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Diffstat (limited to 'ipc/shm.c')
-rw-r--r--ipc/shm.c316
1 files changed, 192 insertions, 124 deletions
diff --git a/ipc/shm.c b/ipc/shm.c
index 5fc5cf50cf1..3818fae625c 100644
--- a/ipc/shm.c
+++ b/ipc/shm.c
@@ -35,7 +35,7 @@
#include <linux/capability.h>
#include <linux/ptrace.h>
#include <linux/seq_file.h>
-#include <linux/mutex.h>
+#include <linux/rwsem.h>
#include <linux/nsproxy.h>
#include <linux/mount.h>
@@ -59,17 +59,11 @@ static struct ipc_ids init_shm_ids;
#define shm_ids(ns) (*((ns)->ids[IPC_SHM_IDS]))
-#define shm_lock(ns, id) \
- ((struct shmid_kernel*)ipc_lock(&shm_ids(ns),id))
#define shm_unlock(shp) \
ipc_unlock(&(shp)->shm_perm)
-#define shm_get(ns, id) \
- ((struct shmid_kernel*)ipc_get(&shm_ids(ns),id))
-#define shm_buildid(ns, id, seq) \
- ipc_buildid(&shm_ids(ns), id, seq)
+#define shm_buildid(id, seq) ipc_buildid(id, seq)
-static int newseg (struct ipc_namespace *ns, key_t key,
- int shmflg, size_t size);
+static int newseg(struct ipc_namespace *, struct ipc_params *);
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);
@@ -84,9 +78,13 @@ static void __shm_init_ns(struct ipc_namespace *ns, struct ipc_ids *ids)
ns->shm_ctlall = SHMALL;
ns->shm_ctlmni = SHMMNI;
ns->shm_tot = 0;
- ipc_init_ids(ids, 1);
+ ipc_init_ids(ids);
}
+/*
+ * Called with shm_ids.rw_mutex (writer) and the shp structure locked.
+ * Only shm_ids.rw_mutex remains locked on exit.
+ */
static void do_shm_rmid(struct ipc_namespace *ns, struct shmid_kernel *shp)
{
if (shp->shm_nattch){
@@ -112,20 +110,24 @@ int shm_init_ns(struct ipc_namespace *ns)
void shm_exit_ns(struct ipc_namespace *ns)
{
- int i;
struct shmid_kernel *shp;
+ int next_id;
+ int total, in_use;
+
+ down_write(&shm_ids(ns).rw_mutex);
- mutex_lock(&shm_ids(ns).mutex);
- for (i = 0; i <= shm_ids(ns).max_id; i++) {
- shp = shm_lock(ns, i);
+ in_use = shm_ids(ns).in_use;
+
+ for (total = 0, next_id = 0; total < in_use; next_id++) {
+ shp = idr_find(&shm_ids(ns).ipcs_idr, next_id);
if (shp == NULL)
continue;
-
+ ipc_lock_by_ptr(&shp->shm_perm);
do_shm_rmid(ns, shp);
+ total++;
}
- mutex_unlock(&shm_ids(ns).mutex);
+ up_write(&shm_ids(ns).rw_mutex);
- ipc_fini_ids(ns->ids[IPC_SHM_IDS]);
kfree(ns->ids[IPC_SHM_IDS]);
ns->ids[IPC_SHM_IDS] = NULL;
}
@@ -138,17 +140,49 @@ void __init shm_init (void)
IPC_SHM_IDS, sysvipc_shm_proc_show);
}
-static inline int shm_checkid(struct ipc_namespace *ns,
- struct shmid_kernel *s, int id)
+/*
+ * shm_lock_(check_)down routines are called in the paths where the rw_mutex
+ * is held to protect access to the idr tree.
+ */
+static inline struct shmid_kernel *shm_lock_down(struct ipc_namespace *ns,
+ int id)
{
- if (ipc_checkid(&shm_ids(ns), &s->shm_perm, id))
- return -EIDRM;
- return 0;
+ struct kern_ipc_perm *ipcp = ipc_lock_down(&shm_ids(ns), id);
+
+ return container_of(ipcp, struct shmid_kernel, shm_perm);
+}
+
+static inline struct shmid_kernel *shm_lock_check_down(
+ struct ipc_namespace *ns,
+ int id)
+{
+ struct kern_ipc_perm *ipcp = ipc_lock_check_down(&shm_ids(ns), id);
+
+ return container_of(ipcp, struct shmid_kernel, shm_perm);
+}
+
+/*
+ * shm_lock_(check_) routines are called in the paths where the rw_mutex
+ * is not held.
+ */
+static inline struct shmid_kernel *shm_lock(struct ipc_namespace *ns, int id)
+{
+ struct kern_ipc_perm *ipcp = ipc_lock(&shm_ids(ns), id);
+
+ return container_of(ipcp, struct shmid_kernel, shm_perm);
+}
+
+static inline struct shmid_kernel *shm_lock_check(struct ipc_namespace *ns,
+ int id)
+{
+ struct kern_ipc_perm *ipcp = ipc_lock_check(&shm_ids(ns), id);
+
+ return container_of(ipcp, struct shmid_kernel, shm_perm);
}
-static inline struct shmid_kernel *shm_rmid(struct ipc_namespace *ns, int id)
+static inline void shm_rmid(struct ipc_namespace *ns, struct shmid_kernel *s)
{
- return (struct shmid_kernel *)ipc_rmid(&shm_ids(ns), id);
+ ipc_rmid(&shm_ids(ns), &s->shm_perm);
}
static inline int shm_addid(struct ipc_namespace *ns, struct shmid_kernel *shp)
@@ -166,9 +200,9 @@ static void shm_open(struct vm_area_struct *vma)
struct shmid_kernel *shp;
shp = shm_lock(sfd->ns, sfd->id);
- BUG_ON(!shp);
+ BUG_ON(IS_ERR(shp));
shp->shm_atim = get_seconds();
- shp->shm_lprid = current->tgid;
+ shp->shm_lprid = task_tgid_vnr(current);
shp->shm_nattch++;
shm_unlock(shp);
}
@@ -176,15 +210,16 @@ static void shm_open(struct vm_area_struct *vma)
/*
* shm_destroy - free the struct shmid_kernel
*
+ * @ns: namespace
* @shp: struct to free
*
- * It has to be called with shp and shm_ids.mutex locked,
+ * It has to be called with shp and shm_ids.rw_mutex (writer) locked,
* but returns with shp unlocked and freed.
*/
static void shm_destroy(struct ipc_namespace *ns, struct shmid_kernel *shp)
{
ns->shm_tot -= (shp->shm_segsz + PAGE_SIZE - 1) >> PAGE_SHIFT;
- shm_rmid(ns, shp->id);
+ shm_rmid(ns, shp);
shm_unlock(shp);
if (!is_file_hugepages(shp->shm_file))
shmem_lock(shp->shm_file, 0, shp->mlock_user);
@@ -209,11 +244,11 @@ static void shm_close(struct vm_area_struct *vma)
struct shmid_kernel *shp;
struct ipc_namespace *ns = sfd->ns;
- mutex_lock(&shm_ids(ns).mutex);
+ down_write(&shm_ids(ns).rw_mutex);
/* remove from the list of attaches of the shm segment */
- shp = shm_lock(ns, sfd->id);
- BUG_ON(!shp);
- shp->shm_lprid = current->tgid;
+ shp = shm_lock_down(ns, sfd->id);
+ BUG_ON(IS_ERR(shp));
+ shp->shm_lprid = task_tgid_vnr(current);
shp->shm_dtim = get_seconds();
shp->shm_nattch--;
if(shp->shm_nattch == 0 &&
@@ -221,7 +256,7 @@ static void shm_close(struct vm_area_struct *vma)
shm_destroy(ns, shp);
else
shm_unlock(shp);
- mutex_unlock(&shm_ids(ns).mutex);
+ up_write(&shm_ids(ns).rw_mutex);
}
static int shm_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
@@ -337,8 +372,19 @@ static struct vm_operations_struct shm_vm_ops = {
#endif
};
-static int newseg (struct ipc_namespace *ns, key_t key, int shmflg, size_t size)
+/**
+ * newseg - Create a new shared memory segment
+ * @ns: namespace
+ * @params: ptr to the structure that contains key, size and shmflg
+ *
+ * Called with shm_ids.rw_mutex held as a writer.
+ */
+
+static int newseg(struct ipc_namespace *ns, struct ipc_params *params)
{
+ key_t key = params->key;
+ int shmflg = params->flg;
+ size_t size = params->u.size;
int error;
struct shmid_kernel *shp;
int numpages = (size + PAGE_SIZE -1) >> PAGE_SHIFT;
@@ -387,28 +433,30 @@ static int newseg (struct ipc_namespace *ns, key_t key, int shmflg, size_t size)
if (IS_ERR(file))
goto no_file;
- error = -ENOSPC;
id = shm_addid(ns, shp);
- if(id == -1)
+ if (id < 0) {
+ error = id;
goto no_id;
+ }
- shp->shm_cprid = current->tgid;
+ shp->shm_cprid = task_tgid_vnr(current);
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(ns, id, shp->shm_perm.seq);
+ shp->shm_perm.id = shm_buildid(id, shp->shm_perm.seq);
shp->shm_file = file;
/*
* shmid gets reported as "inode#" in /proc/pid/maps.
* proc-ps tools use this. Changing this will break them.
*/
- file->f_dentry->d_inode->i_ino = shp->id;
+ file->f_dentry->d_inode->i_ino = shp->shm_perm.id;
ns->shm_tot += numpages;
+ error = shp->shm_perm.id;
shm_unlock(shp);
- return shp->id;
+ return error;
no_id:
fput(file);
@@ -418,42 +466,49 @@ no_file:
return error;
}
-asmlinkage long sys_shmget (key_t key, size_t size, int shmflg)
+/*
+ * Called with shm_ids.rw_mutex and ipcp locked.
+ */
+static inline int shm_security(struct kern_ipc_perm *ipcp, int shmflg)
{
struct shmid_kernel *shp;
- int err, id = 0;
+
+ shp = container_of(ipcp, struct shmid_kernel, shm_perm);
+ return security_shm_associate(shp, shmflg);
+}
+
+/*
+ * Called with shm_ids.rw_mutex and ipcp locked.
+ */
+static inline int shm_more_checks(struct kern_ipc_perm *ipcp,
+ struct ipc_params *params)
+{
+ struct shmid_kernel *shp;
+
+ shp = container_of(ipcp, struct shmid_kernel, shm_perm);
+ if (shp->shm_segsz < params->u.size)
+ return -EINVAL;
+
+ return 0;
+}
+
+asmlinkage long sys_shmget (key_t key, size_t size, int shmflg)
+{
struct ipc_namespace *ns;
+ struct ipc_ops shm_ops;
+ struct ipc_params shm_params;
ns = current->nsproxy->ipc_ns;
- mutex_lock(&shm_ids(ns).mutex);
- if (key == IPC_PRIVATE) {
- err = newseg(ns, key, shmflg, size);
- } else if ((id = ipc_findkey(&shm_ids(ns), key)) == -1) {
- if (!(shmflg & IPC_CREAT))
- err = -ENOENT;
- else
- err = newseg(ns, key, shmflg, size);
- } else if ((shmflg & IPC_CREAT) && (shmflg & IPC_EXCL)) {
- err = -EEXIST;
- } else {
- shp = shm_lock(ns, id);
- BUG_ON(shp==NULL);
- if (shp->shm_segsz < size)
- err = -EINVAL;
- else if (ipcperms(&shp->shm_perm, shmflg))
- err = -EACCES;
- else {
- int shmid = shm_buildid(ns, id, shp->shm_perm.seq);
- err = security_shm_associate(shp, shmflg);
- if (!err)
- err = shmid;
- }
- shm_unlock(shp);
- }
- mutex_unlock(&shm_ids(ns).mutex);
+ shm_ops.getnew = newseg;
+ shm_ops.associate = shm_security;
+ shm_ops.more_checks = shm_more_checks;
- return err;
+ shm_params.key = key;
+ shm_params.flg = shmflg;
+ shm_params.u.size = size;
+
+ return ipcget(ns, &shm_ids(ns), &shm_ops, &shm_params);
}
static inline unsigned long copy_shmid_to_user(void __user *buf, struct shmid64_ds *in, int version)
@@ -547,20 +602,26 @@ static inline unsigned long copy_shminfo_to_user(void __user *buf, struct shminf
}
}
+/*
+ * 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 i;
+ int next_id;
+ int total, in_use;
*rss = 0;
*swp = 0;
- for (i = 0; i <= shm_ids(ns).max_id; i++) {
+ in_use = shm_ids(ns).in_use;
+
+ for (total = 0, next_id = 0; total < in_use; next_id++) {
struct shmid_kernel *shp;
struct inode *inode;
- shp = shm_get(ns, i);
- if(!shp)
+ shp = idr_find(&shm_ids(ns).ipcs_idr, next_id);
+ if (shp == NULL)
continue;
inode = shp->shm_file->f_path.dentry->d_inode;
@@ -575,6 +636,8 @@ static void shm_get_stat(struct ipc_namespace *ns, unsigned long *rss,
*swp += info->swapped;
spin_unlock(&info->lock);
}
+
+ total++;
}
}
@@ -610,8 +673,11 @@ asmlinkage long sys_shmctl (int shmid, int cmd, struct shmid_ds __user *buf)
shminfo.shmmin = SHMMIN;
if(copy_shminfo_to_user (buf, &shminfo, version))
return -EFAULT;
- /* reading a integer is always atomic */
- err= shm_ids(ns).max_id;
+
+ 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;
@@ -625,14 +691,14 @@ asmlinkage long sys_shmctl (int shmid, int cmd, struct shmid_ds __user *buf)
return err;
memset(&shm_info,0,sizeof(shm_info));
- mutex_lock(&shm_ids(ns).mutex);
+ 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 = shm_ids(ns).max_id;
- mutex_unlock(&shm_ids(ns).mutex);
+ 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;
@@ -646,20 +712,25 @@ asmlinkage long sys_shmctl (int shmid, int cmd, struct shmid_ds __user *buf)
{
struct shmid64_ds tbuf;
int result;
- memset(&tbuf, 0, sizeof(tbuf));
- shp = shm_lock(ns, shmid);
- if(shp==NULL) {
- err = -EINVAL;
+
+ if (!buf) {
+ err = -EFAULT;
goto out;
- } else if(cmd==SHM_STAT) {
- err = -EINVAL;
- if (shmid > shm_ids(ns).max_id)
- goto out_unlock;
- result = shm_buildid(ns, shmid, shp->shm_perm.seq);
+ }
+
+ 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 {
- err = shm_checkid(ns, shp,shmid);
- if(err)
- goto out_unlock;
+ shp = shm_lock_check(ns, shmid);
+ if (IS_ERR(shp)) {
+ err = PTR_ERR(shp);
+ goto out;
+ }
result = 0;
}
err=-EACCES;
@@ -668,6 +739,7 @@ asmlinkage long sys_shmctl (int shmid, int cmd, struct shmid_ds __user *buf)
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;
@@ -686,14 +758,11 @@ asmlinkage long sys_shmctl (int shmid, int cmd, struct shmid_ds __user *buf)
case SHM_LOCK:
case SHM_UNLOCK:
{
- shp = shm_lock(ns, shmid);
- if(shp==NULL) {
- err = -EINVAL;
+ shp = shm_lock_check(ns, shmid);
+ if (IS_ERR(shp)) {
+ err = PTR_ERR(shp);
goto out;
}
- err = shm_checkid(ns, shp,shmid);
- if(err)
- goto out_unlock;
err = audit_ipc_obj(&(shp->shm_perm));
if (err)
@@ -742,14 +811,12 @@ asmlinkage long sys_shmctl (int shmid, int cmd, struct shmid_ds __user *buf)
* Instead we set a destroyed flag, and then blow
* the name away when the usage hits zero.
*/
- mutex_lock(&shm_ids(ns).mutex);
- shp = shm_lock(ns, shmid);
- err = -EINVAL;
- if (shp == NULL)
+ down_write(&shm_ids(ns).rw_mutex);
+ shp = shm_lock_check_down(ns, shmid);
+ if (IS_ERR(shp)) {
+ err = PTR_ERR(shp);
goto out_up;
- err = shm_checkid(ns, shp, shmid);
- if(err)
- goto out_unlock_up;
+ }
err = audit_ipc_obj(&(shp->shm_perm));
if (err)
@@ -767,24 +834,27 @@ asmlinkage long sys_shmctl (int shmid, int cmd, struct shmid_ds __user *buf)
goto out_unlock_up;
do_shm_rmid(ns, shp);
- mutex_unlock(&shm_ids(ns).mutex);
+ up_write(&shm_ids(ns).rw_mutex);
goto out;
}
case IPC_SET:
{
+ if (!buf) {
+ err = -EFAULT;
+ goto out;
+ }
+
if (copy_shmid_from_user (&setbuf, buf, version)) {
err = -EFAULT;
goto out;
}
- mutex_lock(&shm_ids(ns).mutex);
- shp = shm_lock(ns, shmid);
- err=-EINVAL;
- if(shp==NULL)
+ down_write(&shm_ids(ns).rw_mutex);
+ shp = shm_lock_check_down(ns, shmid);
+ if (IS_ERR(shp)) {
+ err = PTR_ERR(shp);
goto out_up;
- err = shm_checkid(ns, shp,shmid);
- if(err)
- goto out_unlock_up;
+ }
err = audit_ipc_obj(&(shp->shm_perm));
if (err)
goto out_unlock_up;
@@ -819,7 +889,7 @@ asmlinkage long sys_shmctl (int shmid, int cmd, struct shmid_ds __user *buf)
out_unlock_up:
shm_unlock(shp);
out_up:
- mutex_unlock(&shm_ids(ns).mutex);
+ up_write(&shm_ids(ns).rw_mutex);
goto out;
out_unlock:
shm_unlock(shp);
@@ -890,13 +960,11 @@ long do_shmat(int shmid, char __user *shmaddr, int shmflg, ulong *raddr)
* additional creator id...
*/
ns = current->nsproxy->ipc_ns;
- shp = shm_lock(ns, shmid);
- if(shp == NULL)
+ shp = shm_lock_check(ns, shmid);
+ if (IS_ERR(shp)) {
+ err = PTR_ERR(shp);
goto out;
-
- err = shm_checkid(ns, shp,shmid);
- if (err)
- goto out_unlock;
+ }
err = -EACCES;
if (ipcperms(&shp->shm_perm, acc_mode))
@@ -925,7 +993,7 @@ long do_shmat(int shmid, char __user *shmaddr, int shmflg, ulong *raddr)
file->private_data = sfd;
file->f_mapping = shp->shm_file->f_mapping;
- sfd->id = shp->id;
+ sfd->id = shp->shm_perm.id;
sfd->ns = get_ipc_ns(ns);
sfd->file = shp->shm_file;
sfd->vm_ops = NULL;
@@ -955,16 +1023,16 @@ invalid:
fput(file);
out_nattch:
- mutex_lock(&shm_ids(ns).mutex);
- shp = shm_lock(ns, shmid);
- BUG_ON(!shp);
+ down_write(&shm_ids(ns).rw_mutex);
+ shp = shm_lock_down(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);
- mutex_unlock(&shm_ids(ns).mutex);
+ up_write(&shm_ids(ns).rw_mutex);
out:
return err;
@@ -1094,7 +1162,7 @@ static int sysvipc_shm_proc_show(struct seq_file *s, void *it)
format = BIG_STRING;
return seq_printf(s, format,
shp->shm_perm.key,
- shp->id,
+ shp->shm_perm.id,
shp->shm_perm.mode,
shp->shm_segsz,
shp->shm_cprid,