| lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
|
Open Source and information security mailing list archives
| ||
|
Message-ID: <87veh6z030.fsf@sw.ru>
Date: Mon, 12 Mar 2007 23:19:31 +0300
From: Dmitriy Monakhov <dmonakhov@...nvz.org>
To: linux-kernel@...r.kernel.org
CC: Nick Piggin <npiggin@...e.de>, devel@...nvz.org, xfs@....sgi.com,
linux-ntfs-dev@...ts.sourceforge.net
Subject: [PATCH 1/2] mm: move common segment checks to separate helper function (v7)
Changes against v6
- remove duplicated code from xfs,ntfs
- export generic_segment_checks, because it used by xfs,nfs now.
- change arguments initialization pocily according to Nick's comments.
Tested with: ltp readv/writev tests
Signed-off-by: Monakhov Dmitriy <dmonakhov@...nvz.org>
---
fs/ntfs/file.c | 21 ++---------
fs/xfs/linux-2.6/xfs_lrw.c | 22 ++----------
include/linux/fs.h | 3 ++
mm/filemap.c | 83 ++++++++++++++++++++++++-------------------
4 files changed, 55 insertions(+), 74 deletions(-)
diff --git a/fs/ntfs/file.c b/fs/ntfs/file.c
index dbbac55..621de36 100644
--- a/fs/ntfs/file.c
+++ b/fs/ntfs/file.c
@@ -2129,28 +2129,13 @@ static ssize_t ntfs_file_aio_write_nolock(struct kiocb *iocb,
struct address_space *mapping = file->f_mapping;
struct inode *inode = mapping->host;
loff_t pos;
- unsigned long seg;
size_t count; /* after file limit checks */
ssize_t written, err;
count = 0;
- for (seg = 0; seg < nr_segs; seg++) {
- const struct iovec *iv = &iov[seg];
- /*
- * If any segment has a negative length, or the cumulative
- * length ever wraps negative then return -EINVAL.
- */
- count += iv->iov_len;
- if (unlikely((ssize_t)(count|iv->iov_len) < 0))
- return -EINVAL;
- if (access_ok(VERIFY_READ, iv->iov_base, iv->iov_len))
- continue;
- if (!seg)
- return -EFAULT;
- nr_segs = seg;
- count -= iv->iov_len; /* This segment is no good */
- break;
- }
+ err = generic_segment_checks(iov, &nr_segs, &count, VERIFY_READ);
+ if (err)
+ return err;
pos = *ppos;
vfs_check_frozen(inode->i_sb, SB_FREEZE_WRITE);
/* We can write back this queue in page reclaim. */
diff --git a/fs/xfs/linux-2.6/xfs_lrw.c b/fs/xfs/linux-2.6/xfs_lrw.c
index ff8d64e..558076d 100644
--- a/fs/xfs/linux-2.6/xfs_lrw.c
+++ b/fs/xfs/linux-2.6/xfs_lrw.c
@@ -639,7 +639,6 @@ xfs_write(
xfs_fsize_t isize, new_size;
xfs_iocore_t *io;
bhv_vnode_t *vp;
- unsigned long seg;
int iolock;
int eventsent = 0;
bhv_vrwlock_t locktype;
@@ -652,24 +651,9 @@ xfs_write(
vp = BHV_TO_VNODE(bdp);
xip = XFS_BHVTOI(bdp);
- for (seg = 0; seg < segs; seg++) {
- const struct iovec *iv = &iovp[seg];
-
- /*
- * If any segment has a negative length, or the cumulative
- * length ever wraps negative then return -EINVAL.
- */
- ocount += iv->iov_len;
- if (unlikely((ssize_t)(ocount|iv->iov_len) < 0))
- return -EINVAL;
- if (access_ok(VERIFY_READ, iv->iov_base, iv->iov_len))
- continue;
- if (seg == 0)
- return -EFAULT;
- segs = seg;
- ocount -= iv->iov_len; /* This segment is no good */
- break;
- }
+ error = generic_segment_checks(iovp, &segs, &ocount, VERIFY_READ);
+ if (error)
+ return error;
count = ocount;
pos = *offset;
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 6a3d22e..3b99450 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -1778,6 +1778,9 @@ extern ssize_t generic_file_sendfile(struct file *, loff_t *, size_t, read_actor
extern void do_generic_mapping_read(struct address_space *mapping,
struct file_ra_state *, struct file *,
loff_t *, read_descriptor_t *, read_actor_t);
+extern int generic_segment_checks(const struct iovec *iov,
+ unsigned long *nr_segs, size_t *count,
+ unsigned long access_flags);
/* fs/splice.c */
extern ssize_t generic_file_splice_read(struct file *, loff_t *,
diff --git a/mm/filemap.c b/mm/filemap.c
index 8e1849a..8bd1ea4 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -1159,6 +1159,46 @@ success:
return size;
}
+/*
+ * Performs necessary checks before doing a write
+ * @iov: io vector request
+ * @nr_segs: number of segments in the iovec
+ * @count: number of bytes to write
+ * @access_flags: type of access: %VERIFY_READ or %VERIFY_WRITE
+ *
+ * Adjust number of segments and amount of bytes to write (nr_segs should be
+ * properly initialized first). Returns appropriate error code that caller
+ * should return or zero in case that write should be allowed.
+ */
+int generic_segment_checks(const struct iovec *iov,
+ unsigned long *nr_segs, size_t *count,
+ unsigned long access_flags)
+{
+ unsigned long seg;
+ size_t cnt = 0;
+ for (seg = 0; seg < *nr_segs; seg++) {
+ const struct iovec *iv = &iov[seg];
+
+ /*
+ * If any segment has a negative length, or the cumulative
+ * length ever wraps negative then return -EINVAL.
+ */
+ cnt += iv->iov_len;
+ if (unlikely((ssize_t)(cnt|iv->iov_len) < 0))
+ return -EINVAL;
+ if (access_ok(access_flags, iv->iov_base, iv->iov_len))
+ continue;
+ if (seg == 0)
+ return -EFAULT;
+ *nr_segs = seg;
+ cnt -= iv->iov_len; /* This segment is no good */
+ break;
+ }
+ *count = cnt;
+ return 0;
+}
+EXPORT_SYMBOL(generic_segment_checks);
+
/**
* generic_file_aio_read - generic filesystem read routine
* @iocb: kernel I/O control block
@@ -1180,24 +1220,9 @@ generic_file_aio_read(struct kiocb *iocb, const struct iovec *iov,
loff_t *ppos = &iocb->ki_pos;
count = 0;
- for (seg = 0; seg < nr_segs; seg++) {
- const struct iovec *iv = &iov[seg];
-
- /*
- * If any segment has a negative length, or the cumulative
- * length ever wraps negative then return -EINVAL.
- */
- count += iv->iov_len;
- if (unlikely((ssize_t)(count|iv->iov_len) < 0))
- return -EINVAL;
- if (access_ok(VERIFY_WRITE, iv->iov_base, iv->iov_len))
- continue;
- if (seg == 0)
- return -EFAULT;
- nr_segs = seg;
- count -= iv->iov_len; /* This segment is no good */
- break;
- }
+ retval = generic_segment_checks(iov, &nr_segs, &count, VERIFY_WRITE);
+ if (retval)
+ return retval;
/* coalesce the iovecs and go direct-to-BIO for O_DIRECT */
if (filp->f_flags & O_DIRECT) {
@@ -2094,30 +2119,14 @@ __generic_file_aio_write_nolock(struct kiocb *iocb, const struct iovec *iov,
size_t ocount; /* original count */
size_t count; /* after file limit checks */
struct inode *inode = mapping->host;
- unsigned long seg;
loff_t pos;
ssize_t written;
ssize_t err;
ocount = 0;
- for (seg = 0; seg < nr_segs; seg++) {
- const struct iovec *iv = &iov[seg];
-
- /*
- * If any segment has a negative length, or the cumulative
- * length ever wraps negative then return -EINVAL.
- */
- ocount += iv->iov_len;
- if (unlikely((ssize_t)(ocount|iv->iov_len) < 0))
- return -EINVAL;
- if (access_ok(VERIFY_READ, iv->iov_base, iv->iov_len))
- continue;
- if (seg == 0)
- return -EFAULT;
- nr_segs = seg;
- ocount -= iv->iov_len; /* This segment is no good */
- break;
- }
+ err = generic_segment_checks(iov, &nr_segs, &ocount, VERIFY_READ);
+ if (err)
+ return err;
count = ocount;
pos = *ppos;
--
1.5.0.1
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
Powered by blists - more mailing lists