From patchwork Mon Mar 6 21:55:26 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kees Cook X-Patchwork-Id: 9608433 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 9EBD0604DC for ; Tue, 7 Mar 2017 09:41:32 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 8B8CA2849F for ; Tue, 7 Mar 2017 09:41:32 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 7CCE2284D8; Tue, 7 Mar 2017 09:41:32 +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=-6.3 required=2.0 tests=BAYES_00,DKIM_SIGNED, RCVD_IN_DNSWL_HI, RCVD_IN_SORBS_SPAM, T_DKIM_INVALID 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 DBE3F2849F for ; Tue, 7 Mar 2017 09:41:31 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753504AbdCGJla (ORCPT ); Tue, 7 Mar 2017 04:41:30 -0500 Received: from mail-pf0-f169.google.com ([209.85.192.169]:33969 "EHLO mail-pf0-f169.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752039AbdCGJl2 (ORCPT ); Tue, 7 Mar 2017 04:41:28 -0500 Received: by mail-pf0-f169.google.com with SMTP id v190so35960213pfb.1 for ; Tue, 07 Mar 2017 01:41:27 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; h=from:to:cc:subject:date:message-id:in-reply-to:references; bh=eTNQ9hJV7HR/B5eT6f489Ldq7/nFVTcE2pBGIivXIM0=; b=mKY3IcM0OK1w+xJhan2AOrC1DJdcrRsQeNyCdhGWvp1th88M7P54U2b6M28u2W4iHC uLrN8+YP6Cfwbfi6poJj5b7Gy+8ipM9Gy8mkMjnBVsz5HSZJtbgKiLEJ2JxmKnhlAYcK voDrP+/j7punERMPZWYjix8q485dJquM/E7kg= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references; bh=eTNQ9hJV7HR/B5eT6f489Ldq7/nFVTcE2pBGIivXIM0=; b=DmJFnRM8xbfat2/NxhlKss0n/mLetTox2ZAVjVSO1cRcTZ/YSgEGux33peayeM8Y7X UEYSYWtlHynK1kpMOShso9eJn98TNyzpba+Ul/Qfp0W6qDNIU2FPgloNjv5M2XNZTJiO Xomc3Xagcv/HlnGTyHtSlD6V+dsyK8EjbkD0c/kQcSmm3nn7EsVg+qDXShr3Rvaa0iFK E1JwpRPr1SU065brmrgLoREOIMqLAOAP9qKdai0WuOY/9Xq8eKygpT9Ax4SdvPRauu1R O9JC7YddatkwMp8AqBPatK6/cUSt8k0ewt3AKMjI4f/k32gChghQR3rlLoglRdhFOSlp IYFQ== X-Gm-Message-State: AMke39lihZ6KNKgJ8DmkObpVpKrupA16svvTdSYk/ONsQYoURXjtACCPMc34Rsbr+uF9JVqh X-Received: by 10.84.194.129 with SMTP id h1mr29796871pld.56.1488837341546; Mon, 06 Mar 2017 13:55:41 -0800 (PST) Received: from www.outflux.net ([2002:ada4:7085:0:205a:2b55:4e6d:7d63]) by smtp.gmail.com with ESMTPSA id h9sm41362045pfd.103.2017.03.06.13.55.38 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Mon, 06 Mar 2017 13:55:38 -0800 (PST) From: Kees Cook To: linux-kernel@vger.kernel.org Cc: Kees Cook , Nobuhiro Iwamatsu , Qiuxu Zhuo , Ard Biesheuvel , Anton Vorontsov , Colin Cross , Tony Luck , Benjamin Herrenschmidt , Paul Mackerras , Michael Ellerman , "Rafael J. Wysocki" , Len Brown , Matt Fleming , Nathan Fontenot , Pan Xinhui , Daniel Axtens , Paul Gortmaker , Geliang Tang , linuxppc-dev@lists.ozlabs.org, linux-acpi@vger.kernel.org, linux-efi@vger.kernel.org, linux-doc@vger.kernel.org Subject: [PATCH 12/18] pstore: Pass record contents instead of copying Date: Mon, 6 Mar 2017 13:55:26 -0800 Message-Id: <1488837332-71582-13-git-send-email-keescook@chromium.org> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1488837332-71582-1-git-send-email-keescook@chromium.org> References: <1488837332-71582-1-git-send-email-keescook@chromium.org> Sender: linux-acpi-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-acpi@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP pstore_mkfile() shouldn't have to memcpy the record contents. It can use the existing copy instead. This adjusts the allocation lifetime management and renames the contents variable from "data" to "buf" to assist moving to struct pstore_record in the future. Signed-off-by: Kees Cook --- fs/pstore/inode.c | 22 +++++++++++++++------- fs/pstore/platform.c | 16 ++++++++++++---- 2 files changed, 27 insertions(+), 11 deletions(-) diff --git a/fs/pstore/inode.c b/fs/pstore/inode.c index a98787bab3e6..3d1f047e4f41 100644 --- a/fs/pstore/inode.c +++ b/fs/pstore/inode.c @@ -52,7 +52,7 @@ struct pstore_private { u64 id; int count; ssize_t size; - char data[]; + char *buf; }; struct pstore_ftrace_seq_data { @@ -63,6 +63,14 @@ struct pstore_ftrace_seq_data { #define REC_SIZE sizeof(struct pstore_ftrace_record) +static void free_pstore_private(struct pstore_private *private) +{ + if (!private) + return; + kfree(private->buf); + kfree(private); +} + static void *pstore_ftrace_seq_start(struct seq_file *s, loff_t *pos) { struct pstore_private *ps = s->private; @@ -105,7 +113,7 @@ static int pstore_ftrace_seq_show(struct seq_file *s, void *v) { struct pstore_private *ps = s->private; struct pstore_ftrace_seq_data *data = v; - struct pstore_ftrace_record *rec = (void *)(ps->data + data->off); + struct pstore_ftrace_record *rec = (void *)(ps->buf + data->off); seq_printf(s, "CPU:%d ts:%llu %08lx %08lx %pf <- %pF\n", pstore_ftrace_decode_cpu(rec), @@ -143,7 +151,7 @@ static ssize_t pstore_file_read(struct file *file, char __user *userbuf, if (ps->type == PSTORE_TYPE_FTRACE) return seq_read(file, userbuf, count, ppos); - return simple_read_from_buffer(userbuf, count, ppos, ps->data, ps->size); + return simple_read_from_buffer(userbuf, count, ppos, ps->buf, ps->size); } static int pstore_file_open(struct inode *inode, struct file *file) @@ -221,7 +229,7 @@ static void pstore_evict_inode(struct inode *inode) spin_lock_irqsave(&allpstore_lock, flags); list_del(&p->list); spin_unlock_irqrestore(&allpstore_lock, flags); - kfree(p); + free_pstore_private(p); } } @@ -332,7 +340,7 @@ int pstore_mkfile(struct pstore_record *record) goto fail; inode->i_mode = S_IFREG | 0444; inode->i_fop = &pstore_file_operations; - private = kmalloc(sizeof *private + size, GFP_KERNEL); + private = kzalloc(sizeof(*private), GFP_KERNEL); if (!private) goto fail_alloc; private->type = record->type; @@ -394,7 +402,7 @@ int pstore_mkfile(struct pstore_record *record) if (!dentry) goto fail_lockedalloc; - memcpy(private->data, record->buf, size); + private->buf = record->buf; inode->i_size = private->size = size; inode->i_private = private; @@ -414,7 +422,7 @@ int pstore_mkfile(struct pstore_record *record) fail_lockedalloc: inode_unlock(d_inode(root)); - kfree(private); + free_pstore_private(private); fail_alloc: iput(inode); diff --git a/fs/pstore/platform.c b/fs/pstore/platform.c index c0d401e732e6..d897e2f11b6a 100644 --- a/fs/pstore/platform.c +++ b/fs/pstore/platform.c @@ -828,14 +828,22 @@ void pstore_get_records(int quiet) if (psi->open && psi->open(psi)) goto out; + /* + * Backend callback read() allocates record.buf. decompress_record() + * may reallocate record.buf. On success, pstore_mkfile() will keep + * the record.buf, so free it only on failure. + */ while ((record.size = psi->read(&record)) > 0) { decompress_record(&record); rc = pstore_mkfile(&record); + if (rc) { + /* pstore_mkfile() did not take buf, so free it. */ + kfree(record.buf); + if (rc != -EEXIST || !quiet) + failed++; + } - if (rc && (rc != -EEXIST || !quiet)) - failed++; - - kfree(record.buf); + /* Reset for next record. */ memset(&record, 0, sizeof(record)); record.psi = psi; }