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authorKonstantin Khlebnikov <khlebnikov@yandex-team.ru>2019-02-27 11:10:18 +0300
committerIngo Molnar <mingo@kernel.org>2019-04-19 13:42:10 +0200
commit5b61d50ab4ef590f5e1d4df15cd2cea5f5715308 (patch)
tree5ff78a0cea29abcde6e7bc6f7c9e8e1f772a071a /kernel/sched
parent1a010e29cfa00fee2888fd2fd4983f848cbafb58 (diff)
downloadlinux-5b61d50ab4ef590f5e1d4df15cd2cea5f5715308.tar.bz2
sched/core: Handle overflow in cpu_shares_write_u64
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>
Diffstat (limited to 'kernel/sched')
-rw-r--r--kernel/sched/core.c2
1 files changed, 2 insertions, 0 deletions
diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index fb09eaad1d3a..685b1541ce51 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -6507,6 +6507,8 @@ 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));
}