From patchwork Tue Mar 18 08:35:45 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Andrea Terzolo X-Patchwork-Id: 14020581 X-Patchwork-Delegate: bpf@iogearbox.net Received: from mail-ed1-f42.google.com (mail-ed1-f42.google.com [209.85.208.42]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 50CAF1993B2 for ; Tue, 18 Mar 2025 08:35:59 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.208.42 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1742286961; cv=none; b=uMSqMDT9RNylfqcwp3pjHe0LXQFtn2zY9g4mSG9v4txKVC4WzPK9mp8Nn8ciOOebNBAWD9+fcUfGSjfW8S7ywbLsl5bn7hhGTGuL0g3LQlo5BAnr0Tg3bWEb+kOOERKTKvAdRQuHHXcI9RVJ/XtbcAcbRjWenIJ6OxpwuGkOTZs= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1742286961; c=relaxed/simple; bh=ofHQXrOci6TdGiHJcpZUGt8ernJPxhSeLSQt7wgr2zM=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=ei1kInhHvIAU8vYjF3cqC2tQ50jfswAc3dcKxOWr6R/pnV187qPfm9iZLJUQ4SVQTB3ktopcQZCfaaGlEB0COMblrwCVN9yf5Fbz/DU2DsoYOTVucZb9m0VYeECFkvw0Dnd7ipfiPvmEocXcnblXaOA4h+bfpXas60GjQKG5KcM= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com; spf=pass smtp.mailfrom=gmail.com; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b=IddWpiE0; arc=none smtp.client-ip=209.85.208.42 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gmail.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="IddWpiE0" Received: by mail-ed1-f42.google.com with SMTP id 4fb4d7f45d1cf-5e673822f76so8854775a12.2 for ; Tue, 18 Mar 2025 01:35:58 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1742286957; x=1742891757; darn=vger.kernel.org; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:from:to:cc:subject:date:message-id:reply-to; bh=q2VPnGRBzcv+Kb08eyb1zKUI7ekF3pqYETYwQknPA3E=; b=IddWpiE0+xUS3r8/NCJ2IuJ7Ar6RQ4KAinFE1vZOlYGX9QONVTMyLfuCXitt0V8WYW wm4SfPJAbuHbcMydy5/pKUsyRzPyTDnVNI9F8/o2vCyjSu6/l5MNn/LdgnfqJLl6viX/ m1N6arvgEDCrr4yrcw+cVfQ3tM/z8tLDY8DOQOGnTFPM7AIC6xKplCYYdtf7x5OWhyGZ dkYPt4gwPqL3owsQsJa9a8NAFqg228TapCCWOdjnotQEo0K6D+9gBcrnYq8Eq0zflH6M vVShafxb+Zk3rwWTg5VRTM2uo5hKAnn2lO6HIJqWGDbdzD2iE6Z5OsEe+IpJ5HBfxfzX /h2w== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1742286957; x=1742891757; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=q2VPnGRBzcv+Kb08eyb1zKUI7ekF3pqYETYwQknPA3E=; b=qazZR+8e6WyTDniToTLGdqT7bC6FKoogEVhvM4sOKRiQ4nMFskl3oPn0yLCEikBeqS A8fN7dmT0ysckyICefucczpgU1oYCjnYQSOPypvdDgtkazY7IUV4WbKCBWjLQ9YqU0/9 fJ3IdVZvS9SNb/jr94Zdyu/GaXGHa+nRXIDu6EPTbH0s4LoEbDfJUw44miF04K+yItr6 UyMm2aOsq4X7HS5CfrS24EVc7M9nQwsz+enV6dWb2z3uQGwIdko3vy2cG4HQezGlaGIC W0M+NAn7yIooY06sOephsxOr8BQivDV4k8RBo9msDS0PoIxCysVTrU32g3V1WUw04GSv WbVA== X-Gm-Message-State: AOJu0YzndoOTH0QKbsNJWZO2y+ERvkeaPjp/B7uy005qVBqTgQP0amso fLtJQl3DX5zVLSTRGto4uBPaCqINfPXbg/KxQ31sKuvbc+mSnJQNP2O7WaeA X-Gm-Gg: ASbGncvJ+9woundqD0Htc9ARs8X6BL2TNarRNBnm/mqrzv+vo5yAehr4CsKUwx6MevT B9xcOHjbn8rmuNQnXe+YjZIyLCEPuPPP6J9KvxcKi6DDMwomVbCyRkWjCsrL1h3ltKKHtRUwJU2 epV2NpZdsB9u0bc5JVPTd5ASVX5oCzTFsDrBhAhnoZB/70ojRmB9XQuzGt6Dpv1rVKlCgKoQJBm TT86+v1+Yhux63YcDMdF6UbmQwN+WoW8LYDgHsRrEp4dAXPbMTPfz8kxnsTiApgpYBRj68IQmNp 2aQcvMrVlB5roKympUqLnQ3AG6/b31Y24u6N6Ft803qkXIYsscgX0EdP X-Google-Smtp-Source: AGHT+IEJhK2yOsxTuXsF2I1d/sA9sGkjqOqTBtLRa9tdImPoqoB64Bik/0Tf1sSH/i/OrDAxEoARkA== X-Received: by 2002:a05:6402:1d53:b0:5e7:88d8:30a6 with SMTP id 4fb4d7f45d1cf-5e8a0421852mr13377090a12.20.1742286956530; Tue, 18 Mar 2025 01:35:56 -0700 (PDT) Received: from andrea-terzolo.. ([151.33.82.208]) by smtp.gmail.com with ESMTPSA id 4fb4d7f45d1cf-5e816977a5fsm7194853a12.32.2025.03.18.01.35.54 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 18 Mar 2025 01:35:55 -0700 (PDT) From: Andrea Terzolo To: bpf@vger.kernel.org Cc: Andrea Terzolo , Alexei Starovoitov , Daniel Borkmann , John Fastabend , Andrii Nakryiko , Martin KaFai Lau , Eduard Zingerman , Song Liu , Yonghong Song , KP Singh , Stanislav Fomichev , Hao Luo , Jiri Olsa , Shung-Hsi Yu Subject: [PATCH bpf] bpf: clarify a misleading verifier error message Date: Tue, 18 Mar 2025 09:35:45 +0100 Message-ID: <20250318083551.8192-1-andreaterzolo3@gmail.com> X-Mailer: git-send-email 2.43.0 Precedence: bulk X-Mailing-List: bpf@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Patchwork-Delegate: bpf@iogearbox.net The current verifier error message states that tail_calls are not allowed in non-JITed programs with BPF-to-BPF calls. While this is accurate, it is not the only scenario where this restriction applies. Some architectures do not support this feature combination even when programs are JITed. This update improves the error message to better reflect these limitations. Suggested-by: Shung-Hsi Yu Signed-off-by: Andrea Terzolo Acked-by: Shung-Hsi Yu --- kernel/bpf/verifier.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index 3303a3605..2e94fe5ea 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -9887,7 +9887,7 @@ static int check_map_func_compatibility(struct bpf_verifier_env *env, if (map->map_type != BPF_MAP_TYPE_PROG_ARRAY) goto error; if (env->subprog_cnt > 1 && !allow_tail_call_in_subprogs(env)) { - verbose(env, "tail_calls are not allowed in non-JITed programs with bpf-to-bpf calls\n"); + verbose(env, "mixing of tail_calls and bpf-to-bpf calls not supported\n"); return -EINVAL; } break;