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author | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 15:20:36 -0700 |
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committer | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 15:20:36 -0700 |
commit | 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch) | |
tree | 0bba044c4ce775e45a88a51686b5d9f90697ea9d /ipc/shm.c | |
download | kernel_samsung_smdk4412-1da177e4c3f41524e886b7f1b8a0c1fc7321cac2.tar.gz kernel_samsung_smdk4412-1da177e4c3f41524e886b7f1b8a0c1fc7321cac2.tar.bz2 kernel_samsung_smdk4412-1da177e4c3f41524e886b7f1b8a0c1fc7321cac2.zip |
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
Diffstat (limited to 'ipc/shm.c')
-rw-r--r-- | ipc/shm.c | 917 |
1 files changed, 917 insertions, 0 deletions
diff --git a/ipc/shm.c b/ipc/shm.c new file mode 100644 index 00000000000..06cd5c91056 --- /dev/null +++ b/ipc/shm.c @@ -0,0 +1,917 @@ +/* + * 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> + * + */ + +#include <linux/config.h> +#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> +#include <linux/proc_fs.h> +#include <linux/shmem_fs.h> +#include <linux/security.h> +#include <linux/syscalls.h> +#include <linux/audit.h> +#include <asm/uaccess.h> + +#include "util.h" + +#define shm_flags shm_perm.mode + +static struct file_operations shm_file_operations; +static struct vm_operations_struct shm_vm_ops; + +static struct ipc_ids shm_ids; + +#define shm_lock(id) ((struct shmid_kernel*)ipc_lock(&shm_ids,id)) +#define shm_unlock(shp) ipc_unlock(&(shp)->shm_perm) +#define shm_get(id) ((struct shmid_kernel*)ipc_get(&shm_ids,id)) +#define shm_buildid(id, seq) \ + ipc_buildid(&shm_ids, id, seq) + +static int newseg (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); +#ifdef CONFIG_PROC_FS +static int sysvipc_shm_read_proc(char *buffer, char **start, off_t offset, int length, int *eof, void *data); +#endif + +size_t shm_ctlmax = SHMMAX; +size_t shm_ctlall = SHMALL; +int shm_ctlmni = SHMMNI; + +static int shm_tot; /* total number of shared memory pages */ + +void __init shm_init (void) +{ + ipc_init_ids(&shm_ids, 1); +#ifdef CONFIG_PROC_FS + create_proc_read_entry("sysvipc/shm", 0, NULL, sysvipc_shm_read_proc, NULL); +#endif +} + +static inline int shm_checkid(struct shmid_kernel *s, int id) +{ + if (ipc_checkid(&shm_ids,&s->shm_perm,id)) + return -EIDRM; + return 0; +} + +static inline struct shmid_kernel *shm_rmid(int id) +{ + return (struct shmid_kernel *)ipc_rmid(&shm_ids,id); +} + +static inline int shm_addid(struct shmid_kernel *shp) +{ + return ipc_addid(&shm_ids, &shp->shm_perm, shm_ctlmni); +} + + + +static inline void shm_inc (int id) { + struct shmid_kernel *shp; + + if(!(shp = shm_lock(id))) + BUG(); + shp->shm_atim = get_seconds(); + shp->shm_lprid = current->tgid; + shp->shm_nattch++; + shm_unlock(shp); +} + +/* This is called by fork, once for every shm attach. */ +static void shm_open (struct vm_area_struct *shmd) +{ + shm_inc (shmd->vm_file->f_dentry->d_inode->i_ino); +} + +/* + * shm_destroy - free the struct shmid_kernel + * + * @shp: struct to free + * + * It has to be called with shp and shm_ids.sem locked, + * but returns with shp unlocked and freed. + */ +static void shm_destroy (struct shmid_kernel *shp) +{ + shm_tot -= (shp->shm_segsz + PAGE_SIZE - 1) >> PAGE_SHIFT; + shm_rmid (shp->id); + shm_unlock(shp); + if (!is_file_hugepages(shp->shm_file)) + shmem_lock(shp->shm_file, 0, shp->mlock_user); + else + user_shm_unlock(shp->shm_file->f_dentry->d_inode->i_size, + shp->mlock_user); + fput (shp->shm_file); + security_shm_free(shp); + ipc_rcu_putref(shp); +} + +/* + * remove the attach descriptor shmd. + * 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) +{ + struct file * file = shmd->vm_file; + int id = file->f_dentry->d_inode->i_ino; + struct shmid_kernel *shp; + + down (&shm_ids.sem); + /* remove from the list of attaches of the shm segment */ + if(!(shp = shm_lock(id))) + BUG(); + shp->shm_lprid = current->tgid; + shp->shm_dtim = get_seconds(); + shp->shm_nattch--; + if(shp->shm_nattch == 0 && + shp->shm_flags & SHM_DEST) + shm_destroy (shp); + else + shm_unlock(shp); + up (&shm_ids.sem); +} + +static int shm_mmap(struct file * file, struct vm_area_struct * vma) +{ + file_accessed(file); + vma->vm_ops = &shm_vm_ops; + shm_inc(file->f_dentry->d_inode->i_ino); + return 0; +} + +static struct file_operations shm_file_operations = { + .mmap = shm_mmap +}; + +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, +#ifdef CONFIG_NUMA + .set_policy = shmem_set_policy, + .get_policy = shmem_get_policy, +#endif +}; + +static int newseg (key_t key, int shmflg, size_t size) +{ + int error; + struct shmid_kernel *shp; + int numpages = (size + PAGE_SIZE -1) >> PAGE_SHIFT; + struct file * file; + char name[13]; + int id; + + if (size < SHMMIN || size > shm_ctlmax) + return -EINVAL; + + if (shm_tot + numpages >= shm_ctlall) + return -ENOSPC; + + shp = ipc_rcu_alloc(sizeof(*shp)); + if (!shp) + return -ENOMEM; + + shp->shm_perm.key = key; + shp->shm_flags = (shmflg & S_IRWXUGO); + shp->mlock_user = NULL; + + shp->shm_perm.security = NULL; + error = security_shm_alloc(shp); + if (error) { + ipc_rcu_putref(shp); + return error; + } + + if (shmflg & SHM_HUGETLB) { + /* hugetlb_zero_setup takes care of mlock user accounting */ + file = hugetlb_zero_setup(size); + shp->mlock_user = current->user; + } else { + sprintf (name, "SYSV%08x", key); + file = shmem_file_setup(name, size, VM_ACCOUNT); + } + error = PTR_ERR(file); + if (IS_ERR(file)) + goto no_file; + + error = -ENOSPC; + id = shm_addid(shp); + if(id == -1) + goto no_id; + + shp->shm_cprid = current->tgid; + shp->shm_lprid = 0; + shp->shm_atim = shp->shm_dtim = 0; + shp->shm_ctim = get_seconds(); + shp->shm_segsz = size; + shp->shm_nattch = 0; + shp->id = shm_buildid(id,shp->shm_perm.seq); + shp->shm_file = file; + file->f_dentry->d_inode->i_ino = shp->id; + if (shmflg & SHM_HUGETLB) + set_file_hugepages(file); + else + file->f_op = &shm_file_operations; + shm_tot += numpages; + shm_unlock(shp); + return shp->id; + +no_id: + fput(file); +no_file: + security_shm_free(shp); + ipc_rcu_putref(shp); + return error; +} + +asmlinkage long sys_shmget (key_t key, size_t size, int shmflg) +{ + struct shmid_kernel *shp; + int err, id = 0; + + down(&shm_ids.sem); + if (key == IPC_PRIVATE) { + err = newseg(key, shmflg, size); + } else if ((id = ipc_findkey(&shm_ids, key)) == -1) { + if (!(shmflg & IPC_CREAT)) + err = -ENOENT; + else + err = newseg(key, shmflg, size); + } else if ((shmflg & IPC_CREAT) && (shmflg & IPC_EXCL)) { + err = -EEXIST; + } else { + shp = shm_lock(id); + if(shp==NULL) + BUG(); + if (shp->shm_segsz < size) + err = -EINVAL; + else if (ipcperms(&shp->shm_perm, shmflg)) + err = -EACCES; + else { + int shmid = shm_buildid(id, shp->shm_perm.seq); + err = security_shm_associate(shp, shmflg); + if (!err) + err = shmid; + } + shm_unlock(shp); + } + up(&shm_ids.sem); + + return err; +} + +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; + } +} + +struct shm_setbuf { + uid_t uid; + gid_t gid; + mode_t mode; +}; + +static inline unsigned long copy_shmid_from_user(struct shm_setbuf *out, void __user *buf, int version) +{ + switch(version) { + case IPC_64: + { + struct shmid64_ds tbuf; + + if (copy_from_user(&tbuf, buf, sizeof(tbuf))) + return -EFAULT; + + out->uid = tbuf.shm_perm.uid; + out->gid = tbuf.shm_perm.gid; + out->mode = tbuf.shm_flags; + + return 0; + } + case IPC_OLD: + { + struct shmid_ds tbuf_old; + + if (copy_from_user(&tbuf_old, buf, sizeof(tbuf_old))) + return -EFAULT; + + out->uid = tbuf_old.shm_perm.uid; + out->gid = tbuf_old.shm_perm.gid; + out->mode = tbuf_old.shm_flags; + + 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; + } +} + +static void shm_get_stat(unsigned long *rss, unsigned long *swp) +{ + int i; + + *rss = 0; + *swp = 0; + + for (i = 0; i <= shm_ids.max_id; i++) { + struct shmid_kernel *shp; + struct inode *inode; + + shp = shm_get(i); + if(!shp) + continue; + + inode = shp->shm_file->f_dentry->d_inode; + + if (is_file_hugepages(shp->shm_file)) { + struct address_space *mapping = inode->i_mapping; + *rss += (HPAGE_SIZE/PAGE_SIZE)*mapping->nrpages; + } 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); + } + } +} + +asmlinkage long sys_shmctl (int shmid, int cmd, struct shmid_ds __user *buf) +{ + struct shm_setbuf setbuf; + struct shmid_kernel *shp; + int err, version; + + if (cmd < 0 || shmid < 0) { + err = -EINVAL; + goto out; + } + + version = ipc_parse_version(&cmd); + + 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 = shm_ctlmni; + shminfo.shmmax = shm_ctlmax; + shminfo.shmall = shm_ctlall; + + shminfo.shmmin = SHMMIN; + if(copy_shminfo_to_user (buf, &shminfo, version)) + return -EFAULT; + /* reading a integer is always atomic */ + err= shm_ids.max_id; + 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(&shm_ids.sem); + shm_info.used_ids = shm_ids.in_use; + shm_get_stat (&shm_info.shm_rss, &shm_info.shm_swp); + shm_info.shm_tot = shm_tot; + shm_info.swap_attempts = 0; + shm_info.swap_successes = 0; + err = shm_ids.max_id; + up(&shm_ids.sem); + 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; + memset(&tbuf, 0, sizeof(tbuf)); + shp = shm_lock(shmid); + if(shp==NULL) { + err = -EINVAL; + goto out; + } else if(cmd==SHM_STAT) { + err = -EINVAL; + if (shmid > shm_ids.max_id) + goto out_unlock; + result = shm_buildid(shmid, shp->shm_perm.seq); + } else { + err = shm_checkid(shp,shmid); + if(err) + goto out_unlock; + 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; + 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; + if (!is_file_hugepages(shp->shm_file)) + tbuf.shm_nattch = shp->shm_nattch; + else + tbuf.shm_nattch = file_count(shp->shm_file) - 1; + shm_unlock(shp); + if(copy_shmid_to_user (buf, &tbuf, version)) + err = -EFAULT; + else + err = result; + goto out; + } + case SHM_LOCK: + case SHM_UNLOCK: + { + shp = shm_lock(shmid); + if(shp==NULL) { + err = -EINVAL; + goto out; + } + err = shm_checkid(shp,shmid); + if(err) + goto out_unlock; + + 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); + if (!err) { + shp->shm_flags |= 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_flags &= ~SHM_LOCKED; + shp->mlock_user = NULL; + } + shm_unlock(shp); + goto out; + } + case IPC_RMID: + { + /* + * We cannot simply remove the file. The SVID states + * that the block remains until the last person + * detaches from it, then is deleted. A shmat() on + * an RMID segment is legal in older Linux and if + * we change it apps break... + * + * Instead we set a destroyed flag, and then blow + * the name away when the usage hits zero. + */ + down(&shm_ids.sem); + shp = shm_lock(shmid); + err = -EINVAL; + if (shp == NULL) + goto out_up; + err = shm_checkid(shp, shmid); + if(err) + goto out_unlock_up; + + if (current->euid != shp->shm_perm.uid && + current->euid != shp->shm_perm.cuid && + !capable(CAP_SYS_ADMIN)) { + err=-EPERM; + goto out_unlock_up; + } + + err = security_shm_shmctl(shp, cmd); + if (err) + goto out_unlock_up; + + if (shp->shm_nattch){ + shp->shm_flags |= SHM_DEST; + /* Do not find it any more */ + shp->shm_perm.key = IPC_PRIVATE; + shm_unlock(shp); + } else + shm_destroy (shp); + up(&shm_ids.sem); + goto out; + } + + case IPC_SET: + { + if (copy_shmid_from_user (&setbuf, buf, version)) { + err = -EFAULT; + goto out; + } + if ((err = audit_ipc_perms(0, setbuf.uid, setbuf.gid, setbuf.mode))) + return err; + down(&shm_ids.sem); + shp = shm_lock(shmid); + err=-EINVAL; + if(shp==NULL) + goto out_up; + err = shm_checkid(shp,shmid); + if(err) + goto out_unlock_up; + err=-EPERM; + if (current->euid != shp->shm_perm.uid && + current->euid != shp->shm_perm.cuid && + !capable(CAP_SYS_ADMIN)) { + goto out_unlock_up; + } + + err = security_shm_shmctl(shp, cmd); + if (err) + goto out_unlock_up; + + shp->shm_perm.uid = setbuf.uid; + shp->shm_perm.gid = setbuf.gid; + shp->shm_flags = (shp->shm_flags & ~S_IRWXUGO) + | (setbuf.mode & S_IRWXUGO); + shp->shm_ctim = get_seconds(); + break; + } + + default: + err = -EINVAL; + goto out; + } + + err = 0; +out_unlock_up: + shm_unlock(shp); +out_up: + up(&shm_ids.sem); + goto out; +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; + unsigned long o_flags; + int acc_mode; + void *user_addr; + + if (shmid < 0) { + err = -EINVAL; + 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 + return -EINVAL; + } + flags = MAP_SHARED | MAP_FIXED; + } else { + if ((shmflg & SHM_REMAP)) + return -EINVAL; + + flags = MAP_SHARED; + } + + if (shmflg & SHM_RDONLY) { + prot = PROT_READ; + o_flags = O_RDONLY; + acc_mode = S_IRUGO; + } else { + prot = PROT_READ | PROT_WRITE; + o_flags = O_RDWR; + acc_mode = S_IRUGO | S_IWUGO; + } + 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... + */ + shp = shm_lock(shmid); + if(shp == NULL) { + err = -EINVAL; + goto out; + } + err = shm_checkid(shp,shmid); + if (err) { + shm_unlock(shp); + goto out; + } + if (ipcperms(&shp->shm_perm, acc_mode)) { + shm_unlock(shp); + err = -EACCES; + goto out; + } + + err = security_shm_shmat(shp, shmaddr, shmflg); + if (err) { + shm_unlock(shp); + return err; + } + + file = shp->shm_file; + size = i_size_read(file->f_dentry->d_inode); + shp->shm_nattch++; + shm_unlock(shp); + + down_write(¤t->mm->mmap_sem); + if (addr && !(shmflg & SHM_REMAP)) { + user_addr = ERR_PTR(-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 = (void*) do_mmap (file, addr, size, prot, flags, 0); + +invalid: + up_write(¤t->mm->mmap_sem); + + down (&shm_ids.sem); + if(!(shp = shm_lock(shmid))) + BUG(); + shp->shm_nattch--; + if(shp->shm_nattch == 0 && + shp->shm_flags & SHM_DEST) + shm_destroy (shp); + else + shm_unlock(shp); + up (&shm_ids.sem); + + *raddr = (unsigned long) user_addr; + err = 0; + if (IS_ERR(user_addr)) + err = PTR_ERR(user_addr); +out: + return err; +} + +/* + * 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; + + 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. + */ + if ((vma->vm_ops == &shm_vm_ops || is_vm_hugetlb_page(vma)) && + (vma->vm_start - addr)/PAGE_SIZE == vma->vm_pgoff) { + + + size = vma->vm_file->f_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. + */ + 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 || is_vm_hugetlb_page(vma)) && + (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 +static int sysvipc_shm_read_proc(char *buffer, char **start, off_t offset, int length, int *eof, void *data) +{ + off_t pos = 0; + off_t begin = 0; + int i, len = 0; + + down(&shm_ids.sem); + len += sprintf(buffer, " key shmid perms size cpid lpid nattch uid gid cuid cgid atime dtime ctime\n"); + + for(i = 0; i <= shm_ids.max_id; i++) { + struct shmid_kernel* shp; + + shp = shm_lock(i); + if(shp!=NULL) { +#define SMALL_STRING "%10d %10d %4o %10u %5u %5u %5d %5u %5u %5u %5u %10lu %10lu %10lu\n" +#define BIG_STRING "%10d %10d %4o %21u %5u %5u %5d %5u %5u %5u %5u %10lu %10lu %10lu\n" + char *format; + + if (sizeof(size_t) <= sizeof(int)) + format = SMALL_STRING; + else + format = BIG_STRING; + len += sprintf(buffer + len, format, + shp->shm_perm.key, + shm_buildid(i, shp->shm_perm.seq), + shp->shm_flags, + 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_perm.uid, + shp->shm_perm.gid, + shp->shm_perm.cuid, + shp->shm_perm.cgid, + shp->shm_atim, + shp->shm_dtim, + shp->shm_ctim); + shm_unlock(shp); + + pos += len; + if(pos < offset) { + len = 0; + begin = pos; + } + if(pos > offset + length) + goto done; + } + } + *eof = 1; +done: + up(&shm_ids.sem); + *start = buffer + (offset - begin); + len -= (offset - begin); + if(len > length) + len = length; + if(len < 0) + len = 0; + return len; +} +#endif |