From 957e1a4e35c79e3910a4f9d6d84fcefb321d966d Mon Sep 17 00:00:00 2001 From: David Miller Date: Mon, 24 Feb 2020 15:01:46 +0100 Subject: [PATCH] UPSTREAM: bpf: Use migrate_disable/enable in array macros and cgroup/lirc code. Replace the preemption disable/enable with migrate_disable/enable() to reflect the actual requirement and to allow PREEMPT_RT to substitute it with an actual migration disable mechanism which does not disable preemption. Including the code paths that go via __bpf_prog_run_save_cb(). Change-Id: I6501b529705776fa8ca2618286f6abcd320fc66f Signed-off-by: David S. Miller Signed-off-by: Thomas Gleixner Signed-off-by: Alexei Starovoitov Link: https://lore.kernel.org/bpf/20200224145643.998293311@linutronix.de --- include/linux/bpf.h | 8 ++++---- include/linux/filter.h | 5 +++-- 2 files changed, 7 insertions(+), 6 deletions(-) diff --git a/include/linux/bpf.h b/include/linux/bpf.h index 1bc292768391..d3a1ddc55cc5 100644 --- a/include/linux/bpf.h +++ b/include/linux/bpf.h @@ -885,7 +885,7 @@ int bpf_prog_array_copy(struct bpf_prog_array *old_array, struct bpf_prog *_prog; \ struct bpf_prog_array *_array; \ u32 _ret = 1; \ - preempt_disable(); \ + migrate_disable(); \ rcu_read_lock(); \ _array = rcu_dereference(array); \ if (unlikely(check_non_null && !_array))\ @@ -899,7 +899,7 @@ int bpf_prog_array_copy(struct bpf_prog_array *old_array, } \ _out: \ rcu_read_unlock(); \ - preempt_enable(); \ + migrate_enable(); \ _ret; \ }) @@ -933,7 +933,7 @@ _out: \ u32 ret; \ u32 _ret = 1; \ u32 _cn = 0; \ - preempt_disable(); \ + migrate_disable(); \ rcu_read_lock(); \ _array = rcu_dereference(array); \ _item = &_array->items[0]; \ @@ -945,7 +945,7 @@ _out: \ _item++; \ } \ rcu_read_unlock(); \ - preempt_enable(); \ + migrate_enable(); \ if (_ret) \ _ret = (_cn ? NET_XMIT_CN : NET_XMIT_SUCCESS); \ else \ diff --git a/include/linux/filter.h b/include/linux/filter.h index 5423e92961e1..74ec6c91a7cc 100644 --- a/include/linux/filter.h +++ b/include/linux/filter.h @@ -733,6 +733,7 @@ static inline u8 *bpf_skb_cb(struct sk_buff *skb) return qdisc_skb_cb(skb)->data; } +/* Must be invoked with migration disabled */ static inline u32 __bpf_prog_run_save_cb(const struct bpf_prog *prog, struct sk_buff *skb) { @@ -758,9 +759,9 @@ static inline u32 bpf_prog_run_save_cb(const struct bpf_prog *prog, { u32 res; - preempt_disable(); + migrate_disable(); res = __bpf_prog_run_save_cb(prog, skb); - preempt_enable(); + migrate_enable(); return res; }