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=-5.3 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE, SPF_PASS,USER_AGENT_SANE_1 autolearn=ham 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 8FE43C47404 for ; Sat, 5 Oct 2019 16:52:20 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 6201022459 for ; Sat, 5 Oct 2019 16:52:20 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="ka9lo2qj" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729561AbfJEQwT (ORCPT ); Sat, 5 Oct 2019 12:52:19 -0400 Received: from mail-ed1-f67.google.com ([209.85.208.67]:39502 "EHLO mail-ed1-f67.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728499AbfJEQwT (ORCPT ); Sat, 5 Oct 2019 12:52:19 -0400 Received: by mail-ed1-f67.google.com with SMTP id a15so8726301edt.6 for ; Sat, 05 Oct 2019 09:52:18 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=date:from:to:cc:subject:message-id:mime-version:content-disposition :user-agent; bh=d9ykpvhm3YkXpauA7Wa3H8Nocq0SnmYsOUAHR5mLQng=; b=ka9lo2qjiZehblCq14J4nvM4wqsN5XFZs/noLiAHrPDqWJiAsf/PzngJKfOYcyKM1P BnSYSFiDKHNZ4TvEm3plCc2VDnGmKcm1KpLXkce7ef3AR9R7Urt4wE5yC1kmI5/bHGyF 2n+a3FIyM0fYGAxeZRXdGJL+5Y8hg9+U6VjjEkswlg1Bhc1lSayJdARQBt/mCbtYI6F4 WBTibtUSl7YZvHM58tsE7jzUGLPIn3DcJHi0iFdRYImmXFhGxdtCTI5R5O77nuenFit9 mCLqoJ6POOhXpuLhKXRimPxJp+OGMWasOtZsBWOgXppS8BX3DtYWjhSRXjWuuFDrc5gx u3tA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:mime-version :content-disposition:user-agent; bh=d9ykpvhm3YkXpauA7Wa3H8Nocq0SnmYsOUAHR5mLQng=; b=SlNXYrZIa8PHmAohV3mAz6IyHSsAamw5V8FGWSfNtNMXsxEp66/Z97FnfKbO0qJ8f3 AcyOFnyUwGPYobUSs0aDga69EZ5jLmEd7z6RxumLjlZAtw2NXB17n7k8J1hFjdBMLWTL CXHTXKdEGehH1Lqx+iBc/6Qj5KnSmbpnNFM4tDKncjDaLZeATyRcm3NItYsWqbRHVof5 7EU5ZfIWsRTukc0YEwgrnTm+Mewh9zesammyz2gbS42afz1iRrZl0u1kLxsIQ5rs/J8r O5X8Lw+I493b1NwWhKkmjqKDKz+dXrHMjB7NK1Ms6oTv3TRsFFkY098BOCGv5xZxagAm EhJg== X-Gm-Message-State: APjAAAUMudURKFOwB4kk2lyhcsLyemnhuIL12ShAs6IuX+hZ5HhQwxeC PbXP0rcxWnpaAQi54zPK0InN52M= X-Google-Smtp-Source: APXvYqyuAWgst+1SPYPfiNiDFN+WjQlj2B21jQQacNuxo9Jhj71WDKl91p6hsTKPMVUIlqMzB7RycA== X-Received: by 2002:a17:906:1f12:: with SMTP id w18mr17156837ejj.224.1570294337577; Sat, 05 Oct 2019 09:52:17 -0700 (PDT) Received: from avx2 ([46.53.253.60]) by smtp.gmail.com with ESMTPSA id o22sm1092576ejr.40.2019.10.05.09.52.16 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Sat, 05 Oct 2019 09:52:17 -0700 (PDT) Date: Sat, 5 Oct 2019 19:52:15 +0300 From: Alexey Dobriyan To: akpm@linux-foundation.org Cc: linux-kernel@vger.kernel.org Subject: [PATCH] elf: extract elf_read() function Message-ID: <20191005165215.GB26927@avx2> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org ELF reads done by the kernel have very complicated error detection code which better live in one place. Signed-off-by: Alexey Dobriyan --- fs/binfmt_elf.c | 49 ++++++++++++++++++++++++------------------------- 1 file changed, 24 insertions(+), 25 deletions(-) --- a/fs/binfmt_elf.c +++ b/fs/binfmt_elf.c @@ -404,6 +404,17 @@ static unsigned long total_mapping_size(const struct elf_phdr *cmds, int nr) ELF_PAGESTART(cmds[first_idx].p_vaddr); } +static int elf_read(struct file *file, void *buf, size_t len, loff_t pos) +{ + ssize_t rv; + + rv = kernel_read(file, buf, len, &pos); + if (unlikely(rv != len)) { + return (rv < 0) ? rv : -EIO; + } + return 0; +} + /** * load_elf_phdrs() - load ELF program headers * @elf_ex: ELF header of the binary whose program headers should be loaded @@ -418,7 +429,6 @@ static struct elf_phdr *load_elf_phdrs(const struct elfhdr *elf_ex, { struct elf_phdr *elf_phdata = NULL; int retval, err = -1; - loff_t pos = elf_ex->e_phoff; unsigned int size; /* @@ -439,9 +449,9 @@ static struct elf_phdr *load_elf_phdrs(const struct elfhdr *elf_ex, goto out; /* Read in the program headers */ - retval = kernel_read(elf_file, elf_phdata, size, &pos); - if (retval != size) { - err = (retval < 0) ? retval : -EIO; + retval = elf_read(elf_file, elf_phdata, size, elf_ex->e_phoff); + if (retval < 0) { + err = retval; goto out; } @@ -720,7 +730,6 @@ static int load_elf_binary(struct linux_binprm *bprm) elf_ppnt = elf_phdata; for (i = 0; i < loc->elf_ex.e_phnum; i++, elf_ppnt++) { char *elf_interpreter; - loff_t pos; if (elf_ppnt->p_type != PT_INTERP) continue; @@ -738,14 +747,10 @@ static int load_elf_binary(struct linux_binprm *bprm) if (!elf_interpreter) goto out_free_ph; - pos = elf_ppnt->p_offset; - retval = kernel_read(bprm->file, elf_interpreter, - elf_ppnt->p_filesz, &pos); - if (retval != elf_ppnt->p_filesz) { - if (retval >= 0) - retval = -EIO; + retval = elf_read(bprm->file, elf_interpreter, elf_ppnt->p_filesz, + elf_ppnt->p_offset); + if (retval < 0) goto out_free_interp; - } /* make sure path is NULL terminated */ retval = -ENOEXEC; if (elf_interpreter[elf_ppnt->p_filesz - 1] != '\0') @@ -764,14 +769,10 @@ static int load_elf_binary(struct linux_binprm *bprm) would_dump(bprm, interpreter); /* Get the exec headers */ - pos = 0; - retval = kernel_read(interpreter, &loc->interp_elf_ex, - sizeof(loc->interp_elf_ex), &pos); - if (retval != sizeof(loc->interp_elf_ex)) { - if (retval >= 0) - retval = -EIO; + retval = elf_read(interpreter, &loc->interp_elf_ex, + sizeof(loc->interp_elf_ex), 0); + if (retval < 0) goto out_free_dentry; - } break; @@ -1181,11 +1182,10 @@ static int load_elf_library(struct file *file) unsigned long elf_bss, bss, len; int retval, error, i, j; struct elfhdr elf_ex; - loff_t pos = 0; error = -ENOEXEC; - retval = kernel_read(file, &elf_ex, sizeof(elf_ex), &pos); - if (retval != sizeof(elf_ex)) + retval = elf_read(file, &elf_ex, sizeof(elf_ex), 0); + if (retval < 0) goto out; if (memcmp(elf_ex.e_ident, ELFMAG, SELFMAG) != 0) @@ -1210,9 +1210,8 @@ static int load_elf_library(struct file *file) eppnt = elf_phdata; error = -ENOEXEC; - pos = elf_ex.e_phoff; - retval = kernel_read(file, eppnt, j, &pos); - if (retval != j) + retval = elf_read(file, eppnt, j, elf_ex.e_phoff); + if (retval < 0) goto out_free_ph; for (j = 0, i = 0; i