![Al Viro](/assets/img/avatar_default.png)
... we should call mm ->get_unmapped_area() instead and let our caller do the final checks. Acked-by: David S. Miller <davem@davemloft.net> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
1101 lines
26 KiB
C
1101 lines
26 KiB
C
/*
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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 <dragos@iname.com>
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* BIGMEM support, Andrea Arcangeli <andrea@suse.de>
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* SMP thread shm, Jean-Luc Boyard <jean-luc.boyard@siemens.fr>
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* HIGHMEM support, Ingo Molnar <mingo@redhat.com>
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* Make shmmax, shmall, shmmni sysctl'able, Christoph Rohland <cr@sap.com>
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* Shared /dev/zero support, Kanoj Sarcar <kanoj@sgi.com>
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* Move the mm functionality over to mm/shmem.c, Christoph Rohland <cr@sap.com>
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*
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* support for audit of ipc object properties and permission changes
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* Dustin Kirkland <dustin.kirkland@us.ibm.com>
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*
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* namespaces support
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* OpenVZ, SWsoft Inc.
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* Pavel Emelianov <xemul@openvz.org>
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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/ima.h>
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#include <asm/uaccess.h>
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#include "util.h"
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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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#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 const struct vm_operations_struct shm_vm_ops;
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#define shm_ids(ns) ((ns)->ids[IPC_SHM_IDS])
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#define shm_unlock(shp) \
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ipc_unlock(&(shp)->shm_perm)
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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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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_tot = 0;
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ipc_init_ids(&shm_ids(ns));
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}
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/*
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* Called with shm_ids.rw_mutex (writer) and the shp structure locked.
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* 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;
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shp = container_of(ipcp, struct shmid_kernel, shm_perm);
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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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shp->shm_perm.key = IPC_PRIVATE;
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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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#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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}
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#endif
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void __init shm_init (void)
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{
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shm_init_ns(&init_ipc_ns);
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ipc_init_proc_interface("sysvipc/shm",
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" key shmid perms size cpid lpid nattch uid gid cuid cgid atime dtime ctime\n",
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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))
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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 struct shmid_kernel *shm_lock_check(struct ipc_namespace *ns,
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int id)
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{
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struct kern_ipc_perm *ipcp = ipc_lock_check(&shm_ids(ns), id);
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if (IS_ERR(ipcp))
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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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/* 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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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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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++;
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shm_unlock(shp);
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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.rw_mutex (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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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(shp->shm_file))
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shmem_lock(shp->shm_file, 0, shp->mlock_user);
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else if (shp->mlock_user)
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user_shm_unlock(shp->shm_file->f_path.dentry->d_inode->i_size,
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shp->mlock_user);
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fput (shp->shm_file);
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security_shm_free(shp);
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ipc_rcu_putref(shp);
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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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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();
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shp->shm_nattch--;
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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
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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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{
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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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return sfd->vm_ops->fault(vma, vmf);
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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)
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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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int err = 0;
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if (sfd->vm_ops->set_policy)
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err = sfd->vm_ops->set_policy(vma, new);
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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)
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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 mempolicy *pol = NULL;
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if (sfd->vm_ops->get_policy)
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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;
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}
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#endif
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static int shm_mmap(struct file * file, struct vm_area_struct * vma)
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{
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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);
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if (ret != 0)
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return ret;
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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;
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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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{
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struct shm_file_data *sfd = shm_file_data(file);
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put_ipc_ns(sfd->ns);
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shm_file_data(file) = NULL;
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kfree(sfd);
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return 0;
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}
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static int shm_fsync(struct file *file, struct dentry *dentry, int datasync)
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{
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int (*fsync) (struct file *, struct dentry *, int datasync);
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struct shm_file_data *sfd = shm_file_data(file);
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int ret = -EINVAL;
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fsync = sfd->file->f_op->fsync;
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if (fsync)
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ret = fsync(sfd->file, sfd->file->f_path.dentry, datasync);
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return ret;
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}
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static unsigned long shm_get_unmapped_area(struct file *file,
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unsigned long addr, unsigned long len, unsigned long pgoff,
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unsigned long flags)
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{
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struct shm_file_data *sfd = shm_file_data(file);
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return sfd->file->f_op->get_unmapped_area(sfd->file, addr, len,
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pgoff, flags);
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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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};
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static const struct file_operations shm_file_operations_huge = {
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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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};
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int is_file_shm_hugepages(struct file *file)
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{
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return file->f_op == &shm_file_operations_huge;
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}
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static const struct vm_operations_struct shm_vm_ops = {
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.open = shm_open, /* callback for a new vm-area open */
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.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)
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.set_policy = shm_set_policy,
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.get_policy = shm_get_policy,
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#endif
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};
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/**
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* newseg - Create a new shared memory segment
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* @ns: namespace
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* @params: ptr to the structure that contains key, size and shmflg
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*
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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;
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int shmflg = params->flg;
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size_t size = params->u.size;
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int error;
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struct shmid_kernel *shp;
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int numpages = (size + PAGE_SIZE -1) >> PAGE_SHIFT;
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struct file * file;
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char name[13];
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int id;
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int acctflag = 0;
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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;
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shp = ipc_rcu_alloc(sizeof(*shp));
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if (!shp)
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return -ENOMEM;
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shp->shm_perm.key = key;
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shp->shm_perm.mode = (shmflg & S_IRWXUGO);
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shp->mlock_user = NULL;
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shp->shm_perm.security = NULL;
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error = security_shm_alloc(shp);
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if (error) {
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ipc_rcu_putref(shp);
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return error;
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}
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sprintf (name, "SYSV%08x", key);
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if (shmflg & SHM_HUGETLB) {
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/* hugetlb_file_setup applies strict accounting */
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if (shmflg & SHM_NORESERVE)
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acctflag = VM_NORESERVE;
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file = hugetlb_file_setup(name, size, acctflag,
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&shp->mlock_user, HUGETLB_SHMFS_INODE);
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} else {
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/*
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* Do not allow no accounting for OVERCOMMIT_NEVER, even
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* if it's asked for.
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*/
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if ((shmflg & SHM_NORESERVE) &&
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sysctl_overcommit_memory != OVERCOMMIT_NEVER)
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acctflag = VM_NORESERVE;
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file = shmem_file_setup(name, size, acctflag);
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}
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error = PTR_ERR(file);
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if (IS_ERR(file))
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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) {
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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;
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shp->shm_atim = shp->shm_dtim = 0;
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shp->shm_ctim = get_seconds();
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shp->shm_segsz = size;
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shp->shm_nattch = 0;
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shp->shm_file = file;
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/*
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* shmid gets reported as "inode#" in /proc/pid/maps.
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* proc-ps tools use this. Changing this will break them.
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*/
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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:
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if (is_file_hugepages(file) && shp->mlock_user)
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user_shm_unlock(size, shp->mlock_user);
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fput(file);
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no_file:
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security_shm_free(shp);
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ipc_rcu_putref(shp);
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return error;
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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_security(struct kern_ipc_perm *ipcp, int shmflg)
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{
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struct shmid_kernel *shp;
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shp = container_of(ipcp, struct shmid_kernel, shm_perm);
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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,
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struct ipc_params *params)
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{
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struct shmid_kernel *shp;
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shp = container_of(ipcp, struct shmid_kernel, shm_perm);
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if (shp->shm_segsz < params->u.size)
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return -EINVAL;
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return 0;
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}
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SYSCALL_DEFINE3(shmget, key_t, key, size_t, size, int, shmflg)
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{
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struct ipc_namespace *ns;
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struct ipc_ops shm_ops;
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struct ipc_params shm_params;
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ns = current->nsproxy->ipc_ns;
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shm_ops.getnew = newseg;
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shm_ops.associate = shm_security;
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shm_ops.more_checks = shm_more_checks;
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shm_params.key = key;
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shm_params.flg = shmflg;
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shm_params.u.size = size;
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return ipcget(ns, &shm_ids(ns), &shm_ops, &shm_params);
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}
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static inline unsigned long copy_shmid_to_user(void __user *buf, struct shmid64_ds *in, int version)
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{
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switch(version) {
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case IPC_64:
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return copy_to_user(buf, in, sizeof(*in));
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case IPC_OLD:
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{
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struct shmid_ds out;
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|
|
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;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Called with shm_ids.rw_mutex 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;
|
|
struct inode *inode;
|
|
|
|
ipc = idr_find(&shm_ids(ns).ipcs_idr, next_id);
|
|
if (ipc == NULL)
|
|
continue;
|
|
shp = container_of(ipc, struct shmid_kernel, shm_perm);
|
|
|
|
inode = shp->shm_file->f_path.dentry->d_inode;
|
|
|
|
if (is_file_hugepages(shp->shm_file)) {
|
|
struct address_space *mapping = inode->i_mapping;
|
|
struct hstate *h = hstate_file(shp->shm_file);
|
|
*rss += pages_per_huge_page(h) * mapping->nrpages;
|
|
} else {
|
|
#ifdef CONFIG_SHMEM
|
|
struct shmem_inode_info *info = SHMEM_I(inode);
|
|
spin_lock(&info->lock);
|
|
*rss += inode->i_mapping->nrpages;
|
|
*swp += info->swapped;
|
|
spin_unlock(&info->lock);
|
|
#else
|
|
*rss += inode->i_mapping->nrpages;
|
|
#endif
|
|
}
|
|
|
|
total++;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* 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)
|
|
{
|
|
struct kern_ipc_perm *ipcp;
|
|
struct shmid64_ds shmid64;
|
|
struct shmid_kernel *shp;
|
|
int err;
|
|
|
|
if (cmd == IPC_SET) {
|
|
if (copy_shmid_from_user(&shmid64, buf, version))
|
|
return -EFAULT;
|
|
}
|
|
|
|
ipcp = ipcctl_pre_down(&shm_ids(ns), shmid, cmd, &shmid64.shm_perm, 0);
|
|
if (IS_ERR(ipcp))
|
|
return PTR_ERR(ipcp);
|
|
|
|
shp = container_of(ipcp, struct shmid_kernel, shm_perm);
|
|
|
|
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:
|
|
ipc_update_perm(&shmid64.shm_perm, ipcp);
|
|
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;
|
|
}
|
|
|
|
SYSCALL_DEFINE3(shmctl, int, shmid, int, cmd, struct shmid_ds __user *, buf)
|
|
{
|
|
struct shmid_kernel *shp;
|
|
int err, version;
|
|
struct ipc_namespace *ns;
|
|
|
|
if (cmd < 0 || shmid < 0) {
|
|
err = -EINVAL;
|
|
goto out;
|
|
}
|
|
|
|
version = ipc_parse_version(&cmd);
|
|
ns = current->nsproxy->ipc_ns;
|
|
|
|
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));
|
|
shminfo.shmmni = shminfo.shmseg = ns->shm_ctlmni;
|
|
shminfo.shmmax = ns->shm_ctlmax;
|
|
shminfo.shmall = ns->shm_ctlall;
|
|
|
|
shminfo.shmmin = SHMMIN;
|
|
if(copy_shminfo_to_user (buf, &shminfo, version))
|
|
return -EFAULT;
|
|
|
|
down_read(&shm_ids(ns).rw_mutex);
|
|
err = ipc_get_maxid(&shm_ids(ns));
|
|
up_read(&shm_ids(ns).rw_mutex);
|
|
|
|
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));
|
|
down_read(&shm_ids(ns).rw_mutex);
|
|
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_maxid(&shm_ids(ns));
|
|
up_read(&shm_ids(ns).rw_mutex);
|
|
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;
|
|
|
|
if (cmd == SHM_STAT) {
|
|
shp = shm_lock(ns, shmid);
|
|
if (IS_ERR(shp)) {
|
|
err = PTR_ERR(shp);
|
|
goto out;
|
|
}
|
|
result = shp->shm_perm.id;
|
|
} else {
|
|
shp = shm_lock_check(ns, shmid);
|
|
if (IS_ERR(shp)) {
|
|
err = PTR_ERR(shp);
|
|
goto out;
|
|
}
|
|
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;
|
|
memset(&tbuf, 0, sizeof(tbuf));
|
|
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;
|
|
tbuf.shm_nattch = shp->shm_nattch;
|
|
shm_unlock(shp);
|
|
if(copy_shmid_to_user (buf, &tbuf, version))
|
|
err = -EFAULT;
|
|
else
|
|
err = result;
|
|
goto out;
|
|
}
|
|
case SHM_LOCK:
|
|
case SHM_UNLOCK:
|
|
{
|
|
struct file *uninitialized_var(shm_file);
|
|
|
|
lru_add_drain_all(); /* drain pagevecs to lru lists */
|
|
|
|
shp = shm_lock_check(ns, shmid);
|
|
if (IS_ERR(shp)) {
|
|
err = PTR_ERR(shp);
|
|
goto out;
|
|
}
|
|
|
|
audit_ipc_obj(&(shp->shm_perm));
|
|
|
|
if (!capable(CAP_IPC_LOCK)) {
|
|
uid_t euid = current_euid();
|
|
err = -EPERM;
|
|
if (euid != shp->shm_perm.uid &&
|
|
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);
|
|
if (!err && !(shp->shm_perm.mode & SHM_LOCKED)){
|
|
shp->shm_perm.mode |= SHM_LOCKED;
|
|
shp->mlock_user = user;
|
|
}
|
|
}
|
|
} else if (!is_file_hugepages(shp->shm_file)) {
|
|
shmem_lock(shp->shm_file, 0, shp->mlock_user);
|
|
shp->shm_perm.mode &= ~SHM_LOCKED;
|
|
shp->mlock_user = NULL;
|
|
}
|
|
shm_unlock(shp);
|
|
goto out;
|
|
}
|
|
case IPC_RMID:
|
|
case IPC_SET:
|
|
err = shmctl_down(ns, shmid, cmd, buf, version);
|
|
return err;
|
|
default:
|
|
return -EINVAL;
|
|
}
|
|
|
|
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;
|
|
int acc_mode;
|
|
unsigned long user_addr;
|
|
struct ipc_namespace *ns;
|
|
struct shm_file_data *sfd;
|
|
struct path path;
|
|
fmode_t f_mode;
|
|
|
|
err = -EINVAL;
|
|
if (shmid < 0)
|
|
goto out;
|
|
else if ((addr = (ulong)shmaddr)) {
|
|
if (addr & (SHMLBA-1)) {
|
|
if (shmflg & SHM_RND)
|
|
addr &= ~(SHMLBA-1); /* round down */
|
|
else
|
|
#ifndef __ARCH_FORCE_SHMLBA
|
|
if (addr & ~PAGE_MASK)
|
|
#endif
|
|
goto out;
|
|
}
|
|
flags = MAP_SHARED | MAP_FIXED;
|
|
} else {
|
|
if ((shmflg & SHM_REMAP))
|
|
goto out;
|
|
|
|
flags = MAP_SHARED;
|
|
}
|
|
|
|
if (shmflg & SHM_RDONLY) {
|
|
prot = PROT_READ;
|
|
acc_mode = S_IRUGO;
|
|
f_mode = FMODE_READ;
|
|
} else {
|
|
prot = PROT_READ | PROT_WRITE;
|
|
acc_mode = S_IRUGO | S_IWUGO;
|
|
f_mode = FMODE_READ | FMODE_WRITE;
|
|
}
|
|
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;
|
|
shp = shm_lock_check(ns, shmid);
|
|
if (IS_ERR(shp)) {
|
|
err = PTR_ERR(shp);
|
|
goto out;
|
|
}
|
|
|
|
err = -EACCES;
|
|
if (ipcperms(&shp->shm_perm, acc_mode))
|
|
goto out_unlock;
|
|
|
|
err = security_shm_shmat(shp, shmaddr, shmflg);
|
|
if (err)
|
|
goto out_unlock;
|
|
|
|
path.dentry = dget(shp->shm_file->f_path.dentry);
|
|
path.mnt = shp->shm_file->f_path.mnt;
|
|
shp->shm_nattch++;
|
|
size = i_size_read(path.dentry->d_inode);
|
|
shm_unlock(shp);
|
|
|
|
err = -ENOMEM;
|
|
sfd = kzalloc(sizeof(*sfd), GFP_KERNEL);
|
|
if (!sfd)
|
|
goto out_put_dentry;
|
|
|
|
file = alloc_file(path.mnt, path.dentry, f_mode,
|
|
is_file_hugepages(shp->shm_file) ?
|
|
&shm_file_operations_huge :
|
|
&shm_file_operations);
|
|
if (!file)
|
|
goto out_free;
|
|
ima_counts_get(file);
|
|
|
|
file->private_data = sfd;
|
|
file->f_mapping = shp->shm_file->f_mapping;
|
|
sfd->id = shp->shm_perm.id;
|
|
sfd->ns = get_ipc_ns(ns);
|
|
sfd->file = shp->shm_file;
|
|
sfd->vm_ops = NULL;
|
|
|
|
down_write(¤t->mm->mmap_sem);
|
|
if (addr && !(shmflg & SHM_REMAP)) {
|
|
err = -EINVAL;
|
|
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;
|
|
}
|
|
|
|
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;
|
|
invalid:
|
|
up_write(¤t->mm->mmap_sem);
|
|
|
|
fput(file);
|
|
|
|
out_nattch:
|
|
down_write(&shm_ids(ns).rw_mutex);
|
|
shp = shm_lock(ns, shmid);
|
|
BUG_ON(IS_ERR(shp));
|
|
shp->shm_nattch--;
|
|
if(shp->shm_nattch == 0 &&
|
|
shp->shm_perm.mode & SHM_DEST)
|
|
shm_destroy(ns, shp);
|
|
else
|
|
shm_unlock(shp);
|
|
up_write(&shm_ids(ns).rw_mutex);
|
|
|
|
out:
|
|
return err;
|
|
|
|
out_unlock:
|
|
shm_unlock(shp);
|
|
goto out;
|
|
|
|
out_free:
|
|
kfree(sfd);
|
|
out_put_dentry:
|
|
dput(path.dentry);
|
|
goto out_nattch;
|
|
}
|
|
|
|
SYSCALL_DEFINE3(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;
|
|
}
|
|
|
|
/*
|
|
* detach and kill segment if marked destroyed.
|
|
* The work is done in shm_close.
|
|
*/
|
|
SYSCALL_DEFINE1(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 vm_area_struct *next;
|
|
#endif
|
|
|
|
if (addr & ~PAGE_MASK)
|
|
return retval;
|
|
|
|
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);
|
|
|
|
#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) {
|
|
|
|
|
|
size = vma->vm_file->f_path.dentry->d_inode->i_size;
|
|
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.
|
|
*/
|
|
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)
|
|
|
|
do_munmap(mm, vma->vm_start, vma->vm_end - vma->vm_start);
|
|
vma = next;
|
|
}
|
|
|
|
#else /* CONFIG_MMU */
|
|
/* under NOMMU conditions, the exact address to be destroyed must be
|
|
* given */
|
|
retval = -EINVAL;
|
|
if (vma->vm_start == addr && vma->vm_ops == &shm_vm_ops) {
|
|
do_munmap(mm, vma->vm_start, vma->vm_end - vma->vm_start);
|
|
retval = 0;
|
|
}
|
|
|
|
#endif
|
|
|
|
up_write(&mm->mmap_sem);
|
|
return retval;
|
|
}
|
|
|
|
#ifdef CONFIG_PROC_FS
|
|
static int sysvipc_shm_proc_show(struct seq_file *s, void *it)
|
|
{
|
|
struct shmid_kernel *shp = it;
|
|
|
|
#if BITS_PER_LONG <= 32
|
|
#define SIZE_SPEC "%10lu"
|
|
#else
|
|
#define SIZE_SPEC "%21lu"
|
|
#endif
|
|
|
|
return seq_printf(s,
|
|
"%10d %10d %4o " SIZE_SPEC " %5u %5u "
|
|
"%5lu %5u %5u %5u %5u %10lu %10lu %10lu\n",
|
|
shp->shm_perm.key,
|
|
shp->shm_perm.id,
|
|
shp->shm_perm.mode,
|
|
shp->shm_segsz,
|
|
shp->shm_cprid,
|
|
shp->shm_lprid,
|
|
shp->shm_nattch,
|
|
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);
|
|
}
|
|
#endif
|