From patchwork Wed Oct 21 17:37:47 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Richard Henderson X-Patchwork-Id: 1385683 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=nongnu.org (client-ip=209.51.188.17; helo=lists.gnu.org; envelope-from=qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org; receiver=) Authentication-Results: ozlabs.org; dmarc=pass (p=none dis=none) header.from=linaro.org Authentication-Results: ozlabs.org; dkim=pass (2048-bit key; unprotected) header.d=linaro.org header.i=@linaro.org header.a=rsa-sha256 header.s=google header.b=cLidm0Xu; dkim-atps=neutral Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 4CGdQR2QQhz9sSG for ; Thu, 22 Oct 2020 04:53:35 +1100 (AEDT) Received: from localhost ([::1]:42484 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1kVIIn-0004bm-13 for incoming@patchwork.ozlabs.org; Wed, 21 Oct 2020 13:53:33 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:51908) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1kVI3x-0006hC-W2 for qemu-devel@nongnu.org; Wed, 21 Oct 2020 13:38:14 -0400 Received: from mail-pf1-x441.google.com ([2607:f8b0:4864:20::441]:44568) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1kVI3u-0006UY-6c for qemu-devel@nongnu.org; Wed, 21 Oct 2020 13:38:13 -0400 Received: by mail-pf1-x441.google.com with SMTP id f19so1880732pfj.11 for ; Wed, 21 Oct 2020 10:38:08 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=uXEiXCwmZ4IatXzjo8oCm1sQVSclKFFXnkVflorhWjg=; b=cLidm0XuUM7MSAP6Wh9lagSVqpYg6YyccFm218JS/hD14EZYis6gZr3svZWmJGa73s zRzI3nTxuOk5mW47b7AA5A50Pen3l8gTOxYHo2nMzNEJ2wZ44icaoDgey/8fI2yak3tL 2xKaZzfdtgNlTdx32sSyii8MFBGozaDWfvJmPJWOx/ntF6gGXhKhbfz6pfUBofCDrsW5 8lTXsyYoCptmA3dOU3nboqIHctu2ZG/z/bxdNH18RFYpYJ9AS27G5Slh158nX3KwJyuf PJas4AAAR8rYU6kgTgCSFewG2/trEqUyYSV9WmIcYc+MVMa+VHVd1Bi5ePm4OTwo6aKz Jo2Q== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=uXEiXCwmZ4IatXzjo8oCm1sQVSclKFFXnkVflorhWjg=; b=h3X9+u8xUtYYeyjwzO4tKQoZpIGzG1YBpSaS3kHw3CQA9Qzc+s5YKhFls7t0fCMC0d sKk9WqSlUC0yfRpcUo5RC2CCZtKXWH8ZVPkHtNj3r2iXGcqMSYifiZ2vrLtNaUyGMVbL A6vyIScWG20T9F+Ts9McmJhmIG5EVadUui/YNAcLj7uVy8P5l3hNznnUmkY5ncN3tShH 0XTZo6cRfigaSVHgfvZ+ZqOOFloKmwcrN7eFzcc2UB4duGdw3NzTDqYWsdsV3LvyPaVU mUHfMkF5qTf0FmvqxPl+4Zw5InaCUPmIxNbjT85uelYMZtpR30MvGkdNY4QX2IkKaIHQ GeTQ== X-Gm-Message-State: AOAM5328md9jFdPDny+WW0JaLOuqLPmTbD/FvPXTKTzkWu6iXhzy/yoa TEeTtNS6FkUtdx8tP6TEhK3WnXchjY6IiA== X-Google-Smtp-Source: ABdhPJz+wIYocRi8SBDyTYbF5+lWxZAK8g1x/9hBahiJ5k2Qn23OEeECRfU5E6mRC030lFlAaj7+gg== X-Received: by 2002:a62:17c2:0:b029:158:ca2e:3cd7 with SMTP id 185-20020a6217c20000b0290158ca2e3cd7mr4546856pfx.43.1603301886732; Wed, 21 Oct 2020 10:38:06 -0700 (PDT) Received: from localhost.localdomain ([71.212.141.89]) by smtp.gmail.com with ESMTPSA id h5sm2928829pfh.9.2020.10.21.10.38.05 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 21 Oct 2020 10:38:06 -0700 (PDT) From: Richard Henderson To: qemu-devel@nongnu.org Subject: [PATCH v12 10/12] linux-user/elfload: Parse NT_GNU_PROPERTY_TYPE_0 notes Date: Wed, 21 Oct 2020 10:37:47 -0700 Message-Id: <20201021173749.111103-11-richard.henderson@linaro.org> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20201021173749.111103-1-richard.henderson@linaro.org> References: <20201021173749.111103-1-richard.henderson@linaro.org> MIME-Version: 1.0 Received-SPF: pass client-ip=2607:f8b0:4864:20::441; envelope-from=richard.henderson@linaro.org; helo=mail-pf1-x441.google.com X-detected-operating-system: by eggs.gnu.org: No matching host in p0f cache. That's all we know. X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 5.0 requ) BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: peter.maydell@linaro.org Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: "Qemu-devel" This is generic support, with the code disabled for all targets. Signed-off-by: Richard Henderson --- v9: Only map the startup executable with BTI; anything else must be handled by the interpreter. v10: Split out preparatory patches (pmm). v11: Mirror(-ish) the kernel's code structure (pmm). --- linux-user/qemu.h | 4 ++ linux-user/elfload.c | 157 +++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 161 insertions(+) diff --git a/linux-user/qemu.h b/linux-user/qemu.h index 941ca99722..534753ca12 100644 --- a/linux-user/qemu.h +++ b/linux-user/qemu.h @@ -61,6 +61,10 @@ struct image_info { abi_ulong interpreter_loadmap_addr; abi_ulong interpreter_pt_dynamic_addr; struct image_info *other_info; + + /* For target-specific processing of NT_GNU_PROPERTY_TYPE_0. */ + uint32_t note_flags; + #ifdef TARGET_MIPS int fp_abi; int interp_fp_abi; diff --git a/linux-user/elfload.c b/linux-user/elfload.c index 04c04bc260..428dcaa152 100644 --- a/linux-user/elfload.c +++ b/linux-user/elfload.c @@ -1522,6 +1522,15 @@ static void elf_core_copy_regs(target_elf_gregset_t *regs, #include "elf.h" +static bool arch_parse_elf_property(uint32_t pr_type, uint32_t pr_datasz, + const uint32_t *data, + struct image_info *info, + Error **errp) +{ + g_assert_not_reached(); +} +#define ARCH_USE_GNU_PROPERTY 0 + struct exec { unsigned int a_info; /* Use macros N_MAGIC, etc for access */ @@ -2373,6 +2382,150 @@ void probe_guest_base(const char *image_name, abi_ulong guest_loaddr, "@ 0x%" PRIx64 "\n", (uint64_t)guest_base); } +enum { + /* The string "GNU\0" as a magic number. */ + GNU0_MAGIC = const_le32('G' | 'N' << 8 | 'U' << 16), + NOTE_DATA_SZ = 1 * KiB, + NOTE_NAME_SZ = 4, + ELF_GNU_PROPERTY_ALIGN = ELF_CLASS == ELFCLASS32 ? 4 : 8, +}; + +/* + * Process a single gnu_property entry. + * Return false for error. + */ +static bool parse_elf_property(const uint32_t *data, int *off, int datasz, + struct image_info *info, bool have_prev_type, + uint32_t *prev_type, Error **errp) +{ + uint32_t pr_type, pr_datasz, step; + + if (*off > datasz || !QEMU_IS_ALIGNED(*off, ELF_GNU_PROPERTY_ALIGN)) { + goto error_data; + } + datasz -= *off; + data += *off / sizeof(uint32_t); + + if (datasz < 2 * sizeof(uint32_t)) { + goto error_data; + } + pr_type = data[0]; + pr_datasz = data[1]; + data += 2; + datasz -= 2 * sizeof(uint32_t); + step = ROUND_UP(pr_datasz, ELF_GNU_PROPERTY_ALIGN); + if (step > datasz) { + goto error_data; + } + + /* Properties are supposed to be unique and sorted on pr_type. */ + if (have_prev_type && pr_type <= *prev_type) { + if (pr_type == *prev_type) { + error_setg(errp, "Duplicate property in PT_GNU_PROPERTY"); + } else { + error_setg(errp, "Unsorted property in PT_GNU_PROPERTY"); + } + return false; + } + *prev_type = pr_type; + + if (!arch_parse_elf_property(pr_type, pr_datasz, data, info, errp)) { + return false; + } + + *off += 2 * sizeof(uint32_t) + step; + return true; + + error_data: + error_setg(errp, "Ill-formed property in PT_GNU_PROPERTY"); + return false; +} + +/* Process NT_GNU_PROPERTY_TYPE_0. */ +static bool parse_elf_properties(int image_fd, + struct image_info *info, + const struct elf_phdr *phdr, + char bprm_buf[BPRM_BUF_SIZE], + Error **errp) +{ + union { + struct elf_note nhdr; + uint32_t data[NOTE_DATA_SZ / sizeof(uint32_t)]; + } note; + + int n, off, datasz; + bool have_prev_type; + uint32_t prev_type; + + /* Unless the arch requires properties, ignore them. */ + if (!ARCH_USE_GNU_PROPERTY) { + return true; + } + + /* If the properties are crazy large, that's too bad. */ + n = phdr->p_filesz; + if (n > sizeof(note)) { + error_setg(errp, "PT_GNU_PROPERTY too large"); + return false; + } + if (n < sizeof(note.nhdr)) { + error_setg(errp, "PT_GNU_PROPERTY too small"); + return false; + } + + if (phdr->p_offset + n <= BPRM_BUF_SIZE) { + memcpy(¬e, bprm_buf + phdr->p_offset, n); + } else { + ssize_t len = pread(image_fd, ¬e, n, phdr->p_offset); + if (len != n) { + error_setg_errno(errp, errno, "Error reading file header"); + return false; + } + } + + /* + * The contents of a valid PT_GNU_PROPERTY is a sequence + * of uint32_t -- swap them all now. + */ +#ifdef BSWAP_NEEDED + for (int i = 0; i < n / 4; i++) { + bswap32s(note.data + i); + } +#endif + + /* + * Note that nhdr is 3 words, and that the "name" described by namesz + * immediately follows nhdr and is thus at the 4th word. Further, all + * of the inputs to the kernel's round_up are multiples of 4. + */ + if (note.nhdr.n_type != NT_GNU_PROPERTY_TYPE_0 || + note.nhdr.n_namesz != NOTE_NAME_SZ || + note.data[3] != GNU0_MAGIC) { + error_setg(errp, "Invalid note in PT_GNU_PROPERTY"); + return false; + } + off = sizeof(note.nhdr) + NOTE_NAME_SZ; + + datasz = note.nhdr.n_descsz + off; + if (datasz > n) { + error_setg(errp, "Invalid note size in PT_GNU_PROPERTY"); + return false; + } + + have_prev_type = false; + prev_type = 0; + while (1) { + if (off == datasz) { + return true; /* end, exit ok */ + } + if (!parse_elf_property(note.data, &off, datasz, info, + have_prev_type, &prev_type, errp)) { + return false; + } + have_prev_type = true; + } +} + /* Load an ELF image into the address space. IMAGE_NAME is the filename of the image, to use in error messages. @@ -2467,6 +2620,10 @@ static void load_elf_image(const char *image_name, int image_fd, goto exit_errmsg; } *pinterp_name = g_steal_pointer(&interp_name); + } else if (eppnt->p_type == PT_GNU_PROPERTY) { + if (!parse_elf_properties(image_fd, info, eppnt, bprm_buf, &err)) { + goto exit_errmsg; + } } }