From nobody Wed Dec 17 08:00:51 2025 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 59608E776CE for ; Mon, 2 Oct 2023 22:32:29 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235647AbjJBWca (ORCPT ); Mon, 2 Oct 2023 18:32:30 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:45664 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229768AbjJBWc2 (ORCPT ); Mon, 2 Oct 2023 18:32:28 -0400 Received: from mail-yw1-x114a.google.com (mail-yw1-x114a.google.com [IPv6:2607:f8b0:4864:20::114a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D7FE79D for ; Mon, 2 Oct 2023 15:32:25 -0700 (PDT) Received: by mail-yw1-x114a.google.com with SMTP id 00721157ae682-59b5a586da6so1834817b3.1 for ; Mon, 02 Oct 2023 15:32:25 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1696285945; x=1696890745; darn=vger.kernel.org; h=cc:to:from:subject:mime-version:message-id:date:from:to:cc:subject :date:message-id:reply-to; bh=kSFAh0qqGx45G6TQa/MZdM1IdFSztj1awjWbA+mcycU=; b=DxTvXFlnBlAEnK/Z/LDEasydqWeFp+BhkZSX1w3U/+eDhazMQfmeswKD3BdvlVraOn cTVbL4SHp5AOOa0dJqktCXfyWyfioimKkY/MAdiT3aF4A6cuqRjZq8mfW0TyfVdz+bAt IKvlW98J3gUn9EB5fPTWhk0GdC0rUcqK5QI/rrGgw7DgFWGKIJ3b9X6xKkuv6A9BlrsH kyEypAK0DNk+MltSxAJQKP3lgCvIvgAA50cJi+pAlVDpu+FDvTz6ZbfHbkqn3GYAf/ng ZrAjKdd8+0RsfW5mCkCYHk93OkdeloZ6ZOPRNY2M2zrUq+jdo70qm6UgMKIS/o80PYQP oyCA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1696285945; x=1696890745; h=cc:to:from:subject:mime-version:message-id:date:x-gm-message-state :from:to:cc:subject:date:message-id:reply-to; bh=kSFAh0qqGx45G6TQa/MZdM1IdFSztj1awjWbA+mcycU=; b=Vhl6WlaMnHPJ15BJxT2cwBKX8DmRLixtEwYWyVm0xNJMePcFJU3x8tw7WIwQXMUgUg KgWgjgerlQ3yWAEFlFLcaiNnT7lbvvj6gmY5tyS0+zo9u6VBiLuqB4+caWpuLmh+NRPu SdULC7mEjDBzHI4QiG4HvsKFkwdxAvWYjLo9bce9KQzQAvKVJMkbQgcD0y6qebdvzGzW TH/mmvTOkH0tOE2DTrkSmed85sVofmGic9WhVt8ahYeDcs5C1nX7kIyKfPABaTsMyp7w IouCBxuFy2Y8ax2wCZ1SDiRAkj8oM3sORSQkoP98sGOK8pZOkcRTEtAuv4kaJE4S9IQ/ weBQ== X-Gm-Message-State: AOJu0YykDGeXvQBXurPZVZR/McpRxpBqgt3YFnZNcpnShXyvLHdE/HGQ Aq8vpcNgKwgPrwxhHxgFdXLXta6WUpuy X-Google-Smtp-Source: AGHT+IGeGI7meiKgN62+V+QzM1QfTNOH6LmefzUD57qfCucPSiPf185y4PcRsqMKPnnkUk8hSDt7462RNtWP X-Received: from irogers.svl.corp.google.com ([2620:15c:2a3:200:a907:e439:3a86:b259]) (user=irogers job=sendgmr) by 2002:a05:690c:4607:b0:595:7304:68e5 with SMTP id gw7-20020a05690c460700b00595730468e5mr19825ywb.0.1696285945027; Mon, 02 Oct 2023 15:32:25 -0700 (PDT) Date: Mon, 2 Oct 2023 15:32:19 -0700 Message-Id: <20231002223219.2966816-1-irogers@google.com> Mime-Version: 1.0 X-Mailer: git-send-email 2.42.0.582.g8ccd20d70d-goog Subject: [PATCH v1] 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 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" 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. Signed-off-by: Ian Rogers 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 =3D (void *)%2$s__elf_bytes(&s->data_sz); \n\ + s->data =3D (void *)%1$s__elf_bytes(&s->data_sz); \n\ \n\ obj->skeleton =3D 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 =3D %1$d; \n\ - return (const void *)\"\\ \n\ - " - , file_sz, obj_name); + static const char data[] __attribute__((__aligned__(8))) =3D \"\\\n\ + ", + obj_name + ); =20 /* 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 =3D sizeof(data) - 1; \n\ + return (const void *)data; \n\ } \n\ \n\ #ifdef __cplusplus \n\ --=20 2.42.0.582.g8ccd20d70d-goog