From patchwork Tue Apr 16 12:56:41 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: YunQiang Su X-Patchwork-Id: 10902933 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 6E66117E1 for ; Tue, 16 Apr 2019 12:57:03 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 4B1B225E97 for ; Tue, 16 Apr 2019 12:57:03 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 3C3FE287F5; Tue, 16 Apr 2019 12:57:03 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.7 required=2.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,MAILING_LIST_MULTI,RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 8F7FD25E97 for ; Tue, 16 Apr 2019 12:57:02 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727490AbfDPM5B (ORCPT ); Tue, 16 Apr 2019 08:57:01 -0400 Received: from mail-pf1-f193.google.com ([209.85.210.193]:43337 "EHLO mail-pf1-f193.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727228AbfDPM5B (ORCPT ); Tue, 16 Apr 2019 08:57:01 -0400 Received: by mail-pf1-f193.google.com with SMTP id c8so10364738pfd.10 for ; Tue, 16 Apr 2019 05:57:00 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=sender:from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=k7x2sFuioDEqvUFZlpcUlZt4Dq3LaEUtf/EE/DXfhXI=; b=SLcsdEZTZO9Z/BL8/a2ZkqzV31sRH4lhjrC6yI0beZtO8n+H3cGvW+npeq5zY34Yt0 SouOinFid39P7Ka8mABuo378ZmPAf5hIO+nCV0baDpmO1AqxPwQNbCUTeHFF/rqQ1K8Q 9IbS8Uoi1T1cWfRLbvvuUATblMXMxLI/cXm2t8S3gJ3jZ+CEyDUZfhlVTvlj0rP+NuGt kwOsrHJh/wnJZuyl5tieCMd8fQMSfzTxFd/WkZnuYUUP4S8EI4a8b/zWGgFEBXx8HmXJ LS3exlyQYeVxAsgDJPfqUVLuKr6hZOWDofTQyIQxb3UcI4vKRpicAj73EF3aBr0SNPjX /Y1g== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:sender:from:to:cc:subject:date:message-id :mime-version:content-transfer-encoding; bh=k7x2sFuioDEqvUFZlpcUlZt4Dq3LaEUtf/EE/DXfhXI=; b=MUGKkvSsItfD738utMsrMANdOCr4E0yyGrCOwOP5zUTIjAifs/g0BAQwdUhGl/IO1n 0MoqJiH+8gSMszceYgSDtAdbZ4K9Cf55Xl2HE6YbCYbPAfEHuefFembJV+eknGAID2ht ESWrPex78wIDWfq7oTMn1lTysTjI96CWDhtoHxoPwFTN5b+M6DoLFCz+eJHoso73Xg66 +YcMIVPX0FHxHrvSCLEVJZQHFX/7UQuAaJrSwEwbMIpLtPXPlSDlAQ5sGrcrDwXV70sO L/a5Scb6jwwHzi0xCP4NgVmKe3SgtbiBxV965iHgEDMo6oMdqa/7jZng5YeU2ZwA/9/Q 0UNg== X-Gm-Message-State: APjAAAXf/IfAq3FCxhwc/GlJvlE1A2S/+l6yNLHnXT7gIXP/chbUySua yoEVsFDp0V40hSMiJlLD2oB2K4XzDbI= X-Google-Smtp-Source: APXvYqx3EsFbg649ELI/Ts1D5pLwY3X0puOG3t64BH26EoqbDILM22z/bMr1dGGMam+MeaOWGKcTMA== X-Received: by 2002:a63:1203:: with SMTP id h3mr77638649pgl.164.1555419420306; Tue, 16 Apr 2019 05:57:00 -0700 (PDT) Received: from loongson.users.bfsu.cn ([2001:250:218:3698:d4c:a991:7c4e:a8bf]) by smtp.gmail.com with ESMTPSA id f71sm90676390pfc.109.2019.04.16.05.56.58 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Tue, 16 Apr 2019 05:56:59 -0700 (PDT) From: YunQiang Su To: linux-fsdevel@vger.kernel.org Cc: qemu-devel@nongnu.org, pburton@wavecomp.com, YunQiang Su Subject: [PATCH] binfmt_misc: pass info about P flag by AT_FLAGS Date: Tue, 16 Apr 2019 20:56:41 +0800 Message-Id: <20190416125641.3068-1-syq@debian.org> X-Mailer: git-send-email 2.20.1 MIME-Version: 1.0 Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP From: YunQiang Su Currently program invoked by binfmt_misc cannot be aware about whether P flag, aka preserve path is enabled. Some applications like qemu need to know since it has 2 use case: 1. call by hand, like: qemu-mipsel-static test.app OPTION so, qemu have to assume that P option is not enabled. 2. call by binfmt_misc. If qemu cannot know about whether P flag is enabled, distribution's have to set qemu without P flag, and binfmt_misc call qemu like: qemu-mipsel-static /absolute/path/to/test.app OPTION even test.app is not called by absoulute path, like ./relative/path/to/test.app This patch passes this information by the 3rd bits of unused AT_FLAGS. Then, in qemu, we can get this info by: getauxval(AT_FLAGS) & (1<<3) See: https://bugs.launchpad.net/qemu/+bug/1818483 Signed-off-by: YunQiang Su --- fs/binfmt_elf.c | 6 +++++- fs/binfmt_elf_fdpic.c | 9 +++++++-- fs/binfmt_misc.c | 2 ++ include/linux/binfmts.h | 4 ++++ 4 files changed, 18 insertions(+), 3 deletions(-) diff --git a/fs/binfmt_elf.c b/fs/binfmt_elf.c index 09e76b25d833..30688fbad615 100644 --- a/fs/binfmt_elf.c +++ b/fs/binfmt_elf.c @@ -175,6 +175,7 @@ create_elf_tables(struct linux_binprm *bprm, struct elfhdr *exec, unsigned char k_rand_bytes[16]; int items; elf_addr_t *elf_info; + elf_addr_t flags = 0; int ei_index = 0; const struct cred *cred = current_cred(); struct vm_area_struct *vma; @@ -249,7 +250,10 @@ create_elf_tables(struct linux_binprm *bprm, struct elfhdr *exec, NEW_AUX_ENT(AT_PHENT, sizeof(struct elf_phdr)); NEW_AUX_ENT(AT_PHNUM, exec->e_phnum); NEW_AUX_ENT(AT_BASE, interp_load_addr); - NEW_AUX_ENT(AT_FLAGS, 0); + if (bprm->interp_flags & BINPRM_FLAGS_PRESERVE_ARGV0) { + flags |= BINPRM_FLAGS_PRESERVE_ARGV0; + } + NEW_AUX_ENT(AT_FLAGS, flags); NEW_AUX_ENT(AT_ENTRY, exec->e_entry); NEW_AUX_ENT(AT_UID, from_kuid_munged(cred->user_ns, cred->uid)); NEW_AUX_ENT(AT_EUID, from_kuid_munged(cred->user_ns, cred->euid)); diff --git a/fs/binfmt_elf_fdpic.c b/fs/binfmt_elf_fdpic.c index b53bb3729ac1..ba3385be00fb 100644 --- a/fs/binfmt_elf_fdpic.c +++ b/fs/binfmt_elf_fdpic.c @@ -46,7 +46,7 @@ typedef char *elf_caddr_t; -#if 0 +#if 1 #define kdebug(fmt, ...) printk("FDPIC "fmt"\n" ,##__VA_ARGS__ ) #else #define kdebug(fmt, ...) do {} while(0) @@ -511,6 +511,7 @@ static int create_elf_fdpic_tables(struct linux_binprm *bprm, char __user *u_platform, *u_base_platform, *p; int loop; int nr; /* reset for each csp adjustment */ + unsigned long flags = 0; #ifdef CONFIG_MMU /* In some cases (e.g. Hyper-Threading), we want to avoid L1 evictions @@ -651,7 +652,11 @@ static int create_elf_fdpic_tables(struct linux_binprm *bprm, NEW_AUX_ENT(AT_PHENT, sizeof(struct elf_phdr)); NEW_AUX_ENT(AT_PHNUM, exec_params->hdr.e_phnum); NEW_AUX_ENT(AT_BASE, interp_params->elfhdr_addr); - NEW_AUX_ENT(AT_FLAGS, 0); + if (bprm->interp_flags & BINPRM_FLAGS_PRESERVE_ARGV0) { + flags |= BINPRM_FLAGS_PRESERVE_ARGV0; + } + kdebug("AT_FLAGS %ld\n", flags); + NEW_AUX_ENT(AT_FLAGS, flags); NEW_AUX_ENT(AT_ENTRY, exec_params->entry_addr); NEW_AUX_ENT(AT_UID, (elf_addr_t) from_kuid_munged(cred->user_ns, cred->uid)); NEW_AUX_ENT(AT_EUID, (elf_addr_t) from_kuid_munged(cred->user_ns, cred->euid)); diff --git a/fs/binfmt_misc.c b/fs/binfmt_misc.c index aa4a7a23ff99..46c509cd096e 100644 --- a/fs/binfmt_misc.c +++ b/fs/binfmt_misc.c @@ -156,6 +156,8 @@ static int load_misc_binary(struct linux_binprm *bprm) retval = remove_arg_zero(bprm); if (retval) goto ret; + } else { + bprm->interp_flags |= BINPRM_FLAGS_PRESERVE_ARGV0; } if (fmt->flags & MISC_FMT_OPEN_BINARY) { diff --git a/include/linux/binfmts.h b/include/linux/binfmts.h index 688ab0de7810..c082650a0310 100644 --- a/include/linux/binfmts.h +++ b/include/linux/binfmts.h @@ -77,6 +77,10 @@ struct linux_binprm { #define BINPRM_FLAGS_PATH_INACCESSIBLE_BIT 2 #define BINPRM_FLAGS_PATH_INACCESSIBLE (1 << BINPRM_FLAGS_PATH_INACCESSIBLE_BIT) +/* if preserve the argv0 for the interpreter */ +#define BINPRM_FLAGS_PRESERVE_ARGV0_BIT 3 +#define BINPRM_FLAGS_PRESERVE_ARGV0 (1 << BINPRM_FLAGS_PRESERVE_ARGV0_BIT) + /* Function parameter for binfmt->coredump */ struct coredump_params { const kernel_siginfo_t *siginfo;