[PATCH 3/4] binder: Make transaction_log available in binderfs

[Christian Brauner]

On Tue, Aug 27, 2019 at 01:41:51PM -0700, Hridya Valsaraju wrote:
> 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.
> 
> Signed-off-by: Hridya Valsaraju <hridya at google.com>

Acked-by: Christian Brauner <christian.brauner at ubuntu.com>

> ---
>  drivers/android/binder.c          | 34 +++++--------------------------
>  drivers/android/binder_internal.h | 30 +++++++++++++++++++++++++++
>  drivers/android/binderfs.c        | 19 +++++++++++++++++
>  3 files changed, 54 insertions(+), 29 deletions(-)
> 
> diff --git a/drivers/android/binder.c b/drivers/android/binder.c
> index de795bd229c4..bed217310197 100644
> --- a/drivers/android/binder.c
> +++ b/drivers/android/binder.c
> @@ -197,30 +197,8 @@ 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)
> @@ -6166,7 +6144,7 @@ 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);
> @@ -6198,8 +6176,6 @@ 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;
> @@ -6268,12 +6244,12 @@ 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 12ef96f256c6..b9be42d9464c 100644
> --- 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 d542f9b8d8ab..dc25a7d759c9 100644
> --- a/drivers/android/binderfs.c
> +++ b/drivers/android/binderfs.c
> @@ -630,8 +630,27 @@ static int init_binder_logs(struct super_block *sb)
>  
>  	file_dentry = binderfs_create_file(binder_logs_root_dir, "transactions",
>  					   &binder_transactions_fops, NULL);
> +	if (IS_ERR(file_dentry)) {
> +		ret = PTR_ERR(file_dentry);
> +		goto out;
> +	}
> +
> +	file_dentry = binderfs_create_file(binder_logs_root_dir,
> +					   "transaction_log",
> +					   &binder_transaction_log_fops,
> +					   &binder_transaction_log);
> +	if (IS_ERR(file_dentry)) {
> +		ret = PTR_ERR(file_dentry);
> +		goto out;
> +	}
> +
> +	file_dentry = binderfs_create_file(binder_logs_root_dir,
> +					   "failed_transaction_log",
> +					   &binder_transaction_log_fops,
> +					   &binder_transaction_log_failed);
>  	if (IS_ERR(file_dentry))
>  		ret = PTR_ERR(file_dentry);
> +
>  out:
>  	return ret;
>  }
> -- 
> 2.23.0.187.g17f5b7556c-goog
>