From: Nicolai Stange Date: Fri, 27 May 2016 18:03:54 +0000 (+0200) Subject: staging/android: sync_debug: unproxify debugfs files' fops X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=0fd9da9a979aecfb9df40dfb3304db2b16fa7e05;p=linux-beck.git 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 Signed-off-by: Greg Kroah-Hartman --- diff --git a/drivers/staging/android/sync_debug.c b/drivers/staging/android/sync_debug.c index 903296988d41..4c5a85595a85 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; }