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authorAlexei Starovoitov <ast@kernel.org>2021-02-09 19:36:27 -0800
committerDaniel Borkmann <daniel@iogearbox.net>2021-02-11 16:18:55 +0100
commit031d6e02ddbb8dea747c1abb697d556901f07dd4 (patch)
tree2a4acbda0c22f3a2df375ed31a4123e5f2bd761a /kernel/bpf/trampoline.c
parent700d4796ef59f5faf240d307839bd419e2b6bdff (diff)
downloadlinux-031d6e02ddbb8dea747c1abb697d556901f07dd4.tar.gz
bpf: Run sleepable programs with migration disabled
In older non-RT kernels migrate_disable() was the same as preempt_disable().
Since commit 74d862b682f5 ("sched: Make migrate_disable/enable() independent of RT")
migrate_disable() is real and doesn't prevent sleeping.

Running sleepable programs with migration disabled allows to add support for
program stats and per-cpu maps later.

Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: KP Singh <kpsingh@kernel.org>
Link: https://lore.kernel.org/bpf/20210210033634.62081-3-alexei.starovoitov@gmail.com
Diffstat (limited to 'kernel/bpf/trampoline.c')
-rw-r--r--kernel/bpf/trampoline.c2
1 files changed, 2 insertions, 0 deletions
diff --git a/kernel/bpf/trampoline.c b/kernel/bpf/trampoline.c
index 5be3beeedd74..89fc849ba271 100644
--- a/kernel/bpf/trampoline.c
+++ b/kernel/bpf/trampoline.c
@@ -425,11 +425,13 @@ void notrace __bpf_prog_exit(struct bpf_prog *prog, u64 start)
 void notrace __bpf_prog_enter_sleepable(void)
 {
 	rcu_read_lock_trace();
+	migrate_disable();
 	might_fault();
 }
 
 void notrace __bpf_prog_exit_sleepable(void)
 {
+	migrate_enable();
 	rcu_read_unlock_trace();
 }