From: Christoph Hellwig <hch@lst.de>
To: Al Viro <viro@zeniv.linux.org.uk>
Cc: linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org,
linux-security-module@vger.kernel.org
Subject: [PATCH 09/11] fs: implement kernel_read using __kernel_read
Date: Fri, 8 May 2020 11:22:20 +0200 [thread overview]
Message-ID: <20200508092222.2097-10-hch@lst.de> (raw)
In-Reply-To: <20200508092222.2097-1-hch@lst.de>
Consolidate the two in-kernel read helpers to make upcoming changes
easier. The only difference are the missing call to rw_verify_area
in kernel_read, and an access_ok check that doesn't make sense for
kernel buffers to start with.
Signed-off-by: Christoph Hellwig <hch@lst.de>
---
fs/read_write.c | 13 +++++--------
1 file changed, 5 insertions(+), 8 deletions(-)
diff --git a/fs/read_write.c b/fs/read_write.c
index 93f5724b4837d..0ffbed5fd8136 100644
--- a/fs/read_write.c
+++ b/fs/read_write.c
@@ -453,15 +453,12 @@ ssize_t __kernel_read(struct file *file, void *buf, size_t count, loff_t *pos)
ssize_t kernel_read(struct file *file, void *buf, size_t count, loff_t *pos)
{
- mm_segment_t old_fs;
- ssize_t result;
+ ssize_t ret;
- old_fs = get_fs();
- set_fs(KERNEL_DS);
- /* The cast to a user pointer is valid due to the set_fs() */
- result = vfs_read(file, (void __user *)buf, count, pos);
- set_fs(old_fs);
- return result;
+ ret = rw_verify_area(READ, file, pos, count);
+ if (ret)
+ return ret;
+ return __kernel_read(file, buf, count, pos);
}
EXPORT_SYMBOL(kernel_read);
--
2.26.2
next prev parent reply other threads:[~2020-05-08 9:22 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-05-08 9:22 clean up kernel_{read,write} & friends Christoph Hellwig
2020-05-08 9:22 ` [PATCH 01/11] fs: call file_{start,end}_write from __kernel_write Christoph Hellwig
2020-05-08 9:22 ` [PATCH 02/11] fs: check FMODE_WRITE in __kernel_write Christoph Hellwig
2020-05-08 9:22 ` [PATCH 03/11] fs: remove the call_{read,write}_iter functions Christoph Hellwig
2020-05-08 9:22 ` [PATCH 04/11] fs: implement kernel_write using __kernel_write Christoph Hellwig
2020-05-08 9:22 ` [PATCH 05/11] fs: remove __vfs_write Christoph Hellwig
2020-05-08 9:22 ` [PATCH 06/11] fs: don't change the address limit for ->write_iter in __kernel_write Christoph Hellwig
2020-05-08 9:22 ` [PATCH 07/11] fs: add a __kernel_read helper Christoph Hellwig
2020-05-08 9:22 ` [PATCH 08/11] integrity/ima: switch to using __kernel_read Christoph Hellwig
2020-05-08 9:22 ` Christoph Hellwig [this message]
2020-05-08 9:22 ` [PATCH 10/11] fs: remove __vfs_read Christoph Hellwig
2020-05-08 15:45 ` Ira Weiny
2020-05-08 15:46 ` Christoph Hellwig
2020-05-08 9:22 ` [PATCH 11/11] fs: don't change the address limit for ->read_iter in __kernel_read Christoph Hellwig
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