From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752364AbcGXPbG (ORCPT ); Sun, 24 Jul 2016 11:31:06 -0400 Received: from alt22.smtp-out.videotron.ca ([70.80.0.73]:34316 "EHLO alt22.smtp-out.videotron.ca" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752145AbcGXPal (ORCPT ); Sun, 24 Jul 2016 11:30:41 -0400 X-Authority-Analysis: v=2.1 cv=QfzGxpvv 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=tBb2bbeoAAAA:8 a=jqeyLuiQrnU0nCDKdPoA:9 a=cvBusfyB2V15izCimMoJ:22 a=Oj-tNtZlA1e06AYgeCfH:22 From: Nicolas Pitre To: Greg Ungerer , linux-fsdevel@vger.kernel.org Cc: Alan Cox , Alexander Viro , David Howells , linux-arm-kernel@lists.infradead.org, linux-m68k@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH v5 12/15] binfmt_flat: allow compressed flat binary format to work on MMU systems Date: Sun, 24 Jul 2016 11:30:26 -0400 Message-Id: <1469374229-21585-13-git-send-email-nicolas.pitre@linaro.org> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1469374229-21585-1-git-send-email-nicolas.pitre@linaro.org> References: <1469374229-21585-1-git-send-email-nicolas.pitre@linaro.org> X-CMAE-Envelope: MS4wfK1bimElig++CI05juLsJ1+mWa+h8041kX+p8/eDyJQOC3yoIxBAP8Dj0lowz0Dohi7XraPgpZG0JP7fV6nIlMX4RJST/RAkCKwNAEoiC7bQxHKlYXDI U7oqlJlNkikShR53xmks6IclUPoQMWFIKkHj2WIgrty34mfHXDuZBzMJYubgXXcWa5MNdNJGBUitrzJDZ1G4hCz5kcMm+y+dQ6tXatZV/dWOcWg1geTKbuu5 bxEOFt85vRH1dNRgXVSros9PT85z6ie04cTv965BAAokt6OsMAh84vhvPeeCNKEzwnADfDAw8EOJpqR5Xyw3fJHU8pkuTeqgj+lmCl0fniEyb5lSpN56v5VS k/F3l1DYtJw+FM28cZSD/PSltE5GHKDHxKZuhMFsjeFNAKa6MTfl4goaCGcH2yK+um8xCN6R4t2tDnFGNJGgAJvmvrh5pbpLpURYfDzgZDCPu/z1osU= Sender: linux-kernel-owner@vger.kernel.org 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 top performance on an MMU system are unlikely to choose this executable format anyway. Signed-off-by: Nicolas Pitre Reviewed-by: Greg Ungerer --- 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 7b999aebad..98cfefadb6 100644 --- a/fs/binfmt_flat.c +++ b/fs/binfmt_flat.c @@ -34,6 +34,7 @@ #include #include #include +#include #include #include @@ -628,6 +629,7 @@ 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 @@ -635,13 +637,51 @@ 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 +#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 /* CONFIG_BINFMT_ZFLAT */ { result = read_code(bprm->file, textpos, 0, text_len); if (!IS_ERR_VALUE(result)) -- 2.7.4