diff options
| author | Muchun Song <songmuchun@bytedance.com> | 2020-08-11 18:30:32 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2020-08-12 10:57:55 -0700 |
| commit | 8ca39e6874f812a393bb66d9fdbb7598d5f0451c (patch) | |
| tree | 2bf84c48a229894833fecfaba7c832ff20fcde09 /mm/mempolicy.c | |
| parent | 90631e1dea55bfc14a8ee8c594aa136b243d4c88 (diff) | |
| download | linux-8ca39e6874f812a393bb66d9fdbb7598d5f0451c.tar.gz | |
mm/hugetlb: add mempolicy check in the reservation routine
In the reservation routine, we only check whether the cpuset meets the
memory allocation requirements. But we ignore the mempolicy of MPOL_BIND
case. If someone mmap hugetlb succeeds, but the subsequent memory
allocation may fail due to mempolicy restrictions and receives the SIGBUS
signal. This can be reproduced by the follow steps.
1) Compile the test case.
cd tools/testing/selftests/vm/
gcc map_hugetlb.c -o map_hugetlb
2) Pre-allocate huge pages. Suppose there are 2 numa nodes in the
system. Each node will pre-allocate one huge page.
echo 2 > /proc/sys/vm/nr_hugepages
3) Run test case(mmap 4MB). We receive the SIGBUS signal.
numactl --membind=3D0 ./map_hugetlb 4
With this patch applied, the mmap will fail in the step 3) and throw
"mmap: Cannot allocate memory".
[akpm@linux-foundation.org: include sched.h for `current']
Reported-by: Jianchao Guo <guojianchao@bytedance.com>
Suggested-by: Michal Hocko <mhocko@kernel.org>
Signed-off-by: Muchun Song <songmuchun@bytedance.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Michel Lespinasse <walken@google.com>
Cc: Baoquan He <bhe@redhat.com>
Link: http://lkml.kernel.org/r/20200728034938.14993-1-songmuchun@bytedance.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/mempolicy.c')
| -rw-r--r-- | mm/mempolicy.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/mm/mempolicy.c b/mm/mempolicy.c index b9e85d467352b9..7af44d7cdd114b 100644 --- a/mm/mempolicy.c +++ b/mm/mempolicy.c @@ -1890,7 +1890,7 @@ static int apply_policy_zone(struct mempolicy *policy, enum zone_type zone) * Return a nodemask representing a mempolicy for filtering nodes for * page allocation */ -static nodemask_t *policy_nodemask(gfp_t gfp, struct mempolicy *policy) +nodemask_t *policy_nodemask(gfp_t gfp, struct mempolicy *policy) { /* Lower zones don't get a nodemask applied for MPOL_BIND */ if (unlikely(policy->mode == MPOL_BIND) && |