From patchwork Thu Oct 5 22:03:23 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ian Rogers X-Patchwork-Id: 13410838 X-Patchwork-Delegate: bpf@iogearbox.net Received: from lindbergh.monkeyblade.net (lindbergh.monkeyblade.net [23.128.96.19]) (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 DECF441E45 for ; Thu, 5 Oct 2023 22:03:30 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="hbw1RH/r" Received: from mail-yb1-xb49.google.com (mail-yb1-xb49.google.com [IPv6:2607:f8b0:4864:20::b49]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 4BC9595 for ; Thu, 5 Oct 2023 15:03:29 -0700 (PDT) Received: by mail-yb1-xb49.google.com with SMTP id 3f1490d57ef6-d84acda47aeso2035649276.3 for ; Thu, 05 Oct 2023 15:03:29 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1696543408; x=1697148208; darn=vger.kernel.org; h=cc:to:from:subject:mime-version:message-id:date:from:to:cc:subject :date:message-id:reply-to; bh=l3o6wyBSROZp99HOssTXqpXKVsTtNmt9jgf0aZMxwy0=; b=hbw1RH/rDSDbT8w7/RCxWggqTGsq2S5bgAEQ27PmhmbHFtuQ+/zb3EtJB9p6sIbf/o K6XKaIHZ6lksGCZnnuuPIc47XUl2jZBmuLFqmoaJAkEGy2OtlSmInG/OiVAfoWyAzFs/ B6b4LktvD+4Msv8u0ij8yqEcgHJpvr5SOr20Yz2xaDQHIPsHoF9MyDpAfmFzUJMWiMqz jnbSeLm0AmsyTB9037GyffjDy9Fu4wAfTi0zW/VjBs4FlD4fmuKbi5rgrywINne650oO 6ePP8B823zkmdiNmtCZCmAUEG3tooHIgb2SveK6GaiJaJFveY1ju0XQnuE2C+YlVfJnb oaTw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1696543408; x=1697148208; h=cc:to:from:subject:mime-version:message-id:date:x-gm-message-state :from:to:cc:subject:date:message-id:reply-to; bh=l3o6wyBSROZp99HOssTXqpXKVsTtNmt9jgf0aZMxwy0=; b=cj0PdDHGluxWGfXxg0rJ6VVIkjEyaG1ixecgPDuQDzsJujX1OocXlotIjNgMMnzh00 iEGCgtSpmgeWzRqDnVgh+zzTHaOHEvgcYugjWzszCFlfMVWl4ByMUcSHIMauWPBzkalv lppJSKCa5sBXDn03himqFSE7JNWXnXdZVaDfSXQq7BkbiIPAPpD56iS/G/vJvn1bCkNg q30HB+/Ds9oi8yPgGQMAujQ7QeKpLPO/4r+Mo9E9odNLcI9p1Eg7e1gzdyK3YZETHtFk 1ujFjmgigkPxW+fYSHoNISRAOcTfyO+2jYMa/hCaSiZ39k99bxt4RQCyaL5241JtNUOY fA/A== X-Gm-Message-State: AOJu0YxzNE5RiMF2v30E8cD9vm9CcEYVz50h3X9XHn9yuoXR5fiV1W/F YRcqBHML3j/Fia2ay3G8YVgLbnUDRTdN X-Google-Smtp-Source: AGHT+IFY6uusPq36KufL+4X+7Hc/k0/HksE1P0N2IyD7+YFnHmA6Aj/c8kip3ToyLXVbHX9+OrtD9F9e4WdQ X-Received: from irogers.svl.corp.google.com ([2620:15c:2a3:200:7449:56a1:2b14:305b]) (user=irogers job=sendgmr) by 2002:a05:6902:1603:b0:d7a:bfcf:2d7 with SMTP id bw3-20020a056902160300b00d7abfcf02d7mr100869ybb.6.1696543408563; Thu, 05 Oct 2023 15:03:28 -0700 (PDT) Date: Thu, 5 Oct 2023 15:03:23 -0700 Message-Id: <20231005220324.3635499-1-irogers@google.com> Precedence: bulk X-Mailing-List: bpf@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 X-Mailer: git-send-email 2.42.0.609.gbb76f46606-goog Subject: [PATCH v5 1/2] bpftool: Align output skeleton ELF code From: Ian Rogers To: Quentin Monnet , Alexei Starovoitov , Daniel Borkmann , Andrii Nakryiko , Martin KaFai Lau , Song Liu , Yonghong Song , John Fastabend , KP Singh , Stanislav Fomichev , Hao Luo , Jiri Olsa , bpf@vger.kernel.org, linux-kernel@vger.kernel.org Cc: Ian Rogers , Alan Maguire X-Spam-Status: No, score=-9.6 required=5.0 tests=BAYES_00,DKIMWL_WL_MED, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF, RCVD_IN_DNSWL_BLOCKED,SPF_HELO_NONE,SPF_PASS,USER_IN_DEF_DKIM_WL autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net X-Patchwork-Delegate: bpf@iogearbox.net libbpf accesses the ELF data requiring at least 8 byte alignment, however, the data is generated into a C string that doesn't guarantee alignment. Fix this by assigning to an aligned char array. Use sizeof on the array, less one for the \0 terminator, rather than generating a constant. Fixes: a6cc6b34b93e ("bpftool: Provide a helper method for accessing skeleton's embedded ELF data") Signed-off-by: Ian Rogers Acked-by: Quentin Monnet Reviewed-by: Alan Maguire --- tools/bpf/bpftool/gen.c | 15 +++++++++------ 1 file changed, 9 insertions(+), 6 deletions(-) diff --git a/tools/bpf/bpftool/gen.c b/tools/bpf/bpftool/gen.c index 2883660d6b67..b8ebcee9bc56 100644 --- a/tools/bpf/bpftool/gen.c +++ b/tools/bpf/bpftool/gen.c @@ -1209,7 +1209,7 @@ static int do_skeleton(int argc, char **argv) codegen("\ \n\ \n\ - s->data = (void *)%2$s__elf_bytes(&s->data_sz); \n\ + s->data = (void *)%1$s__elf_bytes(&s->data_sz); \n\ \n\ obj->skeleton = s; \n\ return 0; \n\ @@ -1218,12 +1218,12 @@ static int do_skeleton(int argc, char **argv) return err; \n\ } \n\ \n\ - static inline const void *%2$s__elf_bytes(size_t *sz) \n\ + static inline const void *%1$s__elf_bytes(size_t *sz) \n\ { \n\ - *sz = %1$d; \n\ - return (const void *)\"\\ \n\ - " - , file_sz, obj_name); + static const char data[] __attribute__((__aligned__(8))) = \"\\\n\ + ", + obj_name + ); /* embed contents of BPF object file */ print_hex(obj_data, file_sz); @@ -1231,6 +1231,9 @@ static int do_skeleton(int argc, char **argv) codegen("\ \n\ \"; \n\ + \n\ + *sz = sizeof(data) - 1; \n\ + return (const void *)data; \n\ } \n\ \n\ #ifdef __cplusplus \n\