06 Mar, 2019
1 commit
-
commit cb6acd01e2e43fd8bad11155752b7699c3d0fb76 upstream.
hugetlb pages should only be migrated if they are 'active'. The
routines set/clear_page_huge_active() modify the active state of hugetlb
pages.When a new hugetlb page is allocated at fault time, set_page_huge_active
is called before the page is locked. Therefore, another thread could
race and migrate the page while it is being added to page table by the
fault code. This race is somewhat hard to trigger, but can be seen by
strategically adding udelay to simulate worst case scheduling behavior.
Depending on 'how' the code races, various BUG()s could be triggered.To address this issue, simply delay the set_page_huge_active call until
after the page is successfully added to the page table.Hugetlb pages can also be leaked at migration time if the pages are
associated with a file in an explicitly mounted hugetlbfs filesystem.
For example, consider a two node system with 4GB worth of huge pages
available. A program mmaps a 2G file in a hugetlbfs filesystem. It
then migrates the pages associated with the file from one node to
another. When the program exits, huge page counts are as follows:node0
1024 free_hugepages
1024 nr_hugepagesnode1
0 free_hugepages
1024 nr_hugepagesFilesystem Size Used Avail Use% Mounted on
nodev 4.0G 2.0G 2.0G 50% /var/opt/hugepoolThat is as expected. 2G of huge pages are taken from the free_hugepages
counts, and 2G is the size of the file in the explicitly mounted
filesystem. If the file is then removed, the counts become:node0
1024 free_hugepages
1024 nr_hugepagesnode1
1024 free_hugepages
1024 nr_hugepagesFilesystem Size Used Avail Use% Mounted on
nodev 4.0G 2.0G 2.0G 50% /var/opt/hugepoolNote that the filesystem still shows 2G of pages used, while there
actually are no huge pages in use. The only way to 'fix' the filesystem
accounting is to unmount the filesystemIf a hugetlb page is associated with an explicitly mounted filesystem,
this information in contained in the page_private field. At migration
time, this information is not preserved. To fix, simply transfer
page_private from old to new page at migration time if necessary.There is a related race with removing a huge page from a file and
migration. When a huge page is removed from the pagecache, the
page_mapping() field is cleared, yet page_private remains set until the
page is actually freed by free_huge_page(). A page could be migrated
while in this state. However, since page_mapping() is not set the
hugetlbfs specific routine to transfer page_private is not called and we
leak the page count in the filesystem.To fix that, check for this condition before migrating a huge page. If
the condition is detected, return EBUSY for the page.Link: http://lkml.kernel.org/r/74510272-7319-7372-9ea6-ec914734c179@oracle.com
Link: http://lkml.kernel.org/r/20190212221400.3512-1-mike.kravetz@oracle.com
Fixes: bcc54222309c ("mm: hugetlb: introduce page_huge_active")
Signed-off-by: Mike Kravetz
Reviewed-by: Naoya Horiguchi
Cc: Michal Hocko
Cc: Andrea Arcangeli
Cc: "Kirill A . Shutemov"
Cc: Mel Gorman
Cc: Davidlohr Bueso
Cc:
[mike.kravetz@oracle.com: v2]
Link: http://lkml.kernel.org/r/7534d322-d782-8ac6-1c8d-a8dc380eb3ab@oracle.com
[mike.kravetz@oracle.com: update comment and changelog]
Link: http://lkml.kernel.org/r/420bcfd6-158b-38e4-98da-26d0cd85bd01@oracle.com
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
Signed-off-by: Greg Kroah-Hartman
23 Aug, 2018
1 commit
-
Rather than in vm_area_alloc(). To ensure that the various oddball
stack-based vmas are in a good state. Some of the callers were zeroing
them out, others were not.Acked-by: Kirill A. Shutemov
Cc: Russell King
Cc: Dmitry Vyukov
Cc: Oleg Nesterov
Cc: Andrea Arcangeli
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
14 Aug, 2018
1 commit
-
Pull vfs open-related updates from Al Viro:
- "do we need fput() or put_filp()" rules are gone - it's always fput()
now. We keep track of that state where it belongs - in ->f_mode.- int *opened mess killed - in finish_open(), in ->atomic_open()
instances and in fs/namei.c code around do_last()/lookup_open()/atomic_open().- alloc_file() wrappers with saner calling conventions are introduced
(alloc_file_clone() and alloc_file_pseudo()); callers converted, with
much simplification.- while we are at it, saner calling conventions for path_init() and
link_path_walk(), simplifying things inside fs/namei.c (both on
open-related paths and elsewhere).* 'work.open3' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (40 commits)
few more cleanups of link_path_walk() callers
allow link_path_walk() to take ERR_PTR()
make path_init() unconditionally paired with terminate_walk()
document alloc_file() changes
make alloc_file() static
do_shmat(): grab shp->shm_file earlier, switch to alloc_file_clone()
new helper: alloc_file_clone()
create_pipe_files(): switch the first allocation to alloc_file_pseudo()
anon_inode_getfile(): switch to alloc_file_pseudo()
hugetlb_file_setup(): switch to alloc_file_pseudo()
ocxlflash_getfile(): switch to alloc_file_pseudo()
cxl_getfile(): switch to alloc_file_pseudo()
... and switch shmem_file_setup() to alloc_file_pseudo()
__shmem_file_setup(): reorder allocations
new wrapper: alloc_file_pseudo()
kill FILE_{CREATED,OPENED}
switch atomic_open() and lookup_open() to returning 0 in all success cases
document ->atomic_open() changes
->atomic_open(): return 0 in all success cases
get rid of 'opened' in path_openat() and the helpers downstream
...
27 Jul, 2018
1 commit
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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
Acked-by: Linus Torvalds
Reviewed-by: Andrew Morton
Cc: Dmitry Vyukov
Cc: Oleg Nesterov
Cc: Andrea Arcangeli
Cc:
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
12 Jul, 2018
2 commits
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Acked-by: Linus Torvalds
Signed-off-by: Al Viro -
... so that it could set both ->f_flags and ->f_mode, without callers
having to set ->f_flags manually.Signed-off-by: Al Viro
06 Apr, 2018
1 commit
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This is a fix for a regression in 32 bit kernels caused by an invalid
check for pgoff overflow in hugetlbfs mmap setup. The check incorrectly
specified that the size of a loff_t was the same as the size of a long.
The regression prevents mapping hugetlbfs files at offsets greater than
4GB on 32 bit kernels.On 32 bit kernels conversion from a page based unsigned long can not
overflow a loff_t byte offset. Therefore, skip this check if
sizeof(unsigned long) != sizeof(loff_t).Link: http://lkml.kernel.org/r/20180330145402.5053-1-mike.kravetz@oracle.com
Fixes: 63489f8e8211 ("hugetlbfs: check for pgoff value overflow")
Reported-by: Dan Rue
Signed-off-by: Mike Kravetz
Tested-by: Anders Roxell
Cc: Michal Hocko
Cc: Yisheng Xie
Cc: "Kirill A . Shutemov"
Cc: Nic Losby
Cc:
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
23 Mar, 2018
1 commit
-
A vma with vm_pgoff large enough to overflow a loff_t type when
converted to a byte offset can be passed via the remap_file_pages system
call. The hugetlbfs mmap routine uses the byte offset to calculate
reservations and file size.A sequence such as:
mmap(0x20a00000, 0x600000, 0, 0x66033, -1, 0);
remap_file_pages(0x20a00000, 0x600000, 0, 0x20000000000000, 0);will result in the following when task exits/file closed,
kernel BUG at mm/hugetlb.c:749!
Call Trace:
hugetlbfs_evict_inode+0x2f/0x40
evict+0xcb/0x190
__dentry_kill+0xcb/0x150
__fput+0x164/0x1e0
task_work_run+0x84/0xa0
exit_to_usermode_loop+0x7d/0x80
do_syscall_64+0x18b/0x190
entry_SYSCALL_64_after_hwframe+0x3d/0xa2The overflowed pgoff value causes hugetlbfs to try to set up a mapping
with a negative range (end < start) that leaves invalid state which
causes the BUG.The previous overflow fix to this code was incomplete and did not take
the remap_file_pages system call into account.[mike.kravetz@oracle.com: v3]
Link: http://lkml.kernel.org/r/20180309002726.7248-1-mike.kravetz@oracle.com
[akpm@linux-foundation.org: include mmdebug.h]
[akpm@linux-foundation.org: fix -ve left shift count on sh]
Link: http://lkml.kernel.org/r/20180308210502.15952-1-mike.kravetz@oracle.com
Fixes: 045c7a3f53d9 ("hugetlbfs: fix offset overflow in hugetlbfs mmap")
Signed-off-by: Mike Kravetz
Reported-by: Nic Losby
Acked-by: Michal Hocko
Cc: "Kirill A . Shutemov"
Cc: Yisheng Xie
Cc:
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
01 Feb, 2018
2 commits
-
Implements memfd sealing, similar to shmem:
- WRITE: deny fallocate(PUNCH_HOLE). mmap() write is denied in
memfd_add_seals(). write() doesn't exist for hugetlbfs.
- SHRINK: added similar check as shmem_setattr()
- GROW: added similar check as shmem_setattr() & shmem_fallocate()Except write() operation that doesn't exist with hugetlbfs, that should
make sealing as close as it can be to shmem support.Link: http://lkml.kernel.org/r/20171107122800.25517-5-marcandre.lureau@redhat.com
Signed-off-by: Marc-André Lureau
Reviewed-by: Mike Kravetz
Cc: Andrea Arcangeli
Cc: Hugh Dickins
Cc: Michal Hocko
Cc: David Herrmann
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
hugetlbfs inode information will need to be accessed by code in
mm/shmem.c for file sealing operations. Move inode information
definition from .c file to header for needed access.Link: http://lkml.kernel.org/r/20171107122800.25517-4-marcandre.lureau@redhat.com
Signed-off-by: Marc-André Lureau
Reviewed-by: Mike Kravetz
Cc: Andrea Arcangeli
Cc: Hugh Dickins
Cc: Michal Hocko
Cc: David Herrmann
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
30 Nov, 2017
1 commit
-
hugetlfs_fallocate() currently performs put_page() before unlock_page().
This scenario opens a small time window, from the time the page is added
to the page cache, until it is unlocked, in which the page might be
removed from the page-cache by another core. If the page is removed
during this time windows, it might cause a memory corruption, as the
wrong page will be unlocked.It is arguable whether this scenario can happen in a real system, and
there are several mitigating factors. The issue was found by code
inspection (actually grep), and not by actually triggering the flow.
Yet, since putting the page before unlocking is incorrect it should be
fixed, if only to prevent future breakage or someone copy-pasting this
code.Mike said:
"I am of the opinion that this does not need to be sent to stable.
Although the ordering is current code is incorrect, there is no way
for this to be a problem with current locking. In addition, I verified
that the perhaps bigger issue with sys_fadvise64(POSIX_FADV_DONTNEED)
for hugetlbfs and other filesystems is addressed in 3a77d214807c ("mm:
fadvise: avoid fadvise for fs without backing device")"Link: http://lkml.kernel.org/r/20170826191124.51642-1-namit@vmware.com
Fixes: 70c3547e36f5c ("hugetlbfs: add hugetlbfs_fallocate()")
Signed-off-by: Nadav Amit
Reviewed-by: Mike Kravetz
Acked-by: Michal Hocko
Cc: Eric Biggers
Cc: Mike Kravetz
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
16 Nov, 2017
2 commits
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Every pagevec_init user claims the pages being released are hot even in
cases where it is unlikely the pages are hot. As no one cares about the
hotness of pages being released to the allocator, just ditch the
parameter.No performance impact is expected as the overhead is marginal. The
parameter is removed simply because it is a bit stupid to have a useless
parameter copied everywhere.Link: http://lkml.kernel.org/r/20171018075952.10627-6-mgorman@techsingularity.net
Signed-off-by: Mel Gorman
Acked-by: Vlastimil Babka
Cc: Andi Kleen
Cc: Dave Chinner
Cc: Dave Hansen
Cc: Jan Kara
Cc: Johannes Weiner
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
There is no need to have a local return code set with -EINVAL when both
the conditions following it return error codes appropriately. Just
remove the redundant one.Link: http://lkml.kernel.org/r/20170929145444.17611-1-khandual@linux.vnet.ibm.com
Signed-off-by: Anshuman Khandual
Reviewed-by: Mike Kravetz
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
03 Nov, 2017
1 commit
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Calling madvise(MADV_HWPOISON) on a hugetlbfs page will result in bad
(negative) reserved huge page counts. This may not happen immediately,
but may happen later when the underlying file is removed or filesystem
unmounted. For example:AnonHugePages: 0 kB
ShmemHugePages: 0 kB
HugePages_Total: 1
HugePages_Free: 0
HugePages_Rsvd: 18446744073709551615
HugePages_Surp: 0
Hugepagesize: 2048 kBIn routine hugetlbfs_error_remove_page(), hugetlb_fix_reserve_counts is
called after remove_huge_page. hugetlb_fix_reserve_counts is designed
to only be called/used only if a failure is returned from
hugetlb_unreserve_pages. Therefore, call hugetlb_unreserve_pages as
required and only call hugetlb_fix_reserve_counts in the unlikely event
that hugetlb_unreserve_pages returns an error.Link: http://lkml.kernel.org/r/20171019230007.17043-2-mike.kravetz@oracle.com
Fixes: 78bb920344b8 ("mm: hwpoison: dissolve in-use hugepage in unrecoverable memory error")
Signed-off-by: Mike Kravetz
Acked-by: Naoya Horiguchi
Cc: Michal Hocko
Cc: Aneesh Kumar
Cc: Anshuman Khandual
Cc:
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
09 Sep, 2017
2 commits
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Allow interval trees to quickly check for overlaps to avoid unnecesary
tree lookups in interval_tree_iter_first().As of this patch, all interval tree flavors will require using a
'rb_root_cached' such that we can have the leftmost node easily
available. While most users will make use of this feature, those with
special functions (in addition to the generic insert, delete, search
calls) will avoid using the cached option as they can do funky things
with insertions -- for example, vma_interval_tree_insert_after().[jglisse@redhat.com: fix deadlock from typo vm_lock_anon_vma()]
Link: http://lkml.kernel.org/r/20170808225719.20723-1-jglisse@redhat.com
Link: http://lkml.kernel.org/r/20170719014603.19029-12-dave@stgolabs.net
Signed-off-by: Davidlohr Bueso
Signed-off-by: Jérôme Glisse
Acked-by: Christian König
Acked-by: Peter Zijlstra (Intel)
Acked-by: Doug Ledford
Acked-by: Michael S. Tsirkin
Cc: David Airlie
Cc: Jason Wang
Cc: Christian Benvenuti
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Introduce a new migration mode that allow to offload the copy to a device
DMA engine. This changes the workflow of migration and not all
address_space migratepage callback can support this.This is intended to be use by migrate_vma() which itself is use for thing
like HMM (see include/linux/hmm.h).No additional per-filesystem migratepage testing is needed. I disables
MIGRATE_SYNC_NO_COPY in all problematic migratepage() callback and i
added comment in those to explain why (part of this patch). The commit
message is unclear it should say that any callback that wish to support
this new mode need to be aware of the difference in the migration flow
from other mode.Some of these callbacks do extra locking while copying (aio, zsmalloc,
balloon, ...) and for DMA to be effective you want to copy multiple
pages in one DMA operations. But in the problematic case you can not
easily hold the extra lock accross multiple call to this callback.Usual flow is:
For each page {
1 - lock page
2 - call migratepage() callback
3 - (extra locking in some migratepage() callback)
4 - migrate page state (freeze refcount, update page cache, buffer
head, ...)
5 - copy page
6 - (unlock any extra lock of migratepage() callback)
7 - return from migratepage() callback
8 - unlock page
}The new mode MIGRATE_SYNC_NO_COPY:
1 - lock multiple pages
For each page {
2 - call migratepage() callback
3 - abort in all problematic migratepage() callback
4 - migrate page state (freeze refcount, update page cache, buffer
head, ...)
} // finished all calls to migratepage() callback
5 - DMA copy multiple pages
6 - unlock all the pagesTo support MIGRATE_SYNC_NO_COPY in the problematic case we would need a
new callback migratepages() (for instance) that deals with multiple
pages in one transaction.Because the problematic cases are not important for current usage I did
not wanted to complexify this patchset even more for no good reason.Link: http://lkml.kernel.org/r/20170817000548.32038-14-jglisse@redhat.com
Signed-off-by: Jérôme Glisse
Cc: Aneesh Kumar
Cc: Balbir Singh
Cc: Benjamin Herrenschmidt
Cc: Dan Williams
Cc: David Nellans
Cc: Evgeny Baskakov
Cc: Johannes Weiner
Cc: John Hubbard
Cc: Kirill A. Shutemov
Cc: Mark Hairgrove
Cc: Michal Hocko
Cc: Paul E. McKenney
Cc: Ross Zwisler
Cc: Sherry Cheung
Cc: Subhash Gutti
Cc: Vladimir Davydov
Cc: Bob Liu
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
07 Sep, 2017
3 commits
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All users of pagevec_lookup() and pagevec_lookup_range() now pass
PAGEVEC_SIZE as a desired number of pages.Just drop the argument.
Link: http://lkml.kernel.org/r/20170726114704.7626-11-jack@suse.cz
Signed-off-by: Jan Kara
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
We want only pages from given range in remove_inode_hugepages(). Use
pagevec_lookup_range() instead of pagevec_lookup().Link: http://lkml.kernel.org/r/20170726114704.7626-8-jack@suse.cz
Signed-off-by: Jan Kara
Reviewed-by: Mike Kravetz
Cc: Nadia Yvette Chambers
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Make pagevec_lookup() (and underlying find_get_pages()) update index to
the next page where iteration should continue. Most callers want this
and also pagevec_lookup_tag() already does this.Link: http://lkml.kernel.org/r/20170726114704.7626-3-jack@suse.cz
Signed-off-by: Jan Kara
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
16 Jul, 2017
1 commit
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Pull ->s_options removal from Al Viro:
"Preparations for fsmount/fsopen stuff (coming next cycle). Everything
gets moved to explicit ->show_options(), killing ->s_options off +
some cosmetic bits around fs/namespace.c and friends. Basically, the
stuff needed to work with fsmount series with minimum of conflicts
with other work.It's not strictly required for this merge window, but it would reduce
the PITA during the coming cycle, so it would be nice to have those
bits and pieces out of the way"* 'work.mount' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
isofs: Fix isofs_show_options()
VFS: Kill off s_options and helpers
orangefs: Implement show_options
9p: Implement show_options
isofs: Implement show_options
afs: Implement show_options
affs: Implement show_options
befs: Implement show_options
spufs: Implement show_options
bpf: Implement show_options
ramfs: Implement show_options
pstore: Implement show_options
omfs: Implement show_options
hugetlbfs: Implement show_options
VFS: Don't use save/replace_mount_options if not using generic_show_options
VFS: Provide empty name qstr
VFS: Make get_filesystem() return the affected filesystem
VFS: Clean up whitespace in fs/namespace.c and fs/super.c
Provide a function to create a NUL-terminated string from unterminated data
11 Jul, 2017
1 commit
-
Currently me_huge_page() relies on dequeue_hwpoisoned_huge_page() to
keep the error hugepage away from the system, which is OK but not good
enough because the hugepage still has a refcount and unpoison doesn't
work on the error hugepage (PageHWPoison flags are cleared but pages are
still leaked.) And there's "wasting health subpages" issue too. This
patch reworks on me_huge_page() to solve these issues.For hugetlb file, recently we have truncating code so let's use it in
hugetlbfs specific ->error_remove_page().For anonymous hugepage, it's helpful to dissolve the error page after
freeing it into free hugepage list. Migration entry and PageHWPoison in
the head page prevent the access to it.TODO: dissolve_free_huge_page() can fail but we don't considered it yet.
It's not critical (and at least no worse that now) because in such case
the error hugepage just stays in free hugepage list without being
dissolved. By virtue of PageHWPoison in head page, it's never allocated
to processes.[akpm@linux-foundation.org: fix unused var warnings]
Fixes: 23a003bfd23ea9ea0b7756b920e51f64b284b468 ("mm/madvise: pass return code of memory_failure() to userspace")
Link: http://lkml.kernel.org/r/20170417055948.GM31394@yexl-desktop
Link: http://lkml.kernel.org/r/1496305019-5493-8-git-send-email-n-horiguchi@ah.jp.nec.com
Signed-off-by: Naoya Horiguchi
Reported-by: kernel test robot
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
06 Jul, 2017
1 commit
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Implement the show_options superblock op for hugetlbfs as part of a bid to
get rid of s_options and generic_show_options() to make it easier to
implement a context-based mount where the mount options can be passed
individually over a file descriptor.Note that the uid and gid should possibly be displayed relative to the
viewer's user namespace.Signed-off-by: David Howells
cc: Nadia Yvette Chambers
Signed-off-by: Al Viro
19 Jun, 2017
1 commit
-
Stack guard page is a useful feature to reduce a risk of stack smashing
into a different mapping. We have been using a single page gap which
is sufficient to prevent having stack adjacent to a different mapping.
But this seems to be insufficient in the light of the stack usage in
userspace. E.g. glibc uses as large as 64kB alloca() in many commonly
used functions. Others use constructs liks gid_t buffer[NGROUPS_MAX]
which is 256kB or stack strings with MAX_ARG_STRLEN.This will become especially dangerous for suid binaries and the default
no limit for the stack size limit because those applications can be
tricked to consume a large portion of the stack and a single glibc call
could jump over the guard page. These attacks are not theoretical,
unfortunatelly.Make those attacks less probable by increasing the stack guard gap
to 1MB (on systems with 4k pages; but make it depend on the page size
because systems with larger base pages might cap stack allocations in
the PAGE_SIZE units) which should cover larger alloca() and VLA stack
allocations. It is obviously not a full fix because the problem is
somehow inherent, but it should reduce attack space a lot.One could argue that the gap size should be configurable from userspace,
but that can be done later when somebody finds that the new 1MB is wrong
for some special case applications. For now, add a kernel command line
option (stack_guard_gap) to specify the stack gap size (in page units).Implementation wise, first delete all the old code for stack guard page:
because although we could get away with accounting one extra page in a
stack vma, accounting a larger gap can break userspace - case in point,
a program run with "ulimit -S -v 20000" failed when the 1MB gap was
counted for RLIMIT_AS; similar problems could come with RLIMIT_MLOCK
and strict non-overcommit mode.Instead of keeping gap inside the stack vma, maintain the stack guard
gap as a gap between vmas: using vm_start_gap() in place of vm_start
(or vm_end_gap() in place of vm_end if VM_GROWSUP) in just those few
places which need to respect the gap - mainly arch_get_unmapped_area(),
and and the vma tree's subtree_gap support for that.Original-patch-by: Oleg Nesterov
Original-patch-by: Michal Hocko
Signed-off-by: Hugh Dickins
Acked-by: Michal Hocko
Tested-by: Helge Deller # parisc
Signed-off-by: Linus Torvalds
14 Apr, 2017
1 commit
-
If mmap() maps a file, it can be passed an offset into the file at which
the mapping is to start. Offset could be a negative value when
represented as a loff_t. The offset plus length will be used to update
the file size (i_size) which is also a loff_t.Validate the value of offset and offset + length to make sure they do
not overflow and appear as negative.Found by syzcaller with commit ff8c0c53c475 ("mm/hugetlb.c: don't call
region_abort if region_chg fails") applied. Prior to this commit, the
overflow would still occur but we would luckily return ENOMEM.To reproduce:
mmap(0, 0x2000, 0, 0x40021, 0xffffffffffffffffULL, 0x8000000000000000ULL);
Resulted in,
kernel BUG at mm/hugetlb.c:742!
Call Trace:
hugetlbfs_evict_inode+0x80/0xa0
evict+0x24a/0x620
iput+0x48f/0x8c0
dentry_unlink_inode+0x31f/0x4d0
__dentry_kill+0x292/0x5e0
dput+0x730/0x830
__fput+0x438/0x720
____fput+0x1a/0x20
task_work_run+0xfe/0x180
exit_to_usermode_loop+0x133/0x150
syscall_return_slowpath+0x184/0x1c0
entry_SYSCALL_64_fastpath+0xab/0xadFixes: ff8c0c53c475 ("mm/hugetlb.c: don't call region_abort if region_chg fails")
Link: http://lkml.kernel.org/r/1491951118-30678-1-git-send-email-mike.kravetz@oracle.com
Reported-by: Vegard Nossum
Signed-off-by: Mike Kravetz
Acked-by: Hillf Danton
Cc: Dmitry Vyukov
Cc: Michal Hocko
Cc: "Kirill A . Shutemov"
Cc: Andrey Ryabinin
Cc: Naoya Horiguchi
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
01 Apr, 2017
1 commit
-
Any time after inode allocation, destroy_inode can be called. The
hugetlbfs inode contains a shared_policy structure, and
mpol_free_shared_policy is unconditionally called as part of
hugetlbfs_destroy_inode. Initialize the policy as part of inode
allocation so that any quick (error path) calls to destroy_inode will be
handed an initialized policy.syzkaller fuzzer found this bug, that resulted in the following:
BUG: KASAN: user-memory-access in atomic_inc
include/asm-generic/atomic-instrumented.h:87 [inline] at addr
000000131730bd7a
BUG: KASAN: user-memory-access in __lock_acquire+0x21a/0x3a80
kernel/locking/lockdep.c:3239 at addr 000000131730bd7a
Write of size 4 by task syz-executor6/14086
CPU: 3 PID: 14086 Comm: syz-executor6 Not tainted 4.11.0-rc3+ #364
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011
Call Trace:
atomic_inc include/asm-generic/atomic-instrumented.h:87 [inline]
__lock_acquire+0x21a/0x3a80 kernel/locking/lockdep.c:3239
lock_acquire+0x1ee/0x590 kernel/locking/lockdep.c:3762
__raw_write_lock include/linux/rwlock_api_smp.h:210 [inline]
_raw_write_lock+0x33/0x50 kernel/locking/spinlock.c:295
mpol_free_shared_policy+0x43/0xb0 mm/mempolicy.c:2536
hugetlbfs_destroy_inode+0xca/0x120 fs/hugetlbfs/inode.c:952
alloc_inode+0x10d/0x180 fs/inode.c:216
new_inode_pseudo+0x69/0x190 fs/inode.c:889
new_inode+0x1c/0x40 fs/inode.c:918
hugetlbfs_get_inode+0x40/0x420 fs/hugetlbfs/inode.c:734
hugetlb_file_setup+0x329/0x9f0 fs/hugetlbfs/inode.c:1282
newseg+0x422/0xd30 ipc/shm.c:575
ipcget_new ipc/util.c:285 [inline]
ipcget+0x21e/0x580 ipc/util.c:639
SYSC_shmget ipc/shm.c:673 [inline]
SyS_shmget+0x158/0x230 ipc/shm.c:657
entry_SYSCALL_64_fastpath+0x1f/0xc2Analysis provided by Tetsuo Handa
Link: http://lkml.kernel.org/r/1490477850-7944-1-git-send-email-mike.kravetz@oracle.com
Signed-off-by: Mike Kravetz
Reported-by: Dmitry Vyukov
Acked-by: Hillf Danton
Cc: Tetsuo Handa
Cc: Michal Hocko
Cc: Dave Hansen
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
02 Mar, 2017
1 commit
-
…hed.h> into <linux/sched/signal.h>
Fix up affected files that include this signal functionality via sched.h.
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
25 Dec, 2016
1 commit
-
This was entirely automated, using the script by Al:
PATT='^[[:blank:]]*#[[:blank:]]*include[[:blank:]]*'
sed -i -e "s!$PATT!#include !" \
$(git grep -l "$PATT"|grep -v ^include/linux/uaccess.h)to do the replacement at the end of the merge window.
Requested-by: Al Viro
Signed-off-by: Linus Torvalds
11 Oct, 2016
2 commits
-
Pull more vfs updates from Al Viro:
">rename2() work from Miklos + current_time() from Deepa"* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
fs: Replace current_fs_time() with current_time()
fs: Replace CURRENT_TIME_SEC with current_time() for inode timestamps
fs: Replace CURRENT_TIME with current_time() for inode timestamps
fs: proc: Delete inode time initializations in proc_alloc_inode()
vfs: Add current_time() api
vfs: add note about i_op->rename changes to porting
fs: rename "rename2" i_op to "rename"
vfs: remove unused i_op->rename
fs: make remaining filesystems use .rename2
libfs: support RENAME_NOREPLACE in simple_rename()
fs: support RENAME_NOREPLACE for local filesystems
ncpfs: fix unused variable warning -
Pull misc vfs updates from Al Viro:
"Assorted misc bits and pieces.There are several single-topic branches left after this (rename2
series from Miklos, current_time series from Deepa Dinamani, xattr
series from Andreas, uaccess stuff from from me) and I'd prefer to
send those separately"* 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (39 commits)
proc: switch auxv to use of __mem_open()
hpfs: support FIEMAP
cifs: get rid of unused arguments of CIFSSMBWrite()
posix_acl: uapi header split
posix_acl: xattr representation cleanups
fs/aio.c: eliminate redundant loads in put_aio_ring_file
fs/internal.h: add const to ns_dentry_operations declaration
compat: remove compat_printk()
fs/buffer.c: make __getblk_slow() static
proc: unsigned file descriptors
fs/file: more unsigned file descriptors
fs: compat: remove redundant check of nr_segs
cachefiles: Fix attempt to read i_blocks after deleting file [ver #2]
cifs: don't use memcpy() to copy struct iov_iter
get rid of separate multipage fault-in primitives
fs: Avoid premature clearing of capabilities
fs: Give dentry to inode_change_ok() instead of inode
fuse: Propagate dentry down to inode_change_ok()
ceph: Propagate dentry down to inode_change_ok()
xfs: Propagate dentry down to inode_change_ok()
...
08 Oct, 2016
1 commit
-
When the huge page is added to the page cahce (huge_add_to_page_cache),
the page private flag will be cleared. since this code
(remove_inode_hugepages) will only be called for pages in the page
cahce, PagePrivate(page) will always be false.The patch remove the code without any functional change.
Link: http://lkml.kernel.org/r/1475113323-29368-1-git-send-email-zhongjiang@huawei.com
Signed-off-by: zhong jiang
Reviewed-by: Naoya Horiguchi
Reviewed-by: Mike Kravetz
Tested-by: Mike Kravetz
Acked-by: Michal Hocko
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
28 Sep, 2016
1 commit
-
CURRENT_TIME macro is not appropriate for filesystems as it
doesn't use the right granularity for filesystem timestamps.
Use current_time() instead.CURRENT_TIME is also not y2038 safe.
This is also in preparation for the patch that transitions
vfs timestamps to use 64 bit time and hence make them
y2038 safe. As part of the effort current_time() will be
extended to do range checks. Hence, it is necessary for all
file system timestamps to use current_time(). Also,
current_time() will be transitioned along with vfs to be
y2038 safe.Note that whenever a single call to current_time() is used
to change timestamps in different inodes, it is because they
share the same time granularity.Signed-off-by: Deepa Dinamani
Reviewed-by: Arnd Bergmann
Acked-by: Felipe Balbi
Acked-by: Steven Whitehouse
Acked-by: Ryusuke Konishi
Acked-by: David Sterba
Signed-off-by: Al Viro
22 Sep, 2016
1 commit
-
inode_change_ok() will be resposible for clearing capabilities and IMA
extended attributes and as such will need dentry. Give it as an argument
to inode_change_ok() instead of an inode. Also rename inode_change_ok()
to setattr_prepare() to better relect that it does also some
modifications in addition to checks.Reviewed-by: Christoph Hellwig
Signed-off-by: Jan Kara
05 Apr, 2016
2 commits
-
Mostly direct substitution with occasional adjustment or removing
outdated comments.Signed-off-by: Kirill A. Shutemov
Acked-by: Michal Hocko
Signed-off-by: Linus Torvalds -
PAGE_CACHE_{SIZE,SHIFT,MASK,ALIGN} macros were introduced *long* time
ago with promise that one day it will be possible to implement page
cache with bigger chunks than PAGE_SIZE.This promise never materialized. And unlikely will.
We have many places where PAGE_CACHE_SIZE assumed to be equal to
PAGE_SIZE. And it's constant source of confusion on whether
PAGE_CACHE_* or PAGE_* constant should be used in a particular case,
especially on the border between fs and mm.Global switching to PAGE_CACHE_SIZE != PAGE_SIZE would cause to much
breakage to be doable.Let's stop pretending that pages in page cache are special. They are
not.The changes are pretty straight-forward:
- << (PAGE_CACHE_SHIFT - PAGE_SHIFT) -> ;
- >> (PAGE_CACHE_SHIFT - PAGE_SHIFT) -> ;
- PAGE_CACHE_{SIZE,SHIFT,MASK,ALIGN} -> PAGE_{SIZE,SHIFT,MASK,ALIGN};
- page_cache_get() -> get_page();
- page_cache_release() -> put_page();
This patch contains automated changes generated with coccinelle using
script below. For some reason, coccinelle doesn't patch header files.
I've called spatch for them manually.The only adjustment after coccinelle is revert of changes to
PAGE_CAHCE_ALIGN definition: we are going to drop it later.There are few places in the code where coccinelle didn't reach. I'll
fix them manually in a separate patch. Comments and documentation also
will be addressed with the separate patch.virtual patch
@@
expression E;
@@
- E << (PAGE_CACHE_SHIFT - PAGE_SHIFT)
+ E@@
expression E;
@@
- E >> (PAGE_CACHE_SHIFT - PAGE_SHIFT)
+ E@@
@@
- PAGE_CACHE_SHIFT
+ PAGE_SHIFT@@
@@
- PAGE_CACHE_SIZE
+ PAGE_SIZE@@
@@
- PAGE_CACHE_MASK
+ PAGE_MASK@@
expression E;
@@
- PAGE_CACHE_ALIGN(E)
+ PAGE_ALIGN(E)@@
expression E;
@@
- page_cache_get(E)
+ get_page(E)@@
expression E;
@@
- page_cache_release(E)
+ put_page(E)Signed-off-by: Kirill A. Shutemov
Acked-by: Michal Hocko
Signed-off-by: Linus Torvalds
23 Jan, 2016
1 commit
-
parallel to mutex_{lock,unlock,trylock,is_locked,lock_nested},
inode_foo(inode) being mutex_foo(&inode->i_mutex).Please, use those for access to ->i_mutex; over the coming cycle
->i_mutex will become rwsem, with ->lookup() done with it held
only shared.Signed-off-by: Al Viro
16 Jan, 2016
3 commits
-
Page faults can race with fallocate hole punch. If a page fault happens
between the unmap and remove operations, the page is not removed and
remains within the hole. This is not the desired behavior. The race is
difficult to detect in user level code as even in the non-race case, a
page within the hole could be faulted back in before fallocate returns.
If userfaultfd is expanded to support hugetlbfs in the future, this race
will be easier to observe.If this race is detected and a page is mapped, the remove operation
(remove_inode_hugepages) will unmap the page before removing. The unmap
within remove_inode_hugepages occurs with the hugetlb_fault_mutex held
so that no other faults will be processed until the page is removed.The (unmodified) routine hugetlb_vmdelete_list was moved ahead of
remove_inode_hugepages to satisfy the new reference.[akpm@linux-foundation.org: move hugetlb_vmdelete_list()]
Signed-off-by: Mike Kravetz
Cc: Hugh Dickins
Cc: Naoya Horiguchi
Cc: Hillf Danton
Cc: Davidlohr Bueso
Cc: Dave Hansen
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Hillf Danton noticed bugs in the hugetlb_vmtruncate_list routine. The
argument end is of type pgoff_t. It was being converted to a vaddr
offset and passed to unmap_hugepage_range. However, end was also being
used as an argument to the vma_interval_tree_foreach controlling loop.
In addition, the conversion of end to vaddr offset was incorrect.hugetlb_vmtruncate_list is called as part of a file truncate or
fallocate hole punch operation.When truncating a hugetlbfs file, this bug could prevent some pages from
being unmapped. This is possible if there are multiple vmas mapping the
file, and there is a sufficiently sized hole between the mappings. The
size of the hole between two vmas (A,B) must be such that the starting
virtual address of B is greater than (ending virtual address of A <<
PAGE_SHIFT). In this case, the pages in B would not be unmapped. If
pages are not properly unmapped during truncate, the following BUG is
hit:kernel BUG at fs/hugetlbfs/inode.c:428!
In the fallocate hole punch case, this bug could prevent pages from
being unmapped as in the truncate case. However, for hole punch the
result is that unmapped pages will not be removed during the operation.
For hole punch, it is also possible that more pages than desired will be
unmapped. This unnecessary unmapping will cause page faults to
reestablish the mappings on subsequent page access.Fixes: 1bfad99ab (" hugetlbfs: hugetlb_vmtruncate_list() needs to take a range")Reported-by: Hillf Danton
Signed-off-by: Mike Kravetz
Cc: Hugh Dickins
Cc: Naoya Horiguchi
Cc: Davidlohr Bueso
Cc: Dave Hansen
Cc: [4.3]
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Dmitry Vyukov has reported[1] possible deadlock (triggered by his
syzkaller fuzzer):Possible unsafe locking scenario:
CPU0 CPU1
---- ----
lock(&hugetlbfs_i_mmap_rwsem_key);
lock(&mapping->i_mmap_rwsem);
lock(&hugetlbfs_i_mmap_rwsem_key);
lock(&mapping->i_mmap_rwsem);Both traces points to mm_take_all_locks() as a source of the problem.
It doesn't take care about ordering or hugetlbfs_i_mmap_rwsem_key (aka
mapping->i_mmap_rwsem for hugetlb mapping) vs. i_mmap_rwsem.huge_pmd_share() does memory allocation under hugetlbfs_i_mmap_rwsem_key
and allocator can take i_mmap_rwsem if it hit reclaim. So we need to
take i_mmap_rwsem from all hugetlb VMAs before taking i_mmap_rwsem from
rest of VMAs.The patch also documents locking order for hugetlbfs_i_mmap_rwsem_key.
[1] http://lkml.kernel.org/r/CACT4Y+Zu95tBs-0EvdiAKzUOsb4tczRRfCRTpLr4bg_OP9HuVg@mail.gmail.com
Signed-off-by: Kirill A. Shutemov
Reported-by: Dmitry Vyukov
Reviewed-by: Michal Hocko
Cc: Peter Zijlstra
Cc: Andrea Arcangeli
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
15 Jan, 2016
2 commits
-
The Kconfig currently controlling compilation of this code is:
config HUGETLBFS
bool "HugeTLB file system support"...meaning that it currently is not being built as a module by anyone.
Lets remove the modular code that is essentially orphaned, so that when
reading the driver there is no doubt it is builtin-only.Since module_init translates to device_initcall in the non-modular case,
the init ordering gets moved to earlier levels when we use the more
appropriate initcalls here.Originally I had the fs part and the mm part as separate commits, just
by happenstance of the nature of how I detected these non-modular use
cases. But that can possibly introduce regressions if the patch merge
ordering puts the fs part 1st -- as the 0-day testing reported a splat
at mount time.Investigating with "initcall_debug" showed that the delta was
init_hugetlbfs_fs being called _before_ hugetlb_init instead of after. So
both the fs change and the mm change are here together.In addition, it worked before due to luck of link order, since they were
both in the same initcall category. So we now have the fs part using
fs_initcall, and the mm part using subsys_initcall, which puts it one
bucket earlier. It now passes the basic sanity test that failed in
earlier 0-day testing.We delete the MODULE_LICENSE tag and capture that information at the top
of the file alongside author comments, etc.We don't replace module.h with init.h since the file already has that.
Also note that MODULE_ALIAS is a no-op for non-modular code.Signed-off-by: Paul Gortmaker
Reported-by: kernel test robot
Cc: Nadia Yvette Chambers
Cc: Alexander Viro
Cc: Naoya Horiguchi
Reviewed-by: Mike Kravetz
Cc: David Rientjes
Cc: Hillf Danton
Acked-by: Davidlohr Bueso
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
When running the SPECint_rate gcc on some very large boxes it was
noticed that the system was spending lots of time in
mpol_shared_policy_lookup(). The gamess benchmark can also show it and
is what I mostly used to chase down the issue since the setup for that I
found to be easier.To be clear the binaries were on tmpfs because of disk I/O requirements.
We then used text replication to avoid icache misses and having all the
copies banging on the memory where the instruction code resides. This
results in us hitting a bottleneck in mpol_shared_policy_lookup() since
lookup is serialised by the shared_policy lock.I have only reproduced this on very large (3k+ cores) boxes. The
problem starts showing up at just a few hundred ranks getting worse
until it threatens to livelock once it gets large enough. For example
on the gamess benchmark at 128 ranks this area consumes only ~1% of
time, at 512 ranks it consumes nearly 13%, and at 2k ranks it is over
90%.To alleviate the contention in this area I converted the spinlock to an
rwlock. This allows a large number of lookups to happen simultaneously.
The results were quite good reducing this consumtion at max ranks to
around 2%.[akpm@linux-foundation.org: tidy up code comments]
Signed-off-by: Nathan Zimmer
Acked-by: David Rientjes
Acked-by: Vlastimil Babka
Cc: Nadia Yvette Chambers
Cc: Naoya Horiguchi
Cc: Mel Gorman
Cc: "Aneesh Kumar K.V"
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
