we can achieve without additional libraries or
gup_test extensions.
Migrate the workqueue_uaf test to the KUnit framework.
Initially, this test was intended to check that Generic KASAN prints
auxiliary stack traces for workqueues. Nevertheless, the test is enabled
for all modes to make that KASAN reports bad accesses in the tested
scenario.
The presence of auxiliary stack traces for the Generic mode needs to be
inspected manually.
Migrate the kasan_rcu_uaf test to the KUnit framework.
Changes to the implementation of the test:
- Call rcu_barrier() after call_rcu() to make that the RCU callbacks get
triggered before the test is over.
- Cast pointer passed to rcu_dereference_protected as __rcu to get rid of
the Sparse warning.
- Check that KASAN prints a report via KUNIT_EXPECT_KASAN_FAIL.
Initially, this test was intended to check that Generic KASAN prints
auxiliary stack traces for RCU objects. Nevertheless, the test is enabled
for all modes to make that KASAN reports bad accesses in RCU callbacks.
The presence of auxiliary stack traces for the Generic mode needs to be
inspected manually.
Switch KUnit-compatible KASAN tests from using per-task KUnit resources to
console tracepoints.
This allows for two things:
1. Migrating tests that trigger a KASAN report in the context of a task
other than current to KUnit framework.
This is implemented in the patches that follow.
2. Parsing and matching the contents of KASAN reports.
This is not yet implemented.
Thomas Weißschuh [Wed, 28 Sep 2022 10:45:35 +0000 (12:45 +0200)]
tmpfs: ensure O_LARGEFILE with generic_file_open()
Without this check open() will open large files on tmpfs although
O_LARGEFILE was not specified. This is inconsistent with other
filesystems. Also it will later result in EOVERFLOW on stat() or EFBIG on
write().
Lukas Bulwahn [Fri, 7 Oct 2022 08:50:27 +0000 (10:50 +0200)]
mm/shmem: remove unneeded assignments in shmem_get_folio_gfp()
After the rework of shmem_get_folio_gfp() to use a folio, the local
variable hindex is only needed to be set once before passing it to
shmem_add_to_page_cache().
Remove the unneeded initialization and assignments of the variable hindex
before the actual effective assignment and first use.
Uros Bizjak [Tue, 18 Oct 2022 14:51:54 +0000 (16:51 +0200)]
zram: use try_cmpxchg in update_used_max
Use try_cmpxchg instead of cmpxchg (*ptr, old, new) == old in
update_used_max. x86 CMPXCHG instruction returns success in ZF flag, so
this change saves a compare after cmpxchg (and related move instruction in
front of cmpxchg).
Also, reorder code a bit to remove additional compare and conditional jump
from the assembly code. Together, hese two changes save 15 bytes from the
function when compiled for x86_64.
filemap: find_get_entries() now updates start offset
Initially, find_get_entries() was being passed in the start offset as a
value. That left the calculation of the offset to the callers. This led
to complexity in the callers trying to keep track of the index.
Now find_get_entries() takes in a pointer to the start offset and updates
the value to be directly after the last entry found. If no entry is
found, the offset is not changed. This gets rid of multiple hacky
calculations that kept track of the start offset.
filemap: find_lock_entries() now updates start offset
Patch series "Rework find_get_entries() and find_lock_entries()", v3.
Originally the callers of find_get_entries() and find_lock_entries() were
keeping track of the start index themselves as they traverse the search
range.
This resulted in hacky code such as in shmem_undo_range():
index = folio->index + folio_nr_pages(folio) - 1;
where the - 1 is only present to stay in the right spot after incrementing
index later. This sort of calculation was also being done on every folio
despite not even using index later within that function.
These patches change find_get_entries() and find_lock_entries() to
calculate the new index instead of leaving it to the callers so we can
avoid all these complications.
This patch (of 2):
Initially, find_lock_entries() was being passed in the start offset as a
value. That left the calculation of the offset to the callers. This led
to complexity in the callers trying to keep track of the index.
Now find_lock_entries() takes in a pointer to the start offset and updates
the value to be directly after the last entry found. If no entry is
found, the offset is not changed. This gets rid of multiple hacky
calculations that kept track of the start offset.
Ma Wupeng [Fri, 14 Oct 2022 01:39:31 +0000 (09:39 +0800)]
mm/rmap: fix comment in anon_vma_clone()
Commit 2555283eb40d ("mm/rmap: Fix anon_vma->degree ambiguity leading to
double-reuse") use num_children and num_active_vmas to replace the origin
degree to fix anon_vma UAF problem. Update the comment in anon_vma_clone
to fit this change.
mm: add private field of first tail to struct page and struct folio
Allow struct folio to store hugetlb metadata that is contained in the
private field of the first tail page. On 32-bit, _private_1 aligns with
page[1].private.
mm/hugetlb: add folio support to hugetlb specific flag macros
Patch series "begin converting hugetlb code to folios", v4.
This patch series starts the conversion of the hugetlb code to operate on
struct folios rather than struct pages. This removes the ambiguitiy of
whether functions are operating on head pages, tail pages of compound
pages, or base pages.
This series passes the linux test project hugetlb test cases.
Patch 1 adds hugeltb specific page macros that can operate on folios.
Patch 2 adds the private field of the first tail page to struct page. For
32-bit, _private_1 alinging with page[1].private was confirmed by using
pahole.
Patch 3 introduces hugetlb subpool helper functions which operate on
struct folios. These patches were tested using the hugepage-mmap.c
selftest along with the migratepages command.
Patch 4 converts hugetlb_delete_from_page_cache() to use folios.
Patch 5 adds a folio_hstate() function to get hstate information from a
folio and adds a user of folio_hstate().
Bpftrace was used to track time spent in the free_huge_pages function
during the ltp test cases as it is a caller of the hugetlb subpool
functions. From the histogram, the performance is similar before and
after the patch series.
Allow the macros which test, set, and clear hugetlb specific page flags to
take a hugetlb folio as an input. The macrros are generated as
folio_{test, set, clear}_hugetlb_{restore_reserve, migratable, temporary,
freed, vmemmap_optimized, raw_hwp_unreliable}.
Peter Xu [Fri, 14 Oct 2022 14:40:15 +0000 (10:40 -0400)]
selftests/vm: drop mnt point for hugetlb in run_vmtests.sh
After converting all the three relevant testcases (uffd, madvise, mremap)
to use memfd, no test will need the hugetlb mount point anymore. Drop the
code.
Peter Xu [Fri, 14 Oct 2022 14:39:18 +0000 (10:39 -0400)]
selftests/vm: use memfd for uffd hugetlb tests
Patch series "selftests/vm: Drop hugetlb mntpoint in run_vmtests.sh", v2.
Clean the code up so we can use the same memfd for both hugetlb and shmem
which is cleaner.
This patch (of 4):
We already used memfd for shmem test, move it forward with hugetlb too so
that we don't need user to specify the hugetlb file path explicitly when
running hugetlb shared tests.
Johannes Weiner [Thu, 13 Oct 2022 19:31:13 +0000 (15:31 -0400)]
mm: vmscan: make rotations a secondary factor in balancing anon vs file
We noticed a 2% webserver throughput regression after upgrading from 5.6.
This could be tracked down to a shift in the anon/file reclaim balance
(confirmed with swappiness) that resulted in worse reclaim efficiency and
thus more kswapd activity for the same outcome.
The change that exposed the problem is aae466b0052e ("mm/swap: implement
workingset detection for anonymous LRU"). By qualifying swapins based on
their refault distance, it lowered the cost of anon reclaim in this
workload, in turn causing (much) more anon scanning than before. Scanning
the anon list is more expensive due to the higher ratio of mmapped pages
that may rotate during reclaim, and so the result was an increase in %sys
time.
Right now, rotations aren't considered a cost when balancing scan pressure
between LRUs. We can end up with very few file refaults putting all the
scan pressure on hot anon pages that are rotated en masse, don't get
reclaimed, and never push back on the file LRU again. We still only
reclaim file cache in that case, but we burn a lot CPU rotating anon
pages. It's "fair" from an LRU age POV, but doesn't reflect the real cost
it imposes on the system.
Consider rotations as a secondary factor in balancing the LRUs. This
doesn't attempt to make a precise comparison between IO cost and CPU cost,
it just says: if reloads are about comparable between the lists, or
rotations are overwhelmingly different, adjust for CPU work.
This fixed the regression on our webservers. It has since been deployed
to the entire Meta fleet and hasn't caused any problems.
Mike Kravetz [Mon, 19 Sep 2022 02:13:48 +0000 (19:13 -0700)]
hugetlb: simplify hugetlb handling in follow_page_mask
During discussions of this series [1], it was suggested that hugetlb
handling code in follow_page_mask could be simplified. At the beginning
of follow_page_mask, there currently is a call to follow_huge_addr which
'may' handle hugetlb pages. ia64 is the only architecture which provides
a follow_huge_addr routine that does not return error. Instead, at each
level of the page table a check is made for a hugetlb entry. If a hugetlb
entry is found, a call to a routine associated with that entry is made.
Currently, there are two checks for hugetlb entries at each page table
level. The first check is of the form:
if (p?d_huge())
page = follow_huge_p?d();
the second check is of the form:
if (is_hugepd())
page = follow_huge_pd().
We can replace these checks, as well as the special handling routines such
as follow_huge_p?d() and follow_huge_pd() with a single routine to handle
hugetlb vmas.
A new routine hugetlb_follow_page_mask is called for hugetlb vmas at the
beginning of follow_page_mask. hugetlb_follow_page_mask will use the
existing routine huge_pte_offset to walk page tables looking for hugetlb
entries. huge_pte_offset can be overwritten by architectures, and already
handles special cases such as hugepd entries.
SeongJae Park [Mon, 7 Nov 2022 16:50:00 +0000 (16:50 +0000)]
mm/damon/dbgfs: check if rm_contexts input is for a real context
A user could write a name of a file under 'damon/' debugfs directory,
which is not a user-created context, to 'rm_contexts' file. In the case,
'dbgfs_rm_context()' just assumes it's the valid DAMON context directory
only if a file of the name exist. As a result, invalid memory access
could happen as below. Fix the bug by checking if the given input is for
a directory. This check can filter out non-context inputs because
directories under 'damon/' debugfs directory can be created via only
'mk_contexts' file.
Liam Howlett [Mon, 7 Nov 2022 16:39:02 +0000 (16:39 +0000)]
maple_tree: don't set a new maximum on the node when not reusing nodes
In RCU mode, the node limits were being updated to the last pivot which
may not be correct and would cause the metadata to be set when it
shouldn't. Fix this by not setting a new limit in this case.
Liam Howlett [Mon, 7 Nov 2022 16:38:35 +0000 (16:38 +0000)]
maple_tree: fix depth tracking in maple_state
It is possible to confuse the depth tracking in the maple state by
searching the same node for values. Fix the depth tracking by moving
where the depth is incremented closer to where the node changes level.
Also change the initial depth setting when using the root node.
Recently pud_huge() got aware of non-present entry by commit 3a194f3f8ad0
("mm/hugetlb: make pud_huge() and follow_huge_pud() aware of non-present
pud entry") to handle some special states of gigantic page. However, it's
overlooked that pud_none() always returns false when running with 2-level
paging, and as a result pud_huge() can return true pointlessly.
Introduce "#if CONFIG_PGTABLE_LEVELS > 2" to pud_huge() to deal with this.
Johannes Weiner [Thu, 3 Nov 2022 21:34:31 +0000 (17:34 -0400)]
fs: fix leaked psi pressure state
When psi annotations were added to to btrfs compression reads, the psi
state tracking over add_ra_bio_pages and btrfs_submit_compressed_read was
faulty. A pressure state, once entered, is never left. This results in
incorrectly elevated pressure, which triggers OOM kills.
pflags record the *previous* memstall state when we enter a new one. The
code tried to initialize pflags to 1, and then optimize the leave call
when we either didn't enter a memstall, or were already inside a nested
stall. However, there can be multiple PageWorkingset pages in the bio, at
which point it's that path itself that enters repeatedly and overwrites
pflags. This causes us to miss the exit.
Enter the stall only once if needed, then unwind correctly.
erofs has the same problem, fix that up too. And move the memstall exit
past submit_bio() to restore submit accounting originally added by b8e24a9300b0 ("block: annotate refault stalls from IO submission").
Ryusuke Konishi [Fri, 4 Nov 2022 14:29:59 +0000 (23:29 +0900)]
nilfs2: fix use-after-free bug of ns_writer on remount
If a nilfs2 filesystem is downgraded to read-only due to metadata
corruption on disk and is remounted read/write, or if emergency read-only
remount is performed, detaching a log writer and synchronizing the
filesystem can be done at the same time.
In these cases, use-after-free of the log writer (hereinafter
nilfs->ns_writer) can happen as shown in the scenario below:
While Task1 is sleeping, nilfs->ns_writer is freed by Task2. After Task1
waked up, Task1 accesses nilfs->ns_writer which is already freed. This
scenario diagram is based on the Shigeru Yoshida's post [1].
This patch fixes the issue by not detaching nilfs->ns_writer on remount so
that this UAF race doesn't happen. Along with this change, this patch
also inserts a few necessary read-only checks with superblock instance
where only the ns_writer pointer was used to check if the filesystem is
read-only.
x86/traps: avoid KMSAN bugs originating from handle_bug()
There is a case in exc_invalid_op handler that is executed outside the
irqentry_enter()/irqentry_exit() region when an UD2 instruction is used to
encode a call to __warn().
In that case the `struct pt_regs` passed to the interrupt handler is never
unpoisoned by KMSAN (this is normally done in irqentry_enter()), which
leads to false positives inside handle_bug().
Use kmsan_unpoison_entry_regs() to explicitly unpoison those registers
before using them.
As pointed out by Peter Zijlstra, __msan_poison_alloca() does not play
well with IRQ code when PREEMPT_RT is on, because in that mode even
GFP_ATOMIC allocations cannot be performed.
Fixing this would require making stackdepot completely lockless, which is
quite challenging and may be excessive for the time being.
Instead, make sure KMSAN is incompatible with PREEMPT_RT, like other debug
configs are.
Kconfig.debug: ensure early check for KMSAN in CONFIG_KMSAN_WARN
As pointed out by Masahiro Yamada, Kconfig picks up the first default
entry which has true 'if' condition. Hence, the previously added check
for KMSAN was never used, because it followed the checks for 64BIT and
!64BIT.
Put KMSAN check before others to ensure it is always applied.
Make sure usercopy hooks from linux/instrumented.h are invoked for
copy_from_user_nmi(). This fixes KMSAN false positives reported when
dumping opcodes for a stack trace.
Vasily Gorbik [Wed, 2 Nov 2022 18:09:17 +0000 (19:09 +0100)]
mm: hugetlb_vmemmap: include missing linux/moduleparam.h
The kernel test robot reported build failures with a 'randconfig' on s390:
>> mm/hugetlb_vmemmap.c:421:11: error: a function declaration without a
prototype is deprecated in all versions of C [-Werror,-Wstrict-prototypes]
core_param(hugetlb_free_vmemmap, vmemmap_optimize_enabled, bool, 0);
^
Peter Xu [Wed, 2 Nov 2022 18:41:52 +0000 (14:41 -0400)]
mm/shmem: use page_mapping() to detect page cache for uffd continue
mfill_atomic_install_pte() checks page->mapping to detect whether one page
is used in the page cache. However as pointed out by Matthew, the page
can logically be a tail page rather than always the head in the case of
uffd minor mode with UFFDIO_CONTINUE. It means we could wrongly install
one pte with shmem thp tail page assuming it's an anonymous page.
It's not that clear even for anonymous page, since normally anonymous
pages also have page->mapping being setup with the anon vma. It's safe
here only because the only such caller to mfill_atomic_install_pte() is
always passing in a newly allocated page (mcopy_atomic_pte()), whose
page->mapping is not yet setup. However that's not extremely obvious
either.
Pankaj Gupta [Wed, 2 Nov 2022 16:07:28 +0000 (11:07 -0500)]
mm/memremap.c: map FS_DAX device memory as decrypted
virtio_pmem use devm_memremap_pages() to map the device memory. By
default this memory is mapped as encrypted with SEV. Guest reboot changes
the current encryption key and guest no longer properly decrypts the FSDAX
device meta data.
Mark the corresponding device memory region for FSDAX devices (mapped with
memremap_pages) as decrypted to retain the persistent memory property.
The sparc64 impl of pte_mkdirty() is definitely slightly special in that
it leverages a code patching mechanism for sun4u/sun4v on relevant pgtable
entry operations.
Before having a clue of why the sparc64 is special and caused the patch to
SIGSEGV the processes, revert the patch for now. The swap path of dirty
bit inheritage is kept because that's using the swap shared code so we
assume it'll not be affected.
Ryusuke Konishi [Sat, 29 Oct 2022 04:49:12 +0000 (13:49 +0900)]
nilfs2: fix deadlock in nilfs_count_free_blocks()
A semaphore deadlock can occur if nilfs_get_block() detects metadata
corruption while locating data blocks and a superblock writeback occurs at
the same time:
task 1 task 2
------ ------
* A file operation *
nilfs_truncate()
nilfs_get_block()
down_read(rwsem A) <--
nilfs_bmap_lookup_contig()
... generic_shutdown_super()
nilfs_put_super()
* Prepare to write superblock *
down_write(rwsem B) <--
nilfs_cleanup_super()
* Detect b-tree corruption * nilfs_set_log_cursor()
nilfs_bmap_convert_error() nilfs_count_free_blocks()
__nilfs_error() down_read(rwsem A) <--
nilfs_set_error()
down_write(rwsem B) <--
*** DEADLOCK ***
Here, nilfs_get_block() readlocks rwsem A (= NILFS_MDT(dat_inode)->mi_sem)
and then calls nilfs_bmap_lookup_contig(), but if it fails due to metadata
corruption, __nilfs_error() is called from nilfs_bmap_convert_error()
inside the lock section.
Since __nilfs_error() calls nilfs_set_error() unless the filesystem is
read-only and nilfs_set_error() attempts to writelock rwsem B (=
nilfs->ns_sem) to write back superblock exclusively, hierarchical lock
acquisition occurs in the order rwsem A -> rwsem B.
Now, if another task starts updating the superblock, it may writelock
rwsem B during the lock sequence above, and can deadlock trying to
readlock rwsem A in nilfs_count_free_blocks().
However, there is actually no need to take rwsem A in
nilfs_count_free_blocks() because it, within the lock section, only reads
a single integer data on a shared struct with
nilfs_sufile_get_ncleansegs(). This has been the case after commit aa474a220180 ("nilfs2: add local variable to cache the number of clean
segments"), that is, even before this bug was introduced.
So, this resolves the deadlock problem by just not taking the semaphore in
nilfs_count_free_blocks().
The root cause was traced to an error handing path in mmap_region() when
arch_validate_flags() or mas_preallocate() fails. In the shared anonymous
mapping sence, vma will be setuped and mapped with a new shared anonymous
file via shmem_zero_setup(). So in this case, the file resource needs to
be released.
Fix it by calling fput(vma->vm_file) and unmap_region() when
arch_validate_flags() or mas_preallocate() returns an error in the shared
anonymous mapping sence.
James Houghton [Tue, 18 Oct 2022 20:01:25 +0000 (20:01 +0000)]
hugetlbfs: don't delete error page from pagecache
This change is very similar to the change that was made for shmem [1], and
it solves the same problem but for HugeTLBFS instead.
Currently, when poison is found in a HugeTLB page, the page is removed
from the page cache. That means that attempting to map or read that
hugepage in the future will result in a new hugepage being allocated
instead of notifying the user that the page was poisoned. As [1] states,
this is effectively memory corruption.
The fix is to leave the page in the page cache. If the user attempts to
use a poisoned HugeTLB page with a syscall, the syscall will fail with
EIO, the same error code that shmem uses. For attempts to map the page,
the thread will get a BUS_MCEERR_AR SIGBUS.
Liam Howlett [Fri, 28 Oct 2022 18:04:30 +0000 (18:04 +0000)]
maple_tree: reorganize testing to restore module testing
Along the development cycle, the testing code support for module/in-kernel
compiles was removed. Restore this functionality by moving any internal
API tests to the userspace side, as well as threading tests. Fix the
lockdep issues and add a way to reduce memory usage so the tests can
complete with KASAN + memleak detection. Make the tests work on 32 bit
hosts where possible and detect 32 bit hosts in the radix test suite.
Linus Torvalds [Sun, 6 Nov 2022 21:09:52 +0000 (13:09 -0800)]
Merge tag 'cxl-fixes-for-6.1-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/cxl/cxl
Pull cxl fixes from Dan Williams:
"Several fixes for CXL region creation crashes, leaks and failures.
This is mainly fallout from the original implementation of dynamic CXL
region creation (instantiate new physical memory pools) that arrived
in v6.0-rc1.
Given the theme of "failures in the presence of pass-through decoders"
this also includes new regression test infrastructure for that case.
Summary:
- Fix region creation crash with pass-through decoders
- Fix region creation crash when no decoder allocation fails
- Fix region creation crash when scanning regions to enforce the
increasing physical address order constraint that CXL mandates
- Fix a memory leak for cxl_pmem_region objects, track 1:N instead of
1:1 memory-device-to-region associations.
- Fix a memory leak for cxl_region objects when regions with active
targets are deleted
- Fix assignment of NUMA nodes to CXL regions by CFMWS (CXL Window)
emulated proximity domains.
- Fix region creation failure for switch attached devices downstream
of a single-port host-bridge
- Fix false positive memory leak of cxl_region objects by recycling
recently used region ids rather than freeing them
- Add regression test infrastructure for a pass-through decoder
configuration
- Fix some mailbox payload handling corner cases"
* tag 'cxl-fixes-for-6.1-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/cxl/cxl:
cxl/region: Recycle region ids
cxl/region: Fix 'distance' calculation with passthrough ports
tools/testing/cxl: Add a single-port host-bridge regression config
tools/testing/cxl: Fix some error exits
cxl/pmem: Fix cxl_pmem_region and cxl_memdev leak
cxl/region: Fix cxl_region leak, cleanup targets at region delete
cxl/region: Fix region HPA ordering validation
cxl/pmem: Use size_add() against integer overflow
cxl/region: Fix decoder allocation crash
ACPI: NUMA: Add CXL CFMWS 'nodes' to the possible nodes set
cxl/pmem: Fix failure to account for 8 byte header for writes to the device LSA.
cxl/region: Fix null pointer dereference due to pass through decoder commit
cxl/mbox: Add a check on input payload size
Linus Torvalds [Sun, 6 Nov 2022 20:59:12 +0000 (12:59 -0800)]
Merge tag 'hwmon-for-v6.1-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/groeck/linux-staging
Pull hwmon fixes from Guenter Roeck:
"Fix two regressions:
- Commit 54cc3dbfc10d ("hwmon: (pmbus) Add regulator supply into
macro") resulted in regulator undercount when disabling regulators.
Revert it.
- The thermal subsystem rework caused the scmi driver to no longer
register with the thermal subsystem because index values no longer
match. To fix the problem, the scmi driver now directly registers
with the thermal subsystem, no longer through the hwmon core"
* tag 'hwmon-for-v6.1-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/groeck/linux-staging:
Revert "hwmon: (pmbus) Add regulator supply into macro"
hwmon: (scmi) Register explicitly with Thermal Framework
Linus Torvalds [Sun, 6 Nov 2022 20:41:32 +0000 (12:41 -0800)]
Merge tag 'perf_urgent_for_v6.1_rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull perf fixes from Borislav Petkov:
- Add Cooper Lake's stepping to the PEBS guest/host events isolation
fixed microcode revisions checking quirk
- Update Icelake and Sapphire Rapids events constraints
- Use the standard energy unit for Sapphire Rapids in RAPL
- Fix the hw_breakpoint test to fail more graciously on !SMP configs
* tag 'perf_urgent_for_v6.1_rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
perf/x86/intel: Add Cooper Lake stepping to isolation_ucodes[]
perf/x86/intel: Fix pebs event constraints for SPR
perf/x86/intel: Fix pebs event constraints for ICL
perf/x86/rapl: Use standard Energy Unit for SPR Dram RAPL domain
perf/hw_breakpoint: test: Skip the test if dependencies unmet
Linus Torvalds [Sun, 6 Nov 2022 20:36:47 +0000 (12:36 -0800)]
Merge tag 'x86_urgent_for_v6.1_rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 fixes from Borislav Petkov:
- Add new Intel CPU models
- Enforce that TDX guests are successfully loaded only on TDX hardware
where virtualization exception (#VE) delivery on kernel memory is
disabled because handling those in all possible cases is "essentially
impossible"
- Add the proper include to the syscall wrappers so that BTF can see
the real pt_regs definition and not only the forward declaration
* tag 'x86_urgent_for_v6.1_rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/cpu: Add several Intel server CPU model numbers
x86/tdx: Panic on bad configs that #VE on "private" memory access
x86/tdx: Prepare for using "INFO" call for a second purpose
x86/syscall: Include asm/ptrace.h in syscall_wrapper header
Linus Torvalds [Sun, 6 Nov 2022 20:23:10 +0000 (12:23 -0800)]
Merge tag 'kbuild-fixes-v6.1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild
Pull Kbuild fixes from Masahiro Yamada:
- Use POSIX-compatible grep options
- Document git-related tips for reproducible builds
- Fix a typo in the modpost rule
- Suppress SIGPIPE error message from gcc-ar and llvm-ar
- Fix segmentation fault in the menuconfig search
* tag 'kbuild-fixes-v6.1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild:
kconfig: fix segmentation fault in menuconfig search
kbuild: fix SIGPIPE error message for AR=gcc-ar and AR=llvm-ar
kbuild: fix typo in modpost
Documentation: kbuild: Add description of git for reproducible builds
kbuild: use POSIX-compatible grep option
Linus Torvalds [Sun, 6 Nov 2022 18:46:59 +0000 (10:46 -0800)]
Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm
Pull kvm fixes from Paolo Bonzini:
"ARM:
- Fix the pKVM stage-1 walker erronously using the stage-2 accessor
- Correctly convert vcpu->kvm to a hyp pointer when generating an
exception in a nVHE+MTE configuration
- Check that KVM_CAP_DIRTY_LOG_* are valid before enabling them
- Fix SMPRI_EL1/TPIDR2_EL0 trapping on VHE
- Document the boot requirements for FGT when entering the kernel at
EL1
x86:
- Use SRCU to protect zap in __kvm_set_or_clear_apicv_inhibit()
- Make argument order consistent for kvcalloc()
- Userspace API fixes for DEBUGCTL and LBRs"
* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
KVM: x86: Fix a typo about the usage of kvcalloc()
KVM: x86: Use SRCU to protect zap in __kvm_set_or_clear_apicv_inhibit()
KVM: VMX: Ignore guest CPUID for host userspace writes to DEBUGCTL
KVM: VMX: Fold vmx_supported_debugctl() into vcpu_supported_debugctl()
KVM: VMX: Advertise PMU LBRs if and only if perf supports LBRs
arm64: booting: Document our requirements for fine grained traps with SME
KVM: arm64: Fix SMPRI_EL1/TPIDR2_EL0 trapping on VHE
KVM: Check KVM_CAP_DIRTY_LOG_{RING, RING_ACQ_REL} prior to enabling them
KVM: arm64: Fix bad dereference on MTE-enabled systems
KVM: arm64: Use correct accessor to parse stage-1 PTEs
Linus Torvalds [Sun, 6 Nov 2022 18:42:29 +0000 (10:42 -0800)]
Merge tag 'for-linus-6.1-rc4-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip
Pull xen fixes from Juergen Gross:
"One fix for silencing a smatch warning, and a small cleanup patch"
* tag 'for-linus-6.1-rc4-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip:
x86/xen: simplify sysenter and syscall setup
x86/xen: silence smatch warning in pmu_msr_chk_emulated()
Linus Torvalds [Sun, 6 Nov 2022 18:30:29 +0000 (10:30 -0800)]
Merge tag 'ext4_for_linus_stable' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4
Pull ext4 fixes from Ted Ts'o:
"Fix a number of bugs, including some regressions, the most serious of
which was one which would cause online resizes to fail with file
systems with metadata checksums enabled.
Also fix a warning caused by the newly added fortify string checker,
plus some bugs that were found using fuzzed file systems"
* tag 'ext4_for_linus_stable' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4:
ext4: fix fortify warning in fs/ext4/fast_commit.c:1551
ext4: fix wrong return err in ext4_load_and_init_journal()
ext4: fix warning in 'ext4_da_release_space'
ext4: fix BUG_ON() when directory entry has invalid rec_len
ext4: update the backup superblock's at the end of the online resize
Linus Torvalds [Sun, 6 Nov 2022 18:19:39 +0000 (10:19 -0800)]
Merge tag '6.1-rc4-smb3-fixes' of git://git.samba.org/sfrench/cifs-2.6
Pull cifs fixes from Steve French:
"One symlink handling fix and two fixes foir multichannel issues with
iterating channels, including for oplock breaks when leases are
disabled"
* tag '6.1-rc4-smb3-fixes' of git://git.samba.org/sfrench/cifs-2.6:
cifs: fix use-after-free on the link name
cifs: avoid unnecessary iteration of tcp sessions
cifs: always iterate smb sessions using primary channel
Linus Torvalds [Sun, 6 Nov 2022 17:57:38 +0000 (09:57 -0800)]
Merge tag 'trace-v6.1-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace
Pull `lTracing fixes for 6.1-rc3:
- Fixed NULL pointer dereference in the ring buffer wait-waiters code
for machines that have less CPUs than what nr_cpu_ids returns.
The buffer array is of size nr_cpu_ids, but only the online CPUs get
initialized.
- Fixed use after free call in ftrace_shutdown.
- Fix accounting of if a kprobe is enabled
- Fix NULL pointer dereference on error path of fprobe rethook_alloc().
- Fix unregistering of fprobe_kprobe_handler
- Fix memory leak in kprobe test module
* tag 'trace-v6.1-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
tracing: kprobe: Fix memory leak in test_gen_kprobe/kretprobe_cmd()
tracing/fprobe: Fix to check whether fprobe is registered correctly
fprobe: Check rethook_alloc() return in rethook initialization
kprobe: reverse kp->flags when arm_kprobe failed
ftrace: Fix use-after-free for dynamic ftrace_ops
ring-buffer: Check for NULL cpu_buffer in ring_buffer_wake_waiters()
Jason Yan [Tue, 25 Oct 2022 04:02:06 +0000 (12:02 +0800)]
ext4: fix wrong return err in ext4_load_and_init_journal()
The return value is wrong in ext4_load_and_init_journal(). The local
variable 'err' need to be initialized before goto out. The original code
in __ext4_fill_super() is fine because it has two return values 'ret'
and 'err' and 'ret' is initialized as -EINVAL. After we factor out
ext4_load_and_init_journal(), this code is broken. So fix it by directly
returning -EINVAL in the error handler path.
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