From patchwork Wed Feb 21 16:25:19 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Benjamin Tissoires X-Patchwork-Id: 13565933 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id D13F08062A; Wed, 21 Feb 2024 16:25:37 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1708532737; cv=none; b=sveNfKGLBCoDdsZN7MOCJek89HmuYNBON7keO+g2A0P/R9Rl5wYsij17+9iMarpkmg9eqcaJ9ruBTcpIRkom63wCiBzc+ntVc7meUNjSu6Fevl9gAoALNKD3BGW1Su9WaVF2QmidNFGpSZy7DU+VHfeNrNf04KaPyCY1dRmZISI= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1708532737; c=relaxed/simple; bh=ifZFLSAYIFkAKgWtCvrWc7FBsIzi3tPzHayMgfZ0rSU=; 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a=ed25519-sha256; t=1708532719; l=1797; i=bentiss@kernel.org; s=20230215; h=from:subject:message-id; bh=ifZFLSAYIFkAKgWtCvrWc7FBsIzi3tPzHayMgfZ0rSU=; b=JIpXu3g0QunAN4Krqvk/yZ3ph5YehKnA1pxkpJWLimDr+7xLD4HesIWBl5fi/gxLdz+IaKjQS 6HWbJS3t48jANwXHML823DEwFy3apcxCIjwCzfSeuTPrRLWd5Q92NG/ X-Developer-Key: i=bentiss@kernel.org; a=ed25519; pk=7D1DyAVh6ajCkuUTudt/chMuXWIJHlv2qCsRkIizvFw= Currently we have a special case for BPF_FUNC_timer_set_callback, let's introduce a helper we can extend for the kfunc that will come in a later patch Signed-off-by: Benjamin Tissoires --- new in v3 --- kernel/bpf/verifier.c | 11 +++++++---- 1 file changed, 7 insertions(+), 4 deletions(-) diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index 7a4b19bea2ac..f81c799b2c80 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -528,6 +528,11 @@ static bool is_sync_callback_calling_insn(struct bpf_insn *insn) (bpf_pseudo_kfunc_call(insn) && is_sync_callback_calling_kfunc(insn->imm)); } +static bool is_async_callback_calling_insn(struct bpf_insn *insn) +{ + return (bpf_helper_call(insn) && is_async_callback_calling_function(insn->imm)); +} + static bool is_storage_get_function(enum bpf_func_id func_id) { return func_id == BPF_FUNC_sk_storage_get || @@ -9445,9 +9450,7 @@ static int push_callback_call(struct bpf_verifier_env *env, struct bpf_insn *ins return -EFAULT; } - if (insn->code == (BPF_JMP | BPF_CALL) && - insn->src_reg == 0 && - insn->imm == BPF_FUNC_timer_set_callback) { + if (is_async_callback_calling_insn(insn)) { struct bpf_verifier_state *async_cb; /* there is no real recursion here. timer callbacks are async */ @@ -15588,7 +15591,7 @@ static int visit_insn(int t, struct bpf_verifier_env *env) return DONE_EXPLORING; case BPF_CALL: - if (insn->src_reg == 0 && insn->imm == BPF_FUNC_timer_set_callback) + if (is_async_callback_calling_insn(insn)) /* Mark this call insn as a prune point to trigger * is_state_visited() check before call itself is * processed by __check_func_call(). Otherwise new