From c941ce9c282cc606e6517356fcc186a9da2b4ab9 Mon Sep 17 00:00:00 2001 From: Quentin Monnet Date: Sun, 7 Oct 2018 12:56:47 +0100 Subject: bpf: add verifier callback to get stack usage info for offloaded progs In preparation for BPF-to-BPF calls in offloaded programs, add a new function attribute to the struct bpf_prog_offload_ops so that drivers supporting eBPF offload can hook at the end of program verification, and potentially extract information collected by the verifier. Implement a minimal callback (returning 0) in the drivers providing the structs, namely netdevsim and nfp. This will be useful in the nfp driver, in later commits, to extract the number of subprograms as well as the stack depth for those subprograms. Signed-off-by: Quentin Monnet Reviewed-by: Jiong Wang Reviewed-by: Jakub Kicinski Signed-off-by: Daniel Borkmann --- kernel/bpf/offload.c | 18 ++++++++++++++++++ kernel/bpf/verifier.c | 3 +++ 2 files changed, 21 insertions(+) (limited to 'kernel/bpf') diff --git a/kernel/bpf/offload.c b/kernel/bpf/offload.c index 177a52436394..8e93c47f0779 100644 --- a/kernel/bpf/offload.c +++ b/kernel/bpf/offload.c @@ -172,6 +172,24 @@ int bpf_prog_offload_verify_insn(struct bpf_verifier_env *env, return ret; } +int bpf_prog_offload_finalize(struct bpf_verifier_env *env) +{ + struct bpf_prog_offload *offload; + int ret = -ENODEV; + + down_read(&bpf_devs_lock); + offload = env->prog->aux->offload; + if (offload) { + if (offload->dev_ops->finalize) + ret = offload->dev_ops->finalize(env); + else + ret = 0; + } + up_read(&bpf_devs_lock); + + return ret; +} + static void __bpf_prog_offload_destroy(struct bpf_prog *prog) { struct bpf_prog_offload *offload = prog->aux->offload; diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index 73c81bef6ae8..a0454cb299ba 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -6309,6 +6309,9 @@ int bpf_check(struct bpf_prog **prog, union bpf_attr *attr) env->cur_state = NULL; } + if (ret == 0 && bpf_prog_is_dev_bound(env->prog->aux)) + ret = bpf_prog_offload_finalize(env); + skip_full_check: while (!pop_stack(env, NULL, NULL)); free_states(env); -- cgit