Now BPF program will run with migration disabled, so it is safe to access this_cpu_inc_return(bpf_bprintf_nest_level). Fixes: d9c9e4db186a ("bpf: Factorize bpf_trace_printk and bpf_seq_printf") Signed-off-by: Tao Chen --- kernel/bpf/helpers.c | 3 --- 1 file changed, 3 deletions(-) diff --git a/kernel/bpf/helpers.c b/kernel/bpf/helpers.c index 6b4877e85a6..182886585d4 100644 --- a/kernel/bpf/helpers.c +++ b/kernel/bpf/helpers.c @@ -774,11 +774,9 @@ int bpf_try_get_buffers(struct bpf_bprintf_buffers **bufs) { int nest_level; - preempt_disable(); nest_level = this_cpu_inc_return(bpf_bprintf_nest_level); if (WARN_ON_ONCE(nest_level > MAX_BPRINTF_NEST_LEVEL)) { this_cpu_dec(bpf_bprintf_nest_level); - preempt_enable(); return -EBUSY; } *bufs = this_cpu_ptr(&bpf_bprintf_bufs[nest_level - 1]); @@ -791,7 +789,6 @@ void bpf_put_buffers(void) if (WARN_ON_ONCE(this_cpu_read(bpf_bprintf_nest_level) == 0)) return; this_cpu_dec(bpf_bprintf_nest_level); - preempt_enable(); } void bpf_bprintf_cleanup(struct bpf_bprintf_data *data) -- 2.48.1