From: Christoph Hellwig <hch@lst.de>
To: Al Viro <viro@zeniv.linux.org.uk>
Cc: Linus Torvalds <torvalds@linux-foundation.org>,
Ian Kent <raven@themaw.net>, David Howells <dhowells@redhat.com>,
linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org,
linux-security-module@vger.kernel.org,
netfilter-devel@vger.kernel.org
Subject: [PATCH 11/14] fs: implement kernel_read using __kernel_read
Date: Wed, 24 Jun 2020 18:13:32 +0200 [thread overview]
Message-ID: <20200624161335.1810359-12-hch@lst.de> (raw)
In-Reply-To: <20200624161335.1810359-1-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 cc8e0b4f3cd697..a0a0b5d1d9249c 100644
--- a/fs/read_write.c
+++ b/fs/read_write.c
@@ -455,15 +455,12 @@ 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:[~2020-06-24 16:14 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-06-24 16:13 clean up kernel_{read,write} & friends v5 Christoph Hellwig
2020-06-24 16:13 ` [PATCH 01/14] cachefiles: switch to kernel_write Christoph Hellwig
2020-06-24 16:13 ` [PATCH 02/14] autofs: " Christoph Hellwig
2020-06-24 16:13 ` [PATCH 03/14] bpfilter: " Christoph Hellwig
2020-06-24 16:13 ` [PATCH 04/14] fs: unexport __kernel_write Christoph Hellwig
2020-06-24 16:13 ` [PATCH 05/14] fs: check FMODE_WRITE in __kernel_write Christoph Hellwig
2020-06-24 16:13 ` [PATCH 06/14] fs: implement kernel_write using __kernel_write Christoph Hellwig
2020-06-24 16:13 ` [PATCH 07/14] fs: remove __vfs_write Christoph Hellwig
2020-06-24 16:13 ` [PATCH 08/14] fs: don't change the address limit for ->write_iter in __kernel_write Christoph Hellwig
2020-06-24 16:13 ` [PATCH 09/14] fs: add a __kernel_read helper Christoph Hellwig
2020-06-24 16:13 ` [PATCH 10/14] integrity/ima: switch to using __kernel_read Christoph Hellwig
2020-06-24 16:13 ` Christoph Hellwig [this message]
2020-06-24 16:13 ` [PATCH 12/14] fs: remove __vfs_read Christoph Hellwig
2020-06-24 16:13 ` [PATCH 13/14] fs: implement default_file_splice_read using __kernel_read Christoph Hellwig
[not found] ` <20200701091943.GC3874@shao2-debian>
2020-07-01 12:13 ` [fs] 140402bab8: stress-ng.splice.ops_per_sec -100.0% regression Christoph Hellwig
2020-07-01 20:32 ` Linus Torvalds
2020-06-24 16:13 ` [PATCH 14/14] fs: don't change the address limit for ->read_iter in __kernel_read Christoph Hellwig
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