Add a new file descriptor type for IPC shared memory objects and use it to
implement shm_open(2) and shm_unlink(2) in the kernel:
- Each shared memory file descriptor is associated with a swap-backed vm
object which provides the backing store. Each descriptor starts off with
a size of zero, but the size can be altered via ftruncate(2). The shared
memory file descriptors also support fstat(2). read(2), write(2),
ioctl(2), select(2), poll(2), and kevent(2) are not supported on shared
memory file descriptors.
- shm_open(2) and shm_unlink(2) are now implemented as system calls that
manage shared memory file descriptors. The virtual namespace that maps
pathnames to shared memory file descriptors is implemented as a hash
table where the hash key is generated via the 32-bit Fowler/Noll/Vo hash
of the pathname.
- As an extension, the constant 'SHM_ANON' may be specified in place of the
path argument to shm_open(2). In this case, an unnamed shared memory
file descriptor will be created similar to the IPC_PRIVATE key for
shmget(2). Note that the shared memory object can still be shared among
processes by sharing the file descriptor via fork(2) or sendmsg(2), but
it is unnamed. This effectively serves to implement the getmemfd() idea
bandied about the lists several times over the years.
- The backing store for shared memory file descriptors are garbage
collected when they are not referenced by any open file descriptors or
the shm_open(2) virtual namespace.
Submitted by: dillon, peter (previous versions)
Submitted by: rwatson (I based this on his version)
Reviewed by: alc (suggested converting getmemfd() to shm_open())
2008-01-08 21:58:16 +00:00
|
|
|
/*-
|
|
|
|
* Copyright (c) 2003-2006 SPARTA, Inc.
|
2011-09-02 17:40:39 +00:00
|
|
|
* Copyright (c) 2009-2011 Robert N. M. Watson
|
Add a new file descriptor type for IPC shared memory objects and use it to
implement shm_open(2) and shm_unlink(2) in the kernel:
- Each shared memory file descriptor is associated with a swap-backed vm
object which provides the backing store. Each descriptor starts off with
a size of zero, but the size can be altered via ftruncate(2). The shared
memory file descriptors also support fstat(2). read(2), write(2),
ioctl(2), select(2), poll(2), and kevent(2) are not supported on shared
memory file descriptors.
- shm_open(2) and shm_unlink(2) are now implemented as system calls that
manage shared memory file descriptors. The virtual namespace that maps
pathnames to shared memory file descriptors is implemented as a hash
table where the hash key is generated via the 32-bit Fowler/Noll/Vo hash
of the pathname.
- As an extension, the constant 'SHM_ANON' may be specified in place of the
path argument to shm_open(2). In this case, an unnamed shared memory
file descriptor will be created similar to the IPC_PRIVATE key for
shmget(2). Note that the shared memory object can still be shared among
processes by sharing the file descriptor via fork(2) or sendmsg(2), but
it is unnamed. This effectively serves to implement the getmemfd() idea
bandied about the lists several times over the years.
- The backing store for shared memory file descriptors are garbage
collected when they are not referenced by any open file descriptors or
the shm_open(2) virtual namespace.
Submitted by: dillon, peter (previous versions)
Submitted by: rwatson (I based this on his version)
Reviewed by: alc (suggested converting getmemfd() to shm_open())
2008-01-08 21:58:16 +00:00
|
|
|
* All rights reserved.
|
|
|
|
*
|
|
|
|
* This software was developed for the FreeBSD Project in part by Network
|
|
|
|
* Associates Laboratories, the Security Research Division of Network
|
|
|
|
* Associates, Inc. under DARPA/SPAWAR contract N66001-01-C-8035 ("CBOSS"),
|
|
|
|
* as part of the DARPA CHATS research program.
|
|
|
|
*
|
|
|
|
* This software was enhanced by SPARTA ISSO under SPAWAR contract
|
2009-03-08 00:50:37 +00:00
|
|
|
* N66001-04-C-6019 ("SEFOS"). *
|
|
|
|
*
|
|
|
|
* This software was developed at the University of Cambridge Computer
|
|
|
|
* Laboratory with support from a grant from Google, Inc.
|
Add a new file descriptor type for IPC shared memory objects and use it to
implement shm_open(2) and shm_unlink(2) in the kernel:
- Each shared memory file descriptor is associated with a swap-backed vm
object which provides the backing store. Each descriptor starts off with
a size of zero, but the size can be altered via ftruncate(2). The shared
memory file descriptors also support fstat(2). read(2), write(2),
ioctl(2), select(2), poll(2), and kevent(2) are not supported on shared
memory file descriptors.
- shm_open(2) and shm_unlink(2) are now implemented as system calls that
manage shared memory file descriptors. The virtual namespace that maps
pathnames to shared memory file descriptors is implemented as a hash
table where the hash key is generated via the 32-bit Fowler/Noll/Vo hash
of the pathname.
- As an extension, the constant 'SHM_ANON' may be specified in place of the
path argument to shm_open(2). In this case, an unnamed shared memory
file descriptor will be created similar to the IPC_PRIVATE key for
shmget(2). Note that the shared memory object can still be shared among
processes by sharing the file descriptor via fork(2) or sendmsg(2), but
it is unnamed. This effectively serves to implement the getmemfd() idea
bandied about the lists several times over the years.
- The backing store for shared memory file descriptors are garbage
collected when they are not referenced by any open file descriptors or
the shm_open(2) virtual namespace.
Submitted by: dillon, peter (previous versions)
Submitted by: rwatson (I based this on his version)
Reviewed by: alc (suggested converting getmemfd() to shm_open())
2008-01-08 21:58:16 +00:00
|
|
|
*
|
|
|
|
* Redistribution and use in source and binary forms, with or without
|
|
|
|
* modification, are permitted provided that the following conditions
|
|
|
|
* are met:
|
|
|
|
* 1. Redistributions of source code must retain the above copyright
|
|
|
|
* notice, this list of conditions and the following disclaimer.
|
|
|
|
* 2. Redistributions in binary form must reproduce the above copyright
|
|
|
|
* notice, this list of conditions and the following disclaimer in the
|
|
|
|
* documentation and/or other materials provided with the distribution.
|
|
|
|
*
|
|
|
|
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
|
|
|
|
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
|
|
|
|
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
|
|
|
|
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
|
|
|
|
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
|
|
|
|
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
|
|
|
|
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
|
|
|
|
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
|
|
|
|
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
|
|
|
|
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
|
|
|
|
* SUCH DAMAGE.
|
|
|
|
*/
|
|
|
|
|
|
|
|
#include <sys/cdefs.h>
|
|
|
|
__FBSDID("$FreeBSD$");
|
|
|
|
|
|
|
|
#include "opt_mac.h"
|
|
|
|
|
|
|
|
#include <sys/param.h>
|
|
|
|
#include <sys/kernel.h>
|
|
|
|
#include <sys/mman.h>
|
|
|
|
#include <sys/malloc.h>
|
|
|
|
#include <sys/module.h>
|
2009-03-08 00:50:37 +00:00
|
|
|
#include <sys/sdt.h>
|
Add a new file descriptor type for IPC shared memory objects and use it to
implement shm_open(2) and shm_unlink(2) in the kernel:
- Each shared memory file descriptor is associated with a swap-backed vm
object which provides the backing store. Each descriptor starts off with
a size of zero, but the size can be altered via ftruncate(2). The shared
memory file descriptors also support fstat(2). read(2), write(2),
ioctl(2), select(2), poll(2), and kevent(2) are not supported on shared
memory file descriptors.
- shm_open(2) and shm_unlink(2) are now implemented as system calls that
manage shared memory file descriptors. The virtual namespace that maps
pathnames to shared memory file descriptors is implemented as a hash
table where the hash key is generated via the 32-bit Fowler/Noll/Vo hash
of the pathname.
- As an extension, the constant 'SHM_ANON' may be specified in place of the
path argument to shm_open(2). In this case, an unnamed shared memory
file descriptor will be created similar to the IPC_PRIVATE key for
shmget(2). Note that the shared memory object can still be shared among
processes by sharing the file descriptor via fork(2) or sendmsg(2), but
it is unnamed. This effectively serves to implement the getmemfd() idea
bandied about the lists several times over the years.
- The backing store for shared memory file descriptors are garbage
collected when they are not referenced by any open file descriptors or
the shm_open(2) virtual namespace.
Submitted by: dillon, peter (previous versions)
Submitted by: rwatson (I based this on his version)
Reviewed by: alc (suggested converting getmemfd() to shm_open())
2008-01-08 21:58:16 +00:00
|
|
|
#include <sys/systm.h>
|
|
|
|
#include <sys/sysctl.h>
|
|
|
|
|
|
|
|
#include <security/mac/mac_framework.h>
|
|
|
|
#include <security/mac/mac_internal.h>
|
|
|
|
#include <security/mac/mac_policy.h>
|
|
|
|
|
|
|
|
static struct label *
|
|
|
|
mac_posixshm_label_alloc(void)
|
|
|
|
{
|
|
|
|
struct label *label;
|
|
|
|
|
|
|
|
label = mac_labelzone_alloc(M_WAITOK);
|
2009-05-01 21:05:40 +00:00
|
|
|
MAC_POLICY_PERFORM(posixshm_init_label, label);
|
Add a new file descriptor type for IPC shared memory objects and use it to
implement shm_open(2) and shm_unlink(2) in the kernel:
- Each shared memory file descriptor is associated with a swap-backed vm
object which provides the backing store. Each descriptor starts off with
a size of zero, but the size can be altered via ftruncate(2). The shared
memory file descriptors also support fstat(2). read(2), write(2),
ioctl(2), select(2), poll(2), and kevent(2) are not supported on shared
memory file descriptors.
- shm_open(2) and shm_unlink(2) are now implemented as system calls that
manage shared memory file descriptors. The virtual namespace that maps
pathnames to shared memory file descriptors is implemented as a hash
table where the hash key is generated via the 32-bit Fowler/Noll/Vo hash
of the pathname.
- As an extension, the constant 'SHM_ANON' may be specified in place of the
path argument to shm_open(2). In this case, an unnamed shared memory
file descriptor will be created similar to the IPC_PRIVATE key for
shmget(2). Note that the shared memory object can still be shared among
processes by sharing the file descriptor via fork(2) or sendmsg(2), but
it is unnamed. This effectively serves to implement the getmemfd() idea
bandied about the lists several times over the years.
- The backing store for shared memory file descriptors are garbage
collected when they are not referenced by any open file descriptors or
the shm_open(2) virtual namespace.
Submitted by: dillon, peter (previous versions)
Submitted by: rwatson (I based this on his version)
Reviewed by: alc (suggested converting getmemfd() to shm_open())
2008-01-08 21:58:16 +00:00
|
|
|
return (label);
|
|
|
|
}
|
|
|
|
|
|
|
|
void
|
|
|
|
mac_posixshm_init(struct shmfd *shmfd)
|
|
|
|
{
|
|
|
|
|
Introduce two related changes to the TrustedBSD MAC Framework:
(1) Abstract interpreter vnode labeling in execve(2) and mac_execve(2)
so that the general exec code isn't aware of the details of
allocating, copying, and freeing labels, rather, simply passes in
a void pointer to start and stop functions that will be used by
the framework. This change will be MFC'd.
(2) Introduce a new flags field to the MAC_POLICY_SET(9) interface
allowing policies to declare which types of objects require label
allocation, initialization, and destruction, and define a set of
flags covering various supported object types (MPC_OBJECT_PROC,
MPC_OBJECT_VNODE, MPC_OBJECT_INPCB, ...). This change reduces the
overhead of compiling the MAC Framework into the kernel if policies
aren't loaded, or if policies require labels on only a small number
or even no object types. Each time a policy is loaded or unloaded,
we recalculate a mask of labeled object types across all policies
present in the system. Eliminate MAC_ALWAYS_LABEL_MBUF option as it
is no longer required.
MFC after: 1 week ((1) only)
Reviewed by: csjp
Obtained from: TrustedBSD Project
Sponsored by: Apple, Inc.
2008-08-23 15:26:36 +00:00
|
|
|
if (mac_labeled & MPC_OBJECT_POSIXSHM)
|
|
|
|
shmfd->shm_label = mac_posixshm_label_alloc();
|
|
|
|
else
|
|
|
|
shmfd->shm_label = NULL;
|
Add a new file descriptor type for IPC shared memory objects and use it to
implement shm_open(2) and shm_unlink(2) in the kernel:
- Each shared memory file descriptor is associated with a swap-backed vm
object which provides the backing store. Each descriptor starts off with
a size of zero, but the size can be altered via ftruncate(2). The shared
memory file descriptors also support fstat(2). read(2), write(2),
ioctl(2), select(2), poll(2), and kevent(2) are not supported on shared
memory file descriptors.
- shm_open(2) and shm_unlink(2) are now implemented as system calls that
manage shared memory file descriptors. The virtual namespace that maps
pathnames to shared memory file descriptors is implemented as a hash
table where the hash key is generated via the 32-bit Fowler/Noll/Vo hash
of the pathname.
- As an extension, the constant 'SHM_ANON' may be specified in place of the
path argument to shm_open(2). In this case, an unnamed shared memory
file descriptor will be created similar to the IPC_PRIVATE key for
shmget(2). Note that the shared memory object can still be shared among
processes by sharing the file descriptor via fork(2) or sendmsg(2), but
it is unnamed. This effectively serves to implement the getmemfd() idea
bandied about the lists several times over the years.
- The backing store for shared memory file descriptors are garbage
collected when they are not referenced by any open file descriptors or
the shm_open(2) virtual namespace.
Submitted by: dillon, peter (previous versions)
Submitted by: rwatson (I based this on his version)
Reviewed by: alc (suggested converting getmemfd() to shm_open())
2008-01-08 21:58:16 +00:00
|
|
|
}
|
|
|
|
|
|
|
|
static void
|
|
|
|
mac_posixshm_label_free(struct label *label)
|
|
|
|
{
|
|
|
|
|
2009-05-01 21:05:40 +00:00
|
|
|
MAC_POLICY_PERFORM_NOSLEEP(posixshm_destroy_label, label);
|
Add a new file descriptor type for IPC shared memory objects and use it to
implement shm_open(2) and shm_unlink(2) in the kernel:
- Each shared memory file descriptor is associated with a swap-backed vm
object which provides the backing store. Each descriptor starts off with
a size of zero, but the size can be altered via ftruncate(2). The shared
memory file descriptors also support fstat(2). read(2), write(2),
ioctl(2), select(2), poll(2), and kevent(2) are not supported on shared
memory file descriptors.
- shm_open(2) and shm_unlink(2) are now implemented as system calls that
manage shared memory file descriptors. The virtual namespace that maps
pathnames to shared memory file descriptors is implemented as a hash
table where the hash key is generated via the 32-bit Fowler/Noll/Vo hash
of the pathname.
- As an extension, the constant 'SHM_ANON' may be specified in place of the
path argument to shm_open(2). In this case, an unnamed shared memory
file descriptor will be created similar to the IPC_PRIVATE key for
shmget(2). Note that the shared memory object can still be shared among
processes by sharing the file descriptor via fork(2) or sendmsg(2), but
it is unnamed. This effectively serves to implement the getmemfd() idea
bandied about the lists several times over the years.
- The backing store for shared memory file descriptors are garbage
collected when they are not referenced by any open file descriptors or
the shm_open(2) virtual namespace.
Submitted by: dillon, peter (previous versions)
Submitted by: rwatson (I based this on his version)
Reviewed by: alc (suggested converting getmemfd() to shm_open())
2008-01-08 21:58:16 +00:00
|
|
|
mac_labelzone_free(label);
|
|
|
|
}
|
|
|
|
|
|
|
|
void
|
|
|
|
mac_posixshm_destroy(struct shmfd *shmfd)
|
|
|
|
{
|
|
|
|
|
Introduce two related changes to the TrustedBSD MAC Framework:
(1) Abstract interpreter vnode labeling in execve(2) and mac_execve(2)
so that the general exec code isn't aware of the details of
allocating, copying, and freeing labels, rather, simply passes in
a void pointer to start and stop functions that will be used by
the framework. This change will be MFC'd.
(2) Introduce a new flags field to the MAC_POLICY_SET(9) interface
allowing policies to declare which types of objects require label
allocation, initialization, and destruction, and define a set of
flags covering various supported object types (MPC_OBJECT_PROC,
MPC_OBJECT_VNODE, MPC_OBJECT_INPCB, ...). This change reduces the
overhead of compiling the MAC Framework into the kernel if policies
aren't loaded, or if policies require labels on only a small number
or even no object types. Each time a policy is loaded or unloaded,
we recalculate a mask of labeled object types across all policies
present in the system. Eliminate MAC_ALWAYS_LABEL_MBUF option as it
is no longer required.
MFC after: 1 week ((1) only)
Reviewed by: csjp
Obtained from: TrustedBSD Project
Sponsored by: Apple, Inc.
2008-08-23 15:26:36 +00:00
|
|
|
if (shmfd->shm_label != NULL) {
|
|
|
|
mac_posixshm_label_free(shmfd->shm_label);
|
|
|
|
shmfd->shm_label = NULL;
|
|
|
|
}
|
Add a new file descriptor type for IPC shared memory objects and use it to
implement shm_open(2) and shm_unlink(2) in the kernel:
- Each shared memory file descriptor is associated with a swap-backed vm
object which provides the backing store. Each descriptor starts off with
a size of zero, but the size can be altered via ftruncate(2). The shared
memory file descriptors also support fstat(2). read(2), write(2),
ioctl(2), select(2), poll(2), and kevent(2) are not supported on shared
memory file descriptors.
- shm_open(2) and shm_unlink(2) are now implemented as system calls that
manage shared memory file descriptors. The virtual namespace that maps
pathnames to shared memory file descriptors is implemented as a hash
table where the hash key is generated via the 32-bit Fowler/Noll/Vo hash
of the pathname.
- As an extension, the constant 'SHM_ANON' may be specified in place of the
path argument to shm_open(2). In this case, an unnamed shared memory
file descriptor will be created similar to the IPC_PRIVATE key for
shmget(2). Note that the shared memory object can still be shared among
processes by sharing the file descriptor via fork(2) or sendmsg(2), but
it is unnamed. This effectively serves to implement the getmemfd() idea
bandied about the lists several times over the years.
- The backing store for shared memory file descriptors are garbage
collected when they are not referenced by any open file descriptors or
the shm_open(2) virtual namespace.
Submitted by: dillon, peter (previous versions)
Submitted by: rwatson (I based this on his version)
Reviewed by: alc (suggested converting getmemfd() to shm_open())
2008-01-08 21:58:16 +00:00
|
|
|
}
|
|
|
|
|
|
|
|
void
|
|
|
|
mac_posixshm_create(struct ucred *cred, struct shmfd *shmfd)
|
|
|
|
{
|
|
|
|
|
2009-05-01 21:05:40 +00:00
|
|
|
MAC_POLICY_PERFORM_NOSLEEP(posixshm_create, cred, shmfd,
|
|
|
|
shmfd->shm_label);
|
Add a new file descriptor type for IPC shared memory objects and use it to
implement shm_open(2) and shm_unlink(2) in the kernel:
- Each shared memory file descriptor is associated with a swap-backed vm
object which provides the backing store. Each descriptor starts off with
a size of zero, but the size can be altered via ftruncate(2). The shared
memory file descriptors also support fstat(2). read(2), write(2),
ioctl(2), select(2), poll(2), and kevent(2) are not supported on shared
memory file descriptors.
- shm_open(2) and shm_unlink(2) are now implemented as system calls that
manage shared memory file descriptors. The virtual namespace that maps
pathnames to shared memory file descriptors is implemented as a hash
table where the hash key is generated via the 32-bit Fowler/Noll/Vo hash
of the pathname.
- As an extension, the constant 'SHM_ANON' may be specified in place of the
path argument to shm_open(2). In this case, an unnamed shared memory
file descriptor will be created similar to the IPC_PRIVATE key for
shmget(2). Note that the shared memory object can still be shared among
processes by sharing the file descriptor via fork(2) or sendmsg(2), but
it is unnamed. This effectively serves to implement the getmemfd() idea
bandied about the lists several times over the years.
- The backing store for shared memory file descriptors are garbage
collected when they are not referenced by any open file descriptors or
the shm_open(2) virtual namespace.
Submitted by: dillon, peter (previous versions)
Submitted by: rwatson (I based this on his version)
Reviewed by: alc (suggested converting getmemfd() to shm_open())
2008-01-08 21:58:16 +00:00
|
|
|
}
|
|
|
|
|
2011-09-02 17:40:39 +00:00
|
|
|
MAC_CHECK_PROBE_DEFINE2(posixshm_check_create, "struct ucred *",
|
|
|
|
"const char *");
|
|
|
|
|
|
|
|
int
|
|
|
|
mac_posixshm_check_create(struct ucred *cred, const char *path)
|
|
|
|
{
|
|
|
|
int error;
|
|
|
|
|
|
|
|
MAC_POLICY_CHECK_NOSLEEP(posixshm_check_create, cred, path);
|
|
|
|
MAC_CHECK_PROBE2(posixshm_check_create, error, cred, path);
|
|
|
|
|
|
|
|
return (error);
|
|
|
|
}
|
|
|
|
|
2009-03-08 00:50:37 +00:00
|
|
|
MAC_CHECK_PROBE_DEFINE4(posixshm_check_mmap, "struct ucred *",
|
|
|
|
"struct shmfd *", "int", "int");
|
|
|
|
|
Add a new file descriptor type for IPC shared memory objects and use it to
implement shm_open(2) and shm_unlink(2) in the kernel:
- Each shared memory file descriptor is associated with a swap-backed vm
object which provides the backing store. Each descriptor starts off with
a size of zero, but the size can be altered via ftruncate(2). The shared
memory file descriptors also support fstat(2). read(2), write(2),
ioctl(2), select(2), poll(2), and kevent(2) are not supported on shared
memory file descriptors.
- shm_open(2) and shm_unlink(2) are now implemented as system calls that
manage shared memory file descriptors. The virtual namespace that maps
pathnames to shared memory file descriptors is implemented as a hash
table where the hash key is generated via the 32-bit Fowler/Noll/Vo hash
of the pathname.
- As an extension, the constant 'SHM_ANON' may be specified in place of the
path argument to shm_open(2). In this case, an unnamed shared memory
file descriptor will be created similar to the IPC_PRIVATE key for
shmget(2). Note that the shared memory object can still be shared among
processes by sharing the file descriptor via fork(2) or sendmsg(2), but
it is unnamed. This effectively serves to implement the getmemfd() idea
bandied about the lists several times over the years.
- The backing store for shared memory file descriptors are garbage
collected when they are not referenced by any open file descriptors or
the shm_open(2) virtual namespace.
Submitted by: dillon, peter (previous versions)
Submitted by: rwatson (I based this on his version)
Reviewed by: alc (suggested converting getmemfd() to shm_open())
2008-01-08 21:58:16 +00:00
|
|
|
int
|
|
|
|
mac_posixshm_check_mmap(struct ucred *cred, struct shmfd *shmfd, int prot,
|
|
|
|
int flags)
|
|
|
|
{
|
|
|
|
int error;
|
|
|
|
|
2009-05-01 21:05:40 +00:00
|
|
|
MAC_POLICY_CHECK_NOSLEEP(posixshm_check_mmap, cred, shmfd,
|
|
|
|
shmfd->shm_label, prot, flags);
|
2009-03-08 00:50:37 +00:00
|
|
|
MAC_CHECK_PROBE4(posixshm_check_mmap, error, cred, shmfd, prot,
|
|
|
|
flags);
|
Add a new file descriptor type for IPC shared memory objects and use it to
implement shm_open(2) and shm_unlink(2) in the kernel:
- Each shared memory file descriptor is associated with a swap-backed vm
object which provides the backing store. Each descriptor starts off with
a size of zero, but the size can be altered via ftruncate(2). The shared
memory file descriptors also support fstat(2). read(2), write(2),
ioctl(2), select(2), poll(2), and kevent(2) are not supported on shared
memory file descriptors.
- shm_open(2) and shm_unlink(2) are now implemented as system calls that
manage shared memory file descriptors. The virtual namespace that maps
pathnames to shared memory file descriptors is implemented as a hash
table where the hash key is generated via the 32-bit Fowler/Noll/Vo hash
of the pathname.
- As an extension, the constant 'SHM_ANON' may be specified in place of the
path argument to shm_open(2). In this case, an unnamed shared memory
file descriptor will be created similar to the IPC_PRIVATE key for
shmget(2). Note that the shared memory object can still be shared among
processes by sharing the file descriptor via fork(2) or sendmsg(2), but
it is unnamed. This effectively serves to implement the getmemfd() idea
bandied about the lists several times over the years.
- The backing store for shared memory file descriptors are garbage
collected when they are not referenced by any open file descriptors or
the shm_open(2) virtual namespace.
Submitted by: dillon, peter (previous versions)
Submitted by: rwatson (I based this on his version)
Reviewed by: alc (suggested converting getmemfd() to shm_open())
2008-01-08 21:58:16 +00:00
|
|
|
|
|
|
|
return (error);
|
|
|
|
}
|
|
|
|
|
2011-09-02 17:40:39 +00:00
|
|
|
MAC_CHECK_PROBE_DEFINE3(posixshm_check_open, "struct ucred *",
|
2013-10-01 15:40:27 +00:00
|
|
|
"struct shmfd *", "accmode_t");
|
2009-03-08 00:50:37 +00:00
|
|
|
|
Add a new file descriptor type for IPC shared memory objects and use it to
implement shm_open(2) and shm_unlink(2) in the kernel:
- Each shared memory file descriptor is associated with a swap-backed vm
object which provides the backing store. Each descriptor starts off with
a size of zero, but the size can be altered via ftruncate(2). The shared
memory file descriptors also support fstat(2). read(2), write(2),
ioctl(2), select(2), poll(2), and kevent(2) are not supported on shared
memory file descriptors.
- shm_open(2) and shm_unlink(2) are now implemented as system calls that
manage shared memory file descriptors. The virtual namespace that maps
pathnames to shared memory file descriptors is implemented as a hash
table where the hash key is generated via the 32-bit Fowler/Noll/Vo hash
of the pathname.
- As an extension, the constant 'SHM_ANON' may be specified in place of the
path argument to shm_open(2). In this case, an unnamed shared memory
file descriptor will be created similar to the IPC_PRIVATE key for
shmget(2). Note that the shared memory object can still be shared among
processes by sharing the file descriptor via fork(2) or sendmsg(2), but
it is unnamed. This effectively serves to implement the getmemfd() idea
bandied about the lists several times over the years.
- The backing store for shared memory file descriptors are garbage
collected when they are not referenced by any open file descriptors or
the shm_open(2) virtual namespace.
Submitted by: dillon, peter (previous versions)
Submitted by: rwatson (I based this on his version)
Reviewed by: alc (suggested converting getmemfd() to shm_open())
2008-01-08 21:58:16 +00:00
|
|
|
int
|
2011-09-02 17:40:39 +00:00
|
|
|
mac_posixshm_check_open(struct ucred *cred, struct shmfd *shmfd,
|
|
|
|
accmode_t accmode)
|
Add a new file descriptor type for IPC shared memory objects and use it to
implement shm_open(2) and shm_unlink(2) in the kernel:
- Each shared memory file descriptor is associated with a swap-backed vm
object which provides the backing store. Each descriptor starts off with
a size of zero, but the size can be altered via ftruncate(2). The shared
memory file descriptors also support fstat(2). read(2), write(2),
ioctl(2), select(2), poll(2), and kevent(2) are not supported on shared
memory file descriptors.
- shm_open(2) and shm_unlink(2) are now implemented as system calls that
manage shared memory file descriptors. The virtual namespace that maps
pathnames to shared memory file descriptors is implemented as a hash
table where the hash key is generated via the 32-bit Fowler/Noll/Vo hash
of the pathname.
- As an extension, the constant 'SHM_ANON' may be specified in place of the
path argument to shm_open(2). In this case, an unnamed shared memory
file descriptor will be created similar to the IPC_PRIVATE key for
shmget(2). Note that the shared memory object can still be shared among
processes by sharing the file descriptor via fork(2) or sendmsg(2), but
it is unnamed. This effectively serves to implement the getmemfd() idea
bandied about the lists several times over the years.
- The backing store for shared memory file descriptors are garbage
collected when they are not referenced by any open file descriptors or
the shm_open(2) virtual namespace.
Submitted by: dillon, peter (previous versions)
Submitted by: rwatson (I based this on his version)
Reviewed by: alc (suggested converting getmemfd() to shm_open())
2008-01-08 21:58:16 +00:00
|
|
|
{
|
|
|
|
int error;
|
|
|
|
|
2009-05-01 21:05:40 +00:00
|
|
|
MAC_POLICY_CHECK_NOSLEEP(posixshm_check_open, cred, shmfd,
|
2011-09-02 17:40:39 +00:00
|
|
|
shmfd->shm_label, accmode);
|
|
|
|
MAC_CHECK_PROBE3(posixshm_check_open, error, cred, shmfd, accmode);
|
Add a new file descriptor type for IPC shared memory objects and use it to
implement shm_open(2) and shm_unlink(2) in the kernel:
- Each shared memory file descriptor is associated with a swap-backed vm
object which provides the backing store. Each descriptor starts off with
a size of zero, but the size can be altered via ftruncate(2). The shared
memory file descriptors also support fstat(2). read(2), write(2),
ioctl(2), select(2), poll(2), and kevent(2) are not supported on shared
memory file descriptors.
- shm_open(2) and shm_unlink(2) are now implemented as system calls that
manage shared memory file descriptors. The virtual namespace that maps
pathnames to shared memory file descriptors is implemented as a hash
table where the hash key is generated via the 32-bit Fowler/Noll/Vo hash
of the pathname.
- As an extension, the constant 'SHM_ANON' may be specified in place of the
path argument to shm_open(2). In this case, an unnamed shared memory
file descriptor will be created similar to the IPC_PRIVATE key for
shmget(2). Note that the shared memory object can still be shared among
processes by sharing the file descriptor via fork(2) or sendmsg(2), but
it is unnamed. This effectively serves to implement the getmemfd() idea
bandied about the lists several times over the years.
- The backing store for shared memory file descriptors are garbage
collected when they are not referenced by any open file descriptors or
the shm_open(2) virtual namespace.
Submitted by: dillon, peter (previous versions)
Submitted by: rwatson (I based this on his version)
Reviewed by: alc (suggested converting getmemfd() to shm_open())
2008-01-08 21:58:16 +00:00
|
|
|
|
|
|
|
return (error);
|
|
|
|
}
|
|
|
|
|
2009-03-08 00:50:37 +00:00
|
|
|
MAC_CHECK_PROBE_DEFINE3(posixshm_check_stat, "struct ucred *",
|
|
|
|
"struct ucred *", "struct shmfd *");
|
|
|
|
|
Add a new file descriptor type for IPC shared memory objects and use it to
implement shm_open(2) and shm_unlink(2) in the kernel:
- Each shared memory file descriptor is associated with a swap-backed vm
object which provides the backing store. Each descriptor starts off with
a size of zero, but the size can be altered via ftruncate(2). The shared
memory file descriptors also support fstat(2). read(2), write(2),
ioctl(2), select(2), poll(2), and kevent(2) are not supported on shared
memory file descriptors.
- shm_open(2) and shm_unlink(2) are now implemented as system calls that
manage shared memory file descriptors. The virtual namespace that maps
pathnames to shared memory file descriptors is implemented as a hash
table where the hash key is generated via the 32-bit Fowler/Noll/Vo hash
of the pathname.
- As an extension, the constant 'SHM_ANON' may be specified in place of the
path argument to shm_open(2). In this case, an unnamed shared memory
file descriptor will be created similar to the IPC_PRIVATE key for
shmget(2). Note that the shared memory object can still be shared among
processes by sharing the file descriptor via fork(2) or sendmsg(2), but
it is unnamed. This effectively serves to implement the getmemfd() idea
bandied about the lists several times over the years.
- The backing store for shared memory file descriptors are garbage
collected when they are not referenced by any open file descriptors or
the shm_open(2) virtual namespace.
Submitted by: dillon, peter (previous versions)
Submitted by: rwatson (I based this on his version)
Reviewed by: alc (suggested converting getmemfd() to shm_open())
2008-01-08 21:58:16 +00:00
|
|
|
int
|
|
|
|
mac_posixshm_check_stat(struct ucred *active_cred, struct ucred *file_cred,
|
|
|
|
struct shmfd *shmfd)
|
|
|
|
{
|
|
|
|
int error;
|
|
|
|
|
2009-05-01 21:05:40 +00:00
|
|
|
MAC_POLICY_CHECK_NOSLEEP(posixshm_check_stat, active_cred, file_cred,
|
|
|
|
shmfd, shmfd->shm_label);
|
2009-03-08 00:50:37 +00:00
|
|
|
MAC_CHECK_PROBE3(posixshm_check_stat, error, active_cred, file_cred,
|
|
|
|
shmfd);
|
Add a new file descriptor type for IPC shared memory objects and use it to
implement shm_open(2) and shm_unlink(2) in the kernel:
- Each shared memory file descriptor is associated with a swap-backed vm
object which provides the backing store. Each descriptor starts off with
a size of zero, but the size can be altered via ftruncate(2). The shared
memory file descriptors also support fstat(2). read(2), write(2),
ioctl(2), select(2), poll(2), and kevent(2) are not supported on shared
memory file descriptors.
- shm_open(2) and shm_unlink(2) are now implemented as system calls that
manage shared memory file descriptors. The virtual namespace that maps
pathnames to shared memory file descriptors is implemented as a hash
table where the hash key is generated via the 32-bit Fowler/Noll/Vo hash
of the pathname.
- As an extension, the constant 'SHM_ANON' may be specified in place of the
path argument to shm_open(2). In this case, an unnamed shared memory
file descriptor will be created similar to the IPC_PRIVATE key for
shmget(2). Note that the shared memory object can still be shared among
processes by sharing the file descriptor via fork(2) or sendmsg(2), but
it is unnamed. This effectively serves to implement the getmemfd() idea
bandied about the lists several times over the years.
- The backing store for shared memory file descriptors are garbage
collected when they are not referenced by any open file descriptors or
the shm_open(2) virtual namespace.
Submitted by: dillon, peter (previous versions)
Submitted by: rwatson (I based this on his version)
Reviewed by: alc (suggested converting getmemfd() to shm_open())
2008-01-08 21:58:16 +00:00
|
|
|
|
|
|
|
return (error);
|
|
|
|
}
|
|
|
|
|
2009-03-08 00:50:37 +00:00
|
|
|
MAC_CHECK_PROBE_DEFINE3(posixshm_check_truncate, "struct ucred *",
|
|
|
|
"struct ucred *", "struct shmfd *");
|
|
|
|
|
Add a new file descriptor type for IPC shared memory objects and use it to
implement shm_open(2) and shm_unlink(2) in the kernel:
- Each shared memory file descriptor is associated with a swap-backed vm
object which provides the backing store. Each descriptor starts off with
a size of zero, but the size can be altered via ftruncate(2). The shared
memory file descriptors also support fstat(2). read(2), write(2),
ioctl(2), select(2), poll(2), and kevent(2) are not supported on shared
memory file descriptors.
- shm_open(2) and shm_unlink(2) are now implemented as system calls that
manage shared memory file descriptors. The virtual namespace that maps
pathnames to shared memory file descriptors is implemented as a hash
table where the hash key is generated via the 32-bit Fowler/Noll/Vo hash
of the pathname.
- As an extension, the constant 'SHM_ANON' may be specified in place of the
path argument to shm_open(2). In this case, an unnamed shared memory
file descriptor will be created similar to the IPC_PRIVATE key for
shmget(2). Note that the shared memory object can still be shared among
processes by sharing the file descriptor via fork(2) or sendmsg(2), but
it is unnamed. This effectively serves to implement the getmemfd() idea
bandied about the lists several times over the years.
- The backing store for shared memory file descriptors are garbage
collected when they are not referenced by any open file descriptors or
the shm_open(2) virtual namespace.
Submitted by: dillon, peter (previous versions)
Submitted by: rwatson (I based this on his version)
Reviewed by: alc (suggested converting getmemfd() to shm_open())
2008-01-08 21:58:16 +00:00
|
|
|
int
|
|
|
|
mac_posixshm_check_truncate(struct ucred *active_cred, struct ucred *file_cred,
|
|
|
|
struct shmfd *shmfd)
|
|
|
|
{
|
|
|
|
int error;
|
|
|
|
|
2009-05-01 21:05:40 +00:00
|
|
|
MAC_POLICY_CHECK_NOSLEEP(posixshm_check_truncate, active_cred,
|
|
|
|
file_cred, shmfd, shmfd->shm_label);
|
2009-03-08 00:50:37 +00:00
|
|
|
MAC_CHECK_PROBE3(posixshm_check_truncate, error, active_cred,
|
|
|
|
file_cred, shmfd);
|
Add a new file descriptor type for IPC shared memory objects and use it to
implement shm_open(2) and shm_unlink(2) in the kernel:
- Each shared memory file descriptor is associated with a swap-backed vm
object which provides the backing store. Each descriptor starts off with
a size of zero, but the size can be altered via ftruncate(2). The shared
memory file descriptors also support fstat(2). read(2), write(2),
ioctl(2), select(2), poll(2), and kevent(2) are not supported on shared
memory file descriptors.
- shm_open(2) and shm_unlink(2) are now implemented as system calls that
manage shared memory file descriptors. The virtual namespace that maps
pathnames to shared memory file descriptors is implemented as a hash
table where the hash key is generated via the 32-bit Fowler/Noll/Vo hash
of the pathname.
- As an extension, the constant 'SHM_ANON' may be specified in place of the
path argument to shm_open(2). In this case, an unnamed shared memory
file descriptor will be created similar to the IPC_PRIVATE key for
shmget(2). Note that the shared memory object can still be shared among
processes by sharing the file descriptor via fork(2) or sendmsg(2), but
it is unnamed. This effectively serves to implement the getmemfd() idea
bandied about the lists several times over the years.
- The backing store for shared memory file descriptors are garbage
collected when they are not referenced by any open file descriptors or
the shm_open(2) virtual namespace.
Submitted by: dillon, peter (previous versions)
Submitted by: rwatson (I based this on his version)
Reviewed by: alc (suggested converting getmemfd() to shm_open())
2008-01-08 21:58:16 +00:00
|
|
|
|
|
|
|
return (error);
|
|
|
|
}
|
|
|
|
|
2009-03-08 00:50:37 +00:00
|
|
|
MAC_CHECK_PROBE_DEFINE2(posixshm_check_unlink, "struct ucred *",
|
|
|
|
"struct shmfd *");
|
|
|
|
|
Add a new file descriptor type for IPC shared memory objects and use it to
implement shm_open(2) and shm_unlink(2) in the kernel:
- Each shared memory file descriptor is associated with a swap-backed vm
object which provides the backing store. Each descriptor starts off with
a size of zero, but the size can be altered via ftruncate(2). The shared
memory file descriptors also support fstat(2). read(2), write(2),
ioctl(2), select(2), poll(2), and kevent(2) are not supported on shared
memory file descriptors.
- shm_open(2) and shm_unlink(2) are now implemented as system calls that
manage shared memory file descriptors. The virtual namespace that maps
pathnames to shared memory file descriptors is implemented as a hash
table where the hash key is generated via the 32-bit Fowler/Noll/Vo hash
of the pathname.
- As an extension, the constant 'SHM_ANON' may be specified in place of the
path argument to shm_open(2). In this case, an unnamed shared memory
file descriptor will be created similar to the IPC_PRIVATE key for
shmget(2). Note that the shared memory object can still be shared among
processes by sharing the file descriptor via fork(2) or sendmsg(2), but
it is unnamed. This effectively serves to implement the getmemfd() idea
bandied about the lists several times over the years.
- The backing store for shared memory file descriptors are garbage
collected when they are not referenced by any open file descriptors or
the shm_open(2) virtual namespace.
Submitted by: dillon, peter (previous versions)
Submitted by: rwatson (I based this on his version)
Reviewed by: alc (suggested converting getmemfd() to shm_open())
2008-01-08 21:58:16 +00:00
|
|
|
int
|
|
|
|
mac_posixshm_check_unlink(struct ucred *cred, struct shmfd *shmfd)
|
|
|
|
{
|
|
|
|
int error;
|
|
|
|
|
2009-05-01 21:05:40 +00:00
|
|
|
MAC_POLICY_CHECK_NOSLEEP(posixshm_check_unlink, cred, shmfd,
|
Rework MAC Framework synchronization in a number of ways in order to
improve performance:
- Eliminate custom reference count and condition variable to monitor
threads entering the framework, as this had both significant overhead
and behaved badly in the face of contention.
- Replace reference count with two locks: an rwlock and an sx lock,
which will be read-acquired by threads entering the framework
depending on whether a give policy entry point is permitted to sleep
or not.
- Replace previous mutex locking of the reference count for exclusive
access with write acquiring of both the policy list sx and rw locks,
which occurs only when policies are attached or detached.
- Do a lockless read of the dynamic policy list head before acquiring
any locks in order to reduce overhead when no dynamic policies are
loaded; this a race we can afford to lose.
- For every policy entry point invocation, decide whether sleeping is
permitted, and if not, use a _NOSLEEP() variant of the composition
macros, which will use the rwlock instead of the sxlock. In some
cases, we decide which to use based on allocation flags passed to the
MAC Framework entry point.
As with the move to rwlocks/rmlocks in pfil, this may trigger witness
warnings, but these should (generally) be false positives as all
acquisition of the locks is for read with two very narrow exceptions
for policy load/unload, and those code blocks should never acquire
other locks.
Sponsored by: Google, Inc.
Obtained from: TrustedBSD Project
Discussed with: csjp (idea, not specific patch)
2009-03-14 16:06:06 +00:00
|
|
|
shmfd->shm_label);
|
2009-03-08 00:50:37 +00:00
|
|
|
MAC_CHECK_PROBE2(posixshm_check_unlink, error, cred, shmfd);
|
Add a new file descriptor type for IPC shared memory objects and use it to
implement shm_open(2) and shm_unlink(2) in the kernel:
- Each shared memory file descriptor is associated with a swap-backed vm
object which provides the backing store. Each descriptor starts off with
a size of zero, but the size can be altered via ftruncate(2). The shared
memory file descriptors also support fstat(2). read(2), write(2),
ioctl(2), select(2), poll(2), and kevent(2) are not supported on shared
memory file descriptors.
- shm_open(2) and shm_unlink(2) are now implemented as system calls that
manage shared memory file descriptors. The virtual namespace that maps
pathnames to shared memory file descriptors is implemented as a hash
table where the hash key is generated via the 32-bit Fowler/Noll/Vo hash
of the pathname.
- As an extension, the constant 'SHM_ANON' may be specified in place of the
path argument to shm_open(2). In this case, an unnamed shared memory
file descriptor will be created similar to the IPC_PRIVATE key for
shmget(2). Note that the shared memory object can still be shared among
processes by sharing the file descriptor via fork(2) or sendmsg(2), but
it is unnamed. This effectively serves to implement the getmemfd() idea
bandied about the lists several times over the years.
- The backing store for shared memory file descriptors are garbage
collected when they are not referenced by any open file descriptors or
the shm_open(2) virtual namespace.
Submitted by: dillon, peter (previous versions)
Submitted by: rwatson (I based this on his version)
Reviewed by: alc (suggested converting getmemfd() to shm_open())
2008-01-08 21:58:16 +00:00
|
|
|
|
|
|
|
return (error);
|
|
|
|
}
|
2011-08-16 20:07:47 +00:00
|
|
|
|
|
|
|
MAC_CHECK_PROBE_DEFINE3(posixshm_check_setmode, "struct ucred *",
|
|
|
|
"struct shmfd *", "mode_t");
|
|
|
|
|
|
|
|
int
|
|
|
|
mac_posixshm_check_setmode(struct ucred *cred, struct shmfd *shmfd, mode_t mode)
|
|
|
|
{
|
|
|
|
int error;
|
|
|
|
|
|
|
|
MAC_POLICY_CHECK_NOSLEEP(posixshm_check_setmode, cred, shmfd,
|
|
|
|
shmfd->shm_label, mode);
|
|
|
|
MAC_CHECK_PROBE3(posixshm_check_setmode, error, cred, shmfd, mode);
|
|
|
|
|
|
|
|
return (error);
|
|
|
|
}
|
|
|
|
|
|
|
|
MAC_CHECK_PROBE_DEFINE4(posixshm_check_setowner, "struct ucred *",
|
|
|
|
"struct shmfd *", "uid_t", "gid_t");
|
|
|
|
|
|
|
|
int
|
|
|
|
mac_posixshm_check_setowner(struct ucred *cred, struct shmfd *shmfd, uid_t uid,
|
|
|
|
gid_t gid)
|
|
|
|
{
|
|
|
|
int error;
|
|
|
|
|
|
|
|
MAC_POLICY_CHECK_NOSLEEP(posixshm_check_setowner, cred, shmfd,
|
|
|
|
shmfd->shm_label, uid, gid);
|
|
|
|
MAC_CHECK_PROBE4(posixshm_check_setowner, error, cred, shmfd,
|
|
|
|
uid, gid);
|
|
|
|
|
|
|
|
return (error);
|
|
|
|
}
|
2013-08-21 17:45:00 +00:00
|
|
|
|
|
|
|
MAC_CHECK_PROBE_DEFINE3(posixshm_check_read, "struct ucred *",
|
|
|
|
"struct ucred *", "struct shmfd *");
|
|
|
|
|
|
|
|
int
|
|
|
|
mac_posixshm_check_read(struct ucred *active_cred, struct ucred *file_cred,
|
|
|
|
struct shmfd *shmfd)
|
|
|
|
{
|
|
|
|
int error;
|
|
|
|
|
|
|
|
MAC_POLICY_CHECK_NOSLEEP(posixshm_check_read, active_cred,
|
|
|
|
file_cred, shmfd, shmfd->shm_label);
|
|
|
|
MAC_CHECK_PROBE3(posixshm_check_read, error, active_cred,
|
|
|
|
file_cred, shmfd);
|
|
|
|
|
|
|
|
return (error);
|
|
|
|
}
|
|
|
|
|
|
|
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MAC_CHECK_PROBE_DEFINE3(posixshm_check_write, "struct ucred *",
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"struct ucred *", "struct shmfd *");
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int
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mac_posixshm_check_write(struct ucred *active_cred, struct ucred *file_cred,
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struct shmfd *shmfd)
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{
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int error;
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MAC_POLICY_CHECK_NOSLEEP(posixshm_check_write, active_cred,
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file_cred, shmfd, shmfd->shm_label);
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MAC_CHECK_PROBE3(posixshm_check_write, error, active_cred,
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file_cred, shmfd);
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return (error);
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}
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