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1777 lines
43 KiB
1777 lines
43 KiB
// SPDX-License-Identifier: GPL-2.0 |
|
/* |
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* linux/ipc/shm.c |
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* Copyright (C) 1992, 1993 Krishna Balasubramanian |
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* Many improvements/fixes by Bruno Haible. |
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* Replaced `struct shm_desc' by `struct vm_area_struct', July 1994. |
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* Fixed the shm swap deallocation (shm_unuse()), August 1998 Andrea Arcangeli. |
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* |
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* /proc/sysvipc/shm support (c) 1999 Dragos Acostachioaie <[email protected]> |
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* BIGMEM support, Andrea Arcangeli <[email protected]> |
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* SMP thread shm, Jean-Luc Boyard <[email protected]> |
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* HIGHMEM support, Ingo Molnar <[email protected]> |
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* Make shmmax, shmall, shmmni sysctl'able, Christoph Rohland <[email protected]> |
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* Shared /dev/zero support, Kanoj Sarcar <[email protected]> |
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* Move the mm functionality over to mm/shmem.c, Christoph Rohland <[email protected]> |
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* |
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* support for audit of ipc object properties and permission changes |
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* Dustin Kirkland <[email protected]> |
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* |
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* namespaces support |
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* OpenVZ, SWsoft Inc. |
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* Pavel Emelianov <[email protected]> |
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* |
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* Better ipc lock (kern_ipc_perm.lock) handling |
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* Davidlohr Bueso <[email protected]>, June 2013. |
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*/ |
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|
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#include <linux/slab.h> |
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#include <linux/mm.h> |
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#include <linux/hugetlb.h> |
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#include <linux/shm.h> |
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#include <linux/init.h> |
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#include <linux/file.h> |
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#include <linux/mman.h> |
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#include <linux/shmem_fs.h> |
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#include <linux/security.h> |
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#include <linux/syscalls.h> |
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#include <linux/audit.h> |
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#include <linux/capability.h> |
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#include <linux/ptrace.h> |
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#include <linux/seq_file.h> |
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#include <linux/rwsem.h> |
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#include <linux/nsproxy.h> |
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#include <linux/mount.h> |
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#include <linux/ipc_namespace.h> |
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#include <linux/rhashtable.h> |
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|
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#include <linux/uaccess.h> |
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|
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#include "util.h" |
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|
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struct shmid_kernel /* private to the kernel */ |
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{ |
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struct kern_ipc_perm shm_perm; |
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struct file *shm_file; |
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unsigned long shm_nattch; |
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unsigned long shm_segsz; |
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time64_t shm_atim; |
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time64_t shm_dtim; |
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time64_t shm_ctim; |
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struct pid *shm_cprid; |
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struct pid *shm_lprid; |
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struct ucounts *mlock_ucounts; |
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|
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/* The task created the shm object. NULL if the task is dead. */ |
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struct task_struct *shm_creator; |
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struct list_head shm_clist; /* list by creator */ |
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} __randomize_layout; |
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|
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/* shm_mode upper byte flags */ |
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#define SHM_DEST 01000 /* segment will be destroyed on last detach */ |
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#define SHM_LOCKED 02000 /* segment will not be swapped */ |
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|
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struct shm_file_data { |
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int id; |
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struct ipc_namespace *ns; |
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struct file *file; |
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const struct vm_operations_struct *vm_ops; |
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}; |
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|
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#define shm_file_data(file) (*((struct shm_file_data **)&(file)->private_data)) |
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|
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static const struct file_operations shm_file_operations; |
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static const struct vm_operations_struct shm_vm_ops; |
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|
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#define shm_ids(ns) ((ns)->ids[IPC_SHM_IDS]) |
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|
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#define shm_unlock(shp) \ |
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ipc_unlock(&(shp)->shm_perm) |
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|
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static int newseg(struct ipc_namespace *, struct ipc_params *); |
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static void shm_open(struct vm_area_struct *vma); |
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static void shm_close(struct vm_area_struct *vma); |
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static void shm_destroy(struct ipc_namespace *ns, struct shmid_kernel *shp); |
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#ifdef CONFIG_PROC_FS |
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static int sysvipc_shm_proc_show(struct seq_file *s, void *it); |
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#endif |
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|
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void shm_init_ns(struct ipc_namespace *ns) |
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{ |
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ns->shm_ctlmax = SHMMAX; |
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ns->shm_ctlall = SHMALL; |
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ns->shm_ctlmni = SHMMNI; |
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ns->shm_rmid_forced = 0; |
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ns->shm_tot = 0; |
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ipc_init_ids(&shm_ids(ns)); |
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} |
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|
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/* |
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* Called with shm_ids.rwsem (writer) and the shp structure locked. |
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* Only shm_ids.rwsem remains locked on exit. |
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*/ |
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static void do_shm_rmid(struct ipc_namespace *ns, struct kern_ipc_perm *ipcp) |
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{ |
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struct shmid_kernel *shp; |
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|
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shp = container_of(ipcp, struct shmid_kernel, shm_perm); |
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|
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if (shp->shm_nattch) { |
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shp->shm_perm.mode |= SHM_DEST; |
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/* Do not find it any more */ |
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ipc_set_key_private(&shm_ids(ns), &shp->shm_perm); |
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shm_unlock(shp); |
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} else |
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shm_destroy(ns, shp); |
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} |
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|
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#ifdef CONFIG_IPC_NS |
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void shm_exit_ns(struct ipc_namespace *ns) |
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{ |
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free_ipcs(ns, &shm_ids(ns), do_shm_rmid); |
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idr_destroy(&ns->ids[IPC_SHM_IDS].ipcs_idr); |
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rhashtable_destroy(&ns->ids[IPC_SHM_IDS].key_ht); |
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} |
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#endif |
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|
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static int __init ipc_ns_init(void) |
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{ |
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shm_init_ns(&init_ipc_ns); |
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return 0; |
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} |
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|
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pure_initcall(ipc_ns_init); |
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|
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void __init shm_init(void) |
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{ |
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ipc_init_proc_interface("sysvipc/shm", |
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#if BITS_PER_LONG <= 32 |
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" key shmid perms size cpid lpid nattch uid gid cuid cgid atime dtime ctime rss swap\n", |
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#else |
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" key shmid perms size cpid lpid nattch uid gid cuid cgid atime dtime ctime rss swap\n", |
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#endif |
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IPC_SHM_IDS, sysvipc_shm_proc_show); |
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} |
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|
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static inline struct shmid_kernel *shm_obtain_object(struct ipc_namespace *ns, int id) |
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{ |
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struct kern_ipc_perm *ipcp = ipc_obtain_object_idr(&shm_ids(ns), id); |
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|
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if (IS_ERR(ipcp)) |
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return ERR_CAST(ipcp); |
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|
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return container_of(ipcp, struct shmid_kernel, shm_perm); |
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} |
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|
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static inline struct shmid_kernel *shm_obtain_object_check(struct ipc_namespace *ns, int id) |
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{ |
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struct kern_ipc_perm *ipcp = ipc_obtain_object_check(&shm_ids(ns), id); |
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|
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if (IS_ERR(ipcp)) |
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return ERR_CAST(ipcp); |
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|
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return container_of(ipcp, struct shmid_kernel, shm_perm); |
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} |
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|
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/* |
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* shm_lock_(check_) routines are called in the paths where the rwsem |
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* is not necessarily held. |
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*/ |
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static inline struct shmid_kernel *shm_lock(struct ipc_namespace *ns, int id) |
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{ |
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struct kern_ipc_perm *ipcp; |
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|
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rcu_read_lock(); |
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ipcp = ipc_obtain_object_idr(&shm_ids(ns), id); |
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if (IS_ERR(ipcp)) |
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goto err; |
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|
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ipc_lock_object(ipcp); |
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/* |
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* ipc_rmid() may have already freed the ID while ipc_lock_object() |
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* was spinning: here verify that the structure is still valid. |
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* Upon races with RMID, return -EIDRM, thus indicating that |
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* the ID points to a removed identifier. |
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*/ |
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if (ipc_valid_object(ipcp)) { |
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/* return a locked ipc object upon success */ |
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return container_of(ipcp, struct shmid_kernel, shm_perm); |
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} |
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|
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ipc_unlock_object(ipcp); |
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ipcp = ERR_PTR(-EIDRM); |
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err: |
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rcu_read_unlock(); |
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/* |
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* Callers of shm_lock() must validate the status of the returned ipc |
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* object pointer and error out as appropriate. |
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*/ |
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return ERR_CAST(ipcp); |
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} |
|
|
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static inline void shm_lock_by_ptr(struct shmid_kernel *ipcp) |
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{ |
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rcu_read_lock(); |
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ipc_lock_object(&ipcp->shm_perm); |
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} |
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|
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static void shm_rcu_free(struct rcu_head *head) |
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{ |
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struct kern_ipc_perm *ptr = container_of(head, struct kern_ipc_perm, |
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rcu); |
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struct shmid_kernel *shp = container_of(ptr, struct shmid_kernel, |
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shm_perm); |
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security_shm_free(&shp->shm_perm); |
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kfree(shp); |
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} |
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|
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static inline void shm_rmid(struct ipc_namespace *ns, struct shmid_kernel *s) |
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{ |
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list_del(&s->shm_clist); |
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ipc_rmid(&shm_ids(ns), &s->shm_perm); |
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} |
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static int __shm_open(struct vm_area_struct *vma) |
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{ |
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struct file *file = vma->vm_file; |
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struct shm_file_data *sfd = shm_file_data(file); |
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struct shmid_kernel *shp; |
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shp = shm_lock(sfd->ns, sfd->id); |
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if (IS_ERR(shp)) |
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return PTR_ERR(shp); |
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if (shp->shm_file != sfd->file) { |
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/* ID was reused */ |
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shm_unlock(shp); |
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return -EINVAL; |
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} |
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|
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shp->shm_atim = ktime_get_real_seconds(); |
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ipc_update_pid(&shp->shm_lprid, task_tgid(current)); |
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shp->shm_nattch++; |
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shm_unlock(shp); |
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return 0; |
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} |
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/* This is called by fork, once for every shm attach. */ |
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static void shm_open(struct vm_area_struct *vma) |
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{ |
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int err = __shm_open(vma); |
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/* |
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* We raced in the idr lookup or with shm_destroy(). |
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* Either way, the ID is busted. |
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*/ |
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WARN_ON_ONCE(err); |
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} |
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|
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/* |
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* shm_destroy - free the struct shmid_kernel |
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* |
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* @ns: namespace |
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* @shp: struct to free |
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* |
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* It has to be called with shp and shm_ids.rwsem (writer) locked, |
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* but returns with shp unlocked and freed. |
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*/ |
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static void shm_destroy(struct ipc_namespace *ns, struct shmid_kernel *shp) |
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{ |
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struct file *shm_file; |
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shm_file = shp->shm_file; |
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shp->shm_file = NULL; |
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ns->shm_tot -= (shp->shm_segsz + PAGE_SIZE - 1) >> PAGE_SHIFT; |
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shm_rmid(ns, shp); |
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shm_unlock(shp); |
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if (!is_file_hugepages(shm_file)) |
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shmem_lock(shm_file, 0, shp->mlock_ucounts); |
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else if (shp->mlock_ucounts) |
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user_shm_unlock(i_size_read(file_inode(shm_file)), |
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shp->mlock_ucounts); |
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fput(shm_file); |
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ipc_update_pid(&shp->shm_cprid, NULL); |
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ipc_update_pid(&shp->shm_lprid, NULL); |
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ipc_rcu_putref(&shp->shm_perm, shm_rcu_free); |
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} |
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/* |
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* shm_may_destroy - identifies whether shm segment should be destroyed now |
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* |
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* Returns true if and only if there are no active users of the segment and |
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* one of the following is true: |
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* |
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* 1) shmctl(id, IPC_RMID, NULL) was called for this shp |
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* |
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* 2) sysctl kernel.shm_rmid_forced is set to 1. |
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*/ |
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static bool shm_may_destroy(struct ipc_namespace *ns, struct shmid_kernel *shp) |
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{ |
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return (shp->shm_nattch == 0) && |
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(ns->shm_rmid_forced || |
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(shp->shm_perm.mode & SHM_DEST)); |
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} |
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|
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/* |
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* remove the attach descriptor vma. |
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* free memory for segment if it is marked destroyed. |
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* The descriptor has already been removed from the current->mm->mmap list |
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* and will later be kfree()d. |
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*/ |
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static void shm_close(struct vm_area_struct *vma) |
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{ |
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struct file *file = vma->vm_file; |
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struct shm_file_data *sfd = shm_file_data(file); |
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struct shmid_kernel *shp; |
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struct ipc_namespace *ns = sfd->ns; |
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|
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down_write(&shm_ids(ns).rwsem); |
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/* remove from the list of attaches of the shm segment */ |
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shp = shm_lock(ns, sfd->id); |
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|
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/* |
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* We raced in the idr lookup or with shm_destroy(). |
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* Either way, the ID is busted. |
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*/ |
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if (WARN_ON_ONCE(IS_ERR(shp))) |
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goto done; /* no-op */ |
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|
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ipc_update_pid(&shp->shm_lprid, task_tgid(current)); |
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shp->shm_dtim = ktime_get_real_seconds(); |
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shp->shm_nattch--; |
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if (shm_may_destroy(ns, shp)) |
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shm_destroy(ns, shp); |
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else |
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shm_unlock(shp); |
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done: |
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up_write(&shm_ids(ns).rwsem); |
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} |
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|
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/* Called with ns->shm_ids(ns).rwsem locked */ |
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static int shm_try_destroy_orphaned(int id, void *p, void *data) |
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{ |
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struct ipc_namespace *ns = data; |
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struct kern_ipc_perm *ipcp = p; |
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struct shmid_kernel *shp = container_of(ipcp, struct shmid_kernel, shm_perm); |
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|
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/* |
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* We want to destroy segments without users and with already |
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* exit'ed originating process. |
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* |
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* As shp->* are changed under rwsem, it's safe to skip shp locking. |
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*/ |
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if (shp->shm_creator != NULL) |
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return 0; |
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|
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if (shm_may_destroy(ns, shp)) { |
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shm_lock_by_ptr(shp); |
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shm_destroy(ns, shp); |
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} |
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return 0; |
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} |
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|
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void shm_destroy_orphaned(struct ipc_namespace *ns) |
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{ |
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down_write(&shm_ids(ns).rwsem); |
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if (shm_ids(ns).in_use) |
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idr_for_each(&shm_ids(ns).ipcs_idr, &shm_try_destroy_orphaned, ns); |
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up_write(&shm_ids(ns).rwsem); |
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} |
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|
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/* Locking assumes this will only be called with task == current */ |
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void exit_shm(struct task_struct *task) |
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{ |
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struct ipc_namespace *ns = task->nsproxy->ipc_ns; |
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struct shmid_kernel *shp, *n; |
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|
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if (list_empty(&task->sysvshm.shm_clist)) |
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return; |
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|
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/* |
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* If kernel.shm_rmid_forced is not set then only keep track of |
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* which shmids are orphaned, so that a later set of the sysctl |
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* can clean them up. |
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*/ |
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if (!ns->shm_rmid_forced) { |
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down_read(&shm_ids(ns).rwsem); |
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list_for_each_entry(shp, &task->sysvshm.shm_clist, shm_clist) |
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shp->shm_creator = NULL; |
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/* |
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* Only under read lock but we are only called on current |
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* so no entry on the list will be shared. |
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*/ |
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list_del(&task->sysvshm.shm_clist); |
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up_read(&shm_ids(ns).rwsem); |
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return; |
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} |
|
|
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/* |
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* Destroy all already created segments, that were not yet mapped, |
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* and mark any mapped as orphan to cover the sysctl toggling. |
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* Destroy is skipped if shm_may_destroy() returns false. |
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*/ |
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down_write(&shm_ids(ns).rwsem); |
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list_for_each_entry_safe(shp, n, &task->sysvshm.shm_clist, shm_clist) { |
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shp->shm_creator = NULL; |
|
|
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if (shm_may_destroy(ns, shp)) { |
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shm_lock_by_ptr(shp); |
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shm_destroy(ns, shp); |
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} |
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} |
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|
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/* Remove the list head from any segments still attached. */ |
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list_del(&task->sysvshm.shm_clist); |
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up_write(&shm_ids(ns).rwsem); |
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} |
|
|
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static vm_fault_t shm_fault(struct vm_fault *vmf) |
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{ |
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struct file *file = vmf->vma->vm_file; |
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struct shm_file_data *sfd = shm_file_data(file); |
|
|
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return sfd->vm_ops->fault(vmf); |
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} |
|
|
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static int shm_may_split(struct vm_area_struct *vma, unsigned long addr) |
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{ |
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struct file *file = vma->vm_file; |
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struct shm_file_data *sfd = shm_file_data(file); |
|
|
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if (sfd->vm_ops->may_split) |
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return sfd->vm_ops->may_split(vma, addr); |
|
|
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return 0; |
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} |
|
|
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static unsigned long shm_pagesize(struct vm_area_struct *vma) |
|
{ |
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struct file *file = vma->vm_file; |
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struct shm_file_data *sfd = shm_file_data(file); |
|
|
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if (sfd->vm_ops->pagesize) |
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return sfd->vm_ops->pagesize(vma); |
|
|
|
return PAGE_SIZE; |
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} |
|
|
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#ifdef CONFIG_NUMA |
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static int shm_set_policy(struct vm_area_struct *vma, struct mempolicy *new) |
|
{ |
|
struct file *file = vma->vm_file; |
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struct shm_file_data *sfd = shm_file_data(file); |
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int err = 0; |
|
|
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if (sfd->vm_ops->set_policy) |
|
err = sfd->vm_ops->set_policy(vma, new); |
|
return err; |
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} |
|
|
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static struct mempolicy *shm_get_policy(struct vm_area_struct *vma, |
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unsigned long addr) |
|
{ |
|
struct file *file = vma->vm_file; |
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struct shm_file_data *sfd = shm_file_data(file); |
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struct mempolicy *pol = NULL; |
|
|
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if (sfd->vm_ops->get_policy) |
|
pol = sfd->vm_ops->get_policy(vma, addr); |
|
else if (vma->vm_policy) |
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pol = vma->vm_policy; |
|
|
|
return pol; |
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} |
|
#endif |
|
|
|
static int shm_mmap(struct file *file, struct vm_area_struct *vma) |
|
{ |
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struct shm_file_data *sfd = shm_file_data(file); |
|
int ret; |
|
|
|
/* |
|
* In case of remap_file_pages() emulation, the file can represent an |
|
* IPC ID that was removed, and possibly even reused by another shm |
|
* segment already. Propagate this case as an error to caller. |
|
*/ |
|
ret = __shm_open(vma); |
|
if (ret) |
|
return ret; |
|
|
|
ret = call_mmap(sfd->file, vma); |
|
if (ret) { |
|
shm_close(vma); |
|
return ret; |
|
} |
|
sfd->vm_ops = vma->vm_ops; |
|
#ifdef CONFIG_MMU |
|
WARN_ON(!sfd->vm_ops->fault); |
|
#endif |
|
vma->vm_ops = &shm_vm_ops; |
|
return 0; |
|
} |
|
|
|
static int shm_release(struct inode *ino, struct file *file) |
|
{ |
|
struct shm_file_data *sfd = shm_file_data(file); |
|
|
|
put_ipc_ns(sfd->ns); |
|
fput(sfd->file); |
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shm_file_data(file) = NULL; |
|
kfree(sfd); |
|
return 0; |
|
} |
|
|
|
static int shm_fsync(struct file *file, loff_t start, loff_t end, int datasync) |
|
{ |
|
struct shm_file_data *sfd = shm_file_data(file); |
|
|
|
if (!sfd->file->f_op->fsync) |
|
return -EINVAL; |
|
return sfd->file->f_op->fsync(sfd->file, start, end, datasync); |
|
} |
|
|
|
static long shm_fallocate(struct file *file, int mode, loff_t offset, |
|
loff_t len) |
|
{ |
|
struct shm_file_data *sfd = shm_file_data(file); |
|
|
|
if (!sfd->file->f_op->fallocate) |
|
return -EOPNOTSUPP; |
|
return sfd->file->f_op->fallocate(file, mode, offset, len); |
|
} |
|
|
|
static unsigned long shm_get_unmapped_area(struct file *file, |
|
unsigned long addr, unsigned long len, unsigned long pgoff, |
|
unsigned long flags) |
|
{ |
|
struct shm_file_data *sfd = shm_file_data(file); |
|
|
|
return sfd->file->f_op->get_unmapped_area(sfd->file, addr, len, |
|
pgoff, flags); |
|
} |
|
|
|
static const struct file_operations shm_file_operations = { |
|
.mmap = shm_mmap, |
|
.fsync = shm_fsync, |
|
.release = shm_release, |
|
.get_unmapped_area = shm_get_unmapped_area, |
|
.llseek = noop_llseek, |
|
.fallocate = shm_fallocate, |
|
}; |
|
|
|
/* |
|
* shm_file_operations_huge is now identical to shm_file_operations, |
|
* but we keep it distinct for the sake of is_file_shm_hugepages(). |
|
*/ |
|
static const struct file_operations shm_file_operations_huge = { |
|
.mmap = shm_mmap, |
|
.fsync = shm_fsync, |
|
.release = shm_release, |
|
.get_unmapped_area = shm_get_unmapped_area, |
|
.llseek = noop_llseek, |
|
.fallocate = shm_fallocate, |
|
}; |
|
|
|
bool is_file_shm_hugepages(struct file *file) |
|
{ |
|
return file->f_op == &shm_file_operations_huge; |
|
} |
|
|
|
static const struct vm_operations_struct shm_vm_ops = { |
|
.open = shm_open, /* callback for a new vm-area open */ |
|
.close = shm_close, /* callback for when the vm-area is released */ |
|
.fault = shm_fault, |
|
.may_split = shm_may_split, |
|
.pagesize = shm_pagesize, |
|
#if defined(CONFIG_NUMA) |
|
.set_policy = shm_set_policy, |
|
.get_policy = shm_get_policy, |
|
#endif |
|
}; |
|
|
|
/** |
|
* newseg - Create a new shared memory segment |
|
* @ns: namespace |
|
* @params: ptr to the structure that contains key, size and shmflg |
|
* |
|
* Called with shm_ids.rwsem held as a writer. |
|
*/ |
|
static int newseg(struct ipc_namespace *ns, struct ipc_params *params) |
|
{ |
|
key_t key = params->key; |
|
int shmflg = params->flg; |
|
size_t size = params->u.size; |
|
int error; |
|
struct shmid_kernel *shp; |
|
size_t numpages = (size + PAGE_SIZE - 1) >> PAGE_SHIFT; |
|
struct file *file; |
|
char name[13]; |
|
vm_flags_t acctflag = 0; |
|
|
|
if (size < SHMMIN || size > ns->shm_ctlmax) |
|
return -EINVAL; |
|
|
|
if (numpages << PAGE_SHIFT < size) |
|
return -ENOSPC; |
|
|
|
if (ns->shm_tot + numpages < ns->shm_tot || |
|
ns->shm_tot + numpages > ns->shm_ctlall) |
|
return -ENOSPC; |
|
|
|
shp = kmalloc(sizeof(*shp), GFP_KERNEL_ACCOUNT); |
|
if (unlikely(!shp)) |
|
return -ENOMEM; |
|
|
|
shp->shm_perm.key = key; |
|
shp->shm_perm.mode = (shmflg & S_IRWXUGO); |
|
shp->mlock_ucounts = NULL; |
|
|
|
shp->shm_perm.security = NULL; |
|
error = security_shm_alloc(&shp->shm_perm); |
|
if (error) { |
|
kfree(shp); |
|
return error; |
|
} |
|
|
|
sprintf(name, "SYSV%08x", key); |
|
if (shmflg & SHM_HUGETLB) { |
|
struct hstate *hs; |
|
size_t hugesize; |
|
|
|
hs = hstate_sizelog((shmflg >> SHM_HUGE_SHIFT) & SHM_HUGE_MASK); |
|
if (!hs) { |
|
error = -EINVAL; |
|
goto no_file; |
|
} |
|
hugesize = ALIGN(size, huge_page_size(hs)); |
|
|
|
/* hugetlb_file_setup applies strict accounting */ |
|
if (shmflg & SHM_NORESERVE) |
|
acctflag = VM_NORESERVE; |
|
file = hugetlb_file_setup(name, hugesize, acctflag, |
|
&shp->mlock_ucounts, HUGETLB_SHMFS_INODE, |
|
(shmflg >> SHM_HUGE_SHIFT) & SHM_HUGE_MASK); |
|
} else { |
|
/* |
|
* Do not allow no accounting for OVERCOMMIT_NEVER, even |
|
* if it's asked for. |
|
*/ |
|
if ((shmflg & SHM_NORESERVE) && |
|
sysctl_overcommit_memory != OVERCOMMIT_NEVER) |
|
acctflag = VM_NORESERVE; |
|
file = shmem_kernel_file_setup(name, size, acctflag); |
|
} |
|
error = PTR_ERR(file); |
|
if (IS_ERR(file)) |
|
goto no_file; |
|
|
|
shp->shm_cprid = get_pid(task_tgid(current)); |
|
shp->shm_lprid = NULL; |
|
shp->shm_atim = shp->shm_dtim = 0; |
|
shp->shm_ctim = ktime_get_real_seconds(); |
|
shp->shm_segsz = size; |
|
shp->shm_nattch = 0; |
|
shp->shm_file = file; |
|
shp->shm_creator = current; |
|
|
|
/* ipc_addid() locks shp upon success. */ |
|
error = ipc_addid(&shm_ids(ns), &shp->shm_perm, ns->shm_ctlmni); |
|
if (error < 0) |
|
goto no_id; |
|
|
|
list_add(&shp->shm_clist, ¤t->sysvshm.shm_clist); |
|
|
|
/* |
|
* shmid gets reported as "inode#" in /proc/pid/maps. |
|
* proc-ps tools use this. Changing this will break them. |
|
*/ |
|
file_inode(file)->i_ino = shp->shm_perm.id; |
|
|
|
ns->shm_tot += numpages; |
|
error = shp->shm_perm.id; |
|
|
|
ipc_unlock_object(&shp->shm_perm); |
|
rcu_read_unlock(); |
|
return error; |
|
|
|
no_id: |
|
ipc_update_pid(&shp->shm_cprid, NULL); |
|
ipc_update_pid(&shp->shm_lprid, NULL); |
|
if (is_file_hugepages(file) && shp->mlock_ucounts) |
|
user_shm_unlock(size, shp->mlock_ucounts); |
|
fput(file); |
|
ipc_rcu_putref(&shp->shm_perm, shm_rcu_free); |
|
return error; |
|
no_file: |
|
call_rcu(&shp->shm_perm.rcu, shm_rcu_free); |
|
return error; |
|
} |
|
|
|
/* |
|
* Called with shm_ids.rwsem and ipcp locked. |
|
*/ |
|
static int shm_more_checks(struct kern_ipc_perm *ipcp, struct ipc_params *params) |
|
{ |
|
struct shmid_kernel *shp; |
|
|
|
shp = container_of(ipcp, struct shmid_kernel, shm_perm); |
|
if (shp->shm_segsz < params->u.size) |
|
return -EINVAL; |
|
|
|
return 0; |
|
} |
|
|
|
long ksys_shmget(key_t key, size_t size, int shmflg) |
|
{ |
|
struct ipc_namespace *ns; |
|
static const struct ipc_ops shm_ops = { |
|
.getnew = newseg, |
|
.associate = security_shm_associate, |
|
.more_checks = shm_more_checks, |
|
}; |
|
struct ipc_params shm_params; |
|
|
|
ns = current->nsproxy->ipc_ns; |
|
|
|
shm_params.key = key; |
|
shm_params.flg = shmflg; |
|
shm_params.u.size = size; |
|
|
|
return ipcget(ns, &shm_ids(ns), &shm_ops, &shm_params); |
|
} |
|
|
|
SYSCALL_DEFINE3(shmget, key_t, key, size_t, size, int, shmflg) |
|
{ |
|
return ksys_shmget(key, size, shmflg); |
|
} |
|
|
|
static inline unsigned long copy_shmid_to_user(void __user *buf, struct shmid64_ds *in, int version) |
|
{ |
|
switch (version) { |
|
case IPC_64: |
|
return copy_to_user(buf, in, sizeof(*in)); |
|
case IPC_OLD: |
|
{ |
|
struct shmid_ds out; |
|
|
|
memset(&out, 0, sizeof(out)); |
|
ipc64_perm_to_ipc_perm(&in->shm_perm, &out.shm_perm); |
|
out.shm_segsz = in->shm_segsz; |
|
out.shm_atime = in->shm_atime; |
|
out.shm_dtime = in->shm_dtime; |
|
out.shm_ctime = in->shm_ctime; |
|
out.shm_cpid = in->shm_cpid; |
|
out.shm_lpid = in->shm_lpid; |
|
out.shm_nattch = in->shm_nattch; |
|
|
|
return copy_to_user(buf, &out, sizeof(out)); |
|
} |
|
default: |
|
return -EINVAL; |
|
} |
|
} |
|
|
|
static inline unsigned long |
|
copy_shmid_from_user(struct shmid64_ds *out, void __user *buf, int version) |
|
{ |
|
switch (version) { |
|
case IPC_64: |
|
if (copy_from_user(out, buf, sizeof(*out))) |
|
return -EFAULT; |
|
return 0; |
|
case IPC_OLD: |
|
{ |
|
struct shmid_ds tbuf_old; |
|
|
|
if (copy_from_user(&tbuf_old, buf, sizeof(tbuf_old))) |
|
return -EFAULT; |
|
|
|
out->shm_perm.uid = tbuf_old.shm_perm.uid; |
|
out->shm_perm.gid = tbuf_old.shm_perm.gid; |
|
out->shm_perm.mode = tbuf_old.shm_perm.mode; |
|
|
|
return 0; |
|
} |
|
default: |
|
return -EINVAL; |
|
} |
|
} |
|
|
|
static inline unsigned long copy_shminfo_to_user(void __user *buf, struct shminfo64 *in, int version) |
|
{ |
|
switch (version) { |
|
case IPC_64: |
|
return copy_to_user(buf, in, sizeof(*in)); |
|
case IPC_OLD: |
|
{ |
|
struct shminfo out; |
|
|
|
if (in->shmmax > INT_MAX) |
|
out.shmmax = INT_MAX; |
|
else |
|
out.shmmax = (int)in->shmmax; |
|
|
|
out.shmmin = in->shmmin; |
|
out.shmmni = in->shmmni; |
|
out.shmseg = in->shmseg; |
|
out.shmall = in->shmall; |
|
|
|
return copy_to_user(buf, &out, sizeof(out)); |
|
} |
|
default: |
|
return -EINVAL; |
|
} |
|
} |
|
|
|
/* |
|
* Calculate and add used RSS and swap pages of a shm. |
|
* Called with shm_ids.rwsem held as a reader |
|
*/ |
|
static void shm_add_rss_swap(struct shmid_kernel *shp, |
|
unsigned long *rss_add, unsigned long *swp_add) |
|
{ |
|
struct inode *inode; |
|
|
|
inode = file_inode(shp->shm_file); |
|
|
|
if (is_file_hugepages(shp->shm_file)) { |
|
struct address_space *mapping = inode->i_mapping; |
|
struct hstate *h = hstate_file(shp->shm_file); |
|
*rss_add += pages_per_huge_page(h) * mapping->nrpages; |
|
} else { |
|
#ifdef CONFIG_SHMEM |
|
struct shmem_inode_info *info = SHMEM_I(inode); |
|
|
|
spin_lock_irq(&info->lock); |
|
*rss_add += inode->i_mapping->nrpages; |
|
*swp_add += info->swapped; |
|
spin_unlock_irq(&info->lock); |
|
#else |
|
*rss_add += inode->i_mapping->nrpages; |
|
#endif |
|
} |
|
} |
|
|
|
/* |
|
* Called with shm_ids.rwsem held as a reader |
|
*/ |
|
static void shm_get_stat(struct ipc_namespace *ns, unsigned long *rss, |
|
unsigned long *swp) |
|
{ |
|
int next_id; |
|
int total, in_use; |
|
|
|
*rss = 0; |
|
*swp = 0; |
|
|
|
in_use = shm_ids(ns).in_use; |
|
|
|
for (total = 0, next_id = 0; total < in_use; next_id++) { |
|
struct kern_ipc_perm *ipc; |
|
struct shmid_kernel *shp; |
|
|
|
ipc = idr_find(&shm_ids(ns).ipcs_idr, next_id); |
|
if (ipc == NULL) |
|
continue; |
|
shp = container_of(ipc, struct shmid_kernel, shm_perm); |
|
|
|
shm_add_rss_swap(shp, rss, swp); |
|
|
|
total++; |
|
} |
|
} |
|
|
|
/* |
|
* This function handles some shmctl commands which require the rwsem |
|
* to be held in write mode. |
|
* NOTE: no locks must be held, the rwsem is taken inside this function. |
|
*/ |
|
static int shmctl_down(struct ipc_namespace *ns, int shmid, int cmd, |
|
struct shmid64_ds *shmid64) |
|
{ |
|
struct kern_ipc_perm *ipcp; |
|
struct shmid_kernel *shp; |
|
int err; |
|
|
|
down_write(&shm_ids(ns).rwsem); |
|
rcu_read_lock(); |
|
|
|
ipcp = ipcctl_obtain_check(ns, &shm_ids(ns), shmid, cmd, |
|
&shmid64->shm_perm, 0); |
|
if (IS_ERR(ipcp)) { |
|
err = PTR_ERR(ipcp); |
|
goto out_unlock1; |
|
} |
|
|
|
shp = container_of(ipcp, struct shmid_kernel, shm_perm); |
|
|
|
err = security_shm_shmctl(&shp->shm_perm, cmd); |
|
if (err) |
|
goto out_unlock1; |
|
|
|
switch (cmd) { |
|
case IPC_RMID: |
|
ipc_lock_object(&shp->shm_perm); |
|
/* do_shm_rmid unlocks the ipc object and rcu */ |
|
do_shm_rmid(ns, ipcp); |
|
goto out_up; |
|
case IPC_SET: |
|
ipc_lock_object(&shp->shm_perm); |
|
err = ipc_update_perm(&shmid64->shm_perm, ipcp); |
|
if (err) |
|
goto out_unlock0; |
|
shp->shm_ctim = ktime_get_real_seconds(); |
|
break; |
|
default: |
|
err = -EINVAL; |
|
goto out_unlock1; |
|
} |
|
|
|
out_unlock0: |
|
ipc_unlock_object(&shp->shm_perm); |
|
out_unlock1: |
|
rcu_read_unlock(); |
|
out_up: |
|
up_write(&shm_ids(ns).rwsem); |
|
return err; |
|
} |
|
|
|
static int shmctl_ipc_info(struct ipc_namespace *ns, |
|
struct shminfo64 *shminfo) |
|
{ |
|
int err = security_shm_shmctl(NULL, IPC_INFO); |
|
if (!err) { |
|
memset(shminfo, 0, sizeof(*shminfo)); |
|
shminfo->shmmni = shminfo->shmseg = ns->shm_ctlmni; |
|
shminfo->shmmax = ns->shm_ctlmax; |
|
shminfo->shmall = ns->shm_ctlall; |
|
shminfo->shmmin = SHMMIN; |
|
down_read(&shm_ids(ns).rwsem); |
|
err = ipc_get_maxidx(&shm_ids(ns)); |
|
up_read(&shm_ids(ns).rwsem); |
|
if (err < 0) |
|
err = 0; |
|
} |
|
return err; |
|
} |
|
|
|
static int shmctl_shm_info(struct ipc_namespace *ns, |
|
struct shm_info *shm_info) |
|
{ |
|
int err = security_shm_shmctl(NULL, SHM_INFO); |
|
if (!err) { |
|
memset(shm_info, 0, sizeof(*shm_info)); |
|
down_read(&shm_ids(ns).rwsem); |
|
shm_info->used_ids = shm_ids(ns).in_use; |
|
shm_get_stat(ns, &shm_info->shm_rss, &shm_info->shm_swp); |
|
shm_info->shm_tot = ns->shm_tot; |
|
shm_info->swap_attempts = 0; |
|
shm_info->swap_successes = 0; |
|
err = ipc_get_maxidx(&shm_ids(ns)); |
|
up_read(&shm_ids(ns).rwsem); |
|
if (err < 0) |
|
err = 0; |
|
} |
|
return err; |
|
} |
|
|
|
static int shmctl_stat(struct ipc_namespace *ns, int shmid, |
|
int cmd, struct shmid64_ds *tbuf) |
|
{ |
|
struct shmid_kernel *shp; |
|
int err; |
|
|
|
memset(tbuf, 0, sizeof(*tbuf)); |
|
|
|
rcu_read_lock(); |
|
if (cmd == SHM_STAT || cmd == SHM_STAT_ANY) { |
|
shp = shm_obtain_object(ns, shmid); |
|
if (IS_ERR(shp)) { |
|
err = PTR_ERR(shp); |
|
goto out_unlock; |
|
} |
|
} else { /* IPC_STAT */ |
|
shp = shm_obtain_object_check(ns, shmid); |
|
if (IS_ERR(shp)) { |
|
err = PTR_ERR(shp); |
|
goto out_unlock; |
|
} |
|
} |
|
|
|
/* |
|
* Semantically SHM_STAT_ANY ought to be identical to |
|
* that functionality provided by the /proc/sysvipc/ |
|
* interface. As such, only audit these calls and |
|
* do not do traditional S_IRUGO permission checks on |
|
* the ipc object. |
|
*/ |
|
if (cmd == SHM_STAT_ANY) |
|
audit_ipc_obj(&shp->shm_perm); |
|
else { |
|
err = -EACCES; |
|
if (ipcperms(ns, &shp->shm_perm, S_IRUGO)) |
|
goto out_unlock; |
|
} |
|
|
|
err = security_shm_shmctl(&shp->shm_perm, cmd); |
|
if (err) |
|
goto out_unlock; |
|
|
|
ipc_lock_object(&shp->shm_perm); |
|
|
|
if (!ipc_valid_object(&shp->shm_perm)) { |
|
ipc_unlock_object(&shp->shm_perm); |
|
err = -EIDRM; |
|
goto out_unlock; |
|
} |
|
|
|
kernel_to_ipc64_perm(&shp->shm_perm, &tbuf->shm_perm); |
|
tbuf->shm_segsz = shp->shm_segsz; |
|
tbuf->shm_atime = shp->shm_atim; |
|
tbuf->shm_dtime = shp->shm_dtim; |
|
tbuf->shm_ctime = shp->shm_ctim; |
|
#ifndef CONFIG_64BIT |
|
tbuf->shm_atime_high = shp->shm_atim >> 32; |
|
tbuf->shm_dtime_high = shp->shm_dtim >> 32; |
|
tbuf->shm_ctime_high = shp->shm_ctim >> 32; |
|
#endif |
|
tbuf->shm_cpid = pid_vnr(shp->shm_cprid); |
|
tbuf->shm_lpid = pid_vnr(shp->shm_lprid); |
|
tbuf->shm_nattch = shp->shm_nattch; |
|
|
|
if (cmd == IPC_STAT) { |
|
/* |
|
* As defined in SUS: |
|
* Return 0 on success |
|
*/ |
|
err = 0; |
|
} else { |
|
/* |
|
* SHM_STAT and SHM_STAT_ANY (both Linux specific) |
|
* Return the full id, including the sequence number |
|
*/ |
|
err = shp->shm_perm.id; |
|
} |
|
|
|
ipc_unlock_object(&shp->shm_perm); |
|
out_unlock: |
|
rcu_read_unlock(); |
|
return err; |
|
} |
|
|
|
static int shmctl_do_lock(struct ipc_namespace *ns, int shmid, int cmd) |
|
{ |
|
struct shmid_kernel *shp; |
|
struct file *shm_file; |
|
int err; |
|
|
|
rcu_read_lock(); |
|
shp = shm_obtain_object_check(ns, shmid); |
|
if (IS_ERR(shp)) { |
|
err = PTR_ERR(shp); |
|
goto out_unlock1; |
|
} |
|
|
|
audit_ipc_obj(&(shp->shm_perm)); |
|
err = security_shm_shmctl(&shp->shm_perm, cmd); |
|
if (err) |
|
goto out_unlock1; |
|
|
|
ipc_lock_object(&shp->shm_perm); |
|
|
|
/* check if shm_destroy() is tearing down shp */ |
|
if (!ipc_valid_object(&shp->shm_perm)) { |
|
err = -EIDRM; |
|
goto out_unlock0; |
|
} |
|
|
|
if (!ns_capable(ns->user_ns, CAP_IPC_LOCK)) { |
|
kuid_t euid = current_euid(); |
|
|
|
if (!uid_eq(euid, shp->shm_perm.uid) && |
|
!uid_eq(euid, shp->shm_perm.cuid)) { |
|
err = -EPERM; |
|
goto out_unlock0; |
|
} |
|
if (cmd == SHM_LOCK && !rlimit(RLIMIT_MEMLOCK)) { |
|
err = -EPERM; |
|
goto out_unlock0; |
|
} |
|
} |
|
|
|
shm_file = shp->shm_file; |
|
if (is_file_hugepages(shm_file)) |
|
goto out_unlock0; |
|
|
|
if (cmd == SHM_LOCK) { |
|
struct ucounts *ucounts = current_ucounts(); |
|
|
|
err = shmem_lock(shm_file, 1, ucounts); |
|
if (!err && !(shp->shm_perm.mode & SHM_LOCKED)) { |
|
shp->shm_perm.mode |= SHM_LOCKED; |
|
shp->mlock_ucounts = ucounts; |
|
} |
|
goto out_unlock0; |
|
} |
|
|
|
/* SHM_UNLOCK */ |
|
if (!(shp->shm_perm.mode & SHM_LOCKED)) |
|
goto out_unlock0; |
|
shmem_lock(shm_file, 0, shp->mlock_ucounts); |
|
shp->shm_perm.mode &= ~SHM_LOCKED; |
|
shp->mlock_ucounts = NULL; |
|
get_file(shm_file); |
|
ipc_unlock_object(&shp->shm_perm); |
|
rcu_read_unlock(); |
|
shmem_unlock_mapping(shm_file->f_mapping); |
|
|
|
fput(shm_file); |
|
return err; |
|
|
|
out_unlock0: |
|
ipc_unlock_object(&shp->shm_perm); |
|
out_unlock1: |
|
rcu_read_unlock(); |
|
return err; |
|
} |
|
|
|
static long ksys_shmctl(int shmid, int cmd, struct shmid_ds __user *buf, int version) |
|
{ |
|
int err; |
|
struct ipc_namespace *ns; |
|
struct shmid64_ds sem64; |
|
|
|
if (cmd < 0 || shmid < 0) |
|
return -EINVAL; |
|
|
|
ns = current->nsproxy->ipc_ns; |
|
|
|
switch (cmd) { |
|
case IPC_INFO: { |
|
struct shminfo64 shminfo; |
|
err = shmctl_ipc_info(ns, &shminfo); |
|
if (err < 0) |
|
return err; |
|
if (copy_shminfo_to_user(buf, &shminfo, version)) |
|
err = -EFAULT; |
|
return err; |
|
} |
|
case SHM_INFO: { |
|
struct shm_info shm_info; |
|
err = shmctl_shm_info(ns, &shm_info); |
|
if (err < 0) |
|
return err; |
|
if (copy_to_user(buf, &shm_info, sizeof(shm_info))) |
|
err = -EFAULT; |
|
return err; |
|
} |
|
case SHM_STAT: |
|
case SHM_STAT_ANY: |
|
case IPC_STAT: { |
|
err = shmctl_stat(ns, shmid, cmd, &sem64); |
|
if (err < 0) |
|
return err; |
|
if (copy_shmid_to_user(buf, &sem64, version)) |
|
err = -EFAULT; |
|
return err; |
|
} |
|
case IPC_SET: |
|
if (copy_shmid_from_user(&sem64, buf, version)) |
|
return -EFAULT; |
|
fallthrough; |
|
case IPC_RMID: |
|
return shmctl_down(ns, shmid, cmd, &sem64); |
|
case SHM_LOCK: |
|
case SHM_UNLOCK: |
|
return shmctl_do_lock(ns, shmid, cmd); |
|
default: |
|
return -EINVAL; |
|
} |
|
} |
|
|
|
SYSCALL_DEFINE3(shmctl, int, shmid, int, cmd, struct shmid_ds __user *, buf) |
|
{ |
|
return ksys_shmctl(shmid, cmd, buf, IPC_64); |
|
} |
|
|
|
#ifdef CONFIG_ARCH_WANT_IPC_PARSE_VERSION |
|
long ksys_old_shmctl(int shmid, int cmd, struct shmid_ds __user *buf) |
|
{ |
|
int version = ipc_parse_version(&cmd); |
|
|
|
return ksys_shmctl(shmid, cmd, buf, version); |
|
} |
|
|
|
SYSCALL_DEFINE3(old_shmctl, int, shmid, int, cmd, struct shmid_ds __user *, buf) |
|
{ |
|
return ksys_old_shmctl(shmid, cmd, buf); |
|
} |
|
#endif |
|
|
|
#ifdef CONFIG_COMPAT |
|
|
|
struct compat_shmid_ds { |
|
struct compat_ipc_perm shm_perm; |
|
int shm_segsz; |
|
old_time32_t shm_atime; |
|
old_time32_t shm_dtime; |
|
old_time32_t shm_ctime; |
|
compat_ipc_pid_t shm_cpid; |
|
compat_ipc_pid_t shm_lpid; |
|
unsigned short shm_nattch; |
|
unsigned short shm_unused; |
|
compat_uptr_t shm_unused2; |
|
compat_uptr_t shm_unused3; |
|
}; |
|
|
|
struct compat_shminfo64 { |
|
compat_ulong_t shmmax; |
|
compat_ulong_t shmmin; |
|
compat_ulong_t shmmni; |
|
compat_ulong_t shmseg; |
|
compat_ulong_t shmall; |
|
compat_ulong_t __unused1; |
|
compat_ulong_t __unused2; |
|
compat_ulong_t __unused3; |
|
compat_ulong_t __unused4; |
|
}; |
|
|
|
struct compat_shm_info { |
|
compat_int_t used_ids; |
|
compat_ulong_t shm_tot, shm_rss, shm_swp; |
|
compat_ulong_t swap_attempts, swap_successes; |
|
}; |
|
|
|
static int copy_compat_shminfo_to_user(void __user *buf, struct shminfo64 *in, |
|
int version) |
|
{ |
|
if (in->shmmax > INT_MAX) |
|
in->shmmax = INT_MAX; |
|
if (version == IPC_64) { |
|
struct compat_shminfo64 info; |
|
memset(&info, 0, sizeof(info)); |
|
info.shmmax = in->shmmax; |
|
info.shmmin = in->shmmin; |
|
info.shmmni = in->shmmni; |
|
info.shmseg = in->shmseg; |
|
info.shmall = in->shmall; |
|
return copy_to_user(buf, &info, sizeof(info)); |
|
} else { |
|
struct shminfo info; |
|
memset(&info, 0, sizeof(info)); |
|
info.shmmax = in->shmmax; |
|
info.shmmin = in->shmmin; |
|
info.shmmni = in->shmmni; |
|
info.shmseg = in->shmseg; |
|
info.shmall = in->shmall; |
|
return copy_to_user(buf, &info, sizeof(info)); |
|
} |
|
} |
|
|
|
static int put_compat_shm_info(struct shm_info *ip, |
|
struct compat_shm_info __user *uip) |
|
{ |
|
struct compat_shm_info info; |
|
|
|
memset(&info, 0, sizeof(info)); |
|
info.used_ids = ip->used_ids; |
|
info.shm_tot = ip->shm_tot; |
|
info.shm_rss = ip->shm_rss; |
|
info.shm_swp = ip->shm_swp; |
|
info.swap_attempts = ip->swap_attempts; |
|
info.swap_successes = ip->swap_successes; |
|
return copy_to_user(uip, &info, sizeof(info)); |
|
} |
|
|
|
static int copy_compat_shmid_to_user(void __user *buf, struct shmid64_ds *in, |
|
int version) |
|
{ |
|
if (version == IPC_64) { |
|
struct compat_shmid64_ds v; |
|
memset(&v, 0, sizeof(v)); |
|
to_compat_ipc64_perm(&v.shm_perm, &in->shm_perm); |
|
v.shm_atime = lower_32_bits(in->shm_atime); |
|
v.shm_atime_high = upper_32_bits(in->shm_atime); |
|
v.shm_dtime = lower_32_bits(in->shm_dtime); |
|
v.shm_dtime_high = upper_32_bits(in->shm_dtime); |
|
v.shm_ctime = lower_32_bits(in->shm_ctime); |
|
v.shm_ctime_high = upper_32_bits(in->shm_ctime); |
|
v.shm_segsz = in->shm_segsz; |
|
v.shm_nattch = in->shm_nattch; |
|
v.shm_cpid = in->shm_cpid; |
|
v.shm_lpid = in->shm_lpid; |
|
return copy_to_user(buf, &v, sizeof(v)); |
|
} else { |
|
struct compat_shmid_ds v; |
|
memset(&v, 0, sizeof(v)); |
|
to_compat_ipc_perm(&v.shm_perm, &in->shm_perm); |
|
v.shm_perm.key = in->shm_perm.key; |
|
v.shm_atime = in->shm_atime; |
|
v.shm_dtime = in->shm_dtime; |
|
v.shm_ctime = in->shm_ctime; |
|
v.shm_segsz = in->shm_segsz; |
|
v.shm_nattch = in->shm_nattch; |
|
v.shm_cpid = in->shm_cpid; |
|
v.shm_lpid = in->shm_lpid; |
|
return copy_to_user(buf, &v, sizeof(v)); |
|
} |
|
} |
|
|
|
static int copy_compat_shmid_from_user(struct shmid64_ds *out, void __user *buf, |
|
int version) |
|
{ |
|
memset(out, 0, sizeof(*out)); |
|
if (version == IPC_64) { |
|
struct compat_shmid64_ds __user *p = buf; |
|
return get_compat_ipc64_perm(&out->shm_perm, &p->shm_perm); |
|
} else { |
|
struct compat_shmid_ds __user *p = buf; |
|
return get_compat_ipc_perm(&out->shm_perm, &p->shm_perm); |
|
} |
|
} |
|
|
|
static long compat_ksys_shmctl(int shmid, int cmd, void __user *uptr, int version) |
|
{ |
|
struct ipc_namespace *ns; |
|
struct shmid64_ds sem64; |
|
int err; |
|
|
|
ns = current->nsproxy->ipc_ns; |
|
|
|
if (cmd < 0 || shmid < 0) |
|
return -EINVAL; |
|
|
|
switch (cmd) { |
|
case IPC_INFO: { |
|
struct shminfo64 shminfo; |
|
err = shmctl_ipc_info(ns, &shminfo); |
|
if (err < 0) |
|
return err; |
|
if (copy_compat_shminfo_to_user(uptr, &shminfo, version)) |
|
err = -EFAULT; |
|
return err; |
|
} |
|
case SHM_INFO: { |
|
struct shm_info shm_info; |
|
err = shmctl_shm_info(ns, &shm_info); |
|
if (err < 0) |
|
return err; |
|
if (put_compat_shm_info(&shm_info, uptr)) |
|
err = -EFAULT; |
|
return err; |
|
} |
|
case IPC_STAT: |
|
case SHM_STAT_ANY: |
|
case SHM_STAT: |
|
err = shmctl_stat(ns, shmid, cmd, &sem64); |
|
if (err < 0) |
|
return err; |
|
if (copy_compat_shmid_to_user(uptr, &sem64, version)) |
|
err = -EFAULT; |
|
return err; |
|
|
|
case IPC_SET: |
|
if (copy_compat_shmid_from_user(&sem64, uptr, version)) |
|
return -EFAULT; |
|
fallthrough; |
|
case IPC_RMID: |
|
return shmctl_down(ns, shmid, cmd, &sem64); |
|
case SHM_LOCK: |
|
case SHM_UNLOCK: |
|
return shmctl_do_lock(ns, shmid, cmd); |
|
default: |
|
return -EINVAL; |
|
} |
|
return err; |
|
} |
|
|
|
COMPAT_SYSCALL_DEFINE3(shmctl, int, shmid, int, cmd, void __user *, uptr) |
|
{ |
|
return compat_ksys_shmctl(shmid, cmd, uptr, IPC_64); |
|
} |
|
|
|
#ifdef CONFIG_ARCH_WANT_COMPAT_IPC_PARSE_VERSION |
|
long compat_ksys_old_shmctl(int shmid, int cmd, void __user *uptr) |
|
{ |
|
int version = compat_ipc_parse_version(&cmd); |
|
|
|
return compat_ksys_shmctl(shmid, cmd, uptr, version); |
|
} |
|
|
|
COMPAT_SYSCALL_DEFINE3(old_shmctl, int, shmid, int, cmd, void __user *, uptr) |
|
{ |
|
return compat_ksys_old_shmctl(shmid, cmd, uptr); |
|
} |
|
#endif |
|
#endif |
|
|
|
/* |
|
* Fix shmaddr, allocate descriptor, map shm, add attach descriptor to lists. |
|
* |
|
* NOTE! Despite the name, this is NOT a direct system call entrypoint. The |
|
* "raddr" thing points to kernel space, and there has to be a wrapper around |
|
* this. |
|
*/ |
|
long do_shmat(int shmid, char __user *shmaddr, int shmflg, |
|
ulong *raddr, unsigned long shmlba) |
|
{ |
|
struct shmid_kernel *shp; |
|
unsigned long addr = (unsigned long)shmaddr; |
|
unsigned long size; |
|
struct file *file, *base; |
|
int err; |
|
unsigned long flags = MAP_SHARED; |
|
unsigned long prot; |
|
int acc_mode; |
|
struct ipc_namespace *ns; |
|
struct shm_file_data *sfd; |
|
int f_flags; |
|
unsigned long populate = 0; |
|
|
|
err = -EINVAL; |
|
if (shmid < 0) |
|
goto out; |
|
|
|
if (addr) { |
|
if (addr & (shmlba - 1)) { |
|
if (shmflg & SHM_RND) { |
|
addr &= ~(shmlba - 1); /* round down */ |
|
|
|
/* |
|
* Ensure that the round-down is non-nil |
|
* when remapping. This can happen for |
|
* cases when addr < shmlba. |
|
*/ |
|
if (!addr && (shmflg & SHM_REMAP)) |
|
goto out; |
|
} else |
|
#ifndef __ARCH_FORCE_SHMLBA |
|
if (addr & ~PAGE_MASK) |
|
#endif |
|
goto out; |
|
} |
|
|
|
flags |= MAP_FIXED; |
|
} else if ((shmflg & SHM_REMAP)) |
|
goto out; |
|
|
|
if (shmflg & SHM_RDONLY) { |
|
prot = PROT_READ; |
|
acc_mode = S_IRUGO; |
|
f_flags = O_RDONLY; |
|
} else { |
|
prot = PROT_READ | PROT_WRITE; |
|
acc_mode = S_IRUGO | S_IWUGO; |
|
f_flags = O_RDWR; |
|
} |
|
if (shmflg & SHM_EXEC) { |
|
prot |= PROT_EXEC; |
|
acc_mode |= S_IXUGO; |
|
} |
|
|
|
/* |
|
* We cannot rely on the fs check since SYSV IPC does have an |
|
* additional creator id... |
|
*/ |
|
ns = current->nsproxy->ipc_ns; |
|
rcu_read_lock(); |
|
shp = shm_obtain_object_check(ns, shmid); |
|
if (IS_ERR(shp)) { |
|
err = PTR_ERR(shp); |
|
goto out_unlock; |
|
} |
|
|
|
err = -EACCES; |
|
if (ipcperms(ns, &shp->shm_perm, acc_mode)) |
|
goto out_unlock; |
|
|
|
err = security_shm_shmat(&shp->shm_perm, shmaddr, shmflg); |
|
if (err) |
|
goto out_unlock; |
|
|
|
ipc_lock_object(&shp->shm_perm); |
|
|
|
/* check if shm_destroy() is tearing down shp */ |
|
if (!ipc_valid_object(&shp->shm_perm)) { |
|
ipc_unlock_object(&shp->shm_perm); |
|
err = -EIDRM; |
|
goto out_unlock; |
|
} |
|
|
|
/* |
|
* We need to take a reference to the real shm file to prevent the |
|
* pointer from becoming stale in cases where the lifetime of the outer |
|
* file extends beyond that of the shm segment. It's not usually |
|
* possible, but it can happen during remap_file_pages() emulation as |
|
* that unmaps the memory, then does ->mmap() via file reference only. |
|
* We'll deny the ->mmap() if the shm segment was since removed, but to |
|
* detect shm ID reuse we need to compare the file pointers. |
|
*/ |
|
base = get_file(shp->shm_file); |
|
shp->shm_nattch++; |
|
size = i_size_read(file_inode(base)); |
|
ipc_unlock_object(&shp->shm_perm); |
|
rcu_read_unlock(); |
|
|
|
err = -ENOMEM; |
|
sfd = kzalloc(sizeof(*sfd), GFP_KERNEL); |
|
if (!sfd) { |
|
fput(base); |
|
goto out_nattch; |
|
} |
|
|
|
file = alloc_file_clone(base, f_flags, |
|
is_file_hugepages(base) ? |
|
&shm_file_operations_huge : |
|
&shm_file_operations); |
|
err = PTR_ERR(file); |
|
if (IS_ERR(file)) { |
|
kfree(sfd); |
|
fput(base); |
|
goto out_nattch; |
|
} |
|
|
|
sfd->id = shp->shm_perm.id; |
|
sfd->ns = get_ipc_ns(ns); |
|
sfd->file = base; |
|
sfd->vm_ops = NULL; |
|
file->private_data = sfd; |
|
|
|
err = security_mmap_file(file, prot, flags); |
|
if (err) |
|
goto out_fput; |
|
|
|
if (mmap_write_lock_killable(current->mm)) { |
|
err = -EINTR; |
|
goto out_fput; |
|
} |
|
|
|
if (addr && !(shmflg & SHM_REMAP)) { |
|
err = -EINVAL; |
|
if (addr + size < addr) |
|
goto invalid; |
|
|
|
if (find_vma_intersection(current->mm, addr, addr + size)) |
|
goto invalid; |
|
} |
|
|
|
addr = do_mmap(file, addr, size, prot, flags, 0, &populate, NULL); |
|
*raddr = addr; |
|
err = 0; |
|
if (IS_ERR_VALUE(addr)) |
|
err = (long)addr; |
|
invalid: |
|
mmap_write_unlock(current->mm); |
|
if (populate) |
|
mm_populate(addr, populate); |
|
|
|
out_fput: |
|
fput(file); |
|
|
|
out_nattch: |
|
down_write(&shm_ids(ns).rwsem); |
|
shp = shm_lock(ns, shmid); |
|
shp->shm_nattch--; |
|
if (shm_may_destroy(ns, shp)) |
|
shm_destroy(ns, shp); |
|
else |
|
shm_unlock(shp); |
|
up_write(&shm_ids(ns).rwsem); |
|
return err; |
|
|
|
out_unlock: |
|
rcu_read_unlock(); |
|
out: |
|
return err; |
|
} |
|
|
|
SYSCALL_DEFINE3(shmat, int, shmid, char __user *, shmaddr, int, shmflg) |
|
{ |
|
unsigned long ret; |
|
long err; |
|
|
|
err = do_shmat(shmid, shmaddr, shmflg, &ret, SHMLBA); |
|
if (err) |
|
return err; |
|
force_successful_syscall_return(); |
|
return (long)ret; |
|
} |
|
|
|
#ifdef CONFIG_COMPAT |
|
|
|
#ifndef COMPAT_SHMLBA |
|
#define COMPAT_SHMLBA SHMLBA |
|
#endif |
|
|
|
COMPAT_SYSCALL_DEFINE3(shmat, int, shmid, compat_uptr_t, shmaddr, int, shmflg) |
|
{ |
|
unsigned long ret; |
|
long err; |
|
|
|
err = do_shmat(shmid, compat_ptr(shmaddr), shmflg, &ret, COMPAT_SHMLBA); |
|
if (err) |
|
return err; |
|
force_successful_syscall_return(); |
|
return (long)ret; |
|
} |
|
#endif |
|
|
|
/* |
|
* detach and kill segment if marked destroyed. |
|
* The work is done in shm_close. |
|
*/ |
|
long ksys_shmdt(char __user *shmaddr) |
|
{ |
|
struct mm_struct *mm = current->mm; |
|
struct vm_area_struct *vma; |
|
unsigned long addr = (unsigned long)shmaddr; |
|
int retval = -EINVAL; |
|
#ifdef CONFIG_MMU |
|
loff_t size = 0; |
|
struct file *file; |
|
struct vm_area_struct *next; |
|
#endif |
|
|
|
if (addr & ~PAGE_MASK) |
|
return retval; |
|
|
|
if (mmap_write_lock_killable(mm)) |
|
return -EINTR; |
|
|
|
/* |
|
* This function tries to be smart and unmap shm segments that |
|
* were modified by partial mlock or munmap calls: |
|
* - It first determines the size of the shm segment that should be |
|
* unmapped: It searches for a vma that is backed by shm and that |
|
* started at address shmaddr. It records it's size and then unmaps |
|
* it. |
|
* - Then it unmaps all shm vmas that started at shmaddr and that |
|
* are within the initially determined size and that are from the |
|
* same shm segment from which we determined the size. |
|
* Errors from do_munmap are ignored: the function only fails if |
|
* it's called with invalid parameters or if it's called to unmap |
|
* a part of a vma. Both calls in this function are for full vmas, |
|
* the parameters are directly copied from the vma itself and always |
|
* valid - therefore do_munmap cannot fail. (famous last words?) |
|
*/ |
|
/* |
|
* If it had been mremap()'d, the starting address would not |
|
* match the usual checks anyway. So assume all vma's are |
|
* above the starting address given. |
|
*/ |
|
vma = find_vma(mm, addr); |
|
|
|
#ifdef CONFIG_MMU |
|
while (vma) { |
|
next = vma->vm_next; |
|
|
|
/* |
|
* Check if the starting address would match, i.e. it's |
|
* a fragment created by mprotect() and/or munmap(), or it |
|
* otherwise it starts at this address with no hassles. |
|
*/ |
|
if ((vma->vm_ops == &shm_vm_ops) && |
|
(vma->vm_start - addr)/PAGE_SIZE == vma->vm_pgoff) { |
|
|
|
/* |
|
* Record the file of the shm segment being |
|
* unmapped. With mremap(), someone could place |
|
* page from another segment but with equal offsets |
|
* in the range we are unmapping. |
|
*/ |
|
file = vma->vm_file; |
|
size = i_size_read(file_inode(vma->vm_file)); |
|
do_munmap(mm, vma->vm_start, vma->vm_end - vma->vm_start, NULL); |
|
/* |
|
* We discovered the size of the shm segment, so |
|
* break out of here and fall through to the next |
|
* loop that uses the size information to stop |
|
* searching for matching vma's. |
|
*/ |
|
retval = 0; |
|
vma = next; |
|
break; |
|
} |
|
vma = next; |
|
} |
|
|
|
/* |
|
* We need look no further than the maximum address a fragment |
|
* could possibly have landed at. Also cast things to loff_t to |
|
* prevent overflows and make comparisons vs. equal-width types. |
|
*/ |
|
size = PAGE_ALIGN(size); |
|
while (vma && (loff_t)(vma->vm_end - addr) <= size) { |
|
next = vma->vm_next; |
|
|
|
/* finding a matching vma now does not alter retval */ |
|
if ((vma->vm_ops == &shm_vm_ops) && |
|
((vma->vm_start - addr)/PAGE_SIZE == vma->vm_pgoff) && |
|
(vma->vm_file == file)) |
|
do_munmap(mm, vma->vm_start, vma->vm_end - vma->vm_start, NULL); |
|
vma = next; |
|
} |
|
|
|
#else /* CONFIG_MMU */ |
|
/* under NOMMU conditions, the exact address to be destroyed must be |
|
* given |
|
*/ |
|
if (vma && vma->vm_start == addr && vma->vm_ops == &shm_vm_ops) { |
|
do_munmap(mm, vma->vm_start, vma->vm_end - vma->vm_start, NULL); |
|
retval = 0; |
|
} |
|
|
|
#endif |
|
|
|
mmap_write_unlock(mm); |
|
return retval; |
|
} |
|
|
|
SYSCALL_DEFINE1(shmdt, char __user *, shmaddr) |
|
{ |
|
return ksys_shmdt(shmaddr); |
|
} |
|
|
|
#ifdef CONFIG_PROC_FS |
|
static int sysvipc_shm_proc_show(struct seq_file *s, void *it) |
|
{ |
|
struct pid_namespace *pid_ns = ipc_seq_pid_ns(s); |
|
struct user_namespace *user_ns = seq_user_ns(s); |
|
struct kern_ipc_perm *ipcp = it; |
|
struct shmid_kernel *shp; |
|
unsigned long rss = 0, swp = 0; |
|
|
|
shp = container_of(ipcp, struct shmid_kernel, shm_perm); |
|
shm_add_rss_swap(shp, &rss, &swp); |
|
|
|
#if BITS_PER_LONG <= 32 |
|
#define SIZE_SPEC "%10lu" |
|
#else |
|
#define SIZE_SPEC "%21lu" |
|
#endif |
|
|
|
seq_printf(s, |
|
"%10d %10d %4o " SIZE_SPEC " %5u %5u " |
|
"%5lu %5u %5u %5u %5u %10llu %10llu %10llu " |
|
SIZE_SPEC " " SIZE_SPEC "\n", |
|
shp->shm_perm.key, |
|
shp->shm_perm.id, |
|
shp->shm_perm.mode, |
|
shp->shm_segsz, |
|
pid_nr_ns(shp->shm_cprid, pid_ns), |
|
pid_nr_ns(shp->shm_lprid, pid_ns), |
|
shp->shm_nattch, |
|
from_kuid_munged(user_ns, shp->shm_perm.uid), |
|
from_kgid_munged(user_ns, shp->shm_perm.gid), |
|
from_kuid_munged(user_ns, shp->shm_perm.cuid), |
|
from_kgid_munged(user_ns, shp->shm_perm.cgid), |
|
shp->shm_atim, |
|
shp->shm_dtim, |
|
shp->shm_ctim, |
|
rss * PAGE_SIZE, |
|
swp * PAGE_SIZE); |
|
|
|
return 0; |
|
} |
|
#endif
|
|
|