From patchwork Wed Apr 29 17:09:08 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Scott Branden X-Patchwork-Id: 11517943 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 708FF112C for ; Wed, 29 Apr 2020 17:09:37 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 53E9720B1F for ; Wed, 29 Apr 2020 17:09:37 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=broadcom.com header.i=@broadcom.com header.b="ETPfZUIP" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727041AbgD2RJg (ORCPT ); Wed, 29 Apr 2020 13:09:36 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:58322 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1726869AbgD2RJg (ORCPT ); Wed, 29 Apr 2020 13:09:36 -0400 Received: from mail-pl1-x643.google.com (mail-pl1-x643.google.com [IPv6:2607:f8b0:4864:20::643]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 35DF8C03C1AE for ; Wed, 29 Apr 2020 10:09:36 -0700 (PDT) Received: by mail-pl1-x643.google.com with SMTP id z6so1053553plk.10 for ; Wed, 29 Apr 2020 10:09:36 -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=fgv/fcDXTDFVmuGXIXdyLKuOfq35HUlELweudxMRWMs=; b=ETPfZUIPDFks97PzHy9SYycnRBj3zPyGyr2HWelFElXhwDxKWHijOKl4DlKhU2Ynmn tD+GpNljiU5PLxr7nZ5gldB6FBUUSQHUlKAvc7f2qc4zFdxARH7Kx6n3m5gCSGfb+pH1 WSqJ95S522e+I9+aKToovZW41hBQY/H9LsAQs= 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=fgv/fcDXTDFVmuGXIXdyLKuOfq35HUlELweudxMRWMs=; b=puX/AuH8IsRB7vTyfSvfBaeCRSGm3+ySHMDqQvdb5A825jdTfiZSCGqKRn4ZqjpwEM 7WFZ6V0PomhjJW++3h3D4y0qICjffBT2R6FMEFAi/iFv2lRbt7SBIBGFZIsh+DkI43lm VM1KrAb4WmmzZbBVfxoCnPXn6FVburufiU1sNfYyFLWcIJGHhmD3qOAUeLTblq+UxcQn yp76UKrvAqYTUFnpEgnI6zo8p7SrjhOxlpGaFYy9U8masysDSUk2ED1ACsNtXNipjwjj rS6vbfs7qBS57W0o65QTQR2OiX8BcxbXlOq3Q7JwLeHxoGdaJ3gv1f+DcHfpMq0IXD4G FCxA== X-Gm-Message-State: AGi0PubI+DaAGxPafM38wfTsoqZC2VHPiqI9+uUn7LYanap8FCM7kDeC zcGdYvcXIVyPNgvRjYxZaY6e4Q== X-Google-Smtp-Source: APiQypJ361WVRLBikA65VnfhrEKyLsAsecq7btVruT5cPl6M4Ul7pMqwXzyDpu50Q/NhpZZ8B/STzQ== X-Received: by 2002:a17:902:6949:: with SMTP id k9mr35236624plt.211.1588180174165; Wed, 29 Apr 2020 10:09:34 -0700 (PDT) Received: from lbrmn-lnxub113.broadcom.net ([192.19.228.250]) by smtp.gmail.com with ESMTPSA id y63sm1574456pfg.138.2020.04.29.10.09.31 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 29 Apr 2020 10:09:33 -0700 (PDT) From: Scott Branden To: Luis Chamberlain , Greg Kroah-Hartman , David Brown , Alexander Viro , Shuah Khan , bjorn.andersson@linaro.org, Shuah Khan , Arnd Bergmann 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 , Andrew Morton , Dan Carpenter , Colin Ian King , Kees Cook , Takashi Iwai , linux-kselftest@vger.kernel.org, Andy Gross , Scott Branden Subject: [PATCH v4 1/7] fs: introduce kernel_pread_file* support Date: Wed, 29 Apr 2020 10:09:08 -0700 Message-Id: <20200429170914.30976-2-scott.branden@broadcom.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20200429170914.30976-1-scott.branden@broadcom.com> References: <20200429170914.30976-1-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 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 | 96 ++++++++++++++++++++++++++++++++++++---------- include/linux/fs.h | 20 ++++++++++ 2 files changed, 95 insertions(+), 21 deletions(-) diff --git a/fs/exec.c b/fs/exec.c index 06b4c550af5d..cfab212fab9d 100644 --- a/fs/exec.c +++ b/fs/exec.c @@ -896,10 +896,14 @@ 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; @@ -919,21 +923,31 @@ 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; @@ -941,14 +955,16 @@ 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; @@ -964,10 +980,20 @@ 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; @@ -979,15 +1005,25 @@ 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_path_initns(const char *path, void **buf, - loff_t *size, loff_t max_size, - enum kernel_read_file_id id) +extern int kernel_pread_file_from_path_initns(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; struct path root; @@ -1005,14 +1041,24 @@ int kernel_read_file_from_path_initns(const char *path, void **buf, 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_initns); + +int kernel_read_file_from_path_initns(const char *path, void **buf, + loff_t *size, loff_t max_size, + enum kernel_read_file_id id) +{ + return kernel_pread_file_from_path_initns(path, buf, size, 0, max_size, + KERNEL_PREAD_FLAG_WHOLE, id); +} EXPORT_SYMBOL_GPL(kernel_read_file_from_path_initns); -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; @@ -1020,11 +1066,19 @@ 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 4f6f59b4f22a..03441fbcad6c 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -3014,12 +3014,32 @@ 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_path_initns(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_initns(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 *);