diff options
| author | Bhupesh Sharma <bhsharma@redhat.com> | 2020-07-23 21:15:21 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2020-07-24 12:42:41 -0700 |
| commit | 82ff165cd35110d4e380b55927bbd74dcb564998 (patch) | |
| tree | 379953d277a483141e87c1eaefced31ae8946148 /mm/memcontrol.c | |
| parent | 45779b036d3d2870633443a9f9bd03c177befbf5 (diff) | |
mm/memcontrol: fix OOPS inside mem_cgroup_get_nr_swap_pages()
Prabhakar reported an OOPS inside mem_cgroup_get_nr_swap_pages()
function in a corner case seen on some arm64 boards when kdump kernel
runs with "cgroup_disable=memory" passed to the kdump kernel via
bootargs.
The root-cause behind the same is that currently mem_cgroup_swap_init()
function is implemented as a subsys_initcall() call instead of a
core_initcall(), this means 'cgroup_memory_noswap' still remains set to
the default value (false) even when memcg is disabled via
"cgroup_disable=memory" boot parameter.
This may result in premature OOPS inside mem_cgroup_get_nr_swap_pages()
function in corner cases:
Unable to handle kernel NULL pointer dereference at virtual address 0000000000000188
Mem abort info:
ESR = 0x96000006
EC = 0x25: DABT (current EL), IL = 32 bits
SET = 0, FnV = 0
EA = 0, S1PTW = 0
Data abort info:
ISV = 0, ISS = 0x00000006
CM = 0, WnR = 0
[0000000000000188] user address but active_mm is swapper
Internal error: Oops: 96000006 [#1] SMP
Modules linked in:
<..snip..>
Call trace:
mem_cgroup_get_nr_swap_pages+0x9c/0xf4
shrink_lruvec+0x404/0x4f8
shrink_node+0x1a8/0x688
do_try_to_free_pages+0xe8/0x448
try_to_free_pages+0x110/0x230
__alloc_pages_slowpath.constprop.106+0x2b8/0xb48
__alloc_pages_nodemask+0x2ac/0x2f8
alloc_page_interleave+0x20/0x90
alloc_pages_current+0xdc/0xf8
atomic_pool_expand+0x60/0x210
__dma_atomic_pool_init+0x50/0xa4
dma_atomic_pool_init+0xac/0x158
do_one_initcall+0x50/0x218
kernel_init_freeable+0x22c/0x2d0
kernel_init+0x18/0x110
ret_from_fork+0x10/0x18
Code: aa1403e3 91106000 97f82a27 14000011 (f940c663)
---[ end trace 9795948475817de4 ]---
Kernel panic - not syncing: Fatal exception
Rebooting in 10 seconds..
Fixes: eccb52e78809 ("mm: memcontrol: prepare swap controller setup for integration")
Reported-by: Prabhakar Kushwaha <pkushwaha@marvell.com>
Signed-off-by: Bhupesh Sharma <bhsharma@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: James Morse <james.morse@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Link: http://lkml.kernel.org/r/1593641660-13254-2-git-send-email-bhsharma@redhat.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/memcontrol.c')
| -rw-r--r-- | mm/memcontrol.c | 9 |
1 files changed, 8 insertions, 1 deletions
diff --git a/mm/memcontrol.c b/mm/memcontrol.c index 19622328e4b5..c75c4face02e 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -7186,6 +7186,13 @@ static struct cftype memsw_files[] = { { }, /* terminate */ }; +/* + * If mem_cgroup_swap_init() is implemented as a subsys_initcall() + * instead of a core_initcall(), this could mean cgroup_memory_noswap still + * remains set to false even when memcg is disabled via "cgroup_disable=memory" + * boot parameter. This may result in premature OOPS inside + * mem_cgroup_get_nr_swap_pages() function in corner cases. + */ static int __init mem_cgroup_swap_init(void) { /* No memory control -> no swap control */ @@ -7200,6 +7207,6 @@ static int __init mem_cgroup_swap_init(void) return 0; } -subsys_initcall(mem_cgroup_swap_init); +core_initcall(mem_cgroup_swap_init); #endif /* CONFIG_MEMCG_SWAP */ |