From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: 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 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> In-Reply-To: <1468812716-30537-1-git-send-email-nicolas.pitre@linaro.org> References: <1468812716-30537-1-git-send-email-nicolas.pitre@linaro.org> Sender: linux-fsdevel-owner@vger.kernel.org List-ID: 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)) -- 2.7.4