[PATCH v2 3/4] binder: Make transaction_log available in binderfs

From: Hridya Valsaraju
Date: Thu Aug 29 2019 - 17:18:49 EST


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@xxxxxxxxxx>
---

Changes in v2:
-Consistent variable naming accross functions as per Christian Brauner.

drivers/android/binder.c | 34 +++++--------------------------
drivers/android/binder_internal.h | 30 +++++++++++++++++++++++++++
drivers/android/binderfs.c | 18 ++++++++++++++++
3 files changed, 53 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 0e1e7c87cd33..1715e72ce9c7 100644
--- 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);

--
2.23.0.187.g17f5b7556c-goog