linux-stable.git/mm, branch v4.4.121

mm/early_ioremap: Fix boot hang with earlyprintk=efi,keep

2018-02-25T10:03:41+00:00

[ Upstream commit 7f6f60a1ba52538c16f26930bfbcfe193d9d746a ]

earlyprintk=efi,keep does not work any more with a warning
in mm/early_ioremap.c: WARN_ON(system_state != SYSTEM_BOOTING):
Boot just hangs because of the earlyprintk within the earlyprintk
implementation code itself.

This is caused by a new introduced middle state in:

  69a78ff226fe ("init: Introduce SYSTEM_SCHEDULING state")

early_ioremap() is fine in both SYSTEM_BOOTING and SYSTEM_SCHEDULING
states, original condition should be updated accordingly.

Signed-off-by: Dave Young 
Acked-by: Thomas Gleixner 
Cc: Linus Torvalds 
Cc: Peter Zijlstra 
Cc: bp@suse.de
Cc: linux-efi@vger.kernel.org
Cc: linux-mm@kvack.org
Link: http://lkml.kernel.org/r/20171209041610.GA3249@dhcp-128-65.nay.redhat.com
Signed-off-by: Ingo Molnar 
Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman

Provide a function to create a NUL-terminated string from unterminated data

2018-02-25T10:03:36+00:00

commit f35157417215ec138c920320c746fdb3e04ef1d5 upstream.

Provide a function, kmemdup_nul(), that will create a NUL-terminated string
from an unterminated character array where the length is known in advance.

This is better than kstrndup() in situations where we already know the
string length as the strnlen() in kstrndup() is superfluous.

Signed-off-by: David Howells 
Signed-off-by: Al Viro 
Signed-off-by: Greg Kroah-Hartman

mm,vmscan: Make unregister_shrinker() no-op if register_shrinker() failed.

2018-02-25T10:03:35+00:00

commit bb422a738f6566f7439cd347d54e321e4fe92a9f upstream.

Syzbot caught an oops at unregister_shrinker() because combination of
commit 1d3d4437eae1bb29 ("vmscan: per-node deferred work") and fault
injection made register_shrinker() fail and the caller of
register_shrinker() did not check for failure.

----------
[  554.881422] FAULT_INJECTION: forcing a failure.
[  554.881422] name failslab, interval 1, probability 0, space 0, times 0
[  554.881438] CPU: 1 PID: 13231 Comm: syz-executor1 Not tainted 4.14.0-rc8+ #82
[  554.881443] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
[  554.881445] Call Trace:
[  554.881459]  dump_stack+0x194/0x257
[  554.881474]  ? arch_local_irq_restore+0x53/0x53
[  554.881486]  ? find_held_lock+0x35/0x1d0
[  554.881507]  should_fail+0x8c0/0xa40
[  554.881522]  ? fault_create_debugfs_attr+0x1f0/0x1f0
[  554.881537]  ? check_noncircular+0x20/0x20
[  554.881546]  ? find_next_zero_bit+0x2c/0x40
[  554.881560]  ? ida_get_new_above+0x421/0x9d0
[  554.881577]  ? find_held_lock+0x35/0x1d0
[  554.881594]  ? __lock_is_held+0xb6/0x140
[  554.881628]  ? check_same_owner+0x320/0x320
[  554.881634]  ? lock_downgrade+0x990/0x990
[  554.881649]  ? find_held_lock+0x35/0x1d0
[  554.881672]  should_failslab+0xec/0x120
[  554.881684]  __kmalloc+0x63/0x760
[  554.881692]  ? lock_downgrade+0x990/0x990
[  554.881712]  ? register_shrinker+0x10e/0x2d0
[  554.881721]  ? trace_event_raw_event_module_request+0x320/0x320
[  554.881737]  register_shrinker+0x10e/0x2d0
[  554.881747]  ? prepare_kswapd_sleep+0x1f0/0x1f0
[  554.881755]  ? _down_write_nest_lock+0x120/0x120
[  554.881765]  ? memcpy+0x45/0x50
[  554.881785]  sget_userns+0xbcd/0xe20
(...snipped...)
[  554.898693] kasan: CONFIG_KASAN_INLINE enabled
[  554.898724] kasan: GPF could be caused by NULL-ptr deref or user memory access
[  554.898732] general protection fault: 0000 [#1] SMP KASAN
[  554.898737] Dumping ftrace buffer:
[  554.898741]    (ftrace buffer empty)
[  554.898743] Modules linked in:
[  554.898752] CPU: 1 PID: 13231 Comm: syz-executor1 Not tainted 4.14.0-rc8+ #82
[  554.898755] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
[  554.898760] task: ffff8801d1dbe5c0 task.stack: ffff8801c9e38000
[  554.898772] RIP: 0010:__list_del_entry_valid+0x7e/0x150
[  554.898775] RSP: 0018:ffff8801c9e3f108 EFLAGS: 00010246
[  554.898780] RAX: dffffc0000000000 RBX: 0000000000000000 RCX: 0000000000000000
[  554.898784] RDX: 0000000000000000 RSI: ffff8801c53c6f98 RDI: ffff8801c53c6fa0
[  554.898788] RBP: ffff8801c9e3f120 R08: 1ffff100393c7d55 R09: 0000000000000004
[  554.898791] R10: ffff8801c9e3ef70 R11: 0000000000000000 R12: 0000000000000000
[  554.898795] R13: dffffc0000000000 R14: 1ffff100393c7e45 R15: ffff8801c53c6f98
[  554.898800] FS:  0000000000000000(0000) GS:ffff8801db300000(0000) knlGS:0000000000000000
[  554.898804] CS:  0010 DS: 002b ES: 002b CR0: 0000000080050033
[  554.898807] CR2: 00000000dbc23000 CR3: 00000001c7269000 CR4: 00000000001406e0
[  554.898813] DR0: 0000000020000000 DR1: 0000000020000000 DR2: 0000000000000000
[  554.898816] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600
[  554.898818] Call Trace:
[  554.898828]  unregister_shrinker+0x79/0x300
[  554.898837]  ? perf_trace_mm_vmscan_writepage+0x750/0x750
[  554.898844]  ? down_write+0x87/0x120
[  554.898851]  ? deactivate_super+0x139/0x1b0
[  554.898857]  ? down_read+0x150/0x150
[  554.898864]  ? check_same_owner+0x320/0x320
[  554.898875]  deactivate_locked_super+0x64/0xd0
[  554.898883]  deactivate_super+0x141/0x1b0
----------

Since allowing register_shrinker() callers to call unregister_shrinker()
when register_shrinker() failed can simplify error recovery path, this
patch makes unregister_shrinker() no-op when register_shrinker() failed.
Also, reset shrinker->nr_deferred in case unregister_shrinker() was
by error called twice.

Signed-off-by: Tetsuo Handa 
Signed-off-by: Aliaksei Karaliou 
Reported-by: syzbot 
Cc: Glauber Costa 
Cc: Al Viro 
Signed-off-by: Al Viro 
Signed-off-by: Greg Kroah-Hartman

mm: hide a #warning for COMPILE_TEST

2018-02-22T14:45:00+00:00

commit af27d9403f5b80685b79c88425086edccecaf711 upstream.

We get a warning about some slow configurations in randconfig kernels:

  mm/memory.c:83:2: error: #warning Unfortunate NUMA and NUMA Balancing config, growing page-frame for last_cpupid. [-Werror=cpp]

The warning is reasonable by itself, but gets in the way of randconfig
build testing, so I'm hiding it whenever CONFIG_COMPILE_TEST is set.

The warning was added in 2013 in commit 75980e97dacc ("mm: fold
page->_last_nid into page->flags where possible").

Cc: stable@vger.kernel.org
Signed-off-by: Arnd Bergmann 
Signed-off-by: Linus Torvalds 
Signed-off-by: Greg Kroah-Hartman

kmemleak: add scheduling point to kmemleak_scan()

2018-02-03T16:04:29+00:00

[ Upstream commit bde5f6bc68db51128f875a756e9082a6c6ff7b4c ]

kmemleak_scan() will scan struct page for each node and it can be really
large and resulting in a soft lockup.  We have seen a soft lockup when
do scan while compile kernel:

  watchdog: BUG: soft lockup - CPU#53 stuck for 22s! [bash:10287]
 [...]
  Call Trace:
   kmemleak_scan+0x21a/0x4c0
   kmemleak_write+0x312/0x350
   full_proxy_write+0x5a/0xa0
   __vfs_write+0x33/0x150
   vfs_write+0xad/0x1a0
   SyS_write+0x52/0xc0
   do_syscall_64+0x61/0x1a0
   entry_SYSCALL64_slow_path+0x25/0x25

Fix this by adding cond_resched every MAX_SCAN_SIZE.

Link: http://lkml.kernel.org/r/1511439788-20099-1-git-send-email-xieyisheng1@huawei.com
Signed-off-by: Yisheng Xie 
Suggested-by: Catalin Marinas 
Acked-by: Catalin Marinas 
Cc: Michal Hocko 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds 
Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman

mm, page_alloc: fix potential false positive in __zone_watermark_ok

2018-01-31T11:06:09+00:00

commit b050e3769c6b4013bb937e879fc43bf1847ee819 upstream.

Since commit 97a16fc82a7c ("mm, page_alloc: only enforce watermarks for
order-0 allocations"), __zone_watermark_ok() check for high-order
allocations will shortcut per-migratetype free list checks for
ALLOC_HARDER allocations, and return true as long as there's free page
of any migratetype.  The intention is that ALLOC_HARDER can allocate
from MIGRATE_HIGHATOMIC free lists, while normal allocations can't.

However, as a side effect, the watermark check will then also return
true when there are pages only on the MIGRATE_ISOLATE list, or (prior to
CMA conversion to ZONE_MOVABLE) on the MIGRATE_CMA list.  Since the
allocation cannot actually obtain isolated pages, and might not be able
to obtain CMA pages, this can result in a false positive.

The condition should be rare and perhaps the outcome is not a fatal one.
Still, it's better if the watermark check is correct.  There also
shouldn't be a performance tradeoff here.

Link: http://lkml.kernel.org/r/20171102125001.23708-1-vbabka@suse.cz
Fixes: 97a16fc82a7c ("mm, page_alloc: only enforce watermarks for order-0 allocations")
Signed-off-by: Vlastimil Babka 
Acked-by: Mel Gorman 
Cc: Joonsoo Kim 
Cc: Rik van Riel 
Cc: David Rientjes 
Cc: Johannes Weiner 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds 
Signed-off-by: Greg Kroah-Hartman

cma: fix calculation of aligned offset

2018-01-31T11:06:09+00:00

commit e048cb32f69038aa1c8f11e5c1b331be4181659d upstream.

The align_offset parameter is used by bitmap_find_next_zero_area_off()
to represent the offset of map's base from the previous alignment
boundary; the function ensures that the returned index, plus the
align_offset, honors the specified align_mask.

The logic introduced by commit b5be83e308f7 ("mm: cma: align to physical
address, not CMA region position") has the cma driver calculate the
offset to the *next* alignment boundary.  In most cases, the base
alignment is greater than that specified when making allocations,
resulting in a zero offset whether we align up or down.  In the example
given with the commit, the base alignment (8MB) was half the requested
alignment (16MB) so the math also happened to work since the offset is
8MB in both directions.  However, when requesting allocations with an
alignment greater than twice that of the base, the returned index would
not be correctly aligned.

Also, the align_order arguments of cma_bitmap_aligned_mask() and
cma_bitmap_aligned_offset() should not be negative so the argument type
was made unsigned.

Fixes: b5be83e308f7 ("mm: cma: align to physical address, not CMA region position")
Link: http://lkml.kernel.org/r/20170628170742.2895-1-opendmb@gmail.com
Signed-off-by: Angus Clark 
Signed-off-by: Doug Berger 
Acked-by: Gregory Fong 
Cc: Doug Berger 
Cc: Angus Clark 
Cc: Laura Abbott 
Cc: Vlastimil Babka 
Cc: Greg Kroah-Hartman 
Cc: Lucas Stach 
Cc: Catalin Marinas 
Cc: Shiraz Hashim 
Cc: Jaewon Kim 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds 
Signed-off-by: Vlastimil Babka 
Signed-off-by: Greg Kroah-Hartman

hwpoison, memcg: forcibly uncharge LRU pages

2018-01-31T11:06:09+00:00

commit 18365225f0440d09708ad9daade2ec11275c3df9 upstream.

Laurent Dufour has noticed that hwpoinsoned pages are kept charged.  In
his particular case he has hit a bad_page("page still charged to
cgroup") when onlining a hwpoison page.  While this looks like something
that shouldn't happen in the first place because onlining hwpages and
returning them to the page allocator makes only little sense it shows a
real problem.

hwpoison pages do not get freed usually so we do not uncharge them (at
least not since commit 0a31bc97c80c ("mm: memcontrol: rewrite uncharge
API")).  Each charge pins memcg (since e8ea14cc6ead ("mm: memcontrol:
take a css reference for each charged page")) as well and so the
mem_cgroup and the associated state will never go away.  Fix this leak
by forcibly uncharging a LRU hwpoisoned page in delete_from_lru_cache().
We also have to tweak uncharge_list because it cannot rely on zero ref
count for these pages.

[akpm@linux-foundation.org: coding-style fixes]
Fixes: 0a31bc97c80c ("mm: memcontrol: rewrite uncharge API")
Link: http://lkml.kernel.org/r/20170502185507.GB19165@dhcp22.suse.cz
Signed-off-by: Michal Hocko 
Reported-by: Laurent Dufour 
Tested-by: Laurent Dufour 
Reviewed-by: Balbir Singh 
Reviewed-by: Naoya Horiguchi 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds 
Signed-off-by: Greg Kroah-Hartman

mm/mmap.c: do not blow on PROT_NONE MAP_FIXED holes in the stack

2018-01-31T11:06:09+00:00

commit 561b5e0709e4a248c67d024d4d94b6e31e3edf2f upstream.

Commit 1be7107fbe18 ("mm: larger stack guard gap, between vmas") has
introduced a regression in some rust and Java environments which are
trying to implement their own stack guard page.  They are punching a new
MAP_FIXED mapping inside the existing stack Vma.

This will confuse expand_{downwards,upwards} into thinking that the
stack expansion would in fact get us too close to an existing non-stack
vma which is a correct behavior wrt safety.  It is a real regression on
the other hand.

Let's work around the problem by considering PROT_NONE mapping as a part
of the stack.  This is a gros hack but overflowing to such a mapping
would trap anyway an we only can hope that usespace knows what it is
doing and handle it propely.

Fixes: 1be7107fbe18 ("mm: larger stack guard gap, between vmas")
Link: http://lkml.kernel.org/r/20170705182849.GA18027@dhcp22.suse.cz
Signed-off-by: Michal Hocko 
Debugged-by: Vlastimil Babka 
Cc: Ben Hutchings 
Cc: Willy Tarreau 
Cc: Oleg Nesterov 
Cc: Rik van Riel 
Cc: Hugh Dickins 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds 
Signed-off-by: Greg Kroah-Hartman

zswap: don't param_set_charp while holding spinlock

2018-01-17T08:35:27+00:00

commit fd5bb66cd934987e49557455b6497fc006521940 upstream.

Change the zpool/compressor param callback function to release the
zswap_pools_lock spinlock before calling param_set_charp, since that
function may sleep when it calls kmalloc with GFP_KERNEL.

While this problem has existed for a while, I wasn't able to trigger it
using a tight loop changing either/both the zpool and compressor params; I
think it's very unlikely to be an issue on the stable kernels, especially
since most zswap users will change the compressor and/or zpool from sysfs
only one time each boot - or zero times, if they add the params to the
kernel boot.

Fixes: c99b42c3529e ("zswap: use charp for zswap param strings")
Link: http://lkml.kernel.org/r/20170126155821.4545-1-ddstreet@ieee.org
Signed-off-by: Dan Streetman 
Reported-by: Sergey Senozhatsky 
Cc: Michal Hocko 
Cc: Minchan Kim 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds 
Signed-off-by: Vlastimil Babka 
Signed-off-by: Greg Kroah-Hartman