From patchwork Thu May 23 02:51:11 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Scott Branden X-Patchwork-Id: 10956867 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 37195112C for ; Thu, 23 May 2019 02:51:43 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 1D1D226C9B for ; Thu, 23 May 2019 02:51:43 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 113BC27D29; Thu, 23 May 2019 02:51:43 +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=-8.0 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,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 70EFB26C9B for ; Thu, 23 May 2019 02:51:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729892AbfEWCvl (ORCPT ); Wed, 22 May 2019 22:51:41 -0400 Received: from mail-pg1-f195.google.com ([209.85.215.195]:42130 "EHLO mail-pg1-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729877AbfEWCv2 (ORCPT ); Wed, 22 May 2019 22:51:28 -0400 Received: by mail-pg1-f195.google.com with SMTP id e17so2156707pgo.9 for ; Wed, 22 May 2019 19:51:28 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=broadcom.com; s=google; h=from:to:cc:subject:date:message-id:in-reply-to:references; bh=IQeVd/84/xR4UF/8mxB5+jIJHDbqJkh066X1hA8pE4U=; b=eROfEuBNv8XrjbmYrwNaxcEgMqBNbDWE7LwFChWurrOGGhpYfYgyc6zd457U9DPvkb Y8hB8raBTgWJbw+wwXqYqrOUa0lPYk8CUxH51IvlP4C18qJRjDxzd93RXZSe/e0ickWL EVMembvBlMR6hyC9yPWP8H+oX3hRpB+ceX9Og= 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=IQeVd/84/xR4UF/8mxB5+jIJHDbqJkh066X1hA8pE4U=; b=Q+Hf3JkBYPBHkdzyyE/egiKdR9mx9OHoympG5lRWNl/V1iObBQhWT5Oz1wIs9iK2Ak NDG2cRD+/n8GcFv6v3vhisk4baYIZu3WCZKS023z2MWSjckLAg8tPU5AYGQtr4BYSq2e hMZf4fOFbyi4jgkUPhXXAQMAfy/vcPY0SCo1QjMff8A/aCjYNbFntkOYsKZuaLTH5Dj5 B3fWfQVxHxP8TFYooG6BvBBpr+Bo3sDmmb6oaRKs8+hWMW4NFVTXah18wbuvvyYxKsjx fKNqZXhireV4oMOUgJh16PNg58c4jarz4yuaFJslQrEOUKezCBT8wpb8efg/d0aa2hW3 EvwQ== X-Gm-Message-State: APjAAAXYUOKW8z48huVxR1ejaeHkKEtscJJNWioqaHxpWTxhqk310EO7 vGByZE9EVcEkBP0iwupnmwUcFw== X-Google-Smtp-Source: APXvYqzIwk+Yq92qpe20eEs6VVhu+ZObr2Z9NJbXovcghc1bax3W3UqwKw8rX8AX7Z5paltFAk3KSA== X-Received: by 2002:a62:1844:: with SMTP id 65mr87911224pfy.127.1558579887745; Wed, 22 May 2019 19:51:27 -0700 (PDT) Received: from lbrmn-lnxub113.broadcom.net ([192.19.228.250]) by smtp.gmail.com with ESMTPSA id q19sm42812174pff.96.2019.05.22.19.51.26 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Wed, 22 May 2019 19:51:27 -0700 (PDT) From: Scott Branden To: Luis Chamberlain , Greg Kroah-Hartman , Andy Gross , David Brown , Alexander Viro Cc: "Rafael J . Wysocki" , linux-kernel@vger.kernel.org, linux-arm-msm@vger.kernel.org, linux-fsdevel@vger.kernel.org, BCM Kernel Feedback , Olof Johansson , Scott Branden Subject: [PATCH 1/3] fs: introduce kernel_pread_file* support Date: Wed, 22 May 2019 19:51:11 -0700 Message-Id: <20190523025113.4605-2-scott.branden@broadcom.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20190523025113.4605-1-scott.branden@broadcom.com> References: <20190523025113.4605-1-scott.branden@broadcom.com> Sender: linux-arm-msm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-arm-msm@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Add kernel_pread_file* support to kernel to allow for partial read of files with an offset into the file. Existing kernel_read_file functions call new kernel_pread_file functions with offset=0 and flags=KERNEL_PREAD_FLAG_WHOLE. Signed-off-by: Scott Branden --- fs/exec.c | 77 ++++++++++++++++++++++++++++++++++++---------- include/linux/fs.h | 15 +++++++++ 2 files changed, 75 insertions(+), 17 deletions(-) diff --git a/fs/exec.c b/fs/exec.c index d88584ebf07f..ba56450acfb3 100644 --- a/fs/exec.c +++ b/fs/exec.c @@ -892,10 +892,14 @@ struct file *open_exec(const char *name) } EXPORT_SYMBOL(open_exec); -int kernel_read_file(struct file *file, void **buf, loff_t *size, - loff_t max_size, enum kernel_read_file_id id) -{ - loff_t i_size, pos; +int kernel_pread_file(struct file *file, void **buf, loff_t *size, + loff_t pos, loff_t max_size, unsigned int flags, + enum kernel_read_file_id id) +{ + loff_t alloc_size; + loff_t buf_pos; + loff_t read_end; + loff_t i_size; ssize_t bytes = 0; int ret; @@ -915,21 +919,31 @@ int kernel_read_file(struct file *file, void **buf, loff_t *size, ret = -EINVAL; goto out; } - if (i_size > SIZE_MAX || (max_size > 0 && i_size > max_size)) { + + /* Default read to end of file */ + read_end = i_size; + + /* Allow reading partial portion of file */ + if ((flags & KERNEL_PREAD_FLAG_PART) && + (i_size > (pos + max_size))) + read_end = pos + max_size; + + alloc_size = read_end - pos; + if (i_size > SIZE_MAX || (max_size > 0 && alloc_size > max_size)) { ret = -EFBIG; goto out; } if (id != READING_FIRMWARE_PREALLOC_BUFFER) - *buf = vmalloc(i_size); + *buf = vmalloc(alloc_size); if (!*buf) { ret = -ENOMEM; goto out; } - pos = 0; - while (pos < i_size) { - bytes = kernel_read(file, *buf + pos, i_size - pos, &pos); + buf_pos = 0; + while (pos < read_end) { + bytes = kernel_read(file, *buf + buf_pos, read_end - pos, &pos); if (bytes < 0) { ret = bytes; goto out_free; @@ -937,14 +951,16 @@ int kernel_read_file(struct file *file, void **buf, loff_t *size, if (bytes == 0) break; + + buf_pos += bytes; } - if (pos != i_size) { + if (pos != read_end) { ret = -EIO; goto out_free; } - ret = security_kernel_post_read_file(file, *buf, i_size, id); + ret = security_kernel_post_read_file(file, *buf, alloc_size, id); if (!ret) *size = pos; @@ -960,10 +976,20 @@ int kernel_read_file(struct file *file, void **buf, loff_t *size, allow_write_access(file); return ret; } +EXPORT_SYMBOL_GPL(kernel_pread_file); + +int kernel_read_file(struct file *file, void **buf, loff_t *size, + loff_t max_size, enum kernel_read_file_id id) +{ + return kernel_pread_file(file, buf, size, 0, max_size, + KERNEL_PREAD_FLAG_WHOLE, id); +} EXPORT_SYMBOL_GPL(kernel_read_file); -int kernel_read_file_from_path(const char *path, void **buf, loff_t *size, - loff_t max_size, enum kernel_read_file_id id) +int kernel_pread_file_from_path(const char *path, void **buf, + loff_t *size, loff_t pos, + loff_t max_size, unsigned int flags, + enum kernel_read_file_id id) { struct file *file; int ret; @@ -975,14 +1001,23 @@ int kernel_read_file_from_path(const char *path, void **buf, loff_t *size, if (IS_ERR(file)) return PTR_ERR(file); - ret = kernel_read_file(file, buf, size, max_size, id); + ret = kernel_pread_file(file, buf, size, pos, max_size, flags, id); fput(file); return ret; } +EXPORT_SYMBOL_GPL(kernel_pread_file_from_path); + +int kernel_read_file_from_path(const char *path, void **buf, loff_t *size, + loff_t max_size, enum kernel_read_file_id id) +{ + return kernel_pread_file_from_path(path, buf, size, 0, max_size, + KERNEL_PREAD_FLAG_WHOLE, id); +} EXPORT_SYMBOL_GPL(kernel_read_file_from_path); -int kernel_read_file_from_fd(int fd, void **buf, loff_t *size, loff_t max_size, - enum kernel_read_file_id id) +int kernel_pread_file_from_fd(int fd, void **buf, loff_t *size, loff_t pos, + loff_t max_size, unsigned int flags, + enum kernel_read_file_id id) { struct fd f = fdget(fd); int ret = -EBADF; @@ -990,11 +1025,19 @@ int kernel_read_file_from_fd(int fd, void **buf, loff_t *size, loff_t max_size, if (!f.file) goto out; - ret = kernel_read_file(f.file, buf, size, max_size, id); + ret = kernel_pread_file(f.file, buf, size, pos, max_size, flags, id); out: fdput(f); return ret; } +EXPORT_SYMBOL_GPL(kernel_pread_file_from_fd); + +int kernel_read_file_from_fd(int fd, void **buf, loff_t *size, loff_t max_size, + enum kernel_read_file_id id) +{ + return kernel_pread_file_from_fd(fd, buf, size, 0, max_size, + KERNEL_PREAD_FLAG_WHOLE, id); +} EXPORT_SYMBOL_GPL(kernel_read_file_from_fd); ssize_t read_code(struct file *file, unsigned long addr, loff_t pos, size_t len) diff --git a/include/linux/fs.h b/include/linux/fs.h index f7fdfe93e25d..033a3e7f0015 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -2942,10 +2942,25 @@ static inline const char *kernel_read_file_id_str(enum kernel_read_file_id id) return kernel_read_file_str[id]; } +/* Flags used by kernel_pread_file functions */ +#define KERNEL_PREAD_FLAG_WHOLE 0x0000 /* Only Allow reading of whole file */ +#define KERNEL_PREAD_FLAG_PART 0x0001 /* Allow reading part of file */ + +extern int kernel_pread_file(struct file *file, void **buf, loff_t *size, + loff_t pos, loff_t max_size, unsigned int flags, + enum kernel_read_file_id id); extern int kernel_read_file(struct file *, void **, loff_t *, loff_t, enum kernel_read_file_id); +extern int kernel_pread_file_from_path(const char *path, void **buf, + loff_t *size, loff_t pos, + loff_t max_size, unsigned int flags, + enum kernel_read_file_id id); extern int kernel_read_file_from_path(const char *, void **, loff_t *, loff_t, enum kernel_read_file_id); +extern int kernel_pread_file_from_fd(int fd, void **buf, loff_t *size, + loff_t pos, loff_t max_size, + unsigned int flags, + enum kernel_read_file_id id); extern int kernel_read_file_from_fd(int, void **, loff_t *, loff_t, enum kernel_read_file_id); extern ssize_t kernel_read(struct file *, void *, size_t, loff_t *);