From b492213c96ded86e7800b320706ad15bd31c7c1b Mon Sep 17 00:00:00 2001 From: Christian Brauner Date: Wed, 16 Jan 2019 23:13:25 +0100 Subject: [PATCH 1/4] binder: turn into module The Android binder driver needs to become a module for the sake of shipping Anbox. To do this we need to export the following functions since binder is currently still using them: - security_binder_set_context_mgr() - security_binder_transaction() - security_binder_transfer_binder() - security_binder_transfer_file() - can_nice() - __close_fd_get_file() - mmput_async() - task_work_add() - map_kernel_range_noflush() - get_vm_area() - zap_page_range_single() - put_ipc_ns() - get_ipc_ns_exported() - show_init_ipc_ns() Signed-off-by: Christian Brauner [ saf: fix additional reference to init_ipc_ns from 5.0-rc6 ] Signed-off-by: Seth Forshee [ arighi: fix EXPORT_SYMBOL vs EXPORT_SYMBOL_GPL change from 6.0-rc5 ] [ arighi: zap_page_range() has been dropped, export zap_page_range_single() in 6.3 ] Signed-off-by: Andrea Righi Signed-off-by: Alexandre Frade --- a/drivers/android/Kconfig +++ b/drivers/android/Kconfig @@ -14,8 +14,8 @@ config ANDROID_BINDER_IPC between said processes. config ANDROID_BINDERFS - bool "Android Binderfs filesystem" - depends on ANDROID_BINDER_IPC + tristate "Android Binderfs filesystem" + depends on (ANDROID_BINDER_IPC=y) || (ANDROID_BINDER_IPC=m && m) default n help Binderfs is a pseudo-filesystem for the Android Binder IPC driver --- a/drivers/android/binder.c +++ b/drivers/android/binder.c @@ -7027,9 +7027,20 @@ err_alloc_device_names_failed: return ret; } -device_initcall(binder_init); +module_init(binder_init); +/* + * binder will have no exit function since binderfs instances can be mounted + * multiple times and also in user namespaces finding and destroying them all + * is not feasible without introducing insane locking. Just ignoring existing + * instances on module unload also wouldn't work since we would loose track of + * what major numer was dynamically allocated and also what minor numbers are + * already given out. So this would get us into all kinds of issues with device + * number reuse. So simply don't allow unloading unless we are forced to do so. + */ + +MODULE_AUTHOR("Google, Inc."); +MODULE_DESCRIPTION("Driver for Android binder device"); +MODULE_LICENSE("GPL v2"); #define CREATE_TRACE_POINTS #include "binder_trace.h" - -MODULE_LICENSE("GPL v2"); --- a/drivers/android/binder_alloc.h +++ b/drivers/android/binder_alloc.h @@ -6,6 +6,7 @@ #ifndef _LINUX_BINDER_ALLOC_H #define _LINUX_BINDER_ALLOC_H +#include #include #include #include @@ -111,7 +112,7 @@ struct binder_alloc { bool oneway_spam_detected; }; -#ifdef CONFIG_ANDROID_BINDER_IPC_SELFTEST +#if IS_ENABLED(CONFIG_ANDROID_BINDER_IPC_SELFTEST) void binder_selftest_alloc(struct binder_alloc *alloc); #else static inline void binder_selftest_alloc(struct binder_alloc *alloc) {} --- a/drivers/android/binder_internal.h +++ b/drivers/android/binder_internal.h @@ -5,6 +5,7 @@ #include #include +#include #include #include #include @@ -78,7 +79,7 @@ extern const struct file_operations bind extern char *binder_devices_param; -#ifdef CONFIG_ANDROID_BINDERFS +#if IS_ENABLED(CONFIG_ANDROID_BINDERFS) extern bool is_binderfs_device(const struct inode *inode); extern struct dentry *binderfs_create_file(struct dentry *dir, const char *name, const struct file_operations *fops, @@ -99,7 +100,7 @@ static inline struct dentry *binderfs_cr static inline void binderfs_remove_file(struct dentry *dentry) {} #endif -#ifdef CONFIG_ANDROID_BINDERFS +#if IS_ENABLED(CONFIG_ANDROID_BINDERFS) extern int __init init_binderfs(void); #else static inline int __init init_binderfs(void) --- a/drivers/android/binderfs.c +++ b/drivers/android/binderfs.c @@ -122,7 +122,7 @@ static int binderfs_binder_device_create struct super_block *sb = ref_inode->i_sb; struct binderfs_info *info = sb->s_fs_info; #if defined(CONFIG_IPC_NS) - bool use_reserve = (info->ipc_ns == &init_ipc_ns); + bool use_reserve = (info->ipc_ns == show_init_ipc_ns()); #else bool use_reserve = true; #endif @@ -399,7 +399,7 @@ static int binderfs_binder_ctl_create(st struct dentry *root = sb->s_root; struct binderfs_info *info = sb->s_fs_info; #if defined(CONFIG_IPC_NS) - bool use_reserve = (info->ipc_ns == &init_ipc_ns); + bool use_reserve = (info->ipc_ns == show_init_ipc_ns()); #else bool use_reserve = true; #endif @@ -691,7 +691,7 @@ static int binderfs_fill_super(struct su return -ENOMEM; info = sb->s_fs_info; - info->ipc_ns = get_ipc_ns(current->nsproxy->ipc_ns); + info->ipc_ns = get_ipc_ns_exported(current->nsproxy->ipc_ns); info->root_gid = make_kgid(sb->s_user_ns, 0); if (!gid_valid(info->root_gid)) --- a/include/linux/ipc_namespace.h +++ b/include/linux/ipc_namespace.h @@ -128,6 +128,9 @@ extern int mq_init_ns(struct ipc_namespa static inline int mq_init_ns(struct ipc_namespace *ns) { return 0; } #endif +extern struct ipc_namespace *get_ipc_ns_exported(struct ipc_namespace *ns); +extern struct ipc_namespace *show_init_ipc_ns(void); + #if defined(CONFIG_IPC_NS) extern struct ipc_namespace *copy_ipcs(unsigned long flags, struct user_namespace *user_ns, struct ipc_namespace *ns); --- a/ipc/namespace.c +++ b/ipc/namespace.c @@ -209,6 +209,22 @@ void put_ipc_ns(struct ipc_namespace *ns } EXPORT_SYMBOL_GPL(put_ipc_ns); +struct ipc_namespace *get_ipc_ns_exported(struct ipc_namespace *ns) +{ + return get_ipc_ns(ns); +} +EXPORT_SYMBOL(get_ipc_ns_exported); + +struct ipc_namespace *show_init_ipc_ns(void) +{ +#if defined(CONFIG_IPC_NS) + return &init_ipc_ns; +#else + return NULL; +#endif +} +EXPORT_SYMBOL(show_init_ipc_ns); + static inline struct ipc_namespace *to_ipc_ns(struct ns_common *ns) { return container_of(ns, struct ipc_namespace, ns); --- a/mm/vmalloc.c +++ b/mm/vmalloc.c @@ -3176,6 +3176,7 @@ struct vm_struct *get_vm_area(unsigned l NUMA_NO_NODE, GFP_KERNEL, __builtin_return_address(0)); } +EXPORT_SYMBOL(get_vm_area); struct vm_struct *get_vm_area_caller(unsigned long size, unsigned long flags, const void *caller)