[PATCH V2] binder: ipc namespace support for android binder

[chouryzhou(åå)]

  We are working for running android in container, but we found that binder is
not isolated by ipc namespace. Since binder is a form of IPC and therefore should
be tied to ipc namespace. With this patch, we can run more than one android
container on one host.
  This patch move "binder_procs" and "binder_context" into ipc_namespace,
driver will find the context from it when opening. Althought statistics in debugfs
remain global.

Signed-off-by: chouryzhou <chouryzhou@xxxxxxxxxxx>
---
 drivers/android/binder.c      | 134 +++++++++++++++++++++++++---------
 include/linux/ipc_namespace.h |  14 ++++
 ipc/namespace.c               |   4 +
 3 files changed, 118 insertions(+), 34 deletions(-)

diff --git a/drivers/android/binder.c b/drivers/android/binder.c
index cb30a524d16d..98e815e3472d 100644
--- a/drivers/android/binder.c
+++ b/drivers/android/binder.c
@@ -68,6 +68,7 @@
 #include <linux/seq_file.h>
 #include <linux/uaccess.h>
 #include <linux/pid_namespace.h>
+#include <linux/ipc_namespace.h>
 #include <linux/security.h>
 #include <linux/spinlock.h>
 #include <linux/ratelimit.h>
@@ -80,13 +81,20 @@
 #include "binder_alloc.h"
 #include "binder_trace.h"
 
+
+// If init_ipc_ns is not defined elsewhere,
+// we make a fake one here to put our variable.
+#if !defined(CONFIG_SYSVIPC) &&  !defined(CONFIG_POSIX_MQUEUE)
+struct ipc_namespace init_ipc_ns;
+#define ipcns  (&init_ipc_ns)
+#else
+#define ipcns  (current->nsproxy->ipc_ns)
+#endif
+
 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);
 
@@ -232,7 +240,7 @@ struct binder_transaction_log_entry {
        int return_error_line;
        uint32_t return_error;
        uint32_t return_error_param;
-       const char *context_name;
+       int context_device;
 };
 struct binder_transaction_log {
        atomic_t cur;
@@ -263,19 +271,66 @@ static struct binder_transaction_log_entry *binder_transaction_log_add(
 }
 
 struct binder_context {
+       struct hlist_node hlist;
        struct binder_node *binder_context_mgr_node;
        struct mutex context_mgr_node_lock;
 
        kuid_t binder_context_mgr_uid;
-       const char *name;
+       int    device;
 };
 
 struct binder_device {
        struct hlist_node hlist;
        struct miscdevice miscdev;
-       struct binder_context context;
 };
 
+void binder_exit_ns(struct ipc_namespace *ns)
+{
+       struct binder_context *context;
+       struct hlist_node *tmp;
+
+       mutex_destroy(&ns->binder_procs_lock);
+       mutex_destroy(&ns->binder_contexts_lock);
+       hlist_for_each_entry_safe(context, tmp, &ns->binder_contexts, hlist) {
+               mutex_destroy(&context->context_mgr_node_lock);
+               hlist_del(&context->hlist);
+               kfree(context);
+       }
+}
+
+int binder_init_ns(struct ipc_namespace *ns)
+{
+       int ret;
+       struct binder_device *device;
+
+       mutex_init(&ns->binder_procs_lock);
+       INIT_HLIST_HEAD(&ns->binder_procs);
+       mutex_init(&ns->binder_contexts_lock);
+       INIT_HLIST_HEAD(&ns->binder_contexts);
+
+       hlist_for_each_entry(device, &binder_devices, hlist) {
+               struct binder_context *context;
+
+               context = kzalloc(sizeof(*context), GFP_KERNEL);
+               if (!context) {
+                       ret = -ENOMEM;
+                       goto err;
+               }
+
+               context->device = device->miscdev.minor;
+               context->binder_context_mgr_uid = INVALID_UID;
+               mutex_init(&context->context_mgr_node_lock);
+
+               hlist_add_head(&context->hlist, &ns->binder_contexts);
+       }
+
+       return 0;
+err:
+       binder_exit_ns(ns);
+       return ret;
+}
+
+
 /**
  * struct binder_work - work enqueued on a worklist
  * @entry:             node enqueued on list
@@ -2727,7 +2782,7 @@ static void binder_transaction(struct binder_proc *proc,
        e->target_handle = tr->target.handle;
        e->data_size = tr->data_size;
        e->offsets_size = tr->offsets_size;
-       e->context_name = proc->context->name;
+       e->context_device = proc->context->device;
 
        if (reply) {
                binder_inner_proc_lock(proc);
@@ -4922,6 +4977,7 @@ static int binder_open(struct inode *nodp, struct file *filp)
 {
        struct binder_proc *proc;
        struct binder_device *binder_dev;
+       struct binder_context *context;
 
        binder_debug(BINDER_DEBUG_OPEN_CLOSE, "%s: %d:%d\n", __func__,
                     current->group_leader->pid, current->pid);
@@ -4937,7 +4993,17 @@ static int binder_open(struct inode *nodp, struct file *filp)
        proc->default_priority = task_nice(current);
        binder_dev = container_of(filp->private_data, struct binder_device,
                                  miscdev);
-       proc->context = &binder_dev->context;
+       mutex_lock(&ipcns->binder_contexts_lock);
+       hlist_for_each_entry(context, &ipcns->binder_contexts, hlist) {
+               if (context->device == binder_dev->miscdev.minor) {
+                       proc->context = context;
+                       break;
+               }
+       }
+       mutex_unlock(&ipcns->binder_contexts_lock);
+       if (!proc->context)
+               return -ENOENT;
+
        binder_alloc_init(&proc->alloc);
 
        binder_stats_created(BINDER_STAT_PROC);
@@ -4946,9 +5012,9 @@ static int binder_open(struct inode *nodp, struct file *filp)
        INIT_LIST_HEAD(&proc->waiting_threads);
        filp->private_data = proc;
 
-       mutex_lock(&binder_procs_lock);
-       hlist_add_head(&proc->proc_node, &binder_procs);
-       mutex_unlock(&binder_procs_lock);
+       mutex_lock(&ipcns->binder_procs_lock);
+       hlist_add_head(&proc->proc_node, &ipcns->binder_procs);
+       mutex_unlock(&ipcns->binder_procs_lock);
 
        if (binder_debugfs_dir_entry_proc) {
                char strbuf[11];
@@ -5082,9 +5148,9 @@ static void binder_deferred_release(struct binder_proc *proc)
        struct rb_node *n;
        int threads, nodes, incoming_refs, outgoing_refs, active_transactions;
 
-       mutex_lock(&binder_procs_lock);
+       mutex_lock(&ipcns->binder_procs_lock);
        hlist_del(&proc->proc_node);
-       mutex_unlock(&binder_procs_lock);
+       mutex_unlock(&ipcns->binder_procs_lock);
 
        mutex_lock(&context->context_mgr_node_lock);
        if (context->binder_context_mgr_node &&
@@ -5377,7 +5443,7 @@ static void print_binder_proc(struct seq_file *m,
        struct binder_node *last_node = NULL;
 
        seq_printf(m, "proc %d\n", proc->pid);
-       seq_printf(m, "context %s\n", proc->context->name);
+       seq_printf(m, "context %d\n", proc->context->device);
        header_pos = m->count;
 
        binder_inner_proc_lock(proc);
@@ -5538,7 +5604,7 @@ static void print_binder_proc_stats(struct seq_file *m,
                binder_alloc_get_free_async_space(&proc->alloc);
 
        seq_printf(m, "proc %d\n", proc->pid);
-       seq_printf(m, "context %s\n", proc->context->name);
+       seq_printf(m, "context %d\n", proc->context->device);
        count = 0;
        ready_threads = 0;
        binder_inner_proc_lock(proc);
@@ -5623,10 +5689,10 @@ static int binder_state_show(struct seq_file *m, void *unused)
        if (last_node)
                binder_put_node(last_node);
 
-       mutex_lock(&binder_procs_lock);
-       hlist_for_each_entry(proc, &binder_procs, proc_node)
+       mutex_lock(&ipcns->binder_procs_lock);
+       hlist_for_each_entry(proc, &ipcns->binder_procs, proc_node)
                print_binder_proc(m, proc, 1);
-       mutex_unlock(&binder_procs_lock);
+       mutex_unlock(&ipcns->binder_procs_lock);
 
        return 0;
 }
@@ -5639,10 +5705,10 @@ 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)
+       mutex_lock(&ipcns->binder_procs_lock);
+       hlist_for_each_entry(proc, &ipcns->binder_procs, proc_node)
                print_binder_proc_stats(m, proc);
-       mutex_unlock(&binder_procs_lock);
+       mutex_unlock(&ipcns->binder_procs_lock);
 
        return 0;
 }
@@ -5652,10 +5718,10 @@ static int binder_transactions_show(struct seq_file *m, void *unused)
        struct binder_proc *proc;
 
        seq_puts(m, "binder transactions:\n");
-       mutex_lock(&binder_procs_lock);
-       hlist_for_each_entry(proc, &binder_procs, proc_node)
+       mutex_lock(&ipcns->binder_procs_lock);
+       hlist_for_each_entry(proc, &ipcns->binder_procs, proc_node)
                print_binder_proc(m, proc, 0);
-       mutex_unlock(&binder_procs_lock);
+       mutex_unlock(&ipcns->binder_procs_lock);
 
        return 0;
 }
@@ -5665,14 +5731,14 @@ static int binder_proc_show(struct seq_file *m, void *unused)
        struct binder_proc *itr;
        int pid = (unsigned long)m->private;
 
-       mutex_lock(&binder_procs_lock);
-       hlist_for_each_entry(itr, &binder_procs, proc_node) {
+       mutex_lock(&ipcns->binder_procs_lock);
+       hlist_for_each_entry(itr, &ipcns->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);
+       mutex_unlock(&ipcns->binder_procs_lock);
 
        return 0;
 }
@@ -5687,10 +5753,10 @@ static void print_binder_transaction_log_entry(struct seq_file *m,
         */
        smp_rmb();
        seq_printf(m,
-                  "%d: %s from %d:%d to %d:%d context %s node %d handle %d size %d:%d ret %d/%d l=%d",
+                  "%d: %s from %d:%d to %d:%d context %d node %d handle %d size %d:%d ret %d/%d l=%d",
                   e->debug_id, (e->call_type == 2) ? "reply" :
                   ((e->call_type == 1) ? "async" : "call "), e->from_proc,
-                  e->from_thread, e->to_proc, e->to_thread, e->context_name,
+                  e->from_thread, e->to_proc, e->to_thread, e->context_device,
                   e->to_node, e->target_handle, e->data_size, e->offsets_size,
                   e->return_error, e->return_error_param,
                   e->return_error_line);
@@ -5753,10 +5819,6 @@ static int __init init_binder_device(const char *name)
        binder_device->miscdev.minor = MISC_DYNAMIC_MINOR;
        binder_device->miscdev.name = 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) {
                kfree(binder_device);
@@ -5832,8 +5894,12 @@ static int __init binder_init(void)
                        goto err_init_binder_device_failed;
        }
 
-       return ret;
+       ret = binder_init_ns(&init_ipc_ns);
+       if (ret)
+               goto err_init_namespace_failed;
 
+       return ret;
+err_init_namespace_failed:
 err_init_binder_device_failed:
        hlist_for_each_entry_safe(device, tmp, &binder_devices, hlist) {
                misc_deregister(&device->miscdev);
diff --git a/include/linux/ipc_namespace.h b/include/linux/ipc_namespace.h
index 6ab8c1bada3f..a5a9f9a8f945 100644
--- a/include/linux/ipc_namespace.h
+++ b/include/linux/ipc_namespace.h
@@ -63,6 +63,12 @@ struct ipc_namespace {
        unsigned int    mq_msg_default;
        unsigned int    mq_msgsize_default;
 
+       /* next fields are for binder */
+       struct mutex      binder_procs_lock;
+       struct hlist_head binder_procs;
+       struct mutex      binder_contexts_lock;
+       struct hlist_head binder_contexts;
+
        /* user_ns which owns the ipc ns */
        struct user_namespace *user_ns;
        struct ucounts *ucounts;
@@ -118,6 +124,14 @@ extern int mq_init_ns(struct ipc_namespace *ns);
 static inline int mq_init_ns(struct ipc_namespace *ns) { return 0; }
 #endif
 
+#ifdef CONFIG_ANDROID_BINDER_IPC
+extern int binder_init_ns(struct ipc_namespace *ns);
+extern void binder_exit_ns(struct ipc_namespace *ns);
+#else
+static inline int binder_init_ns(struct ipc_namespace *ns) { return 0; }
+static inline void binder_exit_ns(struct ipc_namespace *ns) { }
+#endif
+
 #if defined(CONFIG_IPC_NS)
 extern struct ipc_namespace *copy_ipcs(unsigned long flags,
        struct user_namespace *user_ns, struct ipc_namespace *ns);
diff --git a/ipc/namespace.c b/ipc/namespace.c
index 21607791d62c..8b56a6abff59 100644
--- a/ipc/namespace.c
+++ b/ipc/namespace.c
@@ -56,6 +56,9 @@ static struct ipc_namespace *create_ipc_ns(struct user_namespace *user_ns,
        ns->ucounts = ucounts;
 
        err = mq_init_ns(ns);
+       if (err)
+               goto fail_put;
+       err = binder_init_ns(ns);
        if (err)
                goto fail_put;
 
@@ -120,6 +123,7 @@ static void free_ipc_ns(struct ipc_namespace *ns)
        sem_exit_ns(ns);
        msg_exit_ns(ns);
        shm_exit_ns(ns);
+       binder_exit_ns(ns);
 
        dec_ipc_namespaces(ns->ucounts);
        put_user_ns(ns->user_ns);
-- 
2.19.1