diff options
Diffstat (limited to 'ipc')
-rw-r--r-- | ipc/shm.c | 240 |
1 files changed, 155 insertions, 85 deletions
diff --git a/ipc/shm.c b/ipc/shm.c index 5bb617f6306..eb57e225430 100644 --- a/ipc/shm.c +++ b/ipc/shm.c @@ -37,11 +37,21 @@ #include <linux/seq_file.h> #include <linux/mutex.h> #include <linux/nsproxy.h> +#include <linux/mount.h> #include <asm/uaccess.h> #include "util.h" +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)) + static const struct file_operations shm_file_operations; static struct vm_operations_struct shm_vm_ops; @@ -60,8 +70,8 @@ static struct ipc_ids init_shm_ids; static int newseg (struct ipc_namespace *ns, key_t key, int shmflg, size_t size); -static void shm_open (struct vm_area_struct *shmd); -static void shm_close (struct vm_area_struct *shmd); +static void shm_open(struct vm_area_struct *vma); +static void shm_close(struct vm_area_struct *vma); static void shm_destroy (struct ipc_namespace *ns, struct shmid_kernel *shp); #ifdef CONFIG_PROC_FS static int sysvipc_shm_proc_show(struct seq_file *s, void *it); @@ -150,11 +160,14 @@ static inline int shm_addid(struct ipc_namespace *ns, struct shmid_kernel *shp) -static inline void shm_inc(struct ipc_namespace *ns, int id) +/* This is called by fork, once for every shm attach. */ +static void shm_open(struct vm_area_struct *vma) { + struct file *file = vma->vm_file; + struct shm_file_data *sfd = shm_file_data(file); struct shmid_kernel *shp; - shp = shm_lock(ns, id); + shp = shm_lock(sfd->ns, sfd->id); BUG_ON(!shp); shp->shm_atim = get_seconds(); shp->shm_lprid = current->tgid; @@ -162,15 +175,6 @@ static inline void shm_inc(struct ipc_namespace *ns, int id) shm_unlock(shp); } -#define shm_file_ns(file) (*((struct ipc_namespace **)&(file)->private_data)) - -/* This is called by fork, once for every shm attach. */ -static void shm_open(struct vm_area_struct *shmd) -{ - shm_inc(shm_file_ns(shmd->vm_file), - shmd->vm_file->f_path.dentry->d_inode->i_ino); -} - /* * shm_destroy - free the struct shmid_kernel * @@ -195,23 +199,21 @@ static void shm_destroy(struct ipc_namespace *ns, struct shmid_kernel *shp) } /* - * remove the attach descriptor shmd. + * remove the attach descriptor vma. * 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. */ -static void shm_close (struct vm_area_struct *shmd) +static void shm_close(struct vm_area_struct *vma) { - struct file * file = shmd->vm_file; - int id = file->f_path.dentry->d_inode->i_ino; + struct file * file = vma->vm_file; + struct shm_file_data *sfd = shm_file_data(file); struct shmid_kernel *shp; - struct ipc_namespace *ns; - - ns = shm_file_ns(file); + struct ipc_namespace *ns = sfd->ns; mutex_lock(&shm_ids(ns).mutex); /* remove from the list of attaches of the shm segment */ - shp = shm_lock(ns, id); + shp = shm_lock(ns, sfd->id); BUG_ON(!shp); shp->shm_lprid = current->tgid; shp->shm_dtim = get_seconds(); @@ -224,46 +226,91 @@ static void shm_close (struct vm_area_struct *shmd) mutex_unlock(&shm_ids(ns).mutex); } +struct page *shm_nopage(struct vm_area_struct *vma, unsigned long address, + int *type) +{ + struct file *file = vma->vm_file; + struct shm_file_data *sfd = shm_file_data(file); + + return sfd->vm_ops->nopage(vma, address, type); +} + +#ifdef CONFIG_NUMA +int shm_set_policy(struct vm_area_struct *vma, struct mempolicy *new) +{ + 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; +} + +struct mempolicy *shm_get_policy(struct vm_area_struct *vma, unsigned long addr) +{ + 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); + else + pol = vma->vm_policy; + return pol; +} +#endif + static int shm_mmap(struct file * file, struct vm_area_struct * vma) { + struct shm_file_data *sfd = shm_file_data(file); int ret; - ret = shmem_mmap(file, vma); - if (ret == 0) { - vma->vm_ops = &shm_vm_ops; - if (!(vma->vm_flags & VM_WRITE)) - vma->vm_flags &= ~VM_MAYWRITE; - shm_inc(shm_file_ns(file), file->f_path.dentry->d_inode->i_ino); - } + ret = sfd->file->f_op->mmap(sfd->file, vma); + if (ret != 0) + return ret; + sfd->vm_ops = vma->vm_ops; + vma->vm_ops = &shm_vm_ops; + shm_open(vma); return ret; } static int shm_release(struct inode *ino, struct file *file) { - struct ipc_namespace *ns; + struct shm_file_data *sfd = shm_file_data(file); - ns = shm_file_ns(file); - put_ipc_ns(ns); - shm_file_ns(file) = NULL; + put_ipc_ns(sfd->ns); + shm_file_data(file) = NULL; + kfree(sfd); return 0; } +#ifndef CONFIG_MMU +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); +} +#else +#define shm_get_unmapped_area NULL +#endif + static const struct file_operations shm_file_operations = { .mmap = shm_mmap, .release = shm_release, -#ifndef CONFIG_MMU - .get_unmapped_area = shmem_get_unmapped_area, -#endif + .get_unmapped_area = shm_get_unmapped_area, }; 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 */ - .nopage = shmem_nopage, -#if defined(CONFIG_NUMA) && defined(CONFIG_SHMEM) - .set_policy = shmem_set_policy, - .get_policy = shmem_get_policy, + .nopage = shm_nopage, +#if defined(CONFIG_NUMA) + .set_policy = shm_set_policy, + .get_policy = shm_get_policy, #endif }; @@ -330,13 +377,6 @@ static int newseg (struct ipc_namespace *ns, key_t key, int shmflg, size_t size) shp->shm_nattch = 0; shp->id = shm_buildid(ns, id, shp->shm_perm.seq); shp->shm_file = file; - file->f_path.dentry->d_inode->i_ino = shp->id; - - shm_file_ns(file) = get_ipc_ns(ns); - - /* Hugetlb ops would have already been assigned. */ - if (!(shmflg & SHM_HUGETLB)) - file->f_op = &shm_file_operations; ns->shm_tot += numpages; shm_unlock(shp); @@ -607,10 +647,7 @@ asmlinkage long sys_shmctl (int shmid, int cmd, struct shmid_ds __user *buf) tbuf.shm_ctime = shp->shm_ctim; tbuf.shm_cpid = shp->shm_cprid; tbuf.shm_lpid = shp->shm_lprid; - if (!is_file_hugepages(shp->shm_file)) - tbuf.shm_nattch = shp->shm_nattch; - else - tbuf.shm_nattch = file_count(shp->shm_file) - 1; + tbuf.shm_nattch = shp->shm_nattch; shm_unlock(shp); if(copy_shmid_to_user (buf, &tbuf, version)) err = -EFAULT; @@ -779,13 +816,16 @@ long do_shmat(int shmid, char __user *shmaddr, int shmflg, ulong *raddr) unsigned long flags; unsigned long prot; int acc_mode; - void *user_addr; + unsigned long user_addr; struct ipc_namespace *ns; + struct shm_file_data *sfd; + struct path path; + mode_t f_mode; - if (shmid < 0) { - err = -EINVAL; + err = -EINVAL; + if (shmid < 0) goto out; - } else if ((addr = (ulong)shmaddr)) { + else if ((addr = (ulong)shmaddr)) { if (addr & (SHMLBA-1)) { if (shmflg & SHM_RND) addr &= ~(SHMLBA-1); /* round down */ @@ -793,12 +833,12 @@ long do_shmat(int shmid, char __user *shmaddr, int shmflg, ulong *raddr) #ifndef __ARCH_FORCE_SHMLBA if (addr & ~PAGE_MASK) #endif - return -EINVAL; + goto out; } flags = MAP_SHARED | MAP_FIXED; } else { if ((shmflg & SHM_REMAP)) - return -EINVAL; + goto out; flags = MAP_SHARED; } @@ -806,9 +846,11 @@ long do_shmat(int shmid, char __user *shmaddr, int shmflg, ulong *raddr) 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; @@ -821,35 +863,50 @@ long do_shmat(int shmid, char __user *shmaddr, int shmflg, ulong *raddr) */ ns = current->nsproxy->ipc_ns; shp = shm_lock(ns, shmid); - if(shp == NULL) { - err = -EINVAL; + if(shp == NULL) goto out; - } + err = shm_checkid(ns, shp,shmid); - if (err) { - shm_unlock(shp); - goto out; - } - if (ipcperms(&shp->shm_perm, acc_mode)) { - shm_unlock(shp); - err = -EACCES; - goto out; - } + if (err) + goto out_unlock; + + err = -EACCES; + if (ipcperms(&shp->shm_perm, acc_mode)) + goto out_unlock; err = security_shm_shmat(shp, shmaddr, shmflg); - if (err) { - shm_unlock(shp); - return err; - } - - file = shp->shm_file; - size = i_size_read(file->f_path.dentry->d_inode); + if (err) + goto out_unlock; + + path.dentry = dget(shp->shm_file->f_path.dentry); + path.mnt = mntget(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_path; + + err = -ENOMEM; + file = get_empty_filp(); + if (!file) + goto out_free; + + file->f_op = &shm_file_operations; + file->private_data = sfd; + file->f_path = path; + file->f_mapping = shp->shm_file->f_mapping; + file->f_mode = f_mode; + sfd->id = shp->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)) { - user_addr = ERR_PTR(-EINVAL); + err = -EINVAL; if (find_vma_intersection(current->mm, addr, addr + size)) goto invalid; /* @@ -861,11 +918,17 @@ long do_shmat(int shmid, char __user *shmaddr, int shmflg, ulong *raddr) goto invalid; } - user_addr = (void*) do_mmap (file, addr, size, prot, flags, 0); - + 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: mutex_lock(&shm_ids(ns).mutex); shp = shm_lock(ns, shmid); BUG_ON(!shp); @@ -877,12 +940,19 @@ invalid: shm_unlock(shp); mutex_unlock(&shm_ids(ns).mutex); - *raddr = (unsigned long) user_addr; - err = 0; - if (IS_ERR(user_addr)) - err = PTR_ERR(user_addr); out: return err; + +out_unlock: + shm_unlock(shp); + goto out; + +out_free: + kfree(sfd); +out_put_path: + dput(path.dentry); + mntput(path.mnt); + goto out_nattch; } asmlinkage long sys_shmat(int shmid, char __user *shmaddr, int shmflg) @@ -944,7 +1014,7 @@ asmlinkage long sys_shmdt(char __user *shmaddr) * 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 || is_vm_hugetlb_page(vma)) && + if ((vma->vm_ops == &shm_vm_ops) && (vma->vm_start - addr)/PAGE_SIZE == vma->vm_pgoff) { @@ -973,7 +1043,7 @@ asmlinkage long sys_shmdt(char __user *shmaddr) next = vma->vm_next; /* finding a matching vma now does not alter retval */ - if ((vma->vm_ops == &shm_vm_ops || is_vm_hugetlb_page(vma)) && + 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); @@ -1004,7 +1074,7 @@ static int sysvipc_shm_proc_show(struct seq_file *s, void *it) shp->shm_segsz, shp->shm_cprid, shp->shm_lprid, - is_file_hugepages(shp->shm_file) ? (file_count(shp->shm_file) - 1) : shp->shm_nattch, + shp->shm_nattch, shp->shm_perm.uid, shp->shm_perm.gid, shp->shm_perm.cuid, |