From patchwork Fri Feb 28 19:46:53 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ihor Solodrai X-Patchwork-Id: 13996991 Received: from out-182.mta0.migadu.com (out-182.mta0.migadu.com [91.218.175.182]) (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 52C4D1C5D6F for ; Fri, 28 Feb 2025 19:47:14 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=91.218.175.182 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1740772036; cv=none; b=g4lpsnCsZIQ2+BlMltnnlrHNTDTgr6w4TsxamBciC+kKLMepHuhT638/vd3cqj/4ywVZi3xup2oaUMmxoZaJJJaGWZ3zZmwO0oneBRS05/FIHh4ssY/R59/j5GCp7WJcs371AlKtbvIxQTVlzsqLFy3KOjLJd/Zh66nz9nd/LSs= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1740772036; c=relaxed/simple; bh=r6r4dSlFapZUVjswghkEX+7sIhVJtAX38qeiU9NIrcM=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=s6VsKwVhHdUEjnzsD2wju4uSVDg2WkmmkJjujZJQn4qxjT8tIjwYq6rtdEll9O1R5pDBTbdRIepJhL6Agn3of/UBEfkbmFLhhEOO6OvV5cjNGPG1VQlnTSmaJm/yhrVl2flQ8IXOPFWVxtAK+k2BVJkMinkq3xPBXU8ZSmCfbpw= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev; spf=pass smtp.mailfrom=linux.dev; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b=Fubt9Xgq; arc=none smtp.client-ip=91.218.175.182 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.dev Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b="Fubt9Xgq" X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1740772032; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=7ebJ0unhVkfowMF5mvxUvLPwb4cKdQqQNwraw6G5iG8=; b=Fubt9XgqPSf3LINrUruKdNLSHVNmkLD1Ck+EcogtNYsrtkY6gpsDzfc5ZV+wfPh4mhEJEc 9ibMQ70HW05cVovxxoMK9FoYSlFgQfVoeB16OSqKE/Jg6vckYxV9gxkTUWhHFANXwiRtSl 36oKOlIkcRVh/p1Hz2cEAmK+juPYauw= From: Ihor Solodrai To: dwarves@vger.kernel.org, bpf@vger.kernel.org Cc: acme@kernel.org, alan.maguire@oracle.com, ast@kernel.org, andrii@kernel.org, eddyz87@gmail.com, mykolal@fb.com, kernel-team@meta.com Subject: [PATCH dwarves v4 5/6] pahole: introduce --btf_feature=attributes Date: Fri, 28 Feb 2025 11:46:53 -0800 Message-ID: <20250228194654.1022535-6-ihor.solodrai@linux.dev> In-Reply-To: <20250228194654.1022535-1-ihor.solodrai@linux.dev> References: <20250228194654.1022535-1-ihor.solodrai@linux.dev> Precedence: bulk X-Mailing-List: bpf@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Migadu-Flow: FLOW_OUT Add a feature flag "attributes" (default: false) controlling whether pahole is allowed to generate BTF attributes: type tags and decl tags with kind_flag = 1. This is necessary for backward compatibility, as BPF verifier does not recognize tags with kind_flag = 1 prior to (at least) 6.14-rc1 [1]. [1] https://lore.kernel.org/bpf/20250130201239.1429648-1-ihor.solodrai@linux.dev/ Signed-off-by: Ihor Solodrai Reviewed-by: Alan Maguire Reviewed-by: Jiri Olsa Acked-by: Eduard Zingerman --- btf_encoder.c | 6 ++++-- dwarves.h | 1 + pahole.c | 9 +++++++++ 3 files changed, 14 insertions(+), 2 deletions(-) diff --git a/btf_encoder.c b/btf_encoder.c index 991aba6..b380764 100644 --- a/btf_encoder.c +++ b/btf_encoder.c @@ -137,7 +137,8 @@ struct btf_encoder { gen_floats, skip_encoding_decl_tag, tag_kfuncs, - gen_distilled_base; + gen_distilled_base, + encode_attributes; uint32_t array_index_id; struct elf_secinfo *secinfo; size_t seccnt; @@ -812,7 +813,7 @@ static int32_t btf_encoder__add_func_proto(struct btf_encoder *encoder, struct f assert(ftype != NULL || state != NULL); - if (is_kfunc_state(state) && encoder->tag_kfuncs) + if (is_kfunc_state(state) && encoder->tag_kfuncs && encoder->encode_attributes) if (btf__add_bpf_arena_type_tags(encoder->btf, state) < 0) return -1; @@ -2405,6 +2406,7 @@ struct btf_encoder *btf_encoder__new(struct cu *cu, const char *detached_filenam encoder->skip_encoding_decl_tag = conf_load->skip_encoding_btf_decl_tag; encoder->tag_kfuncs = conf_load->btf_decl_tag_kfuncs; encoder->gen_distilled_base = conf_load->btf_gen_distilled_base; + encoder->encode_attributes = conf_load->btf_attributes; encoder->verbose = verbose; encoder->has_index_type = false; encoder->need_index_type = false; diff --git a/dwarves.h b/dwarves.h index 4202dfb..36c6898 100644 --- a/dwarves.h +++ b/dwarves.h @@ -99,6 +99,7 @@ struct conf_load { bool reproducible_build; bool btf_decl_tag_kfuncs; bool btf_gen_distilled_base; + bool btf_attributes; uint8_t hashtable_bits; uint8_t max_hashtable_bits; uint16_t kabi_prefix_len; diff --git a/pahole.c b/pahole.c index 09aed1c..848827e 100644 --- a/pahole.c +++ b/pahole.c @@ -1152,6 +1152,7 @@ ARGP_PROGRAM_VERSION_HOOK_DEF = dwarves_print_version; #define ARG_padding_ge 347 #define ARG_padding 348 #define ARGP_with_embedded_flexible_array 349 +#define ARGP_btf_attributes 350 /* --btf_features=feature1[,feature2,..] allows us to specify * a list of requested BTF features or "default" to enable all default @@ -1208,6 +1209,7 @@ struct btf_feature { BTF_NON_DEFAULT_FEATURE(reproducible_build, reproducible_build, false), BTF_NON_DEFAULT_FEATURE(distilled_base, btf_gen_distilled_base, false), BTF_NON_DEFAULT_FEATURE(global_var, encode_btf_global_vars, false), + BTF_NON_DEFAULT_FEATURE(attributes, btf_attributes, false), }; #define BTF_MAX_FEATURE_STR 1024 @@ -1783,6 +1785,11 @@ static const struct argp_option pahole__options[] = { .key = ARGP_running_kernel_vmlinux, .doc = "Search for, possibly getting from a debuginfo server, a vmlinux matching the running kernel build-id (from /sys/kernel/notes)" }, + { + .name = "btf_attributes", + .key = ARGP_btf_attributes, + .doc = "Allow generation of attributes in BTF. Attributes are the type tags and decl tags with the kind_flag set to 1.", + }, { .name = NULL, } @@ -1977,6 +1984,8 @@ static error_t pahole__options_parser(int key, char *arg, show_supported_btf_features(stdout); exit(0); case ARGP_btf_features_strict: parse_btf_features(arg, true); break; + case ARGP_btf_attributes: + conf_load.btf_attributes = true; break; default: return ARGP_ERR_UNKNOWN; }