Pull x86 PTI updates from Thomas Gleixner:
"The Speck brigade sadly provides yet another large set of patches
destroying the perfomance which we carefully built and preserved
- PTI support for 32bit PAE. The missing counter part to the 64bit
PTI code implemented by Joerg.
- A set of fixes for the Global Bit mechanics for non PCID CPUs which
were setting the Global Bit too widely and therefore possibly
exposing interesting memory needlessly.
- Protection against userspace-userspace SpectreRSB
- Support for the upcoming Enhanced IBRS mode, which is preferred
over IBRS. Unfortunately we dont know the performance impact of
this, but it's expected to be less horrible than the IBRS
hammering.
- Cleanups and simplifications"
* 'x86/pti' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (60 commits)
x86/mm/pti: Move user W+X check into pti_finalize()
x86/relocs: Add __end_rodata_aligned to S_REL
x86/mm/pti: Clone kernel-image on PTE level for 32 bit
x86/mm/pti: Don't clear permissions in pti_clone_pmd()
x86/mm/pti: Fix 32 bit PCID check
x86/mm/init: Remove freed kernel image areas from alias mapping
x86/mm/init: Add helper for freeing kernel image pages
x86/mm/init: Pass unconverted symbol addresses to free_init_pages()
mm: Allow non-direct-map arguments to free_reserved_area()
x86/mm/pti: Clear Global bit more aggressively
x86/speculation: Support Enhanced IBRS on future CPUs
x86/speculation: Protect against userspace-userspace spectreRSB
x86/kexec: Allocate 8k PGDs for PTI
Revert "perf/core: Make sure the ring-buffer is mapped in all page-tables"
x86/mm: Remove in_nmi() warning from vmalloc_fault()
x86/entry/32: Check for VM86 mode in slow-path check
perf/core: Make sure the ring-buffer is mapped in all page-tables
x86/pti: Check the return value of pti_user_pagetable_walk_pmd()
x86/pti: Check the return value of pti_user_pagetable_walk_p4d()
x86/entry/32: Add debug code to check entry/exit CR3
...
Pull x86 mm updates from Thomas Gleixner:
- Make lazy TLB mode even lazier to avoid pointless switch_mm()
operations, which reduces CPU load by 1-2% for memcache workloads
- Small cleanups and improvements all over the place
* 'x86-mm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/mm: Remove redundant check for kmem_cache_create()
arm/asm/tlb.h: Fix build error implicit func declaration
x86/mm/tlb: Make clear_asid_other() static
x86/mm/tlb: Skip atomic operations for 'init_mm' in switch_mm_irqs_off()
x86/mm/tlb: Always use lazy TLB mode
x86/mm/tlb: Only send page table free TLB flush to lazy TLB CPUs
x86/mm/tlb: Make lazy TLB mode lazier
x86/mm/tlb: Restructure switch_mm_irqs_off()
x86/mm/tlb: Leave lazy TLB mode at page table free time
mm: Allocate the mm_cpumask (mm->cpu_bitmap[]) dynamically based on nr_cpu_ids
x86/mm: Add TLB purge to free pmd/pte page interfaces
ioremap: Update pgtable free interfaces with addr
x86/mm: Disable ioremap free page handling on x86-PAE
ioremap_prot() can return NULL which could lead to an oops.
Link: http://lkml.kernel.org/r/1533195441-58594-1-git-send-email-chenjie6@huawei.com
Signed-off-by: chen jie <chenjie6@huawei.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Li Zefan <lizefan@huawei.com>
Cc: chenjie <chenjie6@huawei.com>
Cc: Yang Shi <shy828301@gmail.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
free_reserved_area() takes pointers as arguments to show which addresses
should be freed. However, it does this in a somewhat ambiguous way. If it
gets a kernel direct map address, it always works. However, if it gets an
address that is part of the kernel image alias mapping, it can fail.
It fails if all of the following happen:
* The specified address is part of the kernel image alias
* Poisoning is requested (forcing a memset())
* The address is in a read-only portion of the kernel image
The memset() fails on the read-only mapping, of course.
free_reserved_area() *is* called both on the direct map and on kernel image
alias addresses. We've just lucked out thus far that the kernel image
alias areas it gets used on are read-write. I'm fairly sure this has been
just a happy accident.
It is quite easy to make free_reserved_area() work for all cases: just
convert the address to a direct map address before doing the memset(), and
do this unconditionally. There is little chance of a regression here
because we previously did a virt_to_page() on the address for the memset,
so we know these are not highmem pages for which virt_to_page() would fail.
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: keescook@google.com
Cc: aarcange@redhat.com
Cc: jgross@suse.com
Cc: jpoimboe@redhat.com
Cc: gregkh@linuxfoundation.org
Cc: peterz@infradead.org
Cc: hughd@google.com
Cc: torvalds@linux-foundation.org
Cc: bp@alien8.de
Cc: luto@kernel.org
Cc: ak@linux.intel.com
Cc: Kees Cook <keescook@google.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Hugh Dickins <hughd@google.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Andi Kleen <ak@linux.intel.com>
Link: https://lkml.kernel.org/r/20180802225826.1287AE3E@viggo.jf.intel.com
Commit 05ea88608d ("mm, hugetlbfs: introduce ->pagesize() to
vm_operations_struct") adds a new ->pagesize() function to
hugetlb_vm_ops, intended to cover all hugetlbfs backed files.
With System V shared memory model, if "huge page" is specified, the
"shared memory" is backed by hugetlbfs files, but the mappings initiated
via shmget/shmat have their original vm_ops overwritten with shm_vm_ops,
so we need to add a ->pagesize function to shm_vm_ops. Otherwise,
vma_kernel_pagesize() returns PAGE_SIZE given a hugetlbfs backed vma,
result in below BUG:
fs/hugetlbfs/inode.c
443 if (unlikely(page_mapped(page))) {
444 BUG_ON(truncate_op);
resulting in
hugetlbfs: oracle (4592): Using mlock ulimits for SHM_HUGETLB is deprecated
------------[ cut here ]------------
kernel BUG at fs/hugetlbfs/inode.c:444!
Modules linked in: nfsv3 rpcsec_gss_krb5 nfsv4 ...
CPU: 35 PID: 5583 Comm: oracle_5583_sbt Not tainted 4.14.35-1829.el7uek.x86_64 #2
RIP: 0010:remove_inode_hugepages+0x3db/0x3e2
....
Call Trace:
hugetlbfs_evict_inode+0x1e/0x3e
evict+0xdb/0x1af
iput+0x1a2/0x1f7
dentry_unlink_inode+0xc6/0xf0
__dentry_kill+0xd8/0x18d
dput+0x1b5/0x1ed
__fput+0x18b/0x216
____fput+0xe/0x10
task_work_run+0x90/0xa7
exit_to_usermode_loop+0xdd/0x116
do_syscall_64+0x187/0x1ae
entry_SYSCALL_64_after_hwframe+0x150/0x0
[jane.chu@oracle.com: relocate comment]
Link: http://lkml.kernel.org/r/20180731044831.26036-1-jane.chu@oracle.com
Link: http://lkml.kernel.org/r/20180727211727.5020-1-jane.chu@oracle.com
Fixes: 05ea88608d ("mm, hugetlbfs: introduce ->pagesize() to vm_operations_struct")
Signed-off-by: Jane Chu <jane.chu@oracle.com>
Suggested-by: Mike Kravetz <mike.kravetz@oracle.com>
Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
Acked-by: Davidlohr Bueso <dave@stgolabs.net>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Jérôme Glisse <jglisse@redhat.com>
Cc: Manfred Spraul <manfred@colorfullife.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
In case of memcg_online_kmem() failure, memcg_cgroup::id remains hashed
in mem_cgroup_idr even after memcg memory is freed. This leads to leak
of ID in mem_cgroup_idr.
This patch adds removal into mem_cgroup_css_alloc(), which fixes the
problem. For better readability, it adds a generic helper which is used
in mem_cgroup_alloc() and mem_cgroup_id_put_many() as well.
Link: http://lkml.kernel.org/r/152354470916.22460.14397070748001974638.stgit@localhost.localdomain
Fixes 73f576c04b ("mm: memcontrol: fix cgroup creation failure after many small jobs")
Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: Michal Hocko <mhocko@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Delete the old VM_BUG_ON_VMA() from zap_pmd_range(), which asserted
that mmap_sem must be held when splitting an "anonymous" vma there.
Whether that's still strictly true nowadays is not entirely clear,
but the danger of sometimes crashing on the BUG is now fairly clear.
Even with the new stricter rules for anonymous vma marking, the
condition it checks for can possible trigger. Commit 44960f2a7b
("staging: ashmem: Fix SIGBUS crash when traversing mmaped ashmem
pages") is good, and originally I thought it was safe from that
VM_BUG_ON_VMA(), because the /dev/ashmem fd exposed to the user is
disconnected from the vm_file in the vma, and madvise(,,MADV_REMOVE)
insists on VM_SHARED.
But after I read John's earlier mail, drawing attention to the
vfs_fallocate() in there: I may be wrong, and I don't know if Android
has THP in the config anyway, but it looks to me like an
unmap_mapping_range() from ashmem's vfs_fallocate() could hit precisely
the VM_BUG_ON_VMA(), once it's vma_is_anonymous().
Signed-off-by: Hugh Dickins <hughd@google.com>
Cc: John Stultz <john.stultz@linaro.org>
Cc: Kirill Shutemov <kirill.shutemov@linux.intel.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
/sys/../zswap/stored_pages keeps rising in a zswap test with
"zswap.max_pool_percent=0" parameter. But it should not compress or
store pages any more since there is no space in the compressed pool.
Reproduce steps:
1. Boot kernel with "zswap.enabled=1"
2. Set the max_pool_percent to 0
# echo 0 > /sys/module/zswap/parameters/max_pool_percent
3. Do memory stress test to see if some pages have been compressed
# stress --vm 1 --vm-bytes $mem_available"M" --timeout 60s
4. Watching the 'stored_pages' number increasing or not
The root cause is:
When zswap_max_pool_percent is set to 0 via kernel parameter,
zswap_is_full() will always return true due to zswap_shrink(). But if
the shinking is able to reclain a page successfully the code then
proceeds to compressing/storing another page, so the value of
stored_pages will keep changing.
To solve the issue, this patch adds a zswap_is_full() check again after
zswap_shrink() to make sure it's now under the max_pool_percent, and to
not compress/store if we reached the limit.
Link: http://lkml.kernel.org/r/20180530103936.17812-1-liwang@redhat.com
Signed-off-by: Li Wang <liwang@redhat.com>
Acked-by: Dan Streetman <ddstreet@ieee.org>
Cc: Seth Jennings <sjenning@redhat.com>
Cc: Huang Ying <huang.ying.caritas@gmail.com>
Cc: Yu Zhao <yuzhao@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Make sure to initialize all VMAs properly, not only those which come
from vm_area_cachep.
Link: http://lkml.kernel.org/r/20180724121139.62570-3-kirill.shutemov@linux.intel.com
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Like vm_area_dup(), it initializes the anon_vma_chain head, and the
basic mm pointer.
The rest of the fields end up being different for different users,
although the plan is to also initialize the 'vm_ops' field to a dummy
entry.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
.. and re-initialize th eanon_vma_chain head.
This removes some boiler-plate from the users, and also makes it clear
why it didn't need use the 'zalloc()' version.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The vm_area_struct is one of the most fundamental memory management
objects, but the management of it is entirely open-coded evertwhere,
ranging from allocation and freeing (using kmem_cache_[z]alloc and
kmem_cache_free) to initializing all the fields.
We want to unify this in order to end up having some unified
initialization of the vmas, and the first step to this is to at least
have basic allocation functions.
Right now those functions are literally just wrappers around the
kmem_cache_*() calls. This is a purely mechanical conversion:
# new vma:
kmem_cache_zalloc(vm_area_cachep, GFP_KERNEL) -> vm_area_alloc()
# copy old vma
kmem_cache_alloc(vm_area_cachep, GFP_KERNEL) -> vm_area_dup(old)
# free vma
kmem_cache_free(vm_area_cachep, vma) -> vm_area_free(vma)
to the point where the old vma passed in to the vm_area_dup() function
isn't even used yet (because I've left all the old manual initialization
alone).
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
It was reported that a kernel crash happened in mem_cgroup_iter(), which
can be triggered if the legacy cgroup-v1 non-hierarchical mode is used.
Unable to handle kernel paging request at virtual address 6b6b6b6b6b6b8f
......
Call trace:
mem_cgroup_iter+0x2e0/0x6d4
shrink_zone+0x8c/0x324
balance_pgdat+0x450/0x640
kswapd+0x130/0x4b8
kthread+0xe8/0xfc
ret_from_fork+0x10/0x20
mem_cgroup_iter():
......
if (css_tryget(css)) <-- crash here
break;
......
The crashing reason is that mem_cgroup_iter() uses the memcg object whose
pointer is stored in iter->position, which has been freed before and
filled with POISON_FREE(0x6b).
And the root cause of the use-after-free issue is that
invalidate_reclaim_iterators() fails to reset the value of iter->position
to NULL when the css of the memcg is released in non- hierarchical mode.
Link: http://lkml.kernel.org/r/1531994807-25639-1-git-send-email-jing.xia@unisoc.com
Fixes: 6df38689e0 ("mm: memcontrol: fix possible memcg leak due to interrupted reclaim")
Signed-off-by: Jing Xia <jing.xia.mail@gmail.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: <chunyan.zhang@unisoc.com>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
__split_huge_pmd_locked() must check if the cleared huge pmd was dirty,
and propagate that to PageDirty: otherwise, data may be lost when a huge
tmpfs page is modified then split then reclaimed.
How has this taken so long to be noticed? Because there was no problem
when the huge page is written by a write system call (shmem_write_end()
calls set_page_dirty()), nor when the page is allocated for a write fault
(fault_dirty_shared_page() calls set_page_dirty()); but when allocated for
a read fault (which MAP_POPULATE simulates), no set_page_dirty().
Link: http://lkml.kernel.org/r/alpine.LSU.2.11.1807111741430.1106@eggly.anvils
Fixes: d21b9e57c7 ("thp: handle file pages in split_huge_pmd()")
Signed-off-by: Hugh Dickins <hughd@google.com>
Reported-by: Ashwin Chaugule <ashwinch@google.com>
Reviewed-by: Yang Shi <yang.shi@linux.alibaba.com>
Reviewed-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: "Huang, Ying" <ying.huang@intel.com>
Cc: <stable@vger.kernel.org> [4.8+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Commit 26f09e9b3a ("mm/memblock: add memblock memory allocation apis")
introduced two new function definitions:
memblock_virt_alloc_try_nid_nopanic()
memblock_virt_alloc_try_nid()
and commit ea1f5f3712 ("mm: define memblock_virt_alloc_try_nid_raw")
introduced the following function definition:
memblock_virt_alloc_try_nid_raw()
This commit adds an include of header file <linux/bootmem.h> to provide
the missing function prototypes. This silences the following gcc warning
(W=1):
mm/memblock.c:1334:15: warning: no previous prototype for `memblock_virt_alloc_try_nid_raw' [-Wmissing-prototypes]
mm/memblock.c:1371:15: warning: no previous prototype for `memblock_virt_alloc_try_nid_nopanic' [-Wmissing-prototypes]
mm/memblock.c:1407:15: warning: no previous prototype for `memblock_virt_alloc_try_nid' [-Wmissing-prototypes]
Also adds #ifdef blockers to prevent compilation failure on mips/ia64
where CONFIG_NO_BOOTMEM=n as could be seen in commit commit 6cc22dc08a
("revert "mm/memblock: add missing include <linux/bootmem.h>"").
Because Makefile already does:
obj-$(CONFIG_HAVE_MEMBLOCK) += memblock.o
The #ifdef has been simplified from:
#if defined(CONFIG_HAVE_MEMBLOCK) && defined(CONFIG_NO_BOOTMEM)
to simply:
#if defined(CONFIG_NO_BOOTMEM)
Link: http://lkml.kernel.org/r/20180626184422.24974-1-malat@debian.org
Signed-off-by: Mathieu Malaterre <malat@debian.org>
Suggested-by: Tony Luck <tony.luck@intel.com>
Suggested-by: Michal Hocko <mhocko@kernel.org>
Acked-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Andy discovered that speculative memory accesses while in lazy
TLB mode can crash a system, when a CPU tries to dereference a
speculative access using memory contents that used to be valid
page table memory, but have since been reused for something else
and point into la-la land.
The latter problem can be prevented in two ways. The first is to
always send a TLB shootdown IPI to CPUs in lazy TLB mode, while
the second one is to only send the TLB shootdown at page table
freeing time.
The second should result in fewer IPIs, since operationgs like
mprotect and madvise are very common with some workloads, but
do not involve page table freeing. Also, on munmap, batching
of page table freeing covers much larger ranges of virtual
memory than the batching of unmapped user pages.
Tested-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Rik van Riel <riel@surriel.com>
Acked-by: Dave Hansen <dave.hansen@intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: efault@gmx.de
Cc: kernel-team@fb.com
Cc: luto@kernel.org
Link: http://lkml.kernel.org/r/20180716190337.26133-3-riel@surriel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
The mm_struct always contains a cpumask bitmap, regardless of
CONFIG_CPUMASK_OFFSTACK. That means the first step can be to
simplify things, and simply have one bitmask at the end of the
mm_struct for the mm_cpumask.
This does necessitate moving everything else in mm_struct into
an anonymous sub-structure, which can be randomized when struct
randomization is enabled.
The second step is to determine the correct size for the
mm_struct slab object from the size of the mm_struct
(excluding the CPU bitmap) and the size the cpumask.
For init_mm we can simply allocate the maximum size this
kernel is compiled for, since we only have one init_mm
in the system, anyway.
Pointer magic by Mike Galbraith, to evade -Wstringop-overflow
getting confused by the dynamically sized array.
Tested-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Rik van Riel <riel@surriel.com>
Signed-off-by: Mike Galbraith <efault@gmx.de>
Signed-off-by: Rik van Riel <riel@surriel.com>
Acked-by: Dave Hansen <dave.hansen@intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: kernel-team@fb.com
Cc: luto@kernel.org
Link: http://lkml.kernel.org/r/20180716190337.26133-2-riel@surriel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Moving zero_resv_unavail before memmap_init_zone(), caused a regression on
x86-32.
The cause is that we access struct pages before they are allocated when
CONFIG_FLAT_NODE_MEM_MAP is used.
free_area_init_nodes()
zero_resv_unavail()
mm_zero_struct_page(pfn_to_page(pfn)); <- struct page is not alloced
free_area_init_node()
if CONFIG_FLAT_NODE_MEM_MAP
alloc_node_mem_map()
memblock_virt_alloc_node_nopanic() <- struct page alloced here
On the other hand memblock_virt_alloc_node_nopanic() zeroes all the memory
that it returns, so we do not need to do zero_resv_unavail() here.
Fixes: e181ae0c5d ("mm: zero unavailable pages before memmap init")
Signed-off-by: Pavel Tatashin <pasha.tatashin@oracle.com>
Tested-by: Matt Hart <matt@mattface.org>
Acked-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Merge misc fixes from Andrew Morton:
"11 fixes"
* emailed patches form Andrew Morton <akpm@linux-foundation.org>:
reiserfs: fix buffer overflow with long warning messages
checkpatch: fix duplicate invalid vsprintf pointer extension '%p<foo>' messages
mm: do not bug_on on incorrect length in __mm_populate()
mm/memblock.c: do not complain about top-down allocations for !MEMORY_HOTREMOVE
fs, elf: make sure to page align bss in load_elf_library
x86/purgatory: add missing FORCE to Makefile target
net/9p/client.c: put refcount of trans_mod in error case in parse_opts()
mm: allow arch to supply p??_free_tlb functions
autofs: fix slab out of bounds read in getname_kernel()
fs/proc/task_mmu.c: fix Locked field in /proc/pid/smaps*
mm: do not drop unused pages when userfaultd is running
syzbot has noticed that a specially crafted library can easily hit
VM_BUG_ON in __mm_populate
kernel BUG at mm/gup.c:1242!
invalid opcode: 0000 [#1] SMP
CPU: 2 PID: 9667 Comm: a.out Not tainted 4.18.0-rc3 #644
Hardware name: VMware, Inc. VMware Virtual Platform/440BX Desktop Reference Platform, BIOS 6.00 05/19/2017
RIP: 0010:__mm_populate+0x1e2/0x1f0
Code: 55 d0 65 48 33 14 25 28 00 00 00 89 d8 75 21 48 83 c4 20 5b 41 5c 41 5d 41 5e 41 5f 5d c3 e8 75 18 f1 ff 0f 0b e8 6e 18 f1 ff <0f> 0b 31 db eb c9 e8 93 06 e0 ff 0f 1f 00 55 48 89 e5 53 48 89 fb
Call Trace:
vm_brk_flags+0xc3/0x100
vm_brk+0x1f/0x30
load_elf_library+0x281/0x2e0
__ia32_sys_uselib+0x170/0x1e0
do_fast_syscall_32+0xca/0x420
entry_SYSENTER_compat+0x70/0x7f
The reason is that the length of the new brk is not page aligned when we
try to populate the it. There is no reason to bug on that though.
do_brk_flags already aligns the length properly so the mapping is
expanded as it should. All we need is to tell mm_populate about it.
Besides that there is absolutely no reason to to bug_on in the first
place. The worst thing that could happen is that the last page wouldn't
get populated and that is far from putting system into an inconsistent
state.
Fix the issue by moving the length sanitization code from do_brk_flags
up to vm_brk_flags. The only other caller of do_brk_flags is brk
syscall entry and it makes sure to provide the proper length so t here
is no need for sanitation and so we can use do_brk_flags without it.
Also remove the bogus BUG_ONs.
[osalvador@techadventures.net: fix up vm_brk_flags s@request@len@]
Link: http://lkml.kernel.org/r/20180706090217.GI32658@dhcp22.suse.cz
Signed-off-by: Michal Hocko <mhocko@suse.com>
Reported-by: syzbot <syzbot+5dcb560fe12aa5091c06@syzkaller.appspotmail.com>
Tested-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Cc: Zi Yan <zi.yan@cs.rutgers.edu>
Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Michael S. Tsirkin <mst@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: "Huang, Ying" <ying.huang@intel.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Mike Rapoport is converting architectures from bootmem to nobootmem
allocator. While doing so for m68k Geert has noticed that he gets a
scary looking warning:
WARNING: CPU: 0 PID: 0 at mm/memblock.c:230
memblock_find_in_range_node+0x11c/0x1be
memblock: bottom-up allocation failed, memory hotunplug may be affected
Modules linked in:
CPU: 0 PID: 0 Comm: swapper Not tainted
4.18.0-rc3-atari-01343-gf2fb5f2e09a97a3c-dirty #7
Call Trace: __warn+0xa8/0xc2
kernel_pg_dir+0x0/0x1000
netdev_lower_get_next+0x2/0x22
warn_slowpath_fmt+0x2e/0x36
memblock_find_in_range_node+0x11c/0x1be
memblock_find_in_range_node+0x11c/0x1be
memblock_find_in_range_node+0x0/0x1be
vprintk_func+0x66/0x6e
memblock_virt_alloc_internal+0xd0/0x156
netdev_lower_get_next+0x2/0x22
netdev_lower_get_next+0x2/0x22
kernel_pg_dir+0x0/0x1000
memblock_virt_alloc_try_nid_nopanic+0x58/0x7a
netdev_lower_get_next+0x2/0x22
kernel_pg_dir+0x0/0x1000
kernel_pg_dir+0x0/0x1000
EXPTBL+0x234/0x400
EXPTBL+0x234/0x400
alloc_node_mem_map+0x4a/0x66
netdev_lower_get_next+0x2/0x22
free_area_init_node+0xe2/0x29e
EXPTBL+0x234/0x400
paging_init+0x430/0x462
kernel_pg_dir+0x0/0x1000
printk+0x0/0x1a
EXPTBL+0x234/0x400
setup_arch+0x1b8/0x22c
start_kernel+0x4a/0x40a
_sinittext+0x344/0x9e8
The warning is basically saying that a top-down allocation can break
memory hotremove because memblock allocation is not movable. But m68k
doesn't even support MEMORY_HOTREMOVE so there is no point to warn about
it.
Make the warning conditional only to configurations that care.
Link: http://lkml.kernel.org/r/20180706061750.GH32658@dhcp22.suse.cz
Signed-off-by: Michal Hocko <mhocko@suse.com>
Reported-by: Geert Uytterhoeven <geert@linux-m68k.org>
Tested-by: Geert Uytterhoeven <geert@linux-m68k.org>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Mike Rapoport <rppt@linux.vnet.ibm.com>
Cc: Greg Ungerer <gerg@linux-m68k.org>
Cc: Sam Creasey <sammy@sammy.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
KVM guests on s390 can notify the host of unused pages. This can result
in pte_unused callbacks to be true for KVM guest memory.
If a page is unused (checked with pte_unused) we might drop this page
instead of paging it. This can have side-effects on userfaultd, when
the page in question was already migrated:
The next access of that page will trigger a fault and a user fault
instead of faulting in a new and empty zero page. As QEMU does not
expect a userfault on an already migrated page this migration will fail.
The most straightforward solution is to ignore the pte_unused hint if a
userfault context is active for this VMA.
Link: http://lkml.kernel.org/r/20180703171854.63981-1-borntraeger@de.ibm.com
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Mike Rapoport <rppt@linux.vnet.ibm.com>
Cc: Janosch Frank <frankja@linux.ibm.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Cornelia Huck <cohuck@redhat.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
We must zero struct pages for memory that is not backed by physical
memory, or kernel does not have access to.
Recently, there was a change which zeroed all memmap for all holes in
e820. Unfortunately, it introduced a bug that is discussed here:
https://www.spinics.net/lists/linux-mm/msg156764.html
Linus, also saw this bug on his machine, and confirmed that reverting
commit 124049decb ("x86/e820: put !E820_TYPE_RAM regions into
memblock.reserved") fixes the issue.
The problem is that we incorrectly zero some struct pages after they
were setup.
The fix is to zero unavailable struct pages prior to initializing of
struct pages.
A more detailed fix should come later that would avoid double zeroing
cases: one in __init_single_page(), the other one in
zero_resv_unavail().
Fixes: 124049decb ("x86/e820: put !E820_TYPE_RAM regions into memblock.reserved")
Signed-off-by: Pavel Tatashin <pasha.tatashin@oracle.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
If struct page is poisoned, and uninitialized access is detected via
PF_POISONED_CHECK(page) dump_page() is called to output the page. But,
the dump_page() itself accesses struct page to determine how to print
it, and therefore gets into a recursive loop.
For example:
dump_page()
__dump_page()
PageSlab(page)
PF_POISONED_CHECK(page)
VM_BUG_ON_PGFLAGS(PagePoisoned(page), page)
dump_page() recursion loop.
Link: http://lkml.kernel.org/r/20180702180536.2552-1-pasha.tatashin@oracle.com
Fixes: f165b378bb ("mm: uninitialized struct page poisoning sanity checking")
Signed-off-by: Pavel Tatashin <pasha.tatashin@oracle.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
There is a special case that the size is "(N << KASAN_SHADOW_SCALE_SHIFT)
Pages plus X", the value of X is [1, KASAN_SHADOW_SCALE_SIZE-1]. The
operation "size >> KASAN_SHADOW_SCALE_SHIFT" will drop X, and the
roundup operation can not retrieve the missed one page. For example:
size=0x28006, PAGE_SIZE=0x1000, KASAN_SHADOW_SCALE_SHIFT=3, we will get
shadow_size=0x5000, but actually we need 6 pages.
shadow_size = round_up(size >> KASAN_SHADOW_SCALE_SHIFT, PAGE_SIZE);
This can lead to a kernel crash when kasan is enabled and the value of
mod->core_layout.size or mod->init_layout.size is like above. Because
the shadow memory of X has not been allocated and mapped.
move_module:
ptr = module_alloc(mod->core_layout.size);
...
memset(ptr, 0, mod->core_layout.size); //crashed
Unable to handle kernel paging request at virtual address ffff0fffff97b000
......
Call trace:
__asan_storeN+0x174/0x1a8
memset+0x24/0x48
layout_and_allocate+0xcd8/0x1800
load_module+0x190/0x23e8
SyS_finit_module+0x148/0x180
Link: http://lkml.kernel.org/r/1529659626-12660-1-git-send-email-thunder.leizhen@huawei.com
Signed-off-by: Zhen Lei <thunder.leizhen@huawei.com>
Reviewed-by: Dmitriy Vyukov <dvyukov@google.com>
Acked-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Hanjun Guo <guohanjun@huawei.com>
Cc: Libin <huawei.libin@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
When booting with very large numbers of gigantic (i.e. 1G) pages, the
operations in the loop of gather_bootmem_prealloc, and specifically
prep_compound_gigantic_page, takes a very long time, and can cause a
softlockup if enough pages are requested at boot.
For example booting with 3844 1G pages requires prepping
(set_compound_head, init the count) over 1 billion 4K tail pages, which
takes considerable time.
Add a cond_resched() to the outer loop in gather_bootmem_prealloc() to
prevent this lockup.
Tested: Booted with softlockup_panic=1 hugepagesz=1G hugepages=3844 and
no softlockup is reported, and the hugepages are reported as
successfully setup.
Link: http://lkml.kernel.org/r/20180627214447.260804-1-cannonmatthews@google.com
Signed-off-by: Cannon Matthews <cannonmatthews@google.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Andres Lagar-Cavilla <andreslc@google.com>
Cc: Peter Feiner <pfeiner@google.com>
Cc: Greg Thelen <gthelen@google.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
In kernel 4.17 I removed some code from dm-bufio that did slab cache
merging (commit 21bb13276768: "dm bufio: remove code that merges slab
caches") - both slab and slub support merging caches with identical
attributes, so dm-bufio now just calls kmem_cache_create and relies on
implicit merging.
This uncovered a bug in the slub subsystem - if we delete a cache and
immediatelly create another cache with the same attributes, it fails
because of duplicate filename in /sys/kernel/slab/. The slub subsystem
offloads freeing the cache to a workqueue - and if we create the new
cache before the workqueue runs, it complains because of duplicate
filename in sysfs.
This patch fixes the bug by moving the call of kobject_del from
sysfs_slab_remove_workfn to shutdown_cache. kobject_del must be called
while we hold slab_mutex - so that the sysfs entry is deleted before a
cache with the same attributes could be created.
Running device-mapper-test-suite with:
dmtest run --suite thin-provisioning -n /commit_failure_causes_fallback/
triggered:
Buffer I/O error on dev dm-0, logical block 1572848, async page read
device-mapper: thin: 253:1: metadata operation 'dm_pool_alloc_data_block' failed: error = -5
device-mapper: thin: 253:1: aborting current metadata transaction
sysfs: cannot create duplicate filename '/kernel/slab/:a-0000144'
CPU: 2 PID: 1037 Comm: kworker/u48:1 Not tainted 4.17.0.snitm+ #25
Hardware name: Supermicro SYS-1029P-WTR/X11DDW-L, BIOS 2.0a 12/06/2017
Workqueue: dm-thin do_worker [dm_thin_pool]
Call Trace:
dump_stack+0x5a/0x73
sysfs_warn_dup+0x58/0x70
sysfs_create_dir_ns+0x77/0x80
kobject_add_internal+0xba/0x2e0
kobject_init_and_add+0x70/0xb0
sysfs_slab_add+0xb1/0x250
__kmem_cache_create+0x116/0x150
create_cache+0xd9/0x1f0
kmem_cache_create_usercopy+0x1c1/0x250
kmem_cache_create+0x18/0x20
dm_bufio_client_create+0x1ae/0x410 [dm_bufio]
dm_block_manager_create+0x5e/0x90 [dm_persistent_data]
__create_persistent_data_objects+0x38/0x940 [dm_thin_pool]
dm_pool_abort_metadata+0x64/0x90 [dm_thin_pool]
metadata_operation_failed+0x59/0x100 [dm_thin_pool]
alloc_data_block.isra.53+0x86/0x180 [dm_thin_pool]
process_cell+0x2a3/0x550 [dm_thin_pool]
do_worker+0x28d/0x8f0 [dm_thin_pool]
process_one_work+0x171/0x370
worker_thread+0x49/0x3f0
kthread+0xf8/0x130
ret_from_fork+0x35/0x40
kobject_add_internal failed for :a-0000144 with -EEXIST, don't try to register things with the same name in the same directory.
kmem_cache_create(dm_bufio_buffer-16) failed with error -17
Link: http://lkml.kernel.org/r/alpine.LRH.2.02.1806151817130.6333@file01.intranet.prod.int.rdu2.redhat.com
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Reported-by: Mike Snitzer <snitzer@redhat.com>
Tested-by: Mike Snitzer <snitzer@redhat.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Revert commit c7f26ccfb2 ("mm/vmstat.c: fix vmstat_update() preemption
BUG"). Steven saw a "using smp_processor_id() in preemptible" message
and added a preempt_disable() section around it to keep it quiet. This
is not the right thing to do it does not fix the real problem.
vmstat_update() is invoked by a kworker on a specific CPU. This worker
it bound to this CPU. The name of the worker was "kworker/1:1" so it
should have been a worker which was bound to CPU1. A worker which can
run on any CPU would have a `u' before the first digit.
smp_processor_id() can be used in a preempt-enabled region as long as
the task is bound to a single CPU which is the case here. If it could
run on an arbitrary CPU then this is the problem we have an should seek
to resolve.
Not only this smp_processor_id() must not be migrated to another CPU but
also refresh_cpu_vm_stats() which might access wrong per-CPU variables.
Not to mention that other code relies on the fact that such a worker
runs on one specific CPU only.
Therefore revert that commit and we should look instead what broke the
affinity mask of the kworker.
Link: http://lkml.kernel.org/r/20180504104451.20278-1-bigeasy@linutronix.de
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Steven J. Hill <steven.hill@cavium.com>
Cc: Tejun Heo <htejun@gmail.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-----BEGIN PGP SIGNATURE-----
iQJEBAABCAAuFiEEwPw5LcreJtl1+l5K99NY+ylx4KYFAlsudKcQHGF4Ym9lQGtl
cm5lbC5kawAKCRD301j7KXHgphYXEAC0G+fJcLgue64LwLNjXksDUsoldqNWjTDZ
e3szwseN3Woe7t+Q9DwEUO48T421WhDYe3UY50EZF3Fz5yYLi0ggTeq4qsKgpaXx
80dUY9/STxFZUV/tKrYMz5xPjM3k5x+m8FTeGlFgyR77fbOZE6/8w9XPkpmQN/B2
ayyEPMgAR9aZKhtOU4TJY45O278b2Qdfd0s6XUsxDTwBoR1mTQqKhNnY38PrIA5s
wkhtKz5YRdq5tNhKt2IwYABpJ4HJ1Hz/FE6Fo1RNx+6vfxfEhsk2/DZBn0rzzGDj
kvSaVlPeQEu9SZdJGtb2sx26elVWdt5sqMORQ0zb1kVCochZiT1IO3Z81XCy2Y3u
5WVvOlgsGni9BWr/K+iiN/dc+cKoRPy0g/ib77XUiJHgIC+urUIr3XgcIiuP9GZc
cgCfF+6+GvRKLatSsDZSbns5cpgueJLNogZUyhs7oUouRIECo0DD9NnDAlHmaZYB
957bRd/ykE6QOvtxEsG0TWc3tgyHjJFQQ9ukb45VmzYVB8mITKOGLpceJaqzju9c
AnGyQDddK4fqOct1pgFsSA5C3V6OOVXDpUiFn3DTNoQZcu5HN2hMwEA/g/u5TnGD
N2sEwcu2WCoUjzsMEWFLmX8R4w8laZUDwkNSRC5tYzQEZpVDfmAsRtRcUHJdNLl/
zPj8QMAidA==
=hCgr
-----END PGP SIGNATURE-----
Merge tag 'for-linus-20180623' of git://git.kernel.dk/linux-block
Pull block fixes from Jens Axboe:
- Further timeout fixes. We aren't quite there yet, so expect another
round of fixes for that to completely close some of the IRQ vs
completion races. (Christoph/Bart)
- Set of NVMe fixes from the usual suspects, mostly error handling
- Two off-by-one fixes (Dan)
- Another bdi race fix (Jan)
- Fix nbd reconfigure with NBD_DISCONNECT_ON_CLOSE (Doron)
* tag 'for-linus-20180623' of git://git.kernel.dk/linux-block:
blk-mq: Fix timeout handling in case the timeout handler returns BLK_EH_DONE
bdi: Fix another oops in wb_workfn()
lightnvm: Remove depends on HAS_DMA in case of platform dependency
nvme-pci: limit max IO size and segments to avoid high order allocations
nvme-pci: move nvme_kill_queues to nvme_remove_dead_ctrl
nvme-fc: release io queues to allow fast fail
nbd: Add the nbd NBD_DISCONNECT_ON_CLOSE config flag.
block: sed-opal: Fix a couple off by one bugs
blk-mq-debugfs: Off by one in blk_mq_rq_state_name()
nvmet: reset keep alive timer in controller enable
nvme-rdma: don't override opts->queue_size
nvme-rdma: Fix command completion race at error recovery
nvme-rdma: fix possible free of a non-allocated async event buffer
nvme-rdma: fix possible double free condition when failing to create a controller
Revert "block: Add warning for bi_next not NULL in bio_endio()"
block: fix timeout changes for legacy request drivers
syzbot is reporting NULL pointer dereference at wb_workfn() [1] due to
wb->bdi->dev being NULL. And Dmitry confirmed that wb->state was
WB_shutting_down after wb->bdi->dev became NULL. This indicates that
unregister_bdi() failed to call wb_shutdown() on one of wb objects.
The problem is in cgwb_bdi_unregister() which does cgwb_kill() and thus
drops bdi's reference to wb structures before going through the list of
wbs again and calling wb_shutdown() on each of them. This way the loop
iterating through all wbs can easily miss a wb if that wb has already
passed through cgwb_remove_from_bdi_list() called from wb_shutdown()
from cgwb_release_workfn() and as a result fully shutdown bdi although
wb_workfn() for this wb structure is still running. In fact there are
also other ways cgwb_bdi_unregister() can race with
cgwb_release_workfn() leading e.g. to use-after-free issues:
CPU1 CPU2
cgwb_bdi_unregister()
cgwb_kill(*slot);
cgwb_release()
queue_work(cgwb_release_wq, &wb->release_work);
cgwb_release_workfn()
wb = list_first_entry(&bdi->wb_list, ...)
spin_unlock_irq(&cgwb_lock);
wb_shutdown(wb);
...
kfree_rcu(wb, rcu);
wb_shutdown(wb); -> oops use-after-free
We solve these issues by synchronizing writeback structure shutdown from
cgwb_bdi_unregister() with cgwb_release_workfn() using a new mutex. That
way we also no longer need synchronization using WB_shutting_down as the
mutex provides it for CONFIG_CGROUP_WRITEBACK case and without
CONFIG_CGROUP_WRITEBACK wb_shutdown() can be called only once from
bdi_unregister().
Reported-by: syzbot <syzbot+4a7438e774b21ddd8eca@syzkaller.appspotmail.com>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
The patch fixed a W=1 warning but broke the ia64 build:
CC mm/memblock.o
mm/memblock.c:1340: error: redefinition of `memblock_virt_alloc_try_nid_raw'
./include/linux/bootmem.h:335: error: previous definition of `memblock_virt_alloc_try_nid_raw' was here
Because inlcude/linux/bootmem.h says
#if defined(CONFIG_HAVE_MEMBLOCK) && defined(CONFIG_NO_BOOTMEM)
whereas mm/Makefile says
obj-$(CONFIG_HAVE_MEMBLOCK) += memblock.o
So revert 26f09e9b3a ("mm/memblock: add missing include
<linux/bootmem.h>") while a full fix can be worked on.
Fixes: 26f09e9b3a ("mm/memblock: add missing include <linux/bootmem.h>")
Reported-by: Tony Luck <tony.luck@gmail.com>
Cc: Mathieu Malaterre <malat@debian.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Commit e27be240df ("mm: memcg: make sure memory.events is uptodate
when waking pollers") converted most of memcg event counters to
per-memcg atomics, which made them less confusing for a user. The
"oom_kill" counter remained untouched, so now it behaves differently
than other counters (including "oom"). This adds nothing but confusion.
Let's fix this by adding the MEMCG_OOM_KILL event, and follow the
MEMCG_OOM approach.
This also removes a hack from count_memcg_event_mm(), introduced earlier
specially for the OOM_KILL counter.
[akpm@linux-foundation.org: fix for droppage of memcg-replace-mm-owner-with-mm-memcg.patch]
Link: http://lkml.kernel.org/r/20180508124637.29984-1-guro@fb.com
Signed-off-by: Roman Gushchin <guro@fb.com>
Acked-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
mm/*.c files use symbolic and octal styles for permissions.
Using octal and not symbolic permissions is preferred by many as more
readable.
https://lkml.org/lkml/2016/8/2/1945
Prefer the direct use of octal for permissions.
Done using
$ scripts/checkpatch.pl -f --types=SYMBOLIC_PERMS --fix-inplace mm/*.c
and some typing.
Before: $ git grep -P -w "0[0-7]{3,3}" mm | wc -l
44
After: $ git grep -P -w "0[0-7]{3,3}" mm | wc -l
86
Miscellanea:
o Whitespace neatening around these conversions.
Link: http://lkml.kernel.org/r/2e032ef111eebcd4c5952bae86763b541d373469.1522102887.git.joe@perches.com
Signed-off-by: Joe Perches <joe@perches.com>
Acked-by: David Rientjes <rientjes@google.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Commit 5d1904204c ("mremap: fix race between mremap() and page
cleanning") fixed races between mremap and other operations for both
file-backed and anonymous mappings. The file-backed was the most
critical as it allowed the possibility that data could be changed on a
physical page after page_mkclean returned which could trigger data loss
or data integrity issues.
A customer reported that the cost of the TLBs for anonymous regressions
was excessive and resulting in a 30-50% drop in performance overall
since this commit on a microbenchmark. Unfortunately I neither have
access to the test-case nor can I describe what it does other than
saying that mremap operations dominate heavily.
This patch removes the LATENCY_LIMIT to handle TLB flushes on a PMD
boundary instead of every 64 pages to reduce the number of TLB
shootdowns by a factor of 8 in the ideal case. LATENCY_LIMIT was almost
certainly used originally to limit the PTL hold times but the latency
savings are likely offset by the cost of IPIs in many cases. This patch
is not reported to completely restore performance but gets it within an
acceptable percentage. The given metric here is simply described as
"higher is better".
Baseline that was known good
002: Metric: 91.05
004: Metric: 109.45
008: Metric: 73.08
016: Metric: 58.14
032: Metric: 61.09
064: Metric: 57.76
128: Metric: 55.43
Current
001: Metric: 54.98
002: Metric: 56.56
004: Metric: 41.22
008: Metric: 35.96
016: Metric: 36.45
032: Metric: 35.71
064: Metric: 35.73
128: Metric: 34.96
With patch
001: Metric: 61.43
002: Metric: 81.64
004: Metric: 67.92
008: Metric: 51.67
016: Metric: 50.47
032: Metric: 52.29
064: Metric: 50.01
128: Metric: 49.04
So for low threads, it's not restored but for larger number of threads,
it's closer to the "known good" baseline.
Using a different mremap-intensive workload that is not representative
of the real workload there is little difference observed outside of
noise in the headline metrics However, the TLB shootdowns are reduced by
11% on average and at the peak, TLB shootdowns were reduced by 21%.
Interrupts were sampled every second while the workload ran to get those
figures. It's known that the figures will vary as the
non-representative load is non-deterministic.
An alternative patch was posted that should have significantly reduced
the TLB flushes but unfortunately it does not perform as well as this
version on the customer test case. If revisited, the two patches can
stack on top of each other.
Link: http://lkml.kernel.org/r/20180606183803.k7qaw2xnbvzshv34@techsingularity.net
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Nadav Amit <nadav.amit@gmail.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Aaron Lu <aaron.lu@intel.com>
Cc: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Commit 26f09e9b3a ("mm/memblock: add memblock memory allocation apis")
introduced two new function definitions:
memblock_virt_alloc_try_nid_nopanic()
memblock_virt_alloc_try_nid()
Commit ea1f5f3712 ("mm: define memblock_virt_alloc_try_nid_raw")
introduced the following function definition:
memblock_virt_alloc_try_nid_raw()
This commit adds an includeof header file <linux/bootmem.h> to provide
the missing function prototypes. Silence the following gcc warning
(W=1):
mm/memblock.c:1334:15: warning: no previous prototype for `memblock_virt_alloc_try_nid_raw' [-Wmissing-prototypes]
mm/memblock.c:1371:15: warning: no previous prototype for `memblock_virt_alloc_try_nid_nopanic' [-Wmissing-prototypes]
mm/memblock.c:1407:15: warning: no previous prototype for `memblock_virt_alloc_try_nid' [-Wmissing-prototypes]
Link: http://lkml.kernel.org/r/20180606194144.16990-1-malat@debian.org
Signed-off-by: Mathieu Malaterre <malat@debian.org>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The memcg kmem cache creation and deactivation (SLUB only) is
asynchronous. If a root kmem cache is destroyed whose memcg cache is in
the process of creation or deactivation, the kernel may crash.
Example of one such crash:
general protection fault: 0000 [#1] SMP PTI
CPU: 1 PID: 1721 Comm: kworker/14:1 Not tainted 4.17.0-smp
...
Workqueue: memcg_kmem_cache kmemcg_deactivate_workfn
RIP: 0010:has_cpu_slab
...
Call Trace:
? on_each_cpu_cond
__kmem_cache_shrink
kmemcg_cache_deact_after_rcu
kmemcg_deactivate_workfn
process_one_work
worker_thread
kthread
ret_from_fork+0x35/0x40
To fix this race, on root kmem cache destruction, mark the cache as
dying and flush the workqueue used for memcg kmem cache creation and
deactivation. SLUB's memcg kmem cache deactivation also includes RCU
callback and thus make sure all previous registered RCU callbacks have
completed as well.
[shakeelb@google.com: handle the RCU callbacks for SLUB deactivation]
Link: http://lkml.kernel.org/r/20180611192951.195727-1-shakeelb@google.com
[shakeelb@google.com: add more documentation, rename fields for readability]
Link: http://lkml.kernel.org/r/20180522201336.196994-1-shakeelb@google.com
[akpm@linux-foundation.org: fix build, per Shakeel]
[shakeelb@google.com: v3. Instead of refcount, flush the workqueue]
Link: http://lkml.kernel.org/r/20180530001204.183758-1-shakeelb@google.com
Link: http://lkml.kernel.org/r/20180521174116.171846-1-shakeelb@google.com
Signed-off-by: Shakeel Butt <shakeelb@google.com>
Acked-by: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Greg Thelen <gthelen@google.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Commit 570a335b8e ("swap_info: swap count continuations") introduces
COUNT_CONTINUED but refers to it incorrectly as SWAP_HAS_CONT in a
comment in swap_count. Fix it.
Link: http://lkml.kernel.org/r/20180612175919.30413-1-daniel.m.jordan@oracle.com
Fixes: 570a335b8e ("swap_info: swap count continuations")
Signed-off-by: Daniel Jordan <daniel.m.jordan@oracle.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: "Huang, Ying" <ying.huang@intel.com>
Cc: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
In our armv8a server(QDF2400), I noticed lots of WARN_ON caused by
PAGE_SIZE unaligned for rmap_item->address under memory pressure
tests(start 20 guests and run memhog in the host).
WARNING: CPU: 4 PID: 4641 at virt/kvm/arm/mmu.c:1826 kvm_age_hva_handler+0xc0/0xc8
CPU: 4 PID: 4641 Comm: memhog Tainted: G W 4.17.0-rc3+ #8
Call trace:
kvm_age_hva_handler+0xc0/0xc8
handle_hva_to_gpa+0xa8/0xe0
kvm_age_hva+0x4c/0xe8
kvm_mmu_notifier_clear_flush_young+0x54/0x98
__mmu_notifier_clear_flush_young+0x6c/0xa0
page_referenced_one+0x154/0x1d8
rmap_walk_ksm+0x12c/0x1d0
rmap_walk+0x94/0xa0
page_referenced+0x194/0x1b0
shrink_page_list+0x674/0xc28
shrink_inactive_list+0x26c/0x5b8
shrink_node_memcg+0x35c/0x620
shrink_node+0x100/0x430
do_try_to_free_pages+0xe0/0x3a8
try_to_free_pages+0xe4/0x230
__alloc_pages_nodemask+0x564/0xdc0
alloc_pages_vma+0x90/0x228
do_anonymous_page+0xc8/0x4d0
__handle_mm_fault+0x4a0/0x508
handle_mm_fault+0xf8/0x1b0
do_page_fault+0x218/0x4b8
do_translation_fault+0x90/0xa0
do_mem_abort+0x68/0xf0
el0_da+0x24/0x28
In rmap_walk_ksm, the rmap_item->address might still have the
STABLE_FLAG, then the start and end in handle_hva_to_gpa might not be
PAGE_SIZE aligned. Thus it will cause exceptions in handle_hva_to_gpa
on arm64.
This patch fixes it by ignoring (not removing) the low bits of address
when doing rmap_walk_ksm.
IMO, it should be backported to stable tree. the storm of WARN_ONs is
very easy for me to reproduce. More than that, I watched a panic (not
reproducible) as follows:
page:ffff7fe003742d80 count:-4871 mapcount:-2126053375 mapping: (null) index:0x0
flags: 0x1fffc00000000000()
raw: 1fffc00000000000 0000000000000000 0000000000000000 ffffecf981470000
raw: dead000000000100 dead000000000200 ffff8017c001c000 0000000000000000
page dumped because: nonzero _refcount
CPU: 29 PID: 18323 Comm: qemu-kvm Tainted: G W 4.14.15-5.hxt.aarch64 #1
Hardware name: <snip for confidential issues>
Call trace:
dump_backtrace+0x0/0x22c
show_stack+0x24/0x2c
dump_stack+0x8c/0xb0
bad_page+0xf4/0x154
free_pages_check_bad+0x90/0x9c
free_pcppages_bulk+0x464/0x518
free_hot_cold_page+0x22c/0x300
__put_page+0x54/0x60
unmap_stage2_range+0x170/0x2b4
kvm_unmap_hva_handler+0x30/0x40
handle_hva_to_gpa+0xb0/0xec
kvm_unmap_hva_range+0x5c/0xd0
I even injected a fault on purpose in kvm_unmap_hva_range by seting
size=size-0x200, the call trace is similar as above. So I thought the
panic is similarly caused by the root cause of WARN_ON.
Andrea said:
: It looks a straightforward safe fix, on x86 hva_to_gfn_memslot would
: zap those bits and hide the misalignment caused by the low metadata
: bits being erroneously left set in the address, but the arm code
: notices when that's the last page in the memslot and the hva_end is
: getting aligned and the size is below one page.
:
: I think the problem triggers in the addr += PAGE_SIZE of
: unmap_stage2_ptes that never matches end because end is aligned but
: addr is not.
:
: } while (pte++, addr += PAGE_SIZE, addr != end);
:
: x86 again only works on hva_start/hva_end after converting it to
: gfn_start/end and that being in pfn units the bits are zapped before
: they risk to cause trouble.
Jia He said:
: I've tested by myself in arm64 server (QDF2400,46 cpus,96G mem) Without
: this patch, the WARN_ON is very easy for reproducing. After this patch, I
: have run the same benchmarch for a whole day without any WARN_ONs
Link: http://lkml.kernel.org/r/1525403506-6750-1-git-send-email-hejianet@gmail.com
Signed-off-by: Jia He <jia.he@hxt-semitech.com>
Reviewed-by: Andrea Arcangeli <aarcange@redhat.com>
Tested-by: Jia He <hejianet@gmail.com>
Cc: Suzuki K Poulose <Suzuki.Poulose@arm.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Claudio Imbrenda <imbrenda@linux.vnet.ibm.com>
Cc: Arvind Yadav <arvind.yadav.cs@gmail.com>
Cc: Mike Rapoport <rppt@linux.vnet.ibm.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* DAX broke a fundamental assumption of truncate of file mapped pages.
The truncate path assumed that it is safe to disconnect a pinned page
from a file and let the filesystem reclaim the physical block. With DAX
the page is equivalent to the filesystem block. Introduce
dax_layout_busy_page() to enable filesystems to wait for pinned DAX
pages to be released. Without this wait a filesystem could allocate
blocks under active device-DMA to a new file.
* DAX arranges for the block layer to be bypassed and uses
dax_direct_access() + copy_to_iter() to satisfy read(2) calls.
However, the memcpy_mcsafe() facility is available through the pmem
block driver. In order to safely handle media errors, via the DAX
block-layer bypass, introduce copy_to_iter_mcsafe().
* Fix cache management policy relative to the ACPI NFIT Platform
Capabilities Structure to properly elide cache flushes when they are not
necessary. The table indicates whether CPU caches are power-fail
protected. Clarify that a deep flush is always performed on
REQ_{FUA,PREFLUSH} requests.
-----BEGIN PGP SIGNATURE-----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=4bfw
-----END PGP SIGNATURE-----
Merge tag 'libnvdimm-for-4.18' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm
Pull libnvdimm updates from Dan Williams:
"This adds a user for the new 'bytes-remaining' updates to
memcpy_mcsafe() that you already received through Ingo via the
x86-dax- for-linus pull.
Not included here, but still targeting this cycle, is support for
handling memory media errors (poison) consumed via userspace dax
mappings.
Summary:
- DAX broke a fundamental assumption of truncate of file mapped
pages. The truncate path assumed that it is safe to disconnect a
pinned page from a file and let the filesystem reclaim the physical
block. With DAX the page is equivalent to the filesystem block.
Introduce dax_layout_busy_page() to enable filesystems to wait for
pinned DAX pages to be released. Without this wait a filesystem
could allocate blocks under active device-DMA to a new file.
- DAX arranges for the block layer to be bypassed and uses
dax_direct_access() + copy_to_iter() to satisfy read(2) calls.
However, the memcpy_mcsafe() facility is available through the pmem
block driver. In order to safely handle media errors, via the DAX
block-layer bypass, introduce copy_to_iter_mcsafe().
- Fix cache management policy relative to the ACPI NFIT Platform
Capabilities Structure to properly elide cache flushes when they
are not necessary. The table indicates whether CPU caches are
power-fail protected. Clarify that a deep flush is always performed
on REQ_{FUA,PREFLUSH} requests"
* tag 'libnvdimm-for-4.18' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm: (21 commits)
dax: Use dax_write_cache* helpers
libnvdimm, pmem: Do not flush power-fail protected CPU caches
libnvdimm, pmem: Unconditionally deep flush on *sync
libnvdimm, pmem: Complete REQ_FLUSH => REQ_PREFLUSH
acpi, nfit: Remove ecc_unit_size
dax: dax_insert_mapping_entry always succeeds
libnvdimm, e820: Register all pmem resources
libnvdimm: Debug probe times
linvdimm, pmem: Preserve read-only setting for pmem devices
x86, nfit_test: Add unit test for memcpy_mcsafe()
pmem: Switch to copy_to_iter_mcsafe()
dax: Report bytes remaining in dax_iomap_actor()
dax: Introduce a ->copy_to_iter dax operation
uio, lib: Fix CONFIG_ARCH_HAS_UACCESS_MCSAFE compilation
xfs, dax: introduce xfs_break_dax_layouts()
xfs: prepare xfs_break_layouts() for another layout type
xfs: prepare xfs_break_layouts() to be called with XFS_MMAPLOCK_EXCL
mm, fs, dax: handle layout changes to pinned dax mappings
mm: fix __gup_device_huge vs unmap
mm: introduce MEMORY_DEVICE_FS_DAX and CONFIG_DEV_PAGEMAP_OPS
...
Merge updates from Andrew Morton:
- a few misc things
- ocfs2 updates
- v9fs updates
- MM
- procfs updates
- lib/ updates
- autofs updates
* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (118 commits)
autofs: small cleanup in autofs_getpath()
autofs: clean up includes
autofs: comment on selinux changes needed for module autoload
autofs: update MAINTAINERS entry for autofs
autofs: use autofs instead of autofs4 in documentation
autofs: rename autofs documentation files
autofs: create autofs Kconfig and Makefile
autofs: delete fs/autofs4 source files
autofs: update fs/autofs4/Makefile
autofs: update fs/autofs4/Kconfig
autofs: copy autofs4 to autofs
autofs4: use autofs instead of autofs4 everywhere
autofs4: merge auto_fs.h and auto_fs4.h
fs/binfmt_misc.c: do not allow offset overflow
checkpatch: improve patch recognition
lib/ucs2_string.c: add MODULE_LICENSE()
lib/mpi: headers cleanup
lib/percpu_ida.c: use _irqsave() instead of local_irq_save() + spin_lock
lib/idr.c: remove simple_ida_lock
lib/bitmap.c: micro-optimization for __bitmap_complement()
...
kvmalloc warned about incompatible gfp_mask to catch abusers (mostly
GFP_NOFS) with an intention that this will motivate authors of the code
to fix those. Linus argues that this just motivates people to do even
more hacks like
if (gfp == GFP_KERNEL)
kvmalloc
else
kmalloc
I haven't seen this happening much (Linus pointed to bucket_lock special
cases an atomic allocation but my git foo hasn't found much more) but it
is true that we can grow those in future. Therefore Linus suggested to
simply not fallback to vmalloc for incompatible gfp flags and rather
stick with the kmalloc path.
Link: http://lkml.kernel.org/r/20180601115329.27807-1-mhocko@kernel.org
Signed-off-by: Michal Hocko <mhocko@suse.com>
Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Tom Herbert <tom@quantonium.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
shmem/tmpfs uses pseudo vma to allocate page with correct NUMA policy.
The pseudo vma doesn't have vm_page_prot set. We are going to encode
encryption KeyID in vm_page_prot. Having garbage there causes problems.
Zero out all unused fields in the pseudo vma.
Link: http://lkml.kernel.org/r/20180531135602.20321-1-kirill.shutemov@linux.intel.com
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
In __alloc_pages_slowpath() we reset zonelist and preferred_zoneref for
allocations that can ignore memory policies. The zonelist is obtained
from current CPU's node. This is a problem for __GFP_THISNODE
allocations that want to allocate on a different node, e.g. because the
allocating thread has been migrated to a different CPU.
This has been observed to break SLAB in our 4.4-based kernel, because
there it relies on __GFP_THISNODE working as intended. If a slab page
is put on wrong node's list, then further list manipulations may corrupt
the list because page_to_nid() is used to determine which node's
list_lock should be locked and thus we may take a wrong lock and race.
Current SLAB implementation seems to be immune by luck thanks to commit
511e3a0588 ("mm/slab: make cache_grow() handle the page allocated on
arbitrary node") but there may be others assuming that __GFP_THISNODE
works as promised.
We can fix it by simply removing the zonelist reset completely. There
is actually no reason to reset it, because memory policies and cpusets
don't affect the zonelist choice in the first place. This was different
when commit 183f6371aa ("mm: ignore mempolicies when using
ALLOC_NO_WATERMARK") introduced the code, as mempolicies provided their
own restricted zonelists.
We might consider this for 4.17 although I don't know if there's
anything currently broken.
SLAB is currently not affected, but in kernels older than 4.7 that don't
yet have 511e3a0588 ("mm/slab: make cache_grow() handle the page
allocated on arbitrary node") it is. That's at least 4.4 LTS. Older
ones I'll have to check.
So stable backports should be more important, but will have to be
reviewed carefully, as the code went through many changes. BTW I think
that also the ac->preferred_zoneref reset is currently useless if we
don't also reset ac->nodemask from a mempolicy to NULL first (which we
probably should for the OOM victims etc?), but I would leave that for a
separate patch.
Link: http://lkml.kernel.org/r/20180525130853.13915-1-vbabka@suse.cz
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Fixes: 183f6371aa ("mm: ignore mempolicies when using ALLOC_NO_WATERMARK")
Acked-by: Mel Gorman <mgorman@techsingularity.net>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
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
jie@chenjie6@huwei.com
Dave Hansen
Jane Chu
Kirill Tkhai
Hugh Dickins
Li Wang
Kirill A. Shutemov
Jing Xia
Mathieu Malaterre
Rik van Riel
Pavel Tatashin
Michal Hocko
Christian Borntraeger
Zhen Lei
Cannon Matthews
Mikulas Patocka
Sebastian Andrzej Siewior
Jan Kara
Andrew Morton
Roman Gushchin
Joe Perches
Mel Gorman
Shakeel Butt
Daniel Jordan
Jia He
Kees Cook
Dan Williams
Vlastimil Babka