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commit f4cb767d76cf7ee72f97dd76f6cfa6c76a5edc89 upstream.
Trinity gets kernel BUG at mm/mmap.c:1963! in about 3 minutes of
mmap testing. That's the VM_BUG_ON(gap_end < gap_start) at the
end of unmapped_area_topdown(). Linus points out how MAP_FIXED
(which does not have to respect our stack guard gap intentions)
could result in gap_end below gap_start there. Fix that, and
the similar case in its alternative, unmapped_area().
Fixes: 1be7107fbe18 ("mm: larger stack guard gap, between vmas")
Reported-by: Dave Jones <davej@codemonkey.org.uk>
Debugged-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Hugh Dickins <hughd@google.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit bd726c90b6b8ce87602208701b208a208e6d5600 upstream.
Fix expand_upwards() on architectures with an upward-growing stack (parisc,
metag and partly IA-64) to allow the stack to reliably grow exactly up to
the address space limit given by TASK_SIZE.
Signed-off-by: Helge Deller <deller@gmx.de>
Acked-by: Hugh Dickins <hughd@google.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit 1be7107fbe18eed3e319a6c3e83c78254b693acb upstream.
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 <oleg@redhat.com>
Original-patch-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Hugh Dickins <hughd@google.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Tested-by: Helge Deller <deller@gmx.de> # parisc
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
[wt: backport to 4.11: adjust context]
[wt: backport to 4.9: adjust context ; kernel doc was not in admin-guide]
[wt: backport to 4.4: adjust context ; drop ppc hugetlb_radix changes]
Signed-off-by: Willy Tarreau <w@1wt.eu>
[gkh: minor build fixes for 4.4]
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit ef70762948dde012146926720b70e79736336764 upstream.
I saw need_resched() warnings when swapping on large swapfile (TBs)
because continuously allocating many pages in swap_cgroup_prepare() took
too long.
We already cond_resched when freeing page in swap_cgroup_swapoff(). Do
the same for the page allocation.
Link: http://lkml.kernel.org/r/20170604200109.17606-1-yuzhao@google.com
Signed-off-by: Yu Zhao <yuzhao@google.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Vladimir Davydov <vdavydov.dev@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit 7258ae5c5a2ce2f5969e8b18b881be40ab55433d upstream.
memory_failure() chooses a recovery action function based on the page
flags. For huge pages it uses the tail page flags which don't have
anything interesting set, resulting in:
> Memory failure: 0x9be3b4: Unknown page state
> Memory failure: 0x9be3b4: recovery action for unknown page: Failed
Instead, save a copy of the head page's flags if this is a huge page,
this means if there are no relevant flags for this tail page, we use the
head pages flags instead. This results in the me_huge_page() recovery
action being called:
> Memory failure: 0x9b7969: recovery action for huge page: Delayed
For hugepages that have not yet been allocated, this allows the hugepage
to be dequeued.
Fixes: 524fca1e7356 ("HWPOISON: fix misjudgement of page_action() for errors on mlocked pages")
Link: http://lkml.kernel.org/r/20170524130204.21845-1-james.morse@arm.com
Signed-off-by: James Morse <james.morse@arm.com>
Tested-by: Punit Agrawal <punit.agrawal@arm.com>
Acked-by: Punit Agrawal <punit.agrawal@arm.com>
Acked-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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[ Upstream commit 4f40c6e5627ea73b4e7c615c59631f38cc880885 ]
After much waiting I finally reproduced a KASAN issue, only to find my
trace-buffer empty of useful information because it got spooled out :/
Make kasan_report honour the /proc/sys/kernel/traceoff_on_warning
interface.
Link: http://lkml.kernel.org/r/20170125164106.3514-1-aryabinin@virtuozzo.com
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Acked-by: Alexander Potapenko <glider@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit 864b9a393dcb5aed09b8fd31b9bbda0fdda99374 upstream.
We have seen an early OOM killer invocation on ppc64 systems with
crashkernel=4096M:
kthreadd invoked oom-killer: gfp_mask=0x16040c0(GFP_KERNEL|__GFP_COMP|__GFP_NOTRACK), nodemask=7, order=0, oom_score_adj=0
kthreadd cpuset=/ mems_allowed=7
CPU: 0 PID: 2 Comm: kthreadd Not tainted 4.4.68-1.gd7fe927-default #1
Call Trace:
dump_stack+0xb0/0xf0 (unreliable)
dump_header+0xb0/0x258
out_of_memory+0x5f0/0x640
__alloc_pages_nodemask+0xa8c/0xc80
kmem_getpages+0x84/0x1a0
fallback_alloc+0x2a4/0x320
kmem_cache_alloc_node+0xc0/0x2e0
copy_process.isra.25+0x260/0x1b30
_do_fork+0x94/0x470
kernel_thread+0x48/0x60
kthreadd+0x264/0x330
ret_from_kernel_thread+0x5c/0xa4
Mem-Info:
active_anon:0 inactive_anon:0 isolated_anon:0
active_file:0 inactive_file:0 isolated_file:0
unevictable:0 dirty:0 writeback:0 unstable:0
slab_reclaimable:5 slab_unreclaimable:73
mapped:0 shmem:0 pagetables:0 bounce:0
free:0 free_pcp:0 free_cma:0
Node 7 DMA free:0kB min:0kB low:0kB high:0kB active_anon:0kB inactive_anon:0kB active_file:0kB inactive_file:0kB unevictable:0kB isolated(anon):0kB isolated(file):0kB present:52428800kB managed:110016kB mlocked:0kB dirty:0kB writeback:0kB mapped:0kB shmem:0kB slab_reclaimable:320kB slab_unreclaimable:4672kB kernel_stack:1152kB pagetables:0kB unstable:0kB bounce:0kB free_pcp:0kB local_pcp:0kB free_cma:0kB writeback_tmp:0kB pages_scanned:0 all_unreclaimable? yes
lowmem_reserve[]: 0 0 0 0
Node 7 DMA: 0*64kB 0*128kB 0*256kB 0*512kB 0*1024kB 0*2048kB 0*4096kB 0*8192kB 0*16384kB = 0kB
0 total pagecache pages
0 pages in swap cache
Swap cache stats: add 0, delete 0, find 0/0
Free swap = 0kB
Total swap = 0kB
819200 pages RAM
0 pages HighMem/MovableOnly
817481 pages reserved
0 pages cma reserved
0 pages hwpoisoned
the reason is that the managed memory is too low (only 110MB) while the
rest of the the 50GB is still waiting for the deferred intialization to
be done. update_defer_init estimates the initial memoty to initialize
to 2GB at least but it doesn't consider any memory allocated in that
range. In this particular case we've had
Reserving 4096MB of memory at 128MB for crashkernel (System RAM: 51200MB)
so the low 2GB is mostly depleted.
Fix this by considering memblock allocations in the initial static
initialization estimation. Move the max_initialise to
reset_deferred_meminit and implement a simple memblock_reserved_memory
helper which iterates all reserved blocks and sums the size of all that
start below the given address. The cumulative size is than added on top
of the initial estimation. This is still not ideal because
reset_deferred_meminit doesn't consider holes and so reservation might
be above the initial estimation whihch we ignore but let's make the
logic simpler until we really need to handle more complicated cases.
Fixes: 3a80a7fa7989 ("mm: meminit: initialise a subset of struct pages if CONFIG_DEFERRED_STRUCT_PAGE_INIT is set")
Link: http://lkml.kernel.org/r/20170531104010.GI27783@dhcp22.suse.cz
Signed-off-by: Michal Hocko <mhocko@suse.com>
Acked-by: Mel Gorman <mgorman@suse.de>
Tested-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit 93407472a21b82f39c955ea7787e5bc7da100642 upstream.
Replace all 1 << inode->i_blkbits and (1 << inode->i_blkbits) in fs
branch.
This patch also fixes multiple checkpatch warnings: WARNING: Prefer
'unsigned int' to bare use of 'unsigned'
Thanks to Andrew Morton for suggesting more appropriate function instead
of macro.
[geliangtang@gmail.com: truncate: use i_blocksize()]
Link: http://lkml.kernel.org/r/9c8b2cd83c8f5653805d43debde9fa8817e02fc4.1484895804.git.geliangtang@gmail.com
Link: http://lkml.kernel.org/r/1481319905-10126-1-git-send-email-fabf@skynet.be
Signed-off-by: Fabian Frederick <fabf@skynet.be>
Signed-off-by: Geliang Tang <geliangtang@gmail.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Ross Zwisler <ross.zwisler@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit 70feee0e1ef331b22cc51f383d532a0d043fbdcc upstream.
Kefeng reported that when running the follow test, the mlock count in
meminfo will increase permanently:
[1] testcase
linux:~ # cat test_mlockal
grep Mlocked /proc/meminfo
for j in `seq 0 10`
do
for i in `seq 4 15`
do
./p_mlockall >> log &
done
sleep 0.2
done
# wait some time to let mlock counter decrease and 5s may not enough
sleep 5
grep Mlocked /proc/meminfo
linux:~ # cat p_mlockall.c
#include <sys/mman.h>
#include <stdlib.h>
#include <stdio.h>
#define SPACE_LEN 4096
int main(int argc, char ** argv)
{
int ret;
void *adr = malloc(SPACE_LEN);
if (!adr)
return -1;
ret = mlockall(MCL_CURRENT | MCL_FUTURE);
printf("mlcokall ret = %d\n", ret);
ret = munlockall();
printf("munlcokall ret = %d\n", ret);
free(adr);
return 0;
}
In __munlock_pagevec() we should decrement NR_MLOCK for each page where
we clear the PageMlocked flag. Commit 1ebb7cc6a583 ("mm: munlock: batch
NR_MLOCK zone state updates") has introduced a bug where we don't
decrement NR_MLOCK for pages where we clear the flag, but fail to
isolate them from the lru list (e.g. when the pages are on some other
cpu's percpu pagevec). Since PageMlocked stays cleared, the NR_MLOCK
accounting gets permanently disrupted by this.
Fix it by counting the number of page whose PageMlock flag is cleared.
Fixes: 1ebb7cc6a583 (" mm: munlock: batch NR_MLOCK zone state updates")
Link: http://lkml.kernel.org/r/1495678405-54569-1-git-send-email-xieyisheng1@huawei.com
Signed-off-by: Yisheng Xie <xieyisheng1@huawei.com>
Reported-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Tested-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Joern Engel <joern@logfs.org>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Michel Lespinasse <walken@google.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Xishi Qiu <qiuxishi@huawei.com>
Cc: zhongjiang <zhongjiang@huawei.com>
Cc: Hanjun Guo <guohanjun@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit 30809f559a0d348c2dfd7ab05e9a451e2384962e upstream.
On failing to migrate a page, soft_offline_huge_page() performs the
necessary update to the hugepage ref-count.
But when !hugepage_migration_supported() , unmap_and_move_hugepage()
also decrements the page ref-count for the hugepage. The combined
behaviour leaves the ref-count in an inconsistent state.
This leads to soft lockups when running the overcommitted hugepage test
from mce-tests suite.
Soft offlining pfn 0x83ed600 at process virtual address 0x400000000000
soft offline: 0x83ed600: migration failed 1, type 1fffc00000008008 (uptodate|head)
INFO: rcu_preempt detected stalls on CPUs/tasks:
Tasks blocked on level-0 rcu_node (CPUs 0-7): P2715
(detected by 7, t=5254 jiffies, g=963, c=962, q=321)
thugetlb_overco R running task 0 2715 2685 0x00000008
Call trace:
dump_backtrace+0x0/0x268
show_stack+0x24/0x30
sched_show_task+0x134/0x180
rcu_print_detail_task_stall_rnp+0x54/0x7c
rcu_check_callbacks+0xa74/0xb08
update_process_times+0x34/0x60
tick_sched_handle.isra.7+0x38/0x70
tick_sched_timer+0x4c/0x98
__hrtimer_run_queues+0xc0/0x300
hrtimer_interrupt+0xac/0x228
arch_timer_handler_phys+0x3c/0x50
handle_percpu_devid_irq+0x8c/0x290
generic_handle_irq+0x34/0x50
__handle_domain_irq+0x68/0xc0
gic_handle_irq+0x5c/0xb0
Address this by changing the putback_active_hugepage() in
soft_offline_huge_page() to putback_movable_pages().
This only triggers on systems that enable memory failure handling
(ARCH_SUPPORTS_MEMORY_FAILURE) but not hugepage migration
(!ARCH_ENABLE_HUGEPAGE_MIGRATION).
I imagine this wasn't triggered as there aren't many systems running
this configuration.
[akpm@linux-foundation.org: remove dead comment, per Naoya]
Link: http://lkml.kernel.org/r/20170525135146.32011-1-punit.agrawal@arm.com
Reported-by: Manoj Iyer <manoj.iyer@canonical.com>
Tested-by: Manoj Iyer <manoj.iyer@canonical.com>
Suggested-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Signed-off-by: Punit Agrawal <punit.agrawal@arm.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Wanpeng Li <wanpeng.li@hotmail.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit 478fe3037b2278d276d4cd9cd0ab06c4cb2e9b32 upstream.
memcg_propagate_slab_attrs() abuses the sysfs attribute file functions
to propagate settings from the root kmem_cache to a newly created
kmem_cache. It does that with:
attr->show(root, buf);
attr->store(new, buf, strlen(bug);
Aside of being a lazy and absurd hackery this is broken because it does
not check the return value of the show() function.
Some of the show() functions return 0 w/o touching the buffer. That
means in such a case the store function is called with the stale content
of the previous show(). That causes nonsense like invoking
kmem_cache_shrink() on a newly created kmem_cache. In the worst case it
would cause handing in an uninitialized buffer.
This should be rewritten proper by adding a propagate() callback to
those slub_attributes which must be propagated and avoid that insane
conversion to and from ASCII, but that's too large for a hot fix.
Check at least the return value of the show() function, so calling
store() with stale content is prevented.
Steven said:
"It can cause a deadlock with get_online_cpus() that has been uncovered
by recent cpu hotplug and lockdep changes that Thomas and Peter have
been doing.
Possible unsafe locking scenario:
CPU0 CPU1
---- ----
lock(cpu_hotplug.lock);
lock(slab_mutex);
lock(cpu_hotplug.lock);
lock(slab_mutex);
*** DEADLOCK ***"
Link: http://lkml.kernel.org/r/alpine.DEB.2.20.1705201244540.2255@nanos
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reported-by: Steven Rostedt <rostedt@goodmis.org>
Acked-by: David Rientjes <rientjes@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit 8310d48b125d19fcd9521d83b8293e63eb1646aa upstream.
In commit 19be0eaffa3a ("mm: remove gup_flags FOLL_WRITE games from
__get_user_pages()"), the mm code was changed from unsetting FOLL_WRITE
after a COW was resolved to setting the (newly introduced) FOLL_COW
instead. Simultaneously, the check in gup.c was updated to still allow
writes with FOLL_FORCE set if FOLL_COW had also been set.
However, a similar check in huge_memory.c was forgotten. As a result,
remote memory writes to ro regions of memory backed by transparent huge
pages cause an infinite loop in the kernel (handle_mm_fault sets
FOLL_COW and returns 0 causing a retry, but follow_trans_huge_pmd bails
out immidiately because `(flags & FOLL_WRITE) && !pmd_write(*pmd)` is
true.
While in this state the process is stil SIGKILLable, but little else
works (e.g. no ptrace attach, no other signals). This is easily
reproduced with the following code (assuming thp are set to always):
#include <assert.h>
#include <fcntl.h>
#include <stdint.h>
#include <stdio.h>
#include <string.h>
#include <sys/mman.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <unistd.h>
#define TEST_SIZE 5 * 1024 * 1024
int main(void) {
int status;
pid_t child;
int fd = open("/proc/self/mem", O_RDWR);
void *addr = mmap(NULL, TEST_SIZE, PROT_READ,
MAP_ANONYMOUS | MAP_PRIVATE, 0, 0);
assert(addr != MAP_FAILED);
pid_t parent_pid = getpid();
if ((child = fork()) == 0) {
void *addr2 = mmap(NULL, TEST_SIZE, PROT_READ | PROT_WRITE,
MAP_ANONYMOUS | MAP_PRIVATE, 0, 0);
assert(addr2 != MAP_FAILED);
memset(addr2, 'a', TEST_SIZE);
pwrite(fd, addr2, TEST_SIZE, (uintptr_t)addr);
return 0;
}
assert(child == waitpid(child, &status, 0));
assert(WIFEXITED(status) && WEXITSTATUS(status) == 0);
return 0;
}
Fix this by updating follow_trans_huge_pmd in huge_memory.c analogously
to the update in gup.c in the original commit. The same pattern exists
in follow_devmap_pmd. However, we should not be able to reach that
check with FOLL_COW set, so add WARN_ONCE to make sure we notice if we
ever do.
[akpm@linux-foundation.org: coding-style fixes]
Link: http://lkml.kernel.org/r/20170106015025.GA38411@juliacomputing.com
Signed-off-by: Keno Fischer <keno@juliacomputing.com>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Greg Thelen <gthelen@google.com>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Willy Tarreau <w@1wt.eu>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Hugh Dickins <hughd@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>
[AmitP: Minor refactoring of upstream changes for linux-3.18.y,
where follow_devmap_pmd() doesn't exist.]
Signed-off-by: Amit Pundir <amit.pundir@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit cf01fb9985e8deb25ccf0ea54d916b8871ae0e62 upstream.
In the case that compat_get_bitmap fails we do not want to copy the
bitmap to the user as it will contain uninitialized stack data and leak
sensitive data.
Signed-off-by: Chris Salls <salls@cs.ucsb.edu>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit c9d398fa237882ea07167e23bcfc5e6847066518 upstream.
I found the race condition which triggers the following bug when
move_pages() and soft offline are called on a single hugetlb page
concurrently.
Soft offlining page 0x119400 at 0x700000000000
BUG: unable to handle kernel paging request at ffffea0011943820
IP: follow_huge_pmd+0x143/0x190
PGD 7ffd2067
PUD 7ffd1067
PMD 0
[61163.582052] Oops: 0000 [#1] SMP
Modules linked in: binfmt_misc ppdev virtio_balloon parport_pc pcspkr i2c_piix4 parport i2c_core acpi_cpufreq ip_tables xfs libcrc32c ata_generic pata_acpi virtio_blk 8139too crc32c_intel ata_piix serio_raw libata virtio_pci 8139cp virtio_ring virtio mii floppy dm_mirror dm_region_hash dm_log dm_mod [last unloaded: cap_check]
CPU: 0 PID: 22573 Comm: iterate_numa_mo Tainted: P OE 4.11.0-rc2-mm1+ #2
Hardware name: Red Hat KVM, BIOS 0.5.1 01/01/2011
RIP: 0010:follow_huge_pmd+0x143/0x190
RSP: 0018:ffffc90004bdbcd0 EFLAGS: 00010202
RAX: 0000000465003e80 RBX: ffffea0004e34d30 RCX: 00003ffffffff000
RDX: 0000000011943800 RSI: 0000000000080001 RDI: 0000000465003e80
RBP: ffffc90004bdbd18 R08: 0000000000000000 R09: ffff880138d34000
R10: ffffea0004650000 R11: 0000000000c363b0 R12: ffffea0011943800
R13: ffff8801b8d34000 R14: ffffea0000000000 R15: 000077ff80000000
FS: 00007fc977710740(0000) GS:ffff88007dc00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffea0011943820 CR3: 000000007a746000 CR4: 00000000001406f0
Call Trace:
follow_page_mask+0x270/0x550
SYSC_move_pages+0x4ea/0x8f0
SyS_move_pages+0xe/0x10
do_syscall_64+0x67/0x180
entry_SYSCALL64_slow_path+0x25/0x25
RIP: 0033:0x7fc976e03949
RSP: 002b:00007ffe72221d88 EFLAGS: 00000246 ORIG_RAX: 0000000000000117
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fc976e03949
RDX: 0000000000c22390 RSI: 0000000000001400 RDI: 0000000000005827
RBP: 00007ffe72221e00 R08: 0000000000c2c3a0 R09: 0000000000000004
R10: 0000000000c363b0 R11: 0000000000000246 R12: 0000000000400650
R13: 00007ffe72221ee0 R14: 0000000000000000 R15: 0000000000000000
Code: 81 e4 ff ff 1f 00 48 21 c2 49 c1 ec 0c 48 c1 ea 0c 4c 01 e2 49 bc 00 00 00 00 00 ea ff ff 48 c1 e2 06 49 01 d4 f6 45 bc 04 74 90 <49> 8b 7c 24 20 40 f6 c7 01 75 2b 4c 89 e7 8b 47 1c 85 c0 7e 2a
RIP: follow_huge_pmd+0x143/0x190 RSP: ffffc90004bdbcd0
CR2: ffffea0011943820
---[ end trace e4f81353a2d23232 ]---
Kernel panic - not syncing: Fatal exception
Kernel Offset: disabled
This bug is triggered when pmd_present() returns true for non-present
hugetlb, so fixing the present check in follow_huge_pmd() prevents it.
Using pmd_present() to determine present/non-present for hugetlb is not
correct, because pmd_present() checks multiple bits (not only
_PAGE_PRESENT) for historical reason and it can misjudge hugetlb state.
Fixes: e66f17ff7177 ("mm/hugetlb: take page table lock in follow_huge_pmd()")
Link: http://lkml.kernel.org/r/1490149898-20231-1-git-send-email-n-horiguchi@ah.jp.nec.com
Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Acked-by: Hillf Danton <hillf.zj@alibaba-inc.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit 320661b08dd6f1746d5c7ab4eb435ec64b97cd45 upstream.
Update to pcpu_nr_empty_pop_pages in pcpu_alloc() is currently done
without holding pcpu_lock. This can lead to bad updates to the variable.
Add missing lock calls.
Fixes: b539b87fed37 ("percpu: implmeent pcpu_nr_empty_pop_pages and chunk->nr_populated")
Signed-off-by: Tahsin Erdogan <tahsin@google.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit 358c07fcc3b60ab08d77f1684de8bd81bcf49a1a upstream.
A bugfix in v4.8-rc2 introduced a harmless warning when
CONFIG_MEMCG_SWAP is disabled but CONFIG_MEMCG is enabled:
mm/memcontrol.c:4085:27: error: 'mem_cgroup_id_get_online' defined but not used [-Werror=unused-function]
static struct mem_cgroup *mem_cgroup_id_get_online(struct mem_cgroup *memcg)
This moves the function inside of the #ifdef block that hides the
calling function, to avoid the warning.
Fixes: 1f47b61fb407 ("mm: memcontrol: fix swap counter leak on swapout from offline cgroup")
Link: http://lkml.kernel.org/r/20160824113733.2776701-1-arnd@arndb.de
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Vladimir Davydov <vdavydov@virtuozzo.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit dd8416c47715cf324c9a16f13273f9fda87acfed upstream.
With rw_page, page_endio is used for completing IO on a page and it
propagates write error to the address space if the IO fails. The
problem is it accesses page->mapping directly which might be okay for
file-backed pages but it shouldn't for anonymous page. Otherwise, it
can corrupt one of field from anon_vma under us and system goes panic
randomly.
swap_writepage
bdev_writepage
ops->rw_page
I encountered the BUG during developing new zram feature and it was
really hard to figure it out because it made random crash, somtime
mmap_sem lockdep, sometime other places where places never related to
zram/zsmalloc, and not reproducible with some configuration.
When I consider how that bug is subtle and people do fast-swap test with
brd, it's worth to add stable mark, I think.
Fixes: dd6bd0d9c7db ("swap: use bdev_read_page() / bdev_write_page()")
Signed-off-by: Minchan Kim <minchan@kernel.org>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Matthew Wilcox <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit e1587a4945408faa58d0485002c110eb2454740c upstream.
At the end of a window period, if the reclaimed pages is greater than
scanned, an unsigned underflow can result in a huge pressure value and
thus a critical event. Reclaimed pages is found to go higher than
scanned because of the addition of reclaimed slab pages to reclaimed in
shrink_node without a corresponding increment to scanned pages.
Minchan Kim mentioned that this can also happen in the case of a THP
page where the scanned is 1 and reclaimed could be 512.
Link: http://lkml.kernel.org/r/1486641577-11685-1-git-send-email-vinmenon@codeaurora.org
Signed-off-by: Vinayak Menon <vinmenon@codeaurora.org>
Acked-by: Minchan Kim <minchan@kernel.org>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Rik van Riel <riel@redhat.com>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: Anton Vorontsov <anton.vorontsov@linaro.org>
Cc: Shiraz Hashim <shashim@codeaurora.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit e02dc017c3032dcdce1b993af0db135462e1b4b7 upstream.
When @node_reclaim_node isn't 0, the page allocator tries to reclaim
pages if the amount of free memory in the zones are below the low
watermark. On Power platform, none of NUMA nodes are scanned for page
reclaim because no nodes match the condition in zone_allows_reclaim().
On Power platform, RECLAIM_DISTANCE is set to 10 which is the distance
of Node-A to Node-A. So the preferred node even won't be scanned for
page reclaim.
__alloc_pages_nodemask()
get_page_from_freelist()
zone_allows_reclaim()
Anton proposed the test code as below:
# cat alloc.c
:
int main(int argc, char *argv[])
{
void *p;
unsigned long size;
unsigned long start, end;
start = time(NULL);
size = strtoul(argv[1], NULL, 0);
printf("To allocate %ldGB memory\n", size);
size <<= 30;
p = malloc(size);
assert(p);
memset(p, 0, size);
end = time(NULL);
printf("Used time: %ld seconds\n", end - start);
sleep(3600);
return 0;
}
The system I use for testing has two NUMA nodes. Both have 128GB
memory. In below scnario, the page caches on node#0 should be reclaimed
when it encounters pressure to accommodate request of allocation.
# echo 2 > /proc/sys/vm/zone_reclaim_mode; \
sync; \
echo 3 > /proc/sys/vm/drop_caches; \
# taskset -c 0 cat file.32G > /dev/null; \
grep FilePages /sys/devices/system/node/node0/meminfo
Node 0 FilePages: 33619712 kB
# taskset -c 0 ./alloc 128
# grep FilePages /sys/devices/system/node/node0/meminfo
Node 0 FilePages: 33619840 kB
# grep MemFree /sys/devices/system/node/node0/meminfo
Node 0 MemFree: 186816 kB
With the patch applied, the pagecache on node-0 is reclaimed when its
free memory is running out. It's the expected behaviour.
# echo 2 > /proc/sys/vm/zone_reclaim_mode; \
sync; \
echo 3 > /proc/sys/vm/drop_caches
# taskset -c 0 cat file.32G > /dev/null; \
grep FilePages /sys/devices/system/node/node0/meminfo
Node 0 FilePages: 33605568 kB
# taskset -c 0 ./alloc 128
# grep FilePages /sys/devices/system/node/node0/meminfo
Node 0 FilePages: 1379520 kB
# grep MemFree /sys/devices/system/node/node0/meminfo
Node 0 MemFree: 317120 kB
Fixes: 5f7a75acdb24 ("mm: page_alloc: do not cache reclaim distances")
Link: http://lkml.kernel.org/r/1486532455-29613-1-git-send-email-gwshan@linux.vnet.ibm.com
Signed-off-by: Gavin Shan <gwshan@linux.vnet.ibm.com>
Acked-by: Mel Gorman <mgorman@suse.de>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Anton Blanchard <anton@samba.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit 5f478e4ea5c5560b4e40eb136991a09f9389f331 upstream.
When !CONFIG_CGROUP_WRITEBACK, bdi has single bdi_writeback_congested
at bdi->wb_congested. cgwb_bdi_init() allocates it with kzalloc() and
doesn't do further initialization. This usually works fine as the
reference count gets bumped to 1 by wb_init() and the put from
wb_exit() releases it.
However, when wb_init() fails, it puts the wb base ref automatically
freeing the wb and the explicit kfree() in cgwb_bdi_init() error path
ends up trying to free the same pointer the second time causing a
double-free.
Fix it by explicitly initilizing the refcnt to 1 and putting the base
ref from cgwb_bdi_destroy().
Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-by: Dmitry Vyukov <dvyukov@google.com>
Fixes: a13f35e87140 ("writeback: don't embed root bdi_writeback_congested in bdi_writeback")
Signed-off-by: Jens Axboe <axboe@fb.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit a96dfddbcc04336bbed50dc2b24823e45e09e80c upstream.
Reading a sysfs "memoryN/valid_zones" file leads to the following oops
when the first page of a range is not backed by struct page.
show_valid_zones() assumes that 'start_pfn' is always valid for
page_zone().
BUG: unable to handle kernel paging request at ffffea017a000000
IP: show_valid_zones+0x6f/0x160
This issue may happen on x86-64 systems with 64GiB or more memory since
their memory block size is bumped up to 2GiB. [1] An example of such
systems is desribed below. 0x3240000000 is only aligned by 1GiB and
this memory block starts from 0x3200000000, which is not backed by
struct page.
BIOS-e820: [mem 0x0000003240000000-0x000000603fffffff] usable
Since test_pages_in_a_zone() already checks holes, fix this issue by
extending this function to return 'valid_start' and 'valid_end' for a
given range. show_valid_zones() then proceeds with the valid range.
[1] 'Commit bdee237c0343 ("x86: mm: Use 2GB memory block size on
large-memory x86-64 systems")'
Link: http://lkml.kernel.org/r/20170127222149.30893-3-toshi.kani@hpe.com
Signed-off-by: Toshi Kani <toshi.kani@hpe.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Zhang Zhen <zhenzhang.zhang@huawei.com>
Cc: Reza Arbab <arbab@linux.vnet.ibm.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: <stable@vger.kernel.org> [4.4+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit 5abf186a30a89d5b9c18a6bf93a2c192c9fd52f6 upstream.
do_generic_file_read() can be told to perform a large request from
userspace. If the system is under OOM and the reading task is the OOM
victim then it has an access to memory reserves and finishing the full
request can lead to the full memory depletion which is dangerous. Make
sure we rather go with a short read and allow the killed task to
terminate.
Link: http://lkml.kernel.org/r/20170201092706.9966-3-mhocko@kernel.org
Signed-off-by: Michal Hocko <mhocko@suse.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit deb88a2a19e85842d79ba96b05031739ec327ff4 upstream.
Patch series "fix a kernel oops when reading sysfs valid_zones", v2.
A sysfs memory file is created for each 2GiB memory block on x86-64 when
the system has 64GiB or more memory. [1] When the start address of a
memory block is not backed by struct page, i.e. a memory range is not
aligned by 2GiB, reading its 'valid_zones' attribute file leads to a
kernel oops. This issue was observed on multiple x86-64 systems with
more than 64GiB of memory. This patch-set fixes this issue.
Patch 1 first fixes an issue in test_pages_in_a_zone(), which does not
test the start section.
Patch 2 then fixes the kernel oops by extending test_pages_in_a_zone()
to return valid [start, end).
Note for stable kernels: The memory block size change was made by commit
bdee237c0343 ("x86: mm: Use 2GB memory block size on large-memory x86-64
systems"), which was accepted to 3.9. However, this patch-set depends
on (and fixes) the change to test_pages_in_a_zone() made by commit
5f0f2887f4de ("mm/memory_hotplug.c: check for missing sections in
test_pages_in_a_zone()"), which was accepted to 4.4.
So, I recommend that we backport it up to 4.4.
[1] 'Commit bdee237c0343 ("x86: mm: Use 2GB memory block size on
large-memory x86-64 systems")'
This patch (of 2):
test_pages_in_a_zone() does not check 'start_pfn' when it is aligned by
section since 'sec_end_pfn' is set equal to 'pfn'. Since this function
is called for testing the range of a sysfs memory file, 'start_pfn' is
always aligned by section.
Fix it by properly setting 'sec_end_pfn' to the next section pfn.
Also make sure that this function returns 1 only when the range belongs
to a zone.
Link: http://lkml.kernel.org/r/20170127222149.30893-2-toshi.kani@hpe.com
Signed-off-by: Toshi Kani <toshi.kani@hpe.com>
Cc: Andrew Banman <abanman@sgi.com>
Cc: Reza Arbab <arbab@linux.vnet.ibm.com>
Cc: Greg KH <greg@kroah.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit d7b028f56a971a2e4d8d7887540a144eeefcd4ab upstream.
Add zswap_init_failed bool that prevents changing any of the module
params, if init_zswap() fails, and set zswap_enabled to false. Change
'enabled' param to a callback, and check zswap_init_failed before
allowing any change to 'enabled', 'zpool', or 'compressor' params.
Any driver that is built-in to the kernel will not be unloaded if its
init function returns error, and its module params remain accessible for
users to change via sysfs. Since zswap uses param callbacks, which
assume that zswap has been initialized, changing the zswap params after
a failed initialization will result in WARNING due to the param
callbacks expecting a pool to already exist. This prevents that by
immediately exiting any of the param callbacks if initialization failed.
This was reported here:
https://marc.info/?l=linux-mm&m=147004228125528&w=4
And fixes this WARNING:
[ 429.723476] WARNING: CPU: 0 PID: 5140 at mm/zswap.c:503 __zswap_pool_current+0x56/0x60
The warning is just noise, and not serious. However, when init fails,
zswap frees all its percpu dstmem pages and its kmem cache. The kmem
cache might be serious, if kmem_cache_alloc(NULL, gfp) has problems; but
the percpu dstmem pages are definitely a problem, as they're used as
temporary buffer for compressed pages before copying into place in the
zpool.
If the user does get zswap enabled after an init failure, then zswap
will likely Oops on the first page it tries to compress (or worse, start
corrupting memory).
Fixes: 90b0fc26d5db ("zswap: change zpool/compressor at runtime")
Link: http://lkml.kernel.org/r/20170124200259.16191-2-ddstreet@ieee.org
Signed-off-by: Dan Streetman <dan.streetman@canonical.com>
Reported-by: Marcin Miroslaw <marcin@mejor.pl>
Cc: Seth Jennings <sjenning@redhat.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>
Cc: Minchan Kim <minchan@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit 3674534b775354516e5c148ea48f51d4d1909a78 upstream.
When memory.move_charge_at_immigrate is enabled and precharges are
depleted during move, mem_cgroup_move_charge_pte_range() will attempt to
increase the size of the precharge.
Prevent precharges from ever looping by setting __GFP_NORETRY. This was
probably the intention of the GFP_KERNEL & ~__GFP_NORETRY, which is
pointless as written.
Fixes: 0029e19ebf84 ("mm: memcontrol: remove explicit OOM parameter in charge path")
Link: http://lkml.kernel.org/r/alpine.DEB.2.10.1701130208510.69402@chino.kir.corp.google.com
Signed-off-by: David Rientjes <rientjes@google.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit d51e9894d27492783fc6d1b489070b4ba66ce969 upstream.
Since commit be97a41b291e ("mm/mempolicy.c: merge alloc_hugepage_vma to
alloc_pages_vma") alloc_pages_vma() can potentially free a mempolicy by
mpol_cond_put() before accessing the embedded nodemask by
__alloc_pages_nodemask(). The commit log says it's so "we can use a
single exit path within the function" but that's clearly wrong. We can
still do that when doing mpol_cond_put() after the allocation attempt.
Make sure the mempolicy is not freed prematurely, otherwise
__alloc_pages_nodemask() can end up using a bogus nodemask, which could
lead e.g. to premature OOM.
Fixes: be97a41b291e ("mm/mempolicy.c: merge alloc_hugepage_vma to alloc_pages_vma")
Link: http://lkml.kernel.org/r/20170118141124.8345-1-vbabka@suse.cz
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: David Rientjes <rientjes@google.com>
Cc: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit e5bbc8a6c992901058bc09e2ce01d16c111ff047 upstream.
return_unused_surplus_pages() decrements the global reservation count,
and frees any unused surplus pages that were backing the reservation.
Commit 7848a4bf51b3 ("mm/hugetlb.c: add cond_resched_lock() in
return_unused_surplus_pages()") added a call to cond_resched_lock in the
loop freeing the pages.
As a result, the hugetlb_lock could be dropped, and someone else could
use the pages that will be freed in subsequent iterations of the loop.
This could result in inconsistent global hugetlb page state, application
api failures (such as mmap) failures or application crashes.
When dropping the lock in return_unused_surplus_pages, make sure that
the global reservation count (resv_huge_pages) remains sufficiently
large to prevent someone else from claiming pages about to be freed.
Analyzed by Paul Cassella.
Fixes: 7848a4bf51b3 ("mm/hugetlb.c: add cond_resched_lock() in return_unused_surplus_pages()")
Link: http://lkml.kernel.org/r/1483991767-6879-1-git-send-email-mike.kravetz@oracle.com
Signed-off-by: Mike Kravetz <mike.kravetz@oracle.com>
Reported-by: Paul Cassella <cassella@cray.com>
Suggested-by: Michal Hocko <mhocko@kernel.org>
Cc: Masayoshi Mizuma <m.mizuma@jp.fujitsu.com>
Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: Aneesh Kumar <aneesh.kumar@linux.vnet.ibm.com>
Cc: Hillf Danton <hillf.zj@alibaba-inc.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit 90cae1fe1c3540f791d5b8e025985fa5e699b2bb upstream.
As a part of memory initialisation the architecture passes an array to
free_area_init_nodes() which specifies the max PFN of each memory zone.
This array is not necessarily monotonic (due to unused zones) so this
array is parsed to build monotonic lists of the min and max PFN for each
zone. ZONE_MOVABLE is special cased here as its limits are managed by
the mm subsystem rather than the architecture. Unfortunately, this
special casing is broken when ZONE_MOVABLE is the not the last zone in
the zone list. The core of the issue is:
if (i == ZONE_MOVABLE)
continue;
arch_zone_lowest_possible_pfn[i] =
arch_zone_highest_possible_pfn[i-1];
As ZONE_MOVABLE is skipped the lowest_possible_pfn of the next zone will
be set to zero. This patch fixes this bug by adding explicitly tracking
where the next zone should start rather than relying on the contents
arch_zone_highest_possible_pfn[].
Thie is low priority. To get bitten by this you need to enable a zone
that appears after ZONE_MOVABLE in the zone_type enum. As far as I can
tell this means running a kernel with ZONE_DEVICE or ZONE_CMA enabled,
so I can't see this affecting too many people.
I only noticed this because I've been fiddling with ZONE_DEVICE on
powerpc and 4.6 broke my test kernel. This bug, in conjunction with the
changes in Taku Izumi's kernelcore=mirror patch (d91749c1dda71) and
powerpc being the odd architecture which initialises max_zone_pfn[] to
~0ul instead of 0 caused all of system memory to be placed into
ZONE_DEVICE at boot, followed a panic since device memory cannot be used
for kernel allocations. I've already submitted a patch to fix the
powerpc specific bits, but I figured this should be fixed too.
Link: http://lkml.kernel.org/r/1462435033-15601-1-git-send-email-oohall@gmail.com
Signed-off-by: Oliver O'Halloran <oohall@gmail.com>
Cc: Anton Blanchard <anton@samba.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit 5f33a0803bbd781de916f5c7448cbbbbc763d911 upstream.
Our system uses significantly more slab memory with memcg enabled with
the latest kernel. With 3.10 kernel, slab uses 2G memory, while with
4.6 kernel, 6G memory is used. The shrinker has problem. Let's see we
have two memcg for one shrinker. In do_shrink_slab:
1. Check cg1. nr_deferred = 0, assume total_scan = 700. batch size
is 1024, then no memory is freed. nr_deferred = 700
2. Check cg2. nr_deferred = 700. Assume freeable = 20, then
total_scan = 10 or 40. Let's assume it's 10. No memory is freed.
nr_deferred = 10.
The deferred share of cg1 is lost in this case. kswapd will free no
memory even run above steps again and again.
The fix makes sure one memcg's deferred share isn't lost.
Link: http://lkml.kernel.org/r/2414be961b5d25892060315fbb56bb19d81d0c07.1476227351.git.shli@fb.com
Signed-off-by: Shaohua Li <shli@fb.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Vladimir Davydov <vdavydov@parallels.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit bfedb589252c01fa505ac9f6f2a3d5d68d707ef4 upstream.
During exec dumpable is cleared if the file that is being executed is
not readable by the user executing the file. A bug in
ptrace_may_access allows reading the file if the executable happens to
enter into a subordinate user namespace (aka clone(CLONE_NEWUSER),
unshare(CLONE_NEWUSER), or setns(fd, CLONE_NEWUSER).
This problem is fixed with only necessary userspace breakage by adding
a user namespace owner to mm_struct, captured at the time of exec, so
it is clear in which user namespace CAP_SYS_PTRACE must be present in
to be able to safely give read permission to the executable.
The function ptrace_may_access is modified to verify that the ptracer
has CAP_SYS_ADMIN in task->mm->user_ns instead of task->cred->user_ns.
This ensures that if the task changes it's cred into a subordinate
user namespace it does not become ptraceable.
The function ptrace_attach is modified to only set PT_PTRACE_CAP when
CAP_SYS_PTRACE is held over task->mm->user_ns. The intent of
PT_PTRACE_CAP is to be a flag to note that whatever permission changes
the task might go through the tracer has sufficient permissions for
it not to be an issue. task->cred->user_ns is always the same
as or descendent of mm->user_ns. Which guarantees that having
CAP_SYS_PTRACE over mm->user_ns is the worst case for the tasks
credentials.
To prevent regressions mm->dumpable and mm->user_ns are not considered
when a task has no mm. As simply failing ptrace_may_attach causes
regressions in privileged applications attempting to read things
such as /proc/<pid>/stat
Acked-by: Kees Cook <keescook@chromium.org>
Tested-by: Cyrill Gorcunov <gorcunov@openvz.org>
Fixes: 8409cca70561 ("userns: allow ptrace from non-init user namespaces")
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit 045d599a286bc01daa3510d59272440a17b23c2e upstream.
kasan_global struct is part of compiler/runtime ABI. gcc revision
241983 has added a new field to kasan_global struct. Update kernel
definition of kasan_global struct to include the new field.
Without this patch KASAN is broken with gcc 7.
Link: http://lkml.kernel.org/r/1479219743-28682-1-git-send-email-dvyukov@google.com
Signed-off-by: Dmitry Vyukov <dvyukov@google.com>
Acked-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Alexander Potapenko <glider@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit dd111be69114cc867f8e826284559bfbc1c40e37 upstream.
When root activates a swap partition whose header has the wrong
endianness, nr_badpages elements of badpages are swabbed before
nr_badpages has been checked, leading to a buffer overrun of up to 8GB.
This normally is not a security issue because it can only be exploited
by root (more specifically, a process with CAP_SYS_ADMIN or the ability
to modify a swap file/partition), and such a process can already e.g.
modify swapped-out memory of any other userspace process on the system.
Link: http://lkml.kernel.org/r/1477949533-2509-1-git-send-email-jann@thejh.net
Signed-off-by: Jann Horn <jann@thejh.net>
Acked-by: Kees Cook <keescook@chromium.org>
Acked-by: Jerome Marchand <jmarchan@redhat.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit badbda53e505089062e194c614e6f23450bc98b2 upstream.
pageblock_order can be (at least) an unsigned int or an unsigned long
depending on the kernel config and architecture, so use max_t(unsigned
long, ...) when comparing it.
fixes these warnings:
In file included from include/asm-generic/bug.h:13:0,
from arch/powerpc/include/asm/bug.h:127,
from include/linux/bug.h:4,
from include/linux/mmdebug.h:4,
from include/linux/mm.h:8,
from include/linux/memblock.h:18,
from mm/cma.c:28:
mm/cma.c: In function 'cma_init_reserved_mem':
include/linux/kernel.h:748:17: warning: comparison of distinct pointer types lacks a cast
(void) (&_max1 == &_max2); ^
mm/cma.c:186:27: note: in expansion of macro 'max'
alignment = PAGE_SIZE << max(MAX_ORDER - 1, pageblock_order);
^
mm/cma.c: In function 'cma_declare_contiguous':
include/linux/kernel.h:748:17: warning: comparison of distinct pointer types lacks a cast
(void) (&_max1 == &_max2); ^
include/linux/kernel.h:747:9: note: in definition of macro 'max'
typeof(y) _max2 = (y); ^
mm/cma.c:270:29: note: in expansion of macro 'max'
(phys_addr_t)PAGE_SIZE << max(MAX_ORDER - 1, pageblock_order));
^
include/linux/kernel.h:748:17: warning: comparison of distinct pointer types lacks a cast
(void) (&_max1 == &_max2); ^
include/linux/kernel.h:747:21: note: in definition of macro 'max'
typeof(y) _max2 = (y); ^
mm/cma.c:270:29: note: in expansion of macro 'max'
(phys_addr_t)PAGE_SIZE << max(MAX_ORDER - 1, pageblock_order));
^
[akpm@linux-foundation.org: coding-style fixes]
Link: http://lkml.kernel.org/r/20160526150748.5be38a4f@canb.auug.org.au
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit 89a2848381b5fcd9c4d9c0cd97680e3b28730e31 upstream.
On 4.0, we saw a stack corruption from a page fault entering direct
memory cgroup reclaim, calling into btrfs_releasepage(), which then
tried to allocate an extent and recursed back into a kmem charge ad
nauseam:
[...]
btrfs_releasepage+0x2c/0x30
try_to_release_page+0x32/0x50
shrink_page_list+0x6da/0x7a0
shrink_inactive_list+0x1e5/0x510
shrink_lruvec+0x605/0x7f0
shrink_zone+0xee/0x320
do_try_to_free_pages+0x174/0x440
try_to_free_mem_cgroup_pages+0xa7/0x130
try_charge+0x17b/0x830
memcg_charge_kmem+0x40/0x80
new_slab+0x2d9/0x5a0
__slab_alloc+0x2fd/0x44f
kmem_cache_alloc+0x193/0x1e0
alloc_extent_state+0x21/0xc0
__clear_extent_bit+0x2b5/0x400
try_release_extent_mapping+0x1a3/0x220
__btrfs_releasepage+0x31/0x70
btrfs_releasepage+0x2c/0x30
try_to_release_page+0x32/0x50
shrink_page_list+0x6da/0x7a0
shrink_inactive_list+0x1e5/0x510
shrink_lruvec+0x605/0x7f0
shrink_zone+0xee/0x320
do_try_to_free_pages+0x174/0x440
try_to_free_mem_cgroup_pages+0xa7/0x130
try_charge+0x17b/0x830
mem_cgroup_try_charge+0x65/0x1c0
handle_mm_fault+0x117f/0x1510
__do_page_fault+0x177/0x420
do_page_fault+0xc/0x10
page_fault+0x22/0x30
On later kernels, kmem charging is opt-in rather than opt-out, and that
particular kmem allocation in btrfs_releasepage() is no longer being
charged and won't recurse and overrun the stack anymore.
But it's not impossible for an accounted allocation to happen from the
memcg direct reclaim context, and we needed to reproduce this crash many
times before we even got a useful stack trace out of it.
Like other direct reclaimers, mark tasks in memcg reclaim PF_MEMALLOC to
avoid recursing into any other form of direct reclaim. Then let
recursive charges from PF_MEMALLOC contexts bypass the cgroup limit.
Link: http://lkml.kernel.org/r/20161025141050.GA13019@cmpxchg.org
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit 1bc11d70b5db7c6bb1414b283d7f09b1fe1ac0d0 upstream.
As described in https://bugzilla.kernel.org/show_bug.cgi?id=177821:
After some analysis it seems to be that the problem is in alloc_super().
In case list_lru_init_memcg() fails it goes into destroy_super(), which
calls list_lru_destroy().
And in list_lru_init() we see that in case memcg_init_list_lru() fails,
lru->node is freed, but not set NULL, which then leads list_lru_destroy()
to believe it is initialized and call memcg_destroy_list_lru().
memcg_destroy_list_lru() in turn can access lru->node[i].memcg_lrus,
which is NULL.
[akpm@linux-foundation.org: add comment]
Signed-off-by: Alexander Polakov <apolyakov@beget.ru>
Acked-by: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit 2247bb335ab9c40058484cac36ea74ee652f3b7b upstream.
Patch series "mm/hugetlb: memory offline issues with hugepages", v4.
This addresses several issues with hugepages and memory offline. While
the first patch fixes a panic, and is therefore rather important, the
last patch is just a performance optimization.
The second patch fixes a theoretical issue with reserved hugepages,
while still leaving some ugly usability issue, see description.
This patch (of 3):
dissolve_free_huge_pages() will either run into the VM_BUG_ON() or a
list corruption and addressing exception when trying to set a memory
block offline that is part (but not the first part) of a "gigantic"
hugetlb page with a size > memory block size.
When no other smaller hugetlb page sizes are present, the VM_BUG_ON()
will trigger directly. In the other case we will run into an addressing
exception later, because dissolve_free_huge_page() will not work on the
head page of the compound hugetlb page which will result in a NULL
hstate from page_hstate().
To fix this, first remove the VM_BUG_ON() because it is wrong, and then
use the compound head page in dissolve_free_huge_page(). This means
that an unused pre-allocated gigantic page that has any part of itself
inside the memory block that is going offline will be dissolved
completely. Losing an unused gigantic hugepage is preferable to failing
the memory offline, for example in the situation where a (possibly
faulty) memory DIMM needs to go offline.
Changes for v4.4 stable:
- make it apply w/o commit c1470b33 "mm/hugetlb: fix incorrect
hugepages count during mem hotplug"
Fixes: c8721bbb ("mm: memory-hotplug: enable memory hotplug to handle hugepage")
Link: http://lkml.kernel.org/r/20160926172811.94033-2-gerald.schaefer@de.ibm.com
Signed-off-by: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: "Kirill A . Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: "Aneesh Kumar K . V" <aneesh.kumar@linux.vnet.ibm.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Rui Teng <rui.teng@linux.vnet.ibm.com>
Cc: Dave Hansen <dave.hansen@linux.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>
Signed-off-by: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit 3ddf40e8c31964b744ff10abb48c8e36a83ec6e7 upstream.
Commit 22f2ac51b6d6 ("mm: workingset: fix crash in shadow node shrinker
caused by replace_page_cache_page()") switched replace_page_cache() from
raw radix tree operations to page_cache_tree_insert() but didn't take
into account that the latter function, unlike the raw radix tree op,
handles mapping->nrpages. As a result, that counter is bumped for each
page replacement rather than balanced out even.
The mapping->nrpages counter is used to skip needless radix tree walks
when invalidating, truncating, syncing inodes without pages, as well as
statistics for userspace. Since the error is positive, we'll do more
page cache tree walks than necessary; we won't miss a necessary one.
And we'll report more buffer pages to userspace than there are. The
error is limited to fuse inodes.
Fixes: 22f2ac51b6d6 ("mm: workingset: fix crash in shadow node shrinker caused by replace_page_cache_page()")
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Miklos Szeredi <miklos@szeredi.hu>
Cc: stable@vger.kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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replace_page_cache_page()
commit 22f2ac51b6d643666f4db093f13144f773ff3f3a upstream.
Antonio reports the following crash when using fuse under memory pressure:
kernel BUG at /build/linux-a2WvEb/linux-4.4.0/mm/workingset.c:346!
invalid opcode: 0000 [#1] SMP
Modules linked in: all of them
CPU: 2 PID: 63 Comm: kswapd0 Not tainted 4.4.0-36-generic #55-Ubuntu
Hardware name: System manufacturer System Product Name/P8H67-M PRO, BIOS 3904 04/27/2013
task: ffff88040cae6040 ti: ffff880407488000 task.ti: ffff880407488000
RIP: shadow_lru_isolate+0x181/0x190
Call Trace:
__list_lru_walk_one.isra.3+0x8f/0x130
list_lru_walk_one+0x23/0x30
scan_shadow_nodes+0x34/0x50
shrink_slab.part.40+0x1ed/0x3d0
shrink_zone+0x2ca/0x2e0
kswapd+0x51e/0x990
kthread+0xd8/0xf0
ret_from_fork+0x3f/0x70
which corresponds to the following sanity check in the shadow node
tracking:
BUG_ON(node->count & RADIX_TREE_COUNT_MASK);
The workingset code tracks radix tree nodes that exclusively contain
shadow entries of evicted pages in them, and this (somewhat obscure)
line checks whether there are real pages left that would interfere with
reclaim of the radix tree node under memory pressure.
While discussing ways how fuse might sneak pages into the radix tree
past the workingset code, Miklos pointed to replace_page_cache_page(),
and indeed there is a problem there: it properly accounts for the old
page being removed - __delete_from_page_cache() does that - but then
does a raw raw radix_tree_insert(), not accounting for the replacement
page. Eventually the page count bits in node->count underflow while
leaving the node incorrectly linked to the shadow node LRU.
To address this, make sure replace_page_cache_page() uses the tracked
page insertion code, page_cache_tree_insert(). This fixes the page
accounting and makes sure page-containing nodes are properly unlinked
from the shadow node LRU again.
Also, make the sanity checks a bit less obscure by using the helpers for
checking the number of pages and shadows in a radix tree node.
[mhocko@suse.com: backport for 4.4]
Fixes: 449dd6984d0e ("mm: keep page cache radix tree nodes in check")
Link: http://lkml.kernel.org/r/20160919155822.29498-1-hannes@cmpxchg.org
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Reported-by: Antonio SJ Musumeci <trapexit@spawn.link>
Debugged-by: Miklos Szeredi <miklos@szeredi.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit d3798ae8c6f3767c726403c2ca6ecc317752c9dd upstream.
When the underflow checks were added to workingset_node_shadow_dec(),
they triggered immediately:
kernel BUG at ./include/linux/swap.h:276!
invalid opcode: 0000 [#1] SMP
Modules linked in: isofs usb_storage fuse xt_CHECKSUM ipt_MASQUERADE nf_nat_masquerade_ipv4 tun nf_conntrack_netbios_ns nf_conntrack_broadcast ip6t_REJECT nf_reject_ipv6
soundcore wmi acpi_als pinctrl_sunrisepoint kfifo_buf tpm_tis industrialio acpi_pad pinctrl_intel tpm_tis_core tpm nfsd auth_rpcgss nfs_acl lockd grace sunrpc dm_crypt
CPU: 0 PID: 20929 Comm: blkid Not tainted 4.8.0-rc8-00087-gbe67d60ba944 #1
Hardware name: System manufacturer System Product Name/Z170-K, BIOS 1803 05/06/2016
task: ffff8faa93ecd940 task.stack: ffff8faa7f478000
RIP: page_cache_tree_insert+0xf1/0x100
Call Trace:
__add_to_page_cache_locked+0x12e/0x270
add_to_page_cache_lru+0x4e/0xe0
mpage_readpages+0x112/0x1d0
blkdev_readpages+0x1d/0x20
__do_page_cache_readahead+0x1ad/0x290
force_page_cache_readahead+0xaa/0x100
page_cache_sync_readahead+0x3f/0x50
generic_file_read_iter+0x5af/0x740
blkdev_read_iter+0x35/0x40
__vfs_read+0xe1/0x130
vfs_read+0x96/0x130
SyS_read+0x55/0xc0
entry_SYSCALL_64_fastpath+0x13/0x8f
Code: 03 00 48 8b 5d d8 65 48 33 1c 25 28 00 00 00 44 89 e8 75 19 48 83 c4 18 5b 41 5c 41 5d 41 5e 5d c3 0f 0b 41 bd ef ff ff ff eb d7 <0f> 0b e8 88 68 ef ff 0f 1f 84 00
RIP page_cache_tree_insert+0xf1/0x100
This is a long-standing bug in the way shadow entries are accounted in
the radix tree nodes. The shrinker needs to know when radix tree nodes
contain only shadow entries, no pages, so node->count is split in half
to count shadows in the upper bits and pages in the lower bits.
Unfortunately, the radix tree implementation doesn't know of this and
assumes all entries are in node->count. When there is a shadow entry
directly in root->rnode and the tree is later extended, the radix tree
implementation will copy that entry into the new node and and bump its
node->count, i.e. increases the page count bits. Once the shadow gets
removed and we subtract from the upper counter, node->count underflows
and triggers the warning. Afterwards, without node->count reaching 0
again, the radix tree node is leaked.
Limit shadow entries to when we have actual radix tree nodes and can
count them properly. That means we lose the ability to detect refaults
from files that had only the first page faulted in at eviction time.
Fixes: 449dd6984d0e ("mm: keep page cache radix tree nodes in check")
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Reported-and-tested-by: Linus Torvalds <torvalds@linux-foundation.org>
Reviewed-by: Jan Kara <jack@suse.cz>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit 19be0eaffa3ac7d8eb6784ad9bdbc7d67ed8e619 upstream.
This is an ancient bug that was actually attempted to be fixed once
(badly) by me eleven years ago in commit 4ceb5db9757a ("Fix
get_user_pages() race for write access") but that was then undone due to
problems on s390 by commit f33ea7f404e5 ("fix get_user_pages bug").
In the meantime, the s390 situation has long been fixed, and we can now
fix it by checking the pte_dirty() bit properly (and do it better). The
s390 dirty bit was implemented in abf09bed3cce ("s390/mm: implement
software dirty bits") which made it into v3.9. Earlier kernels will
have to look at the page state itself.
Also, the VM has become more scalable, and what used a purely
theoretical race back then has become easier to trigger.
To fix it, we introduce a new internal FOLL_COW flag to mark the "yes,
we already did a COW" rather than play racy games with FOLL_WRITE that
is very fundamental, and then use the pte dirty flag to validate that
the FOLL_COW flag is still valid.
Reported-and-tested-by: Phil "not Paul" Oester <kernel@linuxace.com>
Acked-by: Hugh Dickins <hughd@google.com>
Reviewed-by: Michal Hocko <mhocko@suse.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Willy Tarreau <w@1wt.eu>
Cc: Nick Piggin <npiggin@gmail.com>
Cc: Greg Thelen <gthelen@google.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit 5b398e416e880159fe55eefd93c6588fa072cd66 upstream.
I hit the following hung task when runing a OOM LTP test case with 4.1
kernel.
Call trace:
[<ffffffc000086a88>] __switch_to+0x74/0x8c
[<ffffffc000a1bae0>] __schedule+0x23c/0x7bc
[<ffffffc000a1c09c>] schedule+0x3c/0x94
[<ffffffc000a1eb84>] rwsem_down_write_failed+0x214/0x350
[<ffffffc000a1e32c>] down_write+0x64/0x80
[<ffffffc00021f794>] __ksm_exit+0x90/0x19c
[<ffffffc0000be650>] mmput+0x118/0x11c
[<ffffffc0000c3ec4>] do_exit+0x2dc/0xa74
[<ffffffc0000c46f8>] do_group_exit+0x4c/0xe4
[<ffffffc0000d0f34>] get_signal+0x444/0x5e0
[<ffffffc000089fcc>] do_signal+0x1d8/0x450
[<ffffffc00008a35c>] do_notify_resume+0x70/0x78
The oom victim cannot terminate because it needs to take mmap_sem for
write while the lock is held by ksmd for read which loops in the page
allocator
ksm_do_scan
scan_get_next_rmap_item
down_read
get_next_rmap_item
alloc_rmap_item #ksmd will loop permanently.
There is no way forward because the oom victim cannot release any memory
in 4.1 based kernel. Since 4.6 we have the oom reaper which would solve
this problem because it would release the memory asynchronously.
Nevertheless we can relax alloc_rmap_item requirements and use
__GFP_NORETRY because the allocation failure is acceptable as ksm_do_scan
would just retry later after the lock got dropped.
Such a patch would be also easy to backport to older stable kernels which
do not have oom_reaper.
While we are at it add GFP_NOWARN so the admin doesn't have to be alarmed
by the allocation failure.
Link: http://lkml.kernel.org/r/1474165570-44398-1-git-send-email-zhongjiang@huawei.com
Signed-off-by: zhong jiang <zhongjiang@huawei.com>
Suggested-by: Hugh Dickins <hughd@google.com>
Suggested-by: Michal Hocko <mhocko@suse.cz>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit b385d21f27d86426472f6ae92a231095f7de2a8d upstream.
init_tlb_ubc() looked unnecessary to me: tlb_ubc is statically
initialized with zeroes in the init_task, and copied from parent to
child while it is quiescent in arch_dup_task_struct(); so I went to
delete it.
But inserted temporary debug WARN_ONs in place of init_tlb_ubc() to
check that it was always empty at that point, and found them firing:
because memcg reclaim can recurse into global reclaim (when allocating
biosets for swapout in my case), and arrive back at the init_tlb_ubc()
in shrink_node_memcg().
Resetting tlb_ubc.flush_required at that point is wrong: if the upper
level needs a deferred TLB flush, but the lower level turns out not to,
we miss a TLB flush. But fortunately, that's the only part of the
protocol that does not nest: with the initialization removed, cpumask
collects bits from upper and lower levels, and flushes TLB when needed.
Fixes: 72b252aed506 ("mm: send one IPI per CPU to TLB flush all entries after unmapping pages")
Signed-off-by: Hugh Dickins <hughd@google.com>
Acked-by: Mel Gorman <mgorman@techsingularity.net>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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[ Upstream commit 65376df582174ffcec9e6471bf5b0dd79ba05e4a ]
Commit b76437579d13 ("procfs: mark thread stack correctly in
proc/<pid>/maps") added [stack:TID] annotation to /proc/<pid>/maps.
Finding the task of a stack VMA requires walking the entire thread list,
turning this into quadratic behavior: a thousand threads means a
thousand stacks, so the rendering of /proc/<pid>/maps needs to look at a
million combinations.
The cost is not in proportion to the usefulness as described in the
patch.
Drop the [stack:TID] annotation to make /proc/<pid>/maps (and
/proc/<pid>/numa_maps) usable again for higher thread counts.
The [stack] annotation inside /proc/<pid>/task/<tid>/maps is retained, as
identifying the stack VMA there is an O(1) operation.
Siddesh said:
"The end users needed a way to identify thread stacks programmatically and
there wasn't a way to do that. I'm afraid I no longer remember (or have
access to the resources that would aid my memory since I changed
employers) the details of their requirement. However, I did do this on my
own time because I thought it was an interesting project for me and nobody
really gave any feedback then as to its utility, so as far as I am
concerned you could roll back the main thread maps information since the
information is available in the thread-specific files"
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: "Kirill A. Shutemov" <kirill@shutemov.name>
Cc: Siddhesh Poyarekar <siddhesh.poyarekar@gmail.com>
Cc: Shaohua Li <shli@fb.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit c17b1f42594eb71b8d3eb5a6dfc907a7eb88a51d upstream.
We account HugeTLB's shared page table to all processes who share it.
The accounting happens during huge_pmd_share().
If somebody populates pud entry under us, we should decrease pagetable's
refcount and decrease nr_pmds of the process.
By mistake, I increase nr_pmds again in this case. :-/ It will lead to
"BUG: non-zero nr_pmds on freeing mm: 2" on process' exit.
Let's fix this by increasing nr_pmds only when we're sure that the page
table will be used.
Link: http://lkml.kernel.org/r/20160617122506.GC6534@node.shutemov.name
Fixes: dc6c9a35b66b ("mm: account pmd page tables to the process")
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Reported-by: zhongjiang <zhongjiang@huawei.com>
Reviewed-by: Mike Kravetz <mike.kravetz@oracle.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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit 649920c6ab93429b94bc7c1aa7c0e8395351be32 upstream.
In powerpc servers with large memory(32TB), we watched several soft
lockups for hugepage under stress tests.
The call traces are as follows:
1.
get_page_from_freelist+0x2d8/0xd50
__alloc_pages_nodemask+0x180/0xc20
alloc_fresh_huge_page+0xb0/0x190
set_max_huge_pages+0x164/0x3b0
2.
prep_new_huge_page+0x5c/0x100
alloc_fresh_huge_page+0xc8/0x190
set_max_huge_pages+0x164/0x3b0
This patch fixes such soft lockups. It is safe to call cond_resched()
there because it is out of spin_lock/unlock section.
Link: http://lkml.kernel.org/r/1469674442-14848-1-git-send-email-hejianet@gmail.com
Signed-off-by: Jia He <hejianet@gmail.com>
Reviewed-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit df08c32ce3be5be138c1dbfcba203314a3a7cd6f upstream.
The name for a bdi of a gendisk is derived from the gendisk's devt.
However, since the gendisk is destroyed before the bdi it leaves a
window where a new gendisk could dynamically reuse the same devt while a
bdi with the same name is still live. Arrange for the bdi to hold a
reference against its "owner" disk device while it is registered.
Otherwise we can hit sysfs duplicate name collisions like the following:
WARNING: CPU: 10 PID: 2078 at fs/sysfs/dir.c:31 sysfs_warn_dup+0x64/0x80
sysfs: cannot create duplicate filename '/devices/virtual/bdi/259:1'
Hardware name: HP ProLiant DL580 Gen8, BIOS P79 05/06/2015
0000000000000286 0000000002c04ad5 ffff88006f24f970 ffffffff8134caec
ffff88006f24f9c0 0000000000000000 ffff88006f24f9b0 ffffffff8108c351
0000001f0000000c ffff88105d236000 ffff88105d1031e0 ffff8800357427f8
Call Trace:
[<ffffffff8134caec>] dump_stack+0x63/0x87
[<ffffffff8108c351>] __warn+0xd1/0xf0
[<ffffffff8108c3cf>] warn_slowpath_fmt+0x5f/0x80
[<ffffffff812a0d34>] sysfs_warn_dup+0x64/0x80
[<ffffffff812a0e1e>] sysfs_create_dir_ns+0x7e/0x90
[<ffffffff8134faaa>] kobject_add_internal+0xaa/0x320
[<ffffffff81358d4e>] ? vsnprintf+0x34e/0x4d0
[<ffffffff8134ff55>] kobject_add+0x75/0xd0
[<ffffffff816e66b2>] ? mutex_lock+0x12/0x2f
[<ffffffff8148b0a5>] device_add+0x125/0x610
[<ffffffff8148b788>] device_create_groups_vargs+0xd8/0x100
[<ffffffff8148b7cc>] device_create_vargs+0x1c/0x20
[<ffffffff811b775c>] bdi_register+0x8c/0x180
[<ffffffff811b7877>] bdi_register_dev+0x27/0x30
[<ffffffff813317f5>] add_disk+0x175/0x4a0
Reported-by: Yi Zhang <yizhan@redhat.com>
Tested-by: Yi Zhang <yizhan@redhat.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Fixed up missing 0 return in bdi_register_owner().
Signed-off-by: Jens Axboe <axboe@fb.com>
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commit 615d66c37c755c49ce022c9e5ac0875d27d2603d upstream.
Since commit 73f576c04b94 ("mm: memcontrol: fix cgroup creation failure
after many small jobs") swap entries do not pin memcg->css.refcnt
directly. Instead, they pin memcg->id.ref. So we should adjust the
reference counters accordingly when moving swap charges between cgroups.
Fixes: 73f576c04b941 ("mm: memcontrol: fix cgroup creation failure after many small jobs")
Link: http://lkml.kernel.org/r/9ce297c64954a42dc90b543bc76106c4a94f07e8.1470219853.git.vdavydov@virtuozzo.com
Signed-off-by: Vladimir Davydov <vdavydov@virtuozzo.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit 1f47b61fb4077936465dcde872a4e5cc4fe708da upstream.
An offline memory cgroup might have anonymous memory or shmem left
charged to it and no swap. Since only swap entries pin the id of an
offline cgroup, such a cgroup will have no id and so an attempt to
swapout its anon/shmem will not store memory cgroup info in the swap
cgroup map. As a result, memcg->swap or memcg->memsw will never get
uncharged from it and any of its ascendants.
Fix this by always charging swapout to the first ancestor cgroup that
hasn't released its id yet.
[hannes@cmpxchg.org: add comment to mem_cgroup_swapout]
[vdavydov@virtuozzo.com: use WARN_ON_ONCE() in mem_cgroup_id_get_online()]
Link: http://lkml.kernel.org/r/20160803123445.GJ13263@esperanza
Fixes: 73f576c04b941 ("mm: memcontrol: fix cgroup creation failure after many small jobs")
Link: http://lkml.kernel.org/r/5336daa5c9a32e776067773d9da655d2dc126491.1470219853.git.vdavydov@virtuozzo.com
Signed-off-by: Vladimir Davydov <vdavydov@virtuozzo.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: <stable@vger.kernel.org> [3.19+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit 73f576c04b9410ed19660f74f97521bee6e1c546 upstream.
The memory controller has quite a bit of state that usually outlives the
cgroup and pins its CSS until said state disappears. At the same time
it imposes a 16-bit limit on the CSS ID space to economically store IDs
in the wild. Consequently, when we use cgroups to contain frequent but
small and short-lived jobs that leave behind some page cache, we quickly
run into the 64k limitations of outstanding CSSs. Creating a new cgroup
fails with -ENOSPC while there are only a few, or even no user-visible
cgroups in existence.
Although pinning CSSs past cgroup removal is common, there are only two
instances that actually need an ID after a cgroup is deleted: cache
shadow entries and swapout records.
Cache shadow entries reference the ID weakly and can deal with the CSS
having disappeared when it's looked up later. They pose no hurdle.
Swap-out records do need to pin the css to hierarchically attribute
swapins after the cgroup has been deleted; though the only pages that
remain swapped out after offlining are tmpfs/shmem pages. And those
references are under the user's control, so they are manageable.
This patch introduces a private 16-bit memcg ID and switches swap and
cache shadow entries over to using that. This ID can then be recycled
after offlining when the CSS remains pinned only by objects that don't
specifically need it.
This script demonstrates the problem by faulting one cache page in a new
cgroup and deleting it again:
set -e
mkdir -p pages
for x in `seq 128000`; do
[ $((x % 1000)) -eq 0 ] && echo $x
mkdir /cgroup/foo
echo $$ >/cgroup/foo/cgroup.procs
echo trex >pages/$x
echo $$ >/cgroup/cgroup.procs
rmdir /cgroup/foo
done
When run on an unpatched kernel, we eventually run out of possible IDs
even though there are no visible cgroups:
[root@ham ~]# ./cssidstress.sh
[...]
65000
mkdir: cannot create directory '/cgroup/foo': No space left on device
After this patch, the IDs get released upon cgroup destruction and the
cache and css objects get released once memory reclaim kicks in.
[hannes@cmpxchg.org: init the IDR]
Link: http://lkml.kernel.org/r/20160621154601.GA22431@cmpxchg.org
Fixes: b2052564e66d ("mm: memcontrol: continue cache reclaim from offlined groups")
Link: http://lkml.kernel.org/r/20160617162516.GD19084@cmpxchg.org
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Reported-by: John Garcia <john.garcia@mesosphere.io>
Reviewed-by: Vladimir Davydov <vdavydov@virtuozzo.com>
Acked-by: Tejun Heo <tj@kernel.org>
Cc: Nikolay Borisov <kernel@kyup.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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uninitialised
commit ef70b6f41cda6270165a6f27b2548ed31cfa3cb2 upstream.
early_page_uninitialised looks up an arbitrary PFN. While a machine
without node 0 will boot with "mm, page_alloc: Always return a valid
node from early_pfn_to_nid", it works because it assumes that nodes are
always in PFN order. This is not guaranteed so this patch adds
robustness by always checking if the node being checked is online.
Link: http://lkml.kernel.org/r/1468008031-3848-4-git-send-email-mgorman@techsingularity.net
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Acked-by: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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