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ipc/shm.c
25.1 KB
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/* * linux/ipc/shm.c * Copyright (C) 1992, 1993 Krishna Balasubramanian * Many improvements/fixes by Bruno Haible. * Replaced `struct shm_desc' by `struct vm_area_struct', July 1994. * Fixed the shm swap deallocation (shm_unuse()), August 1998 Andrea Arcangeli. * * /proc/sysvipc/shm support (c) 1999 Dragos Acostachioaie <dragos@iname.com> * BIGMEM support, Andrea Arcangeli <andrea@suse.de> * SMP thread shm, Jean-Luc Boyard <jean-luc.boyard@siemens.fr> * HIGHMEM support, Ingo Molnar <mingo@redhat.com> * Make shmmax, shmall, shmmni sysctl'able, Christoph Rohland <cr@sap.com> * Shared /dev/zero support, Kanoj Sarcar <kanoj@sgi.com> * Move the mm functionality over to mm/shmem.c, Christoph Rohland <cr@sap.com> * |
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* support for audit of ipc object properties and permission changes * Dustin Kirkland <dustin.kirkland@us.ibm.com> |
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* * namespaces support * OpenVZ, SWsoft Inc. * Pavel Emelianov <xemul@openvz.org> |
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*/ |
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#include <linux/slab.h> #include <linux/mm.h> #include <linux/hugetlb.h> #include <linux/shm.h> #include <linux/init.h> #include <linux/file.h> #include <linux/mman.h> |
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#include <linux/shmem_fs.h> #include <linux/security.h> #include <linux/syscalls.h> #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 <asm/uaccess.h> #include "util.h" |
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struct shm_file_data { int id; struct ipc_namespace *ns; struct file *file; const struct vm_operations_struct *vm_ops; }; #define shm_file_data(file) (*((struct shm_file_data **)&(file)->private_data)) |
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static const struct file_operations shm_file_operations; |
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static struct vm_operations_struct shm_vm_ops; |
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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) \ 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); 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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void shm_init_ns(struct ipc_namespace *ns) |
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{ |
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ns->shm_ctlmax = SHMMAX; ns->shm_ctlall = SHMALL; ns->shm_ctlmni = SHMMNI; ns->shm_tot = 0; |
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ipc_init_ids(&ns->ids[IPC_SHM_IDS]); |
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} |
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/* |
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* Called with shm_ids.rw_mutex (writer) and the shp structure locked. * Only shm_ids.rw_mutex 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; shp = container_of(ipcp, struct shmid_kernel, shm_perm); |
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if (shp->shm_nattch){ shp->shm_perm.mode |= SHM_DEST; /* Do not find it any more */ shp->shm_perm.key = IPC_PRIVATE; shm_unlock(shp); } else shm_destroy(ns, shp); } |
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#ifdef CONFIG_IPC_NS |
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void shm_exit_ns(struct ipc_namespace *ns) { |
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free_ipcs(ns, &shm_ids(ns), do_shm_rmid); |
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} |
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#endif |
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void __init shm_init (void) { |
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shm_init_ns(&init_ipc_ns); |
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ipc_init_proc_interface("sysvipc/shm", " key shmid perms size cpid lpid nattch uid gid cuid cgid atime dtime ctime ", |
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IPC_SHM_IDS, sysvipc_shm_proc_show); |
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} |
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/* |
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* shm_lock_(check_) routines are called in the paths where the rw_mutex |
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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 = ipc_lock(&shm_ids(ns), id); |
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if (IS_ERR(ipcp)) return (struct shmid_kernel *)ipcp; |
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return container_of(ipcp, struct shmid_kernel, shm_perm); |
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} static inline struct shmid_kernel *shm_lock_check(struct ipc_namespace *ns, int id) { |
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struct kern_ipc_perm *ipcp = ipc_lock_check(&shm_ids(ns), id); |
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if (IS_ERR(ipcp)) return (struct shmid_kernel *)ipcp; |
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return container_of(ipcp, struct shmid_kernel, shm_perm); |
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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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ipc_rmid(&shm_ids(ns), &s->shm_perm); |
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} |
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|
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/* This is called by fork, once for every shm attach. */ static void shm_open(struct vm_area_struct *vma) |
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{ |
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struct file *file = vma->vm_file; 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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BUG_ON(IS_ERR(shp)); |
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shp->shm_atim = get_seconds(); |
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shp->shm_lprid = task_tgid_vnr(current); |
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shp->shm_nattch++; shm_unlock(shp); } |
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/* * shm_destroy - free the struct shmid_kernel * |
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* @ns: namespace |
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* @shp: struct to free * |
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* It has to be called with shp and shm_ids.rw_mutex (writer) locked, |
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* but returns with shp unlocked and freed. */ |
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static void shm_destroy(struct ipc_namespace *ns, struct shmid_kernel *shp) |
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{ |
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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); if (!is_file_hugepages(shp->shm_file)) shmem_lock(shp->shm_file, 0, shp->mlock_user); else |
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user_shm_unlock(shp->shm_file->f_path.dentry->d_inode->i_size, |
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shp->mlock_user); fput (shp->shm_file); security_shm_free(shp); ipc_rcu_putref(shp); } /* |
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* remove the attach descriptor vma. |
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* free memory for segment if it is marked destroyed. * The descriptor has already been removed from the current->mm->mmap list * and will later be kfree()d. */ |
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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; 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).rw_mutex); |
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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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BUG_ON(IS_ERR(shp)); |
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shp->shm_lprid = task_tgid_vnr(current); |
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shp->shm_dtim = get_seconds(); shp->shm_nattch--; if(shp->shm_nattch == 0 && |
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shp->shm_perm.mode & SHM_DEST) |
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shm_destroy(ns, shp); |
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else shm_unlock(shp); |
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up_write(&shm_ids(ns).rw_mutex); |
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} |
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static int shm_fault(struct vm_area_struct *vma, struct vm_fault *vmf) |
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{ struct file *file = vma->vm_file; struct shm_file_data *sfd = shm_file_data(file); |
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return sfd->vm_ops->fault(vma, vmf); |
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} #ifdef CONFIG_NUMA |
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static int shm_set_policy(struct vm_area_struct *vma, struct mempolicy *new) |
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{ struct file *file = vma->vm_file; struct shm_file_data *sfd = shm_file_data(file); int err = 0; if (sfd->vm_ops->set_policy) err = sfd->vm_ops->set_policy(vma, new); return err; } |
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static struct mempolicy *shm_get_policy(struct vm_area_struct *vma, unsigned long addr) |
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{ struct file *file = vma->vm_file; struct shm_file_data *sfd = shm_file_data(file); struct mempolicy *pol = NULL; if (sfd->vm_ops->get_policy) pol = sfd->vm_ops->get_policy(vma, addr); |
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else if (vma->vm_policy) |
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pol = vma->vm_policy; |
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return pol; } #endif |
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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); |
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int ret; |
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ret = sfd->file->f_op->mmap(sfd->file, vma); if (ret != 0) return ret; sfd->vm_ops = vma->vm_ops; |
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#ifdef CONFIG_MMU |
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BUG_ON(!sfd->vm_ops->fault); |
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#endif |
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vma->vm_ops = &shm_vm_ops; shm_open(vma); |
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return ret; |
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} |
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static int shm_release(struct inode *ino, struct file *file) { |
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struct shm_file_data *sfd = shm_file_data(file); |
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put_ipc_ns(sfd->ns); shm_file_data(file) = NULL; kfree(sfd); |
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return 0; } |
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static int shm_fsync(struct file *file, struct dentry *dentry, int datasync) { int (*fsync) (struct file *, struct dentry *, int datasync); struct shm_file_data *sfd = shm_file_data(file); int ret = -EINVAL; fsync = sfd->file->f_op->fsync; if (fsync) ret = fsync(sfd->file, sfd->file->f_path.dentry, datasync); return ret; } |
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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); |
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return get_unmapped_area(sfd->file, addr, len, pgoff, flags); } int is_file_shm_hugepages(struct file *file) { int ret = 0; if (file->f_op == &shm_file_operations) { struct shm_file_data *sfd; sfd = shm_file_data(file); ret = is_file_hugepages(sfd->file); } return ret; |
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} |
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static const struct file_operations shm_file_operations = { |
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.mmap = shm_mmap, |
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.fsync = shm_fsync, |
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.release = shm_release, |
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.get_unmapped_area = shm_get_unmapped_area, |
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}; static 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 */ |
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.fault = shm_fault, |
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#if defined(CONFIG_NUMA) .set_policy = shm_set_policy, .get_policy = shm_get_policy, |
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#endif }; |
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/** * newseg - Create a new shared memory segment * @ns: namespace * @params: ptr to the structure that contains key, size and shmflg * |
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* Called with shm_ids.rw_mutex held as a writer. |
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*/ |
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static int newseg(struct ipc_namespace *ns, struct ipc_params *params) |
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{ |
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key_t key = params->key; int shmflg = params->flg; size_t size = params->u.size; |
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int error; struct shmid_kernel *shp; int numpages = (size + PAGE_SIZE -1) >> PAGE_SHIFT; struct file * file; char name[13]; int id; |
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if (size < SHMMIN || size > ns->shm_ctlmax) |
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return -EINVAL; |
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if (ns->shm_tot + numpages > ns->shm_ctlall) |
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return -ENOSPC; shp = ipc_rcu_alloc(sizeof(*shp)); if (!shp) return -ENOMEM; shp->shm_perm.key = key; |
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shp->shm_perm.mode = (shmflg & S_IRWXUGO); |
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shp->mlock_user = NULL; shp->shm_perm.security = NULL; error = security_shm_alloc(shp); if (error) { ipc_rcu_putref(shp); return error; } |
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sprintf (name, "SYSV%08x", key); |
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if (shmflg & SHM_HUGETLB) { |
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/* hugetlb_file_setup takes care of mlock user accounting */ file = hugetlb_file_setup(name, size); |
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shp->mlock_user = current->user; } else { |
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int acctflag = VM_ACCOUNT; /* * Do not allow no accounting for OVERCOMMIT_NEVER, even * if it's asked for. */ if ((shmflg & SHM_NORESERVE) && sysctl_overcommit_memory != OVERCOMMIT_NEVER) acctflag = 0; |
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file = shmem_file_setup(name, size, acctflag); |
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} error = PTR_ERR(file); if (IS_ERR(file)) goto no_file; |
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id = ipc_addid(&shm_ids(ns), &shp->shm_perm, ns->shm_ctlmni); |
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if (id < 0) { error = id; |
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goto no_id; |
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} |
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shp->shm_cprid = task_tgid_vnr(current); |
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shp->shm_lprid = 0; shp->shm_atim = shp->shm_dtim = 0; shp->shm_ctim = get_seconds(); shp->shm_segsz = size; shp->shm_nattch = 0; |
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shp->shm_file = file; |
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/* * shmid gets reported as "inode#" in /proc/pid/maps. * proc-ps tools use this. Changing this will break them. */ |
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file->f_dentry->d_inode->i_ino = shp->shm_perm.id; |
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ns->shm_tot += numpages; |
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error = shp->shm_perm.id; |
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shm_unlock(shp); |
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return error; |
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no_id: fput(file); no_file: security_shm_free(shp); ipc_rcu_putref(shp); return error; } |
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/* |
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* Called with shm_ids.rw_mutex and ipcp locked. |
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*/ |
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static inline int shm_security(struct kern_ipc_perm *ipcp, int shmflg) |
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{ |
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struct shmid_kernel *shp; shp = container_of(ipcp, struct shmid_kernel, shm_perm); return security_shm_associate(shp, shmflg); |
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} |
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/* |
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* Called with shm_ids.rw_mutex and ipcp locked. |
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*/ |
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static inline int shm_more_checks(struct kern_ipc_perm *ipcp, struct ipc_params *params) |
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{ |
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struct shmid_kernel *shp; shp = container_of(ipcp, struct shmid_kernel, shm_perm); if (shp->shm_segsz < params->u.size) |
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return -EINVAL; return 0; } |
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asmlinkage long sys_shmget (key_t key, size_t size, int shmflg) { |
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struct ipc_namespace *ns; |
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struct ipc_ops shm_ops; struct ipc_params shm_params; |
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ns = current->nsproxy->ipc_ns; |
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shm_ops.getnew = newseg; shm_ops.associate = shm_security; shm_ops.more_checks = shm_more_checks; |
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shm_params.key = key; shm_params.flg = shmflg; shm_params.u.size = size; |
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return ipcget(ns, &shm_ids(ns), &shm_ops, &shm_params); |
1da177e4c
|
427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 |
} 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; 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; } } |
016d7132f
|
453 454 |
static inline unsigned long copy_shmid_from_user(struct shmid64_ds *out, void __user *buf, int version) |
1da177e4c
|
455 456 457 |
{ switch(version) { case IPC_64: |
016d7132f
|
458 |
if (copy_from_user(out, buf, sizeof(*out))) |
1da177e4c
|
459 |
return -EFAULT; |
1da177e4c
|
460 |
return 0; |
1da177e4c
|
461 462 463 464 465 466 |
case IPC_OLD: { struct shmid_ds tbuf_old; if (copy_from_user(&tbuf_old, buf, sizeof(tbuf_old))) return -EFAULT; |
016d7132f
|
467 468 469 |
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; |
1da177e4c
|
470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 |
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; } } |
f4566f048
|
503 |
/* |
3e148c799
|
504 |
* Called with shm_ids.rw_mutex held as a reader |
f4566f048
|
505 |
*/ |
4e9823111
|
506 507 |
static void shm_get_stat(struct ipc_namespace *ns, unsigned long *rss, unsigned long *swp) |
1da177e4c
|
508 |
{ |
7ca7e564e
|
509 510 |
int next_id; int total, in_use; |
1da177e4c
|
511 512 513 |
*rss = 0; *swp = 0; |
7ca7e564e
|
514 515 516 |
in_use = shm_ids(ns).in_use; for (total = 0, next_id = 0; total < in_use; next_id++) { |
1da177e4c
|
517 518 |
struct shmid_kernel *shp; struct inode *inode; |
637c36634
|
519 |
shp = idr_find(&shm_ids(ns).ipcs_idr, next_id); |
7ca7e564e
|
520 |
if (shp == NULL) |
1da177e4c
|
521 |
continue; |
6d63079ad
|
522 |
inode = shp->shm_file->f_path.dentry->d_inode; |
1da177e4c
|
523 524 525 |
if (is_file_hugepages(shp->shm_file)) { struct address_space *mapping = inode->i_mapping; |
a55164389
|
526 527 |
struct hstate *h = hstate_file(shp->shm_file); *rss += pages_per_huge_page(h) * mapping->nrpages; |
1da177e4c
|
528 529 530 531 532 533 534 |
} else { struct shmem_inode_info *info = SHMEM_I(inode); spin_lock(&info->lock); *rss += inode->i_mapping->nrpages; *swp += info->swapped; spin_unlock(&info->lock); } |
7ca7e564e
|
535 536 |
total++; |
1da177e4c
|
537 538 |
} } |
8d4cc8b5c
|
539 540 541 542 543 544 545 |
/* * This function handles some shmctl commands which require the rw_mutex * to be held in write mode. * NOTE: no locks must be held, the rw_mutex is taken inside this function. */ static int shmctl_down(struct ipc_namespace *ns, int shmid, int cmd, struct shmid_ds __user *buf, int version) |
1da177e4c
|
546 |
{ |
8d4cc8b5c
|
547 |
struct kern_ipc_perm *ipcp; |
016d7132f
|
548 |
struct shmid64_ds shmid64; |
1da177e4c
|
549 |
struct shmid_kernel *shp; |
8d4cc8b5c
|
550 551 552 |
int err; if (cmd == IPC_SET) { |
016d7132f
|
553 |
if (copy_shmid_from_user(&shmid64, buf, version)) |
8d4cc8b5c
|
554 555 |
return -EFAULT; } |
a5f75e7f2
|
556 557 558 |
ipcp = ipcctl_pre_down(&shm_ids(ns), shmid, cmd, &shmid64.shm_perm, 0); if (IS_ERR(ipcp)) return PTR_ERR(ipcp); |
8d4cc8b5c
|
559 |
|
a5f75e7f2
|
560 |
shp = container_of(ipcp, struct shmid_kernel, shm_perm); |
8d4cc8b5c
|
561 562 563 564 565 566 567 568 569 |
err = security_shm_shmctl(shp, cmd); if (err) goto out_unlock; switch (cmd) { case IPC_RMID: do_shm_rmid(ns, ipcp); goto out_up; case IPC_SET: |
8f4a3809c
|
570 |
ipc_update_perm(&shmid64.shm_perm, ipcp); |
8d4cc8b5c
|
571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 |
shp->shm_ctim = get_seconds(); break; default: err = -EINVAL; } out_unlock: shm_unlock(shp); out_up: up_write(&shm_ids(ns).rw_mutex); return err; } asmlinkage long sys_shmctl(int shmid, int cmd, struct shmid_ds __user *buf) { struct shmid_kernel *shp; |
1da177e4c
|
586 |
int err, version; |
4e9823111
|
587 |
struct ipc_namespace *ns; |
1da177e4c
|
588 589 590 591 592 593 594 |
if (cmd < 0 || shmid < 0) { err = -EINVAL; goto out; } version = ipc_parse_version(&cmd); |
4e9823111
|
595 |
ns = current->nsproxy->ipc_ns; |
1da177e4c
|
596 597 598 599 600 601 602 603 604 605 606 |
switch (cmd) { /* replace with proc interface ? */ case IPC_INFO: { struct shminfo64 shminfo; err = security_shm_shmctl(NULL, cmd); if (err) return err; memset(&shminfo,0,sizeof(shminfo)); |
4e9823111
|
607 608 609 |
shminfo.shmmni = shminfo.shmseg = ns->shm_ctlmni; shminfo.shmmax = ns->shm_ctlmax; shminfo.shmall = ns->shm_ctlall; |
1da177e4c
|
610 611 612 613 |
shminfo.shmmin = SHMMIN; if(copy_shminfo_to_user (buf, &shminfo, version)) return -EFAULT; |
f4566f048
|
614 |
|
3e148c799
|
615 |
down_read(&shm_ids(ns).rw_mutex); |
7ca7e564e
|
616 |
err = ipc_get_maxid(&shm_ids(ns)); |
3e148c799
|
617 |
up_read(&shm_ids(ns).rw_mutex); |
f4566f048
|
618 |
|
1da177e4c
|
619 620 621 622 623 624 625 626 627 628 629 630 631 |
if(err<0) err = 0; goto out; } case SHM_INFO: { struct shm_info shm_info; err = security_shm_shmctl(NULL, cmd); if (err) return err; memset(&shm_info,0,sizeof(shm_info)); |
3e148c799
|
632 |
down_read(&shm_ids(ns).rw_mutex); |
4e9823111
|
633 634 635 |
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; |
1da177e4c
|
636 637 |
shm_info.swap_attempts = 0; shm_info.swap_successes = 0; |
7ca7e564e
|
638 |
err = ipc_get_maxid(&shm_ids(ns)); |
3e148c799
|
639 |
up_read(&shm_ids(ns).rw_mutex); |
1da177e4c
|
640 641 642 643 644 645 646 647 648 649 650 651 652 |
if(copy_to_user (buf, &shm_info, sizeof(shm_info))) { err = -EFAULT; goto out; } err = err < 0 ? 0 : err; goto out; } case SHM_STAT: case IPC_STAT: { struct shmid64_ds tbuf; int result; |
023a53557
|
653 654 655 |
if (!buf) { err = -EFAULT; |
1da177e4c
|
656 |
goto out; |
023a53557
|
657 658 659 660 661 662 663 664 |
} if (cmd == SHM_STAT) { shp = shm_lock(ns, shmid); if (IS_ERR(shp)) { err = PTR_ERR(shp); goto out; } |
7ca7e564e
|
665 |
result = shp->shm_perm.id; |
1da177e4c
|
666 |
} else { |
023a53557
|
667 668 669 670 671 |
shp = shm_lock_check(ns, shmid); if (IS_ERR(shp)) { err = PTR_ERR(shp); goto out; } |
1da177e4c
|
672 673 674 675 676 677 678 679 |
result = 0; } err=-EACCES; if (ipcperms (&shp->shm_perm, S_IRUGO)) goto out_unlock; err = security_shm_shmctl(shp, cmd); if (err) goto out_unlock; |
023a53557
|
680 |
memset(&tbuf, 0, sizeof(tbuf)); |
1da177e4c
|
681 682 683 684 685 686 687 |
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; tbuf.shm_cpid = shp->shm_cprid; tbuf.shm_lpid = shp->shm_lprid; |
bc56bba8f
|
688 |
tbuf.shm_nattch = shp->shm_nattch; |
1da177e4c
|
689 690 691 692 693 694 695 696 697 698 |
shm_unlock(shp); if(copy_shmid_to_user (buf, &tbuf, version)) err = -EFAULT; else err = result; goto out; } case SHM_LOCK: case SHM_UNLOCK: { |
023a53557
|
699 700 701 |
shp = shm_lock_check(ns, shmid); if (IS_ERR(shp)) { err = PTR_ERR(shp); |
1da177e4c
|
702 703 |
goto out; } |
1da177e4c
|
704 |
|
073115d6b
|
705 706 707 |
err = audit_ipc_obj(&(shp->shm_perm)); if (err) goto out_unlock; |
1da177e4c
|
708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 |
if (!capable(CAP_IPC_LOCK)) { err = -EPERM; if (current->euid != shp->shm_perm.uid && current->euid != shp->shm_perm.cuid) goto out_unlock; if (cmd == SHM_LOCK && !current->signal->rlim[RLIMIT_MEMLOCK].rlim_cur) goto out_unlock; } err = security_shm_shmctl(shp, cmd); if (err) goto out_unlock; if(cmd==SHM_LOCK) { struct user_struct * user = current->user; if (!is_file_hugepages(shp->shm_file)) { err = shmem_lock(shp->shm_file, 1, user); |
7be77e20d
|
726 |
if (!err && !(shp->shm_perm.mode & SHM_LOCKED)){ |
b33291c0b
|
727 |
shp->shm_perm.mode |= SHM_LOCKED; |
1da177e4c
|
728 729 730 731 732 |
shp->mlock_user = user; } } } else if (!is_file_hugepages(shp->shm_file)) { shmem_lock(shp->shm_file, 0, shp->mlock_user); |
b33291c0b
|
733 |
shp->shm_perm.mode &= ~SHM_LOCKED; |
1da177e4c
|
734 735 736 737 738 739 |
shp->mlock_user = NULL; } shm_unlock(shp); goto out; } case IPC_RMID: |
1da177e4c
|
740 |
case IPC_SET: |
8d4cc8b5c
|
741 742 |
err = shmctl_down(ns, shmid, cmd, buf, version); return err; |
1da177e4c
|
743 |
default: |
8d4cc8b5c
|
744 |
return -EINVAL; |
1da177e4c
|
745 |
} |
1da177e4c
|
746 747 748 749 750 751 752 753 754 755 756 757 758 759 760 761 762 763 764 765 766 767 |
out_unlock: shm_unlock(shp); out: return err; } /* * 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) { struct shmid_kernel *shp; unsigned long addr; unsigned long size; struct file * file; int err; unsigned long flags; unsigned long prot; |
1da177e4c
|
768 |
int acc_mode; |
bc56bba8f
|
769 |
unsigned long user_addr; |
4e9823111
|
770 |
struct ipc_namespace *ns; |
bc56bba8f
|
771 772 773 |
struct shm_file_data *sfd; struct path path; mode_t f_mode; |
1da177e4c
|
774 |
|
bc56bba8f
|
775 776 |
err = -EINVAL; if (shmid < 0) |
1da177e4c
|
777 |
goto out; |
bc56bba8f
|
778 |
else if ((addr = (ulong)shmaddr)) { |
1da177e4c
|
779 780 781 782 783 784 785 |
if (addr & (SHMLBA-1)) { if (shmflg & SHM_RND) addr &= ~(SHMLBA-1); /* round down */ else #ifndef __ARCH_FORCE_SHMLBA if (addr & ~PAGE_MASK) #endif |
bc56bba8f
|
786 |
goto out; |
1da177e4c
|
787 788 789 790 |
} flags = MAP_SHARED | MAP_FIXED; } else { if ((shmflg & SHM_REMAP)) |
bc56bba8f
|
791 |
goto out; |
1da177e4c
|
792 793 794 795 796 797 |
flags = MAP_SHARED; } if (shmflg & SHM_RDONLY) { prot = PROT_READ; |
1da177e4c
|
798 |
acc_mode = S_IRUGO; |
bc56bba8f
|
799 |
f_mode = FMODE_READ; |
1da177e4c
|
800 801 |
} else { prot = PROT_READ | PROT_WRITE; |
1da177e4c
|
802 |
acc_mode = S_IRUGO | S_IWUGO; |
bc56bba8f
|
803 |
f_mode = FMODE_READ | FMODE_WRITE; |
1da177e4c
|
804 805 806 807 808 809 810 811 812 813 |
} 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... */ |
4e9823111
|
814 |
ns = current->nsproxy->ipc_ns; |
023a53557
|
815 816 817 |
shp = shm_lock_check(ns, shmid); if (IS_ERR(shp)) { err = PTR_ERR(shp); |
1da177e4c
|
818 |
goto out; |
023a53557
|
819 |
} |
bc56bba8f
|
820 821 822 823 |
err = -EACCES; if (ipcperms(&shp->shm_perm, acc_mode)) goto out_unlock; |
1da177e4c
|
824 825 |
err = security_shm_shmat(shp, shmaddr, shmflg); |
bc56bba8f
|
826 827 828 829 |
if (err) goto out_unlock; path.dentry = dget(shp->shm_file->f_path.dentry); |
ce8d2cdf3
|
830 |
path.mnt = shp->shm_file->f_path.mnt; |
1da177e4c
|
831 |
shp->shm_nattch++; |
bc56bba8f
|
832 |
size = i_size_read(path.dentry->d_inode); |
1da177e4c
|
833 |
shm_unlock(shp); |
bc56bba8f
|
834 835 836 |
err = -ENOMEM; sfd = kzalloc(sizeof(*sfd), GFP_KERNEL); if (!sfd) |
ce8d2cdf3
|
837 |
goto out_put_dentry; |
bc56bba8f
|
838 |
|
ce8d2cdf3
|
839 |
file = alloc_file(path.mnt, path.dentry, f_mode, &shm_file_operations); |
bc56bba8f
|
840 841 |
if (!file) goto out_free; |
bc56bba8f
|
842 |
file->private_data = sfd; |
bc56bba8f
|
843 |
file->f_mapping = shp->shm_file->f_mapping; |
7ca7e564e
|
844 |
sfd->id = shp->shm_perm.id; |
bc56bba8f
|
845 846 847 |
sfd->ns = get_ipc_ns(ns); sfd->file = shp->shm_file; sfd->vm_ops = NULL; |
1da177e4c
|
848 849 |
down_write(¤t->mm->mmap_sem); if (addr && !(shmflg & SHM_REMAP)) { |
bc56bba8f
|
850 |
err = -EINVAL; |
1da177e4c
|
851 852 853 854 855 856 857 858 859 860 861 |
if (find_vma_intersection(current->mm, addr, addr + size)) goto invalid; /* * If shm segment goes below stack, make sure there is some * space left for the stack to grow (at least 4 pages). */ if (addr < current->mm->start_stack && addr > current->mm->start_stack - size - PAGE_SIZE * 5) goto invalid; } |
bc56bba8f
|
862 863 864 865 866 |
user_addr = do_mmap (file, addr, size, prot, flags, 0); *raddr = user_addr; err = 0; if (IS_ERR_VALUE(user_addr)) err = (long)user_addr; |
1da177e4c
|
867 868 |
invalid: up_write(¤t->mm->mmap_sem); |
bc56bba8f
|
869 870 871 |
fput(file); out_nattch: |
3e148c799
|
872 |
down_write(&shm_ids(ns).rw_mutex); |
00c2bf85d
|
873 |
shp = shm_lock(ns, shmid); |
023a53557
|
874 |
BUG_ON(IS_ERR(shp)); |
1da177e4c
|
875 876 |
shp->shm_nattch--; if(shp->shm_nattch == 0 && |
b33291c0b
|
877 |
shp->shm_perm.mode & SHM_DEST) |
4e9823111
|
878 |
shm_destroy(ns, shp); |
1da177e4c
|
879 880 |
else shm_unlock(shp); |
3e148c799
|
881 |
up_write(&shm_ids(ns).rw_mutex); |
1da177e4c
|
882 |
|
1da177e4c
|
883 884 |
out: return err; |
bc56bba8f
|
885 886 887 888 889 890 891 |
out_unlock: shm_unlock(shp); goto out; out_free: kfree(sfd); |
ce8d2cdf3
|
892 |
out_put_dentry: |
bc56bba8f
|
893 |
dput(path.dentry); |
bc56bba8f
|
894 |
goto out_nattch; |
1da177e4c
|
895 |
} |
7d87e14c2
|
896 897 898 899 900 901 902 903 904 905 906 |
asmlinkage long sys_shmat(int shmid, char __user *shmaddr, int shmflg) { unsigned long ret; long err; err = do_shmat(shmid, shmaddr, shmflg, &ret); if (err) return err; force_successful_syscall_return(); return (long)ret; } |
1da177e4c
|
907 908 909 910 911 912 913 914 915 916 917 |
/* * detach and kill segment if marked destroyed. * The work is done in shm_close. */ asmlinkage long sys_shmdt(char __user *shmaddr) { struct mm_struct *mm = current->mm; struct vm_area_struct *vma, *next; unsigned long addr = (unsigned long)shmaddr; loff_t size = 0; int retval = -EINVAL; |
df1e2fb54
|
918 919 |
if (addr & ~PAGE_MASK) return retval; |
1da177e4c
|
920 921 922 923 924 925 926 927 928 929 930 931 932 933 934 935 936 937 938 939 940 941 942 943 944 945 946 947 948 949 950 951 |
down_write(&mm->mmap_sem); /* * 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. * 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); 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. */ |
bc56bba8f
|
952 |
if ((vma->vm_ops == &shm_vm_ops) && |
1da177e4c
|
953 |
(vma->vm_start - addr)/PAGE_SIZE == vma->vm_pgoff) { |
6d63079ad
|
954 |
size = vma->vm_file->f_path.dentry->d_inode->i_size; |
1da177e4c
|
955 956 957 958 959 960 961 962 963 964 965 966 967 968 969 970 971 972 973 |
do_munmap(mm, vma->vm_start, vma->vm_end - vma->vm_start); /* * 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 comparisions vs. equal-width types. */ |
8e36709d8
|
974 |
size = PAGE_ALIGN(size); |
1da177e4c
|
975 976 977 978 |
while (vma && (loff_t)(vma->vm_end - addr) <= size) { next = vma->vm_next; /* finding a matching vma now does not alter retval */ |
bc56bba8f
|
979 |
if ((vma->vm_ops == &shm_vm_ops) && |
1da177e4c
|
980 981 982 983 984 985 986 987 988 989 990 |
(vma->vm_start - addr)/PAGE_SIZE == vma->vm_pgoff) do_munmap(mm, vma->vm_start, vma->vm_end - vma->vm_start); vma = next; } up_write(&mm->mmap_sem); return retval; } #ifdef CONFIG_PROC_FS |
19b4946ca
|
991 |
static int sysvipc_shm_proc_show(struct seq_file *s, void *it) |
1da177e4c
|
992 |
{ |
19b4946ca
|
993 |
struct shmid_kernel *shp = it; |
1da177e4c
|
994 |
|
6c826818f
|
995 996 997 998 999 |
#if BITS_PER_LONG <= 32 #define SIZE_SPEC "%10lu" #else #define SIZE_SPEC "%21lu" #endif |
1da177e4c
|
1000 |
|
6c826818f
|
1001 1002 1003 1004 |
return seq_printf(s, "%10d %10d %4o " SIZE_SPEC " %5u %5u " "%5lu %5u %5u %5u %5u %10lu %10lu %10lu ", |
19b4946ca
|
1005 |
shp->shm_perm.key, |
7ca7e564e
|
1006 |
shp->shm_perm.id, |
b33291c0b
|
1007 |
shp->shm_perm.mode, |
19b4946ca
|
1008 1009 1010 |
shp->shm_segsz, shp->shm_cprid, shp->shm_lprid, |
bc56bba8f
|
1011 |
shp->shm_nattch, |
19b4946ca
|
1012 1013 1014 1015 1016 1017 1018 |
shp->shm_perm.uid, shp->shm_perm.gid, shp->shm_perm.cuid, shp->shm_perm.cgid, shp->shm_atim, shp->shm_dtim, shp->shm_ctim); |
1da177e4c
|
1019 1020 |
} #endif |