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-rw-r--r--ipc/shm.c240
1 files changed, 155 insertions, 85 deletions
diff --git a/ipc/shm.c b/ipc/shm.c
index 5bb617f6306e..eb57e2254304 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(&current->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(&current->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,