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18014 Commits
| Author | SHA1 | Message | Date | |
|---|---|---|---|---|
 Zqiang
|
31fa985b41 |
kasan: prevent cpu_quarantine corruption when CPU offline and cache shrink occur at same time
kasan_quarantine_remove_cache() is called in kmem_cache_shrink()/ destroy(). The kasan_quarantine_remove_cache() call is protected by cpuslock in kmem_cache_destroy() to ensure serialization with kasan_cpu_offline(). However the kasan_quarantine_remove_cache() call is not protected by cpuslock in kmem_cache_shrink(). When a CPU is going offline and cache shrink occurs at same time, the cpu_quarantine may be corrupted by interrupt (per_cpu_remove_cache operation). So add a cpu_quarantine offline flags check in per_cpu_remove_cache(). [akpm@linux-foundation.org: add comment, per Zqiang] Link: https://lkml.kernel.org/r/20220414025925.2423818-1-qiang1.zhang@intel.com Signed-off-by: Zqiang <qiang1.zhang@intel.com> Reviewed-by: Dmitry Vyukov <dvyukov@google.com> Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com> Cc: Alexander Potapenko <glider@google.com> Cc: Andrey Konovalov <andreyknvl@gmail.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
||
 Linus Torvalds
|
0fc74d820a |
no-MMU: expose vmalloc_huge() for alloc_large_system_hash()
It turns out that for the CONFIG_MMU=n builds, vmalloc_huge() was never defined, since it's defined in mm/vmalloc.c, which doesn't get built for the no-MMU configurations. Just implement the trivial wrapper for the no-MMU case too. In fact, just make it an alias to the existing __vmalloc() function that has the same signature. Link: https://lore.kernel.org/all/CAMuHMdVdx2V1uhv_152Sw3_z2xE0spiaWp1d6Ko8-rYmAxUBAg@mail.gmail.com/ Link: https://lore.kernel.org/all/CA+G9fYscb1y4a17Sf5G_Aibt+WuSf-ks_Qjw9tYFy=A4sjCEug@mail.gmail.com/ Link: https://lore.kernel.org/all/20220425150356.GA4138752@roeck-us.net/ Reported-and-tested-by: Linux Kernel Functional Testing <lkft@linaro.org> Reported-and-tested-by: Geert Uytterhoeven <geert@linux-m68k.org> Reported-by: Sudip Mukherjee <sudipm.mukherjee@gmail.com> Reported-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
||
|
Linus Torvalds
|
9becb68891 |
kvmalloc: use vmalloc_huge for vmalloc allocations
Since commit |
||
 Song Liu
|
f2edd118d0 |
page_alloc: use vmalloc_huge for large system hash
Use vmalloc_huge() in alloc_large_system_hash() so that large system hash (>= PMD_SIZE) could benefit from huge pages. Note that vmalloc_huge only allocates huge pages for systems with HAVE_ARCH_HUGE_VMALLOC. Signed-off-by: Song Liu <song@kernel.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Rik van Riel <riel@surriel.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
||
|
Linus Torvalds
|
281b9d9a4b |
Merge branch 'akpm' (patches from Andrew)
Merge misc fixes from Andrew Morton: "13 patches. Subsystems affected by this patch series: mm (memory-failure, memcg, userfaultfd, hugetlbfs, mremap, oom-kill, kasan, hmm), and kcov" * emailed patches from Andrew Morton <akpm@linux-foundation.org>: mm/mmu_notifier.c: fix race in mmu_interval_notifier_remove() kcov: don't generate a warning on vm_insert_page()'s failure MAINTAINERS: add Vincenzo Frascino to KASAN reviewers oom_kill.c: futex: delay the OOM reaper to allow time for proper futex cleanup selftest/vm: add skip support to mremap_test selftest/vm: support xfail in mremap_test selftest/vm: verify remap destination address in mremap_test selftest/vm: verify mmap addr in mremap_test mm, hugetlb: allow for "high" userspace addresses userfaultfd: mark uffd_wp regardless of VM_WRITE flag memcg: sync flush only if periodic flush is delayed mm/memory-failure.c: skip huge_zero_page in memory_failure() mm/hwpoison: fix race between hugetlb free/demotion and memory_failure_hugetlb() |
||
 Nicholas Piggin
|
3b8000ae18 |
mm/vmalloc: huge vmalloc backing pages should be split rather than compound
Huge vmalloc higher-order backing pages were allocated with __GFP_COMP in order to allow the sub-pages to be refcounted by callers such as "remap_vmalloc_page [sic]" (remap_vmalloc_range). However a similar problem exists for other struct page fields callers use, for example fb_deferred_io_fault() takes a vmalloc'ed page and not only refcounts it but uses ->lru, ->mapping, ->index. This is not compatible with compound sub-pages, and can cause bad page state issues like BUG: Bad page state in process swapper/0 pfn:00743 page:(____ptrval____) refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x743 flags: 0x7ffff000000000(node=0|zone=0|lastcpupid=0x7ffff) raw: 007ffff000000000 c00c00000001d0c8 c00c00000001d0c8 0000000000000000 raw: 0000000000000000 0000000000000000 00000000ffffffff 0000000000000000 page dumped because: corrupted mapping in tail page Modules linked in: CPU: 0 PID: 1 Comm: swapper/0 Not tainted 5.18.0-rc3-00082-gfc6fff4a7ce1-dirty #2810 Call Trace: dump_stack_lvl+0x74/0xa8 (unreliable) bad_page+0x12c/0x170 free_tail_pages_check+0xe8/0x190 free_pcp_prepare+0x31c/0x4e0 free_unref_page+0x40/0x1b0 __vunmap+0x1d8/0x420 ... The correct approach is to use split high-order pages for the huge vmalloc backing. These allow callers to treat them in exactly the same way as individually-allocated order-0 pages. Link: https://lore.kernel.org/all/14444103-d51b-0fb3-ee63-c3f182f0b546@molgen.mpg.de/ Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Cc: Paul Menzel <pmenzel@molgen.mpg.de> Cc: Song Liu <songliubraving@fb.com> Cc: Rick Edgecombe <rick.p.edgecombe@intel.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
||
 Alistair Popple
|
319561669a |
mm/mmu_notifier.c: fix race in mmu_interval_notifier_remove()
In some cases it is possible for mmu_interval_notifier_remove() to race
with mn_tree_inv_end() allowing it to return while the notifier data
structure is still in use. Consider the following sequence:
CPU0 - mn_tree_inv_end() CPU1 - mmu_interval_notifier_remove()
----------------------------------- ------------------------------------
spin_lock(subscriptions->lock);
seq = subscriptions->invalidate_seq;
spin_lock(subscriptions->lock); spin_unlock(subscriptions->lock);
subscriptions->invalidate_seq++;
wait_event(invalidate_seq != seq);
return;
interval_tree_remove(interval_sub); kfree(interval_sub);
spin_unlock(subscriptions->lock);
wake_up_all();
As the wait_event() condition is true it will return immediately. This
can lead to use-after-free type errors if the caller frees the data
structure containing the interval notifier subscription while it is
still on a deferred list. Fix this by taking the appropriate lock when
reading invalidate_seq to ensure proper synchronisation.
I observed this whilst running stress testing during some development.
You do have to be pretty unlucky, but it leads to the usual problems of
use-after-free (memory corruption, kernel crash, difficult to diagnose
WARN_ON, etc).
Link: https://lkml.kernel.org/r/20220420043734.476348-1-apopple@nvidia.com
Fixes:
|
||
 Nico Pache
|
e4a38402c3 |
oom_kill.c: futex: delay the OOM reaper to allow time for proper futex cleanup
The pthread struct is allocated on PRIVATE|ANONYMOUS memory [1] which
can be targeted by the oom reaper. This mapping is used to store the
futex robust list head; the kernel does not keep a copy of the robust
list and instead references a userspace address to maintain the
robustness during a process death.
A race can occur between exit_mm and the oom reaper that allows the oom
reaper to free the memory of the futex robust list before the exit path
has handled the futex death:
CPU1 CPU2
--------------------------------------------------------------------
page_fault
do_exit "signal"
wake_oom_reaper
oom_reaper
oom_reap_task_mm (invalidates mm)
exit_mm
exit_mm_release
futex_exit_release
futex_cleanup
exit_robust_list
get_user (EFAULT- can't access memory)
If the get_user EFAULT's, the kernel will be unable to recover the
waiters on the robust_list, leaving userspace mutexes hung indefinitely.
Delay the OOM reaper, allowing more time for the exit path to perform
the futex cleanup.
Reproducer: https://gitlab.com/jsavitz/oom_futex_reproducer
Based on a patch by Michal Hocko.
Link: https://elixir.bootlin.com/glibc/glibc-2.35/source/nptl/allocatestack.c#L370 [1]
Link: https://lkml.kernel.org/r/20220414144042.677008-1-npache@redhat.com
Fixes:
|
||
 Christophe Leroy
|
5f24d5a579 |
mm, hugetlb: allow for "high" userspace addresses
This is a fix for commit |
||
 Nadav Amit
|
0e88904cb7 |
userfaultfd: mark uffd_wp regardless of VM_WRITE flag
When a PTE is set by UFFD operations such as UFFDIO_COPY, the PTE is
currently only marked as write-protected if the VMA has VM_WRITE flag
set. This seems incorrect or at least would be unexpected by the users.
Consider the following sequence of operations that are being performed
on a certain page:
mprotect(PROT_READ)
UFFDIO_COPY(UFFDIO_COPY_MODE_WP)
mprotect(PROT_READ|PROT_WRITE)
At this point the user would expect to still get UFFD notification when
the page is accessed for write, but the user would not get one, since
the PTE was not marked as UFFD_WP during UFFDIO_COPY.
Fix it by always marking PTEs as UFFD_WP regardless on the
write-permission in the VMA flags.
Link: https://lkml.kernel.org/r/20220217211602.2769-1-namit@vmware.com
Fixes:
|
||
 Shakeel Butt
|
9b3016154c |
memcg: sync flush only if periodic flush is delayed
Daniel Dao has reported [1] a regression on workloads that may trigger a
lot of refaults (anon and file). The underlying issue is that flushing
rstat is expensive. Although rstat flush are batched with (nr_cpus *
MEMCG_BATCH) stat updates, it seems like there are workloads which
genuinely do stat updates larger than batch value within short amount of
time. Since the rstat flush can happen in the performance critical
codepaths like page faults, such workload can suffer greatly.
This patch fixes this regression by making the rstat flushing
conditional in the performance critical codepaths. More specifically,
the kernel relies on the async periodic rstat flusher to flush the stats
and only if the periodic flusher is delayed by more than twice the
amount of its normal time window then the kernel allows rstat flushing
from the performance critical codepaths.
Now the question: what are the side-effects of this change? The worst
that can happen is the refault codepath will see 4sec old lruvec stats
and may cause false (or missed) activations of the refaulted page which
may under-or-overestimate the workingset size. Though that is not very
concerning as the kernel can already miss or do false activations.
There are two more codepaths whose flushing behavior is not changed by
this patch and we may need to come to them in future. One is the
writeback stats used by dirty throttling and second is the deactivation
heuristic in the reclaim. For now keeping an eye on them and if there
is report of regression due to these codepaths, we will reevaluate then.
Link: https://lore.kernel.org/all/CA+wXwBSyO87ZX5PVwdHm-=dBjZYECGmfnydUicUyrQqndgX2MQ@mail.gmail.com [1]
Link: https://lkml.kernel.org/r/20220304184040.1304781-1-shakeelb@google.com
Fixes:
|
||
 Xu Yu
|
d173d5417f |
mm/memory-failure.c: skip huge_zero_page in memory_failure()
Kernel panic when injecting memory_failure for the global
huge_zero_page, when CONFIG_DEBUG_VM is enabled, as follows.
Injecting memory failure for pfn 0x109ff9 at process virtual address 0x20ff9000
page:00000000fb053fc3 refcount:2 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x109e00
head:00000000fb053fc3 order:9 compound_mapcount:0 compound_pincount:0
flags: 0x17fffc000010001(locked|head|node=0|zone=2|lastcpupid=0x1ffff)
raw: 017fffc000010001 0000000000000000 dead000000000122 0000000000000000
raw: 0000000000000000 0000000000000000 00000002ffffffff 0000000000000000
page dumped because: VM_BUG_ON_PAGE(is_huge_zero_page(head))
------------[ cut here ]------------
kernel BUG at mm/huge_memory.c:2499!
invalid opcode: 0000 [#1] PREEMPT SMP PTI
CPU: 6 PID: 553 Comm: split_bug Not tainted 5.18.0-rc1+ #11
Hardware name: Alibaba Cloud Alibaba Cloud ECS, BIOS 3288b3c 04/01/2014
RIP: 0010:split_huge_page_to_list+0x66a/0x880
Code: 84 9b fb ff ff 48 8b 7c 24 08 31 f6 e8 9f 5d 2a 00 b8 b8 02 00 00 e9 e8 fb ff ff 48 c7 c6 e8 47 3c 82 4c b
RSP: 0018:ffffc90000dcbdf8 EFLAGS: 00010246
RAX: 000000000000003c RBX: 0000000000000001 RCX: 0000000000000000
RDX: 0000000000000000 RSI: ffffffff823e4c4f RDI: 00000000ffffffff
RBP: ffff88843fffdb40 R08: 0000000000000000 R09: 00000000fffeffff
R10: ffffc90000dcbc48 R11: ffffffff82d68448 R12: ffffea0004278000
R13: ffffffff823c6203 R14: 0000000000109ff9 R15: ffffea000427fe40
FS: 00007fc375a26740(0000) GS:ffff88842fd80000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fc3757c9290 CR3: 0000000102174006 CR4: 00000000003706e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
try_to_split_thp_page+0x3a/0x130
memory_failure+0x128/0x800
madvise_inject_error.cold+0x8b/0xa1
__x64_sys_madvise+0x54/0x60
do_syscall_64+0x35/0x80
entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x7fc3754f8bf9
Code: 01 00 48 81 c4 80 00 00 00 e9 f1 fe ff ff 0f 1f 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 8
RSP: 002b:00007ffeda93a1d8 EFLAGS: 00000217 ORIG_RAX: 000000000000001c
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fc3754f8bf9
RDX: 0000000000000064 RSI: 0000000000003000 RDI: 0000000020ff9000
RBP: 00007ffeda93a200 R08: 0000000000000000 R09: 0000000000000000
R10: 00000000ffffffff R11: 0000000000000217 R12: 0000000000400490
R13: 00007ffeda93a2e0 R14: 0000000000000000 R15: 0000000000000000
This makes huge_zero_page bail out explicitly before split in
memory_failure(), thus the panic above won't happen again.
Link: https://lkml.kernel.org/r/497d3835612610e370c74e697ea3c721d1d55b9c.1649775850.git.xuyu@linux.alibaba.com
Fixes:
|
||
 Naoya Horiguchi
|
405ce05123 |
mm/hwpoison: fix race between hugetlb free/demotion and memory_failure_hugetlb()
There is a race condition between memory_failure_hugetlb() and hugetlb
free/demotion, which causes setting PageHWPoison flag on the wrong page.
The one simple result is that wrong processes can be killed, but another
(more serious) one is that the actual error is left unhandled, so no one
prevents later access to it, and that might lead to more serious results
like consuming corrupted data.
Think about the below race window:
CPU 1 CPU 2
memory_failure_hugetlb
struct page *head = compound_head(p);
hugetlb page might be freed to
buddy, or even changed to another
compound page.
get_hwpoison_page -- page is not what we want now...
The current code first does prechecks roughly and then reconfirms after
taking refcount, but it's found that it makes code overly complicated,
so move the prechecks in a single hugetlb_lock range.
A newly introduced function, try_memory_failure_hugetlb(), always takes
hugetlb_lock (even for non-hugetlb pages). That can be improved, but
memory_failure() is rare in principle, so should not be a big problem.
Link: https://lkml.kernel.org/r/20220408135323.1559401-2-naoya.horiguchi@linux.dev
Fixes:
|
||
|
Song Liu
|
559089e0a9 |
vmalloc: replace VM_NO_HUGE_VMAP with VM_ALLOW_HUGE_VMAP
Huge page backed vmalloc memory could benefit performance in many cases.
However, some users of vmalloc may not be ready to handle huge pages for
various reasons: hardware constraints, potential pages split, etc.
VM_NO_HUGE_VMAP was introduced to allow vmalloc users to opt-out huge
pages. However, it is not easy to track down all the users that require
the opt-out, as the allocation are passed different stacks and may cause
issues in different layers.
To address this issue, replace VM_NO_HUGE_VMAP with an opt-in flag,
VM_ALLOW_HUGE_VMAP, so that users that benefit from huge pages could ask
specificially.
Also, remove vmalloc_no_huge() and add opt-in helper vmalloc_huge().
Fixes:
|
||
 Patrick Wang
|
23c2d497de |
mm: kmemleak: take a full lowmem check in kmemleak_*_phys()
The kmemleak_*_phys() apis do not check the address for lowmem's min boundary, while the caller may pass an address below lowmem, which will trigger an oops: # echo scan > /sys/kernel/debug/kmemleak Unable to handle kernel paging request at virtual address ff5fffffffe00000 Oops [#1] Modules linked in: CPU: 2 PID: 134 Comm: bash Not tainted 5.18.0-rc1-next-20220407 #33 Hardware name: riscv-virtio,qemu (DT) epc : scan_block+0x74/0x15c ra : scan_block+0x72/0x15c epc : ffffffff801e5806 ra : ffffffff801e5804 sp : ff200000104abc30 gp : ffffffff815cd4e8 tp : ff60000004cfa340 t0 : 0000000000000200 t1 : 00aaaaaac23954cc t2 : 00000000000003ff s0 : ff200000104abc90 s1 : ffffffff81b0ff28 a0 : 0000000000000000 a1 : ff5fffffffe01000 a2 : ffffffff81b0ff28 a3 : 0000000000000002 a4 : 0000000000000001 a5 : 0000000000000000 a6 : ff200000104abd7c a7 : 0000000000000005 s2 : ff5fffffffe00ff9 s3 : ffffffff815cd998 s4 : ffffffff815d0e90 s5 : ffffffff81b0ff28 s6 : 0000000000000020 s7 : ffffffff815d0eb0 s8 : ffffffffffffffff s9 : ff5fffffffe00000 s10: ff5fffffffe01000 s11: 0000000000000022 t3 : 00ffffffaa17db4c t4 : 000000000000000f t5 : 0000000000000001 t6 : 0000000000000000 status: 0000000000000100 badaddr: ff5fffffffe00000 cause: 000000000000000d scan_gray_list+0x12e/0x1a6 kmemleak_scan+0x2aa/0x57e kmemleak_write+0x32a/0x40c full_proxy_write+0x56/0x82 vfs_write+0xa6/0x2a6 ksys_write+0x6c/0xe2 sys_write+0x22/0x2a ret_from_syscall+0x0/0x2 The callers may not quite know the actual address they pass(e.g. from devicetree). So the kmemleak_*_phys() apis should guarantee the address they finally use is in lowmem range, so check the address for lowmem's min boundary. Link: https://lkml.kernel.org/r/20220413122925.33856-1-patrick.wang.shcn@gmail.com Signed-off-by: Patrick Wang <patrick.wang.shcn@gmail.com> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
||
 Omar Sandoval
|
c12cd77cb0 |
mm/vmalloc: fix spinning drain_vmap_work after reading from /proc/vmcore
Commit |
||
 Mike Kravetz
|
5a317412ef |
hugetlb: do not demote poisoned hugetlb pages
It is possible for poisoned hugetlb pages to reside on the free lists.
The huge page allocation routines which dequeue entries from the free
lists make a point of avoiding poisoned pages. There is no such check
and avoidance in the demote code path.
If a hugetlb page on the is on a free list, poison will only be set in
the head page rather then the page with the actual error. If such a
page is demoted, then the poison flag may follow the wrong page. A page
without error could have poison set, and a page with poison could not
have the flag set.
Check for poison before attempting to demote a hugetlb page. Also,
return -EBUSY to the caller if only poisoned pages are on the free list.
Link: https://lkml.kernel.org/r/20220307215707.50916-1-mike.kravetz@oracle.com
Fixes:
|
||
 Charan Teja Kalla
|
31ca72fa75 |
mm: compaction: fix compiler warning when CONFIG_COMPACTION=n
The below warning is reported when CONFIG_COMPACTION=n:
mm/compaction.c:56:27: warning: 'HPAGE_FRAG_CHECK_INTERVAL_MSEC' defined but not used [-Wunused-const-variable=]
56 | static const unsigned int HPAGE_FRAG_CHECK_INTERVAL_MSEC = 500;
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Fix it by moving 'HPAGE_FRAG_CHECK_INTERVAL_MSEC' under
CONFIG_COMPACTION defconfig.
Also since this is just a 'static const int' type, use #define for it.
Link: https://lkml.kernel.org/r/1647608518-20924-1-git-send-email-quic_charante@quicinc.com
Signed-off-by: Charan Teja Kalla <quic_charante@quicinc.com>
Reported-by: kernel test robot <lkp@intel.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Nitin Gupta <nigupta@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
||
 Minchan Kim
|
e914d8f003 |
mm: fix unexpected zeroed page mapping with zram swap
Two processes under CLONE_VM cloning, user process can be corrupted by
seeing zeroed page unexpectedly.
CPU A CPU B
do_swap_page do_swap_page
SWP_SYNCHRONOUS_IO path SWP_SYNCHRONOUS_IO path
swap_readpage valid data
swap_slot_free_notify
delete zram entry
swap_readpage zeroed(invalid) data
pte_lock
map the *zero data* to userspace
pte_unlock
pte_lock
if (!pte_same)
goto out_nomap;
pte_unlock
return and next refault will
read zeroed data
The swap_slot_free_notify is bogus for CLONE_VM case since it doesn't
increase the refcount of swap slot at copy_mm so it couldn't catch up
whether it's safe or not to discard data from backing device. In the
case, only the lock it could rely on to synchronize swap slot freeing is
page table lock. Thus, this patch gets rid of the swap_slot_free_notify
function. With this patch, CPU A will see correct data.
CPU A CPU B
do_swap_page do_swap_page
SWP_SYNCHRONOUS_IO path SWP_SYNCHRONOUS_IO path
swap_readpage original data
pte_lock
map the original data
swap_free
swap_range_free
bd_disk->fops->swap_slot_free_notify
swap_readpage read zeroed data
pte_unlock
pte_lock
if (!pte_same)
goto out_nomap;
pte_unlock
return
on next refault will see mapped data by CPU B
The concern of the patch would increase memory consumption since it
could keep wasted memory with compressed form in zram as well as
uncompressed form in address space. However, most of cases of zram uses
no readahead and do_swap_page is followed by swap_free so it will free
the compressed form from in zram quickly.
Link: https://lkml.kernel.org/r/YjTVVxIAsnKAXjTd@google.com
Fixes:
|
||
 Juergen Gross
|
e553f62f10 |
mm, page_alloc: fix build_zonerefs_node()
Since commit |
||
 Marco Elver
|
2dfe63e61c |
mm, kfence: support kmem_dump_obj() for KFENCE objects
Calling kmem_obj_info() via kmem_dump_obj() on KFENCE objects has been producing garbage data due to the object not actually being maintained by SLAB or SLUB. Fix this by implementing __kfence_obj_info() that copies relevant information to struct kmem_obj_info when the object was allocated by KFENCE; this is called by a common kmem_obj_info(), which also calls the slab/slub/slob specific variant now called __kmem_obj_info(). For completeness, kmem_dump_obj() now displays if the object was allocated by KFENCE. Link: https://lore.kernel.org/all/20220323090520.GG16885@xsang-OptiPlex-9020/ Link: https://lkml.kernel.org/r/20220406131558.3558585-1-elver@google.com Fixes: |
||
 Vincenzo Frascino
|
b1add418d4 |
kasan: fix hw tags enablement when KUNIT tests are disabled
Kasan enables hw tags via kasan_enable_tagging() which based on the mode passed via kernel command line selects the correct hw backend. kasan_enable_tagging() is meant to be invoked indirectly via the cpu features framework of the architectures that support these backends. Currently the invocation of this function is guarded by CONFIG_KASAN_KUNIT_TEST which allows the enablement of the correct backend only when KUNIT tests are enabled in the kernel. This inconsistency was introduced in commit: |
||
 Axel Rasmussen
|
f9b141f936 |
mm/secretmem: fix panic when growing a memfd_secret
When one tries to grow an existing memfd_secret with ftruncate, one gets
a panic [1]. For example, doing the following reliably induces the
panic:
fd = memfd_secret();
ftruncate(fd, 10);
ptr = mmap(NULL, 10, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);
strcpy(ptr, "123456789");
munmap(ptr, 10);
ftruncate(fd, 20);
The basic reason for this is, when we grow with ftruncate, we call down
into simple_setattr, and then truncate_inode_pages_range, and eventually
we try to zero part of the memory. The normal truncation code does this
via the direct map (i.e., it calls page_address() and hands that to
memset()).
For memfd_secret though, we specifically don't map our pages via the
direct map (i.e. we call set_direct_map_invalid_noflush() on every
fault). So the address returned by page_address() isn't useful, and
when we try to memset() with it we panic.
This patch avoids the panic by implementing a custom setattr for
memfd_secret, which detects resizes specifically (setting the size for
the first time works just fine, since there are no existing pages to try
to zero), and rejects them with EINVAL.
One could argue growing should be supported, but I think that will
require a significantly more lengthy change. So, I propose a minimal
fix for the benefit of stable kernels, and then perhaps to extend
memfd_secret to support growing in a separate patch.
[1]:
BUG: unable to handle page fault for address: ffffa0a889277028
#PF: supervisor write access in kernel mode
#PF: error_code(0x0002) - not-present page
PGD afa01067 P4D afa01067 PUD 83f909067 PMD 83f8bf067 PTE 800ffffef6d88060
Oops: 0002 [#1] PREEMPT SMP DEBUG_PAGEALLOC PTI
CPU: 0 PID: 281 Comm: repro Not tainted 5.17.0-dbg-DEV #1
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1 04/01/2014
RIP: 0010:memset_erms+0x9/0x10
Code: c1 e9 03 40 0f b6 f6 48 b8 01 01 01 01 01 01 01 01 48 0f af c6 f3 48 ab 89 d1 f3 aa 4c 89 c8 c3 90 49 89 f9 40 88 f0 48 89 d1 <f3> aa 4c 89 c8 c3 90 49 89 fa 40 0f b6 ce 48 b8 01 01 01 01 01 01
RSP: 0018:ffffb932c09afbf0 EFLAGS: 00010246
RAX: 0000000000000000 RBX: ffffda63c4249dc0 RCX: 0000000000000fd8
RDX: 0000000000000fd8 RSI: 0000000000000000 RDI: ffffa0a889277028
RBP: ffffb932c09afc00 R08: 0000000000001000 R09: ffffa0a889277028
R10: 0000000000020023 R11: 0000000000000000 R12: ffffda63c4249dc0
R13: ffffa0a890d70d98 R14: 0000000000000028 R15: 0000000000000fd8
FS: 00007f7294899580(0000) GS:ffffa0af9bc00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffa0a889277028 CR3: 0000000107ef6006 CR4: 0000000000370ef0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
? zero_user_segments+0x82/0x190
truncate_inode_partial_folio+0xd4/0x2a0
truncate_inode_pages_range+0x380/0x830
truncate_setsize+0x63/0x80
simple_setattr+0x37/0x60
notify_change+0x3d8/0x4d0
do_sys_ftruncate+0x162/0x1d0
__x64_sys_ftruncate+0x1c/0x20
do_syscall_64+0x44/0xa0
entry_SYSCALL_64_after_hwframe+0x44/0xae
Modules linked in: xhci_pci xhci_hcd virtio_net net_failover failover virtio_blk virtio_balloon uhci_hcd ohci_pci ohci_hcd evdev ehci_pci ehci_hcd 9pnet_virtio 9p netfs 9pnet
CR2: ffffa0a889277028
[lkp@intel.com: secretmem_iops can be static]
Signed-off-by: kernel test robot <lkp@intel.com>
[axelrasmussen@google.com: return EINVAL]
Link: https://lkml.kernel.org/r/20220324210909.1843814-1-axelrasmussen@google.com
Link: https://lkml.kernel.org/r/20220412193023.279320-1-axelrasmussen@google.com
Signed-off-by: Axel Rasmussen <axelrasmussen@google.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: <stable@vger.kernel.org>
Cc: kernel test robot <lkp@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
||
 Hugh Dickins
|
1bdec44b1e |
tmpfs: fix regressions from wider use of ZERO_PAGE
Chuck Lever reported fsx-based xfstests generic 075 091 112 127 failing
when 5.18-rc1 NFS server exports tmpfs: bisected to recent tmpfs change.
Whilst nfsd_splice_action() does contain some questionable handling of
repeated pages, and Chuck was able to work around there, history from
Mark Hemment makes clear that there might be similar dangers elsewhere:
it was not a good idea for me to pass ZERO_PAGE down to unknown actors.
Revert shmem_file_read_iter() to using ZERO_PAGE for holes only when
iter_is_iovec(); in other cases, use the more natural iov_iter_zero()
instead of copy_page_to_iter().
We would use iov_iter_zero() throughout, but the x86 clear_user() is not
nearly so well optimized as copy to user (dd of 1T sparse tmpfs file
takes 57 seconds rather than 44 seconds).
And now pagecache_init() does not need to SetPageUptodate(ZERO_PAGE(0)):
which had caused boot failure on arm noMMU STM32F7 and STM32H7 boards
Link: https://lkml.kernel.org/r/9a978571-8648-e830-5735-1f4748ce2e30@google.com
Fixes:
|
||
|
Linus Torvalds
|
50c94de67c |
Merge tag 'locking_urgent_for_v5.18_rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull locking fixes from Borislav Petkov: - Allow the compiler to optimize away unused percpu accesses and change the local_lock_* macros back to inline functions - A couple of fixes to static call insn patching * tag 'locking_urgent_for_v5.18_rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: Revert "mm/page_alloc: mark pagesets as __maybe_unused" Revert "locking/local_lock: Make the empty local_lock_*() function a macro." x86/percpu: Remove volatile from arch_raw_cpu_ptr(). static_call: Remove __DEFINE_STATIC_CALL macro static_call: Properly initialise DEFINE_STATIC_CALL_RET0() static_call: Don't make __static_call_return0 static x86,static_call: Fix __static_call_return0 for i386 |