From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-20.6 required=3.0 tests=BAYES_00,DKIMWL_WL_MED, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, USER_AGENT_GIT,USER_IN_DEF_DKIM_WL autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id DEC77C433E0 for ; Fri, 31 Jul 2020 18:37:55 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id BEAAA208E4 for ; Fri, 31 Jul 2020 18:37:55 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="kSNBHuhv" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2387834AbgGaShy (ORCPT ); Fri, 31 Jul 2020 14:37:54 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60648 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730040AbgGaShv (ORCPT ); Fri, 31 Jul 2020 14:37:51 -0400 Received: from mail-qk1-x74a.google.com (mail-qk1-x74a.google.com [IPv6:2607:f8b0:4864:20::74a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B9881C061574 for ; Fri, 31 Jul 2020 11:37:50 -0700 (PDT) Received: by mail-qk1-x74a.google.com with SMTP id k142so21390367qke.7 for ; Fri, 31 Jul 2020 11:37:50 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=date:in-reply-to:message-id:mime-version:references:subject:from:to :cc; bh=5v86mhTzM4SZYwpUDzMMNrk+SN/FmVXE8SoMYa53F6Y=; b=kSNBHuhvWiu3Edhc80EshTZNiBJwW7/jgs6V28cgkNyxmuvHy7vqFAFbcpT5BtWxoh gZ0IV7fMZlyWMviQSeHw/mWYkqtXLjPVr1Umbt5L3Mk+43Msb33WT/fLBgwpDyV4ZX2w rInWxFkHHL9er683V4RC0fWxdftbZ4D5mGsLGvW0aYLQ5TOBI9MvQym9To7xht1lLt6F 4839tMbjgQBpMh5PHT/P/cnss4XwATs5lqiRn+TyG219C6xvydjpIVAllNALhq+uolGP 8WAM3y3vsmxQKxw0gUpzOrYB497D+jxud8jvp1LlhWLmTXfbnlkWn/B+iju5MmT5p3su d/3A== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:in-reply-to:message-id:mime-version :references:subject:from:to:cc; bh=5v86mhTzM4SZYwpUDzMMNrk+SN/FmVXE8SoMYa53F6Y=; b=Qw5Hp5bpxtrFIH0dldB8hoVFs5Yan7oRy0l1/SlBkEhFsAsmcdTp07V5DbB0BcYxMC uxvZIGawhcqzDiXss+2twWYaPWNb/3py85ceiGSfDBA6m/vVwt+jHiICZHPVJzNriW5/ pNwlGsicgRTa479ajCJDhQF+nic2aMmmooXXkWy2oeFFeXOd4r6sfxhED4sWQcNIbEVs iRjIq3jBqF+0cewp6NS4nLc/DPuU/P/nLj/nPkiT5fnlRt3nMd8F1m0VJmXccJkD+pnR 0qwiKqK5uI2DFsiUwhX5Xjk2t9Xl/549oX9/J1hCBmztX53rK2bURQ+akN3SKDpSYdyy xm+g== X-Gm-Message-State: AOAM532QeAbUHbLiw+JEX9yZFzCEAD9iU3e5IDtEK5YCaPZs5jHncSBr 2DA1DlU5SXYaG+x0KINw+e67PO4PmP27d1s= X-Google-Smtp-Source: ABdhPJwjzJJL2kQeuj1qJzZxqRaRImKtWaLo5X70m4f+HV9AozHw6bI9+HYOgUTiJdz2IxZ3sUVEDtCfABQ2Xls= X-Received: by 2002:a0c:ec86:: with SMTP id u6mr5351729qvo.58.1596220669859; Fri, 31 Jul 2020 11:37:49 -0700 (PDT) Date: Fri, 31 Jul 2020 14:37:44 -0400 In-Reply-To: <20200731183745.1669355-1-ckennelly@google.com> Message-Id: <20200731183745.1669355-3-ckennelly@google.com> Mime-Version: 1.0 References: <20200731183745.1669355-1-ckennelly@google.com> X-Mailer: git-send-email 2.28.0.163.g6104cc2f0b6-goog Subject: [PATCH 2/2 v2] Add self-test for verifying load alignment. From: Chris Kennelly To: Alexander Viro , Alexey Dobriyan , Song Liu Cc: David Rientjes , Ian Rogers , Hugh Dickens , Andrew Morton , Suren Baghdasaryan , Sandeep Patil , Fangrui Song , Nick Desaulniers , clang-built-linux@googlegroups.com, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, Chris Kennelly Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org This produces a PIE binary with a variety of p_align requirements, suitable for verifying that the load address meets that alignment requirement. Signed-off-by: Chris Kennelly --- tools/testing/selftests/exec/.gitignore | 1 + tools/testing/selftests/exec/Makefile | 9 ++- tools/testing/selftests/exec/load_address.c | 68 +++++++++++++++++++++ 3 files changed, 76 insertions(+), 2 deletions(-) create mode 100644 tools/testing/selftests/exec/load_address.c diff --git a/tools/testing/selftests/exec/.gitignore b/tools/testing/selftests/exec/.gitignore index 94b02a18f230b..80f57881e9146 100644 --- a/tools/testing/selftests/exec/.gitignore +++ b/tools/testing/selftests/exec/.gitignore @@ -7,6 +7,7 @@ execveat.moved execveat.path.ephemeral execveat.ephemeral execveat.denatured +/load_address_* /recursion-depth xxxxxxxx* pipe diff --git a/tools/testing/selftests/exec/Makefile b/tools/testing/selftests/exec/Makefile index 4453b8f8def37..81cd5d9860629 100644 --- a/tools/testing/selftests/exec/Makefile +++ b/tools/testing/selftests/exec/Makefile @@ -4,7 +4,7 @@ CFLAGS += -Wno-nonnull CFLAGS += -D_GNU_SOURCE TEST_PROGS := binfmt_script -TEST_GEN_PROGS := execveat +TEST_GEN_PROGS := execveat load_address_4096 load_address_2097152 load_address_16777216 TEST_GEN_FILES := execveat.symlink execveat.denatured script subdir pipe # Makefile is a run-time dependency, since it's accessed by the execveat test TEST_FILES := Makefile @@ -26,4 +26,9 @@ $(OUTPUT)/execveat.symlink: $(OUTPUT)/execveat $(OUTPUT)/execveat.denatured: $(OUTPUT)/execveat cp $< $@ chmod -x $@ - +$(OUTPUT)/load_address_4096: load_address.c + $(CC) $(CFLAGS) $(LDFLAGS) -Wl,-z,max-page-size=0x1000 -pie $< -o $@ +$(OUTPUT)/load_address_2097152: load_address.c + $(CC) $(CFLAGS) $(LDFLAGS) -Wl,-z,max-page-size=0x200000 -pie $< -o $@ +$(OUTPUT)/load_address_16777216: load_address.c + $(CC) $(CFLAGS) $(LDFLAGS) -Wl,-z,max-page-size=0x1000000 -pie $< -o $@ diff --git a/tools/testing/selftests/exec/load_address.c b/tools/testing/selftests/exec/load_address.c new file mode 100644 index 0000000000000..d487c2f6a6150 --- /dev/null +++ b/tools/testing/selftests/exec/load_address.c @@ -0,0 +1,68 @@ +// SPDX-License-Identifier: GPL-2.0-only +#ifndef _GNU_SOURCE +#define _GNU_SOURCE +#endif +#include +#include +#include + +struct Statistics { + unsigned long long load_address; + unsigned long long alignment; +}; + +int ExtractStatistics(struct dl_phdr_info *info, size_t size, void *data) +{ + struct Statistics *stats = (struct Statistics *) data; + int i; + + if (info->dlpi_name != NULL && info->dlpi_name[0] != '\0') { + // Ignore headers from other than the executable. + return 2; + } + + stats->load_address = (unsigned long long) info->dlpi_addr; + stats->alignment = 0; + + for (i = 0; i < info->dlpi_phnum; i++) { + if (info->dlpi_phdr[i].p_type != PT_LOAD) + continue; + + if (info->dlpi_phdr[i].p_align > stats->alignment) + stats->alignment = info->dlpi_phdr[i].p_align; + } + + return 1; // Terminate dl_iterate_phdr. +} + +int main(int argc, char **argv) +{ + struct Statistics extracted; + unsigned long long misalign; + int ret; + + ret = dl_iterate_phdr(ExtractStatistics, &extracted); + if (ret != 1) { + fprintf(stderr, "FAILED\n"); + return 1; + } + + if (extracted.alignment == 0) { + fprintf(stderr, "No alignment found\n"); + return 1; + } else if (extracted.alignment & (extracted.alignment - 1)) { + fprintf(stderr, "Alignment is not a power of 2\n"); + return 1; + } + + misalign = extracted.load_address & (extracted.alignment - 1); + if (misalign) { + printf("alignment = %llu, load_address = %llu\n", + extracted.alignment, extracted.load_address); + fprintf(stderr, "FAILED\n"); + return 1; + } + + fprintf(stderr, "PASS\n"); + return 0; +} -- 2.28.0.163.g6104cc2f0b6-goog