binder: add protection for non-perf cases

Add binder_dead_nodes_lock, binder_procs_lock, and
binder_context_mgr_node_lock to protect the associated global lists

Signed-off-by: Todd Kjos <tkjos@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 63 insertions, 18 deletions

diff --git a/drivers/android/binder.c b/drivers/android/binder.c
index 10fda7ab9fa5..fb484c6acd3e 100644
--- a/drivers/android/binder.c
+++ b/drivers/android/binder.c
@@ -46,12 +46,16 @@
 #include "binder_trace.h"
 
 static DEFINE_MUTEX(binder_main_lock);
+
+static HLIST_HEAD(binder_deferred_list);
 static DEFINE_MUTEX(binder_deferred_lock);
 
 static HLIST_HEAD(binder_devices);
 static HLIST_HEAD(binder_procs);
-static HLIST_HEAD(binder_deferred_list);
+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;
@@ -219,6 +223,8 @@ static struct binder_transaction_log_entry *binder_transaction_log_add(
 
 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;
 };
@@ -570,7 +576,9 @@ static int binder_dec_node(struct binder_node *node, int strong, int internal)
                                              "refless node %d deleted\n",
                                              node->debug_id);
                         } else {
+                                spin_lock(&binder_dead_nodes_lock);
                                 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);
@@ -1454,11 +1462,14 @@ static void binder_transaction(struct binder_proc *proc,
                         }
                         target_node = ref->node;
                 } 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);
                                 goto err_no_context_mgr_node;
                         }
+                        mutex_unlock(&context->context_mgr_node_lock);
                 }
                 e->to_node = target_node->debug_id;
                 target_proc = target_node->proc;
@@ -1824,22 +1835,31 @@ static int binder_thread_write(struct binder_proc *proc,
                 case BC_RELEASE:
                 case BC_DECREFS: {
                         uint32_t target;
-                        struct binder_ref *ref;
+                        struct binder_ref *ref = NULL;
                         const char *debug_string;
 
                         if (get_user(target, (uint32_t __user *)ptr))
                                 return -EFAULT;
+
                         ptr += sizeof(uint32_t);
-                        if (target == 0 && context->binder_context_mgr_node &&
+                        if (target == 0 &&
                             (cmd == BC_INCREFS || cmd == BC_ACQUIRE)) {
-                                ref = binder_get_ref_for_node(proc,
-                                        context->binder_context_mgr_node);
-                                if (ref->desc != target) {
-                                        binder_user_error("%d:%d tried to acquire reference to desc 0, got %d instead\n",
-                                                proc->pid, thread->pid,
-                                                ref->desc);
+                                struct binder_node *ctx_mgr_node;
+
+                                mutex_lock(&context->context_mgr_node_lock);
+                                ctx_mgr_node = context->binder_context_mgr_node;
+                                if (ctx_mgr_node) {
+                                        ref = binder_get_ref_for_node(proc,
+                                                        ctx_mgr_node);
+                                        if (ref && ref->desc != target) {
+                                                binder_user_error("%d:%d tried to acquire reference to desc 0, got %d instead\n",
+                                                        proc->pid, thread->pid,
+                                                        ref->desc);
+                                        }
                                 }
-                        } else
+                                mutex_unlock(&context->context_mgr_node_lock);
+                        }
+                        if (ref == NULL)
                                 ref = binder_get_ref(proc, target,
                                                      cmd == BC_ACQUIRE ||
                                                      cmd == BC_RELEASE);
@@ -2753,9 +2773,10 @@ static int binder_ioctl_set_ctx_mgr(struct file *filp)
         int ret = 0;
         struct binder_proc *proc = filp->private_data;
         struct binder_context *context = proc->context;
-
+        struct binder_node *new_node;
         kuid_t curr_euid = current_euid();
 
+        mutex_lock(&context->context_mgr_node_lock);
         if (context->binder_context_mgr_node) {
                 pr_err("BINDER_SET_CONTEXT_MGR already set\n");
                 ret = -EBUSY;
@@ -2776,16 +2797,18 @@ static int binder_ioctl_set_ctx_mgr(struct file *filp)
         } else {
                 context->binder_context_mgr_uid = curr_euid;
         }
-        context->binder_context_mgr_node = binder_new_node(proc, 0, 0);
-        if (!context->binder_context_mgr_node) {
+        new_node = binder_new_node(proc, 0, 0);
+        if (!new_node) {
                 ret = -ENOMEM;
                 goto out;
         }
-        context->binder_context_mgr_node->local_weak_refs++;
-        context->binder_context_mgr_node->local_strong_refs++;
-        context->binder_context_mgr_node->has_strong_ref = 1;
-        context->binder_context_mgr_node->has_weak_ref = 1;
+        new_node->local_weak_refs++;
+        new_node->local_strong_refs++;
+        new_node->has_strong_ref = 1;
+        new_node->has_weak_ref = 1;
+        context->binder_context_mgr_node = new_node;
 out:
+        mutex_unlock(&context->context_mgr_node_lock);
         return ret;
 }
 
@@ -2965,13 +2988,16 @@ static int binder_open(struct inode *nodp, struct file *filp)
         binder_lock(__func__);
 
         binder_stats_created(BINDER_STAT_PROC);
-        hlist_add_head(&proc->proc_node, &binder_procs);
         proc->pid = current->group_leader->pid;
         INIT_LIST_HEAD(&proc->delivered_death);
         filp->private_data = proc;
 
         binder_unlock(__func__);
 
+        mutex_lock(&binder_procs_lock);
+        hlist_add_head(&proc->proc_node, &binder_procs);
+        mutex_unlock(&binder_procs_lock);
+
         if (binder_debugfs_dir_entry_proc) {
                 char strbuf[11];
 
@@ -3050,7 +3076,10 @@ static int binder_node_release(struct binder_node *node, int refs)
         node->proc = NULL;
         node->local_strong_refs = 0;
         node->local_weak_refs = 0;
+
+        spin_lock(&binder_dead_nodes_lock);
         hlist_add_head(&node->dead_node, &binder_dead_nodes);
+        spin_unlock(&binder_dead_nodes_lock);
 
         hlist_for_each_entry(ref, &node->refs, node_entry) {
                 refs++;
@@ -3084,8 +3113,11 @@ static void binder_deferred_release(struct binder_proc *proc)
 
         BUG_ON(proc->files);
 
+        mutex_lock(&binder_procs_lock);
         hlist_del(&proc->proc_node);
+        mutex_unlock(&binder_procs_lock);
 
+        mutex_lock(&context->context_mgr_node_lock);
         if (context->binder_context_mgr_node &&
             context->binder_context_mgr_node->proc == proc) {
                 binder_debug(BINDER_DEBUG_DEAD_BINDER,
@@ -3093,6 +3125,7 @@ static void binder_deferred_release(struct binder_proc *proc)
                              __func__, proc->pid);
                 context->binder_context_mgr_node = NULL;
         }
+        mutex_unlock(&context->context_mgr_node_lock);
 
         threads = 0;
         active_transactions = 0;
@@ -3509,13 +3542,17 @@ static int binder_state_show(struct seq_file *m, void *unused)
 
         seq_puts(m, "binder state:\n");
 
+        spin_lock(&binder_dead_nodes_lock);
         if (!hlist_empty(&binder_dead_nodes))
                 seq_puts(m, "dead nodes:\n");
         hlist_for_each_entry(node, &binder_dead_nodes, dead_node)
                 print_binder_node(m, node);
+        spin_unlock(&binder_dead_nodes_lock);
 
+        mutex_lock(&binder_procs_lock);
         hlist_for_each_entry(proc, &binder_procs, proc_node)
                 print_binder_proc(m, proc, 1);
+        mutex_unlock(&binder_procs_lock);
         binder_unlock(__func__);
         return 0;
 }
@@ -3530,8 +3567,10 @@ static int binder_stats_show(struct seq_file *m, void *unused)
 
         print_binder_stats(m, "", &binder_stats);
 
+        mutex_lock(&binder_procs_lock);
         hlist_for_each_entry(proc, &binder_procs, proc_node)
                 print_binder_proc_stats(m, proc);
+        mutex_unlock(&binder_procs_lock);
         binder_unlock(__func__);
         return 0;
 }
@@ -3543,8 +3582,10 @@ static int binder_transactions_show(struct seq_file *m, void *unused)
         binder_lock(__func__);
 
         seq_puts(m, "binder transactions:\n");
+        mutex_lock(&binder_procs_lock);
         hlist_for_each_entry(proc, &binder_procs, proc_node)
                 print_binder_proc(m, proc, 0);
+        mutex_unlock(&binder_procs_lock);
         binder_unlock(__func__);
         return 0;
 }
@@ -3556,12 +3597,15 @@ static int binder_proc_show(struct seq_file *m, void *unused)
 
         binder_lock(__func__);
 
+        mutex_lock(&binder_procs_lock);
         hlist_for_each_entry(itr, &binder_procs, proc_node) {
                 if (itr->pid == pid) {
                         seq_puts(m, "binder proc state:\n");
                         print_binder_proc(m, itr, 1);
                 }
         }
+        mutex_unlock(&binder_procs_lock);
+
         binder_unlock(__func__);
         return 0;
 }
@@ -3622,6 +3666,7 @@ static int __init init_binder_device(const char *name)
 
         binder_device->context.binder_context_mgr_uid = INVALID_UID;
         binder_device->context.name = name;
+        mutex_init(&binder_device->context.context_mgr_node_lock);
 
         ret = misc_register(&binder_device->miscdev);
         if (ret < 0) {