Re: [PATCH V4] binder: ipc namespace support for android binder

From: Todd Kjos
Date: Mon Nov 12 2018 - 11:45:25 EST


+christian@xxxxxxxxxx +Martijn Coenen

Christian,

Does this patch work for your container use-cases? If not, please
comment on this thread. Let's discuss at LPC this week.

-Todd

On Mon, Nov 12, 2018 at 1:38 AM chouryzhou(åå) <chouryzhou@xxxxxxxxxxx> wrote:
>
> Currently android's 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 multiple instances of 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. For debugfs, binder_proc
> is namespace-aware, but not for binder dead nodes, binder_stats and
> binder_transaction_log_entry (we added ipc inum to trace it).
>
> Signed-off-by: chouryzhou <chouryzhou@xxxxxxxxxxx>
> Reviewed-by: Davidlohr Bueso <dave@xxxxxxxxxxxx>
> ---
> drivers/android/binder.c | 133 ++++++++++++++++++++++++++++++++----------
> include/linux/ipc_namespace.h | 15 +++++
> ipc/namespace.c | 10 +++-
> 3 files changed, 125 insertions(+), 33 deletions(-)
>
> diff --git a/drivers/android/binder.c b/drivers/android/binder.c
> index cb30a524d16d..453265505b04 100644
> --- a/drivers/android/binder.c
> +++ b/drivers/android/binder.c
> @@ -67,6 +67,8 @@
> #include <linux/sched/mm.h>
> #include <linux/seq_file.h>
> #include <linux/uaccess.h>
> +#include <linux/proc_ns.h>
> +#include <linux/ipc_namespace.h>
> #include <linux/pid_namespace.h>
> #include <linux/security.h>
> #include <linux/spinlock.h>
> @@ -80,13 +82,21 @@
> #include "binder_alloc.h"
> #include "binder_trace.h"
>
> +
> +#ifndef CONFIG_IPC_NS
> +static struct ipc_namespace binder_ipc_ns = {
> + .ns.inum = PROC_IPC_INIT_INO,
> +};
> +
> +#define ipcns (&binder_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);
>
> @@ -233,6 +243,7 @@ struct binder_transaction_log_entry {
> uint32_t return_error;
> uint32_t return_error_param;
> const char *context_name;
> + unsigned int ipc_inum;
> };
> struct binder_transaction_log {
> atomic_t cur;
> @@ -263,19 +274,66 @@ 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;
> + int device;
> const char *name;
> };
>
> 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);
> + 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);
> + 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->name = device->miscdev.name;
> + 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
> @@ -2728,6 +2786,7 @@ static void binder_transaction(struct binder_proc *proc,
> e->data_size = tr->data_size;
> e->offsets_size = tr->offsets_size;
> e->context_name = proc->context->name;
> + e->ipc_inum = ipcns->ns.inum;
>
> if (reply) {
> binder_inner_proc_lock(proc);
> @@ -4922,6 +4981,7 @@ 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 +4997,15 @@ 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;
> + hlist_for_each_entry(context, &ipcns->binder_contexts, hlist) {
> + if (context->device == binder_dev->miscdev.minor) {
> + proc->context = context;
> + break;
> + }
> + }
> + if (!proc->context)
> + return -ENOENT;
> +
> binder_alloc_init(&proc->alloc);
>
> binder_stats_created(BINDER_STAT_PROC);
> @@ -4946,9 +5014,9 @@ 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 +5150,9 @@ 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 &&
> @@ -5623,10 +5691,10 @@ 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 +5707,10 @@ 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 +5720,10 @@ 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 +5733,14 @@ 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;
> }
> @@ -5687,12 +5755,12 @@ 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 ipc %d context %s 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->to_node, e->target_handle, e->data_size, e->offsets_size,
> - e->return_error, e->return_error_param,
> + e->from_thread, e->to_proc, e->to_thread, e->ipc_inum,
> + e->context_name, e->to_node, e->target_handle, e->data_size,
> + e->offsets_size, e->return_error, e->return_error_param,
> e->return_error_line);
> /*
> * read-barrier to guarantee read of debug_id_done after
> @@ -5753,10 +5821,6 @@ 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);
> @@ -5831,9 +5895,16 @@ static int __init binder_init(void)
> if (ret)
> goto err_init_binder_device_failed;
> }
> +#ifdef CONFIG_IPC_NS
> + ret = binder_init_ns(&init_ipc_ns);
> +#else
> + ret = binder_init_ns(&binder_ipc_ns);
> +#endif
> + 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..d7f850a2ded8 100644
> --- a/include/linux/ipc_namespace.h
> +++ b/include/linux/ipc_namespace.h
> @@ -63,6 +63,13 @@ struct ipc_namespace {
> unsigned int mq_msg_default;
> unsigned int mq_msgsize_default;
>
> +#ifdef CONFIG_ANDROID_BINDER_IPC
> + /* next fields are for binder */
> + struct mutex binder_procs_lock;
> + struct hlist_head binder_procs;
> + struct hlist_head binder_contexts;
> +#endif
> +
> /* user_ns which owns the ipc ns */
> struct user_namespace *user_ns;
> struct ucounts *ucounts;
> @@ -118,6 +125,14 @@ 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..68c6e983b002 100644
> --- a/ipc/namespace.c
> +++ b/ipc/namespace.c
> @@ -57,7 +57,10 @@ static struct ipc_namespace *create_ipc_ns(struct user_namespace *user_ns,
>
> err = mq_init_ns(ns);
> if (err)
> - goto fail_put;
> + goto fail_init_mq;
> + err = binder_init_ns(ns);
> + if (err)
> + goto fail_init_binder;
>
> sem_init_ns(ns);
> msg_init_ns(ns);
> @@ -65,7 +68,9 @@ static struct ipc_namespace *create_ipc_ns(struct user_namespace *user_ns,
>
> return ns;
>
> -fail_put:
> +fail_init_binder:
> + mq_put_mnt(ns);
> +fail_init_mq:
> put_user_ns(ns->user_ns);
> ns_free_inum(&ns->ns);
> fail_free:
> @@ -120,6 +125,7 @@ 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);
> --
> 2.11.0