blob: ab34239a76ee53fbb3dc62b0f37b30eaf3a9031e [file] [log] [blame]
/* binder.c
*
* Android IPC Subsystem
*
* Copyright (C) 2007-2008 Google, Inc.
*
* This software is licensed under the terms of the GNU General Public
* License version 2, as published by the Free Software Foundation, and
* may be copied, distributed, and modified under those terms.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
*/
/*
* Locking overview
*
* There are 3 main spinlocks which must be acquired in the
* order shown:
*
* 1) proc->outer_lock : protects binder_ref
* binder_proc_lock() and binder_proc_unlock() are
* used to acq/rel.
* 2) node->lock : protects most fields of binder_node.
* binder_node_lock() and binder_node_unlock() are
* used to acq/rel
* 3) proc->inner_lock : protects the thread and node lists
* (proc->threads, proc->waiting_threads, proc->nodes)
* and all todo lists associated with the binder_proc
* (proc->todo, thread->todo, proc->delivered_death and
* node->async_todo), as well as thread->transaction_stack
* binder_inner_proc_lock() and binder_inner_proc_unlock()
* are used to acq/rel
*
* Any lock under procA must never be nested under any lock at the same
* level or below on procB.
*
* Functions that require a lock held on entry indicate which lock
* in the suffix of the function name:
*
* foo_olocked() : requires node->outer_lock
* foo_nlocked() : requires node->lock
* foo_ilocked() : requires proc->inner_lock
* foo_oilocked(): requires proc->outer_lock and proc->inner_lock
* foo_nilocked(): requires node->lock and proc->inner_lock
* ...
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <asm/cacheflush.h>
#include <linux/fdtable.h>
#include <linux/file.h>
#include <linux/freezer.h>
#include <linux/fs.h>
#include <linux/list.h>
#include <linux/miscdevice.h>
#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/nsproxy.h>
#include <linux/poll.h>
#include <linux/debugfs.h>
#include <linux/rbtree.h>
#include <linux/sched/signal.h>
#include <linux/sched/mm.h>
#include <linux/seq_file.h>
#include <linux/uaccess.h>
#include <linux/pid_namespace.h>
#include <linux/security.h>
#include <linux/spinlock.h>
#ifdef CONFIG_ANDROID_BINDER_IPC_32BIT
#define BINDER_IPC_32BIT 1
#endif
#include <uapi/linux/android/binder.h>
#include "binder_alloc.h"
#include "binder_trace.h"
static HLIST_HEAD(binder_deferred_list);
static DEFINE_MUTEX(binder_deferred_lock);
static HLIST_HEAD(binder_devices);
static HLIST_HEAD(binder_procs);
static DEFINE_MUTEX(binder_procs_lock);
static HLIST_HEAD(binder_dead_nodes);
static DEFINE_SPINLOCK(binder_dead_nodes_lock);
static struct dentry *binder_debugfs_dir_entry_root;
static struct dentry *binder_debugfs_dir_entry_proc;
static atomic_t binder_last_id;
#define BINDER_DEBUG_ENTRY(name) \
static int binder_##name##_open(struct inode *inode, struct file *file) \
{ \
return single_open(file, binder_##name##_show, inode->i_private); \
} \
\
static const struct file_operations binder_##name##_fops = { \
.owner = THIS_MODULE, \
.open = binder_##name##_open, \
.read = seq_read, \
.llseek = seq_lseek, \
.release = single_release, \
}
static int binder_proc_show(struct seq_file *m, void *unused);
BINDER_DEBUG_ENTRY(proc);
/* This is only defined in include/asm-arm/sizes.h */
#ifndef SZ_1K
#define SZ_1K 0x400
#endif
#ifndef SZ_4M
#define SZ_4M 0x400000
#endif
#define FORBIDDEN_MMAP_FLAGS (VM_WRITE)
enum {
BINDER_DEBUG_USER_ERROR = 1U << 0,
BINDER_DEBUG_FAILED_TRANSACTION = 1U << 1,
BINDER_DEBUG_DEAD_TRANSACTION = 1U << 2,
BINDER_DEBUG_OPEN_CLOSE = 1U << 3,
BINDER_DEBUG_DEAD_BINDER = 1U << 4,
BINDER_DEBUG_DEATH_NOTIFICATION = 1U << 5,
BINDER_DEBUG_READ_WRITE = 1U << 6,
BINDER_DEBUG_USER_REFS = 1U << 7,
BINDER_DEBUG_THREADS = 1U << 8,
BINDER_DEBUG_TRANSACTION = 1U << 9,
BINDER_DEBUG_TRANSACTION_COMPLETE = 1U << 10,
BINDER_DEBUG_FREE_BUFFER = 1U << 11,
BINDER_DEBUG_INTERNAL_REFS = 1U << 12,
BINDER_DEBUG_PRIORITY_CAP = 1U << 13,
BINDER_DEBUG_SPINLOCKS = 1U << 14,
};
static uint32_t binder_debug_mask = BINDER_DEBUG_USER_ERROR |
BINDER_DEBUG_FAILED_TRANSACTION | BINDER_DEBUG_DEAD_TRANSACTION;
module_param_named(debug_mask, binder_debug_mask, uint, S_IWUSR | S_IRUGO);
static char *binder_devices_param = CONFIG_ANDROID_BINDER_DEVICES;
module_param_named(devices, binder_devices_param, charp, 0444);
static DECLARE_WAIT_QUEUE_HEAD(binder_user_error_wait);
static int binder_stop_on_user_error;
static int binder_set_stop_on_user_error(const char *val,
struct kernel_param *kp)
{
int ret;
ret = param_set_int(val, kp);
if (binder_stop_on_user_error < 2)
wake_up(&binder_user_error_wait);
return ret;
}
module_param_call(stop_on_user_error, binder_set_stop_on_user_error,
param_get_int, &binder_stop_on_user_error, S_IWUSR | S_IRUGO);
#define binder_debug(mask, x...) \
do { \
if (binder_debug_mask & mask) \
pr_info(x); \
} while (0)
#define binder_user_error(x...) \
do { \
if (binder_debug_mask & BINDER_DEBUG_USER_ERROR) \
pr_info(x); \
if (binder_stop_on_user_error) \
binder_stop_on_user_error = 2; \
} while (0)
#define to_flat_binder_object(hdr) \
container_of(hdr, struct flat_binder_object, hdr)
#define to_binder_fd_object(hdr) container_of(hdr, struct binder_fd_object, hdr)
#define to_binder_buffer_object(hdr) \
container_of(hdr, struct binder_buffer_object, hdr)
#define to_binder_fd_array_object(hdr) \
container_of(hdr, struct binder_fd_array_object, hdr)
enum binder_stat_types {
BINDER_STAT_PROC,
BINDER_STAT_THREAD,
BINDER_STAT_NODE,
BINDER_STAT_REF,
BINDER_STAT_DEATH,
BINDER_STAT_TRANSACTION,
BINDER_STAT_TRANSACTION_COMPLETE,
BINDER_STAT_COUNT
};
struct binder_stats {
atomic_t br[_IOC_NR(BR_FAILED_REPLY) + 1];
atomic_t bc[_IOC_NR(BC_REPLY_SG) + 1];
atomic_t obj_created[BINDER_STAT_COUNT];
atomic_t obj_deleted[BINDER_STAT_COUNT];
};
static struct binder_stats binder_stats;
static inline void binder_stats_deleted(enum binder_stat_types type)
{
atomic_inc(&binder_stats.obj_deleted[type]);
}
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;
static struct binder_transaction_log_entry *binder_transaction_log_add(
struct binder_transaction_log *log)
{
struct binder_transaction_log_entry *e;
unsigned int cur = atomic_inc_return(&log->cur);
if (cur >= ARRAY_SIZE(log->entry))
log->full = 1;
e = &log->entry[cur % ARRAY_SIZE(log->entry)];
WRITE_ONCE(e->debug_id_done, 0);
/*
* write-barrier to synchronize access to e->debug_id_done.
* We make sure the initialized 0 value is seen before
* memset() other fields are zeroed by memset.
*/
smp_wmb();
memset(e, 0, sizeof(*e));
return e;
}
struct binder_context {
struct binder_node *binder_context_mgr_node;
struct mutex context_mgr_node_lock;
kuid_t binder_context_mgr_uid;
const char *name;
};
struct binder_device {
struct hlist_node hlist;
struct miscdevice miscdev;
struct binder_context context;
};
/**
* struct binder_work - work enqueued on a worklist
* @entry: node enqueued on list
* @type: type of work to be performed
*
* There are separate work lists for proc, thread, and node (async).
*/
struct binder_work {
struct list_head entry;
enum {
BINDER_WORK_TRANSACTION = 1,
BINDER_WORK_TRANSACTION_COMPLETE,
BINDER_WORK_RETURN_ERROR,
BINDER_WORK_NODE,
BINDER_WORK_DEAD_BINDER,
BINDER_WORK_DEAD_BINDER_AND_CLEAR,
BINDER_WORK_CLEAR_DEATH_NOTIFICATION,
} type;
};
struct binder_error {
struct binder_work work;
uint32_t cmd;
};
/**
* struct binder_node - binder node bookkeeping
* @debug_id: unique ID for debugging
* (invariant after initialized)
* @lock: lock for node fields
* @work: worklist element for node work
* (protected by @proc->inner_lock)
* @rb_node: element for proc->nodes tree
* (protected by @proc->inner_lock)
* @dead_node: element for binder_dead_nodes list
* (protected by binder_dead_nodes_lock)
* @proc: binder_proc that owns this node
* (invariant after initialized)
* @refs: list of references on this node
* (protected by @lock)
* @internal_strong_refs: used to take strong references when
* initiating a transaction
* (protected by @proc->inner_lock if @proc
* and by @lock)
* @local_weak_refs: weak user refs from local process
* (protected by @proc->inner_lock if @proc
* and by @lock)
* @local_strong_refs: strong user refs from local process
* (protected by @proc->inner_lock if @proc
* and by @lock)
* @tmp_refs: temporary kernel refs
* (protected by @proc->inner_lock while @proc
* is valid, and by binder_dead_nodes_lock
* if @proc is NULL. During inc/dec and node release
* it is also protected by @lock to provide safety
* as the node dies and @proc becomes NULL)
* @ptr: userspace pointer for node
* (invariant, no lock needed)
* @cookie: userspace cookie for node
* (invariant, no lock needed)
* @has_strong_ref: userspace notified of strong ref
* (protected by @proc->inner_lock if @proc
* and by @lock)
* @pending_strong_ref: userspace has acked notification of strong ref
* (protected by @proc->inner_lock if @proc
* and by @lock)
* @has_weak_ref: userspace notified of weak ref
* (protected by @proc->inner_lock if @proc
* and by @lock)
* @pending_weak_ref: userspace has acked notification of weak ref
* (protected by @proc->inner_lock if @proc
* and by @lock)
* @has_async_transaction: async transaction to node in progress
* (protected by @lock)
* @accept_fds: file descriptor operations supported for node
* (invariant after initialized)
* @min_priority: minimum scheduling priority
* (invariant after initialized)
* @async_todo: list of async work items
* (protected by @proc->inner_lock)
*
* Bookkeeping structure for binder nodes.
*/
struct binder_node {
int debug_id;
spinlock_t lock;
struct binder_work work;
union {
struct rb_node rb_node;
struct hlist_node dead_node;
};
struct binder_proc *proc;
struct hlist_head refs;
int internal_strong_refs;
int local_weak_refs;
int local_strong_refs;
int tmp_refs;
binder_uintptr_t ptr;
binder_uintptr_t cookie;
struct {
/*
* bitfield elements protected by
* proc inner_lock
*/
u8 has_strong_ref:1;
u8 pending_strong_ref:1;
u8 has_weak_ref:1;
u8 pending_weak_ref:1;
};
struct {
/*
* invariant after initialization
*/
u8 accept_fds:1;
u8 min_priority;
};
bool has_async_transaction;
struct list_head async_todo;
};
struct binder_ref_death {
/**
* @work: worklist element for death notifications
* (protected by inner_lock of the proc that
* this ref belongs to)
*/
struct binder_work work;
binder_uintptr_t cookie;
};
/**
* struct binder_ref_data - binder_ref counts and id
* @debug_id: unique ID for the ref
* @desc: unique userspace handle for ref
* @strong: strong ref count (debugging only if not locked)
* @weak: weak ref count (debugging only if not locked)
*
* Structure to hold ref count and ref id information. Since
* the actual ref can only be accessed with a lock, this structure
* is used to return information about the ref to callers of
* ref inc/dec functions.
*/
struct binder_ref_data {
int debug_id;
uint32_t desc;
int strong;
int weak;
};
/**
* struct binder_ref - struct to track references on nodes
* @data: binder_ref_data containing id, handle, and current refcounts
* @rb_node_desc: node for lookup by @data.desc in proc's rb_tree
* @rb_node_node: node for lookup by @node in proc's rb_tree
* @node_entry: list entry for node->refs list in target node
* (protected by @node->lock)
* @proc: binder_proc containing ref
* @node: binder_node of target node. When cleaning up a
* ref for deletion in binder_cleanup_ref, a non-NULL
* @node indicates the node must be freed
* @death: pointer to death notification (ref_death) if requested
* (protected by @node->lock)
*
* Structure to track references from procA to target node (on procB). This
* structure is unsafe to access without holding @proc->outer_lock.
*/
struct binder_ref {
/* Lookups needed: */
/* node + proc => ref (transaction) */
/* desc + proc => ref (transaction, inc/dec ref) */
/* node => refs + procs (proc exit) */
struct binder_ref_data data;
struct rb_node rb_node_desc;
struct rb_node rb_node_node;
struct hlist_node node_entry;
struct binder_proc *proc;
struct binder_node *node;
struct binder_ref_death *death;
};
enum binder_deferred_state {
BINDER_DEFERRED_PUT_FILES = 0x01,
BINDER_DEFERRED_FLUSH = 0x02,
BINDER_DEFERRED_RELEASE = 0x04,
};
/**
* struct binder_proc - binder process bookkeeping
* @proc_node: element for binder_procs list
* @threads: rbtree of binder_threads in this proc
* (protected by @inner_lock)
* @nodes: rbtree of binder nodes associated with
* this proc ordered by node->ptr
* (protected by @inner_lock)
* @refs_by_desc: rbtree of refs ordered by ref->desc
* (protected by @outer_lock)
* @refs_by_node: rbtree of refs ordered by ref->node
* (protected by @outer_lock)
* @waiting_threads: threads currently waiting for proc work
* (protected by @inner_lock)
* @pid PID of group_leader of process
* (invariant after initialized)
* @tsk task_struct for group_leader of process
* (invariant after initialized)
* @files files_struct for process
* (invariant after initialized)
* @deferred_work_node: element for binder_deferred_list
* (protected by binder_deferred_lock)
* @deferred_work: bitmap of deferred work to perform
* (protected by binder_deferred_lock)
* @is_dead: process is dead and awaiting free
* when outstanding transactions are cleaned up
* (protected by @inner_lock)
* @todo: list of work for this process
* (protected by @inner_lock)
* @wait: wait queue head to wait for proc work
* (invariant after initialized)
* @stats: per-process binder statistics
* (atomics, no lock needed)
* @delivered_death: list of delivered death notification
* (protected by @inner_lock)
* @max_threads: cap on number of binder threads
* (protected by @inner_lock)
* @requested_threads: number of binder threads requested but not
* yet started. In current implementation, can
* only be 0 or 1.
* (protected by @inner_lock)
* @requested_threads_started: number binder threads started
* (protected by @inner_lock)
* @tmp_ref: temporary reference to indicate proc is in use
* (protected by @inner_lock)
* @default_priority: default scheduler priority
* (invariant after initialized)
* @debugfs_entry: debugfs node
* @alloc: binder allocator bookkeeping
* @context: binder_context for this proc
* (invariant after initialized)
* @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
*
* Bookkeeping structure for binder processes
*/
struct binder_proc {
struct hlist_node proc_node;
struct rb_root threads;
struct rb_root nodes;
struct rb_root refs_by_desc;
struct rb_root refs_by_node;
struct list_head waiting_threads;
int pid;
struct task_struct *tsk;
struct files_struct *files;
struct hlist_node deferred_work_node;
int deferred_work;
bool is_dead;
struct list_head todo;
wait_queue_head_t wait;
struct binder_stats stats;
struct list_head delivered_death;
int max_threads;
int requested_threads;
int requested_threads_started;
int tmp_ref;
long default_priority;
struct dentry *debugfs_entry;
struct binder_alloc alloc;
struct binder_context *context;
spinlock_t inner_lock;
spinlock_t outer_lock;
};
enum {
BINDER_LOOPER_STATE_REGISTERED = 0x01,
BINDER_LOOPER_STATE_ENTERED = 0x02,
BINDER_LOOPER_STATE_EXITED = 0x04,
BINDER_LOOPER_STATE_INVALID = 0x08,
BINDER_LOOPER_STATE_WAITING = 0x10,
BINDER_LOOPER_STATE_POLL = 0x20,
};
/**
* struct binder_thread - binder thread bookkeeping
* @proc: binder process for this thread
* (invariant after initialization)
* @rb_node: element for proc->threads rbtree
* (protected by @proc->inner_lock)
* @waiting_thread_node: element for @proc->waiting_threads list
* (protected by @proc->inner_lock)
* @pid: PID for this thread
* (invariant after initialization)
* @looper: bitmap of looping state
* (only accessed by this thread)
* @looper_needs_return: looping thread needs to exit driver
* (no lock needed)
* @transaction_stack: stack of in-progress transactions for this thread
* (protected by @proc->inner_lock)
* @todo: list of work to do for this thread
* (protected by @proc->inner_lock)
* @return_error: transaction errors reported by this thread
* (only accessed by this thread)
* @reply_error: transaction errors reported by target thread
* (protected by @proc->inner_lock)
* @wait: wait queue for thread work
* @stats: per-thread statistics
* (atomics, no lock needed)
* @tmp_ref: temporary reference to indicate thread is in use
* (atomic since @proc->inner_lock cannot
* always be acquired)
* @is_dead: thread is dead and awaiting free
* when outstanding transactions are cleaned up
* (protected by @proc->inner_lock)
*
* Bookkeeping structure for binder threads.
*/
struct binder_thread {
struct binder_proc *proc;
struct rb_node rb_node;
struct list_head waiting_thread_node;
int pid;
int looper; /* only modified by this thread */
bool looper_need_return; /* can be written by other thread */
struct binder_transaction *transaction_stack;
struct list_head todo;
struct binder_error return_error;
struct binder_error reply_error;
wait_queue_head_t wait;
struct binder_stats stats;
atomic_t tmp_ref;
bool is_dead;
};
struct binder_transaction {
int debug_id;
struct binder_work work;
struct binder_thread *from;
struct binder_transaction *from_parent;
struct binder_proc *to_proc;
struct binder_thread *to_thread;
struct binder_transaction *to_parent;
unsigned need_reply:1;
/* unsigned is_dead:1; */ /* not used at the moment */
struct binder_buffer *buffer;
unsigned int code;
unsigned int flags;
long priority;
long saved_priority;
kuid_t sender_euid;
/**
* @lock: protects @from, @to_proc, and @to_thread
*
* @from, @to_proc, and @to_thread can be set to NULL
* during thread teardown
*/
spinlock_t lock;
};
/**
* binder_proc_lock() - Acquire outer lock for given binder_proc
* @proc: struct binder_proc to acquire
*
* Acquires proc->outer_lock. Used to protect binder_ref
* structures associated with the given proc.
*/
#define binder_proc_lock(proc) _binder_proc_lock(proc, __LINE__)
static void
_binder_proc_lock(struct binder_proc *proc, int line)
{
binder_debug(BINDER_DEBUG_SPINLOCKS,
"%s: line=%d\n", __func__, line);
spin_lock(&proc->outer_lock);
}
/**
* binder_proc_unlock() - Release spinlock for given binder_proc
* @proc: struct binder_proc to acquire
*
* Release lock acquired via binder_proc_lock()
*/
#define binder_proc_unlock(_proc) _binder_proc_unlock(_proc, __LINE__)
static void
_binder_proc_unlock(struct binder_proc *proc, int line)
{
binder_debug(BINDER_DEBUG_SPINLOCKS,
"%s: line=%d\n", __func__, line);
spin_unlock(&proc->outer_lock);
}
/**
* binder_inner_proc_lock() - Acquire inner lock for given binder_proc
* @proc: struct binder_proc to acquire
*
* Acquires proc->inner_lock. Used to protect todo lists
*/
#define binder_inner_proc_lock(proc) _binder_inner_proc_lock(proc, __LINE__)
static void
_binder_inner_proc_lock(struct binder_proc *proc, int line)
{
binder_debug(BINDER_DEBUG_SPINLOCKS,
"%s: line=%d\n", __func__, line);
spin_lock(&proc->inner_lock);
}
/**
* binder_inner_proc_unlock() - Release inner lock for given binder_proc
* @proc: struct binder_proc to acquire
*
* Release lock acquired via binder_inner_proc_lock()
*/
#define binder_inner_proc_unlock(proc) _binder_inner_proc_unlock(proc, __LINE__)
static void
_binder_inner_proc_unlock(struct binder_proc *proc, int line)
{
binder_debug(BINDER_DEBUG_SPINLOCKS,
"%s: line=%d\n", __func__, line);
spin_unlock(&proc->inner_lock);
}
/**
* binder_node_lock() - Acquire spinlock for given binder_node
* @node: struct binder_node to acquire
*
* Acquires node->lock. Used to protect binder_node fields
*/
#define binder_node_lock(node) _binder_node_lock(node, __LINE__)
static void
_binder_node_lock(struct binder_node *node, int line)
{
binder_debug(BINDER_DEBUG_SPINLOCKS,
"%s: line=%d\n", __func__, line);
spin_lock(&node->lock);
}
/**
* binder_node_unlock() - Release spinlock for given binder_proc
* @node: struct binder_node to acquire
*
* Release lock acquired via binder_node_lock()
*/
#define binder_node_unlock(node) _binder_node_unlock(node, __LINE__)
static void
_binder_node_unlock(struct binder_node *node, int line)
{
binder_debug(BINDER_DEBUG_SPINLOCKS,
"%s: line=%d\n", __func__, line);
spin_unlock(&node->lock);
}
/**
* binder_node_inner_lock() - Acquire node and inner locks
* @node: struct binder_node to acquire
*
* Acquires node->lock. If node->proc also acquires
* proc->inner_lock. Used to protect binder_node fields
*/
#define binder_node_inner_lock(node) _binder_node_inner_lock(node, __LINE__)
static void
_binder_node_inner_lock(struct binder_node *node, int line)
{
binder_debug(BINDER_DEBUG_SPINLOCKS,
"%s: line=%d\n", __func__, line);
spin_lock(&node->lock);
if (node->proc)
binder_inner_proc_lock(node->proc);
}
/**
* binder_node_unlock() - Release node and inner locks
* @node: struct binder_node to acquire
*
* Release lock acquired via binder_node_lock()
*/
#define binder_node_inner_unlock(node) _binder_node_inner_unlock(node, __LINE__)
static void
_binder_node_inner_unlock(struct binder_node *node, int line)
{
struct binder_proc *proc = node->proc;
binder_debug(BINDER_DEBUG_SPINLOCKS,
"%s: line=%d\n", __func__, line);
if (proc)
binder_inner_proc_unlock(proc);
spin_unlock(&node->lock);
}
static bool binder_worklist_empty_ilocked(struct list_head *list)
{
return list_empty(list);
}
/**
* binder_worklist_empty() - Check if no items on the work list
* @proc: binder_proc associated with list
* @list: list to check
*
* Return: true if there are no items on list, else false
*/
static bool binder_worklist_empty(struct binder_proc *proc,
struct list_head *list)
{
bool ret;
binder_inner_proc_lock(proc);
ret = binder_worklist_empty_ilocked(list);
binder_inner_proc_unlock(proc);
return ret;
}
static void
binder_enqueue_work_ilocked(struct binder_work *work,
struct list_head *target_list)
{
BUG_ON(target_list == NULL);
BUG_ON(work->entry.next && !list_empty(&work->entry));
list_add_tail(&work->entry, target_list);
}
/**
* binder_enqueue_work() - Add an item to the work list
* @proc: binder_proc associated with list
* @work: struct binder_work to add to list
* @target_list: list to add work to
*
* Adds the work to the specified list. Asserts that work
* is not already on a list.
*/
static void
binder_enqueue_work(struct binder_proc *proc,
struct binder_work *work,
struct list_head *target_list)
{
binder_inner_proc_lock(proc);
binder_enqueue_work_ilocked(work, target_list);
binder_inner_proc_unlock(proc);
}
static void
binder_dequeue_work_ilocked(struct binder_work *work)
{
list_del_init(&work->entry);
}
/**
* binder_dequeue_work() - Removes an item from the work list
* @proc: binder_proc associated with list
* @work: struct binder_work to remove from list
*
* Removes the specified work item from whatever list it is on.
* Can safely be called if work is not on any list.
*/
static void
binder_dequeue_work(struct binder_proc *proc, struct binder_work *work)
{
binder_inner_proc_lock(proc);
binder_dequeue_work_ilocked(work);
binder_inner_proc_unlock(proc);
}
static struct binder_work *binder_dequeue_work_head_ilocked(
struct list_head *list)
{
struct binder_work *w;
w = list_first_entry_or_null(list, struct binder_work, entry);
if (w)
list_del_init(&w->entry);
return w;
}
/**
* binder_dequeue_work_head() - Dequeues the item at head of list
* @proc: binder_proc associated with list
* @list: list to dequeue head
*
* Removes the head of the list if there are items on the list
*
* Return: pointer dequeued binder_work, NULL if list was empty
*/
static struct binder_work *binder_dequeue_work_head(
struct binder_proc *proc,
struct list_head *list)
{
struct binder_work *w;
binder_inner_proc_lock(proc);
w = binder_dequeue_work_head_ilocked(list);
binder_inner_proc_unlock(proc);
return w;
}
static void
binder_defer_work(struct binder_proc *proc, enum binder_deferred_state defer);
static void binder_free_thread(struct binder_thread *thread);
static void binder_free_proc(struct binder_proc *proc);
static void binder_inc_node_tmpref_ilocked(struct binder_node *node);
static int task_get_unused_fd_flags(struct binder_proc *proc, int flags)
{
struct files_struct *files = proc->files;
unsigned long rlim_cur;
unsigned long irqs;
if (files == NULL)
return -ESRCH;
if (!lock_task_sighand(proc->tsk, &irqs))
return -EMFILE;
rlim_cur = task_rlimit(proc->tsk, RLIMIT_NOFILE);
unlock_task_sighand(proc->tsk, &irqs);
return __alloc_fd(files, 0, rlim_cur, flags);
}
/*
* copied from fd_install
*/
static void task_fd_install(
struct binder_proc *proc, unsigned int fd, struct file *file)
{
if (proc->files)
__fd_install(proc->files, fd, file);
}
/*
* copied from sys_close
*/
static long task_close_fd(struct binder_proc *proc, unsigned int fd)
{
int retval;
if (proc->files == NULL)
return -ESRCH;
retval = __close_fd(proc->files, fd);
/* can't restart close syscall because file table entry was cleared */
if (unlikely(retval == -ERESTARTSYS ||
retval == -ERESTARTNOINTR ||
retval == -ERESTARTNOHAND ||
retval == -ERESTART_RESTARTBLOCK))
retval = -EINTR;
return retval;
}
static bool binder_has_work_ilocked(struct binder_thread *thread,
bool do_proc_work)
{
return !binder_worklist_empty_ilocked(&thread->todo) ||
thread->looper_need_return ||
(do_proc_work &&
!binder_worklist_empty_ilocked(&thread->proc->todo));
}
static bool binder_has_work(struct binder_thread *thread, bool do_proc_work)
{
bool has_work;
binder_inner_proc_lock(thread->proc);
has_work = binder_has_work_ilocked(thread, do_proc_work);
binder_inner_proc_unlock(thread->proc);
return has_work;
}
static bool binder_available_for_proc_work_ilocked(struct binder_thread *thread)
{
return !thread->transaction_stack &&
binder_worklist_empty_ilocked(&thread->todo) &&
(thread->looper & (BINDER_LOOPER_STATE_ENTERED |
BINDER_LOOPER_STATE_REGISTERED));
}
static void binder_wakeup_poll_threads_ilocked(struct binder_proc *proc,
bool sync)
{
struct rb_node *n;
struct binder_thread *thread;
for (n = rb_first(&proc->threads); n != NULL; n = rb_next(n)) {
thread = rb_entry(n, struct binder_thread, rb_node);
if (thread->looper & BINDER_LOOPER_STATE_POLL &&
binder_available_for_proc_work_ilocked(thread)) {
if (sync)
wake_up_interruptible_sync(&thread->wait);
else
wake_up_interruptible(&thread->wait);
}
}
}
/**
* binder_select_thread_ilocked() - selects a thread for doing proc work.
* @proc: process to select a thread from
*
* Note that calling this function moves the thread off the waiting_threads
* list, so it can only be woken up by the caller of this function, or a
* signal. Therefore, callers *should* always wake up the thread this function
* returns.
*
* Return: If there's a thread currently waiting for process work,
* returns that thread. Otherwise returns NULL.
*/
static struct binder_thread *
binder_select_thread_ilocked(struct binder_proc *proc)
{
struct binder_thread *thread;
assert_spin_locked(&proc->inner_lock);
thread = list_first_entry_or_null(&proc->waiting_threads,
struct binder_thread,
waiting_thread_node);
if (thread)
list_del_init(&thread->waiting_thread_node);
return thread;
}
/**
* binder_wakeup_thread_ilocked() - wakes up a thread for doing proc work.
* @proc: process to wake up a thread in
* @thread: specific thread to wake-up (may be NULL)
* @sync: whether to do a synchronous wake-up
*
* This function wakes up a thread in the @proc process.
* The caller may provide a specific thread to wake-up in
* the @thread parameter. If @thread is NULL, this function
* will wake up threads that have called poll().
*
* Note that for this function to work as expected, callers
* should first call binder_select_thread() to find a thread
* to handle the work (if they don't have a thread already),
* and pass the result into the @thread parameter.
*/
static void binder_wakeup_thread_ilocked(struct binder_proc *proc,
struct binder_thread *thread,
bool sync)
{
assert_spin_locked(&proc->inner_lock);
if (thread) {
if (sync)
wake_up_interruptible_sync(&thread->wait);
else
wake_up_interruptible(&thread->wait);
return;
}
/* Didn't find a thread waiting for proc work; this can happen
* in two scenarios:
* 1. All threads are busy handling transactions
* In that case, one of those threads should call back into
* the kernel driver soon and pick up this work.
* 2. Threads are using the (e)poll interface, in which case
* they may be blocked on the waitqueue without having been
* added to waiting_threads. For this case, we just iterate
* over all threads not handling transaction work, and
* wake them all up. We wake all because we don't know whether
* a thread that called into (e)poll is handling non-binder
* work currently.
*/
binder_wakeup_poll_threads_ilocked(proc, sync);
}
static void binder_wakeup_proc_ilocked(struct binder_proc *proc)
{
struct binder_thread *thread = binder_select_thread_ilocked(proc);
binder_wakeup_thread_ilocked(proc, thread, /* sync = */false);
}
static void binder_set_nice(long nice)
{
long min_nice;
if (can_nice(current, nice)) {
set_user_nice(current, nice);
return;
}
min_nice = rlimit_to_nice(rlimit(RLIMIT_NICE));
binder_debug(BINDER_DEBUG_PRIORITY_CAP,
"%d: nice value %ld not allowed use %ld instead\n",
current->pid, nice, min_nice);
set_user_nice(current, min_nice);
if (min_nice <= MAX_NICE)
return;
binder_user_error("%d RLIMIT_NICE not set\n", current->pid);
}
static struct binder_node *binder_get_node_ilocked(struct binder_proc *proc,
binder_uintptr_t ptr)
{
struct rb_node *n = proc->nodes.rb_node;
struct binder_node *node;
assert_spin_locked(&proc->inner_lock);
while (n) {
node = rb_entry(n, struct binder_node, rb_node);
if (ptr < node->ptr)
n = n->rb_left;
else if (ptr > node->ptr)
n = n->rb_right;
else {
/*
* take an implicit weak reference
* to ensure node stays alive until
* call to binder_put_node()
*/
binder_inc_node_tmpref_ilocked(node);
return node;
}
}
return NULL;
}
static struct binder_node *binder_get_node(struct binder_proc *proc,
binder_uintptr_t ptr)
{
struct binder_node *node;
binder_inner_proc_lock(proc);
node = binder_get_node_ilocked(proc, ptr);
binder_inner_proc_unlock(proc);
return node;
}
static struct binder_node *binder_init_node_ilocked(
struct binder_proc *proc,
struct binder_node *new_node,
struct flat_binder_object *fp)
{
struct rb_node **p = &proc->nodes.rb_node;
struct rb_node *parent = NULL;
struct binder_node *node;
binder_uintptr_t ptr = fp ? fp->binder : 0;
binder_uintptr_t cookie = fp ? fp->cookie : 0;
__u32 flags = fp ? fp->flags : 0;
assert_spin_locked(&proc->inner_lock);
while (*p) {
parent = *p;
node = rb_entry(parent, struct binder_node, rb_node);
if (ptr < node->ptr)
p = &(*p)->rb_left;
else if (ptr > node->ptr)
p = &(*p)->rb_right;
else {
/*
* A matching node is already in
* the rb tree. Abandon the init
* and return it.
*/
binder_inc_node_tmpref_ilocked(node);
return node;
}
}
node = new_node;
binder_stats_created(BINDER_STAT_NODE);
node->tmp_refs++;
rb_link_node(&node->rb_node, parent, p);
rb_insert_color(&node->rb_node, &proc->nodes);
node->debug_id = atomic_inc_return(&binder_last_id);
node->proc = proc;
node->ptr = ptr;
node->cookie = cookie;
node->work.type = BINDER_WORK_NODE;
node->min_priority = flags & FLAT_BINDER_FLAG_PRIORITY_MASK;
node->accept_fds = !!(flags & FLAT_BINDER_FLAG_ACCEPTS_FDS);
spin_lock_init(&node->lock);
INIT_LIST_HEAD(&node->work.entry);
INIT_LIST_HEAD(&node->async_todo);
binder_debug(BINDER_DEBUG_INTERNAL_REFS,
"%d:%d node %d u%016llx c%016llx created\n",
proc->pid, current->pid, node->debug_id,
(u64)node->ptr, (u64)node->cookie);
return node;
}
static struct binder_node *binder_new_node(struct binder_proc *proc,
struct flat_binder_object *fp)
{
struct binder_node *node;
struct binder_node *new_node = kzalloc(sizeof(*node), GFP_KERNEL);
if (!new_node)
return NULL;
binder_inner_proc_lock(proc);
node = binder_init_node_ilocked(proc, new_node, fp);
binder_inner_proc_unlock(proc);
if (node != new_node)
/*
* The node was already added by another thread
*/
kfree(new_node);
return node;
}
static void binder_free_node(struct binder_node *node)
{
kfree(node);
binder_stats_deleted(BINDER_STAT_NODE);
}
static int binder_inc_node_nilocked(struct binder_node *node, int strong,
int internal,
struct list_head *target_list)
{
struct binder_proc *proc = node->proc;
assert_spin_locked(&node->lock);
if (proc)
assert_spin_locked(&proc->inner_lock);
if (strong) {
if (internal) {
if (target_list == NULL &&
node->internal_strong_refs == 0 &&
!(node->proc &&
node == node->proc->context->binder_context_mgr_node &&
node->has_strong_ref)) {
pr_err("invalid inc strong node for %d\n",
node->debug_id);
return -EINVAL;
}
node->internal_strong_refs++;
} else
node->local_strong_refs++;
if (!node->has_strong_ref && target_list) {
binder_dequeue_work_ilocked(&node->work);
binder_enqueue_work_ilocked(&node->work, target_list);
}
} else {
if (!internal)
node->local_weak_refs++;
if (!node->has_weak_ref && list_empty(&node->work.entry)) {
if (target_list == NULL) {
pr_err("invalid inc weak node for %d\n",
node->debug_id);
return -EINVAL;
}
binder_enqueue_work_ilocked(&node->work, target_list);
}
}
return 0;
}
static int binder_inc_node(struct binder_node *node, int strong, int internal,
struct list_head *target_list)
{
int ret;
binder_node_inner_lock(node);
ret = binder_inc_node_nilocked(node, strong, internal, target_list);
binder_node_inner_unlock(node);
return ret;
}
static bool binder_dec_node_nilocked(struct binder_node *node,
int strong, int internal)
{
struct binder_proc *proc = node->proc;
assert_spin_locked(&node->lock);
if (proc)
assert_spin_locked(&proc->inner_lock);
if (strong) {
if (internal)
node->internal_strong_refs--;
else
node->local_strong_refs--;
if (node->local_strong_refs || node->internal_strong_refs)
return false;
} else {
if (!internal)
node->local_weak_refs--;
if (node->local_weak_refs || node->tmp_refs ||
!hlist_empty(&node->refs))
return false;
}
if (proc && (node->has_strong_ref || node->has_weak_ref)) {
if (list_empty(&node->work.entry)) {
binder_enqueue_work_ilocked(&node->work, &proc->todo);
binder_wakeup_proc_ilocked(proc);
}
} else {
if (hlist_empty(&node->refs) && !node->local_strong_refs &&
!node->local_weak_refs && !node->tmp_refs) {
if (proc) {
binder_dequeue_work_ilocked(&node->work);
rb_erase(&node->rb_node, &proc->nodes);
binder_debug(BINDER_DEBUG_INTERNAL_REFS,
"refless node %d deleted\n",
node->debug_id);
} else {
BUG_ON(!list_empty(&node->work.entry));
spin_lock(&binder_dead_nodes_lock);
/*
* tmp_refs could have changed so
* check it again
*/
if (node->tmp_refs) {
spin_unlock(&binder_dead_nodes_lock);
return false;
}
hlist_del(&node->dead_node);
spin_unlock(&binder_dead_nodes_lock);
binder_debug(BINDER_DEBUG_INTERNAL_REFS,
"dead node %d deleted\n",
node->debug_id);
}
return true;
}
}
return false;
}
static void binder_dec_node(struct binder_node *node, int strong, int internal)
{
bool free_node;
binder_node_inner_lock(node);
free_node = binder_dec_node_nilocked(node, strong, internal);
binder_node_inner_unlock(node);
if (free_node)
binder_free_node(node);
}
static void binder_inc_node_tmpref_ilocked(struct binder_node *node)
{
/*
* No call to binder_inc_node() is needed since we
* don't need to inform userspace of any changes to
* tmp_refs
*/
node->tmp_refs++;
}
/**
* binder_inc_node_tmpref() - take a temporary reference on node
* @node: node to reference
*
* Take reference on node to prevent the node from being freed
* while referenced only by a local variable. The inner lock is
* needed to serialize with the node work on the queue (which
* isn't needed after the node is dead). If the node is dead
* (node->proc is NULL), use binder_dead_nodes_lock to protect
* node->tmp_refs against dead-node-only cases where the node
* lock cannot be acquired (eg traversing the dead node list to
* print nodes)
*/
static void binder_inc_node_tmpref(struct binder_node *node)
{
binder_node_lock(node);
if (node->proc)
binder_inner_proc_lock(node->proc);
else
spin_lock(&binder_dead_nodes_lock);
binder_inc_node_tmpref_ilocked(node);
if (node->proc)
binder_inner_proc_unlock(node->proc);
else
spin_unlock(&binder_dead_nodes_lock);
binder_node_unlock(node);
}
/**
* binder_dec_node_tmpref() - remove a temporary reference on node
* @node: node to reference
*
* Release temporary reference on node taken via binder_inc_node_tmpref()
*/
static void binder_dec_node_tmpref(struct binder_node *node)
{
bool free_node;
binder_node_inner_lock(node);
if (!node->proc)
spin_lock(&binder_dead_nodes_lock);
node->tmp_refs--;
BUG_ON(node->tmp_refs < 0);
if (!node->proc)
spin_unlock(&binder_dead_nodes_lock);
/*
* Call binder_dec_node() to check if all refcounts are 0
* and cleanup is needed. Calling with strong=0 and internal=1
* causes no actual reference to be released in binder_dec_node().
* If that changes, a change is needed here too.
*/
free_node = binder_dec_node_nilocked(node, 0, 1);
binder_node_inner_unlock(node);
if (free_node)
binder_free_node(node);
}
static void binder_put_node(struct binder_node *node)
{
binder_dec_node_tmpref(node);
}
static struct binder_ref *binder_get_ref_olocked(struct binder_proc *proc,
u32 desc, bool need_strong_ref)
{
struct rb_node *n = proc->refs_by_desc.rb_node;
struct binder_ref *ref;
while (n) {
ref = rb_entry(n, struct binder_ref, rb_node_desc);
if (desc < ref->data.desc) {
n = n->rb_left;
} else if (desc > ref->data.desc) {
n = n->rb_right;
} else if (need_strong_ref && !ref->data.strong) {
binder_user_error("tried to use weak ref as strong ref\n");
return NULL;
} else {
return ref;
}
}
return NULL;
}
/**
* binder_get_ref_for_node_olocked() - get the ref associated with given node
* @proc: binder_proc that owns the ref
* @node: binder_node of target
* @new_ref: newly allocated binder_ref to be initialized or %NULL
*
* Look up the ref for the given node and return it if it exists
*
* If it doesn't exist and the caller provides a newly allocated
* ref, initialize the fields of the newly allocated ref and insert
* into the given proc rb_trees and node refs list.
*
* Return: the ref for node. It is possible that another thread
* allocated/initialized the ref first in which case the
* returned ref would be different than the passed-in
* new_ref. new_ref must be kfree'd by the caller in
* this case.
*/
static struct binder_ref *binder_get_ref_for_node_olocked(
struct binder_proc *proc,
struct binder_node *node,
struct binder_ref *new_ref)
{
struct binder_context *context = proc->context;
struct rb_node **p = &proc->refs_by_node.rb_node;
struct rb_node *parent = NULL;
struct binder_ref *ref;
struct rb_node *n;
while (*p) {
parent = *p;
ref = rb_entry(parent, struct binder_ref, rb_node_node);
if (node < ref->node)
p = &(*p)->rb_left;
else if (node > ref->node)
p = &(*p)->rb_right;
else
return ref;
}
if (!new_ref)
return NULL;
binder_stats_created(BINDER_STAT_REF);
new_ref->data.debug_id = atomic_inc_return(&binder_last_id);
new_ref->proc = proc;
new_ref->node = node;
rb_link_node(&new_ref->rb_node_node, parent, p);
rb_insert_color(&new_ref->rb_node_node, &proc->refs_by_node);
new_ref->data.desc = (node == context->binder_context_mgr_node) ? 0 : 1;
for (n = rb_first(&proc->refs_by_desc); n != NULL; n = rb_next(n)) {
ref = rb_entry(n, struct binder_ref, rb_node_desc);
if (ref->data.desc > new_ref->data.desc)
break;
new_ref->data.desc = ref->data.desc + 1;
}
p = &proc->refs_by_desc.rb_node;
while (*p) {
parent = *p;
ref = rb_entry(parent, struct binder_ref, rb_node_desc);
if (new_ref->data.desc < ref->data.desc)
p = &(*p)->rb_left;
else if (new_ref->data.desc > ref->data.desc)
p = &(*p)->rb_right;
else
BUG();
}
rb_link_node(&new_ref->rb_node_desc, parent, p);
rb_insert_color(&new_ref->rb_node_desc, &proc->refs_by_desc);
binder_node_lock(node);
hlist_add_head(&new_ref->node_entry, &node->refs);
binder_debug(BINDER_DEBUG_INTERNAL_REFS,
"%d new ref %d desc %d for node %d\n",
proc->pid, new_ref->data.debug_id, new_ref->data.desc,
node->debug_id);
binder_node_unlock(node);
return new_ref;
}
static void binder_cleanup_ref_olocked(struct binder_ref *ref)
{
bool delete_node = false;
binder_debug(BINDER_DEBUG_INTERNAL_REFS,
"%d delete ref %d desc %d for node %d\n",
ref->proc->pid, ref->data.debug_id, ref->data.desc,
ref->node->debug_id);
rb_erase(&ref->rb_node_desc, &ref->proc->refs_by_desc);
rb_erase(&ref->rb_node_node, &ref->proc->refs_by_node);
binder_node_inner_lock(ref->node);
if (ref->data.strong)
binder_dec_node_nilocked(ref->node, 1, 1);
hlist_del(&ref->node_entry);
delete_node = binder_dec_node_nilocked(ref->node, 0, 1);
binder_node_inner_unlock(ref->node);
/*
* Clear ref->node unless we want the caller to free the node
*/
if (!delete_node) {
/*
* The caller uses ref->node to determine
* whether the node needs to be freed. Clear
* it since the node is still alive.
*/
ref->node = NULL;
}
if (ref->death) {
binder_debug(BINDER_DEBUG_DEAD_BINDER,
"%d delete ref %d desc %d has death notification\n",
ref->proc->pid, ref->data.debug_id,
ref->data.desc);
binder_dequeue_work(ref->proc, &ref->death->work);
binder_stats_deleted(BINDER_STAT_DEATH);
}
binder_stats_deleted(BINDER_STAT_REF);
}
/**
* binder_inc_ref_olocked() - increment the ref for given handle
* @ref: ref to be incremented
* @strong: if true, strong increment, else weak
* @target_list: list to queue node work on
*
* Increment the ref. @ref->proc->outer_lock must be held on entry
*
* Return: 0, if successful, else errno
*/
static int binder_inc_ref_olocked(struct binder_ref *ref, int strong,
struct list_head *target_list)
{
int ret;
if (strong) {
if (ref->data.strong == 0) {
ret = binder_inc_node(ref->node, 1, 1, target_list);
if (ret)
return ret;
}
ref->data.strong++;
} else {
if (ref->data.weak == 0) {
ret = binder_inc_node(ref->node, 0, 1, target_list);
if (ret)
return ret;
}
ref->data.weak++;
}
return 0;
}
/**
* binder_dec_ref() - dec the ref for given handle
* @ref: ref to be decremented
* @strong: if true, strong decrement, else weak
*
* Decrement the ref.
*
* Return: true if ref is cleaned up and ready to be freed
*/
static bool binder_dec_ref_olocked(struct binder_ref *ref, int strong)
{
if (strong) {
if (ref->data.strong == 0) {
binder_user_error("%d invalid dec strong, ref %d desc %d s %d w %d\n",
ref->proc->pid, ref->data.debug_id,
ref->data.desc, ref->data.strong,
ref->data.weak);
return false;
}
ref->data.strong--;
if (ref->data.strong == 0)
binder_dec_node(ref->node, strong, 1);
} else {
if (ref->data.weak == 0) {
binder_user_error("%d invalid dec weak, ref %d desc %d s %d w %d\n",
ref->proc->pid, ref->data.debug_id,
ref->data.desc, ref->data.strong,
ref->data.weak);
return false;
}
ref->data.weak--;
}
if (ref->data.strong == 0 && ref->data.weak == 0) {
binder_cleanup_ref_olocked(ref);
return true;
}
return false;
}
/**
* binder_get_node_from_ref() - get the node from the given proc/desc
* @proc: proc containing the ref
* @desc: the handle associated with the ref
* @need_strong_ref: if true, only return node if ref is strong
* @rdata: the id/refcount data for the ref
*
* Given a proc and ref handle, return the associated binder_node
*
* Return: a binder_node or NULL if not found or not strong when strong required
*/
static struct binder_node *binder_get_node_from_ref(
struct binder_proc *proc,
u32 desc, bool need_strong_ref,
struct binder_ref_data *rdata)
{
struct binder_node *node;
struct binder_ref *ref;
binder_proc_lock(proc);
ref = binder_get_ref_olocked(proc, desc, need_strong_ref);
if (!ref)
goto err_no_ref;
node = ref->node;
/*
* Take an implicit reference on the node to ensure
* it stays alive until the call to binder_put_node()
*/
binder_inc_node_tmpref(node);
if (rdata)
*rdata = ref->data;
binder_proc_unlock(proc);
return node;
err_no_ref:
binder_proc_unlock(proc);
return NULL;
}
/**
* binder_free_ref() - free the binder_ref
* @ref: ref to free
*
* Free the binder_ref. Free the binder_node indicated by ref->node
* (if non-NULL) and the binder_ref_death indicated by ref->death.
*/
static void binder_free_ref(struct binder_ref *ref)
{
if (ref->node)
binder_free_node(ref->node);
kfree(ref->death);
kfree(ref);
}
/**
* binder_update_ref_for_handle() - inc/dec the ref for given handle
* @proc: proc containing the ref
* @desc: the handle associated with the ref
* @increment: true=inc reference, false=dec reference
* @strong: true=strong reference, false=weak reference
* @rdata: the id/refcount data for the ref
*
* Given a proc and ref handle, increment or decrement the ref
* according to "increment" arg.
*
* Return: 0 if successful, else errno
*/
static int binder_update_ref_for_handle(struct binder_proc *proc,
uint32_t desc, bool increment, bool strong,
struct binder_ref_data *rdata)
{
int ret = 0;
struct binder_ref *ref;
bool delete_ref = false;
binder_proc_lock(proc);
ref = binder_get_ref_olocked(proc, desc, strong);
if (!ref) {
ret = -EINVAL;
goto err_no_ref;
}
if (increment)
ret = binder_inc_ref_olocked(ref, strong, NULL);
else
delete_ref = binder_dec_ref_olocked(ref, strong);
if (rdata)
*rdata = ref->data;
binder_proc_unlock(proc);
if (delete_ref)
binder_free_ref(ref);
return ret;
err_no_ref:
binder_proc_unlock(proc);
return ret;
}
/**
* binder_dec_ref_for_handle() - dec the ref for given handle
* @proc: proc containing the ref
* @desc: the handle associated with the ref
* @strong: true=strong reference, false=weak reference
* @rdata: the id/refcount data for the ref
*
* Just calls binder_update_ref_for_handle() to decrement the ref.
*
* Return: 0 if successful, else errno
*/
static int binder_dec_ref_for_handle(struct binder_proc *proc,
uint32_t desc, bool strong, struct binder_ref_data *rdata)
{
return binder_update_ref_for_handle(proc, desc, false, strong, rdata);
}
/**
* binder_inc_ref_for_node() - increment the ref for given proc/node
* @proc: proc containing the ref
* @node: target node
* @strong: true=strong reference, false=weak reference
* @target_list: worklist to use if node is incremented
* @rdata: the id/refcount data for the ref
*
* Given a proc and node, increment the ref. Create the ref if it
* doesn't already exist
*
* Return: 0 if successful, else errno
*/
static int binder_inc_ref_for_node(struct binder_proc *proc,
struct binder_node *node,
bool strong,
struct list_head *target_list,
struct binder_ref_data *rdata)
{
struct binder_ref *ref;
struct binder_ref *new_ref = NULL;
int ret = 0;
binder_proc_lock(proc);
ref = binder_get_ref_for_node_olocked(proc, node, NULL);
if (!ref) {
binder_proc_unlock(proc);
new_ref = kzalloc(sizeof(*ref), GFP_KERNEL);
if (!new_ref)
return -ENOMEM;
binder_proc_lock(proc);
ref = binder_get_ref_for_node_olocked(proc, node, new_ref);
}
ret = binder_inc_ref_olocked(ref, strong, target_list);
*rdata = ref->data;
binder_proc_unlock(proc);
if (new_ref && ref != new_ref)
/*
* Another thread created the ref first so
* free the one we allocated
*/
kfree(new_ref);
return ret;
}
static void binder_pop_transaction_ilocked(struct binder_thread *target_thread,
struct binder_transaction *t)
{
BUG_ON(!target_thread);
assert_spin_locked(&target_thread->proc->inner_lock);
BUG_ON(target_thread->transaction_stack != t);
BUG_ON(target_thread->transaction_stack->from != target_thread);
target_thread->transaction_stack =
target_thread->transaction_stack->from_parent;
t->from = NULL;
}
/**
* binder_thread_dec_tmpref() - decrement thread->tmp_ref
* @thread: thread to decrement
*
* A thread needs to be kept alive while being used to create or
* handle a transaction. binder_get_txn_from() is used to safely
* extract t->from from a binder_transaction and keep the thread
* indicated by t->from from being freed. When done with that
* binder_thread, this function is called to decrement the
* tmp_ref and free if appropriate (thread has been released
* and no transaction being processed by the driver)
*/
static void binder_thread_dec_tmpref(struct binder_thread *thread)
{
/*
* atomic is used to protect the counter value while
* it cannot reach zero or thread->is_dead is false
*/
binder_inner_proc_lock(thread->proc);
atomic_dec(&thread->tmp_ref);
if (thread->is_dead && !atomic_read(&thread->tmp_ref)) {
binder_inner_proc_unlock(thread->proc);
binder_free_thread(thread);
return;
}
binder_inner_proc_unlock(thread->proc);
}
/**
* binder_proc_dec_tmpref() - decrement proc->tmp_ref
* @proc: proc to decrement
*
* A binder_proc needs to be kept alive while being used to create or
* handle a transaction. proc->tmp_ref is incremented when
* creating a new transaction or the binder_proc is currently in-use
* by threads that are being released. When done with the binder_proc,
* this function is called to decrement the counter and free the
* proc if appropriate (proc has been released, all threads have
* been released and not currenly in-use to process a transaction).
*/
static void binder_proc_dec_tmpref(struct binder_proc *proc)
{
binder_inner_proc_lock(proc);
proc->tmp_ref--;
if (proc->is_dead && RB_EMPTY_ROOT(&proc->threads) &&
!proc->tmp_ref) {
binder_inner_proc_unlock(proc);
binder_free_proc(proc);
return;
}
binder_inner_proc_unlock(proc);
}
/**
* binder_get_txn_from() - safely extract the "from" thread in transaction
* @t: binder transaction for t->from
*
* Atomically return the "from" thread and increment the tmp_ref
* count for the thread to ensure it stays alive until
* binder_thread_dec_tmpref() is called.
*
* Return: the value of t->from
*/
static struct binder_thread *binder_get_txn_from(
struct binder_transaction *t)
{
struct binder_thread *from;
spin_lock(&t->lock);
from = t->from;
if (from)
atomic_inc(&from->tmp_ref);
spin_unlock(&t->lock);
return from;
}
/**
* binder_get_txn_from_and_acq_inner() - get t->from and acquire inner lock
* @t: binder transaction for t->from
*
* Same as binder_get_txn_from() except it also acquires the proc->inner_lock
* to guarantee that the thread cannot be released while operating on it.
* The caller must call binder_inner_proc_unlock() to release the inner lock
* as well as call binder_dec_thread_txn() to release the reference.
*
* Return: the value of t->from
*/
static struct binder_thread *binder_get_txn_from_and_acq_inner(
struct binder_transaction *t)
{
struct binder_thread *from;
from = binder_get_txn_from(t);
if (!from)
return NULL;
binder_inner_proc_lock(from->proc);
if (t->from) {
BUG_ON(from != t->from);
return from;
}
binder_inner_proc_unlock(from->proc);
binder_thread_dec_tmpref(from);
return NULL;
}
static void binder_free_transaction(struct binder_transaction *t)
{
if (t->buffer)
t->buffer->transaction = NULL;
kfree(t);
binder_stats_deleted(BINDER_STAT_TRANSACTION);
}
static void binder_send_failed_reply(struct binder_transaction *t,
uint32_t error_code)
{
struct binder_thread *target_thread;
struct binder_transaction *next;
BUG_ON(t->flags & TF_ONE_WAY);
while (1) {
target_thread = binder_get_txn_from_and_acq_inner(t);
if (target_thread) {
binder_debug(BINDER_DEBUG_FAILED_TRANSACTION,
"send failed reply for transaction %d to %d:%d\n",
t->debug_id,
target_thread->proc->pid,
target_thread->pid);
binder_pop_transaction_ilocked(target_thread, t);
if (target_thread->reply_error.cmd == BR_OK) {
target_thread->reply_error.cmd = error_code;
binder_enqueue_work_ilocked(
&target_thread->reply_error.work,
&target_thread->todo);
wake_up_interruptible(&target_thread->wait);
} else {
WARN(1, "Unexpected reply error: %u\n",
target_thread->reply_error.cmd);
}
binder_inner_proc_unlock(target_thread->proc);
binder_thread_dec_tmpref(target_thread);
binder_free_transaction(t);
return;
}
next = t->from_parent;
binder_debug(BINDER_DEBUG_FAILED_TRANSACTION,
"send failed reply for transaction %d, target dead\n",
t->debug_id);
binder_free_transaction(t);
if (next == NULL) {
binder_debug(BINDER_DEBUG_DEAD_BINDER,
"reply failed, no target thread at root\n");
return;
}
t = next;
binder_debug(BINDER_DEBUG_DEAD_BINDER,
"reply failed, no target thread -- retry %d\n",
t->debug_id);
}
}
/**
* binder_validate_object() - checks for a valid metadata object in a buffer.
* @buffer: binder_buffer that we're parsing.
* @offset: offset in the buffer at which to validate an object.
*
* Return: If there's a valid metadata object at @offset in @buffer, the
* size of that object. Otherwise, it returns zero.
*/
static size_t binder_validate_object(struct binder_buffer *buffer, u64 offset)
{
/* Check if we can read a header first */
struct binder_object_header *hdr;
size_t object_size = 0;
if (offset > buffer->data_size - sizeof(*hdr) ||
buffer->data_size < sizeof(*hdr) ||
!IS_ALIGNED(offset, sizeof(u32)))
return 0;
/* Ok, now see if we can read a complete object. */
hdr = (struct binder_object_header *)(buffer->data + offset);
switch (hdr->type) {
case BINDER_TYPE_BINDER:
case BINDER_TYPE_WEAK_BINDER:
case BINDER_TYPE_HANDLE:
case BINDER_TYPE_WEAK_HANDLE:
object_size = sizeof(struct flat_binder_object);
break;
case BINDER_TYPE_FD:
object_size = sizeof(struct binder_fd_object);
break;
case BINDER_TYPE_PTR:
object_size = sizeof(struct binder_buffer_object);
break;
case BINDER_TYPE_FDA:
object_size = sizeof(struct binder_fd_array_object);
break;
default:
return 0;
}
if (offset <= buffer->data_size - object_size &&
buffer->data_size >= object_size)
return object_size;
else
return 0;
}
/**
* binder_validate_ptr() - validates binder_buffer_object in a binder_buffer.
* @b: binder_buffer containing the object
* @index: index in offset array at which the binder_buffer_object is
* located
* @start: points to the start of the offset array
* @num_valid: the number of valid offsets in the offset array
*
* Return: If @index is within the valid range of the offset array
* described by @start and @num_valid, and if there's a valid
* binder_buffer_object at the offset found in index @index
* of the offset array, that object is returned. Otherwise,
* %NULL is returned.
* Note that the offset found in index @index itself is not
* verified; this function assumes that @num_valid elements
* from @start were previously verified to have valid offsets.
*/
static struct binder_buffer_object *binder_validate_ptr(struct binder_buffer *b,
binder_size_t index,
binder_size_t *start,
binder_size_t num_valid)
{
struct binder_buffer_object *buffer_obj;
binder_size_t *offp;
if (index >= num_valid)
return NULL;
offp = start + index;
buffer_obj = (struct binder_buffer_object *)(b->data + *offp);
if (buffer_obj->hdr.type != BINDER_TYPE_PTR)
return NULL;
return buffer_obj;
}
/**
* binder_validate_fixup() - validates pointer/fd fixups happen in order.
* @b: transaction buffer
* @objects_start start of objects buffer
* @buffer: binder_buffer_object in which to fix up
* @offset: start offset in @buffer to fix up
* @last_obj: last binder_buffer_object that we fixed up in
* @last_min_offset: minimum fixup offset in @last_obj
*
* Return: %true if a fixup in buffer @buffer at offset @offset is
* allowed.
*
* For safety reasons, we only allow fixups inside a buffer to happen
* at increasing offsets; additionally, we only allow fixup on the last
* buffer object that was verified, or one of its parents.
*
* Example of what is allowed:
*
* A
* B (parent = A, offset = 0)
* C (parent = A, offset = 16)
* D (parent = C, offset = 0)
* E (parent = A, offset = 32) // min_offset is 16 (C.parent_offset)
*
* Examples of what is not allowed:
*
* Decreasing offsets within the same parent:
* A
* C (parent = A, offset = 16)
* B (parent = A, offset = 0) // decreasing offset within A
*
* Referring to a parent that wasn't the last object or any of its parents:
* A
* B (parent = A, offset = 0)
* C (parent = A, offset = 0)
* C (parent = A, offset = 16)
* D (parent = B, offset = 0) // B is not A or any of A's parents
*/
static bool binder_validate_fixup(struct binder_buffer *b,
binder_size_t *objects_start,
struct binder_buffer_object *buffer,
binder_size_t fixup_offset,
struct binder_buffer_object *last_obj,
binder_size_t last_min_offset)
{
if (!last_obj) {
/* Nothing to fix up in */
return false;
}
while (last_obj != buffer) {
/*
* Safe to retrieve the parent of last_obj, since it
* was already previously verified by the driver.
*/
if ((last_obj->flags & BINDER_BUFFER_FLAG_HAS_PARENT) == 0)
return false;
last_min_offset = last_obj->parent_offset + sizeof(uintptr_t);
last_obj = (struct binder_buffer_object *)
(b->data + *(objects_start + last_obj->parent));
}
return (fixup_offset >= last_min_offset);
}
static void binder_transaction_buffer_release(struct binder_proc *proc,
struct binder_buffer *buffer,
binder_size_t *failed_at)
{
binder_size_t *offp, *off_start, *off_end;
int debug_id = buffer->debug_id;
binder_debug(BINDER_DEBUG_TRANSACTION,
"%d buffer release %d, size %zd-%zd, failed at %p\n",
proc->pid, buffer->debug_id,
buffer->data_size, buffer->offsets_size, failed_at);
if (buffer->target_node)
binder_dec_node(buffer->target_node, 1, 0);
off_start = (binder_size_t *)(buffer->data +
ALIGN(buffer->data_size, sizeof(void *)));
if (failed_at)
off_end = failed_at;
else
off_end = (void *)off_start + buffer->offsets_size;
for (offp = off_start; offp < off_end; offp++) {
struct binder_object_header *hdr;
size_t object_size = binder_validate_object(buffer, *offp);
if (object_size == 0) {
pr_err("transaction release %d bad object at offset %lld, size %zd\n",
debug_id, (u64)*offp, buffer->data_size);
continue;
}
hdr = (struct binder_object_header *)(buffer->data + *offp);
switch (hdr->type) {
case BINDER_TYPE_BINDER:
case BINDER_TYPE_WEAK_BINDER: {
struct flat_binder_object *fp;
struct binder_node *node;
fp = to_flat_binder_object(hdr);
node = binder_get_node(proc, fp->binder);
if (node == NULL) {
pr_err("transaction release %d bad node %016llx\n",
debug_id, (u64)fp->binder);
break;
}
binder_debug(BINDER_DEBUG_TRANSACTION,
" node %d u%016llx\n",
node->debug_id, (u64)node->ptr);
binder_dec_node(node, hdr->type == BINDER_TYPE_BINDER,
0);
binder_put_node(node);
} break;
case BINDER_TYPE_HANDLE:
case BINDER_TYPE_WEAK_HANDLE: {
struct flat_binder_object *fp;
struct binder_ref_data rdata;
int ret;
fp = to_flat_binder_object(hdr);
ret = binder_dec_ref_for_handle(proc, fp->handle,
hdr->type == BINDER_TYPE_HANDLE, &rdata);
if (ret) {
pr_err("transaction release %d bad handle %d, ret = %d\n",
debug_id, fp->handle, ret);
break;
}
binder_debug(BINDER_DEBUG_TRANSACTION,
" ref %d desc %d\n",
rdata.debug_id, rdata.desc);
} break;
case BINDER_TYPE_FD: {
struct binder_fd_object *fp = to_binder_fd_object(hdr);
binder_debug(BINDER_DEBUG_TRANSACTION,
" fd %d\n", fp->fd);
if (failed_at)
task_close_fd(proc, fp->fd);
} break;
case BINDER_TYPE_PTR:
/*
* Nothing to do here, this will get cleaned up when the
* transaction buffer gets freed
*/
break;
case BINDER_TYPE_FDA: {
struct binder_fd_array_object *fda;
struct binder_buffer_object *parent;
uintptr_t parent_buffer;
u32 *fd_array;
size_t fd_index;
binder_size_t fd_buf_size;
fda = to_binder_fd_array_object(hdr);
parent = binder_validate_ptr(buffer, fda->parent,
off_start,
offp - off_start);
if (!parent) {
pr_err("transaction release %d bad parent offset",
debug_id);
continue;
}
/*
* Since the parent was already fixed up, convert it
* back to kernel address space to access it
*/
parent_buffer = parent->buffer -
binder_alloc_get_user_buffer_offset(
&proc->alloc);
fd_buf_size = sizeof(u32) * fda->num_fds;
if (fda->num_fds >= SIZE_MAX / sizeof(u32)) {
pr_err("transaction release %d invalid number of fds (%lld)\n",
debug_id, (u64)fda->num_fds);
continue;
}
if (fd_buf_size > parent->length ||
fda->parent_offset > parent->length - fd_buf_size) {
/* No space for all file descriptors here. */
pr_err("transaction release %d not enough space for %lld fds in buffer\n",
debug_id, (u64)fda->num_fds);
continue;
}
fd_array = (u32 *)(parent_buffer + (uintptr_t)fda->parent_offset);
for (fd_index = 0; fd_index < fda->num_fds; fd_index++)
task_close_fd(proc, fd_array[fd_index]);
} break;
default:
pr_err("transaction release %d bad object type %x\n",
debug_id, hdr->type);
break;
}
}
}
static int binder_translate_binder(struct flat_binder_object *fp,
struct binder_transaction *t,
struct binder_thread *thread)
{
struct binder_node *node;
struct binder_proc *proc = thread->proc;
struct binder_proc *target_proc = t->to_proc;
struct binder_ref_data rdata;
int ret = 0;
node = binder_get_node(proc, fp->binder);
if (!node) {
node = binder_new_node(proc, fp);
if (!node)
return -ENOMEM;
}
if (fp->cookie != node->cookie) {
binder_user_error("%d:%d sending u%016llx node %d, cookie mismatch %016llx != %016llx\n",
proc->pid, thread->pid, (u64)fp->binder,
node->debug_id, (u64)fp->cookie,
(u64)node->cookie);
ret = -EINVAL;
goto done;
}
if (security_binder_transfer_binder(proc->tsk, target_proc->tsk)) {
ret = -EPERM;
goto done;
}
ret = binder_inc_ref_for_node(target_proc, node,
fp->hdr.type == BINDER_TYPE_BINDER,
&thread->todo, &rdata);
if (ret)
goto done;
if (fp->hdr.type == BINDER_TYPE_BINDER)
fp->hdr.type = BINDER_TYPE_HANDLE;
else
fp->hdr.type = BINDER_TYPE_WEAK_HANDLE;
fp->binder = 0;
fp->handle = rdata.desc;
fp->cookie = 0;
trace_binder_transaction_node_to_ref(t, node, &rdata);
binder_debug(BINDER_DEBUG_TRANSACTION,
" node %d u%016llx -> ref %d desc %d\n",
node->debug_id, (u64)node->ptr,
rdata.debug_id, rdata.desc);
done:
binder_put_node(node);
return ret;
}
static int binder_translate_handle(struct flat_binder_object *fp,
struct binder_transaction *t,
struct binder_thread *thread)
{
struct binder_proc *proc = thread->proc;
struct binder_proc *target_proc = t->to_proc;
struct binder_node *node;
struct binder_ref_data src_rdata;
int ret = 0;
node = binder_get_node_from_ref(proc, fp->handle,
fp->hdr.type == BINDER_TYPE_HANDLE, &src_rdata);
if (!node) {
binder_user_error("%d:%d got transaction with invalid handle, %d\n",
proc->pid, thread->pid, fp->handle);
return -EINVAL;
}
if (security_binder_transfer_binder(proc->tsk, target_proc->tsk)) {
ret = -EPERM;
goto done;
}
binder_node_lock(node);
if (node->proc == target_proc) {
if (fp->hdr.type == BINDER_TYPE_HANDLE)
fp->hdr.type = BINDER_TYPE_BINDER;
else
fp->hdr.type = BINDER_TYPE_WEAK_BINDER;
fp->binder = node->ptr;
fp->cookie = node->cookie;
if (node->proc)
binder_inner_proc_lock(node->proc);
binder_inc_node_nilocked(node,
fp->hdr.type == BINDER_TYPE_BINDER,
0, NULL);
if (node->proc)
binder_inner_proc_unlock(node->proc);
trace_binder_transaction_ref_to_node(t, node, &src_rdata);
binder_debug(BINDER_DEBUG_TRANSACTION,
" ref %d desc %d -> node %d u%016llx\n",
src_rdata.debug_id, src_rdata.desc, node->debug_id,
(u64)node->ptr);
binder_node_unlock(node);
} else {
struct binder_ref_data dest_rdata;
binder_node_unlock(node);
ret = binder_inc_ref_for_node(target_proc, node,
fp->hdr.type == BINDER_TYPE_HANDLE,
NULL, &dest_rdata);
if (ret)
goto done;
fp->binder = 0;
fp->handle = dest_rdata.desc;
fp->cookie = 0;
trace_binder_transaction_ref_to_ref(t, node, &src_rdata,
&dest_rdata);
binder_debug(BINDER_DEBUG_TRANSACTION,
" ref %d desc %d -> ref %d desc %d (node %d)\n",
src_rdata.debug_id, src_rdata.desc,
dest_rdata.debug_id, dest_rdata.desc,
node->debug_id);
}
done:
binder_put_node(node);
return ret;
}
static int binder_translate_fd(int fd,
struct binder_transaction *t,
struct binder_thread *thread,
struct binder_transaction *in_reply_to)
{
struct binder_proc *proc = thread->proc;
struct binder_proc *target_proc = t->to_proc;
int target_fd;
struct file *file;
int ret;
bool target_allows_fd;
if (in_reply_to)
target_allows_fd = !!(in_reply_to->flags & TF_ACCEPT_FDS);
else
target_allows_fd = t->buffer->target_node->accept_fds;
if (!target_allows_fd) {
binder_user_error("%d:%d got %s with fd, %d, but target does not allow fds\n",
proc->pid, thread->pid,
in_reply_to ? "reply" : "transaction",
fd);
ret = -EPERM;
goto err_fd_not_accepted;
}
file = fget(fd);
if (!file) {
binder_user_error("%d:%d got transaction with invalid fd, %d\n",
proc->pid, thread->pid, fd);
ret = -EBADF;
goto err_fget;
}
ret = security_binder_transfer_file(proc->tsk, target_proc->tsk, file);
if (ret < 0) {
ret = -EPERM;
goto err_security;
}
target_fd = task_get_unused_fd_flags(target_proc, O_CLOEXEC);
if (target_fd < 0) {
ret = -ENOMEM;
goto err_get_unused_fd;
}
task_fd_install(target_proc, target_fd, file);
trace_binder_transaction_fd(t, fd, target_fd);
binder_debug(BINDER_DEBUG_TRANSACTION, " fd %d -> %d\n",
fd, target_fd);
return target_fd;
err_get_unused_fd:
err_security:
fput(file);
err_fget:
err_fd_not_accepted:
return ret;
}
static int binder_translate_fd_array(struct binder_fd_array_object *fda,
struct binder_buffer_object *parent,
struct binder_transaction *t,
struct binder_thread *thread,
struct binder_transaction *in_reply_to)
{
binder_size_t fdi, fd_buf_size, num_installed_fds;
int target_fd;
uintptr_t parent_buffer;
u32 *fd_array;
struct binder_proc *proc = thread->proc;
struct binder_proc *target_proc = t->to_proc;
fd_buf_size = sizeof(u32) * fda->num_fds;
if (fda->num_fds >= SIZE_MAX / sizeof(u32)) {
binder_user_error("%d:%d got transaction with invalid number of fds (%lld)\n",
proc->pid, thread->pid, (u64)fda->num_fds);
return -EINVAL;
}
if (fd_buf_size > parent->length ||
fda->parent_offset > parent->length - fd_buf_size) {
/* No space for all file descriptors here. */
binder_user_error("%d:%d not enough space to store %lld fds in buffer\n",
proc->pid, thread->pid, (u64)fda->num_fds);
return -EINVAL;
}
/*
* Since the parent was already fixed up, convert it
* back to the kernel address space to access it
*/
parent_buffer = parent->buffer -
binder_alloc_get_user_buffer_offset(&target_proc->alloc);
fd_array = (u32 *)(parent_buffer + (uintptr_t)fda->parent_offset);
if (!IS_ALIGNED((unsigned long)fd_array, sizeof(u32))) {
binder_user_error("%d:%d parent offset not aligned correctly.\n",
proc->pid, thread->pid);
return -EINVAL;
}
for (fdi = 0; fdi < fda->num_fds; fdi++) {
target_fd = binder_translate_fd(fd_array[fdi], t, thread,
in_reply_to);
if (target_fd < 0)
goto err_translate_fd_failed;
fd_array[fdi] = target_fd;
}
return 0;
err_translate_fd_failed:
/*
* Failed to allocate fd or security error, free fds
* installed so far.
*/
num_installed_fds = fdi;
for (fdi = 0; fdi < num_installed_fds; fdi++)
task_close_fd(target_proc, fd_array[fdi]);
return target_fd;
}
static int binder_fixup_parent(struct binder_transaction *t,
struct binder_thread *thread,
struct binder_buffer_object *bp,
binder_size_t *off_start,
binder_size_t num_valid,
struct binder_buffer_object *last_fixup_obj,
binder_size_t last_fixup_min_off)
{
struct binder_buffer_object *parent;
u8 *parent_buffer;
struct binder_buffer *b = t->buffer;
struct binder_proc *proc = thread->proc;
struct binder_proc *target_proc = t->to_proc;
if (!(bp->flags & BINDER_BUFFER_FLAG_HAS_PARENT))
return 0;
parent = binder_validate_ptr(b, bp->parent, off_start, num_valid);
if (!parent) {
binder_user_error("%d:%d got transaction with invalid parent offset or type\n",
proc->pid, thread->pid);
return -EINVAL;
}
if (!binder_validate_fixup(b, off_start,
parent, bp->parent_offset,
last_fixup_obj,
last_fixup_min_off)) {
binder_user_error("%d:%d got transaction with out-of-order buffer fixup\n",
proc->pid, thread->pid);
return -EINVAL;
}
if (parent->length < sizeof(binder_uintptr_t) ||
bp->parent_offset > parent->length - sizeof(binder_uintptr_t)) {
/* No space for a pointer here! */
binder_user_error("%d:%d got transaction with invalid parent offset\n",
proc->pid, thread->pid);
return -EINVAL;
}
parent_buffer = (u8 *)((uintptr_t)parent->buffer -
binder_alloc_get_user_buffer_offset(
&target_proc->alloc));
*(binder_uintptr_t *)(parent_buffer + bp->parent_offset) = bp->buffer;
return 0;
}
/**
* binder_proc_transaction() - sends a transaction to a process and wakes it up
* @t: transaction to send
* @proc: process to send the transaction to
* @thread: thread in @proc to send the transaction to (may be NULL)
*
* This function queues a transaction to the specified process. It will try
* to find a thread in the target process to handle the transaction and
* wake it up. If no thread is found, the work is queued to the proc
* waitqueue.
*
* If the @thread parameter is not NULL, the transaction is always queued
* to the waitlist of that specific thread.
*
* Return: true if the transactions was successfully queued
* false if the target process or thread is dead
*/
static bool binder_proc_transaction(struct binder_transaction *t,
struct binder_proc *proc,
struct binder_thread *thread)
{
struct list_head *target_list = NULL;
struct binder_node *node = t->buffer->target_node;
bool oneway = !!(t->flags & TF_ONE_WAY);
bool wakeup = true;
BUG_ON(!node);
binder_node_lock(node);
if (oneway) {
BUG_ON(thread);
if (node->has_async_transaction) {
target_list = &node->async_todo;
wakeup = false;
} else {
node->has_async_transaction = 1;
}
}
binder_inner_proc_lock(proc);
if (proc->is_dead || (thread && thread->is_dead)) {
binder_inner_proc_unlock(proc);
binder_node_unlock(node);
return false;
}
if (!thread && !target_list)
thread = binder_select_thread_ilocked(proc);
if (thread)
target_list = &thread->todo;
else if (!target_list)
target_list = &proc->todo;
else
BUG_ON(target_list != &node->async_todo);
binder_enqueue_work_ilocked(&t->work, target_list);
if (wakeup)
binder_wakeup_thread_ilocked(proc, thread, !oneway /* sync */);
binder_inner_proc_unlock(proc);
binder_node_unlock(node);
return true;
}
static void binder_transaction(struct binder_proc *proc,
struct binder_thread *thread,
struct binder_transaction_data *tr, int reply,
binder_size_t extra_buffers_size)
{
int ret;
struct binder_transaction *t;
struct binder_work *tcomplete;
binder_size_t *offp, *off_end, *off_start;
binder_size_t off_min;
u8 *sg_bufp, *sg_buf_end;
struct binder_proc *target_proc = NULL;
struct binder_thread *target_thread = NULL;
struct binder_node *target_node = NULL;
struct binder_transaction *in_reply_to = NULL;
struct binder_transaction_log_entry *e;
uint32_t return_error = 0;
uint32_t return_error_param = 0;
uint32_t return_error_line = 0;
struct binder_buffer_object *last_fixup_obj = NULL;
binder_size_t last_fixup_min_off = 0;
struct binder_context *context = proc->context;
int t_debug_id = atomic_inc_return(&binder_last_id);
e = binder_transaction_log_add(&binder_transaction_log);
e->debug_id = t_debug_id;
e->call_type = reply ? 2 : !!(tr->flags & TF_ONE_WAY);
e->from_proc = proc->pid;
e->from_thread = thread->pid;
e->target_handle = tr->target.handle;
e->data_size = tr->data_size;
e->offsets_size = tr->offsets_size;
e->context_name = proc->context->name;
if (reply) {
binder_inner_proc_lock(proc);
in_reply_to = thread->transaction_stack;
if (in_reply_to == NULL) {
binder_inner_proc_unlock(proc);
binder_user_error("%d:%d got reply transaction with no transaction stack\n",
proc->pid, thread->pid);
return_error = BR_FAILED_REPLY;
return_error_param = -EPROTO;
return_error_line = __LINE__;
goto err_empty_call_stack;
}
if (in_reply_to->to_thread != thread) {
spin_lock(&in_reply_to->lock);
binder_user_error("%d:%d got reply transaction with bad transaction stack, transaction %d has target %d:%d\n",
proc->pid, thread->pid, in_reply_to->debug_id,
in_reply_to->to_proc ?
in_reply_to->to_proc->pid : 0,
in_reply_to->to_thread ?
in_reply_to->to_thread->pid : 0);
spin_unlock(&in_reply_to->lock);
binder_inner_proc_unlock(proc);
return_error = BR_FAILED_REPLY;
return_error_param = -EPROTO;
return_error_line = __LINE__;
in_reply_to = NULL;
goto err_bad_call_stack;
}
thread->transaction_stack = in_reply_to->to_parent;
binder_inner_proc_unlock(proc);
binder_set_nice(in_reply_to->saved_priority);
target_thread = binder_get_txn_from_and_acq_inner(in_reply_to);
if (target_thread == NULL) {
return_error = BR_DEAD_REPLY;
return_error_line = __LINE__;
goto err_dead_binder;
}
if (target_thread->transaction_stack != in_reply_to) {
binder_user_error("%d:%d got reply transaction with bad target transaction stack %d, expected %d\n",
proc->pid, thread->pid,
target_thread->transaction_stack ?
target_thread->transaction_stack->debug_id : 0,
in_reply_to->debug_id);
binder_inner_proc_unlock(target_thread->proc);
return_error = BR_FAILED_REPLY;
return_error_param = -EPROTO;
return_error_line = __LINE__;
in_reply_to = NULL;
target_thread = NULL;
goto err_dead_binder;
}
target_proc = target_thread->proc;
target_proc->tmp_ref++;
binder_inner_proc_unlock(target_thread->proc);
} else {
if (tr->target.handle) {
struct binder_ref *ref;
/*
* There must already be a strong ref
* on this node. If so, do a strong
* increment on the node to ensure it
* stays alive until the transaction is
* done.
*/
binder_proc_lock(proc);
ref = binder_get_ref_olocked(proc, tr->target.handle,
true);
if (ref) {
binder_inc_node(ref->node, 1, 0, NULL);
target_node = ref->node;
}
binder_proc_unlock(proc);
if (target_node == NULL) {
binder_user_error("%d:%d got transaction to invalid handle\n",
proc->pid, thread->pid);
return_error = BR_FAILED_REPLY;
return_error_param = -EINVAL;
return_error_line = __LINE__;
goto err_invalid_target_handle;
}
} else {
mutex_lock(&context->context_mgr_node_lock);
target_node = context->binder_context_mgr_node;
if (target_node == NULL) {
return_error = BR_DEAD_REPLY;
mutex_unlock(&context->context_mgr_node_lock);
return_error_line = __LINE__;
goto err_no_context_mgr_node;
}
binder_inc_node(target_node, 1, 0, NULL);
mutex_unlock(&context->context_mgr_node_lock);
}
e->to_node = target_node->debug_id;
binder_node_lock(target_node);
target_proc = target_node->proc;
if (target_proc == NULL) {
binder_node_unlock(target_node);
return_error = BR_DEAD_REPLY;
return_error_line = __LINE__;
goto err_dead_binder;
}
binder_inner_proc_lock(target_proc);
target_proc->tmp_ref++;
binder_inner_proc_unlock(target_proc);
binder_node_unlock(target_node);
if (security_binder_transaction(proc->tsk,
target_proc->tsk) < 0) {
return_error = BR_FAILED_REPLY;
return_error_param = -EPERM;
return_error_line = __LINE__;
goto err_invalid_target_handle;
}
binder_inner_proc_lock(proc);
if (!(tr->flags & TF_ONE_WAY) && thread->transaction_stack) {
struct binder_transaction *tmp;
tmp = thread->transaction_stack;
if (tmp->to_thread != thread) {
spin_lock(&tmp->lock);
binder_user_error("%d:%d got new transaction with bad transaction stack, transaction %d has target %d:%d\n",
proc->pid, thread->pid, tmp->debug_id,
tmp->to_proc ? tmp->to_proc->pid : 0,
tmp->to_thread ?
tmp->to_thread->pid : 0);
spin_unlock(&tmp->lock);
binder_inner_proc_unlock(proc);
return_error = BR_FAILED_REPLY;
return_error_param = -EPROTO;
return_error_line = __LINE__;
goto err_bad_call_stack;
}
while (tmp) {
struct binder_thread *from;
spin_lock(&tmp->lock);
from = tmp->from;
if (from && from->proc == target_proc) {
atomic_inc(&from->tmp_ref);
target_thread = from;
spin_unlock(&tmp->lock);
break;
}
spin_unlock(&tmp->lock);
tmp = tmp->from_parent;
}
}
binder_inner_proc_unlock(proc);
}
if (target_thread)
e->to_thread = target_thread->pid;
e->to_proc = target_proc->pid;
/* TODO: reuse incoming transaction for reply */
t = kzalloc(sizeof(*t), GFP_KERNEL);
if (t == NULL) {
return_error = BR_FAILED_REPLY;
return_error_param = -ENOMEM;
return_error_line = __LINE__;
goto err_alloc_t_failed;
}
binder_stats_created(BINDER_STAT_TRANSACTION);
spin_lock_init(&t->lock);
tcomplete = kzalloc(sizeof(*tcomplete), GFP_KERNEL);
if (tcomplete == NULL) {
return_error = BR_FAILED_REPLY;
return_error_param = -ENOMEM;
return_error_line = __LINE__;
goto err_alloc_tcomplete_failed;
}
binder_stats_created(BINDER_STAT_TRANSACTION_COMPLETE);
t->debug_id = t_debug_id;
if (reply)
binder_debug(BINDER_DEBUG_TRANSACTION,
"%d:%d BC_REPLY %d -> %d:%d, data %016llx-%016llx size %lld-%lld-%lld\n",
proc->pid, thread->pid, t->debug_id,
target_proc->pid, target_thread->pid,
(u64)tr->data.ptr.buffer,
(u64)tr->data.ptr.offsets,
(u64)tr->data_size, (u64)tr->offsets_size,
(u64)extra_buffers_size);
else
binder_debug(BINDER_DEBUG_TRANSACTION,
"%d:%d BC_TRANSACTION %d -> %d - node %d, data %016llx-%016llx size %lld-%lld-%lld\n",
proc->pid, thread->pid, t->debug_id,
target_proc->pid, target_node->debug_id,
(u64)tr->data.ptr.buffer,
(u64)tr->data.ptr.offsets,
(u64)tr->data_size, (u64)tr->offsets_size,
(u64)extra_buffers_size);
if (!reply && !(tr->flags & TF_ONE_WAY))
t->from = thread;
else
t->from = NULL;
t->sender_euid = task_euid(proc->tsk);
t->to_proc = target_proc;
t->to_thread = target_thread;
t->code = tr->code;
t->flags = tr->flags;
t->priority = task_nice(current);
trace_binder_transaction(reply, t, target_node);
t->buffer = binder_alloc_new_buf(&target_proc->alloc, tr->data_size,
tr->offsets_size, extra_buffers_size,
!reply && (t->flags & TF_ONE_WAY));
if (IS_ERR(t->buffer)) {
/*
* -ESRCH indicates VMA cleared. The target is dying.
*/
return_error_param = PTR_ERR(t->buffer);
return_error = return_error_param == -ESRCH ?
BR_DEAD_REPLY : BR_FAILED_REPLY;
return_error_line = __LINE__;
t->buffer = NULL;
goto err_binder_alloc_buf_failed;
}
t->buffer->allow_user_free = 0;
t->buffer->debug_id = t->debug_id;
t->buffer->transaction = t;
t->buffer->target_node = target_node;
trace_binder_transaction_alloc_buf(t->buffer);
off_start = (binder_size_t *)(t->buffer->data +
ALIGN(tr->data_size, sizeof(void *)));
offp = off_start;
if (copy_from_user(t->buffer->data, (const void __user *)(uintptr_t)
tr->data.ptr.buffer, tr->data_size)) {
binder_user_error("%d:%d got transaction with invalid data ptr\n",
proc->pid, thread->pid);
return_error = BR_FAILED_REPLY;
return_error_param = -EFAULT;
return_error_line = __LINE__;
goto err_copy_data_failed;
}
if (copy_from_user(offp, (const void __user *)(uintptr_t)
tr->data.ptr.offsets, tr->offsets_size)) {
binder_user_error("%d:%d got transaction with invalid offsets ptr\n",
proc->pid, thread->pid);
return_error = BR_FAILED_REPLY;
return_error_param = -EFAULT;
return_error_line = __LINE__;
goto err_copy_data_failed;
}
if (!IS_ALIGNED(tr->offsets_size, sizeof(binder_size_t))) {
binder_user_error("%d:%d got transaction with invalid offsets size, %lld\n",
proc->pid, thread->pid, (u64)tr->offsets_size);
return_error = BR_FAILED_REPLY;
return_error_param = -EINVAL;
return_error_line = __LINE__;
goto err_bad_offset;
}
if (!IS_ALIGNED(extra_buffers_size, sizeof(u64))) {
binder_user_error("%d:%d got transaction with unaligned buffers size, %lld\n",