Commit 031d6e02 authored by Alexei Starovoitov's avatar Alexei Starovoitov Committed by Daniel Borkmann
Browse files

bpf: Run sleepable programs with migration disabled 



In older non-RT kernels migrate_disable() was the same as preempt_disable().
Since commit 74d862b6 ("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: default avatarAlexei Starovoitov <ast@kernel.org>
Signed-off-by: default avatarDaniel Borkmann <daniel@iogearbox.net>
Acked-by: default avatarKP Singh <kpsingh@kernel.org>
Link: https://lore.kernel.org/bpf/20210210033634.62081-3-alexei.starovoitov@gmail.com
parent 700d4796

kernel/bpf/trampoline.c

+2 −0
Original line number Diff line number Diff line
@@ -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();

}