From patchwork Wed Oct 4 22:23:22 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ian Rogers X-Patchwork-Id: 13409623 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 391E924212 for ; Wed, 4 Oct 2023 22:23:41 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="QYfC+wRu" Received: from mail-yb1-xb4a.google.com (mail-yb1-xb4a.google.com [IPv6:2607:f8b0:4864:20::b4a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id DD75710FB for ; Wed, 4 Oct 2023 15:23:26 -0700 (PDT) Received: by mail-yb1-xb4a.google.com with SMTP id 3f1490d57ef6-d865f1447a2so592381276.2 for ; Wed, 04 Oct 2023 15:23:26 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1696458206; x=1697063006; darn=vger.kernel.org; h=cc:to:from:subject:mime-version:message-id:date:from:to:cc:subject :date:message-id:reply-to; bh=raoMQ3SQ/7ZFelkz0l8EiT5sUCvEdkA2km5MKOLJhzo=; b=QYfC+wRugJ4lQvqgBCiqmcgXHB6ESxeWYPtjzQSoBgY8qUxYUMV3L0OGnyhLxVaOsr cxsqzQ/YEGh7N8UldMs/u2nV20Kr+nvcsiokgQPUdT3xNyLYy+DdZBs6BEiB+Rs7ucLj LMKfYgoIWNgmLYHuIOaEPYtqwtdcjSe9duR2Bu4C2dQz2h3wERt1NbRupbCPadAYuYGB qu/+m9oX+SJRad8fShgk+yHFuVdJvVQssA0AOmvKhDlnn+IAztWjw9gkAA0STxN5cc0N FHOFYKtItacqE/0RgR05bzroVIuuYZzGo3qkRNAJOMC0/HBncopjRm3VtlGu+IPwu2XO /PtA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1696458206; x=1697063006; h=cc:to:from:subject:mime-version:message-id:date:x-gm-message-state :from:to:cc:subject:date:message-id:reply-to; bh=raoMQ3SQ/7ZFelkz0l8EiT5sUCvEdkA2km5MKOLJhzo=; b=l4oZYxsZProrflaLiR9k8qRxQWwa/Q30cdAWI3nNciLJlVV5brHFg0xGIQtD2ljeaV dKkMCznTbxJ0jMk3CfXQSiieE/yMWRD3Qn+QcfCF6J5BJ61NRYrgZAGc8ritvwTI6EYZ cij7P/zmVeHbwl2N0vRYuwhY9xHdLNAU2JOGG8meljrR2y7h7ivLeREKHSlCoCmcjDdN ISM+z1Q8mc+gyOqUQ637r7QNeEvgydA89T9NmWyGlF853lb5u9ithLlzkWoM53ww+gMQ NpOvDw4RbqWojTROc9pzA5UvMdhqEEjnvMyg/VKNTz62aikTgS0KLF/QMfBHKvhYvNYu GxGg== X-Gm-Message-State: AOJu0Yx0V/yqtoRg/j6ZIeY6eOhRF2HsR0Fdov39ZNwndYxSN4pgDaAJ t/bJSrSsdXGTPlPJrfWEdWXt67D8JBqa X-Google-Smtp-Source: AGHT+IHuWIDrX75i83mVKUxiuU6q58yAN8CALuDciPIg46gAx0U1ncoVbvRysJAxkkItHi9M7Z9Ux8p3GNvU X-Received: from irogers.svl.corp.google.com ([2620:15c:2a3:200:f42:a09e:8ee2:1491]) (user=irogers job=sendgmr) by 2002:a25:3442:0:b0:d0e:e780:81b3 with SMTP id b63-20020a253442000000b00d0ee78081b3mr48786yba.2.1696458206114; Wed, 04 Oct 2023 15:23:26 -0700 (PDT) Date: Wed, 4 Oct 2023 15:23:22 -0700 Message-Id: <20231004222323.3503030-1-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 v4 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_NONE, SPF_HELO_NONE,SPF_PASS,USER_IN_DEF_DKIM_WL autolearn=unavailable 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 Reviewed-by: Alan Maguire Acked-by: Quentin Monnet --- 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\