From 02ad05965491ca72034327d47da6cb25f3a92603 Mon Sep 17 00:00:00 2001 From: David Miller Date: Mon, 24 Feb 2020 15:01:45 +0100 Subject: [PATCH] bpf: Use migrate_disable/enabe() in trampoline code. Instead of preemption disable/enable to reflect the purpose. This allows PREEMPT_RT to substitute it with an actual migration disable implementation. On non RT kernels this is still mapped to preempt_disable/enable(). Signed-off-by: David S. Miller Signed-off-by: Thomas Gleixner Signed-off-by: Alexei Starovoitov Link: https://lore.kernel.org/bpf/20200224145643.891428873@linutronix.de --- kernel/bpf/trampoline.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/kernel/bpf/trampoline.c b/kernel/bpf/trampoline.c index 6b264a9..704fa78 100644 --- a/kernel/bpf/trampoline.c +++ b/kernel/bpf/trampoline.c @@ -367,8 +367,9 @@ out: mutex_unlock(&trampoline_mutex); } -/* The logic is similar to BPF_PROG_RUN, but with explicit rcu and preempt that - * are needed for trampoline. The macro is split into +/* The logic is similar to BPF_PROG_RUN, but with an explicit + * rcu_read_lock() and migrate_disable() which are required + * for the trampoline. The macro is split into * call _bpf_prog_enter * call prog->bpf_func * call __bpf_prog_exit @@ -378,7 +379,7 @@ u64 notrace __bpf_prog_enter(void) u64 start = 0; rcu_read_lock(); - preempt_disable(); + migrate_disable(); if (static_branch_unlikely(&bpf_stats_enabled_key)) start = sched_clock(); return start; @@ -401,7 +402,7 @@ void notrace __bpf_prog_exit(struct bpf_prog *prog, u64 start) stats->nsecs += sched_clock() - start; u64_stats_update_end(&stats->syncp); } - preempt_enable(); + migrate_enable(); rcu_read_unlock(); } -- 2.7.4