binder: fix redefinition of seq_file attributes

The patchset in [1] exported some definitions to binder_internal.h in
order to make the debugfs entries such as 'stats' and 'transaction_log'
available in a binderfs instance. However, the DEFINE_SHOW_ATTRIBUTE
macro expands into a static function/variable pair, which in turn get
redefined each time a source file includes this internal header.

This problem was made evident after a report from the kernel test robot
<lkp@intel.com> where several W=1 build warnings are seen in downstream
kernels. See the following example:

  include/../drivers/android/binder_internal.h:111:23: warning: 'binder_stats_fops' defined but not used [-Wunused-const-variable=]
     111 | DEFINE_SHOW_ATTRIBUTE(binder_stats);
         |                       ^~~~~~~~~~~~
  include/linux/seq_file.h:174:37: note: in definition of macro 'DEFINE_SHOW_ATTRIBUTE'
     174 | static const struct file_operations __name ## _fops = {                 \
         |                                     ^~~~~~

This patch fixes the above issues by moving back the definitions into
binder.c and instead creates an array of the debugfs entries which is
more convenient to share with binderfs and iterate through.

  [1] https://lore.kernel.org/all/20190903161655.107408-1-hridya@google.com/

Fixes: 0e13e452dafc ("binder: Add stats, state and transactions files")
Fixes: 03e2e07e3814 ("binder: Make transaction_log available in binderfs")
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Carlos Llamas <cmllamas@google.com>
Link: https://lore.kernel.org/r/20220701182041.2134313-1-cmllamas@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 10 insertions, 37 deletions

diff --git a/drivers/android/binderfs.c b/drivers/android/binderfs.c
index 6c5e94f6cb3a..588d753a7a19 100644
--- a/drivers/android/binderfs.c
+++ b/drivers/android/binderfs.c
@@ -629,6 +629,7 @@ static int init_binder_features(struct super_block *sb)
 static int init_binder_logs(struct super_block *sb)
 {
 	struct dentry *binder_logs_root_dir, *dentry, *proc_log_dir;
+	const struct binder_debugfs_entry *db_entry;
 	struct binderfs_info *info;
 	int ret = 0;
 
@@ -639,43 +640,15 @@ static int init_binder_logs(struct super_block *sb)
 		goto out;
 	}
 
-	dentry = binderfs_create_file(binder_logs_root_dir, "stats",
-				      &binder_stats_fops, NULL);
-	if (IS_ERR(dentry)) {
-		ret = PTR_ERR(dentry);
-		goto out;
-	}
-
-	dentry = binderfs_create_file(binder_logs_root_dir, "state",
-				      &binder_state_fops, NULL);
-	if (IS_ERR(dentry)) {
-		ret = PTR_ERR(dentry);
-		goto out;
-	}
-
-	dentry = binderfs_create_file(binder_logs_root_dir, "transactions",
-				      &binder_transactions_fops, NULL);
-	if (IS_ERR(dentry)) {
-		ret = PTR_ERR(dentry);
-		goto out;
-	}
-
-	dentry = binderfs_create_file(binder_logs_root_dir,
-				      "transaction_log",
-				      &binder_transaction_log_fops,
-				      &binder_transaction_log);
-	if (IS_ERR(dentry)) {
-		ret = PTR_ERR(dentry);
-		goto out;
-	}
-
-	dentry = binderfs_create_file(binder_logs_root_dir,
-				      "failed_transaction_log",
-				      &binder_transaction_log_fops,
-				      &binder_transaction_log_failed);
-	if (IS_ERR(dentry)) {
-		ret = PTR_ERR(dentry);
-		goto out;
+	binder_for_each_debugfs_entry(db_entry) {
+		dentry = binderfs_create_file(binder_logs_root_dir,
+					      db_entry->name,
+					      db_entry->fops,
+					      db_entry->data);
+		if (IS_ERR(dentry)) {
+			ret = PTR_ERR(dentry);
+			goto out;
+		}
 	}
 
 	proc_log_dir = binderfs_create_dir(binder_logs_root_dir, "proc");