binder: Make transaction_log available in binderfs

Currently, the binder transaction log files 'transaction_log'
and 'failed_transaction_log' live in debugfs at the following locations:

/sys/kernel/debug/binder/failed_transaction_log
/sys/kernel/debug/binder/transaction_log

This patch makes these files also available in a binderfs instance
mounted with the mount option "stats=global".
It does not affect the presence of these files in debugfs.
If a binderfs instance is mounted at path /dev/binderfs, the location of
these files will be as follows:

/dev/binderfs/binder_logs/failed_transaction_log
/dev/binderfs/binder_logs/transaction_log

This change provides an alternate option to access these files when
debugfs is not mounted.

Acked-by: Christian Brauner <christian.brauner@ubuntu.com>
Signed-off-by: Hridya Valsaraju <hridya@google.com>
Link: https://lore.kernel.org/r/20190903161655.107408-4-hridya@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/android/binder.c b/drivers/android/binder.c
index 4b4ab579067841a88c15379c88a2a3e8e4bf082f..fe44236de2bd35fae9d4258b9c540005dec82d49 100644 (file)
--- a/drivers/android/binder.c
+++ b/drivers/android/binder.c
@@ -196,30 +196,8 @@ static inline void binder_stats_created(enum binder_stat_types type)
        atomic_inc(&binder_stats.obj_created[type]);
 }
 
-struct binder_transaction_log_entry {
-       int debug_id;
-       int debug_id_done;
-       int call_type;
-       int from_proc;
-       int from_thread;
-       int target_handle;
-       int to_proc;
-       int to_thread;
-       int to_node;
-       int data_size;
-       int offsets_size;
-       int return_error_line;
-       uint32_t return_error;
-       uint32_t return_error_param;
-       const char *context_name;
-};
-struct binder_transaction_log {
-       atomic_t cur;
-       bool full;
-       struct binder_transaction_log_entry entry[32];
-};
-static struct binder_transaction_log binder_transaction_log;
-static struct binder_transaction_log binder_transaction_log_failed;
+struct binder_transaction_log binder_transaction_log;
+struct binder_transaction_log binder_transaction_log_failed;
 
 static struct binder_transaction_log_entry *binder_transaction_log_add(
        struct binder_transaction_log *log)
@@ -6018,7 +5996,7 @@ static void print_binder_transaction_log_entry(struct seq_file *m,
                        "\n" : " (incomplete)\n");
 }
 
-static int transaction_log_show(struct seq_file *m, void *unused)
+int binder_transaction_log_show(struct seq_file *m, void *unused)
 {
        struct binder_transaction_log *log = m->private;
        unsigned int log_cur = atomic_read(&log->cur);
@@ -6050,8 +6028,6 @@ const struct file_operations binder_fops = {
        .release = binder_release,
 };
 
-DEFINE_SHOW_ATTRIBUTE(transaction_log);
-
 static int __init init_binder_device(const char *name)
 {
        int ret;
@@ -6120,12 +6096,12 @@ static int __init binder_init(void)
                                    0444,
                                    binder_debugfs_dir_entry_root,
                                    &binder_transaction_log,
-                                   &transaction_log_fops);
+                                   &binder_transaction_log_fops);
                debugfs_create_file("failed_transaction_log",
                                    0444,
                                    binder_debugfs_dir_entry_root,
                                    &binder_transaction_log_failed,
-                                   &transaction_log_fops);
+                                   &binder_transaction_log_fops);
        }
 
        if (!IS_ENABLED(CONFIG_ANDROID_BINDERFS) &&

diff --git a/drivers/android/binder_internal.h b/drivers/android/binder_internal.h
index 12ef96f256c68e30763e53754f5305b47d2f6e6c..b9be42d9464c897aa3895d75baa0e0379000693b 100644 (file)
--- a/drivers/android/binder_internal.h
+++ b/drivers/android/binder_internal.h
@@ -65,4 +65,34 @@ DEFINE_SHOW_ATTRIBUTE(binder_state);
 
 int binder_transactions_show(struct seq_file *m, void *unused);
 DEFINE_SHOW_ATTRIBUTE(binder_transactions);
+
+int binder_transaction_log_show(struct seq_file *m, void *unused);
+DEFINE_SHOW_ATTRIBUTE(binder_transaction_log);
+
+struct binder_transaction_log_entry {
+       int debug_id;
+       int debug_id_done;
+       int call_type;
+       int from_proc;
+       int from_thread;
+       int target_handle;
+       int to_proc;
+       int to_thread;
+       int to_node;
+       int data_size;
+       int offsets_size;
+       int return_error_line;
+       uint32_t return_error;
+       uint32_t return_error_param;
+       const char *context_name;
+};
+
+struct binder_transaction_log {
+       atomic_t cur;
+       bool full;
+       struct binder_transaction_log_entry entry[32];
+};
+
+extern struct binder_transaction_log binder_transaction_log;
+extern struct binder_transaction_log binder_transaction_log_failed;
 #endif /* _LINUX_BINDER_INTERNAL_H */

diff --git a/drivers/android/binderfs.c b/drivers/android/binderfs.c
index f2539b6a4968e59839fd29b9265358083f71086c..dd5b9f754c7df05a501380cabd37b15b32593fe0 100644 (file)
--- a/drivers/android/binderfs.c
+++ b/drivers/android/binderfs.c
@@ -630,6 +630,24 @@ static int init_binder_logs(struct super_block *sb)
 
        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);