ich777/linux_media
1
0
Fork 0
mirror of https://github.com/tbsdtv/linux_media.git synced 2025-07-23 20:51:03 +02:00
Code Issues Packages Projects Releases Wiki Activity

file: Factor files_lookup_fd_locked out of fcheck_files

Browse Source 
To make it easy to tell where files->file_lock protection is being
used when looking up a file create files_lookup_fd_locked.  Only allow
this function to be called with the file_lock held.

Update the callers of fcheck and fcheck_files that are called with the
files->file_lock held to call files_lookup_fd_locked instead.

Hopefully this makes it easier to quickly understand what is going on.

The need for better names became apparent in the last round of
discussion of this set of changes[1].

[1] https://lkml.kernel.org/r/CAHk-=wj8BQbgJFLa+J0e=iT-1qpmCRTbPAJ8gd6MJQ=kbRPqyQ@mail.gmail.com
Link: https://lkml.kernel.org/r/20201120231441.29911-8-ebiederm@xmission.com
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
This commit is contained in:
Eric W. Biederman
2020-11-20 17:14:25 -06:00
parent bebf684bf3
commit 120ce2b0cd
4 changed files with 17 additions and 8 deletions
Download Patch File Download Diff File Expand all files Collapse all files

7
include/linux/fdtable.h
View File

@@ -91,6 +91,13 @@ static inline struct file *files_lookup_fd_raw(struct files_struct *files, unsig
return NULL;
}
static inline struct file *files_lookup_fd_locked(struct files_struct *files, unsigned int fd)
{
RCU_LOCKDEP_WARN(!lockdep_is_held(&files->file_lock),
"suspicious rcu_dereference_check() usage");
return files_lookup_fd_raw(files, fd);
}
static inline struct file *fcheck_files(struct files_struct *files, unsigned int fd)
{
RCU_LOCKDEP_WARN(!rcu_read_lock_held() &&