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Commit 9ba720c1 authored by Al Viro's avatar Al Viro
Browse files

shmctl: split the work from copyin/copyout 



Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
parent 5771a8c0

ipc/shm.c

+172 −175
Original line number Diff line number Diff line
@@ -813,23 +813,17 @@ static void shm_get_stat(struct ipc_namespace *ns, unsigned long *rss, 
 * NOTE: no locks must be held, the rwsem 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 shmid64_ds *shmid64)

{

	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;

	}



	down_write(&shm_ids(ns).rwsem);

	rcu_read_lock();



	ipcp = ipcctl_pre_down_nolock(ns, &shm_ids(ns), shmid, cmd,

				      &shmid64.shm_perm, 0);

				      &shmid64->shm_perm, 0);

	if (IS_ERR(ipcp)) {

		err = PTR_ERR(ipcp);

		goto out_unlock1;
@@ -849,7 +843,7 @@ static int shmctl_down(struct ipc_namespace *ns, int shmid, int cmd, 
		goto out_up;

	case IPC_SET:

		ipc_lock_object(&shp->shm_perm);

		err = ipc_update_perm(&shmid64.shm_perm, ipcp);

		err = ipc_update_perm(&shmid64->shm_perm, ipcp);

		if (err)

			goto out_unlock0;

		shp->shm_ctim = get_seconds();
@@ -868,67 +862,51 @@ static int shmctl_down(struct ipc_namespace *ns, int shmid, int cmd, 
	return err;

}



static int shmctl_nolock(struct ipc_namespace *ns, int shmid,

			 int cmd, int version, void __user *buf)

{

	int err;

	struct shmid_kernel *shp;



	/* preliminary security checks for *_INFO */

	if (cmd == IPC_INFO || cmd == SHM_INFO) {

		err = security_shm_shmctl(NULL, cmd);

		if (err)

			return err;

	}



	switch (cmd) {

	case IPC_INFO:

static int shmctl_ipc_info(struct ipc_namespace *ns,

			   struct shminfo64 *shminfo)

{

		struct shminfo64 shminfo;



		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;



	int err = security_shm_shmctl(NULL, IPC_INFO);

	if (!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;

		down_read(&shm_ids(ns).rwsem);

		err = ipc_get_maxid(&shm_ids(ns));

		up_read(&shm_ids(ns).rwsem);



		if (err < 0)

			err = 0;

		goto out;

	}

	case SHM_INFO:

	{

		struct shm_info shm_info;

	return err;

}



		memset(&shm_info, 0, sizeof(shm_info));

static int shmctl_shm_info(struct ipc_namespace *ns,

			   struct shm_info *shm_info)

{

	int err = security_shm_shmctl(NULL, SHM_INFO);

	if (!err) {

		memset(shm_info, 0, sizeof(*shm_info));

		down_read(&shm_ids(ns).rwsem);

		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;

		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).rwsem);

		if (copy_to_user(buf, &shm_info, sizeof(shm_info))) {

			err = -EFAULT;

			goto out;

		if (err < 0)

			err = 0;

	}



		err = err < 0 ? 0 : err;

		goto out;

	return err;

}

	case SHM_STAT:

	case IPC_STAT:



static int shmctl_stat(struct ipc_namespace *ns, int shmid,

			int cmd, struct shmid64_ds *tbuf)

{

		struct shmid64_ds tbuf;

	struct shmid_kernel *shp;

	int result;

	int err;



	rcu_read_lock();

	if (cmd == SHM_STAT) {
@@ -955,58 +933,28 @@ static int shmctl_nolock(struct ipc_namespace *ns, int shmid, 
	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;

	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;

	rcu_read_unlock();



		if (copy_shmid_to_user(buf, &tbuf, version))

			err = -EFAULT;

		else

			err = result;

		goto out;

	}

	default:

		return -EINVAL;

	}

	return result;



out_unlock:

	rcu_read_unlock();

out:

	return err;

}



SYSCALL_DEFINE3(shmctl, int, shmid, int, cmd, struct shmid_ds __user *, buf)

static int shmctl_do_lock(struct ipc_namespace *ns, int shmid, int cmd)

{

	struct shmid_kernel *shp;

	int err, version;

	struct ipc_namespace *ns;



	if (cmd < 0 || shmid < 0)

		return -EINVAL;



	version = ipc_parse_version(&cmd);

	ns = current->nsproxy->ipc_ns;



	switch (cmd) {

	case IPC_INFO:

	case SHM_INFO:

	case SHM_STAT:

	case IPC_STAT:

		return shmctl_nolock(ns, shmid, cmd, version, buf);

	case IPC_RMID:

	case IPC_SET:

		return shmctl_down(ns, shmid, cmd, buf, version);

	case SHM_LOCK:

	case SHM_UNLOCK:

	{

	struct file *shm_file;

	int err;



	rcu_read_lock();

	shp = shm_obtain_object_check(ns, shmid);
@@ -1070,10 +1018,6 @@ SYSCALL_DEFINE3(shmctl, int, shmid, int, cmd, struct shmid_ds __user *, buf) 


	fput(shm_file);

	return err;

	}

	default:

		return -EINVAL;

	}



out_unlock0:

	ipc_unlock_object(&shp->shm_perm);
@@ -1082,6 +1026,59 @@ SYSCALL_DEFINE3(shmctl, int, shmid, int, cmd, struct shmid_ds __user *, buf) 
	return err;

}



SYSCALL_DEFINE3(shmctl, int, shmid, int, cmd, struct shmid_ds __user *, buf)

{

	int err, version;

	struct ipc_namespace *ns;

	struct shmid64_ds tbuf;



	if (cmd < 0 || shmid < 0)

		return -EINVAL;



	version = ipc_parse_version(&cmd);

	ns = current->nsproxy->ipc_ns;



	switch (cmd) {

	case IPC_INFO: {

		struct shminfo64 shminfo;

		err = shmctl_ipc_info(ns, &shminfo);

		if (err < 0)

			return err;

		if (copy_shminfo_to_user(buf, &shminfo, version))

			err = -EFAULT;

		return err;

	}

	case SHM_INFO: {

		struct shm_info shm_info;

		err = shmctl_shm_info(ns, &shm_info);

		if (err < 0)

			return err;

		if (copy_to_user(buf, &shm_info, sizeof(shm_info)))

			err = -EFAULT;

		return err;

	}

	case SHM_STAT:

	case IPC_STAT: {

		err = shmctl_stat(ns, shmid, cmd, &tbuf);

		if (err < 0)

			return err;

		if (copy_shmid_to_user(buf, &tbuf, version))

			err = -EFAULT;

		return err;

	}

	case IPC_SET:

		if (copy_shmid_from_user(&tbuf, buf, version))

			return -EFAULT;

	case IPC_RMID:

		return shmctl_down(ns, shmid, cmd, &tbuf);

	case SHM_LOCK:

	case SHM_UNLOCK:

		return shmctl_do_lock(ns, shmid, cmd);

	default:

		return -EINVAL;

	}

}



/*

 * Fix shmaddr, allocate descriptor, map shm, add attach descriptor to lists.

 *