From patchwork Tue Jul 12 21:27:42 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Nicolas Pitre X-Patchwork-Id: 71890 Delivered-To: patch@linaro.org Received: by 10.140.29.52 with SMTP id a49csp685091qga; Tue, 12 Jul 2016 14:45:45 -0700 (PDT) X-Received: by 10.66.51.137 with SMTP id k9mr7683787pao.49.1468359933796; Tue, 12 Jul 2016 14:45:33 -0700 (PDT) Return-Path: Received: from vger.kernel.org (vger.kernel.org. [209.132.180.67]) by mx.google.com with ESMTP id hb9si3239207pac.193.2016.07.12.14.45.33; Tue, 12 Jul 2016 14:45:33 -0700 (PDT) Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; Authentication-Results: mx.google.com; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=fail (p=NONE dis=NONE) header.from=linaro.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752242AbcGLVow (ORCPT + 30 others); Tue, 12 Jul 2016 17:44:52 -0400 Received: from alt42.smtp-out.videotron.ca ([23.233.128.29]:31532 "EHLO alt42.smtp-out.videotron.ca" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751921AbcGLVnc (ORCPT ); Tue, 12 Jul 2016 17:43:32 -0400 Received: from yoda.home ([96.23.157.65]) by Videotron with SMTP id N5Dlb85g76cTKN5DmbUNpI; Tue, 12 Jul 2016 17:28:02 -0400 X-Authority-Analysis: v=2.1 cv=TfA2zUkh 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 A5AF32DA0696; Tue, 12 Jul 2016 17:28:00 -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 10/10] binfmt_flat: allow compressed flat binary format to work on MMU systems Date: Tue, 12 Jul 2016 17:27:42 -0400 Message-Id: <1468358862-11799-11-git-send-email-nicolas.pitre@linaro.org> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1468358862-11799-1-git-send-email-nicolas.pitre@linaro.org> References: <1468358862-11799-1-git-send-email-nicolas.pitre@linaro.org> X-CMAE-Envelope: MS4wfJJglJE/LmlAnj7SUMl9xmuEsrlB8Uro7pFsskuafY6QTCIsTPfpoUVMrubf1B1iCHFG7eIcmVg6LKUrxki8uwfnMHzpqQka3EeTiqdQwc1QdPmGkudH 3aBKwl/z+SimbcBWEnt0ZZ7naGsA1e9LQVjmSCdi6tGaebNCebRucC6ZGiBWr85FWXKmFrgv7a+NQ4T3Iwo8cAPY0dq/YgXQo2Va+zHqNNJYkVM6HfSDkg+T A1W7apSV+Ehv+JTFOO1apHqlwFd5oWKxiDYzp6850vBqcYBLb7fDchBwuENexrAk3Rfqjd+TkgGlVnvsX6dssg== Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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(-) -- 2.7.4 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))