[ Upstream commit 7116c0af4b ]
Readahead was factored to call generic_fadvise. That refactor added an
S_ISREG restriction which broke readahead on block devices.
In addition to S_ISREG, this change checks S_ISBLK to fix block device
readahead. There is no change in behavior with any file type besides block
devices in this change.
Fixes: 3d8f761531 ("vfs: implement readahead(2) using POSIX_FADV_WILLNEED")
Signed-off-by: Reuben Hawkins <reubenhwk@gmail.com>
Link: https://lore.kernel.org/r/20231003015704.2415-1-reubenhwk@gmail.com
Reviewed-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit babddbfb7d upstream.
when the checked address is illegal,the corresponding shadow address from
kasan_mem_to_shadow may have no mapping in mmu table. Access such shadow
address causes kernel oops. Here is a sample about oops on arm64(VA
39bit) with KASAN_SW_TAGS and KASAN_OUTLINE on:
[ffffffb80aaaaaaa] pgd=000000005d3ce003, p4d=000000005d3ce003,
pud=000000005d3ce003, pmd=0000000000000000
Internal error: Oops: 0000000096000006 [#1] PREEMPT SMP
Modules linked in:
CPU: 3 PID: 100 Comm: sh Not tainted 6.6.0-rc1-dirty #43
Hardware name: linux,dummy-virt (DT)
pstate: 80000005 (Nzcv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--)
pc : __hwasan_load8_noabort+0x5c/0x90
lr : do_ib_ob+0xf4/0x110
ffffffb80aaaaaaa is the shadow address for efffff80aaaaaaaa.
The problem is reading invalid shadow in kasan_check_range.
The generic kasan also has similar oops.
It only reports the shadow address which causes oops but not
the original address.
Commit 2f004eea0fc8("x86/kasan: Print original address on #GP")
introduce to kasan_non_canonical_hook but limit it to KASAN_INLINE.
This patch extends it to KASAN_OUTLINE mode.
Link: https://lkml.kernel.org/r/20231009073748.159228-1-haibo.li@mediatek.com
Fixes: 2f004eea0fc8("x86/kasan: Print original address on #GP")
Signed-off-by: Haibo Li <haibo.li@mediatek.com>
Reviewed-by: Andrey Konovalov <andreyknvl@gmail.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Haibo Li <haibo.li@mediatek.com>
Cc: Matthias Brugger <matthias.bgg@gmail.com>
Cc: Vincenzo Frascino <vincenzo.frascino@arm.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Kees Cook <keescook@chromium.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 229e225376 upstream.
do_pages_move does not handle compat pointers for the page list.
correctly. Add in_compat_syscall check and appropriate get_user fetch
when iterating the page list.
It makes the syscall in compat mode (32-bit userspace, 64-bit kernel)
work the same way as the native 32-bit syscall again, restoring the
behavior before my broken commit 5b1b561ba7 ("mm: simplify
compat_sys_move_pages").
More specifically, my patch moved the parsing of the 'pages' array from
the main entry point into do_pages_stat(), which left the syscall
working correctly for the 'stat' operation (nodes = NULL), while the
'move' operation (nodes != NULL) is now missing the conversion and
interprets 'pages' as an array of 64-bit pointers instead of the
intended 32-bit userspace pointers.
It is possible that nobody noticed this bug because the few
applications that actually call move_pages are unlikely to run in
compat mode because of their large memory requirements, but this
clearly fixes a user-visible regression and should have been caught by
ltp.
Link: https://lkml.kernel.org/r/20231003144857.752952-1-gregory.price@memverge.com
Fixes: 5b1b561ba7 ("mm: simplify compat_sys_move_pages")
Signed-off-by: Gregory Price <gregory.price@memverge.com>
Reported-by: Arnd Bergmann <arnd@arndb.de>
Co-developed-by: Arnd Bergmann <arnd@arndb.de>
Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 61e21cf2d2 upstream.
When guard page debug is enabled and set_page_guard returns success, we
miss to forward page to point to start of next split range and we will do
split unexpectedly in page range without target page. Move start page
update before set_page_guard to fix this.
As we split to wrong target page, then splited pages are not able to merge
back to original order when target page is put back and splited pages
except target page is not usable. To be specific:
Consider target page is the third page in buddy page with order 2.
| buddy-2 | Page | Target | Page |
After break down to target page, we will only set first page to Guard
because of bug.
| Guard | Page | Target | Page |
When we try put_page_back_buddy with target page, the buddy page of target
if neither guard nor buddy, Then it's not able to construct original page
with order 2
| Guard | Page | buddy-0 | Page |
All pages except target page is not in free list and is not usable.
Link: https://lkml.kernel.org/r/20230927094401.68205-1-shikemeng@huaweicloud.com
Fixes: 06be6ff3d2 ("mm,hwpoison: rework soft offline for free pages")
Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com>
Acked-by: Naoya Horiguchi <naoya.horiguchi@nec.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 0818e739b5 upstream.
It is unsafe to dump vmalloc area information when trying to do so from
some contexts. Add a safer trylock version of the same function to do a
best-effort VMA finding and use it from vmalloc_dump_obj().
[applied test robot feedback on unused function fix.]
[applied Uladzislau feedback on locking.]
Link: https://lkml.kernel.org/r/20230904180806.1002832-1-joel@joelfernandes.org
Fixes: 98f180837a ("mm: Make mem_dump_obj() handle vmalloc() memory")
Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Reviewed-by: Uladzislau Rezki (Sony) <urezki@gmail.com>
Reported-by: Zhen Lei <thunder.leizhen@huaweicloud.com>
Cc: Paul E. McKenney <paulmck@kernel.org>
Cc: Zqiang <qiang.zhang1211@gmail.com>
Cc: <stable@vger.kernel.org>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit c83ad36a18 upstream.
Currently, for double invoke call_rcu(), will dump rcu_head objects memory
info, if the objects is not allocated from the slab allocator, the
vmalloc_dump_obj() will be invoke and the vmap_area_lock spinlock need to
be held, since the call_rcu() can be invoked in interrupt context,
therefore, there is a possibility of spinlock deadlock scenarios.
And in Preempt-RT kernel, the rcutorture test also trigger the following
lockdep warning:
BUG: sleeping function called from invalid context at kernel/locking/spinlock_rt.c:48
in_atomic(): 1, irqs_disabled(): 1, non_block: 0, pid: 1, name: swapper/0
preempt_count: 1, expected: 0
RCU nest depth: 1, expected: 1
3 locks held by swapper/0/1:
#0: ffffffffb534ee80 (fullstop_mutex){+.+.}-{4:4}, at: torture_init_begin+0x24/0xa0
#1: ffffffffb5307940 (rcu_read_lock){....}-{1:3}, at: rcu_torture_init+0x1ec7/0x2370
#2: ffffffffb536af40 (vmap_area_lock){+.+.}-{3:3}, at: find_vmap_area+0x1f/0x70
irq event stamp: 565512
hardirqs last enabled at (565511): [<ffffffffb379b138>] __call_rcu_common+0x218/0x940
hardirqs last disabled at (565512): [<ffffffffb5804262>] rcu_torture_init+0x20b2/0x2370
softirqs last enabled at (399112): [<ffffffffb36b2586>] __local_bh_enable_ip+0x126/0x170
softirqs last disabled at (399106): [<ffffffffb43fef59>] inet_register_protosw+0x9/0x1d0
Preemption disabled at:
[<ffffffffb58040c3>] rcu_torture_init+0x1f13/0x2370
CPU: 0 PID: 1 Comm: swapper/0 Tainted: G W 6.5.0-rc4-rt2-yocto-preempt-rt+ #15
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.16.2-0-gea1b7a073390-prebuilt.qemu.org 04/01/2014
Call Trace:
<TASK>
dump_stack_lvl+0x68/0xb0
dump_stack+0x14/0x20
__might_resched+0x1aa/0x280
? __pfx_rcu_torture_err_cb+0x10/0x10
rt_spin_lock+0x53/0x130
? find_vmap_area+0x1f/0x70
find_vmap_area+0x1f/0x70
vmalloc_dump_obj+0x20/0x60
mem_dump_obj+0x22/0x90
__call_rcu_common+0x5bf/0x940
? debug_smp_processor_id+0x1b/0x30
call_rcu_hurry+0x14/0x20
rcu_torture_init+0x1f82/0x2370
? __pfx_rcu_torture_leak_cb+0x10/0x10
? __pfx_rcu_torture_leak_cb+0x10/0x10
? __pfx_rcu_torture_init+0x10/0x10
do_one_initcall+0x6c/0x300
? debug_smp_processor_id+0x1b/0x30
kernel_init_freeable+0x2b9/0x540
? __pfx_kernel_init+0x10/0x10
kernel_init+0x1f/0x150
ret_from_fork+0x40/0x50
? __pfx_kernel_init+0x10/0x10
ret_from_fork_asm+0x1b/0x30
</TASK>
The previous patch fixes this by using the deadlock-safe best-effort
version of find_vm_area. However, in case of failure print the fact that
the pointer was a vmalloc pointer so that we print at least something.
Link: https://lkml.kernel.org/r/20230904180806.1002832-2-joel@joelfernandes.org
Fixes: 98f180837a ("mm: Make mem_dump_obj() handle vmalloc() memory")
Signed-off-by: Zqiang <qiang.zhang1211@gmail.com>
Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Reported-by: Zhen Lei <thunder.leizhen@huaweicloud.com>
Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Paul E. McKenney <paulmck@kernel.org>
Cc: Uladzislau Rezki (Sony) <urezki@gmail.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit ac8a529621 ]
Now there are two indicators of socket memory pressure sit inside
struct mem_cgroup, socket_pressure and tcpmem_pressure, indicating
memory reclaim pressure in memcg->memory and ->tcpmem respectively.
When in legacy mode (cgroupv1), the socket memory is charged into
->tcpmem which is independent of ->memory, so socket_pressure has
nothing to do with socket's pressure at all. Things could be worse
by taking socket_pressure into consideration in legacy mode, as a
pressure in ->memory can lead to premature reclamation/throttling
in socket.
While for the default mode (cgroupv2), the socket memory is charged
into ->memory, and ->tcpmem/->tcpmem_pressure are simply not used.
So {socket,tcpmem}_pressure are only used in default/legacy mode
respectively for indicating socket memory pressure. This patch fixes
the pieces of code that make mixed use of both.
Fixes: 8e8ae64524 ("mm: memcontrol: hook up vmpressure to socket pressure")
Signed-off-by: Abel Wu <wuyun.abel@bytedance.com>
Acked-by: Shakeel Butt <shakeelb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 0200679fc7 ]
A while ago we received the following report:
"The other outstanding issue I noticed comes from the fact that
fsconfig syscalls may occur in a different userns than that which
called fsopen. That means that resolving the uid/gid via
current_user_ns() can save a kuid that isn't mapped in the associated
namespace when the filesystem is finally mounted. This means that it
is possible for an unprivileged user to create files owned by any
group in a tmpfs mount (since we can set the SUID bit on the tmpfs
directory), or a tmpfs that is owned by any user, including the root
group/user."
The contract for {g,u}id mount options and {g,u}id values in general set
from userspace has always been that they are translated according to the
caller's idmapping. In so far, tmpfs has been doing the correct thing.
But since tmpfs is mountable in unprivileged contexts it is also
necessary to verify that the resulting {k,g}uid is representable in the
namespace of the superblock to avoid such bugs as above.
The new mount api's cross-namespace delegation abilities are already
widely used. After having talked to a bunch of userspace this is the
most faithful solution with minimal regression risks. I know of one
users - systemd - that makes use of the new mount api in this way and
they don't set unresolable {g,u}ids. So the regression risk is minimal.
Link: https://lore.kernel.org/lkml/CALxfFW4BXhEwxR0Q5LSkg-8Vb4r2MONKCcUCVioehXQKr35eHg@mail.gmail.com
Fixes: f32356261d ("vfs: Convert ramfs, shmem, tmpfs, devtmpfs, rootfs to use the new mount API")
Reviewed-by: "Seth Forshee (DigitalOcean)" <sforshee@kernel.org>
Reported-by: Seth Jenkins <sethjenkins@google.com>
Message-Id: <20230801-vfs-fs_context-uidgid-v1-1-daf46a050bbf@kernel.org>
Signed-off-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit e2c1ab070f ]
When page_handle_poison() fails to handle the hugepage or free page in
retry path, soft_offline_page() will return 0 while -EBUSY is expected in
this case.
Consequently the user will think soft_offline_page succeeds while it in
fact failed. So the user will not try again later in this case.
Link: https://lkml.kernel.org/r/20230627112808.1275241-1-linmiaohe@huawei.com
Fixes: b94e02822d ("mm,hwpoison: try to narrow window race for free pages")
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Acked-by: Naoya Horiguchi <naoya.horiguchi@nec.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit a50420c797 upstream.
flush_cache_vmap() must be called after new vmalloc mappings are installed
in the page table in order to allow architectures to make sure the new
mapping is visible.
It could lead to a panic since on some architectures (like powerpc),
the page table walker could see the wrong pte value and trigger a
spurious page fault that can not be resolved (see commit f1cb8f9beb
("powerpc/64s/radix: avoid ptesync after set_pte and
ptep_set_access_flags")).
But actually the patch is aiming at riscv: the riscv specification
allows the caching of invalid entries in the TLB, and since we recently
removed the vmalloc page fault handling, we now need to emit a tlb
shootdown whenever a new vmalloc mapping is emitted
(https://lore.kernel.org/linux-riscv/20230725132246.817726-1-alexghiti@rivosinc.com/).
That's a temporary solution, there are ways to avoid that :)
Link: https://lkml.kernel.org/r/20230809164633.1556126-1-alexghiti@rivosinc.com
Fixes: 3e9a9e256b ("mm: add a vmap_pfn function")
Reported-by: Dylan Jhong <dylan@andestech.com>
Closes: https://lore.kernel.org/linux-riscv/ZMytNY2J8iyjbPPy@atctrx.andestech.com/
Signed-off-by: Alexandre Ghiti <alexghiti@rivosinc.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Palmer Dabbelt <palmer@rivosinc.com>
Acked-by: Palmer Dabbelt <palmer@rivosinc.com>
Reviewed-by: Dylan Jhong <dylan@andestech.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit c11d34fa13 upstream.
It is racy to non-atomically read a pte, then clear the young bit, then
write it back as this could discard dirty information. Further, it is bad
practice to directly set a pte entry within a table. Instead clearing
young must go through the arch-provided helper,
ptep_test_and_clear_young() to ensure it is modified atomically and to
give the arch code visibility and allow it to check (and potentially
modify) the operation.
Link: https://lkml.kernel.org/r/20230602092949.545577-3-ryan.roberts@arm.com
Fixes: 3f49584b26 ("mm/damon: implement primitives for the virtual memory address spaces").
Signed-off-by: Ryan Roberts <ryan.roberts@arm.com>
Reviewed-by: Zi Yan <ziy@nvidia.com>
Reviewed-by: SeongJae Park <sj@kernel.org>
Reviewed-by: Mike Rapoport (IBM) <rppt@kernel.org>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Lorenzo Stoakes <lstoakes@gmail.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Uladzislau Rezki (Sony) <urezki@gmail.com>
Cc: Yu Zhao <yuzhao@google.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: SeongJae Park <sj@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 36ce9d76b0 upstream.
As the ramfs-based tmpfs uses ramfs_init_fs_context() for the
init_fs_context method, which allocates fc->s_fs_info, use ramfs_kill_sb()
to free it and avoid a memory leak.
Link: https://lkml.kernel.org/r/20230607161523.2876433-1-roberto.sassu@huaweicloud.com
Fixes: c3b1b1cbf0 ("ramfs: add support for "mode=" mount option")
Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
From: Tony Luck <tony.luck@intel.com>
commit d302c2398b upstream.
Cannot call memory_failure() directly from the fault handler because
mmap_lock (and others) are held.
It is important, but not urgent, to mark the source page as h/w poisoned
and unmap it from other tasks.
Use memory_failure_queue() to request a call to memory_failure() for the
page with the error.
Also provide a stub version for CONFIG_MEMORY_FAILURE=n
Cc: <stable@vger.kernel.org>
Link: https://lkml.kernel.org/r/20221021200120.175753-3-tony.luck@intel.com
Signed-off-by: Tony Luck <tony.luck@intel.com>
Reviewed-by: Miaohe Lin <linmiaohe@huawei.com>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Naoya Horiguchi <naoya.horiguchi@nec.com>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Shuai Xue <xueshuai@linux.alibaba.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
[ Due to missing commits
e591ef7d96 ("mm,hwpoison,hugetlb,memory_hotplug: hotremove memory section with hwpoisoned hugepage")
5033091de8 ("mm/hwpoison: introduce per-memory_block hwpoison counter")
The impact of e591ef7d96 is its introduction of an additional flag in
__get_huge_page_for_hwpoison() that serves as an indication a hwpoisoned
hugetlb page should have its migratable bit cleared.
The impact of 5033091de8 is contexual.
Resolve by ignoring both missing commits. - jane]
Signed-off-by: Jane Chu <jane.chu@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit a873dfe103 upstream.
Patch series "Copy-on-write poison recovery", v3.
Part 1 deals with the process that triggered the copy on write fault with
a store to a shared read-only page. That process is send a SIGBUS with
the usual machine check decoration to specify the virtual address of the
lost page, together with the scope.
Part 2 sets up to asynchronously take the page with the uncorrected error
offline to prevent additional machine check faults. H/t to Miaohe Lin
<linmiaohe@huawei.com> and Shuai Xue <xueshuai@linux.alibaba.com> for
pointing me to the existing function to queue a call to memory_failure().
On x86 there is some duplicate reporting (because the error is also
signalled by the memory controller as well as by the core that triggered
the machine check). Console logs look like this:
This patch (of 2):
If the kernel is copying a page as the result of a copy-on-write
fault and runs into an uncorrectable error, Linux will crash because
it does not have recovery code for this case where poison is consumed
by the kernel.
It is easy to set up a test case. Just inject an error into a private
page, fork(2), and have the child process write to the page.
I wrapped that neatly into a test at:
git://git.kernel.org/pub/scm/linux/kernel/git/aegl/ras-tools.git
just enable ACPI error injection and run:
# ./einj_mem-uc -f copy-on-write
Add a new copy_user_highpage_mc() function that uses copy_mc_to_kernel()
on architectures where that is available (currently x86 and powerpc).
When an error is detected during the page copy, return VM_FAULT_HWPOISON
to caller of wp_page_copy(). This propagates up the call stack. Both x86
and powerpc have code in their fault handler to deal with this code by
sending a SIGBUS to the application.
Note that this patch avoids a system crash and signals the process that
triggered the copy-on-write action. It does not take any action for the
memory error that is still in the shared page. To handle that a call to
memory_failure() is needed. But this cannot be done from wp_page_copy()
because it holds mmap_lock(). Perhaps the architecture fault handlers
can deal with this loose end in a subsequent patch?
On Intel/x86 this loose end will often be handled automatically because
the memory controller provides an additional notification of the h/w
poison in memory, the handler for this will call memory_failure(). This
isn't a 100% solution. If there are multiple errors, not all may be
logged in this way.
Cc: <stable@vger.kernel.org>
[tony.luck@intel.com: add call to kmsan_unpoison_memory(), per Miaohe Lin]
Link: https://lkml.kernel.org/r/20221031201029.102123-2-tony.luck@intel.com
Link: https://lkml.kernel.org/r/20221021200120.175753-1-tony.luck@intel.com
Link: https://lkml.kernel.org/r/20221021200120.175753-2-tony.luck@intel.com
Signed-off-by: Tony Luck <tony.luck@intel.com>
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Reviewed-by: Naoya Horiguchi <naoya.horiguchi@nec.com>
Reviewed-by: Miaohe Lin <linmiaohe@huawei.com>
Reviewed-by: Alexander Potapenko <glider@google.com>
Tested-by: Shuai Xue <xueshuai@linux.alibaba.com>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
[ Due to missing commits
c89357e27f ("mm: support GUP-triggered unsharing of anonymous pages")
662ce1dc9c ("delayacct: track delays from write-protect copy")
b073d7f8ae ("mm: kmsan: maintain KMSAN metadata for page operations")
The impact of c89357e27f is a name change from cow_user_page() to
__wp_page_copy_user().
The impact of 662ce1dc9c is the introduction of a new feature of
tracking write-protect copy in delayacct.
The impact of b073d7f8ae is an introduction of KASAN feature.
None of these commits establishes meaningful dependency, hence resolve by
ignoring them. - jane]
Signed-off-by: Jane Chu <jane.chu@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 935d44acf6 ]
Ensure that file_seals is non-NULL before using it in the memfd_create()
syscall. One situation in which memfd_file_seals_ptr() could return a
NULL pointer when CONFIG_SHMEM=n, oopsing the kernel.
Link: https://lkml.kernel.org/r/20230607132427.2867435-1-roberto.sassu@huaweicloud.com
Fixes: 47b9012ecd ("shmem: add sealing support to hugetlb-backed memfd")
Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com>
Cc: Marc-Andr Lureau <marcandre.lureau@redhat.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 1ba1199ec5 ]
KASAN report null-ptr-deref:
==================================================================
BUG: KASAN: null-ptr-deref in bdi_split_work_to_wbs+0x5c5/0x7b0
Write of size 8 at addr 0000000000000000 by task sync/943
CPU: 5 PID: 943 Comm: sync Tainted: 6.3.0-rc5-next-20230406-dirty #461
Call Trace:
<TASK>
dump_stack_lvl+0x7f/0xc0
print_report+0x2ba/0x340
kasan_report+0xc4/0x120
kasan_check_range+0x1b7/0x2e0
__kasan_check_write+0x24/0x40
bdi_split_work_to_wbs+0x5c5/0x7b0
sync_inodes_sb+0x195/0x630
sync_inodes_one_sb+0x3a/0x50
iterate_supers+0x106/0x1b0
ksys_sync+0x98/0x160
[...]
==================================================================
The race that causes the above issue is as follows:
cpu1 cpu2
-------------------------|-------------------------
inode_switch_wbs
INIT_WORK(&isw->work, inode_switch_wbs_work_fn)
queue_rcu_work(isw_wq, &isw->work)
// queue_work async
inode_switch_wbs_work_fn
wb_put_many(old_wb, nr_switched)
percpu_ref_put_many
ref->data->release(ref)
cgwb_release
queue_work(cgwb_release_wq, &wb->release_work)
// queue_work async
&wb->release_work
cgwb_release_workfn
ksys_sync
iterate_supers
sync_inodes_one_sb
sync_inodes_sb
bdi_split_work_to_wbs
kmalloc(sizeof(*work), GFP_ATOMIC)
// alloc memory failed
percpu_ref_exit
ref->data = NULL
kfree(data)
wb_get(wb)
percpu_ref_get(&wb->refcnt)
percpu_ref_get_many(ref, 1)
atomic_long_add(nr, &ref->data->count)
atomic64_add(i, v)
// trigger null-ptr-deref
bdi_split_work_to_wbs() traverses &bdi->wb_list to split work into all
wbs. If the allocation of new work fails, the on-stack fallback will be
used and the reference count of the current wb is increased afterwards.
If cgroup writeback membership switches occur before getting the reference
count and the current wb is released as old_wd, then calling wb_get() or
wb_put() will trigger the null pointer dereference above.
This issue was introduced in v4.3-rc7 (see fix tag1). Both
sync_inodes_sb() and __writeback_inodes_sb_nr() calls to
bdi_split_work_to_wbs() can trigger this issue. For scenarios called via
sync_inodes_sb(), originally commit 7fc5854f8c ("writeback: synchronize
sync(2) against cgroup writeback membership switches") reduced the
possibility of the issue by adding wb_switch_rwsem, but in v5.14-rc1 (see
fix tag2) removed the "inode_io_list_del_locked(inode, old_wb)" from
inode_switch_wbs_work_fn() so that wb->state contains WB_has_dirty_io,
thus old_wb is not skipped when traversing wbs in bdi_split_work_to_wbs(),
and the issue becomes easily reproducible again.
To solve this problem, percpu_ref_exit() is called under RCU protection to
avoid race between cgwb_release_workfn() and bdi_split_work_to_wbs().
Moreover, replace wb_get() with wb_tryget() in bdi_split_work_to_wbs(),
and skip the current wb if wb_tryget() fails because the wb has already
been shutdown.
Link: https://lkml.kernel.org/r/20230410130826.1492525-1-libaokun1@huawei.com
Fixes: b817525a4a ("writeback: bdi_writeback iteration must not skip dying ones")
Signed-off-by: Baokun Li <libaokun1@huawei.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Acked-by: Tejun Heo <tj@kernel.org>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Andreas Dilger <adilger.kernel@dilger.ca>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Dennis Zhou <dennis@kernel.org>
Cc: Hou Tao <houtao1@huawei.com>
Cc: yangerkun <yangerkun@huawei.com>
Cc: Zhang Yi <yi.zhang@huawei.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit 1007843a91 upstream.
syzbot is reporting circular locking dependency which involves
zonelist_update_seq seqlock [1], for this lock is checked by memory
allocation requests which do not need to be retried.
One deadlock scenario is kmalloc(GFP_ATOMIC) from an interrupt handler.
CPU0
----
__build_all_zonelists() {
write_seqlock(&zonelist_update_seq); // makes zonelist_update_seq.seqcount odd
// e.g. timer interrupt handler runs at this moment
some_timer_func() {
kmalloc(GFP_ATOMIC) {
__alloc_pages_slowpath() {
read_seqbegin(&zonelist_update_seq) {
// spins forever because zonelist_update_seq.seqcount is odd
}
}
}
}
// e.g. timer interrupt handler finishes
write_sequnlock(&zonelist_update_seq); // makes zonelist_update_seq.seqcount even
}
This deadlock scenario can be easily eliminated by not calling
read_seqbegin(&zonelist_update_seq) from !__GFP_DIRECT_RECLAIM allocation
requests, for retry is applicable to only __GFP_DIRECT_RECLAIM allocation
requests. But Michal Hocko does not know whether we should go with this
approach.
Another deadlock scenario which syzbot is reporting is a race between
kmalloc(GFP_ATOMIC) from tty_insert_flip_string_and_push_buffer() with
port->lock held and printk() from __build_all_zonelists() with
zonelist_update_seq held.
CPU0 CPU1
---- ----
pty_write() {
tty_insert_flip_string_and_push_buffer() {
__build_all_zonelists() {
write_seqlock(&zonelist_update_seq);
build_zonelists() {
printk() {
vprintk() {
vprintk_default() {
vprintk_emit() {
console_unlock() {
console_flush_all() {
console_emit_next_record() {
con->write() = serial8250_console_write() {
spin_lock_irqsave(&port->lock, flags);
tty_insert_flip_string() {
tty_insert_flip_string_fixed_flag() {
__tty_buffer_request_room() {
tty_buffer_alloc() {
kmalloc(GFP_ATOMIC | __GFP_NOWARN) {
__alloc_pages_slowpath() {
zonelist_iter_begin() {
read_seqbegin(&zonelist_update_seq); // spins forever because zonelist_update_seq.seqcount is odd
spin_lock_irqsave(&port->lock, flags); // spins forever because port->lock is held
}
}
}
}
}
}
}
}
spin_unlock_irqrestore(&port->lock, flags);
// message is printed to console
spin_unlock_irqrestore(&port->lock, flags);
}
}
}
}
}
}
}
}
}
write_sequnlock(&zonelist_update_seq);
}
}
}
This deadlock scenario can be eliminated by
preventing interrupt context from calling kmalloc(GFP_ATOMIC)
and
preventing printk() from calling console_flush_all()
while zonelist_update_seq.seqcount is odd.
Since Petr Mladek thinks that __build_all_zonelists() can become a
candidate for deferring printk() [2], let's address this problem by
disabling local interrupts in order to avoid kmalloc(GFP_ATOMIC)
and
disabling synchronous printk() in order to avoid console_flush_all()
.
As a side effect of minimizing duration of zonelist_update_seq.seqcount
being odd by disabling synchronous printk(), latency at
read_seqbegin(&zonelist_update_seq) for both !__GFP_DIRECT_RECLAIM and
__GFP_DIRECT_RECLAIM allocation requests will be reduced. Although, from
lockdep perspective, not calling read_seqbegin(&zonelist_update_seq) (i.e.
do not record unnecessary locking dependency) from interrupt context is
still preferable, even if we don't allow calling kmalloc(GFP_ATOMIC)
inside
write_seqlock(&zonelist_update_seq)/write_sequnlock(&zonelist_update_seq)
section...
Link: https://lkml.kernel.org/r/8796b95c-3da3-5885-fddd-6ef55f30e4d3@I-love.SAKURA.ne.jp
Fixes: 3d36424b3b ("mm/page_alloc: fix race condition between build_all_zonelists and page allocation")
Link: https://lkml.kernel.org/r/ZCrs+1cDqPWTDFNM@alley [2]
Reported-by: syzbot <syzbot+223c7461c58c58a4cb10@syzkaller.appspotmail.com>
Link: https://syzkaller.appspot.com/bug?extid=223c7461c58c58a4cb10 [1]
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Mel Gorman <mgorman@techsingularity.net>
Cc: Petr Mladek <pmladek@suse.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Cc: John Ogness <john.ogness@linutronix.de>
Cc: Patrick Daly <quic_pdaly@quicinc.com>
Cc: Sergey Senozhatsky <senozhatsky@chromium.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 4d73ba5fa7 upstream.
A bug was reported by Yuanxi Liu where allocating 1G pages at runtime is
taking an excessive amount of time for large amounts of memory. Further
testing allocating huge pages that the cost is linear i.e. if allocating
1G pages in batches of 10 then the time to allocate nr_hugepages from
10->20->30->etc increases linearly even though 10 pages are allocated at
each step. Profiles indicated that much of the time is spent checking the
validity within already existing huge pages and then attempting a
migration that fails after isolating the range, draining pages and a whole
lot of other useless work.
Commit eb14d4eefd ("mm,page_alloc: drop unnecessary checks from
pfn_range_valid_contig") removed two checks, one which ignored huge pages
for contiguous allocations as huge pages can sometimes migrate. While
there may be value on migrating a 2M page to satisfy a 1G allocation, it's
potentially expensive if the 1G allocation fails and it's pointless to try
moving a 1G page for a new 1G allocation or scan the tail pages for valid
PFNs.
Reintroduce the PageHuge check and assume any contiguous region with
hugetlbfs pages is unsuitable for a new 1G allocation.
The hpagealloc test allocates huge pages in batches and reports the
average latency per page over time. This test happens just after boot
when fragmentation is not an issue. Units are in milliseconds.
hpagealloc
6.3.0-rc6 6.3.0-rc6 6.3.0-rc6
vanilla hugeallocrevert-v1r1 hugeallocsimple-v1r2
Min Latency 26.42 ( 0.00%) 5.07 ( 80.82%) 18.94 ( 28.30%)
1st-qrtle Latency 356.61 ( 0.00%) 5.34 ( 98.50%) 19.85 ( 94.43%)
2nd-qrtle Latency 697.26 ( 0.00%) 5.47 ( 99.22%) 20.44 ( 97.07%)
3rd-qrtle Latency 972.94 ( 0.00%) 5.50 ( 99.43%) 20.81 ( 97.86%)
Max-1 Latency 26.42 ( 0.00%) 5.07 ( 80.82%) 18.94 ( 28.30%)
Max-5 Latency 82.14 ( 0.00%) 5.11 ( 93.78%) 19.31 ( 76.49%)
Max-10 Latency 150.54 ( 0.00%) 5.20 ( 96.55%) 19.43 ( 87.09%)
Max-90 Latency 1164.45 ( 0.00%) 5.53 ( 99.52%) 20.97 ( 98.20%)
Max-95 Latency 1223.06 ( 0.00%) 5.55 ( 99.55%) 21.06 ( 98.28%)
Max-99 Latency 1278.67 ( 0.00%) 5.57 ( 99.56%) 22.56 ( 98.24%)
Max Latency 1310.90 ( 0.00%) 8.06 ( 99.39%) 26.62 ( 97.97%)
Amean Latency 678.36 ( 0.00%) 5.44 * 99.20%* 20.44 * 96.99%*
6.3.0-rc6 6.3.0-rc6 6.3.0-rc6
vanilla revert-v1 hugeallocfix-v2
Duration User 0.28 0.27 0.30
Duration System 808.66 17.77 35.99
Duration Elapsed 830.87 18.08 36.33
The vanilla kernel is poor, taking up to 1.3 second to allocate a huge
page and almost 10 minutes in total to run the test. Reverting the
problematic commit reduces it to 8ms at worst and the patch takes 26ms.
This patch fixes the main issue with skipping huge pages but leaves the
page_count() out because a page with an elevated count potentially can
migrate.
BugLink: https://bugzilla.kernel.org/show_bug.cgi?id=217022
Link: https://lkml.kernel.org/r/20230414141429.pwgieuwluxwez3rj@techsingularity.net
Fixes: eb14d4eefd ("mm,page_alloc: drop unnecessary checks from pfn_range_valid_contig")
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Reported-by: Yuanxi Liu <y.liu@naruida.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: David Hildenbrand <david@redhat.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit dd47ac428c upstream.
Khugepaged collapse an anonymous thp in two rounds of scans. The 2nd
round done in __collapse_huge_page_isolate() after
hpage_collapse_scan_pmd(), during which all the locks will be released
temporarily. It means the pgtable can change during this phase before 2nd
round starts.
It's logically possible some ptes got wr-protected during this phase, and
we can errornously collapse a thp without noticing some ptes are
wr-protected by userfault. e1e267c792 wanted to avoid it but it only
did that for the 1st phase, not the 2nd phase.
Since __collapse_huge_page_isolate() happens after a round of small page
swapins, we don't need to worry on any !present ptes - if it existed
khugepaged will already bail out. So we only need to check present ptes
with uffd-wp bit set there.
This is something I found only but never had a reproducer, I thought it
was one caused a bug in Muhammad's recent pagemap new ioctl work, but it
turns out it's not the cause of that but an userspace bug. However this
seems to still be a real bug even with a very small race window, still
worth to have it fixed and copy stable.
Link: https://lkml.kernel.org/r/20230405155120.3608140-1-peterx@redhat.com
Fixes: e1e267c792 ("khugepaged: skip collapse if uffd-wp detected")
Signed-off-by: Peter Xu <peterx@redhat.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Yang Shi <shy828301@gmail.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Axel Rasmussen <axelrasmussen@google.com>
Cc: Mike Rapoport <rppt@linux.vnet.ibm.com>
Cc: Nadav Amit <nadav.amit@gmail.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 7c7b962938 upstream.
Device exclusive page table entries are used to prevent CPU access to a
page whilst it is being accessed from a device. Typically this is used to
implement atomic operations when the underlying bus does not support
atomic access. When a CPU thread encounters a device exclusive entry it
locks the page and restores the original entry after calling mmu notifiers
to signal drivers that exclusive access is no longer available.
The device exclusive entry holds a reference to the page making it safe to
access the struct page whilst the entry is present. However the fault
handling code does not hold the PTL when taking the page lock. This means
if there are multiple threads faulting concurrently on the device
exclusive entry one will remove the entry whilst others will wait on the
page lock without holding a reference.
This can lead to threads locking or waiting on a folio with a zero
refcount. Whilst mmap_lock prevents the pages getting freed via munmap()
they may still be freed by a migration. This leads to warnings such as
PAGE_FLAGS_CHECK_AT_FREE due to the page being locked when the refcount
drops to zero.
Fix this by trying to take a reference on the folio before locking it.
The code already checks the PTE under the PTL and aborts if the entry is
no longer there. It is also possible the folio has been unmapped, freed
and re-allocated allowing a reference to be taken on an unrelated folio.
This case is also detected by the PTE check and the folio is unlocked
without further changes.
Link: https://lkml.kernel.org/r/20230330012519.804116-1-apopple@nvidia.com
Fixes: b756a3b5e7 ("mm: device exclusive memory access")
Signed-off-by: Alistair Popple <apopple@nvidia.com>
Reviewed-by: Ralph Campbell <rcampbell@nvidia.com>
Reviewed-by: John Hubbard <jhubbard@nvidia.com>
Acked-by: David Hildenbrand <david@redhat.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 6fe7d6b992 upstream.
The si->lock must be held when deleting the si from the available list.
Otherwise, another thread can re-add the si to the available list, which
can lead to memory corruption. The only place we have found where this
happens is in the swapoff path. This case can be described as below:
core 0 core 1
swapoff
del_from_avail_list(si) waiting
try lock si->lock acquire swap_avail_lock
and re-add si into
swap_avail_head
acquire si->lock but missing si already being added again, and continuing
to clear SWP_WRITEOK, etc.
It can be easily found that a massive warning messages can be triggered
inside get_swap_pages() by some special cases, for example, we call
madvise(MADV_PAGEOUT) on blocks of touched memory concurrently, meanwhile,
run much swapon-swapoff operations (e.g. stress-ng-swap).
However, in the worst case, panic can be caused by the above scene. In
swapoff(), the memory used by si could be kept in swap_info[] after
turning off a swap. This means memory corruption will not be caused
immediately until allocated and reset for a new swap in the swapon path.
A panic message caused: (with CONFIG_PLIST_DEBUG enabled)
------------[ cut here ]------------
top: 00000000e58a3003, n: 0000000013e75cda, p: 000000008cd4451a
prev: 0000000035b1e58a, n: 000000008cd4451a, p: 000000002150ee8d
next: 000000008cd4451a, n: 000000008cd4451a, p: 000000008cd4451a
WARNING: CPU: 21 PID: 1843 at lib/plist.c:60 plist_check_prev_next_node+0x50/0x70
Modules linked in: rfkill(E) crct10dif_ce(E)...
CPU: 21 PID: 1843 Comm: stress-ng Kdump: ... 5.10.134+
Hardware name: Alibaba Cloud ECS, BIOS 0.0.0 02/06/2015
pstate: 60400005 (nZCv daif +PAN -UAO -TCO BTYPE=--)
pc : plist_check_prev_next_node+0x50/0x70
lr : plist_check_prev_next_node+0x50/0x70
sp : ffff0018009d3c30
x29: ffff0018009d3c40 x28: ffff800011b32a98
x27: 0000000000000000 x26: ffff001803908000
x25: ffff8000128ea088 x24: ffff800011b32a48
x23: 0000000000000028 x22: ffff001800875c00
x21: ffff800010f9e520 x20: ffff001800875c00
x19: ffff001800fdc6e0 x18: 0000000000000030
x17: 0000000000000000 x16: 0000000000000000
x15: 0736076307640766 x14: 0730073007380731
x13: 0736076307640766 x12: 0730073007380731
x11: 000000000004058d x10: 0000000085a85b76
x9 : ffff8000101436e4 x8 : ffff800011c8ce08
x7 : 0000000000000000 x6 : 0000000000000001
x5 : ffff0017df9ed338 x4 : 0000000000000001
x3 : ffff8017ce62a000 x2 : ffff0017df9ed340
x1 : 0000000000000000 x0 : 0000000000000000
Call trace:
plist_check_prev_next_node+0x50/0x70
plist_check_head+0x80/0xf0
plist_add+0x28/0x140
add_to_avail_list+0x9c/0xf0
_enable_swap_info+0x78/0xb4
__do_sys_swapon+0x918/0xa10
__arm64_sys_swapon+0x20/0x30
el0_svc_common+0x8c/0x220
do_el0_svc+0x2c/0x90
el0_svc+0x1c/0x30
el0_sync_handler+0xa8/0xb0
el0_sync+0x148/0x180
irq event stamp: 2082270
Now, si->lock locked before calling 'del_from_avail_list()' to make sure
other thread see the si had been deleted and SWP_WRITEOK cleared together,
will not reinsert again.
This problem exists in versions after stable 5.10.y.
Link: https://lkml.kernel.org/r/20230404154716.23058-1-rongwei.wang@linux.alibaba.com
Fixes: a2468cc9bf ("swap: choose swap device according to numa node")
Tested-by: Yongchen Yin <wb-yyc939293@alibaba-inc.com>
Signed-off-by: Rongwei Wang <rongwei.wang@linux.alibaba.com>
Cc: Bagas Sanjaya <bagasdotme@gmail.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Aaron Lu <aaron.lu@intel.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 1c86a188e0 upstream.
The variable kfence_metadata is initialized in kfence_init_pool(), then,
it is not initialized if kfence is disabled after booting. In this case,
kfence_metadata will be used (e.g. ->lock and ->state fields) without
initialization when reading /sys/kernel/debug/kfence/objects. There will
be a warning if you enable CONFIG_DEBUG_SPINLOCK. Fix it by creating
debugfs files when necessary.
Link: https://lkml.kernel.org/r/20230315034441.44321-1-songmuchun@bytedance.com
Fixes: 0ce20dd840 ("mm: add Kernel Electric-Fence infrastructure")
Signed-off-by: Muchun Song <songmuchun@bytedance.com>
Tested-by: Marco Elver <elver@google.com>
Reviewed-by: Marco Elver <elver@google.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Jann Horn <jannh@google.com>
Cc: SeongJae Park <sjpark@amazon.de>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 2e08ca1802 upstream.
Nathan reported that when building with GNU as and a version of clang that
defaults to DWARF5:
$ make -skj"$(nproc)" ARCH=riscv CROSS_COMPILE=riscv64-linux-gnu- \
LLVM=1 LLVM_IAS=0 O=build \
mrproper allmodconfig mm/kfence/kfence_test.o
/tmp/kfence_test-08a0a0.s: Assembler messages:
/tmp/kfence_test-08a0a0.s:14627: Error: non-constant .uleb128 is not supported
/tmp/kfence_test-08a0a0.s:14628: Error: non-constant .uleb128 is not supported
/tmp/kfence_test-08a0a0.s:14632: Error: non-constant .uleb128 is not supported
/tmp/kfence_test-08a0a0.s:14633: Error: non-constant .uleb128 is not supported
/tmp/kfence_test-08a0a0.s:14639: Error: non-constant .uleb128 is not supported
...
This is because `-g` defaults to the compiler debug info default. If the
assembler does not support some of the directives used, the above errors
occur. To fix, remove the explicit passing of `-g`.
All the test wants is that stack traces print valid function names, and
debug info is not required for that. (I currently cannot recall why I
added the explicit `-g`.)
Link: https://lkml.kernel.org/r/20230316224705.709984-1-elver@google.com
Fixes: bc8fbc5f30 ("kfence: add test suite")
Signed-off-by: Marco Elver <elver@google.com>
Reported-by: Nathan Chancellor <nathan@kernel.org>
Cc: Alexander Potapenko <glider@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 66a1c22b70 upstream.
sh/migor_defconfig:
mm/slab.c: In function ‘slab_memory_callback’:
mm/slab.c:1127:23: error: implicit declaration of function ‘init_cache_node_node’; did you mean ‘drain_cache_node_node’? [-Werror=implicit-function-declaration]
1127 | ret = init_cache_node_node(nid);
| ^~~~~~~~~~~~~~~~~~~~
| drain_cache_node_node
The #ifdef condition protecting the definition of init_cache_node_node()
no longer matches the conditions protecting the (multiple) users.
Fix this by syncing the conditions.
Fixes: 76af6a054d ("mm/migrate: add CPU hotplug to demotion #ifdef")
Reported-by: Randy Dunlap <rdunlap@infradead.org>
Link: https://lore.kernel.org/r/b5bdea22-ed2f-3187-6efe-0c72330270a4@infradead.org
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 81e506bec9 upstream.
Kernel build regression with LLVM was reported here:
https://lore.kernel.org/all/Y1GCYXGtEVZbcv%2F5@dev-arch.thelio-3990X/ with
commit f35b5d7d67 ("mm: align larger anonymous mappings on THP
boundaries"). And the commit f35b5d7d67 was reverted.
It turned out the regression is related with madvise(MADV_DONTNEED)
was used by ld.lld. But with none PMD_SIZE aligned parameter len.
trace-bpfcc captured:
531607 531732 ld.lld do_madvise.part.0 start: 0x7feca9000000, len: 0x7fb000, behavior: 0x4
531607 531793 ld.lld do_madvise.part.0 start: 0x7fec86a00000, len: 0x7fb000, behavior: 0x4
If the underneath physical page is THP, the madvise(MADV_DONTNEED) can
trigger split_queue_lock contention raised significantly. perf showed
following data:
14.85% 0.00% ld.lld [kernel.kallsyms] [k]
entry_SYSCALL_64_after_hwframe
11.52%
entry_SYSCALL_64_after_hwframe
do_syscall_64
__x64_sys_madvise
do_madvise.part.0
zap_page_range
unmap_single_vma
unmap_page_range
page_remove_rmap
deferred_split_huge_page
__lock_text_start
native_queued_spin_lock_slowpath
If THP can't be removed from rmap as whole THP, partial THP will be
removed from rmap by removing sub-pages from rmap. Even the THP head page
is added to deferred queue already, the split_queue_lock will be acquired
and check whether the THP head page is in the queue already. Thus, the
contention of split_queue_lock is raised.
Before acquire split_queue_lock, check and bail out early if the THP
head page is in the queue already. The checking without holding
split_queue_lock could race with deferred_split_scan, but it doesn't
impact the correctness here.
Test result of building kernel with ld.lld:
commit 7b5a0b664e (parent commit of f35b5d7d67):
time -f "\t%E real,\t%U user,\t%S sys" make LD=ld.lld -skj96 allmodconfig all
6:07.99 real, 26367.77 user, 5063.35 sys
commit f35b5d7d67:
time -f "\t%E real,\t%U user,\t%S sys" make LD=ld.lld -skj96 allmodconfig all
7:22.15 real, 26235.03 user, 12504.55 sys
commit f35b5d7d67 with the fixing patch:
time -f "\t%E real,\t%U user,\t%S sys" make LD=ld.lld -skj96 allmodconfig all
6:08.49 real, 26520.15 user, 5047.91 sys
Link: https://lkml.kernel.org/r/20221223135207.2275317-1-fengwei.yin@intel.com
Signed-off-by: Yin Fengwei <fengwei.yin@intel.com>
Tested-by: Nathan Chancellor <nathan@kernel.org>
Acked-by: David Rientjes <rientjes@google.com>
Reviewed-by: "Huang, Ying" <ying.huang@intel.com>
Cc: Feng Tang <feng.tang@intel.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Rik van Riel <riel@surriel.com>
Cc: Xing Zhengjun <zhengjun.xing@linux.intel.com>
Cc: Yang Shi <shy828301@gmail.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit da34a8484d upstream.
Charge moving mode in cgroup1 allows memory to follow tasks as they
migrate between cgroups. This is, and always has been, a questionable
thing to do - for several reasons.
First, it's expensive. Pages need to be identified, locked and isolated
from various MM operations, and reassigned, one by one.
Second, it's unreliable. Once pages are charged to a cgroup, there isn't
always a clear owner task anymore. Cache isn't moved at all, for example.
Mapped memory is moved - but if trylocking or isolating a page fails,
it's arbitrarily left behind. Frequent moving between domains may leave a
task's memory scattered all over the place.
Third, it isn't really needed. Launcher tasks can kick off workload tasks
directly in their target cgroup. Using dedicated per-workload groups
allows fine-grained policy adjustments - no need to move tasks and their
physical pages between control domains. The feature was never
forward-ported to cgroup2, and it hasn't been missed.
Despite it being a niche usecase, the maintenance overhead of supporting
it is enormous. Because pages are moved while they are live and subject
to various MM operations, the synchronization rules are complicated.
There are lock_page_memcg() in MM and FS code, which non-cgroup people
don't understand. In some cases we've been able to shift code and cgroup
API calls around such that we can rely on native locking as much as
possible. But that's fragile, and sometimes we need to hold MM locks for
longer than we otherwise would (pte lock e.g.).
Mark the feature deprecated. Hopefully we can remove it soon.
And backport into -stable kernels so that people who develop against
earlier kernels are warned about this deprecation as early as possible.
[akpm@linux-foundation.org: fix memory.rst underlining]
Link: https://lkml.kernel.org/r/Y5COd+qXwk/S+n8N@cmpxchg.org
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Shakeel Butt <shakeelb@google.com>
Acked-by: Hugh Dickins <hughd@google.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Muchun Song <songmuchun@bytedance.com>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 5956592ce3 upstream.
I was running traces of the read code against an RAID storage system to
understand why read requests were being misaligned against the underlying
RAID strips. I found that the page end offset calculation in
filemap_get_read_batch() was off by one.
When a read is submitted with end offset 1048575, then it calculates the
end page for read of 256 when it should be 255. "last_index" is the index
of the page beyond the end of the read and it should be skipped when get a
batch of pages for read in @filemap_get_read_batch().
The below simple patch fixes the problem. This code was introduced in
kernel 5.12.
Link: https://lkml.kernel.org/r/20230208022400.28962-1-coolqyj@163.com
Fixes: cbd59c48ae ("mm/filemap: use head pages in generic_file_buffered_read")
Signed-off-by: Qian Yingjin <qian@ddn.com>
Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 647037adca upstream.
This reverts commit 115d9d77bb.
The pages being freed by memblock_free_late() have already been
initialized, but if they are in the deferred init range,
__free_one_page() might access nearby uninitialized pages when trying to
coalesce buddies. This can, for example, trigger this BUG:
BUG: unable to handle page fault for address: ffffe964c02580c8
RIP: 0010:__list_del_entry_valid+0x3f/0x70
<TASK>
__free_one_page+0x139/0x410
__free_pages_ok+0x21d/0x450
memblock_free_late+0x8c/0xb9
efi_free_boot_services+0x16b/0x25c
efi_enter_virtual_mode+0x403/0x446
start_kernel+0x678/0x714
secondary_startup_64_no_verify+0xd2/0xdb
</TASK>
A proper fix will be more involved so revert this change for the time
being.
Fixes: 115d9d77bb ("mm: Always release pages to the buddy allocator in memblock_free_late().")
Signed-off-by: Aaron Thompson <dev@aaront.org>
Link: https://lore.kernel.org/r/20230207082151.1303-1-dev@aaront.org
Signed-off-by: Mike Rapoport (IBM) <rppt@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 462a8e08e0 upstream.
When we upgraded our kernel, we started seeing some page corruption like
the following consistently:
BUG: Bad page state in process ganesha.nfsd pfn:1304ca
page:0000000022261c55 refcount:0 mapcount:-128 mapping:0000000000000000 index:0x0 pfn:0x1304ca
flags: 0x17ffffc0000000()
raw: 0017ffffc0000000 ffff8a513ffd4c98 ffffeee24b35ec08 0000000000000000
raw: 0000000000000000 0000000000000001 00000000ffffff7f 0000000000000000
page dumped because: nonzero mapcount
CPU: 0 PID: 15567 Comm: ganesha.nfsd Kdump: loaded Tainted: P B O 5.10.158-1.nutanix.20221209.el7.x86_64 #1
Hardware name: VMware, Inc. VMware Virtual Platform/440BX Desktop Reference Platform, BIOS 6.00 04/05/2016
Call Trace:
dump_stack+0x74/0x96
bad_page.cold+0x63/0x94
check_new_page_bad+0x6d/0x80
rmqueue+0x46e/0x970
get_page_from_freelist+0xcb/0x3f0
? _cond_resched+0x19/0x40
__alloc_pages_nodemask+0x164/0x300
alloc_pages_current+0x87/0xf0
skb_page_frag_refill+0x84/0x110
...
Sometimes, it would also show up as corruption in the free list pointer
and cause crashes.
After bisecting the issue, we found the issue started from commit
e320d3012d ("mm/page_alloc.c: fix freeing non-compound pages"):
if (put_page_testzero(page))
free_the_page(page, order);
else if (!PageHead(page))
while (order-- > 0)
free_the_page(page + (1 << order), order);
So the problem is the check PageHead is racy because at this point we
already dropped our reference to the page. So even if we came in with
compound page, the page can already be freed and PageHead can return
false and we will end up freeing all the tail pages causing double free.
Fixes: e320d3012d ("mm/page_alloc.c: fix freeing non-compound pages")
Link: https://lore.kernel.org/lkml/BYAPR02MB448855960A9656EEA81141FC94D99@BYAPR02MB4488.namprd02.prod.outlook.com/
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: stable@vger.kernel.org
Signed-off-by: Chunwei Chen <david.chen@nutanix.com>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 73bdf65ea7 ]
migrate_pages/mempolicy semantics state that CAP_SYS_NICE is required to
move pages shared with another process to a different node. page_mapcount
> 1 is being used to determine if a hugetlb page is shared. However, a
hugetlb page will have a mapcount of 1 if mapped by multiple processes via
a shared PMD. As a result, hugetlb pages shared by multiple processes and
mapped with a shared PMD can be moved by a process without CAP_SYS_NICE.
To fix, check for a shared PMD if mapcount is 1. If a shared PMD is found
consider the page shared.
Link: https://lkml.kernel.org/r/20230126222721.222195-3-mike.kravetz@oracle.com
Fixes: e2d8cf4055 ("migrate: add hugepage migration code to migrate_pages()")
Signed-off-by: Mike Kravetz <mike.kravetz@oracle.com>
Acked-by: Peter Xu <peterx@redhat.com>
Acked-by: David Hildenbrand <david@redhat.com>
Cc: James Houghton <jthoughton@google.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Muchun Song <songmuchun@bytedance.com>
Cc: Naoya Horiguchi <naoya.horiguchi@linux.dev>
Cc: Vishal Moola (Oracle) <vishal.moola@gmail.com>
Cc: Yang Shi <shy828301@gmail.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 7ce82f4c3f ]
We might fail to isolate huge page due to e.g. the page is under
migration which cleared HPageMigratable. We should return errno in this
case rather than always return 1 which could confuse the user, i.e. the
caller might think all of the memory is migrated while the hugetlb page is
left behind. We make the prototype of isolate_huge_page consistent with
isolate_lru_page as suggested by Huang Ying and rename isolate_huge_page
to isolate_hugetlb as suggested by Muchun to improve the readability.
Link: https://lkml.kernel.org/r/20220530113016.16663-4-linmiaohe@huawei.com
Fixes: e8db67eb0d ("mm: migrate: move_pages() supports thp migration")
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Suggested-by: Huang Ying <ying.huang@intel.com>
Reported-by: kernel test robot <lkp@intel.com> (build error)
Cc: Alistair Popple <apopple@nvidia.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Christoph Lameter <cl@linux.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Muchun Song <songmuchun@bytedance.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Peter Xu <peterx@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Stable-dep-of: 73bdf65ea7 ("migrate: hugetlb: check for hugetlb shared PMD in node migration")
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit 7717fc1a12 upstream.
The softlockup still occurs in get_swap_pages() under memory pressure. 64
CPU cores, 64GB memory, and 28 zram devices, the disksize of each zram
device is 50MB with same priority as si. Use the stress-ng tool to
increase memory pressure, causing the system to oom frequently.
The plist_for_each_entry_safe() loops in get_swap_pages() could reach tens
of thousands of times to find available space (extreme case:
cond_resched() is not called in scan_swap_map_slots()). Let's add
cond_resched() into get_swap_pages() when failed to find available space
to avoid softlockup.
Link: https://lkml.kernel.org/r/20230128094757.1060525-1-xialonglong1@huawei.com
Signed-off-by: Longlong Xia <xialonglong1@huawei.com>
Reviewed-by: "Huang, Ying" <ying.huang@intel.com>
Cc: Chen Wandun <chenwandun@huawei.com>
Cc: Huang Ying <ying.huang@intel.com>
Cc: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: Nanyong Sun <sunnanyong@huawei.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 79cc1ba7ba upstream.
Several run-time checkers (KASAN, UBSAN, KFENCE, KCSAN, sched) roll
their own warnings, and each check "panic_on_warn". Consolidate this
into a single function so that future instrumentation can be added in
a single location.
Cc: Marco Elver <elver@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Juri Lelli <juri.lelli@redhat.com>
Cc: Vincent Guittot <vincent.guittot@linaro.org>
Cc: Dietmar Eggemann <dietmar.eggemann@arm.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Ben Segall <bsegall@google.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Daniel Bristot de Oliveira <bristot@redhat.com>
Cc: Valentin Schneider <vschneid@redhat.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Konovalov <andreyknvl@gmail.com>
Cc: Vincenzo Frascino <vincenzo.frascino@arm.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: David Gow <davidgow@google.com>
Cc: tangmeng <tangmeng@uniontech.com>
Cc: Jann Horn <jannh@google.com>
Cc: Shuah Khan <skhan@linuxfoundation.org>
Cc: Petr Mladek <pmladek@suse.com>
Cc: "Paul E. McKenney" <paulmck@kernel.org>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: "Guilherme G. Piccoli" <gpiccoli@igalia.com>
Cc: Tiezhu Yang <yangtiezhu@loongson.cn>
Cc: kasan-dev@googlegroups.com
Cc: linux-mm@kvack.org
Reviewed-by: Luis Chamberlain <mcgrof@kernel.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Marco Elver <elver@google.com>
Reviewed-by: Andrey Konovalov <andreyknvl@gmail.com>
Link: https://lore.kernel.org/r/20221117234328.594699-4-keescook@chromium.org
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit e7ce750037 upstream.
panic_on_warn is unset inside panic(), so no need to unset it before
calling panic() in end_report().
Link: https://lkml.kernel.org/r/1644324666-15947-6-git-send-email-yangtiezhu@loongson.cn
Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
Reviewed-by: Marco Elver <elver@google.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Baoquan He <bhe@redhat.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Xuefeng Li <lixuefeng@loongson.cn>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit ab0c3f1251 upstream.
uprobe_write_opcode() uses collapse_pte_mapped_thp() to restore huge pmd,
when removing a breakpoint from hugepage text: vma->anon_vma is always set
in that case, so undo the prohibition. And MADV_COLLAPSE ought to be able
to collapse some page tables in a vma which happens to have anon_vma set
from CoWing elsewhere.
Is anon_vma lock required? Almost not: if any page other than expected
subpage of the non-anon huge page is found in the page table, collapse is
aborted without making any change. However, it is possible that an anon
page was CoWed from this extent in another mm or vma, in which case a
concurrent lookup might look here: so keep it away while clearing pmd (but
perhaps we shall go back to using pmd_lock() there in future).
Note that collapse_pte_mapped_thp() is exceptional in freeing a page table
without having cleared its ptes: I'm uneasy about that, and had thought
pte_clear()ing appropriate; but exclusive i_mmap lock does fix the
problem, and we would have to move the mmu_notification if clearing those
ptes.
What this fixes is not a dangerous instability. But I suggest Cc stable
because uprobes "healing" has regressed in that way, so this should follow
8d3c106e19 into those stable releases where it was backported (and may
want adjustment there - I'll supply backports as needed).
Link: https://lkml.kernel.org/r/b740c9fb-edba-92ba-59fb-7a5592e5dfc@google.com
Fixes: 8d3c106e19 ("mm/khugepaged: take the right locks for page table retraction")
Signed-off-by: Hugh Dickins <hughd@google.com>
Acked-by: David Hildenbrand <david@redhat.com>
Cc: Jann Horn <jannh@google.com>
Cc: Yang Shi <shy828301@gmail.com>
Cc: Zach O'Keefe <zokeefe@google.com>
Cc: Song Liu <songliubraving@fb.com>
Cc: <stable@vger.kernel.org> [5.4+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit b30c14cd61 ]
PMD sharing can only be done in PUD_SIZE-aligned pieces of VMAs; however,
it is possible that HugeTLB VMAs are split without unsharing the PMDs
first.
Without this fix, it is possible to hit the uffd-wp-related WARN_ON_ONCE
in hugetlb_change_protection [1]. The key there is that
hugetlb_unshare_all_pmds will not attempt to unshare PMDs in
non-PUD_SIZE-aligned sections of the VMA.
It might seem ideal to unshare in hugetlb_vm_op_open, but we need to
unshare in both the new and old VMAs, so unsharing in hugetlb_vm_op_split
seems natural.
[1]: https://lore.kernel.org/linux-mm/CADrL8HVeOkj0QH5VZZbRzybNE8CG-tEGFshnA+bG9nMgcWtBSg@mail.gmail.com/
Link: https://lkml.kernel.org/r/20230104231910.1464197-1-jthoughton@google.com
Fixes: 6dfeaff93b ("hugetlb/userfaultfd: unshare all pmds for hugetlbfs when register wp")
Signed-off-by: James Houghton <jthoughton@google.com>
Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
Acked-by: Peter Xu <peterx@redhat.com>
Cc: Axel Rasmussen <axelrasmussen@google.com>
Cc: Muchun Song <songmuchun@bytedance.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 115d9d77bb ]
If CONFIG_DEFERRED_STRUCT_PAGE_INIT is enabled, memblock_free_pages()
only releases pages to the buddy allocator if they are not in the
deferred range. This is correct for free pages (as defined by
for_each_free_mem_pfn_range_in_zone()) because free pages in the
deferred range will be initialized and released as part of the deferred
init process. memblock_free_pages() is called by memblock_free_late(),
which is used to free reserved ranges after memblock_free_all() has
run. All pages in reserved ranges have been initialized at that point,
and accordingly, those pages are not touched by the deferred init
process. This means that currently, if the pages that
memblock_free_late() intends to release are in the deferred range, they
will never be released to the buddy allocator. They will forever be
reserved.
In addition, memblock_free_pages() calls kmsan_memblock_free_pages(),
which is also correct for free pages but is not correct for reserved
pages. KMSAN metadata for reserved pages is initialized by
kmsan_init_shadow(), which runs shortly before memblock_free_all().
For both of these reasons, memblock_free_pages() should only be called
for free pages, and memblock_free_late() should call __free_pages_core()
directly instead.
One case where this issue can occur in the wild is EFI boot on
x86_64. The x86 EFI code reserves all EFI boot services memory ranges
via memblock_reserve() and frees them later via memblock_free_late()
(efi_reserve_boot_services() and efi_free_boot_services(),
respectively). If any of those ranges happens to fall within the
deferred init range, the pages will not be released and that memory will
be unavailable.
For example, on an Amazon EC2 t3.micro VM (1 GB) booting via EFI:
v6.2-rc2:
# grep -E 'Node|spanned|present|managed' /proc/zoneinfo
Node 0, zone DMA
spanned 4095
present 3999
managed 3840
Node 0, zone DMA32
spanned 246652
present 245868
managed 178867
v6.2-rc2 + patch:
# grep -E 'Node|spanned|present|managed' /proc/zoneinfo
Node 0, zone DMA
spanned 4095
present 3999
managed 3840
Node 0, zone DMA32
spanned 246652
present 245868
managed 222816 # +43,949 pages
Fixes: 3a80a7fa79 ("mm: meminit: initialise a subset of struct pages if CONFIG_DEFERRED_STRUCT_PAGE_INIT is set")
Signed-off-by: Aaron Thompson <dev@aaront.org>
Link: https://lore.kernel.org/r/01010185892de53e-e379acfb-7044-4b24-b30a-e2657c1ba989-000000@us-west-2.amazonses.com
Signed-off-by: Mike Rapoport (IBM) <rppt@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit be21b32afe upstream.
Depending on the memory configuration, isolate_freepages_block() may scan
pages out of the target range and causes panic.
Panic can occur on systems with multiple zones in a single pageblock.
The reason it is rare is that it only happens in special
configurations. Depending on how many similar systems there are, it
may be a good idea to fix this problem for older kernels as well.
The problem is that pfn as argument of fast_isolate_around() could be out
of the target range. Therefore we should consider the case where pfn <
start_pfn, and also the case where end_pfn < pfn.
This problem should have been addressd by the commit 6e2b7044c1 ("mm,
compaction: make fast_isolate_freepages() stay within zone") but there was
an oversight.
Case1: pfn < start_pfn
<at memory compaction for node Y>
| node X's zone | node Y's zone
+-----------------+------------------------------...
pageblock ^ ^ ^
+-----------+-----------+-----------+-----------+...
^ ^ ^
^ ^ end_pfn
^ start_pfn = cc->zone->zone_start_pfn
pfn
<---------> scanned range by "Scan After"
Case2: end_pfn < pfn
<at memory compaction for node X>
| node X's zone | node Y's zone
+-----------------+------------------------------...
pageblock ^ ^ ^
+-----------+-----------+-----------+-----------+...
^ ^ ^
^ ^ pfn
^ end_pfn
start_pfn
<---------> scanned range by "Scan Before"
It seems that there is no good reason to skip nr_isolated pages just after
given pfn. So let perform simple scan from start to end instead of
dividing the scan into "Before" and "After".
Link: https://lkml.kernel.org/r/20221026112438.236336-1-a.naribayashi@fujitsu.com
Fixes: 6e2b7044c1 ("mm, compaction: make fast_isolate_freepages() stay within zone").
Signed-off-by: NARIBAYASHI Akira <a.naribayashi@fujitsu.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 4a7ba45b1a upstream.
memcg_write_event_control() accesses the dentry->d_name of the specified
control fd to route the write call. As a cgroup interface file can't be
renamed, it's safe to access d_name as long as the specified file is a
regular cgroup file. Also, as these cgroup interface files can't be
removed before the directory, it's safe to access the parent too.
Prior to 347c4a8747 ("memcg: remove cgroup_event->cft"), there was a
call to __file_cft() which verified that the specified file is a regular
cgroupfs file before further accesses. The cftype pointer returned from
__file_cft() was no longer necessary and the commit inadvertently dropped
the file type check with it allowing any file to slip through. With the
invarients broken, the d_name and parent accesses can now race against
renames and removals of arbitrary files and cause use-after-free's.
Fix the bug by resurrecting the file type check in __file_cft(). Now that
cgroupfs is implemented through kernfs, checking the file operations needs
to go through a layer of indirection. Instead, let's check the superblock
and dentry type.
Link: https://lkml.kernel.org/r/Y5FRm/cfcKPGzWwl@slm.duckdns.org
Fixes: 347c4a8747 ("memcg: remove cgroup_event->cft")
Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-by: Jann Horn <jannh@google.com>
Acked-by: Roman Gushchin <roman.gushchin@linux.dev>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Muchun Song <songmuchun@bytedance.com>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: <stable@vger.kernel.org> [3.14+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit f268f6cf87 upstream.
Any codepath that zaps page table entries must invoke MMU notifiers to
ensure that secondary MMUs (like KVM) don't keep accessing pages which
aren't mapped anymore. Secondary MMUs don't hold their own references to
pages that are mirrored over, so failing to notify them can lead to page
use-after-free.
I'm marking this as addressing an issue introduced in commit f3f0e1d215
("khugepaged: add support of collapse for tmpfs/shmem pages"), but most of
the security impact of this only came in commit 27e1f82731 ("khugepaged:
enable collapse pmd for pte-mapped THP"), which actually omitted flushes
for the removal of present PTEs, not just for the removal of empty page
tables.
Link: https://lkml.kernel.org/r/20221129154730.2274278-3-jannh@google.com
Link: https://lkml.kernel.org/r/20221128180252.1684965-3-jannh@google.com
Link: https://lkml.kernel.org/r/20221125213714.4115729-3-jannh@google.com
Fixes: f3f0e1d215 ("khugepaged: add support of collapse for tmpfs/shmem pages")
Signed-off-by: Jann Horn <jannh@google.com>
Acked-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Yang Shi <shy828301@gmail.com>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
[manual backport: this code was refactored from two copies into a common
helper between 5.15 and 6.0]
Signed-off-by: Jann Horn <jannh@google.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit 2ba99c5e08 upstream.
Since commit 70cbc3cc78 ("mm: gup: fix the fast GUP race against THP
collapse"), the lockless_pages_from_mm() fastpath rechecks the pmd_t to
ensure that the page table was not removed by khugepaged in between.
However, lockless_pages_from_mm() still requires that the page table is
not concurrently freed. Fix it by sending IPIs (if the architecture uses
semi-RCU-style page table freeing) before freeing/reusing page tables.
Link: https://lkml.kernel.org/r/20221129154730.2274278-2-jannh@google.com
Link: https://lkml.kernel.org/r/20221128180252.1684965-2-jannh@google.com
Link: https://lkml.kernel.org/r/20221125213714.4115729-2-jannh@google.com
Fixes: ba76149f47 ("thp: khugepaged")
Signed-off-by: Jann Horn <jannh@google.com>
Reviewed-by: Yang Shi <shy828301@gmail.com>
Acked-by: David Hildenbrand <david@redhat.com>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
[manual backport: two of the three places in khugepaged that can free
ptes were refactored into a common helper between 5.15 and 6.0]
Signed-off-by: Jann Horn <jannh@google.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit 8d3c106e19 upstream.
pagetable walks on address ranges mapped by VMAs can be done under the
mmap lock, the lock of an anon_vma attached to the VMA, or the lock of the
VMA's address_space. Only one of these needs to be held, and it does not
need to be held in exclusive mode.
Under those circumstances, the rules for concurrent access to page table
entries are:
- Terminal page table entries (entries that don't point to another page
table) can be arbitrarily changed under the page table lock, with the
exception that they always need to be consistent for
hardware page table walks and lockless_pages_from_mm().
This includes that they can be changed into non-terminal entries.
- Non-terminal page table entries (which point to another page table)
can not be modified; readers are allowed to READ_ONCE() an entry, verify
that it is non-terminal, and then assume that its value will stay as-is.
Retracting a page table involves modifying a non-terminal entry, so
page-table-level locks are insufficient to protect against concurrent page
table traversal; it requires taking all the higher-level locks under which
it is possible to start a page walk in the relevant range in exclusive
mode.
The collapse_huge_page() path for anonymous THP already follows this rule,
but the shmem/file THP path was getting it wrong, making it possible for
concurrent rmap-based operations to cause corruption.
Link: https://lkml.kernel.org/r/20221129154730.2274278-1-jannh@google.com
Link: https://lkml.kernel.org/r/20221128180252.1684965-1-jannh@google.com
Link: https://lkml.kernel.org/r/20221125213714.4115729-1-jannh@google.com
Fixes: 27e1f82731 ("khugepaged: enable collapse pmd for pte-mapped THP")
Signed-off-by: Jann Horn <jannh@google.com>
Reviewed-by: Yang Shi <shy828301@gmail.com>
Acked-by: David Hildenbrand <david@redhat.com>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
[manual backport: this code was refactored from two copies into a common
helper between 5.15 and 6.0]
Signed-off-by: Jann Horn <jannh@google.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 829ae0f81c ]
The issue is reported when removing memory through virtio_mem device. The
transparent huge page, experienced copy-on-write fault, is wrongly
regarded as pinned. The transparent huge page is escaped from being
isolated in isolate_migratepages_block(). The transparent huge page can't
be migrated and the corresponding memory block can't be put into offline
state.
Fix it by replacing page_mapcount() with total_mapcount(). With this, the
transparent huge page can be isolated and migrated, and the memory block
can be put into offline state. Besides, The page's refcount is increased
a bit earlier to avoid the page is released when the check is executed.
Link: https://lkml.kernel.org/r/20221124095523.31061-1-gshan@redhat.com
Fixes: 1da2f328fa ("mm,thp,compaction,cma: allow THP migration for CMA allocations")
Signed-off-by: Gavin Shan <gshan@redhat.com>
Reported-by: Zhenyu Zhang <zhenyzha@redhat.com>
Tested-by: Zhenyu Zhang <zhenyzha@redhat.com>
Suggested-by: David Hildenbrand <david@redhat.com>
Acked-by: David Hildenbrand <david@redhat.com>
Cc: Alistair Popple <apopple@nvidia.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: William Kucharski <william.kucharski@oracle.com>
Cc: Zi Yan <ziy@nvidia.com>
Cc: <stable@vger.kernel.org> [5.7+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 89f6c88a6a ]
__isolate_lru_page_prepare() conflates two unrelated functions, with the
flags to one disjoint from the flags to the other; and hides some of the
important checks outside of isolate_migratepages_block(), where the
sequence is better to be visible. It comes from the days of lumpy
reclaim, before compaction, when the combination made more sense.
Move what's needed by mm/compaction.c isolate_migratepages_block() inline
there, and what's needed by mm/vmscan.c isolate_lru_pages() inline there.
Shorten "isolate_mode" to "mode", so the sequence of conditions is easier
to read. Declare a "mapping" variable, to save one call to page_mapping()
(but not another: calling again after page is locked is necessary).
Simplify isolate_lru_pages() with a "move_to" list pointer.
Link: https://lkml.kernel.org/r/879d62a8-91cc-d3c6-fb3b-69768236df68@google.com
Signed-off-by: Hugh Dickins <hughd@google.com>
Acked-by: David Rientjes <rientjes@google.com>
Reviewed-by: Alex Shi <alexs@kernel.org>
Cc: Alexander Duyck <alexander.duyck@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Stable-dep-of: 829ae0f81c ("mm: migrate: fix THP's mapcount on isolation")
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit f53af4285d upstream.
During proactive reclaim, we sometimes observe severe overreclaim, with
several thousand times more pages reclaimed than requested.
This trace was obtained from shrink_lruvec() during such an instance:
prio:0 anon_cost:1141521 file_cost:7767
nr_reclaimed:4387406 nr_to_reclaim:1047 (or_factor:4190)
nr=[7161123 345 578 1111]
While he reclaimer requested 4M, vmscan reclaimed close to 16G, most of it
by swapping. These requests take over a minute, during which the write()
to memory.reclaim is unkillably stuck inside the kernel.
Digging into the source, this is caused by the proportional reclaim
bailout logic. This code tries to resolve a fundamental conflict: to
reclaim roughly what was requested, while also aging all LRUs fairly and
in accordance to their size, swappiness, refault rates etc. The way it
attempts fairness is that once the reclaim goal has been reached, it stops
scanning the LRUs with the smaller remaining scan targets, and adjusts the
remainder of the bigger LRUs according to how much of the smaller LRUs was
scanned. It then finishes scanning that remainder regardless of the
reclaim goal.
This works fine if priority levels are low and the LRU lists are
comparable in size. However, in this instance, the cgroup that is
targeted by proactive reclaim has almost no files left - they've already
been squeezed out by proactive reclaim earlier - and the remaining anon
pages are hot. Anon rotations cause the priority level to drop to 0,
which results in reclaim targeting all of anon (a lot) and all of file
(almost nothing). By the time reclaim decides to bail, it has scanned
most or all of the file target, and therefor must also scan most or all of
the enormous anon target. This target is thousands of times larger than
the reclaim goal, thus causing the overreclaim.
The bailout code hasn't changed in years, why is this failing now? The
most likely explanations are two other recent changes in anon reclaim:
1. Before the series starting with commit 5df741963d ("mm: fix LRU
balancing effect of new transparent huge pages"), the VM was
overall relatively reluctant to swap at all, even if swap was
configured. This means the LRU balancing code didn't come into play
as often as it does now, and mostly in high pressure situations
where pronounced swap activity wouldn't be as surprising.
2. For historic reasons, shrink_lruvec() loops on the scan targets of
all LRU lists except the active anon one, meaning it would bail if
the only remaining pages to scan were active anon - even if there
were a lot of them.
Before the series starting with commit ccc5dc6734 ("mm/vmscan:
make active/inactive ratio as 1:1 for anon lru"), most anon pages
would live on the active LRU; the inactive one would contain only a
handful of preselected reclaim candidates. After the series, anon
gets aged similarly to file, and the inactive list is the default
for new anon pages as well, making it often the much bigger list.
As a result, the VM is now more likely to actually finish large
anon targets than before.
Change the code such that only one SWAP_CLUSTER_MAX-sized nudge toward the
larger LRU lists is made before bailing out on a met reclaim goal.
This fixes the extreme overreclaim problem.
Fairness is more subtle and harder to evaluate. No obvious misbehavior
was observed on the test workload, in any case. Conceptually, fairness
should primarily be a cumulative effect from regular, lower priority
scans. Once the VM is in trouble and needs to escalate scan targets to
make forward progress, fairness needs to take a backseat. This is also
acknowledged by the myriad exceptions in get_scan_count(). This patch
makes fairness decrease gradually, as it keeps fairness work static over
increasing priority levels with growing scan targets. This should make
more sense - although we may have to re-visit the exact values.
Link: https://lkml.kernel.org/r/20220802162811.39216-1-hannes@cmpxchg.org
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Reviewed-by: Rik van Riel <riel@surriel.com>
Acked-by: Mel Gorman <mgorman@techsingularity.net>
Cc: Hugh Dickins <hughd@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 1468c6f455 upstream.
Functions implementing the a_ops->write_end() interface accept the `void
*fsdata` parameter that is supposed to be initialized by the corresponding
a_ops->write_begin() (which accepts `void **fsdata`).
However not all a_ops->write_begin() implementations initialize `fsdata`
unconditionally, so it may get passed uninitialized to a_ops->write_end(),
resulting in undefined behavior.
Fix this by initializing fsdata with NULL before the call to
write_begin(), rather than doing so in all possible a_ops implementations.
This patch covers only the following cases found by running x86 KMSAN
under syzkaller:
- generic_perform_write()
- cont_expand_zero() and generic_cont_expand_simple()
- page_symlink()
Other cases of passing uninitialized fsdata may persist in the codebase.
Link: https://lkml.kernel.org/r/20220915150417.722975-43-glider@google.com
Signed-off-by: Alexander Potapenko <glider@google.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Andrey Konovalov <andreyknvl@gmail.com>
Cc: Andrey Konovalov <andreyknvl@google.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Christoph Lameter <cl@linux.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Eric Biggers <ebiggers@google.com>
Cc: Eric Biggers <ebiggers@kernel.org>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Ilya Leoshkevich <iii@linux.ibm.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Marco Elver <elver@google.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Michael S. Tsirkin <mst@redhat.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Petr Mladek <pmladek@suse.com>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Vegard Nossum <vegard.nossum@oracle.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reuben Hawkins