[PATCH v8 06/11] fs: make do_symlinkat() take struct filename

Dmitry Kadashev
2021-07-07T12:28:14Z

Pass in the struct filename pointers instead of the user string, for
uniformity with the recently converted do_mkdnodat(), do_unlinkat(),
do_renameat(), do_mkdirat().

Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Christian Brauner <christian.brauner@ubuntu.com>
Link: https://lore.kernel.org/io-uring/20210330071700.kpjoyp5zlni7uejm@wittgenstein/
Signed-off-by: Dmitry Kadashev <dkadashev@gmail.com>
Acked-by: Christian Brauner <christian.brauner@ubuntu.com>
---
fs/namei.c | 23 ++++++++++++-----------
1 file changed, 12 insertions(+), 11 deletions(-)

diff --git a/fs/namei.c b/fs/namei.c
index 0bc8ff637934..add984e4bfd0 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -4197,23 +4197,23 @@ int vfs_symlink(struct user_namespace *mnt_userns, struct inode *dir,
}
EXPORT_SYMBOL(vfs_symlink);

-static long do_symlinkat(const char __user *oldname, int newdfd,
- const char __user *newname)
+static long do_symlinkat(struct filename *from, int newdfd,
+ struct filename *to)
{
int error;
- struct filename *from;
struct dentry *dentry;
struct path path;
unsigned int lookup_flags = 0;

- from = getname(oldname);
- if (IS_ERR(from))
- return PTR_ERR(from);
+ if (IS_ERR(from)) {
+ error = PTR_ERR(from);
+ goto out_putnames;
+ }
retry:
- dentry = user_path_create(newdfd, newname, &path, lookup_flags);
+ dentry = __filename_create(newdfd, to, &path, lookup_flags);
error = PTR_ERR(dentry);
if (IS_ERR(dentry))
- goto out_putname;
+ goto out_putnames;

error = security_path_symlink(&path, dentry, from->name);
if (!error) {
@@ -4228,7 +4228,8 @@ static long do_symlinkat(const char __user *oldname, int newdfd,
lookup_flags |= LOOKUP_REVAL;
goto retry;
}
-out_putname:
+out_putnames:
+ putname(to);
putname(from);
return error;
}
@@ -4236,12 +4237,12 @@ static long do_symlinkat(const char __user *oldname, int newdfd,
SYSCALL_DEFINE3(symlinkat, const char __user *, oldname,
int, newdfd, const char __user *, newname)
{
- return do_symlinkat(oldname, newdfd, newname);
+ return do_symlinkat(getname(oldname), newdfd, getname(newname));
}

SYSCALL_DEFINE2(symlink, const char __user *, oldname, const char __user *, newname)
{
- return do_symlinkat(oldname, AT_FDCWD, newname);
+ return do_symlinkat(getname(oldname), AT_FDCWD, getname(newname));
}

/**
--
2.30.2