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author | David S. Miller <davem@davemloft.net> | 2020-07-11 00:46:00 -0700 |
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committer | David S. Miller <davem@davemloft.net> | 2020-07-11 00:46:00 -0700 |
commit | 71930d61025e7d0254f3c682cb1b5242e0499cf3 (patch) | |
tree | 43b642f15d33ae6ba08a31ddf2d50e2915868a5e /mm/compaction.c | |
parent | a594920f8747fa032c784c3660d6cd5a8ab291f8 (diff) | |
parent | 1df0d8960499e58963fd6c8ac75e544f2b417b29 (diff) | |
download | linux-71930d61025e7d0254f3c682cb1b5242e0499cf3.tar.bz2 |
Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
All conflicts seemed rather trivial, with some guidance from
Saeed Mameed on the tc_ct.c one.
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'mm/compaction.c')
-rw-r--r-- | mm/compaction.c | 17 |
1 files changed, 14 insertions, 3 deletions
diff --git a/mm/compaction.c b/mm/compaction.c index fd988b7e5f2b..86375605faa9 100644 --- a/mm/compaction.c +++ b/mm/compaction.c @@ -2316,15 +2316,26 @@ static enum compact_result compact_zone_order(struct zone *zone, int order, .page = NULL, }; - current->capture_control = &capc; + /* + * Make sure the structs are really initialized before we expose the + * capture control, in case we are interrupted and the interrupt handler + * frees a page. + */ + barrier(); + WRITE_ONCE(current->capture_control, &capc); ret = compact_zone(&cc, &capc); VM_BUG_ON(!list_empty(&cc.freepages)); VM_BUG_ON(!list_empty(&cc.migratepages)); - *capture = capc.page; - current->capture_control = NULL; + /* + * Make sure we hide capture control first before we read the captured + * page pointer, otherwise an interrupt could free and capture a page + * and we would leak it. + */ + WRITE_ONCE(current->capture_control, NULL); + *capture = READ_ONCE(capc.page); return ret; } |