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author | Nicolai Stange <nicstange@gmail.com> | 2016-05-27 18:03:54 (GMT) |
---|---|---|
committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2016-06-18 04:24:41 (GMT) |
commit | 0fd9da9a979aecfb9df40dfb3304db2b16fa7e05 (patch) | |
tree | c99216b18739cb51be3698f9cd3dfba091631926 | |
parent | b1f656044a9936880d5a7460cd8784b2e124ab87 (diff) | |
download | linux-0fd9da9a979aecfb9df40dfb3304db2b16fa7e05.tar.xz |
staging/android: sync_debug: unproxify debugfs files' fops
Since commit 49d200deaa68 ("debugfs: prevent access to removed files'
private data"), a debugfs file's file_operations methods get proxied
through lifetime aware wrappers.
However, only a certain subset of the file_operations members is supported
by debugfs and ->compat_ioctl isn't among them -- it appears to be NULL
from the VFS layer's perspective.
This behaviour breaks the /sys/kernel/debug/sync/sw_sync file introduced
concurrently with commit a44eb74cd413 ("staging/android: move SW_SYNC_USER
to a debugfs file").
Since that file never gets removed, there is no file removal race and thus,
a lifetime checking proxy isn't needed.
Avoid the proxying for /sys/kernel/debug/sync/sw_sync by creating it via
debugfs_create_file_unsafe() rather than debugfs_create_file().
For consistency, do the same for /sys/kernel/debug/sync/info.
Fixes: 49d200deaa68 ("debugfs: prevent access to removed files' private data")
Fixes: a44eb74cd413 ("staging/android: move SW_SYNC_USER to a debugfs file")
Signed-off-by: Nicolai Stange <nicstange@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r-- | drivers/staging/android/sync_debug.c | 13 |
1 files changed, 9 insertions, 4 deletions
diff --git a/drivers/staging/android/sync_debug.c b/drivers/staging/android/sync_debug.c index 9032969..4c5a855 100644 --- a/drivers/staging/android/sync_debug.c +++ b/drivers/staging/android/sync_debug.c @@ -189,10 +189,15 @@ static __init int sync_debugfs_init(void) { dbgfs = debugfs_create_dir("sync", NULL); - debugfs_create_file("info", 0444, dbgfs, NULL, &sync_info_debugfs_fops); - - debugfs_create_file("sw_sync", 0644, dbgfs, NULL, - &sw_sync_debugfs_fops); + /* + * The debugfs files won't ever get removed and thus, there is + * no need to protect it against removal races. The use of + * debugfs_create_file_unsafe() is actually safe here. + */ + debugfs_create_file_unsafe("info", 0444, dbgfs, NULL, + &sync_info_debugfs_fops); + debugfs_create_file_unsafe("sw_sync", 0644, dbgfs, NULL, + &sw_sync_debugfs_fops); return 0; } |