From patchwork Thu Jun 13 07:09:02 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Christoph Hellwig X-Patchwork-Id: 10992849 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 7F27518A6 for ; Thu, 13 Jun 2019 16:37:50 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 6D36823201 for ; Thu, 13 Jun 2019 16:37:50 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 5C2C422B27; Thu, 13 Jun 2019 16:37:50 +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=-5.2 required=2.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,MAILING_LIST_MULTI,RCVD_IN_DNSWL_HI,SUSPICIOUS_RECIPS autolearn=unavailable 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 F06CF2239C for ; Thu, 13 Jun 2019 16:37:49 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731706AbfFMQht (ORCPT ); Thu, 13 Jun 2019 12:37:49 -0400 Received: from bombadil.infradead.org ([198.137.202.133]:41588 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730622AbfFMHKF (ORCPT ); Thu, 13 Jun 2019 03:10:05 -0400 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20170209; h=Content-Transfer-Encoding: MIME-Version:References:In-Reply-To:Message-Id:Date:Subject:Cc:To:From:Sender :Reply-To:Content-Type:Content-ID:Content-Description:Resent-Date:Resent-From :Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Id:List-Help: List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=3rmB9mZtF5v1vdin9NeTCejCyapH4H0eIkkGVnBNw6E=; b=cirzpiK4G5e+jr8gW5t+hWpapy iAxTWKRolwqWwcJpN8nTm+SVI94jhE4/O3lF4D3M7CtoCgFJPq48GmcM17OopXqktTzAyQwSME9sI w1SU4LIjwOku5tA+SCxb73hPZTvipgnbEuOumSNUjZBruFQneSGMXoTZdnyhHgIO7wNL3SA1HsJSh xIgK8GmmRHkKUBT+UI6kxmM55LELuEZDNBbVVPJhK5E6quXnPypS/QEwrLWmaGCxgVrtnCCpR/L6u 9Q2tMOqVdAMmDEaeq5xXtBTOvVVAXdWn3IIfxAF2HzG4whA8F3djTxqWQ14HHSB/4ZHZv9dbsWFjS rJHmdR/Q==; Received: from mpp-cp1-natpool-1-013.ethz.ch ([82.130.71.13] helo=localhost) by bombadil.infradead.org with esmtpsa (Exim 4.92 #3 (Red Hat Linux)) id 1hbJry-0004XS-49; Thu, 13 Jun 2019 07:09:58 +0000 From: Christoph Hellwig To: Greg Ungerer Cc: Michal Simek , linux-arm-kernel@lists.infradead.org, linux-c6x-dev@linux-c6x.org, uclinux-h8-devel@lists.sourceforge.jp, linux-m68k@lists.linux-m68k.org, linux-riscv@lists.infradead.org, linux-sh@vger.kernel.org, linux-xtensa@linux-xtensa.org, linux-kernel@vger.kernel.org Subject: [PATCH 16/17] binfmt_flat: don't offset the data start Date: Thu, 13 Jun 2019 09:09:02 +0200 Message-Id: <20190613070903.17214-17-hch@lst.de> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190613070903.17214-1-hch@lst.de> References: <20190613070903.17214-1-hch@lst.de> MIME-Version: 1.0 X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org. See http://www.infradead.org/rpr.html Sender: linux-sh-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-sh@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Ever since the initial commit of the binfmt_flat shared library support back in the bitkeeper days we've offset the actual in-memory .data start by one field per possible shared library, or 1 in case shared library support isn't enabled. I can't find anything in the loader that actually makes use of it, nor was it present before shared library support it. Signed-off-by: Christoph Hellwig --- fs/binfmt_flat.c | 20 ++++++++------------ 1 file changed, 8 insertions(+), 12 deletions(-) diff --git a/fs/binfmt_flat.c b/fs/binfmt_flat.c index ccd9843e979e..80d902fb46e3 100644 --- a/fs/binfmt_flat.c +++ b/fs/binfmt_flat.c @@ -573,7 +573,7 @@ static int load_flat_file(struct linux_binprm *bprm, goto err; } - len = data_len + extra + MAX_SHARED_LIBS * sizeof(unsigned long); + len = data_len + extra; len = PAGE_ALIGN(len); realdatastart = vm_mmap(NULL, 0, len, PROT_READ|PROT_WRITE|PROT_EXEC, MAP_PRIVATE, 0); @@ -587,9 +587,7 @@ static int load_flat_file(struct linux_binprm *bprm, vm_munmap(textpos, text_len); goto err; } - datapos = ALIGN(realdatastart + - MAX_SHARED_LIBS * sizeof(unsigned long), - FLAT_DATA_ALIGN); + datapos = ALIGN(realdatastart, FLAT_DATA_ALIGN); pr_debug("Allocated data+bss+stack (%u bytes): %lx\n", data_len + bss_len + stack_len, datapos); @@ -619,7 +617,7 @@ static int load_flat_file(struct linux_binprm *bprm, memp_size = len; } else { - len = text_len + data_len + extra + MAX_SHARED_LIBS * sizeof(u32); + len = text_len + data_len + extra; len = PAGE_ALIGN(len); textpos = vm_mmap(NULL, 0, len, PROT_READ | PROT_EXEC | PROT_WRITE, MAP_PRIVATE, 0); @@ -634,9 +632,7 @@ static int load_flat_file(struct linux_binprm *bprm, } realdatastart = textpos + ntohl(hdr->data_start); - datapos = ALIGN(realdatastart + - MAX_SHARED_LIBS * sizeof(u32), - FLAT_DATA_ALIGN); + datapos = ALIGN(realdatastart, FLAT_DATA_ALIGN); reloc = (__be32 __user *) (datapos + (ntohl(hdr->reloc_start) - text_len)); @@ -653,8 +649,9 @@ static int load_flat_file(struct linux_binprm *bprm, (text_len + full_data - sizeof(struct flat_hdr)), 0); - memmove((void *) datapos, (void *) realdatastart, - full_data); + if (datapos != realdatastart) + memmove((void *)datapos, (void *)realdatastart, + full_data); #else /* * This is used on MMU systems mainly for testing. @@ -710,8 +707,7 @@ static int load_flat_file(struct linux_binprm *bprm, if (IS_ERR_VALUE(result)) { ret = result; pr_err("Unable to read code+data+bss, errno %d\n", ret); - vm_munmap(textpos, text_len + data_len + extra + - MAX_SHARED_LIBS * sizeof(u32)); + vm_munmap(textpos, text_len + data_len + extra); goto err; } }