diff options
| author | Konstantin Khlebnikov <khlebnikov@yandex-team.ru> | 2019-02-27 11:10:18 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2019-05-31 06:47:26 -0700 |
| commit | e58b6d6a67b409696e81f183d610dcfb6cc758ec (patch) | |
| tree | 6a953b4b06b8a611a132331d6e3a80eb484ebbd5 /kernel | |
| parent | 3c06c178cf046aa67f10d419ed7a50353bc47297 (diff) | |
sched/core: Handle overflow in cpu_shares_write_u64
[ Upstream commit 5b61d50ab4ef590f5e1d4df15cd2cea5f5715308 ]
Bit shift in scale_load() could overflow shares. This patch saturates
it to MAX_SHARES like following sched_group_set_shares().
Example:
# echo 9223372036854776832 > cpu.shares
# cat cpu.shares
Before patch: 1024
After pattch: 262144
Signed-off-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/155125501891.293431.3345233332801109696.stgit@buzz
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/sched/core.c | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/kernel/sched/core.c b/kernel/sched/core.c index 2464a242d6c9..b3ff73d6a4c2 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -6380,6 +6380,8 @@ static void cpu_cgroup_attach(struct cgroup_taskset *tset) static int cpu_shares_write_u64(struct cgroup_subsys_state *css, struct cftype *cftype, u64 shareval) { + if (shareval > scale_load_down(ULONG_MAX)) + shareval = MAX_SHARES; return sched_group_set_shares(css_tg(css), scale_load(shareval)); } |