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Rong Chen has reported the following boot crash:
PGD 0 P4D 0
Oops: 0000 [#1] PREEMPT SMP PTI
CPU: 1 PID: 239 Comm: udevd Not tainted 5.0.0-rc4-00149-gefad4e4 #1
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1 04/01/2014
RIP: 0010:page_mapping+0x12/0x80
Code: 5d c3 48 89 df e8 0e ad 02 00 85 c0 75 da 89 e8 5b 5d c3 0f 1f 44 00 00 53 48 89 fb 48 8b 43 08 48 8d 50 ff a8 01 48 0f 45 da <48> 8b 53 08 48 8d 42 ff 83 e2 01 48 0f 44 c3 48 83 38 ff 74 2f 48
RSP: 0018:ffff88801fa87cd8 EFLAGS: 00010202
RAX: ffffffffffffffff RBX: fffffffffffffffe RCX: 000000000000000a
RDX: fffffffffffffffe RSI: ffffffff820b9a20 RDI: ffff88801e5c0000
RBP: 6db6db6db6db6db7 R08: ffff88801e8bb000 R09: 0000000001b64d13
R10: ffff88801fa87cf8 R11: 0000000000000001 R12: ffff88801e640000
R13: ffffffff820b9a20 R14: ffff88801f145258 R15: 0000000000000001
FS: 00007fb2079817c0(0000) GS:ffff88801dd00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000006 CR3: 000000001fa82000 CR4: 00000000000006a0
Call Trace:
__dump_page+0x14/0x2c0
is_mem_section_removable+0x24c/0x2c0
removable_show+0x87/0xa0
dev_attr_show+0x25/0x60
sysfs_kf_seq_show+0xba/0x110
seq_read+0x196/0x3f0
__vfs_read+0x34/0x180
vfs_read+0xa0/0x150
ksys_read+0x44/0xb0
do_syscall_64+0x5e/0x4a0
entry_SYSCALL_64_after_hwframe+0x49/0xbe
and bisected it down to commit efad4e475c31 ("mm, memory_hotplug:
is_mem_section_removable do not pass the end of a zone").
The reason for the crash is that the mapping is garbage for poisoned
(uninitialized) page. This shouldn't happen as all pages in the zone's
boundary should be initialized.
Later debugging revealed that the actual problem is an off-by-one when
evaluating the end_page. 'start_pfn + nr_pages' resp 'zone_end_pfn'
refers to a pfn after the range and as such it might belong to a
differen memory section.
This along with CONFIG_SPARSEMEM then makes the loop condition
completely bogus because a pointer arithmetic doesn't work for pages
from two different sections in that memory model.
Fix the issue by reworking is_pageblock_removable to be pfn based and
only use struct page where necessary. This makes the code slightly
easier to follow and we will remove the problematic pointer arithmetic
completely.
Link: http://lkml.kernel.org/r/20190218181544.14616-1-mhocko@kernel.org
Fixes: efad4e475c31 ("mm, memory_hotplug: is_mem_section_removable do not pass the end of a zone")
Signed-off-by: Michal Hocko <mhocko@suse.com>
Reported-by: <rong.a.chen@intel.com>
Tested-by: <rong.a.chen@intel.com>
Acked-by: Mike Rapoport <rppt@linux.ibm.com>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Cc: Matthew Wilcox <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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memdump_user usually gets fed unchecked userspace input. Blasting a
full backtrace into dmesg every time is a bit excessive - I'm not sure
on the kernel rule in general, but at least in drm we're trying not to
let unpriviledge userspace spam the logs freely. Definitely not entire
warning backtraces.
It also means more filtering for our CI, because our testsuite exercises
these corner cases and so hits these a lot.
Link: http://lkml.kernel.org/r/20190220204058.11676-1-daniel.vetter@ffwll.ch
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Michal Hocko <mhocko@suse.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Cc: Mike Rapoport <rppt@linux.vnet.ibm.com>
Cc: Roman Gushchin <guro@fb.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Jan Stancek <jstancek@redhat.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Huang Ying <ying.huang@intel.com>
Cc: Bartosz Golaszewski <brgl@bgdev.pl>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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In process_slab(), "p = get_freepointer()" could return a tagged
pointer, but "addr = page_address()" always return a native pointer. As
the result, slab_index() is messed up here,
return (p - addr) / s->size;
All other callers of slab_index() have the same situation where "addr"
is from page_address(), so just need to untag "p".
# cat /sys/kernel/slab/hugetlbfs_inode_cache/alloc_calls
Unable to handle kernel paging request at virtual address 2bff808aa4856d48
Mem abort info:
ESR = 0x96000007
Exception class = DABT (current EL), IL = 32 bits
SET = 0, FnV = 0
EA = 0, S1PTW = 0
Data abort info:
ISV = 0, ISS = 0x00000007
CM = 0, WnR = 0
swapper pgtable: 64k pages, 48-bit VAs, pgdp = 0000000002498338
[2bff808aa4856d48] pgd=00000097fcfd0003, pud=00000097fcfd0003, pmd=00000097fca30003, pte=00e8008b24850712
Internal error: Oops: 96000007 [#1] SMP
CPU: 3 PID: 79210 Comm: read_all Tainted: G L 5.0.0-rc7+ #84
Hardware name: HPE Apollo 70 /C01_APACHE_MB , BIOS L50_5.13_1.0.6 07/10/2018
pstate: 00400089 (nzcv daIf +PAN -UAO)
pc : get_map+0x78/0xec
lr : get_map+0xa0/0xec
sp : aeff808989e3f8e0
x29: aeff808989e3f940 x28: ffff800826200000
x27: ffff100012d47000 x26: 9700000000002500
x25: 0000000000000001 x24: 52ff8008200131f8
x23: 52ff8008200130a0 x22: 52ff800820013098
x21: ffff800826200000 x20: ffff100013172ba0
x19: 2bff808a8971bc00 x18: ffff1000148f5538
x17: 000000000000001b x16: 00000000000000ff
x15: ffff1000148f5000 x14: 00000000000000d2
x13: 0000000000000001 x12: 0000000000000000
x11: 0000000020000002 x10: 2bff808aa4856d48
x9 : 0000020000000000 x8 : 68ff80082620ebb0
x7 : 0000000000000000 x6 : ffff1000105da1dc
x5 : 0000000000000000 x4 : 0000000000000000
x3 : 0000000000000010 x2 : 2bff808a8971bc00
x1 : ffff7fe002098800 x0 : ffff80082620ceb0
Process read_all (pid: 79210, stack limit = 0x00000000f65b9361)
Call trace:
get_map+0x78/0xec
process_slab+0x7c/0x47c
list_locations+0xb0/0x3c8
alloc_calls_show+0x34/0x40
slab_attr_show+0x34/0x48
sysfs_kf_seq_show+0x2e4/0x570
kernfs_seq_show+0x12c/0x1a0
seq_read+0x48c/0xf84
kernfs_fop_read+0xd4/0x448
__vfs_read+0x94/0x5d4
vfs_read+0xcc/0x194
ksys_read+0x6c/0xe8
__arm64_sys_read+0x68/0xb0
el0_svc_handler+0x230/0x3bc
el0_svc+0x8/0xc
Code: d3467d2a 9ac92329 8b0a0e6a f9800151 (c85f7d4b)
---[ end trace a383a9a44ff13176 ]---
Kernel panic - not syncing: Fatal exception
SMP: stopping secondary CPUs
SMP: failed to stop secondary CPUs 1-7,32,40,127
Kernel Offset: disabled
CPU features: 0x002,20000c18
Memory Limit: none
---[ end Kernel panic - not syncing: Fatal exception ]---
Link: http://lkml.kernel.org/r/20190220020251.82039-1-cai@lca.pw
Signed-off-by: Qian Cai <cai@lca.pw>
Reviewed-by: Andrey Konovalov <andreyknvl@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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kasan_slab_alloc() calls in kmem_cache_alloc() and kmem_cache_alloc_node()
are redundant as they are already called via slab_alloc/slab_alloc_node()->
slab_post_alloc_hook()->kasan_slab_alloc(). Remove them.
Link: http://lkml.kernel.org/r/4ca1655cdcfc4379c49c50f7bf80f81c4ad01485.1550602886.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Tested-by: Qian Cai <cai@lca.pw>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Evgeniy Stepanov <eugenis@google.com>
Cc: Kostya Serebryany <kcc@google.com>
Cc: Vincenzo Frascino <vincenzo.frascino@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Similarly to "kasan, slub: move kasan_poison_slab hook before
page_address", move kasan_poison_slab() before alloc_slabmgmt(), which
calls page_address(), to make page_address() return value to be
non-tagged. This, combined with calling kasan_reset_tag() for off-slab
slab management object, leads to freelist being stored non-tagged.
Link: http://lkml.kernel.org/r/dfb53b44a4d00de3879a05a9f04c1f55e584f7a1.1550602886.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Tested-by: Qian Cai <cai@lca.pw>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Evgeniy Stepanov <eugenis@google.com>
Cc: Kostya Serebryany <kcc@google.com>
Cc: Vincenzo Frascino <vincenzo.frascino@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Similarly to commit 96fedce27e13 ("kasan: make tag based mode work with
CONFIG_HARDENED_USERCOPY"), we need to reset pointer tags in
__check_heap_object() in mm/slab.c before doing any pointer math.
Link: http://lkml.kernel.org/r/9a5c0f958db10e69df5ff9f2b997866b56b7effc.1550602886.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Tested-by: Qian Cai <cai@lca.pw>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Evgeniy Stepanov <eugenis@google.com>
Cc: Kostya Serebryany <kcc@google.com>
Cc: Vincenzo Frascino <vincenzo.frascino@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Similarly to commit 0d0c8de8788b ("kasan: mark file common so ftrace
doesn't trace it") add the -pg flag to mm/kasan/tags.c to prevent
conflicts with tracing.
Link: http://lkml.kernel.org/r/9c4c3ce5ccfb894c7fe66d91de7c1da2787b4da4.1550602886.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Reported-by: Qian Cai <cai@lca.pw>
Tested-by: Qian Cai <cai@lca.pw>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Vincenzo Frascino <vincenzo.frascino@arm.com>
Cc: Kostya Serebryany <kcc@google.com>
Cc: Evgeniy Stepanov <eugenis@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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There are two issues with assigning random percpu seeds right now:
1. We use for_each_possible_cpu() to iterate over cpus, but cpumask is
not set up yet at the moment of kasan_init(), and thus we only set
the seed for cpu #0.
2. A call to get_random_u32() always returns the same number and produces
a message in dmesg, since the random subsystem is not yet initialized.
Fix 1 by calling kasan_init_tags() after cpumask is set up.
Fix 2 by using get_cycles() instead of get_random_u32(). This gives us
lower quality random numbers, but it's good enough, as KASAN is meant to
be used as a debugging tool and not a mitigation.
Link: http://lkml.kernel.org/r/1f815cc914b61f3516ed4cc9bfd9eeca9bd5d9de.1550677973.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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tmpfs has a peculiarity of accounting hard links as if they were
separate inodes: so that when the number of inodes is limited, as it is
by default, a user cannot soak up an unlimited amount of unreclaimable
dcache memory just by repeatedly linking a file.
But when v3.11 added O_TMPFILE, and the ability to use linkat() on the
fd, we missed accommodating this new case in tmpfs: "df -i" shows that
an extra "inode" remains accounted after the file is unlinked and the fd
closed and the actual inode evicted. If a user repeatedly links
tmpfiles into a tmpfs, the limit will be hit (ENOSPC) even after they
are deleted.
Just skip the extra reservation from shmem_link() in this case: there's
a sense in which this first link of a tmpfile is then cheaper than a
hard link of another file, but the accounting works out, and there's
still good limiting, so no need to do anything more complicated.
Link: http://lkml.kernel.org/r/alpine.LSU.2.11.1902182134370.7035@eggly.anvils
Fixes: f4e0c30c191 ("allow the temp files created by open() to be linked to")
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Hugh Dickins <hughd@google.com>
Reported-by: Matej Kupljen <matej.kupljen@gmail.com>
Acked-by: 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>
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Since for_each_cpu(cpu, mask) added by commit 2d3854a37e8b767a
("cpumask: introduce new API, without changing anything") did not
evaluate the mask argument if NR_CPUS == 1 due to CONFIG_SMP=n,
lru_add_drain_all() is hitting WARN_ON() at __flush_work() added by
commit 4d43d395fed12463 ("workqueue: Try to catch flush_work() without
INIT_WORK().") by unconditionally calling flush_work() [1].
Workaround this issue by using CONFIG_SMP=n specific lru_add_drain_all
implementation. There is no real need to defer the implementation to
the workqueue as the draining is going to happen on the local cpu. So
alias lru_add_drain_all to lru_add_drain which does all the necessary
work.
[akpm@linux-foundation.org: fix various build warnings]
[1] https://lkml.kernel.org/r/18a30387-6aa5-6123-e67c-57579ecc3f38@roeck-us.net
Link: http://lkml.kernel.org/r/20190213124334.GH4525@dhcp22.suse.cz
Signed-off-by: Michal Hocko <mhocko@suse.com>
Reported-by: Guenter Roeck <linux@roeck-us.net>
Debugged-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Yury Norov reported that an arm64 KVM instance could not boot since
after v5.0-rc1 and could addressed by reverting the patches
1c30844d2dfe272d58c ("mm: reclaim small amounts of memory when an external
73444bc4d8f92e46a20 ("mm, page_alloc: do not wake kswapd with zone lock held")
The problem is that a division by zero error is possible if boosting
occurs very early in boot if the system has very little memory. This
patch avoids the division by zero error.
Link: http://lkml.kernel.org/r/20190213143012.GT9565@techsingularity.net
Fixes: 1c30844d2dfe ("mm: reclaim small amounts of memory when an external fragmentation event occurs")
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Reported-by: Yury Norov <yury.norov@gmail.com>
Tested-by: Yury Norov <yury.norov@gmail.com>
Tested-by: Will Deacon <will.deacon@arm.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Evaluating page_mapping() on a poisoned page ends up dereferencing junk
and making PF_POISONED_CHECK() considerably crashier than intended:
Unable to handle kernel NULL pointer dereference at virtual address 0000000000000006
Mem abort info:
ESR = 0x96000005
Exception class = DABT (current EL), IL = 32 bits
SET = 0, FnV = 0
EA = 0, S1PTW = 0
Data abort info:
ISV = 0, ISS = 0x00000005
CM = 0, WnR = 0
user pgtable: 4k pages, 39-bit VAs, pgdp = 00000000c2f6ac38
[0000000000000006] pgd=0000000000000000, pud=0000000000000000
Internal error: Oops: 96000005 [#1] PREEMPT SMP
Modules linked in:
CPU: 2 PID: 491 Comm: bash Not tainted 5.0.0-rc1+ #1
Hardware name: ARM LTD ARM Juno Development Platform/ARM Juno Development Platform, BIOS EDK II Dec 17 2018
pstate: 00000005 (nzcv daif -PAN -UAO)
pc : page_mapping+0x18/0x118
lr : __dump_page+0x1c/0x398
Process bash (pid: 491, stack limit = 0x000000004ebd4ecd)
Call trace:
page_mapping+0x18/0x118
__dump_page+0x1c/0x398
dump_page+0xc/0x18
remove_store+0xbc/0x120
dev_attr_store+0x18/0x28
sysfs_kf_write+0x40/0x50
kernfs_fop_write+0x130/0x1d8
__vfs_write+0x30/0x180
vfs_write+0xb4/0x1a0
ksys_write+0x60/0xd0
__arm64_sys_write+0x18/0x20
el0_svc_common+0x94/0xf8
el0_svc_handler+0x68/0x70
el0_svc+0x8/0xc
Code: f9400401 d1000422 f240003f 9a801040 (f9400402)
---[ end trace cdb5eb5bf435cecb ]---
Fix that by not inspecting the mapping until we've determined that it's
likely to be valid. Now the above condition still ends up stopping the
kernel, but in the correct manner:
page:ffffffbf20000000 is uninitialized and poisoned
raw: ffffffffffffffff ffffffffffffffff ffffffffffffffff ffffffffffffffff
raw: ffffffffffffffff ffffffffffffffff ffffffffffffffff ffffffffffffffff
page dumped because: VM_BUG_ON_PAGE(PagePoisoned(p))
------------[ cut here ]------------
kernel BUG at ./include/linux/mm.h:1006!
Internal error: Oops - BUG: 0 [#1] PREEMPT SMP
Modules linked in:
CPU: 1 PID: 483 Comm: bash Not tainted 5.0.0-rc1+ #3
Hardware name: ARM LTD ARM Juno Development Platform/ARM Juno Development Platform, BIOS EDK II Dec 17 2018
pstate: 40000005 (nZcv daif -PAN -UAO)
pc : remove_store+0xbc/0x120
lr : remove_store+0xbc/0x120
...
Link: http://lkml.kernel.org/r/03b53ee9d7e76cda4b9b5e1e31eea080db033396.1550071778.git.robin.murphy@arm.com
Fixes: 1c6fb1d89e73 ("mm: print more information about mapping in __dump_page")
Signed-off-by: Robin Murphy <robin.murphy@arm.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>
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Enabling SLUB_DEBUG's SLAB_CONSISTENCY_CHECKS with KASAN_SW_TAGS
triggers endless false positives during boot below due to
check_valid_pointer() checks tagged pointers which have no addresses
that is valid within slab pages:
BUG radix_tree_node (Tainted: G B ): Freelist Pointer check fails
-----------------------------------------------------------------------------
INFO: Slab objects=69 used=69 fp=0x (null) flags=0x7ffffffc000200
INFO: Object @offset=15060037153926966016 fp=0x
Redzone: bb bb bb bb bb bb bb bb bb bb bb bb bb bb bb bb ................
Object : 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
Object : 00 00 00 00 00 00 00 00 18 6b 06 00 08 80 ff d0 .........k......
Object : 18 6b 06 00 08 80 ff d0 00 00 00 00 00 00 00 00 .k..............
Object : 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
Object : 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
Object : 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
Object : 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
Object : 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
Object : 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
Object : 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
Object : 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
Object : 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
Object : 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
Object : 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
Object : 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
Object : 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
Object : 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
Object : 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
Object : 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
Object : 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
Object : 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
Object : 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
Object : 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
Object : 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
Object : 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
Object : 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
Object : 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
Object : 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
Object : 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
Object : 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
Object : 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
Object : 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
Object : 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
Object : 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
Object : 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
Object : 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
Redzone: bb bb bb bb bb bb bb bb ........
Padding: 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a ZZZZZZZZZZZZZZZZ
CPU: 0 PID: 0 Comm: swapper/0 Tainted: G B 5.0.0-rc5+ #18
Call trace:
dump_backtrace+0x0/0x450
show_stack+0x20/0x2c
__dump_stack+0x20/0x28
dump_stack+0xa0/0xfc
print_trailer+0x1bc/0x1d0
object_err+0x40/0x50
alloc_debug_processing+0xf0/0x19c
___slab_alloc+0x554/0x704
kmem_cache_alloc+0x2f8/0x440
radix_tree_node_alloc+0x90/0x2fc
idr_get_free+0x1e8/0x6d0
idr_alloc_u32+0x11c/0x2a4
idr_alloc+0x74/0xe0
worker_pool_assign_id+0x5c/0xbc
workqueue_init_early+0x49c/0xd50
start_kernel+0x52c/0xac4
FIX radix_tree_node: Marking all objects used
Link: http://lkml.kernel.org/r/20190209044128.3290-1-cai@lca.pw
Signed-off-by: Qian Cai <cai@lca.pw>
Reviewed-by: Andrey Konovalov <andreyknvl@google.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
When CONFIG_KASAN_SW_TAGS is enabled, ptr_addr might be tagged. Normally,
this doesn't cause any issues, as both set_freepointer() and
get_freepointer() are called with a pointer with the same tag. However,
there are some issues with CONFIG_SLUB_DEBUG code. For example, when
__free_slub() iterates over objects in a cache, it passes untagged
pointers to check_object(). check_object() in turns calls
get_freepointer() with an untagged pointer, which causes the freepointer
to be restored incorrectly.
Add kasan_reset_tag to freelist_ptr(). Also add a detailed comment.
Link: http://lkml.kernel.org/r/bf858f26ef32eb7bd24c665755b3aee4bc58d0e4.1550103861.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Reported-by: Qian Cai <cai@lca.pw>
Tested-by: Qian Cai <cai@lca.pw>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
CONFIG_SLAB_FREELIST_HARDENED hashes freelist pointer with the address of
the object where the pointer gets stored. With tag based KASAN we don't
account for that when building freelist, as we call set_freepointer() with
the first argument untagged. This patch changes the code to properly
propagate tags throughout the loop.
Link: http://lkml.kernel.org/r/3df171559c52201376f246bf7ce3184fe21c1dc7.1549921721.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Reported-by: Qian Cai <cai@lca.pw>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Vincenzo Frascino <vincenzo.frascino@arm.com>
Cc: Kostya Serebryany <kcc@google.com>
Cc: Evgeniy Stepanov <eugenis@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
With tag based KASAN page_address() looks at the page flags to see whether
the resulting pointer needs to have a tag set. Since we don't want to set
a tag when page_address() is called on SLAB pages, we call
page_kasan_tag_reset() in kasan_poison_slab(). However in allocate_slab()
page_address() is called before kasan_poison_slab(). Fix it by changing
the order.
[andreyknvl@google.com: fix compilation error when CONFIG_SLUB_DEBUG=n]
Link: http://lkml.kernel.org/r/ac27cc0bbaeb414ed77bcd6671a877cf3546d56e.1550066133.git.andreyknvl@google.com
Link: http://lkml.kernel.org/r/cd895d627465a3f1c712647072d17f10883be2a1.1549921721.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Evgeniy Stepanov <eugenis@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Kostya Serebryany <kcc@google.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Qian Cai <cai@lca.pw>
Cc: Vincenzo Frascino <vincenzo.frascino@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
kmemleak keeps two global variables, min_addr and max_addr, which store
the range of valid (encountered by kmemleak) pointer values, which it
later uses to speed up pointer lookup when scanning blocks.
With tagged pointers this range will get bigger than it needs to be. This
patch makes kmemleak untag pointers before saving them to min_addr and
max_addr and when performing a lookup.
Link: http://lkml.kernel.org/r/16e887d442986ab87fe87a755815ad92fa431a5f.1550066133.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Tested-by: Qian Cai <cai@lca.pw>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Evgeniy Stepanov <eugenis@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Kostya Serebryany <kcc@google.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Vincenzo Frascino <vincenzo.frascino@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
Right now we call kmemleak hooks before assigning tags to pointers in
KASAN hooks. As a result, when an objects gets allocated, kmemleak sees a
differently tagged pointer, compared to the one it sees when the object
gets freed. Fix it by calling KASAN hooks before kmemleak's ones.
Link: http://lkml.kernel.org/r/cd825aa4897b0fc37d3316838993881daccbe9f5.1549921721.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Reported-by: Qian Cai <cai@lca.pw>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Evgeniy Stepanov <eugenis@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Kostya Serebryany <kcc@google.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Vincenzo Frascino <vincenzo.frascino@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
When an object is kmalloc()'ed, two hooks are called: kasan_slab_alloc()
and kasan_kmalloc(). Right now we assign a tag twice, once in each of the
hooks. Fix it by assigning a tag only in the former hook.
Link: http://lkml.kernel.org/r/ce8c6431da735aa7ec051fd6497153df690eb021.1549921721.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Evgeniy Stepanov <eugenis@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Kostya Serebryany <kcc@google.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Qian Cai <cai@lca.pw>
Cc: Vincenzo Frascino <vincenzo.frascino@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
The system call, get_mempolicy() [1], passes an unsigned long *nodemask
pointer and an unsigned long maxnode argument which specifies the length
of the user's nodemask array in bits (which is rounded up). The manual
page says that if the maxnode value is too small, get_mempolicy will
return EINVAL but there is no system call to return this minimum value.
To determine this value, some programs search /proc/<pid>/status for a
line starting with "Mems_allowed:" and use the number of digits in the
mask to determine the minimum value. A recent change to the way this line
is formatted [2] causes these programs to compute a value less than
MAX_NUMNODES so get_mempolicy() returns EINVAL.
Change get_mempolicy(), the older compat version of get_mempolicy(), and
the copy_nodes_to_user() function to use nr_node_ids instead of
MAX_NUMNODES, thus preserving the defacto method of computing the minimum
size for the nodemask array and the maxnode argument.
[1] http://man7.org/linux/man-pages/man2/get_mempolicy.2.html
[2] https://lore.kernel.org/lkml/1545405631-6808-1-git-send-email-longman@redhat.com
Link: http://lkml.kernel.org/r/20190211180245.22295-1-rcampbell@nvidia.com
Fixes: 4fb8e5b89bcbbbb ("include/linux/nodemask.h: use nr_node_ids (not MAX_NUMNODES) in __nodemask_pr_numnodes()")
Signed-off-by: Ralph Campbell <rcampbell@nvidia.com>
Suggested-by: Alexander Duyck <alexander.duyck@gmail.com>
Cc: Waiman Long <longman@redhat.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
Pull networking fixes from David Miller:
1) Fix suspend and resume in mt76x0u USB driver, from Stanislaw
Gruszka.
2) Missing memory barriers in xsk, from Magnus Karlsson.
3) rhashtable fixes in mac80211 from Herbert Xu.
4) 32-bit MIPS eBPF JIT fixes from Paul Burton.
5) Fix for_each_netdev_feature() on big endian, from Hauke Mehrtens.
6) GSO validation fixes from Willem de Bruijn.
7) Endianness fix for dwmac4 timestamp handling, from Alexandre Torgue.
8) More strict checks in tcp_v4_err(), from Eric Dumazet.
9) af_alg_release should NULL out the sk after the sock_put(), from Mao
Wenan.
10) Missing unlock in mac80211 mesh error path, from Wei Yongjun.
11) Missing device put in hns driver, from Salil Mehta.
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (44 commits)
sky2: Increase D3 delay again
vhost: correctly check the return value of translate_desc() in log_used()
net: netcp: Fix ethss driver probe issue
net: hns: Fixes the missing put_device in positive leg for roce reset
net: stmmac: Fix a race in EEE enable callback
qed: Fix iWARP syn packet mac address validation.
qed: Fix iWARP buffer size provided for syn packet processing.
r8152: Add support for MAC address pass through on RTL8153-BD
mac80211: mesh: fix missing unlock on error in table_path_del()
net/mlx4_en: fix spelling mistake: "quiting" -> "quitting"
net: crypto set sk to NULL when af_alg_release.
net: Do not allocate page fragments that are not skb aligned
mm: Use fixed constant in page_frag_alloc instead of size + 1
tcp: tcp_v4_err() should be more careful
tcp: clear icsk_backoff in tcp_write_queue_purge()
net: mv643xx_eth: disable clk on error path in mv643xx_eth_shared_probe()
qmi_wwan: apply SET_DTR quirk to Sierra WP7607
net: stmmac: handle endianness in dwmac4_get_timestamp
doc: Mention MSG_ZEROCOPY implementation for UDP
mlxsw: __mlxsw_sp_port_headroom_set(): Fix a use of local variable
...
|
|
This patch replaces the size + 1 value introduced with the recent fix for 1
byte allocs with a constant value.
The idea here is to reduce code overhead as the previous logic would have
to read size into a register, then increment it, and write it back to
whatever field was being used. By using a constant we can avoid those
memory reads and arithmetic operations in favor of just encoding the
maximum value into the operation itself.
Fixes: 2c2ade81741c ("mm: page_alloc: fix ref bias in page_frag_alloc() for 1-byte allocs")
Signed-off-by: Alexander Duyck <alexander.h.duyck@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
|
|
In the irqchip and EFI code, we have what basically amounts to a quirk
to work around a peculiarity in the GICv3 architecture, which permits
the system memory address of LPI tables to be programmable only once
after a CPU reset. This means kexec kernels must use the same memory
as the first kernel, and thus ensure that this memory has not been
given out for other purposes by the time the ITS init code runs, which
is not very early for secondary CPUs.
On systems with many CPUs, these reservations could overflow the
memblock reservation table, and this was addressed in commit:
eff896288872 ("efi/arm: Defer persistent reservations until after paging_init()")
However, this turns out to have made things worse, since the allocation
of page tables and heap space for the resized memblock reservation table
itself may overwrite the regions we are attempting to reserve, which may
cause all kinds of corruption, also considering that the ITS will still
be poking bits into that memory in response to incoming MSIs.
So instead, let's grow the static memblock reservation table on such
systems so it can accommodate these reservations at an earlier time.
This will permit us to revert the above commit in a subsequent patch.
[ mingo: Minor cleanups. ]
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Acked-by: Mike Rapoport <rppt@linux.ibm.com>
Acked-by: Will Deacon <will.deacon@arm.com>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-efi@vger.kernel.org
Link: http://lkml.kernel.org/r/20190215123333.21209-2-ard.biesheuvel@linaro.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
|
|
Pull networking fixes from David Miller:
1) Fix MAC address setting in mac80211 pmsr code, from Johannes Berg.
2) Probe SFP modules after being attached, from Russell King.
3) Byte ordering bug in SMC rx_curs_confirmed code, from Ursula Braun.
4) Revert some r8169 changes that are causing regressions, from Heiner
Kallweit.
5) Fix spurious connection timeouts in netfilter nat code, from Florian
Westphal.
6) SKB leak in tipc, from Hoang Le.
7) Short packet checkum issue in mlx4, similar to a previous mlx5
change, from Saeed Mahameed. The issue is that whilst padding bytes
are usually zero, it is not guarateed and the hardware doesn't take
the padding bytes into consideration when generating the checksum.
8) Fix various races in cls_tcindex, from Cong Wang.
9) Need to set stream ext to NULL before freeing in SCTP code, from Xin
Long.
10) Fix locking in phy_is_started, from Heiner Kallweit.
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (54 commits)
net: ethernet: freescale: set FEC ethtool regs version
net: hns: Fix object reference leaks in hns_dsaf_roce_reset()
mm: page_alloc: fix ref bias in page_frag_alloc() for 1-byte allocs
net: phy: fix potential race in the phylib state machine
net: phy: don't use locking in phy_is_started
selftests: fix timestamping Makefile
net: dsa: bcm_sf2: potential array overflow in bcm_sf2_sw_suspend()
net: fix possible overflow in __sk_mem_raise_allocated()
dsa: mv88e6xxx: Ensure all pending interrupts are handled prior to exit
net: phy: fix interrupt handling in non-started states
sctp: set stream ext to NULL after freeing it in sctp_stream_outq_migrate
sctp: call gso_reset_checksum when computing checksum in sctp_gso_segment
net/mlx5e: XDP, fix redirect resources availability check
net/mlx5: Fix a compilation warning in events.c
net/mlx5: No command allowed when command interface is not ready
net/mlx5e: Fix NULL pointer derefernce in set channels error flow
netfilter: nft_compat: use-after-free when deleting targets
team: avoid complex list operations in team_nl_cmd_options_set()
net_sched: fix two more memory leaks in cls_tcindex
net_sched: fix a memory leak in cls_tcindex
...
|
|
The basic idea behind ->pagecnt_bias is: If we pre-allocate the maximum
number of references that we might need to create in the fastpath later,
the bump-allocation fastpath only has to modify the non-atomic bias value
that tracks the number of extra references we hold instead of the atomic
refcount. The maximum number of allocations we can serve (under the
assumption that no allocation is made with size 0) is nc->size, so that's
the bias used.
However, even when all memory in the allocation has been given away, a
reference to the page is still held; and in the `offset < 0` slowpath, the
page may be reused if everyone else has dropped their references.
This means that the necessary number of references is actually
`nc->size+1`.
Luckily, from a quick grep, it looks like the only path that can call
page_frag_alloc(fragsz=1) is TAP with the IFF_NAPI_FRAGS flag, which
requires CAP_NET_ADMIN in the init namespace and is only intended to be
used for kernel testing and fuzzing.
To test for this issue, put a `WARN_ON(page_ref_count(page) == 0)` in the
`offset < 0` path, below the virt_to_page() call, and then repeatedly call
writev() on a TAP device with IFF_TAP|IFF_NO_PI|IFF_NAPI_FRAGS|IFF_NAPI,
with a vector consisting of 15 elements containing 1 byte each.
Signed-off-by: Jann Horn <jannh@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
|
|
This reverts commit fe53ca54270a ("mm: use early_pfn_to_nid in
page_ext_init").
When booting a system with "page_owner=on",
start_kernel
page_ext_init
invoke_init_callbacks
init_section_page_ext
init_page_owner
init_early_allocated_pages
init_zones_in_node
init_pages_in_zone
lookup_page_ext
page_to_nid
The issue here is that page_to_nid() will not work since some page flags
have no node information until later in page_alloc_init_late() due to
DEFERRED_STRUCT_PAGE_INIT. Hence, it could trigger an out-of-bounds
access with an invalid nid.
UBSAN: Undefined behaviour in ./include/linux/mm.h:1104:50
index 7 is out of range for type 'zone [5]'
Also, kernel will panic since flags were poisoned earlier with,
CONFIG_DEBUG_VM_PGFLAGS=y
CONFIG_NODE_NOT_IN_PAGE_FLAGS=n
start_kernel
setup_arch
pagetable_init
paging_init
sparse_init
sparse_init_nid
memblock_alloc_try_nid_raw
It did not handle it well in init_pages_in_zone() which ends up calling
page_to_nid().
page:ffffea0004200000 is uninitialized and poisoned
raw: ffffffffffffffff ffffffffffffffff ffffffffffffffff ffffffffffffffff
raw: ffffffffffffffff ffffffffffffffff ffffffffffffffff ffffffffffffffff
page dumped because: VM_BUG_ON_PAGE(PagePoisoned(p))
page_owner info is not active (free page?)
kernel BUG at include/linux/mm.h:990!
RIP: 0010:init_page_owner+0x486/0x520
This means that assumptions behind commit fe53ca54270a ("mm: use
early_pfn_to_nid in page_ext_init") are incomplete. Therefore, revert
the commit for now. A proper way to move the page_owner initialization
to sooner is to hook into memmap initialization.
Link: http://lkml.kernel.org/r/20190115202812.75820-1-cai@lca.pw
Signed-off-by: Qian Cai <cai@lca.pw>
Acked-by: Michal Hocko <mhocko@kernel.org>
Cc: Pasha Tatashin <Pavel.Tatashin@microsoft.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Yang Shi <yang.shi@linaro.org>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
For dax pmd, pmd_trans_huge() returns false but pmd_huge() returns true
on x86. So the function works as long as hugetlb is configured.
However, dax doesn't depend on hugetlb.
Link: http://lkml.kernel.org/r/20190111034033.601-1-yuzhao@google.com
Signed-off-by: Yu Zhao <yuzhao@google.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Huang Ying <ying.huang@intel.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Keith Busch <keith.busch@intel.com>
Cc: "Michael S . Tsirkin" <mst@redhat.com>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Wei Yang <richard.weiyang@gmail.com>
Cc: Mike Rapoport <rppt@linux.ibm.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: "Kirill A . Shutemov" <kirill.shutemov@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
This reverts commit 172b06c32b9497 ("mm: slowly shrink slabs with a
relatively small number of objects").
This change changes the agressiveness of shrinker reclaim, causing small
cache and low priority reclaim to greatly increase scanning pressure on
small caches. As a result, light memory pressure has a disproportionate
affect on small caches, and causes large caches to be reclaimed much
faster than previously.
As a result, it greatly perturbs the delicate balance of the VFS caches
(dentry/inode vs file page cache) such that the inode/dentry caches are
reclaimed much, much faster than the page cache and this drives us into
several other caching imbalance related problems.
As such, this is a bad change and needs to be reverted.
[ Needs some massaging to retain the later seekless shrinker
modifications.]
Link: http://lkml.kernel.org/r/20190130041707.27750-3-david@fromorbit.com
Fixes: 172b06c32b9497 ("mm: slowly shrink slabs with a relatively small number of objects")
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Cc: Wolfgang Walter <linux@stwm.de>
Cc: Roman Gushchin <guro@fb.com>
Cc: Spock <dairinin@gmail.com>
Cc: Rik van Riel <riel@surriel.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
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We had a race in the old balloon compaction code before b1123ea6d3b3
("mm: balloon: use general non-lru movable page feature") refactored it
that became visible after backporting 195a8c43e93d ("virtio-balloon:
deflate via a page list") without the refactoring.
The bug existed from commit d6d86c0a7f8d ("mm/balloon_compaction:
redesign ballooned pages management") till b1123ea6d3b3 ("mm: balloon:
use general non-lru movable page feature"). d6d86c0a7f8d
("mm/balloon_compaction: redesign ballooned pages management") was
backported to 3.12, so the broken kernels are stable kernels [3.12 -
4.7].
There was a subtle race between dropping the page lock of the newpage in
__unmap_and_move() and checking for __is_movable_balloon_page(newpage).
Just after dropping this page lock, virtio-balloon could go ahead and
deflate the newpage, effectively dequeueing it and clearing PageBalloon,
in turn making __is_movable_balloon_page(newpage) fail.
This resulted in dropping the reference of the newpage via
putback_lru_page(newpage) instead of put_page(newpage), leading to
page->lru getting modified and a !LRU page ending up in the LRU lists.
With 195a8c43e93d ("virtio-balloon: deflate via a page list")
backported, one would suddenly get corrupted lists in
release_pages_balloon():
- WARNING: CPU: 13 PID: 6586 at lib/list_debug.c:59 __list_del_entry+0xa1/0xd0
- list_del corruption. prev->next should be ffffe253961090a0, but was dead000000000100
Nowadays this race is no longer possible, but it is hidden behind very
ugly handling of __ClearPageMovable() and __PageMovable().
__ClearPageMovable() will not make __PageMovable() fail, only
PageMovable(). So the new check (__PageMovable(newpage)) will still
hold even after newpage was dequeued by virtio-balloon.
If anybody would ever change that special handling, the BUG would be
introduced again. So instead, make it explicit and use the information
of the original isolated page before migration.
This patch can be backported fairly easy to stable kernels (in contrast
to the refactoring).
Link: http://lkml.kernel.org/r/20190129233217.10747-1-david@redhat.com
Fixes: d6d86c0a7f8d ("mm/balloon_compaction: redesign ballooned pages management")
Signed-off-by: David Hildenbrand <david@redhat.com>
Reported-by: Vratislav Bendel <vbendel@redhat.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Rafael Aquini <aquini@redhat.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Dominik Brodowski <linux@dominikbrodowski.net>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Vratislav Bendel <vbendel@redhat.com>
Cc: Rafael Aquini <aquini@redhat.com>
Cc: Konstantin Khlebnikov <k.khlebnikov@samsung.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: <stable@vger.kernel.org> [3.12 - 4.7]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Jan has noticed that we do double unlock on some failure paths when
offlining a page range. This is indeed the case when
test_pages_in_a_zone respp. start_isolate_page_range fail. This was an
omission when forward porting the debugging patch from an older kernel.
Fix the issue by dropping mem_hotplug_done from the failure condition
and keeping the single unlock in the catch all failure path.
Link: http://lkml.kernel.org/r/20190115120307.22768-1-mhocko@kernel.org
Fixes: 7960509329c2 ("mm, memory_hotplug: print reason for the offlining failure")
Signed-off-by: Michal Hocko <mhocko@suse.com>
Reported-by: Jan Kara <jack@suse.cz>
Reviewed-by: Jan Kara <jack@suse.cz>
Tested-by: Jan Kara <jack@suse.cz>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Currently memory_failure() is racy against process's exiting, which
results in kernel crash by null pointer dereference.
The root cause is that memory_failure() uses force_sig() to forcibly
kill asynchronous (meaning not in the current context) processes. As
discussed in thread https://lkml.org/lkml/2010/6/8/236 years ago for OOM
fixes, this is not a right thing to do. OOM solves this issue by using
do_send_sig_info() as done in commit d2d393099de2 ("signal:
oom_kill_task: use SEND_SIG_FORCED instead of force_sig()"), so this
patch is suggesting to do the same for hwpoison. do_send_sig_info()
properly accesses to siglock with lock_task_sighand(), so is free from
the reported race.
I confirmed that the reported bug reproduces with inserting some delay
in kill_procs(), and it never reproduces with this patch.
Note that memory_failure() can send another type of signal using
force_sig_mceerr(), and the reported race shouldn't happen on it because
force_sig_mceerr() is called only for synchronous processes (i.e.
BUS_MCEERR_AR happens only when some process accesses to the corrupted
memory.)
Link: http://lkml.kernel.org/r/20190116093046.GA29835@hori1.linux.bs1.fc.nec.co.jp
Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Reported-by: Jane Chu <jane.chu@oracle.com>
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Reviewed-by: William Kucharski <william.kucharski@oracle.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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When option CONFIG_KASAN is enabled toghether with ftrace, function
ftrace_graph_caller() gets in to a recursion, via functions
kasan_check_read() and kasan_check_write().
Breakpoint 2, ftrace_graph_caller () at ../arch/arm64/kernel/entry-ftrace.S:179
179 mcount_get_pc |
