All of lore.kernel.org
 help / color / mirror / Atom feed
From: Scott Branden <scott.branden@broadcom.com>
To: Luis Chamberlain <mcgrof@kernel.org>,
	Wolfram Sang <wsa@kernel.org>,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	David Brown <david.brown@linaro.org>,
	Alexander Viro <viro@zeniv.linux.org.uk>,
	Shuah Khan <shuah@kernel.org>,
	bjorn.andersson@linaro.org,
	Shuah Khan <skhan@linuxfoundation.org>,
	Arnd Bergmann <arnd@arndb.de>
Cc: Mimi Zohar <zohar@linux.ibm.com>,
	"Rafael J . Wysocki" <rafael@kernel.org>,
	linux-kernel@vger.kernel.org, linux-arm-msm@vger.kernel.org,
	linux-fsdevel@vger.kernel.org,
	BCM Kernel Feedback <bcm-kernel-feedback-list@broadcom.com>,
	Olof Johansson <olof@lixom.net>,
	Andrew Morton <akpm@linux-foundation.org>,
	Dan Carpenter <dan.carpenter@oracle.com>,
	Colin Ian King <colin.king@canonical.com>,
	Kees Cook <keescook@chromium.org>, Takashi Iwai <tiwai@suse.de>,
	linux-kselftest@vger.kernel.org, Andy Gross <agross@kernel.org>,
	linux-integrity@vger.kernel.org,
	linux-security-module@vger.kernel.org,
	Scott Branden <scott.branden@broadcom.com>
Subject: [PATCH v8 1/8] fs: introduce kernel_pread_file* support
Date: Tue,  9 Jun 2020 15:56:49 -0700	[thread overview]
Message-ID: <20200609225656.18663-2-scott.branden@broadcom.com> (raw)
In-Reply-To: <20200609225656.18663-1-scott.branden@broadcom.com>

Add kernel_pread_file* support to kernel to allow for partial read
of files with an offset into the file.

Signed-off-by: Scott Branden <scott.branden@broadcom.com>
---
 fs/exec.c          | 93 ++++++++++++++++++++++++++++++++++------------
 include/linux/fs.h | 15 ++++++++
 2 files changed, 85 insertions(+), 23 deletions(-)

diff --git a/fs/exec.c b/fs/exec.c
index 7b7cbb180785..c557b4b31d0f 100644
--- a/fs/exec.c
+++ b/fs/exec.c
@@ -927,10 +927,14 @@ 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 max_size, loff_t pos,
+		      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;
 
@@ -950,21 +954,32 @@ 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 ((id == READING_FIRMWARE_PARTIAL_READ) &&
+	    (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);
+	if ((id != READING_FIRMWARE_PARTIAL_READ) &&
+	    (id != READING_FIRMWARE_PREALLOC_BUFFER))
+		*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;
@@ -972,20 +987,23 @@ 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;
 
 out_free:
 	if (ret < 0) {
-		if (id != READING_FIRMWARE_PREALLOC_BUFFER) {
+		if ((id != READING_FIRMWARE_PARTIAL_READ) &&
+		    (id != READING_FIRMWARE_PREALLOC_BUFFER)) {
 			vfree(*buf);
 			*buf = NULL;
 		}
@@ -995,10 +1013,18 @@ int kernel_read_file(struct file *file, void **buf, loff_t *size,
 	allow_write_access(file);
 	return ret;
 }
+
+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, max_size, 0, 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 max_size, loff_t pos,
+				enum kernel_read_file_id id)
 {
 	struct file *file;
 	int ret;
@@ -1010,15 +1036,22 @@ 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, max_size, pos, id);
 	fput(file);
 	return ret;
 }
+
+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, max_size, 0, 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)
+int kernel_pread_file_from_path_initns(const char *path, void **buf,
+				       loff_t *size,
+				       loff_t max_size, loff_t pos,
+				       enum kernel_read_file_id id)
 {
 	struct file *file;
 	struct path root;
@@ -1036,14 +1069,22 @@ 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, max_size, pos, id);
 	fput(file);
 	return ret;
 }
+
+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, max_size, 0, 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 max_size, loff_t pos,
+			      enum kernel_read_file_id id)
 {
 	struct fd f = fdget(fd);
 	int ret = -EBADF;
@@ -1051,11 +1092,17 @@ 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, max_size, pos, id);
 out:
 	fdput(f);
 	return ret;
 }
+
+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, max_size, 0, id);
+}
 EXPORT_SYMBOL_GPL(kernel_read_file_from_fd);
 
 #if defined(CONFIG_HAVE_AOUT) || defined(CONFIG_BINFMT_FLAT) || \
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 951862b1211b..ab715559cf3c 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -3012,6 +3012,7 @@ extern int do_pipe_flags(int *, int);
 #define __kernel_read_file_id(id) \
 	id(UNKNOWN, unknown)		\
 	id(FIRMWARE, firmware)		\
+	id(FIRMWARE_PARTIAL_READ, firmware)	\
 	id(FIRMWARE_PREALLOC_BUFFER, firmware)	\
 	id(FIRMWARE_EFI_EMBEDDED, firmware)	\
 	id(MODULE, kernel-module)		\
@@ -3040,12 +3041,26 @@ static inline const char *kernel_read_file_id_str(enum kernel_read_file_id id)
 	return kernel_read_file_str[id];
 }
 
+int kernel_pread_file(struct file *file, void **buf, loff_t *size,
+		      loff_t pos, loff_t max_size,
+		      enum kernel_read_file_id id);
 extern int kernel_read_file(struct file *, void **, loff_t *, loff_t,
 			    enum kernel_read_file_id);
+int kernel_pread_file_from_path(const char *path, void **buf,
+				loff_t *size, loff_t pos,
+				loff_t max_size,
+				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);
+int kernel_pread_file_from_path_initns(const char *path, void **buf,
+				       loff_t *size, loff_t pos,
+				       loff_t max_size,
+				       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);
+int kernel_pread_file_from_fd(int fd, void **buf, loff_t *size,
+			      loff_t pos, loff_t max_size,
+			      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


  reply	other threads:[~2020-06-09 22:57 UTC|newest]

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-06-09 22:56 [PATCH v8 0/8] firmware: add request_partial_firmware_into_buf Scott Branden
2020-06-09 22:56 ` Scott Branden [this message]
2020-06-09 22:56 ` [PATCH v8 2/8] firmware: add offset to request_firmware_into_buf Scott Branden
2020-06-12  8:45   ` kernel test robot
2020-06-09 22:56 ` [PATCH v8 3/8] test_firmware: add partial read support for request_firmware_into_buf Scott Branden
2020-06-09 22:56 ` [PATCH v8 4/8] firmware: test partial file reads of request_firmware_into_buf Scott Branden
2020-06-09 22:56 ` [PATCH v8 5/8] bcm-vk: add bcm_vk UAPI Scott Branden
2020-06-09 22:56 ` [PATCH v8 6/8] misc: bcm-vk: add Broadcom VK driver Scott Branden
2020-06-09 22:56 ` [PATCH v8 7/8] MAINTAINERS: bcm-vk: add maintainer for Broadcom VK Driver Scott Branden
2020-06-09 22:56 ` [PATCH v8 8/8] ima: add FIRMWARE_PARTIAL_READ support Scott Branden

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20200609225656.18663-2-scott.branden@broadcom.com \
    --to=scott.branden@broadcom.com \
    --cc=agross@kernel.org \
    --cc=akpm@linux-foundation.org \
    --cc=arnd@arndb.de \
    --cc=bcm-kernel-feedback-list@broadcom.com \
    --cc=bjorn.andersson@linaro.org \
    --cc=colin.king@canonical.com \
    --cc=dan.carpenter@oracle.com \
    --cc=david.brown@linaro.org \
    --cc=gregkh@linuxfoundation.org \
    --cc=keescook@chromium.org \
    --cc=linux-arm-msm@vger.kernel.org \
    --cc=linux-fsdevel@vger.kernel.org \
    --cc=linux-integrity@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-kselftest@vger.kernel.org \
    --cc=linux-security-module@vger.kernel.org \
    --cc=mcgrof@kernel.org \
    --cc=olof@lixom.net \
    --cc=rafael@kernel.org \
    --cc=shuah@kernel.org \
    --cc=skhan@linuxfoundation.org \
    --cc=tiwai@suse.de \
    --cc=viro@zeniv.linux.org.uk \
    --cc=wsa@kernel.org \
    --cc=zohar@linux.ibm.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.