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commit 1f737846aa3c45f07a06fa0d018b39e1afb8084a upstream.
In order to minimize code size (CONFIG_CC_OPTIMIZE_FOR_SIZE=y),
compiler might choose to make a regular function call (out-of-line) for
shmem_is_huge() instead of inlining it. When transparent hugepages are
disabled (CONFIG_TRANSPARENT_HUGEPAGE=n), it can cause compilation
error.
mm/shmem.c: In function `shmem_getattr':
./include/linux/huge_mm.h:383:27: note: in expansion of macro `BUILD_BUG'
383 | #define HPAGE_PMD_SIZE ({ BUILD_BUG(); 0; })
| ^~~~~~~~~
mm/shmem.c:1148:33: note: in expansion of macro `HPAGE_PMD_SIZE'
1148 | stat->blksize = HPAGE_PMD_SIZE;
To prevent the possible error, always inline shmem_is_huge() when
transparent hugepages are disabled.
Link: https://lkml.kernel.org/r/20240409155407.2322714-1-sumanthk@linux.ibm.com
Signed-off-by: Sumanth Korikkar <sumanthk@linux.ibm.com>
Acked-by: David Hildenbrand <david@redhat.com>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Ilya Leoshkevich <iii@linux.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit 1983184c22dd84a4d95a71e5c6775c2638557dc7 upstream.
When I did hard offline test with hugetlb pages, below deadlock occurs:
======================================================
WARNING: possible circular locking dependency detected
6.8.0-11409-gf6cef5f8c37f #1 Not tainted
------------------------------------------------------
bash/46904 is trying to acquire lock:
ffffffffabe68910 (cpu_hotplug_lock){++++}-{0:0}, at: static_key_slow_dec+0x16/0x60
but task is already holding lock:
ffffffffabf92ea8 (pcp_batch_high_lock){+.+.}-{3:3}, at: zone_pcp_disable+0x16/0x40
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> #1 (pcp_batch_high_lock){+.+.}-{3:3}:
__mutex_lock+0x6c/0x770
page_alloc_cpu_online+0x3c/0x70
cpuhp_invoke_callback+0x397/0x5f0
__cpuhp_invoke_callback_range+0x71/0xe0
_cpu_up+0xeb/0x210
cpu_up+0x91/0xe0
cpuhp_bringup_mask+0x49/0xb0
bringup_nonboot_cpus+0xb7/0xe0
smp_init+0x25/0xa0
kernel_init_freeable+0x15f/0x3e0
kernel_init+0x15/0x1b0
ret_from_fork+0x2f/0x50
ret_from_fork_asm+0x1a/0x30
-> #0 (cpu_hotplug_lock){++++}-{0:0}:
__lock_acquire+0x1298/0x1cd0
lock_acquire+0xc0/0x2b0
cpus_read_lock+0x2a/0xc0
static_key_slow_dec+0x16/0x60
__hugetlb_vmemmap_restore_folio+0x1b9/0x200
dissolve_free_huge_page+0x211/0x260
__page_handle_poison+0x45/0xc0
memory_failure+0x65e/0xc70
hard_offline_page_store+0x55/0xa0
kernfs_fop_write_iter+0x12c/0x1d0
vfs_write+0x387/0x550
ksys_write+0x64/0xe0
do_syscall_64+0xca/0x1e0
entry_SYSCALL_64_after_hwframe+0x6d/0x75
other info that might help us debug this:
Possible unsafe locking scenario:
CPU0 CPU1
---- ----
lock(pcp_batch_high_lock);
lock(cpu_hotplug_lock);
lock(pcp_batch_high_lock);
rlock(cpu_hotplug_lock);
*** DEADLOCK ***
5 locks held by bash/46904:
#0: ffff98f6c3bb23f0 (sb_writers#5){.+.+}-{0:0}, at: ksys_write+0x64/0xe0
#1: ffff98f6c328e488 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0xf8/0x1d0
#2: ffff98ef83b31890 (kn->active#113){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x100/0x1d0
#3: ffffffffabf9db48 (mf_mutex){+.+.}-{3:3}, at: memory_failure+0x44/0xc70
#4: ffffffffabf92ea8 (pcp_batch_high_lock){+.+.}-{3:3}, at: zone_pcp_disable+0x16/0x40
stack backtrace:
CPU: 10 PID: 46904 Comm: bash Kdump: loaded Not tainted 6.8.0-11409-gf6cef5f8c37f #1
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.14.0-0-g155821a1990b-prebuilt.qemu.org 04/01/2014
Call Trace:
<TASK>
dump_stack_lvl+0x68/0xa0
check_noncircular+0x129/0x140
__lock_acquire+0x1298/0x1cd0
lock_acquire+0xc0/0x2b0
cpus_read_lock+0x2a/0xc0
static_key_slow_dec+0x16/0x60
__hugetlb_vmemmap_restore_folio+0x1b9/0x200
dissolve_free_huge_page+0x211/0x260
__page_handle_poison+0x45/0xc0
memory_failure+0x65e/0xc70
hard_offline_page_store+0x55/0xa0
kernfs_fop_write_iter+0x12c/0x1d0
vfs_write+0x387/0x550
ksys_write+0x64/0xe0
do_syscall_64+0xca/0x1e0
entry_SYSCALL_64_after_hwframe+0x6d/0x75
RIP: 0033:0x7fc862314887
Code: 10 00 f7 d8 64 89 02 48 c7 c0 ff ff ff ff eb b7 0f 1f 00 f3 0f 1e fa 64 8b 04 25 18 00 00 00 85 c0 75 10 b8 01 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 51 c3 48 83 ec 28 48 89 54 24 18 48 89 74 24
RSP: 002b:00007fff19311268 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 000000000000000c RCX: 00007fc862314887
RDX: 000000000000000c RSI: 000056405645fe10 RDI: 0000000000000001
RBP: 000056405645fe10 R08: 00007fc8623d1460 R09: 000000007fffffff
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000000000c
R13: 00007fc86241b780 R14: 00007fc862417600 R15: 00007fc862416a00
In short, below scene breaks the lock dependency chain:
memory_failure
__page_handle_poison
zone_pcp_disable -- lock(pcp_batch_high_lock)
dissolve_free_huge_page
__hugetlb_vmemmap_restore_folio
static_key_slow_dec
cpus_read_lock -- rlock(cpu_hotplug_lock)
Fix this by calling drain_all_pages() instead.
This issue won't occur until commit a6b40850c442 ("mm: hugetlb: replace
hugetlb_free_vmemmap_enabled with a static_key"). As it introduced
rlock(cpu_hotplug_lock) in dissolve_free_huge_page() code path while
lock(pcp_batch_high_lock) is already in the __page_handle_poison().
[linmiaohe@huawei.com: extend comment per Oscar]
[akpm@linux-foundation.org: reflow block comment]
Link: https://lkml.kernel.org/r/20240407085456.2798193-1-linmiaohe@huawei.com
Fixes: a6b40850c442 ("mm: hugetlb: replace hugetlb_free_vmemmap_enabled with a static_key")
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Acked-by: Oscar Salvador <osalvador@suse.de>
Reviewed-by: Jane Chu <jane.chu@oracle.com>
Cc: Naoya Horiguchi <nao.horiguchi@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>
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commit c5977c95dff182d6ee06f4d6f60bcb0284912969 upstream.
After UFFDIO_POISON, there can be two kinds of hugetlb pte markers, either
the POISON one or UFFD_WP one.
Allow change protection to run on a poisoned marker just like !hugetlb
cases, ignoring the marker irrelevant of the permission.
Here the two bits are mutual exclusive. For example, when install a
poisoned entry it must not be UFFD_WP already (by checking pte_none()
before such install). And it also means if UFFD_WP is set there must have
no POISON bit set. It makes sense because UFFD_WP is a bit to reflect
permission, and permissions do not apply if the pte is poisoned and
destined to sigbus.
So here we simply check uffd_wp bit set first, do nothing otherwise.
Attach the Fixes to UFFDIO_POISON work, as before that it should not be
possible to have poison entry for hugetlb (e.g., hugetlb doesn't do swap,
so no chance of swapin errors).
Link: https://lkml.kernel.org/r/20240405231920.1772199-1-peterx@redhat.com
Link: https://lore.kernel.org/r/000000000000920d5e0615602dd1@google.com
Fixes: fc71884a5f59 ("mm: userfaultfd: add new UFFDIO_POISON ioctl")
Signed-off-by: Peter Xu <peterx@redhat.com>
Reported-by: syzbot+b07c8ac8eee3d4d8440f@syzkaller.appspotmail.com
Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Axel Rasmussen <axelrasmussen@google.com>
Cc: <stable@vger.kernel.org> [6.6+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit 631426ba1d45a8672b177ee85ad4cabe760dd131 upstream.
Darrick reports that in some cases where pread() would fail with -EIO and
mmap()+access would generate a SIGBUS signal, MADV_POPULATE_READ /
MADV_POPULATE_WRITE will keep retrying forever and not fail with -EFAULT.
While the madvise() call can be interrupted by a signal, this is not the
desired behavior. MADV_POPULATE_READ / MADV_POPULATE_WRITE should behave
like page faults in that case: fail and not retry forever.
A reproducer can be found at [1].
The reason is that __get_user_pages(), as called by
faultin_vma_page_range(), will not handle VM_FAULT_RETRY in a proper way:
it will simply return 0 when VM_FAULT_RETRY happened, making
madvise_populate()->faultin_vma_page_range() retry again and again, never
setting FOLL_TRIED->FAULT_FLAG_TRIED for __get_user_pages().
__get_user_pages_locked() does what we want, but duplicating that logic in
faultin_vma_page_range() feels wrong.
So let's use __get_user_pages_locked() instead, that will detect
VM_FAULT_RETRY and set FOLL_TRIED when retrying, making the fault handler
return VM_FAULT_SIGBUS (VM_FAULT_ERROR) at some point, propagating -EFAULT
from faultin_page() to __get_user_pages(), all the way to
madvise_populate().
But, there is an issue: __get_user_pages_locked() will end up re-taking
the MM lock and then __get_user_pages() will do another VMA lookup. In
the meantime, the VMA layout could have changed and we'd fail with
different error codes than we'd want to.
As __get_user_pages() will currently do a new VMA lookup either way, let
it do the VMA handling in a different way, controlled by a new
FOLL_MADV_POPULATE flag, effectively moving these checks from
madvise_populate() + faultin_page_range() in there.
With this change, Darricks reproducer properly fails with -EFAULT, as
documented for MADV_POPULATE_READ / MADV_POPULATE_WRITE.
[1] https://lore.kernel.org/all/20240313171936.GN1927156@frogsfrogsfrogs/
Link: https://lkml.kernel.org/r/20240314161300.382526-1-david@redhat.com
Link: https://lkml.kernel.org/r/20240314161300.382526-2-david@redhat.com
Fixes: 4ca9b3859dac ("mm/madvise: introduce MADV_POPULATE_(READ|WRITE) to prefault page tables")
Signed-off-by: David Hildenbrand <david@redhat.com>
Reported-by: Darrick J. Wong <djwong@kernel.org>
Closes: https://lore.kernel.org/all/20240311223815.GW1927156@frogsfrogsfrogs/
Cc: Darrick J. Wong <djwong@kernel.org>
Cc: Hugh Dickins <hughd@google.com>
Cc: Jason Gunthorpe <jgg@nvidia.com>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit c0205eaf3af9f5db14d4b5ee4abacf4a583c3c50 upstream.
Commit d7a08838ab74 ("mm: userfaultfd: fix unexpected change to src_folio
when UFFDIO_MOVE fails") moved the src_folio->{mapping, index} changing to
after clearing the page-table and ensuring that it's not pinned. This
avoids failure of swapout+migration and possibly memory corruption.
However, the commit missed fixing it in the huge-page case.
Link: https://lkml.kernel.org/r/20240404171726.2302435-1-lokeshgidra@google.com
Fixes: adef440691ba ("userfaultfd: UFFDIO_MOVE uABI")
Signed-off-by: Lokesh Gidra <lokeshgidra@google.com>
Acked-by: David Hildenbrand <david@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Kalesh Singh <kaleshsingh@google.com>
Cc: Lokesh Gidra <lokeshgidra@google.com>
Cc: Nicolas Geoffray <ngeoffray@google.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: Qi Zheng <zhengqi.arch@bytedance.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Lokesh Gidra <lokeshgidra@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit 04c35ab3bdae7fefbd7c7a7355f29fa03a035221 upstream.
PAT handling won't do the right thing in COW mappings: the first PTE (or,
in fact, all PTEs) can be replaced during write faults to point at anon
folios. Reliably recovering the correct PFN and cachemode using
follow_phys() from PTEs will not work in COW mappings.
Using follow_phys(), we might just get the address+protection of the anon
folio (which is very wrong), or fail on swap/nonswap entries, failing
follow_phys() and triggering a WARN_ON_ONCE() in untrack_pfn() and
track_pfn_copy(), not properly calling free_pfn_range().
In free_pfn_range(), we either wouldn't call memtype_free() or would call
it with the wrong range, possibly leaking memory.
To fix that, let's update follow_phys() to refuse returning anon folios,
and fallback to using the stored PFN inside vma->vm_pgoff for COW mappings
if we run into that.
We will now properly handle untrack_pfn() with COW mappings, where we
don't need the cachemode. We'll have to fail fork()->track_pfn_copy() if
the first page was replaced by an anon folio, though: we'd have to store
the cachemode in the VMA to make this work, likely growing the VMA size.
For now, lets keep it simple and let track_pfn_copy() just fail in that
case: it would have failed in the past with swap/nonswap entries already,
and it would have done the wrong thing with anon folios.
Simple reproducer to trigger the WARN_ON_ONCE() in untrack_pfn():
<--- C reproducer --->
#include <stdio.h>
#include <sys/mman.h>
#include <unistd.h>
#include <liburing.h>
int main(void)
{
struct io_uring_params p = {};
int ring_fd;
size_t size;
char *map;
ring_fd = io_uring_setup(1, &p);
if (ring_fd < 0) {
perror("io_uring_setup");
return 1;
}
size = p.sq_off.array + p.sq_entries * sizeof(unsigned);
/* Map the submission queue ring MAP_PRIVATE */
map = mmap(0, size, PROT_READ | PROT_WRITE, MAP_PRIVATE,
ring_fd, IORING_OFF_SQ_RING);
if (map == MAP_FAILED) {
perror("mmap");
return 1;
}
/* We have at least one page. Let's COW it. */
*map = 0;
pause();
return 0;
}
<--- C reproducer --->
On a system with 16 GiB RAM and swap configured:
# ./iouring &
# memhog 16G
# killall iouring
[ 301.552930] ------------[ cut here ]------------
[ 301.553285] WARNING: CPU: 7 PID: 1402 at arch/x86/mm/pat/memtype.c:1060 untrack_pfn+0xf4/0x100
[ 301.553989] Modules linked in: binfmt_misc nft_fib_inet nft_fib_ipv4 nft_fib_ipv6 nft_fib nft_reject_g
[ 301.558232] CPU: 7 PID: 1402 Comm: iouring Not tainted 6.7.5-100.fc38.x86_64 #1
[ 301.558772] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.16.3-0-ga6ed6b701f0a-prebu4
[ 301.559569] RIP: 0010:untrack_pfn+0xf4/0x100
[ 301.559893] Code: 75 c4 eb cf 48 8b 43 10 8b a8 e8 00 00 00 3b 6b 28 74 b8 48 8b 7b 30 e8 ea 1a f7 000
[ 301.561189] RSP: 0018:ffffba2c0377fab8 EFLAGS: 00010282
[ 301.561590] RAX: 00000000ffffffea RBX: ffff9208c8ce9cc0 RCX: 000000010455e047
[ 301.562105] RDX: 07fffffff0eb1e0a RSI: 0000000000000000 RDI: ffff9208c391d200
[ 301.562628] RBP: 0000000000000000 R08: ffffba2c0377fab8 R09: 0000000000000000
[ 301.563145] R10: ffff9208d2292d50 R11: 0000000000000002 R12: 00007fea890e0000
[ 301.563669] R13: 0000000000000000 R14: ffffba2c0377fc08 R15: 0000000000000000
[ 301.564186] FS: 0000000000000000(0000) GS:ffff920c2fbc0000(0000) knlGS:0000000000000000
[ 301.564773] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 301.565197] CR2: 00007fea88ee8a20 CR3: 00000001033a8000 CR4: 0000000000750ef0
[ 301.565725] PKRU: 55555554
[ 301.565944] Call Trace:
[ 301.566148] <TASK>
[ 301.566325] ? untrack_pfn+0xf4/0x100
[ 301.566618] ? __warn+0x81/0x130
[ 301.566876] ? untrack_pfn+0xf4/0x100
[ 301.567163] ? report_bug+0x171/0x1a0
[ 301.567466] ? handle_bug+0x3c/0x80
[ 301.567743] ? exc_invalid_op+0x17/0x70
[ 301.568038] ? asm_exc_invalid_op+0x1a/0x20
[ 301.568363] ? untrack_pfn+0xf4/0x100
[ 301.568660] ? untrack_pfn+0x65/0x100
[ 301.568947] unmap_single_vma+0xa6/0xe0
[ 301.569247] unmap_vmas+0xb5/0x190
[ 301.569532] exit_mmap+0xec/0x340
[ 301.569801] __mmput+0x3e/0x130
[ 301.570051] do_exit+0x305/0xaf0
...
Link: https://lkml.kernel.org/r/20240403212131.929421-3-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Reported-by: Wupeng Ma <mawupeng1@huawei.com>
Closes: https://lkml.kernel.org/r/20240227122814.3781907-1-mawupeng1@huawei.com
Fixes: b1a86e15dc03 ("x86, pat: remove the dependency on 'vm_pgoff' in track/untrack pfn vma routines")
Fixes: 5899329b1910 ("x86: PAT: implement track/untrack of pfnmap regions for x86 - v3")
Acked-by: Ingo Molnar <mingo@kernel.org>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Borislav Petkov <bp@alien8.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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[ Upstream commit c40845e3195d074b34f8f8e400e28c9403a06588 ]
The -Woverride-init warn about code that may be intentional or not,
but the inintentional ones tend to be real bugs, so there is a bit of
disagreement on whether this warning option should be enabled by default
and we have multiple settings in scripts/Makefile.extrawarn as well as
individual subsystems.
Older versions of clang only supported -Wno-initializer-overrides with
the same meaning as gcc's -Woverride-init, though all supported versions
now work with both. Because of this difference, an earlier cleanup of
mine accidentally turned the clang warning off for W=1 builds and only
left it on for W=2, while it's still enabled for gcc with W=1.
There is also one driver that only turns the warning off for newer
versions of gcc but not other compilers, and some but not all the
Makefiles still use a cc-disable-warning conditional that is no
longer needed with supported compilers here.
Address all of the above by removing the special cases for clang
and always turning the warning off unconditionally where it got
in the way, using the syntax that is supported by both compilers.
Fixes: 2cd3271b7a31 ("kbuild: avoid duplicate warning options")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Hamza Mahfooz <hamza.mahfooz@amd.com>
Acked-by: Jani Nikula <jani.nikula@intel.com>
Acked-by: Andrew Jeffery <andrew@codeconstruct.com.au>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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commit d5d39c707a4cf0bcc84680178677b97aa2cb2627 upstream.
When cachestat on shmem races with swapping and invalidation, there
are two possible bugs:
1) A swapin error can have resulted in a poisoned swap entry in the
shmem inode's xarray. Calling get_shadow_from_swap_cache() on it
will result in an out-of-bounds access to swapper_spaces[].
Validate the entry with non_swap_entry() before going further.
2) When we find a valid swap entry in the shmem's inode, the shadow
entry in the swapcache might not exist yet: swap IO is still in
progress and we're before __remove_mapping; swapin, invalidation,
or swapoff have removed the shadow from swapcache after we saw the
shmem swap entry.
This will send a NULL to workingset_test_recent(). The latter
purely operates on pointer bits, so it won't crash - node 0, memcg
ID 0, eviction timestamp 0, etc. are all valid inputs - but it's a
bogus test. In theory that could result in a false "recently
evicted" count.
Such a false positive wouldn't be the end of the world. But for
code clarity and (future) robustness, be explicit about this case.
Bail on get_shadow_from_swap_cache() returning NULL.
Link: https://lkml.kernel.org/r/20240315095556.GC581298@cmpxchg.org
Fixes: cf264e1329fb ("cachestat: implement cachestat syscall")
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Reported-by: Chengming Zhou <chengming.zhou@linux.dev> [Bug #1]
Reported-by: Jann Horn <jannh@google.com> [Bug #2]
Reviewed-by: Chengming Zhou <chengming.zhou@linux.dev>
Reviewed-by: Nhat Pham <nphamcs@gmail.com>
Cc: <stable@vger.kernel.org> [v6.5+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit 0a69b6b3a026543bc215ccc866d0aea5579e6ce2 upstream.
A syzkaller reproducer found a race while attempting to remove dquot
information from the rb tree.
Fetching the rb_tree root node must also be protected by the
dqopt->dqio_sem, otherwise, giving the right timing, shmem_release_dquot()
will trigger a warning because it couldn't find a node in the tree, when
the real reason was the root node changing before the search starts:
Thread 1 Thread 2
- shmem_release_dquot() - shmem_{acquire,release}_dquot()
- fetch ROOT - Fetch ROOT
- acquire dqio_sem
- wait dqio_sem
- do something, triger a tree rebalance
- release dqio_sem
- acquire dqio_sem
- start searching for the node, but
from the wrong location, missing
the node, and triggering a warning.
Link: https://lkml.kernel.org/r/20240320124011.398847-1-cem@kernel.org
Fixes: eafc474e2029 ("shmem: prepare shmem quota infrastructure")
Signed-off-by: Carlos Maiolino <cmaiolino@redhat.com>
Reported-by: Ubisectech Sirius <bugreport@ubisectech.com>
Reviewed-by: Jan Kara <jack@suse.cz>
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 30fb6a8d9e3378919f378f9bf561142b4a6d2637 upstream.
Kent forwards this bug report of zswap re-entering the block layer
from an IO request allocation and locking up:
[10264.128242] sysrq: Show Blocked State
[10264.128268] task:kworker/20:0H state:D stack:0 pid:143 tgid:143 ppid:2 flags:0x00004000
[10264.128271] Workqueue: bcachefs_io btree_write_submit [bcachefs]
[10264.128295] Call Trace:
[10264.128295] <TASK>
[10264.128297] __schedule+0x3e6/0x1520
[10264.128303] schedule+0x32/0xd0
[10264.128304] schedule_timeout+0x98/0x160
[10264.128308] io_schedule_timeout+0x50/0x80
[10264.128309] wait_for_completion_io_timeout+0x7f/0x180
[10264.128310] submit_bio_wait+0x78/0xb0
[10264.128313] swap_writepage_bdev_sync+0xf6/0x150
[10264.128317] zswap_writeback_entry+0xf2/0x180
[10264.128319] shrink_memcg_cb+0xe7/0x2f0
[10264.128322] __list_lru_walk_one+0xb9/0x1d0
[10264.128325] list_lru_walk_one+0x5d/0x90
[10264.128326] zswap_shrinker_scan+0xc4/0x130
[10264.128327] do_shrink_slab+0x13f/0x360
[10264.128328] shrink_slab+0x28e/0x3c0
[10264.128329] shrink_one+0x123/0x1b0
[10264.128331] shrink_node+0x97e/0xbc0
[10264.128332] do_try_to_free_pages+0xe7/0x5b0
[10264.128333] try_to_free_pages+0xe1/0x200
[10264.128334] __alloc_pages_slowpath.constprop.0+0x343/0xde0
[10264.128337] __alloc_pages+0x32d/0x350
[10264.128338] allocate_slab+0x400/0x460
[10264.128339] ___slab_alloc+0x40d/0xa40
[10264.128345] kmem_cache_alloc+0x2e7/0x330
[10264.128348] mempool_alloc+0x86/0x1b0
[10264.128349] bio_alloc_bioset+0x200/0x4f0
[10264.128352] bio_alloc_clone+0x23/0x60
[10264.128354] alloc_io+0x26/0xf0 [dm_mod 7e9e6b44df4927f93fb3e4b5c782767396f58382]
[10264.128361] dm_submit_bio+0xb8/0x580 [dm_mod 7e9e6b44df4927f93fb3e4b5c782767396f58382]
[10264.128366] __submit_bio+0xb0/0x170
[10264.128367] submit_bio_noacct_nocheck+0x159/0x370
[10264.128368] bch2_submit_wbio_replicas+0x21c/0x3a0 [bcachefs 85f1b9a7a824f272eff794653a06dde1a94439f2]
[10264.128391] btree_write_submit+0x1cf/0x220 [bcachefs 85f1b9a7a824f272eff794653a06dde1a94439f2]
[10264.128406] process_one_work+0x178/0x350
[10264.128408] worker_thread+0x30f/0x450
[10264.128409] kthread+0xe5/0x120
The zswap shrinker resumes the swap_writepage()s that were intercepted
by the zswap store. This will enter the block layer, and may even
enter the filesystem depending on the swap backing file.
Make it respect GFP_NOIO and GFP_NOFS.
Link: https://lore.kernel.org/linux-mm/rc4pk2r42oyvjo4dc62z6sovquyllq56i5cdgcaqbd7wy3hfzr@n4nbxido3fme/
Link: https://lkml.kernel.org/r/20240321182532.60000-1-hannes@cmpxchg.org
Fixes: b5ba474f3f51 ("zswap: shrink zswap pool based on memory pressure")
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Reported-by: Kent Overstreet <kent.overstreet@linux.dev>
Acked-by: Yosry Ahmed <yosryahmed@google.com>
Reported-by: Jérôme Poulin <jeromepoulin@gmail.com>
Reviewed-by: Nhat Pham <nphamcs@gmail.com>
Reviewed-by: Chengming Zhou <chengming.zhou@linux.dev>
Cc: stable@vger.kernel.org [v6.8]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
|
|
[ Upstream commit 82634d7e24271698e50a3ec811e5f50de790a65f ]
memtest failed to find bad memory when compiled with clang. So use
{WRITE,READ}_ONCE to access memory to avoid compiler over optimization.
Link: https://lkml.kernel.org/r/20240312080422.691222-1-qiang4.zhang@intel.com
Signed-off-by: Qiang Zhang <qiang4.zhang@intel.com>
Cc: Bill Wendling <morbo@google.com>
Cc: Justin Stitt <justinstitt@google.com>
Cc: Nathan Chancellor <nathan@kernel.org>
Cc: Nick Desaulniers <ndesaulniers@google.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 82b1c07a0af603e3c47b906c8e991dc96f01688e ]
There was previously a theoretical window where swapoff() could run and
teardown a swap_info_struct while a call to free_swap_and_cache() was
running in another thread. This could cause, amongst other bad
possibilities, swap_page_trans_huge_swapped() (called by
free_swap_and_cache()) to access the freed memory for swap_map.
This is a theoretical problem and I haven't been able to provoke it from a
test case. But there has been agreement based on code review that this is
possible (see link below).
Fix it by using get_swap_device()/put_swap_device(), which will stall
swapoff(). There was an extra check in _swap_info_get() to confirm that
the swap entry was not free. This isn't present in get_swap_device()
because it doesn't make sense in general due to the race between getting
the reference and swapoff. So I've added an equivalent check directly in
free_swap_and_cache().
Details of how to provoke one possible issue (thanks to David Hildenbrand
for deriving this):
--8<-----
__swap_entry_free() might be the last user and result in
"count == SWAP_HAS_CACHE".
swapoff->try_to_unuse() will stop as soon as soon as si->inuse_pages==0.
So the question is: could someone reclaim the folio and turn
si->inuse_pages==0, before we completed swap_page_trans_huge_swapped().
Imagine the following: 2 MiB folio in the swapcache. Only 2 subpages are
still references by swap entries.
Process 1 still references subpage 0 via swap entry.
Process 2 still references subpage 1 via swap entry.
Process 1 quits. Calls free_swap_and_cache().
-> count == SWAP_HAS_CACHE
[then, preempted in the hypervisor etc.]
Process 2 quits. Calls free_swap_and_cache().
-> count == SWAP_HAS_CACHE
Process 2 goes ahead, passes swap_page_trans_huge_swapped(), and calls
__try_to_reclaim_swap().
__try_to_reclaim_swap()->folio_free_swap()->delete_from_swap_cache()->
put_swap_folio()->free_swap_slot()->swapcache_free_entries()->
swap_entry_free()->swap_range_free()->
...
WRITE_ONCE(si->inuse_pages, si->inuse_pages - nr_entries);
What stops swapoff to succeed after process 2 reclaimed the swap cache
but before process1 finished its call to swap_page_trans_huge_swapped()?
--8<-----
Link: https://lkml.kernel.org/r/20240306140356.3974886-1-ryan.roberts@arm.com
Fixes: 7c00bafee87c ("mm/swap: free swap slots in batch")
Closes: https://lore.kernel.org/linux-mm/65a66eb9-41f8-4790-8db2-0c70ea15979f@redhat.com/
Signed-off-by: Ryan Roberts <ryan.roberts@arm.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: "Huang, Ying" <ying.huang@intel.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 e10aea105e9ed14b62a11844fec6aaa87c6935a3 ]
The out-of-bounds test allocates an object that is three bytes too short
in order to validate the bounds checking. Starting with gcc-14, this
causes a compile-time warning as gcc has grown smart enough to understand
the sizeof() logic:
mm/kasan/kasan_test.c: In function 'kmalloc_oob_16':
mm/kasan/kasan_test.c:443:14: error: allocation of insufficient size '13' for type 'struct <anonymous>' with size '16' [-Werror=alloc-size]
443 | ptr1 = kmalloc(sizeof(*ptr1) - 3, GFP_KERNEL);
| ^
Hide the actual computation behind a RELOC_HIDE() that ensures
the compiler misses the intentional bug.
Link: https://lkml.kernel.org/r/20240212111609.869266-1-arnd@kernel.org
Fixes: 3f15801cdc23 ("lib: add kasan test module")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Andrey Konovalov <andreyknvl@gmail.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Marco Elver <elver@google.com>
Cc: Vincenzo Frascino <vincenzo.frascino@arm.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
|
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[ Upstream commit ccb49011bb2ebfd66164dbf68c5bff48917bb5ef ]
Dquots pointed to from i_dquot arrays in inodes are protected by
dquot_srcu. Annotate them as such and change .get_dquots callback to
return properly annotated pointer to make sparse happy.
Fixes: b9ba6f94b238 ("quota: remove dqptr_sem")
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Sasha Levin <sashal@kernel.org>
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Pull misc fixes from Andrew Morton:
"6 hotfixes. 4 are cc:stable and the remainder pertain to post-6.7
issues or aren't considered to be needed in earlier kernel versions"
* tag 'mm-hotfixes-stable-2024-03-07-16-17' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm:
scripts/gdb/symbols: fix invalid escape sequence warning
mailmap: fix Kishon's email
init/Kconfig: lower GCC version check for -Warray-bounds
mm, mmap: fix vma_merge() case 7 with vma_ops->close
mm: userfaultfd: fix unexpected change to src_folio when UFFDIO_MOVE fails
mm, vmscan: prevent infinite loop for costly GFP_NOIO | __GFP_RETRY_MAYFAIL allocations
|
|
When debugging issues with a workload using SysV shmem, Michal Hocko has
come up with a reproducer that shows how a series of mprotect() operations
can result in an elevated shm_nattch and thus leak of the resource.
The problem is caused by wrong assumptions in vma_merge() commit
714965ca8252 ("mm/mmap: start distinguishing if vma can be removed in
mergeability test"). The shmem vmas have a vma_ops->close callback that
decrements shm_nattch, and we remove the vma without calling it.
vma_merge() has thus historically avoided merging vma's with
vma_ops->close and commit 714965ca8252 was supposed to keep it that way.
It relaxed the checks for vma_ops->close in can_vma_merge_after() assuming
that it is never called on a vma that would be a candidate for removal.
However, the vma_merge() code does also use the result of this check in
the decision to remove a different vma in the merge case 7.
A robust solution would be to refactor vma_merge() code in a way that the
vma_ops->close check is only done for vma's that are actually going to be
removed, and not as part of the preliminary checks. That would both solve
the existing bug, and also allow additional merges that the checks
currently prevent unnecessarily in some cases.
However to fix the existing bug first with a minimized risk, and for
easier stable backports, this patch only adds a vma_ops->close check to
the buggy case 7 specifically. All other cases of vma removal are covered
by the can_vma_merge_before() check that includes the test for
vma_ops->close.
The reproducer code, adapted from Michal Hocko's code:
int main(int argc, char *argv[]) {
int segment_id;
size_t segment_size = 20 * PAGE_SIZE;
char * sh_mem;
struct shmid_ds shmid_ds;
key_t key = 0x1234;
segment_id = shmget(key, segment_size,
IPC_CREAT | IPC_EXCL | S_IRUSR | S_IWUSR);
sh_mem = (char *)shmat(segment_id, NULL, 0);
mprotect(sh_mem + 2*PAGE_SIZE, PAGE_SIZE, PROT_NONE);
mprotect(sh_mem + PAGE_SIZE, PAGE_SIZE, PROT_WRITE);
mprotect(sh_mem + 2*PAGE_SIZE, PAGE_SIZE, PROT_WRITE);
shmdt(sh_mem);
shmctl(segment_id, IPC_STAT, &shmid_ds);
printf("nattch after shmdt(): %lu (expected: 0)\n", shmid_ds.shm_nattch);
if (shmctl(segment_id, IPC_RMID, 0))
printf("IPCRM failed %d\n", errno);
return (shmid_ds.shm_nattch) ? 1 : 0;
}
Link: https://lkml.kernel.org/r/20240222215930.14637-2-vbabka@suse.cz
Fixes: 714965ca8252 ("mm/mmap: start distinguishing if vma can be removed in mergeability test")
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Reported-by: Michal Hocko <mhocko@suse.com>
Reviewed-by: Lorenzo Stoakes <lstoakes@gmail.com>
Reviewed-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
After ptep_clear_flush(), if we find that src_folio is pinned we will fail
UFFDIO_MOVE and put src_folio back to src_pte entry, but the change to
src_folio->{mapping,index} is not restored in this process. This is not
what we expected, so fix it.
This can cause the rmap for that page to be invalid, possibly resulting
in memory corruption. At least swapout+migration would no longer work,
because we might fail to locate the mappings of that folio.
Link: https://lkml.kernel.org/r/20240222080815.46291-1-zhengqi.arch@bytedance.com
Fixes: adef440691ba ("userfaultfd: UFFDIO_MOVE uABI")
Signed-off-by: Qi Zheng <zhengqi.arch@bytedance.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Suren Baghdasaryan <surenb@google.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
allocations
Sven reports an infinite loop in __alloc_pages_slowpath() for costly order
__GFP_RETRY_MAYFAIL allocations that are also GFP_NOIO. Such combination
can happen in a suspend/resume context where a GFP_KERNEL allocation can
have __GFP_IO masked out via gfp_allowed_mask.
Quoting Sven:
1. try to do a "costly" allocation (order > PAGE_ALLOC_COSTLY_ORDER)
with __GFP_RETRY_MAYFAIL set.
2. page alloc's __alloc_pages_slowpath tries to get a page from the
freelist. This fails because there is nothing free of that costly
order.
3. page alloc tries to reclaim by calling __alloc_pages_direct_reclaim,
which bails out because a zone is ready to be compacted; it pretends
to have made a single page of progress.
4. page alloc tries to compact, but this always bails out early because
__GFP_IO is not set (it's not passed by the snd allocator, and even
if it were, we are suspending so the __GFP_IO flag would be cleared
anyway).
5. page alloc believes reclaim progress was made (because of the
pretense in item 3) and so it checks whether it should retry
compaction. The compaction retry logic thinks it should try again,
because:
a) reclaim is needed because of the early bail-out in item 4
b) a zonelist is suitable for compaction
6. goto 2. indefinite stall.
(end quote)
The immediate root cause is confusing the COMPACT_SKIPPED returned from
__alloc_pages_direct_compact() (step 4) due to lack of __GFP_IO to be
indicating a lack of order-0 pages, and in step 5 evaluating that in
should_compact_retry() as a reason to retry, before incrementing and
limiting the number of retries. There are however other places that
wrongly assume that compaction can happen while we lack __GFP_IO.
To fix this, introduce gfp_compaction_allowed() to abstract the __GFP_IO
evaluation and switch the open-coded test in try_to_compact_pages() to use
it.
Also use the new helper in:
- compaction_ready(), which will make reclaim not bail out in step 3, so
there's at least one attempt to actually reclaim, even if chances are
small for a costly order
- in_reclaim_compaction() which will make should_continue_reclaim()
return false and we don't over-reclaim unnecessarily
- in __alloc_pages_slowpath() to set a local variable can_compact,
which is then used to avoid retrying reclaim/compaction for costly
allocations (step 5) if we can't compact and also to skip the early
compaction attempt that we do in some cases
Link: https://lkml.kernel.org/r/20240221114357.13655-2-vbabka@suse.cz
Fixes: 3250845d0526 ("Revert "mm, oom: prevent premature OOM killer invocation for high order request"")
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Reported-by: Sven van Ashbrook <svenva@chromium.org>
Closes: https://lore.kernel.org/all/CAG-rBihs_xMKb3wrMO1%2B-%2Bp4fowP9oy1pa_OTkfxBzPUVOZF%2Bg@mail.gmail.com/
Tested-by: Karthikeyan Ramasubramanian <kramasub@chromium.org>
Cc: Brian Geffon <bgeffon@google.com>
Cc: Curtis Malainey <cujomalainey@chromium.org>
Cc: Jaroslav Kysela <perex@perex.cz>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Takashi Iwai <tiwai@suse.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Pull misc fixes from Andrew Morton:
"Six hotfixes. Three are cc:stable and the remainder address post-6.7
issues or aren't considered appropriate for backporting"
* tag 'mm-hotfixes-stable-2024-02-27-14-52' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm:
mm/debug_vm_pgtable: fix BUG_ON with pud advanced test
mm: cachestat: fix folio read-after-free in cache walk
MAINTAINERS: add memory mapping entry with reviewers
mm/vmscan: fix a bug calling wakeup_kswapd() with a wrong zone index
kasan: revert eviction of stack traces in generic mode
stackdepot: use variable size records for non-evictable entries
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/cxl/cxl
Pull cxl fixes from Dan Williams:
"A collection of significant fixes for the CXL subsystem.
The largest change in this set, that bordered on "new development", is
the fix for the fact that the location of the new qos_class attribute
did not match the Documentation. The fix ends up deleting more code
than it added, and it has a new unit test to backstop basic errors in
this interface going forward. So the "red-diff" and unit test saved
the "rip it out and try again" response.
In contrast, the new notification path for firmware reported CXL
errors (CXL CPER notifications) has a locking context bug that can not
be fixed with a red-diff. Given where the release cycle stands, it is
not comfortable to squeeze in that fix in these waning days. So, that
receives the "back it out and try again later" treatment.
There is a regression fix in the code that establishes memory NUMA
nodes for platform CXL regions. That has an ack from x86 folks. There
are a couple more fixups for Linux to understand (reassemble) CXL
regions instantiated by platform firmware. The policy around platforms
that do not match host-physical-address with system-physical-address
(i.e. systems that have an address translation mechanism between the
address range reported in the ACPI CEDT.CFMWS and endpoint decoders)
has been softened to abort driver load rather than teardown the memory
range (can cause system hangs). Lastly, there is a robustness /
regression fix for cases where the driver would previously continue in
the face of error, and a fixup for PCI error notification handling.
Summary:
- Fix NUMA initialization from ACPI CEDT.CFMWS
- Fix region assembly failures due to async init order
- Fix / simplify export of qos_class information
- Fix cxl_acpi initialization vs single-window-init failures
- Fix handling of repeated 'pci_channel_io_frozen' notifications
- Workaround platforms that violate host-physical-address ==
system-physical address assumptions
- Defer CXL CPER notification handling to v6.9"
* tag 'cxl-fixes-6.8-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/cxl/cxl:
cxl/acpi: Fix load failures due to single window creation failure
acpi/ghes: Remove CXL CPER notifications
cxl/pci: Fix disabling memory if DVSEC CXL Range does not match a CFMWS window
cxl/test: Add support for qos_class checking
cxl: Fix sysfs export of qos_class for memdev
cxl: Remove unnecessary type cast in cxl_qos_class_verify()
cxl: Change 'struct cxl_memdev_state' *_perf_list to single 'struct cxl_dpa_perf'
cxl/region: Allow out of order assembly of autodiscovered regions
cxl/region: Handle endpoint decoders in cxl_region_find_decoder()
x86/numa: Fix the sort compare func used in numa_fill_memblks()
x86/numa: Fix the address overlap check in numa_fill_memblks()
cxl/pci: Skip to handle RAS errors if CXL.mem device is detached
|
|
Architectures like powerpc add debug checks to ensure we find only devmap
PUD pte entries. These debug checks are only done with CONFIG_DEBUG_VM.
This patch marks the ptes used for PUD advanced test devmap pte entries so
that we don't hit on debug checks on architecture like ppc64 as below.
WARNING: CPU: 2 PID: 1 at arch/powerpc/mm/book3s64/radix_pgtable.c:1382 radix__pud_hugepage_update+0x38/0x138
....
NIP [c0000000000a7004] radix__pud_hugepage_update+0x38/0x138
LR [c0000000000a77a8] radix__pudp_huge_get_and_clear+0x28/0x60
Call Trace:
[c000000004a2f950] [c000000004a2f9a0] 0xc000000004a2f9a0 (unreliable)
[c000000004a2f980] [000d34c100000000] 0xd34c100000000
[c000000004a2f9a0] [c00000000206ba98] pud_advanced_tests+0x118/0x334
[c000000004a2fa40] [c00000000206db34] debug_vm_pgtable+0xcbc/0x1c48
[c000000004a2fc10] [c00000000000fd28] do_one_initcall+0x60/0x388
Also
kernel BUG at arch/powerpc/mm/book3s64/pgtable.c:202!
....
NIP [c000000000096510] pudp_huge_get_and_clear_full+0x98/0x174
LR [c00000000206bb34] pud_advanced_tests+0x1b4/0x334
Call Trace:
[c000000004a2f950] [000d34c100000000] 0xd34c100000000 (unreliable)
[c000000004a2f9a0] [c00000000206bb34] pud_advanced_tests+0x1b4/0x334
[c000000004a2fa40] [c00000000206db34] debug_vm_pgtable+0xcbc/0x1c48
[c000000004a2fc10] [c00000000000fd28] do_one_initcall+0x60/0x388
Link: https://lkml.kernel.org/r/20240129060022.68044-1-aneesh.kumar@kernel.org
Fixes: 27af67f35631 ("powerpc/book3s64/mm: enable transparent pud hugepage")
Signed-off-by: Aneesh Kumar K.V (IBM) <aneesh.kumar@kernel.org>
Cc: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
In cachestat, we access the folio from the page cache's xarray to compute
its page offset, and check for its dirty and writeback flags. However, we
do not hold a reference to the folio before performing these actions,
which means the folio can concurrently be released and reused as another
folio/page/slab.
Get around this altogether by just using xarray's existing machinery for
the folio page offsets and dirty/writeback states.
This changes behavior for tmpfs files to now always report zeroes in their
dirty and writeback counters. This is okay as tmpfs doesn't follow
conventional writeback cache behavior: its pages get "cleaned" during
swapout, after which they're no longer resident etc.
Link: https://lkml.kernel.org/r/20240220153409.GA216065@cmpxchg.org
Fixes: cf264e1329fb ("cachestat: implement cachestat syscall")
Reported-by: Jann Horn <jannh@google.com>
Suggested-by: Matthew Wilcox <willy@infradead.org>
Signed-off-by: Nhat Pham <nphamcs@gmail.com>
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Tested-by: Jann Horn <jannh@google.com>
Cc: <stable@vger.kernel.org> [6.4+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
With numa balancing on, when a numa system is running where a numa node
doesn't have its local memory so it has no managed zones, the following
oops has been observed. It's because wakeup_kswapd() is called with a
wrong zone index, -1. Fixed it by checking the index before calling
wakeup_kswapd().
> BUG: unable to handle page fault for address: 00000000000033f3
> #PF: supervisor read access in kernel mode
> #PF: error_code(0x0000) - not-present page
> PGD 0 P4D 0
> Oops: 0000 [#1] PREEMPT SMP NOPTI
> CPU: 2 PID: 895 Comm: masim Not tainted 6.6.0-dirty #255
> Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS
> rel-1.16.0-0-gd239552ce722-prebuilt.qemu.org 04/01/2014
> RIP: 0010:wakeup_kswapd (./linux/mm/vmscan.c:7812)
> Code: (omitted)
> RSP: 0000:ffffc90004257d58 EFLAGS: 00010286
> RAX: ffffffffffffffff RBX: ffff88883fff0480 RCX: 0000000000000003
> RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff88883fff0480
> RBP: ffffffffffffffff R08: ff0003ffffffffff R09: ffffffffffffffff
> R10: ffff888106c95540 R11: 0000000055555554 R12: 0000000000000003
> R13: 0000000000000000 R14: 0000000000000000 R15: ffff88883fff0940
> FS: 00007fc4b8124740(0000) GS:ffff888827c00000(0000) knlGS:0000000000000000
> CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> CR2: 00000000000033f3 CR3: 000000026cc08004 CR4: 0000000000770ee0
> DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
> DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
> PKRU: 55555554
> Call Trace:
> <TASK>
> ? __die
> ? page_fault_oops
> ? __pte_offset_map_lock
> ? exc_page_fault
> ? asm_exc_page_fault
> ? wakeup_kswapd
> migrate_misplaced_page
> __handle_mm_fault
> handle_mm_fault
> do_user_addr_fault
> exc_page_fault
> asm_exc_page_fault
> RIP: 0033:0x55b897ba0808
> Code: (omitted)
> RSP: 002b:00007ffeefa821a0 EFLAGS: 00010287
> RAX: 000055b89983acd0 RBX: 00007ffeefa823f8 RCX: 000055b89983acd0
> RDX: 00007fc2f8122010 RSI: 0000000000020000 RDI: 000055b89983acd0
> RBP: 00007ffeefa821a0 R08: 0000000000000037 R09: 0000000000000075
> R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000000
> R13: 00007ffeefa82410 R14: 000055b897ba5dd8 R15: 00007fc4b8340000
> </TASK>
Link: https://lkml.kernel.org/r/20240216111502.79759-1-byungchul@sk.com
Signed-off-by: Byungchul Park <byungchul@sk.com>
Reported-by: Hyeongtak Ji <hyeongtak.ji@sk.com>
Fixes: c574bbe917036 ("NUMA balancing: optimize page placement for memory tiering system")
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: "Huang, Ying" <ying.huang@intel.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
This partially reverts commits cc478e0b6bdf, 63b85ac56a64, 08d7c94d9635,
a414d4286f34, and 773688a6cb24 to make use of variable-sized stack depot
records, since eviction of stack entries from stack depot forces fixed-
sized stack records. Care was taken to retain the code cleanups by the
above commits.
Eviction was added to generic KASAN as a response to alleviating the
additional memory usage from fixed-sized stack records, but this still
uses more memory than previously.
With the re-introduction of variable-sized records for stack depot, we can
just switch back to non-evictable stack records again, and return back to
the previous performance and memory usage baseline.
Before (observed after a KASAN kernel boot):
pools: 597
refcounted_allocations: 17547
refcounted_frees: 6477
refcounted_in_use: 11070
freelist_size: 3497
persistent_count: 12163
persistent_bytes: 1717008
After:
pools: 319
refcounted_allocations: 0
refcounted_frees: 0
refcounted_in_use: 0
freelist_size: 0
persistent_count: 29397
persistent_bytes: 5183536
As can be seen from the counters, with a generic KASAN config, refcounted
allocations and evictions are no longer used. Due to using variable-sized
records, I observe a reduction of 278 stack depot pools (saving 4448 KiB)
with my test setup.
Link: https://lkml.kernel.org/r/20240129100708.39460-2-elver@google.com
Fixes: cc478e0b6bdf ("kasan: avoid resetting aux_lock")
Fixes: 63b85ac56a64 ("kasan: stop leaking stack trace handles")
Fixes: 08d7c94d9635 ("kasan: memset free track in qlink_free")
Fixes: a414d4286f34 ("kasan: handle concurrent kasan_record_aux_stack calls")
Fixes: 773688a6cb24 ("kasan: use stack_depot_put for Generic mode")
Signed-off-by: Marco Elver <elver@google.com>
Reviewed-by: Andrey Konovalov <andreyknvl@gmail.com>
Tested-by: Mikhail Gavrilov <mikhail.v.gavrilov@gmail.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Vincenzo Frascino <vincenzo.frascino@arm.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
Pick up CXL CPER notification removal for v6.8-rc6, to return in a later
merge window.
|
|
release_free_meta() accesses the shadow directly through the path
kasan_slab_free
__kasan_slab_free
kasan_release_object_meta
release_free_meta
kasan_mem_to_shadow
There are no kasan_arch_is_ready() guards here, allowing an oops when the
shadow is not initialized. The oops can be seen on a Power8 KVM guest.
This patch adds the guard to release_free_meta(), as it's the first level
that specifically requires the shadow.
It is safe to put the guard at the start of this function, before the
stack put: only kasan_save_free_info() can initialize the saved stack,
which itself is guarded with kasan_arch_is_ready() by its caller
poison_slab_object(). If the arch becomes ready before
release_free_meta() then we will not observe KASAN_SLAB_FREE_META in the
object's shadow, so we will not put an uninitialized stack either.
Link: https://lkml.kernel.org/r/20240213033958.139383-1-bgray@linux.ibm.com
Fixes: 63b85ac56a64 ("kasan: stop leaking stack trace handles")
Signed-off-by: Benjamin Gray <bgray@linux.ibm.com>
Reviewed-by: Andrey Konovalov <andreyknvl@gmail.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Vincenzo Frascino <vincenzo.frascino@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
For online parameters change, DAMON_LRU_SORT creates new schemes based on
latest values of the parameters and replaces the old schemes with the new
one. When creating it, the internal status of the quotas of the old
schemes is not preserved. As a result, charging of the quota starts from
zero after the online tuning. The data that collected to estimate the
throughput of the scheme's action is also reset, and therefore the
estimation should start from the scratch again. Because the throughput
estimation is being used to convert the time quota to the effective size
quota, this could result in temporal time quota inaccuracy. It would be
recovered over time, though. In short, the quota accuracy could be
temporarily degraded after online parameters update.
Fix the problem by checking the case and copying the internal fields for
the status.
Link: https://lkml.kernel.org/r/20240216194025.9207-3-sj@kernel.org
Fixes: 40e983cca927 ("mm/damon: introduce DAMON-based LRU-lists Sorting")
Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: <stable@vger.kernel.org> [6.0+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
Patch series "mm/damon: fix quota status loss due to online tunings".
DAMON_RECLAIM and DAMON_LRU_SORT is not preserving internal quota status
when applying new user parameters, and hence could cause temporal quota
accuracy degradation. Fix it by preserving the status.
This patch (of 2):
For online parameters change, DAMON_RECLAIM creates new scheme based on
latest values of the parameters and replaces the old scheme with the new
one. When creating it, the internal status of the quota of the old
scheme is not preserved. As a result, charging of the quota starts from
zero after the online tuning. The data that collected to estimate the
throughput of the scheme's action is also reset, and therefore the
estimation should start from the scratch again. Because the throughput
estimation is being used to convert the time quota to the effective size
quota, this could result in temporal time quota inaccuracy. It would be
recovered over time, though. In short, the quota accuracy could be
temporarily degraded after online parameters update.
Fix the problem by checking the case and copying the internal fields for
the status.
Link: https://lkml.kernel.org/r/20240216194025.9207-1-sj@kernel.org
Link: https://lkml.kernel.org/r/20240216194025.9207-2-sj@kernel.org
Fixes: e035c280f6df ("mm/damon/reclaim: support online inputs update")
Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: <stable@vger.kernel.org> [5.19+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
commit_schemes_quota_goals
'commit_schemes_quota_goals' command handler,
damos_sysfs_set_quota_scores() assumes the number of schemes sysfs
directory will be same to the number of schemes of the DAMON context. The
assumption is wrong since users can remove schemes sysfs directories while
DAMON is running. In the case, illegal memory accesses can happen. Fix
it by checking the case.
Link: https://lkml.kernel.org/r/20240213023633.124928-1-sj@kernel.org
Fixes: d91beaa505a0 ("mm/damon/sysfs-schemes: implement a command for scheme quota goals only commit")
Signed-off-by: SeongJae Park <sj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
The swapaccount deprecation warning is throwing false positives. Since we
deprecated the knob and defaulted to enabling, the only reports we've been
getting are from folks that set swapaccount=1. While this is a nice
affirmation that always-enabling was the right choice, we certainly don't
want to warn when users request the supported mode.
Only warn when disabling is requested, and clarify the warning.
[colin.i.king@gmail.com: spelling: "commdandline" -> "commandline"]
Link: https://lkml.kernel.org/r/20240215090544.1649201-1-colin.i.king@gmail.com
Link: https://lkml.kernel.org/r/20240213081634.3652326-1-hannes@cmpxchg.org
Fixes: b25806dcd3d5 ("mm: memcontrol: deprecate swapaccounting=0 mode")
Signed-off-by: Colin Ian King <colin.i.king@gmail.com>
Reported-by: "Jonas Schäfer" <jonas@wielicki.name>
Reported-by: Narcis Garcia <debianlists@actiu.net>
Suggested-by: Yosry Ahmed <yosryahmed@google.com>
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Reviewed-by: Yosry Ahmed <yosryahmed@google.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Shakeel Butt <shakeelb@google.com>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
The commit 77e6c43e137c ("memblock: introduce MEMBLOCK_RSRV_NOINIT flag")
skipped adding this newly introduced memblock flag into flagname[] array,
thus preventing a correct memblock flags output for applicable memblock
regions.
Link: https://lkml.kernel.org/r/20240209030912.1382251-1-anshuman.khandual@arm.com
Fixes: 77e6c43e137c ("memblock: introduce MEMBLOCK_RSRV_NOINIT flag")
Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
Reviewed-by: Mike Rapoport <rppt@kernel.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
We have to invalidate any duplicate entry even when !zswap_enabled since
zswap can be disabled anytime. If the folio store success before, then
got dirtied again but zswap disabled, we won't invalidate the old
duplicate entry in the zswap_store(). So later lru writeback may
overwrite the new data in swapfile.
Link: https://lkml.kernel.org/r/20240208023254.3873823-1-chengming.zhou@linux.dev
Fixes: 42c06a0e8ebe ("mm: kill frontswap")
Signed-off-by: Chengming Zhou <zhouchengming@bytedance.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Nhat Pham <nphamcs@gmail.com>
Cc: Yosry Ahmed <yosryahmed@google.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
When skipping swapcache for SWP_SYNCHRONOUS_IO, if two or more threads
swapin the same entry at the same time, they get different pages (A, B).
Before one thread (T0) finishes the swapin and installs page (A) to the
PTE, another thread (T1) could finish swapin of page (B), swap_free the
entry, then swap out the possibly modified page reusing the same entry.
It breaks the pte_same check in (T0) because PTE value is unchanged,
causing ABA problem. Thread (T0) will install a stalled page (A) into the
PTE and cause data corruption.
One possible callstack is like this:
CPU0 CPU1
---- ----
do_swap_page() do_swap_page() with same entry
<direct swapin path> <direct swapin path>
<alloc page A> <alloc page B>
swap_read_folio() <- read to page A swap_read_folio() <- read to page B
<slow on later locks or interrupt> <finished swapin first>
... set_pte_at()
swap_free() <- entry is free
<write to page B, now page A stalled>
<swap out page B to same swap entry>
pte_same() <- Check pass, PTE seems
unchanged, but page A
is stalled!
swap_free() <- page B content lost!
set_pte_at() <- staled page A installed!
And besides, for ZRAM, swap_free() allows the swap device to discard the
entry content, so even if page (B) is not modified, if swap_read_folio()
on CPU0 happens later than swap_free() on CPU1, it may also cause data
loss.
To fix this, reuse swapcache_prepare which will pin the swap entry using
the cache flag, and allow only one thread to swap it in, also prevent any
parallel code from putting the entry in the cache. Release the pin after
PT unlocked.
Racers just loop and wait since it's a rare and very short event. A
schedule_timeout_uninterruptible(1) call is added to avoid repeated page
faults wasting too much CPU, causing livelock or adding too much noise to
perf statistics. A similar livelock issue was described in commit
029c4628b2eb ("mm: swap: get rid of livelock in swapin readahead")
Reproducer:
This race issue can be triggered easily using a well constructed
reproducer and patched brd (with a delay in read path) [1]:
With latest 6.8 mainline, race caused data loss can be observed easily:
$ gcc -g -lpthread test-thread-swap-race.c && ./a.out
Polulating 32MB of memory region...
Keep swapping out...
Starting round 0...
Spawning 65536 workers...
32746 workers spawned, wait for done...
Round 0: Error on 0x5aa00, expected 32746, got 32743, 3 data loss!
Round 0: Error on 0x395200, expected 32746, got 32743, 3 data loss!
Round 0: Error on 0x3fd000, expected 32746, got 32737, 9 data loss!
Round 0 Failed, 15 data loss!
This reproducer spawns multiple threads sharing the same memory region
using a small swap device. Every two threads updates mapped pages one by
one in opposite direction trying to create a race, with one dedicated
thread keep swapping out the data out using madvise.
The reproducer created a reproduce rate of about once every 5 minutes, so
the race should be totally possible in production.
After this patch, I ran the reproducer for over a few hundred rounds and
no data loss observed.
Performance overhead is minimal, microbenchmark swapin 10G from 32G
zram:
Before: 10934698 us
After: 11157121 us
Cached: 13155355 us (Dropping SWP_SYNCHRONOUS_IO flag)
[kasong@tencent.com: v4]
Link: https://lkml.kernel.org/r/20240219082040.7495-1-ryncsn@gmail.com
Link: https://lkml.kernel.org/r/20240206182559.32264-1-ryncsn@gmail.com
Fixes: 0bcac06f27d7 ("mm, swap: skip swapcache for swapin of synchronous device")
Reported-by: "Huang, Ying" <ying.huang@intel.com>
Closes: https://lore.kernel.org/lkml/87bk92gqpx.fsf_-_@yhuang6-desk2.ccr.corp.intel.com/
Link: https://github.com/ryncsn/emm-test-project/tree/master/swap-stress-race [1]
Signed-off-by: Kairui Song <kasong@tencent.com>
Reviewed-by: "Huang, Ying" <ying.huang@intel.com>
Acked-by: Yu Zhao <yuzhao@google.com>
Acked-by: David Hildenbrand <david@redhat.com>
Acked-by: Chris Li <chrisl@kernel.org>
Cc: Hugh Dickins <hughd@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Yosry Ahmed <yosryahmed@google.com>
Cc: Yu Zhao <yuzhao@google.com>
Cc: Barry Song <21cnbao@gmail.com>
Cc: SeongJae Park <sj@kernel.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
When a folio is swapped in, the protection size of the corresponding zswap
LRU is incremented, so that the zswap shrinker is more conservative with
its reclaiming action. This field is embedded within the struct lruvec,
so updating it requires looking up the folio's memcg and lruvec. However,
currently this lookup can happen after the folio is unlocked, for instance
if a new folio is allocated, and swap_read_folio() unlocks the folio
before returning. In this scenario, there is no stability guarantee for
the binding between a folio and its memcg and lruvec:
* A folio's memcg and lruvec can be freed between the lookup and the
update, leading to a UAF.
* Folio migration can clear the now-unlocked folio's memcg_data, which
directs the zswap LRU protection size update towards the root memcg
instead of the original memcg. This was recently picked up by the
syzbot thanks to a warning in the inlined folio_lruvec() call.
Move the zswap LRU protection range update above the swap_read_folio()
call, and only when a new page is allocated, to prevent this.
[nphamcs@gmail.com: add VM_WARN_ON_ONCE() to zswap_folio_swapin()]
Link: https://lkml.kernel.org/r/20240206180855.3987204-1-nphamcs@gmail.com
[nphamcs@gmail.com: remove unneeded if (folio) checks]
Link: https://lkml.kernel.org/r/20240206191355.83755-1-nphamcs@gmail.com
Link: https://lkml.kernel.org/r/20240205232442.3240571-1-nphamcs@gmail.com
Fixes: b5ba474f3f51 ("zswap: shrink zswap pool based on memory pressure")
Reported-by: syzbot+17a611d10af7d18a7092@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/all/000000000000ae47f90610803260@google.com/
Signed-off-by: Nhat Pham <nphamcs@gmail.com>
Reviewed-by: Chengming Zhou <zhouchengming@bytedance.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Yosry Ahmed <yosryahmed@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
kdamond_apply_schemes() checks apply intervals of schemes and avoid
further applying any schemes if no scheme passed its apply interval.
However, the following schemes applying function, damon_do_apply_schemes()
iterates all schemes without the apply interval check. As a result, the
shortest apply interval is applied to all schemes. Fix the problem by
checking the apply interval in damon_do_apply_schemes().
Link: https://lkml.kernel.org/r/20240205201306.88562-1-sj@kernel.org
Fixes: 42f994b71404 ("mm/damon/core: implement scheme-specific apply interval")
Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: <stable@vger.kernel.org> [6.7.x]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
In zswap_writeback_entry(), after we get a folio from
__read_swap_cache_async(), we grab the tree lock again to check that the
swap entry was not invalidated and recycled. If it was, we delete the
folio we just added to the swap cache and exit.
However, __read_swap_cache_async() returns the folio locked when it is
newly allocated, which is always true for this path, and the folio is
ref'd. Make sure to unlock and put the folio before returning.
This was discovered by code inspection, probably because this path handles
a race condition that should not happen often, and the bug would not crash
the system, it will only strand the folio indefinitely.
Link: https://lkml.kernel.org/r/20240125085127.1327013-1-yosryahmed@google.com
Fixes: 04fc7816089c ("mm: fix zswap writeback race condition")
Signed-off-by: Yosry Ahmed <yosryahmed@google.com>
Reviewed-by: Chengming Zhou <zhouchengming@bytedance.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Reviewed-by: Nhat Pham <nphamcs@gmail.com>
Cc: Domenico Cerasuolo <cerasuolodomenico@gmail.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
numa_fill_memblks() fills in the gaps in numa_meminfo memblks over a
physical address range. To do so, it first creates a list of existing
memblks that overlap that address range. The issue is that it is off
by one when comparing to the end of the address range, so memblks
that do not overlap are selected.
The impact of selecting a memblk that does not actually overlap is
that an existing memblk may be filled when the expected action is to
do nothing and return NUMA_NO_MEMBLK to the caller. The caller can
then add a new NUMA node and memblk.
Replace the broken open-coded search for address overlap with the
memblock helper memblock_addrs_overlap(). Update the kernel doc
and in code comments.
Suggested by: "Huang, Ying" <ying.huang@intel.com>
Fixes: 8f012db27c95 ("x86/numa: Introduce numa_fill_memblks()")
Signed-off-by: Alison Schofield <alison.schofield@intel.com>
Acked-by: Mike Rapoport (IBM) <rppt@kernel.org>
Acked-by: Dave Hansen <dave.hansen@linux.intel.com>
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Link: https://lore.kernel.org/r/10a3e6109c34c21a8dd4c513cf63df63481a2b07.1705085543.git.alison.schofield@intel.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
|
|
On architectures with delay slot, instruction_pointer() may differ
from where exception was triggered.
Use exception_ip we just introduced to search exception tables to
get rid of the problem.
Fixes: 4bce37a68ff8 ("mips/mm: Convert to using lock_mm_and_find_vma()")
Reported-by: Xi Ruoyao <xry111@xry111.site>
Link: https://lore.kernel.org/r/75e9fd7b08562ad9b456a5bdaacb7cc220311cc9.camel@xry111.site/
Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Jiaxun Yang <jiaxun.yang@flygoat.com>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Pull misc fixes from Andrew Morton:
"21 hotfixes. 12 are cc:stable and the remainder pertain to post-6.7
issues or aren't considered to be needed in earlier kernel versions"
* tag 'mm-hotfixes-stable-2024-02-10-11-16' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (21 commits)
nilfs2: fix potential bug in end_buffer_async_write
mm/damon/sysfs-schemes: fix wrong DAMOS tried regions update timeout setup
nilfs2: fix hang in nilfs_lookup_dirty_data_buffers()
MAINTAINERS: Leo Yan has moved
mm/zswap: don't return LRU_SKIP if we have dropped lru lock
fs,hugetlb: fix NULL pointer dereference in hugetlbs_fill_super
mailmap: switch email address for John Moon
mm: zswap: fix objcg use-after-free in entry destruction
mm/madvise: don't forget to leave lazy MMU mode in madvise_cold_or_pageout_pte_range()
arch/arm/mm: fix major fault accounting when retrying under per-VMA lock
selftests: core: include linux/close_range.h for CLOSE_RANGE_* macros
mm/memory-failure: fix crash in split_huge_page_to_list from soft_offline_page
mm: memcg: optimize parent iteration in memcg_rstat_updated()
nilfs2: fix data corruption in dsync block recovery for small block sizes
mm/userfaultfd: UFFDIO_MOVE implementation should use ptep_get()
exit: wait_task_zombie: kill the no longer necessary spin_lock_irq(siglock)
fs/proc: do_task_stat: use sig->stats_lock to gather the threads/children stats
fs/proc: do_task_stat: move thread_group_cputime_adjusted() outside of lock_task_sighand()
getrusage: use sig->stats_lock rather than lock_task_sighand()
getrusage: move thread_group_cputime_adjusted() outside of lock_task_sighand()
...
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Pull block fixes from Jens Axboe:
- NVMe pull request via Keith:
- Update a potentially stale firmware attribute (Maurizio)
- Fixes for the recent verbose error logging (Keith, Chaitanya)
- Protection information payload size fix for passthrough (Francis)
- Fix for a queue freezing issue in virtblk (Yi)
- blk-iocost underflow fix (Tejun)
- blk-wbt task detection fix (Jan)
* tag 'block-6.8-2024-02-10' of git://git.kernel.dk/linux:
virtio-blk: Ensure no requests in virtqueues before deleting vqs.
blk-iocost: Fix an UBSAN shift-out-of-bounds warning
nvme: use ns->head->pi_size instead of t10_pi_tuple structure size
nvme-core: fix comment to reflect right functions
nvme: move passthrough logging attribute to head
blk-wbt: Fix detection of dirty-throttled tasks
nvme-host: fix the updating of the firmware version
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DAMON sysfs interface's update_schemes_tried_regions command has a timeout
of two apply intervals of the DAMOS scheme. Having zero value DAMOS
scheme apply interval means it will use the aggregation interval as the
value. However, the timeout setup logic is mistakenly using the sampling
interval insted of the aggregartion interval for the case. This could
cause earlier-than-expected timeout of the command. Fix it.
Link: https://lkml.kernel.org/r/20240202191956.88791-1-sj@kernel.org
Fixes: 7d6fa31a2fd7 ("mm/damon/sysfs-schemes: add timeout for update_schemes_tried_regions")
Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: <stable@vger.kernel.org> # 6.7.x
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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LRU_SKIP can only be returned if we don't ever dropped lru lock, or we
need to return LRU_RETRY to restart from the head of lru list.
Otherwise, the iteration might continue from a cursor position that was
freed while the locks were dropped.
Actually we may need to introduce another LRU_STOP to really terminate the
ongoing shrinking scan process, when we encounter a warm page already in
the swap cache. The current list_lru implementation doesn't have this
function to early break from __list_lru_walk_one.
Link: https://lkml.kernel.org/r/20240126-zswap-writeback-race-v2-1-b10479847099@bytedance.com
Fixes: b5ba474f3f51 ("zswap: shrink zswap pool based on memory pressure")
Signed-off-by: Chengming Zhou <zhouchengming@bytedance.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Reviewed-by: Nhat Pham <nphamcs@gmail.com>
Cc: Chris Li <chriscli@google.com>
Cc: Yosry Ahmed <yosryahmed@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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In the per-memcg LRU universe, LRU removal uses entry->objcg to determine
which list count needs to be decreased. Drop the objcg reference after
updating the LRU, to fix a possible use-after-free.
Link: https://lkml.kernel.org/r/20240130013438.565167-1-hannes@cmpxchg.org
Fixes: a65b0e7607cc ("zswap: make shrinking memcg-aware")
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Yosry Ahmed <yosryahmed@google.com>
Reviewed-by: Nhat Pham <nphamcs@gmail.com>
Reviewed-by: Chengming Zhou <zhouchengming@bytedance.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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madvise_cold_or_pageout_pte_range()
We need to leave lazy MMU mode before unlocking.
Link: https://lkml.kernel.org/r/20240126032608.355899-1-senozhatsky@chromium.org
Fixes: b2f557a21bc8 ("mm/madvise: add cond_resched() in madvise_cold_or_pageout_pte_range()")
Signed-off-by: Sergey Senozhatsky <senozhatsky@chromium.org>
Cc: Jiexun Wang <wangjiexun@tinylab.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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When I did soft offline stress test, a machine was observed to crash with
the following message:
kernel BUG at include/linux/memcontrol.h:554!
invalid opcode: 0000 [#1] PREEMPT SMP NOPTI
CPU: 5 PID: 3837 Comm: hwpoison.sh Not tainted 6.7.0-next-20240112-00001-g8ecf3e7fb7c8-dirty #97
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.14.0-0-g155821a1990b-prebuilt.qemu.org 04/01/2014
RIP: 0010:folio_memcg+0xaf/0xd0
Code: 10 5b 5d c3 cc cc cc cc 48 c7 c6 08 b1 f2 b2 48 89 ef e8 b4 c5 f8 ff 90 0f 0b 48 c7 c6 d0 b0 f2 b2 48 89 ef e8 a2 c5 f8 ff 90 <0f> 0b 48 c7 c6 08 b1 f2 b2 48 89 ef e8 90 c5 f8 ff 90 0f 0b 66 66
RSP: 0018:ffffb6c043657c98 EFLAGS: 00000296
RAX: 000000000000004b RBX: ffff932bc1d1e401 RCX: ffff933abfb5c908
RDX: 0000000000000000 RSI: 0000000000000027 RDI: ffff933abfb5c900
RBP: ffffea6f04019080 R08: ffffffffb3338ce8 R09: 0000000000009ffb
R10: 00000000000004dd R11: ffffffffb3308d00 R12: ffffea6f04019080
R13: ffffea6f04019080 R14: 0000000000000001 R15: ffffb6c043657da0
FS: 00007f6c60f6b740(0000) GS:ffff933abfb40000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000559c3bc8b980 CR3: 0000000107f1c000 CR4: 00000000000006f0
Call Trace:
<TASK>
split_huge_page_to_list+0x4d/0x1380
try_to_split_thp_page+0x3a/0xf0
soft_offline_page+0x1ea/0x8a0
soft_offline_page_store+0x52/0x90
kernfs_fop_write_iter+0x118/0x1b0
vfs_write+0x30b/0x430
ksys_write+0x5e/0xe0
do_syscall_64+0xb0/0x1b0
entry_SYSCALL_64_after_hwframe+0x6d/0x75
RIP: 0033:0x7f6c60d14697
Code: 10 00 f7 d8 64 89 02 48 c7 c0 ff ff ff ff eb b7 0f 1f 00 f3 0f 1e fa 64 8b 04 25 18 00 00 00 85 c0 75 10 b8 01 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 51 c3 48 83 ec 28 48 89 54 24 18 48 89 74 24
RSP: 002b:00007ffe9b72b8d8 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 000000000000000c RCX: 00007f6c60d14697
RDX: 000000000000000c RSI: 0000559c3bc8b980 RDI: 0000000000000001
RBP: 0000559c3bc8b980 R08: 00007f6c60dd1460 R09: 000000007fffffff
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000000000c
R13: 00007f6c60e1a780 R14: 00007f6c60e16600 R15: 00007f6c60e15a00
The problem is that page->mapping is overloaded with slab->slab_list or
slabs fields now, so slab pages could be taken as non-LRU movable pages if
field slabs contains PAGE_MAPPING_MOVABLE or slab_list->prev is set to
LIST_POISON2. These slab pages will be treated as thp later leading to
crash in split_huge_page_to_list().
Link: https://lkml.kernel.org/r/20240126065837.2100184-1-linmiaohe@huawei.com
Link: https://lkml.kernel.org/r/20240124084014.1772906-1-linmiaohe@huawei.com
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Fixes: 130d4df57390 ("mm/sl[au]b: rearrange struct slab fields to allow larger rcu_head")
Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Naoya Horiguchi <naoya.horiguchi@nec.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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In memcg_rstat_updated(), we iterate the memcg being updated and its
parents to update memcg->vmstats_percpu->stats_updates in the fast path
(i.e. no atomic updates). According to my math, this is 3 memory loads
(and potentially 3 cache misses) per memcg:
- Load the address of memcg->vmstats_percpu.
- Load vmstats_percpu->stats_updates (based on some percpu calculation).
- Load the address of the parent memcg.
Avoid most of the cache misses by caching a pointer from each struct
memcg_vmstats_percpu to its parent on the corresponding CPU. In this
case, for the first memcg we have 2 memory loads (same as above):
- Load the address of memcg->vmstats_percpu.
- Load vmstats_percpu->stats_updates (based on some percpu calculation).
Then for each additional memcg, we need a single load to get the
parent's stats_updates directly. This reduces the number of loads from
O(3N) to O(2+N) -- where N is the number of memcgs we need to iterate.
Additionally, stash a pointer to memcg->vmstats in each struct
memcg_vmstats_percpu such that we can access the atomic counter that all
CPUs fold into, memcg->vmstats->stats_updates.
memcg_should_flush_stats() is changed to memcg_vmstats_needs_flush() to
accept a struct memcg_vmstats pointer accordingly.
In struct memcg_vmstats_percpu, make sure both pointers together with
stats_updates live on the same cacheline. Finally, update
mem_cgroup_alloc() to take in a parent pointer and initialize the new
cache pointers on each CPU. The percpu loop in mem_cgroup_alloc() may
look concerning, but there are multiple similar loops in the cgroup
creation path (e.g. cgroup_rstat_init()), most of which are hidden
within alloc_percpu().
According to Oliver's testing [1], this fixes multiple 30-38%
regressions in vm-scalability, will-it-scale-tlb_flush2, and
will-it-scale-fallocate1. This comes at a cost of 2 more pointers per
CPU (<2KB on a machine with 128 CPUs).
[1] https://lore.kernel.org/lkml/ZbDJsfsZt2ITyo61@xsang-OptiPlex-9020/
[yosryahmed@google.com: fix struct memcg_vmstats_percpu size and alignment]
Link: https://lkml.kernel.org/r/20240203044612.1234216-1-yosryahmed@google.com
Link: https://lkml.kernel.org/r/20240124100023.660032-1-yosryahmed@google.com
Signed-off-by: Yosry Ahmed <yosryahmed@google.com>
Fixes: 8d59d2214c23 ("mm: memcg: make stats flushing threshold per-memcg")
Tested-by: kernel test robot <oliver.sang@intel.com>
Reported-by: kernel test robot <oliver.sang@intel.com>
Closes: https://lore.kernel.org/oe-lkp/202401221624.cb53a8ca-oliver.sang@intel.com
Acked-by: Shakeel Butt <shakeelb@google.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Greg Thelen <gthelen@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Commit c33c794828f2 ("mm: ptep_get() conversion") converted all (non-arch)
call sites to use ptep_get() instead of doing a direct dereference of the
pte. Full rationale can be found in that commit's log.
Since then, UFFDIO_MOVE has been implemented which does 7 direct pte
dereferences. Let's fix those up to use ptep_get().
I've asserted in the past that there is no reliable automated mechanism to
catch these; I'm relying on a combination of Coccinelle (which throws up a
lot of false positives) and some compiler magic to force a compiler error
on dereference. But given the frequency with which new issues are coming
up, I'll add it to my todo list to try to find an automated solution.
Link: https://lkml.kernel.org/r/20240123141755.3836179-1-ryan.roberts@arm.com
Fixes: adef440691ba ("userfaultfd: UFFDIO_MOVE uABI")
Signed-off-by: Ryan Roberts <ryan.roberts@arm.com>
Reviewed-by: Suren Baghdasaryan <surenb@google.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: David Hildenbrand <david@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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The detection of dirty-throttled tasks in blk-wbt has been subtly broken
since its beginning in 2016. Namely if we are doing cgroup writeback and
the throttled task is not in the root cgroup, balance_dirty_pages() will
set dirty_sleep for the non-root bdi_writeback structure. However
blk-wbt checks dirty_sleep only in the root cgroup bdi_writeback
structure. Thus detection of recently throttled tasks is not working in
this case (we noticed this when we switched to cgroup v2 and suddently
writeback was slow).
Since blk-wbt has no easy way to get to proper bdi_writeback and
furthermore its intention has always been to work on the whole device
rather than on individual cgroups, just move the dirty_sleep timestamp
from bdi_writeback to backing_dev_info. That fixes the checking for
recently throttled task and saves memory for everybody as a bonus.
CC: stable@vger.kernel.org
Fixes: b57d74aff9ab ("writeback: track if we're sleeping on progress in balance_dirty_pages()")
Signed-off-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20240123175826.21452-1-jack@suse.cz
[axboe: fixup indentation errors]
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Pull misc fixes from Andrew Morton:
"22 hotfixes. 11 are cc:stable and the remainder address post-6.7
issues or aren't considered appropriate for backporting"
* tag 'mm-hotfixes-stable-2024-01-28-23-21' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (22 commits)
mm: thp_get_unmapped_area must honour topdown preference
mm: huge_memory: don't force huge page alignment on 32 bit
userfaultfd: fix mmap_changing checking in mfill_atomic_hugetlb
selftests/mm: ksm_tests should only MADV_HUGEPAGE valid memory
scs: add CONFIG_MMU dependency for vfree_atomic()
mm/memory: fix folio_set_dirty() vs. folio_mark_dirty() in zap_pte_range()
mm/huge_memory: fix folio_set_dirty() vs. folio_mark_dirty()
selftests/mm: Update va_high_addr_switch.sh to check CPU for la57 flag
selftests: mm: fix map_hugetlb failure on 64K page size systems
MAINTAINERS: supplement of zswap maintainers update
stackdepot: make fast paths lock-less again
stackdepot: add stats counters exported via debugfs
mm, kmsan: fix infinite recursion due to RCU critical section
mm/writeback: fix possible divide-by-zero in wb_dirty_limits(), again
selftests/mm: switch to bash from sh
MAINTAINERS: add man-pages git trees
mm: memcontrol: don't throttle dying tasks on memory.high
mm: mmap: map MAP_STACK to VM_NOHUGEPAGE
uprobes: use pagesize-aligned virtual address when replacing pages
selftests/mm: mremap_test: fix build warning
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