From patchwork Mon Jul 18 03:31:56 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Nicolas Pitre X-Patchwork-Id: 9233987 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id A615860756 for ; Mon, 18 Jul 2016 03:32:49 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 99B4E26B41 for ; Mon, 18 Jul 2016 03:32:49 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 8D9BC26C2F; Mon, 18 Jul 2016 03:32:49 +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=-6.9 required=2.0 tests=BAYES_00,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 E75CD212F2 for ; Mon, 18 Jul 2016 03:32:48 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751761AbcGRDcc (ORCPT ); Sun, 17 Jul 2016 23:32:32 -0400 Received: from alt22.smtp-out.videotron.ca ([70.80.0.73]:54117 "EHLO alt22.smtp-out.videotron.ca" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751452AbcGRDcM (ORCPT ); Sun, 17 Jul 2016 23:32:12 -0400 Received: from yoda.home ([96.23.157.65]) by Videotron with SMTP id OzHubax3TPTiyOzHvb7nSk; Sun, 17 Jul 2016 23:32:11 -0400 X-Authority-Analysis: v=2.1 cv=L469O7n8 c=1 sm=1 tr=0 a=keA3yYpnlypCNW5BNWqu+w==:117 a=keA3yYpnlypCNW5BNWqu+w==:17 a=L9H7d07YOLsA:10 a=9cW_t1CCXrUA:10 a=s5jvgZ67dGcA:10 a=cAmyUtKerLwA:10 a=KKAkSRfTAAAA:8 a=jqeyLuiQrnU0nCDKdPoA:9 a=cvBusfyB2V15izCimMoJ:22 Received: from xanadu.home (xanadu.home [192.168.2.2]) by yoda.home (Postfix) with ESMTP id EA2802DA0696; Sun, 17 Jul 2016 23:32:08 -0400 (EDT) From: Nicolas Pitre To: linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org Cc: Alexander Viro , David Howells , Greg Ungerer Subject: [PATCH v2 10/10] binfmt_flat: allow compressed flat binary format to work on MMU systems Date: Sun, 17 Jul 2016 23:31:56 -0400 Message-Id: <1468812716-30537-11-git-send-email-nicolas.pitre@linaro.org> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1468812716-30537-1-git-send-email-nicolas.pitre@linaro.org> References: <1468812716-30537-1-git-send-email-nicolas.pitre@linaro.org> X-CMAE-Envelope: MS4wfMs/z9Z+RXTMbeRLLeXbYXq5FwC95VrR/L2SKYtD5Z1apygV/nXt7FbE7WiQlmkR7oQHwlQA3Re6u5AMEWQSGE2XeEO6McnBQqYhvdC61YTc25LHM3mu WPeSCnFsFTnFNO7PWhdxcqauP5efooPVHPQlmulzf4dmZJefNoReZnQuLed/gISULps4tlof9t7MCszaVmW4H1I5IczZa8cq2mJplh9/Z60s1Dnm4pOP0UMq /+njCvLhfYnyp4VT3Y5eHbxiGJVZvrmRZCYdRGtqNCtLeJ7gUqfa9a/YASKiS8zAaxD2lhsgOcMX7xtIyvKg9A== 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 Let's take the simple and obvious approach by decompressing the binary into a kernel buffer and then copying it to user space. Those who are looking for more performance on a MMU system are unlikely to choose this executable format anyway. Signed-off-by: Nicolas Pitre --- fs/binfmt_flat.c | 44 ++++++++++++++++++++++++++++++++++++++++++-- 1 file changed, 42 insertions(+), 2 deletions(-) diff --git a/fs/binfmt_flat.c b/fs/binfmt_flat.c index 4cb0c4b6ae..24deae4dcb 100644 --- a/fs/binfmt_flat.c +++ b/fs/binfmt_flat.c @@ -35,6 +35,7 @@ #include #include #include +#include #include #include @@ -637,6 +638,7 @@ static int load_flat_file(struct linux_binprm * bprm, * load it all in and treat it like a RAM load from now on */ if (flags & FLAT_FLAG_GZIP) { +#ifndef CONFIG_MMU result = decompress_exec(bprm, sizeof (struct flat_hdr), (((char *) textpos) + sizeof (struct flat_hdr)), (text_len + full_data @@ -644,14 +646,52 @@ static int load_flat_file(struct linux_binprm * bprm, 0); memmove((void *) datapos, (void *) realdatastart, full_data); +#else + /* + * This is used on MMU systems mainly for testing. + * Let's use a kernel buffer to simplify things. + */ + long unz_text_len = text_len - sizeof(struct flat_hdr); + long unz_len = unz_text_len + full_data; + char *unz_data = vmalloc(unz_len); + if (!unz_data) { + result = -ENOMEM; + } else { + result = decompress_exec(bprm, sizeof(struct flat_hdr), + unz_data, unz_len, 0); + if (result == 0 && + (copy_to_user((void __user *)textpos + sizeof(struct flat_hdr), + unz_data, unz_text_len) || + copy_to_user((void __user *)datapos, + unz_data + unz_text_len, full_data))) + result = -EFAULT; + vfree(unz_data); + } +#endif } else if (flags & FLAT_FLAG_GZDATA) { result = read_code(bprm->file, textpos, 0, text_len); - if (!IS_ERR_VALUE(result)) + if (!IS_ERR_VALUE(result)) { +#ifndef CONFIG_MMU result = decompress_exec(bprm, text_len, (char *) datapos, full_data, 0); +#else + char *unz_data = vmalloc(full_data); + if (!unz_data) { + result = -ENOMEM; + } else { + result = decompress_exec(bprm, text_len, + unz_data, full_data, 0); + if (result == 0 && + copy_to_user((void __user *)datapos, + unz_data, full_data)) + result = -EFAULT; + vfree(unz_data); + } +#endif + } } else -#endif +#endif /* CONFIG_BINFMT_ZFLAT */ { result = read_code(bprm->file, textpos, 0, text_len); if (!IS_ERR_VALUE(result))