From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-9.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 309A7C282DD for ; Thu, 23 May 2019 02:51:43 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id D5AE3217D4 for ; Thu, 23 May 2019 02:51:42 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=broadcom.com header.i=@broadcom.com header.b="eROfEuBN" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729898AbfEWCv2 (ORCPT ); Wed, 22 May 2019 22:51:28 -0400 Received: from mail-pg1-f195.google.com ([209.85.215.195]:45994 "EHLO mail-pg1-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729762AbfEWCv2 (ORCPT ); Wed, 22 May 2019 22:51:28 -0400 Received: by mail-pg1-f195.google.com with SMTP id i21so2290131pgi.12 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=FSOjAU3mXg6WnnPfq00BG2VBGVadpauY+ufPG6/s0C97jrWCNlWrz6UpfVDQ7eT3oK rhBXHnofR/DZFiuPGLLrO4u8tPrUNoG74owjaPwpjwPGpVVNULYajMiRL5ImbD/As42F Xqxvci4Ez3Dp14eIdkzbhDhTtcNkN/y6I5O1Ge/fWO3KQwuMKno/K780y8S3wC6NqyR/ /piBH+/5i6Z/13f4h7UvUvMhQEF5kE2GY9nU5bdwhwaedqjKPrgFBbNemQJdfLMQpGU0 p6PJTZ/k8WWNbQ2/I/oFr9P5yybeVib7dYIQGjVsMoglCcOKrqthgIWaLElpZxdHlicr sJFw== X-Gm-Message-State: APjAAAXV465F9zU23b0SiN4Li2DMMTwMOjDQMAx0RcUC0dY5hwAbSF8d KIpnDSJ0MioZvFyhN1+Dx71/HA== 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-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org 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 *); -- 2.17.1