binder: Add binder_proc logging to binderfs

Currently /sys/kernel/debug/binder/proc contains
the debug data for every binder_proc instance.
This patch makes this information also available
in a binderfs instance mounted with a mount option
"stats=global" in addition to debugfs. The patch does
not affect the presence of the file in debugfs.

If a binderfs instance is mounted at path /dev/binderfs,
this file would be present at /dev/binderfs/binder_logs/proc.
This change provides an alternate way to access this file 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/20190903161655.107408-5-hridya@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Hridya Valsaraju 2019-09-03 09:16:55 -07:00 committed by Greg Kroah-Hartman
parent 03e2e07e38
commit 4feb80faf4
3 changed files with 121 additions and 39 deletions

View File

@ -458,6 +458,7 @@ enum binder_deferred_state {
* @inner_lock: can nest under outer_lock and/or node lock
* @outer_lock: no nesting under innor or node lock
* Lock order: 1) outer, 2) node, 3) inner
* @binderfs_entry: process-specific binderfs log file
*
* Bookkeeping structure for binder processes
*/
@ -487,6 +488,7 @@ struct binder_proc {
struct binder_context *context;
spinlock_t inner_lock;
spinlock_t outer_lock;
struct dentry *binderfs_entry;
};
enum {
@ -5208,6 +5210,8 @@ static int binder_open(struct inode *nodp, struct file *filp)
{
struct binder_proc *proc;
struct binder_device *binder_dev;
struct binderfs_info *info;
struct dentry *binder_binderfs_dir_entry_proc = NULL;
binder_debug(BINDER_DEBUG_OPEN_CLOSE, "%s: %d:%d\n", __func__,
current->group_leader->pid, current->pid);
@ -5222,11 +5226,14 @@ static int binder_open(struct inode *nodp, struct file *filp)
INIT_LIST_HEAD(&proc->todo);
proc->default_priority = task_nice(current);
/* binderfs stashes devices in i_private */
if (is_binderfs_device(nodp))
if (is_binderfs_device(nodp)) {
binder_dev = nodp->i_private;
else
info = nodp->i_sb->s_fs_info;
binder_binderfs_dir_entry_proc = info->proc_log_dir;
} else {
binder_dev = container_of(filp->private_data,
struct binder_device, miscdev);
}
proc->context = &binder_dev->context;
binder_alloc_init(&proc->alloc);
@ -5257,6 +5264,35 @@ static int binder_open(struct inode *nodp, struct file *filp)
&proc_fops);
}
if (binder_binderfs_dir_entry_proc) {
char strbuf[11];
struct dentry *binderfs_entry;
snprintf(strbuf, sizeof(strbuf), "%u", proc->pid);
/*
* Similar to debugfs, the process specific log file is shared
* between contexts. If the file has already been created for a
* process, the following binderfs_create_file() call will
* fail with error code EEXIST if another context of the same
* process invoked binder_open(). This is ok since same as
* debugfs, the log file will contain information on all
* contexts of a given PID.
*/
binderfs_entry = binderfs_create_file(binder_binderfs_dir_entry_proc,
strbuf, &proc_fops, (void *)(unsigned long)proc->pid);
if (!IS_ERR(binderfs_entry)) {
proc->binderfs_entry = binderfs_entry;
} else {
int error;
error = PTR_ERR(binderfs_entry);
if (error != -EEXIST) {
pr_warn("Unable to create file %s in binderfs (error %d)\n",
strbuf, error);
}
}
}
return 0;
}
@ -5296,6 +5332,12 @@ static int binder_release(struct inode *nodp, struct file *filp)
struct binder_proc *proc = filp->private_data;
debugfs_remove(proc->debugfs_entry);
if (proc->binderfs_entry) {
binderfs_remove_file(proc->binderfs_entry);
proc->binderfs_entry = NULL;
}
binder_defer_work(proc, BINDER_DEFERRED_RELEASE);
return 0;

View File

@ -35,17 +35,63 @@ struct binder_device {
struct inode *binderfs_inode;
};
/**
* binderfs_mount_opts - mount options for binderfs
* @max: maximum number of allocatable binderfs binder devices
* @stats_mode: enable binder stats in binderfs.
*/
struct binderfs_mount_opts {
int max;
int stats_mode;
};
/**
* binderfs_info - information about a binderfs mount
* @ipc_ns: The ipc namespace the binderfs mount belongs to.
* @control_dentry: This records the dentry of this binderfs mount
* binder-control device.
* @root_uid: uid that needs to be used when a new binder device is
* created.
* @root_gid: gid that needs to be used when a new binder device is
* created.
* @mount_opts: The mount options in use.
* @device_count: The current number of allocated binder devices.
* @proc_log_dir: Pointer to the directory dentry containing process-specific
* logs.
*/
struct binderfs_info {
struct ipc_namespace *ipc_ns;
struct dentry *control_dentry;
kuid_t root_uid;
kgid_t root_gid;
struct binderfs_mount_opts mount_opts;
int device_count;
struct dentry *proc_log_dir;
};
extern const struct file_operations binder_fops;
extern char *binder_devices_param;
#ifdef CONFIG_ANDROID_BINDERFS
extern bool is_binderfs_device(const struct inode *inode);
extern struct dentry *binderfs_create_file(struct dentry *dir, const char *name,
const struct file_operations *fops,
void *data);
extern void binderfs_remove_file(struct dentry *dentry);
#else
static inline bool is_binderfs_device(const struct inode *inode)
{
return false;
}
static inline struct dentry *binderfs_create_file(struct dentry *dir,
const char *name,
const struct file_operations *fops,
void *data)
{
return NULL;
}
static inline void binderfs_remove_file(struct dentry *dentry) {}
#endif
#ifdef CONFIG_ANDROID_BINDERFS

View File

@ -48,16 +48,6 @@ static dev_t binderfs_dev;
static DEFINE_MUTEX(binderfs_minors_mutex);
static DEFINE_IDA(binderfs_minors);
/**
* binderfs_mount_opts - mount options for binderfs
* @max: maximum number of allocatable binderfs binder devices
* @stats_mode: enable binder stats in binderfs.
*/
struct binderfs_mount_opts {
int max;
int stats_mode;
};
enum {
Opt_max,
Opt_stats_mode,
@ -75,27 +65,6 @@ static const match_table_t tokens = {
{ Opt_err, NULL }
};
/**
* binderfs_info - information about a binderfs mount
* @ipc_ns: The ipc namespace the binderfs mount belongs to.
* @control_dentry: This records the dentry of this binderfs mount
* binder-control device.
* @root_uid: uid that needs to be used when a new binder device is
* created.
* @root_gid: gid that needs to be used when a new binder device is
* created.
* @mount_opts: The mount options in use.
* @device_count: The current number of allocated binder devices.
*/
struct binderfs_info {
struct ipc_namespace *ipc_ns;
struct dentry *control_dentry;
kuid_t root_uid;
kgid_t root_gid;
struct binderfs_mount_opts mount_opts;
int device_count;
};
static inline struct binderfs_info *BINDERFS_I(const struct inode *inode)
{
return inode->i_sb->s_fs_info;
@ -533,10 +502,24 @@ static struct dentry *binderfs_create_dentry(struct dentry *parent,
return dentry;
}
static struct dentry *binderfs_create_file(struct dentry *parent,
const char *name,
const struct file_operations *fops,
void *data)
void binderfs_remove_file(struct dentry *dentry)
{
struct inode *parent_inode;
parent_inode = d_inode(dentry->d_parent);
inode_lock(parent_inode);
if (simple_positive(dentry)) {
dget(dentry);
simple_unlink(parent_inode, dentry);
d_delete(dentry);
dput(dentry);
}
inode_unlock(parent_inode);
}
struct dentry *binderfs_create_file(struct dentry *parent, const char *name,
const struct file_operations *fops,
void *data)
{
struct dentry *dentry;
struct inode *new_inode, *parent_inode;
@ -604,7 +587,8 @@ out:
static int init_binder_logs(struct super_block *sb)
{
struct dentry *binder_logs_root_dir, *dentry;
struct dentry *binder_logs_root_dir, *dentry, *proc_log_dir;
struct binderfs_info *info;
int ret = 0;
binder_logs_root_dir = binderfs_create_dir(sb->s_root,
@ -648,8 +632,18 @@ static int init_binder_logs(struct super_block *sb)
"failed_transaction_log",
&binder_transaction_log_fops,
&binder_transaction_log_failed);
if (IS_ERR(dentry))
if (IS_ERR(dentry)) {
ret = PTR_ERR(dentry);
goto out;
}
proc_log_dir = binderfs_create_dir(binder_logs_root_dir, "proc");
if (IS_ERR(proc_log_dir)) {
ret = PTR_ERR(proc_log_dir);
goto out;
}
info = sb->s_fs_info;
info->proc_log_dir = proc_log_dir;
out:
return ret;