[PATCH v5 0/3] RFC: Secure Memory Allocation Framework

[PATCH v5 0/3] RFC: Secure Memory Allocation Framework

[Benjamin Gaignard]

version 5 changes:
 - rebased on kernel 4.3-rc6
 - rework locking schema and make handle status use an atomic_t
 - add a fake secure module to allow performing tests without trusted
   environment

version 4 changes:
 - rebased on kernel 4.3-rc3
 - fix missing EXPORT_SYMBOL for smaf_create_handle()

version 3 changes:
 - Remove ioctl for allocator selection instead provide the name of
   the targeted allocator with allocation request.
   Selecting allocator from userland isn't the prefered way of working
   but is needed when the first user of the buffer is a software component.
 - Fix issues in case of error while creating smaf handle.
 - Fix module license.
 - Update libsmaf and tests to care of the SMAF API evolution
   https://git.linaro.org/people/benjamin.gaignard/libsmaf.git

version 2 changes:
 - Add one ioctl to allow allocator selection from userspace.
   This is required for the uses case where the first user of
   the buffer is a software IP which can't perform dma_buf attachement.
 - Add name and ranking to allocator structure to be able to sort them.
 - Create a tiny library to test SMAF:
   https://git.linaro.org/people/benjamin.gaignard/libsmaf.git
 - Fix one issue when try to secure buffer without secure module registered

The outcome of the previous RFC about how do secure data path was the need
of a secure memory allocator (https://lkml.org/lkml/2015/5/5/551)

SMAF goal is to provide a framework that allow allocating and securing
memory by using dma_buf. Each platform have it own way to perform those two
features so SMAF design allow to register helper modules to perform them.

To be sure to select the best allocation method for devices SMAF implement
deferred allocation mechanism: memory allocation is only done when the first
device effectively required it.
Allocator modules have to implement a match() to let SMAF know if they are
compatibles with devices needs.
This patch set provide an example of allocator module which use
dma_{alloc/free/mmap}_attrs() and check if at least one device have
coherent_dma_mask set to DMA_BIT_MASK(32) in match function. 
I have named smaf-cma.c like it is done for drm_gem_cma_helper.c even if 
a better name could be found for this file.

Secure modules are responsibles of granting and revoking devices access rights
on the memory. Secure module is also called to check if CPU map memory into
kernel and user address spaces.
An example of secure module implementation can be found here:
http://git.linaro.org/people/benjamin.gaignard/optee-sdp.git
This code isn't yet part of the patch set because it depends on generic TEE
which is still under discussion (https://lwn.net/Articles/644646/)

For allocation part of SMAF code I get inspirated by Sumit Semwal work about
constraint aware allocator.


Benjamin Gaignard (3):
  create SMAF module
  SMAF: add CMA allocator
  SMAF: add fake secure module

 drivers/Kconfig                |   2 +
 drivers/Makefile               |   1 +
 drivers/smaf/Kconfig           |  17 +
 drivers/smaf/Makefile          |   3 +
 drivers/smaf/smaf-cma.c        | 200 +++++++++++
 drivers/smaf/smaf-core.c       | 753 +++++++++++++++++++++++++++++++++++++++++
 drivers/smaf/smaf-fakesecure.c |  92 +++++
 include/linux/smaf-allocator.h |  54 +++
 include/linux/smaf-secure.h    |  75 ++++
 include/uapi/linux/smaf.h      |  52 +++
 10 files changed, 1249 insertions(+)
 create mode 100644 drivers/smaf/Kconfig
 create mode 100644 drivers/smaf/Makefile
 create mode 100644 drivers/smaf/smaf-cma.c
 create mode 100644 drivers/smaf/smaf-core.c
 create mode 100644 drivers/smaf/smaf-fakesecure.c
 create mode 100644 include/linux/smaf-allocator.h
 create mode 100644 include/linux/smaf-secure.h
 create mode 100644 include/uapi/linux/smaf.h

-- 
1.9.1

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[PATCH v5 1/3] create SMAF module

[Benjamin Gaignard]

Secure Memory Allocation Framework goal is to be able
to allocate memory that can be securing.
There is so much ways to allocate and securing memory that SMAF
doesn't do it by itself but need help of additional modules.
To be sure to use the correct allocation method SMAF implement
deferred allocation (i.e. allocate memory when only really needed)

Allocation modules (smaf-alloctor.h):
SMAF could manage with multiple allocation modules at same time.
To select the good one SMAF call match() to be sure that a module
can allocate memory for a given list of devices. It is to the module
to check if the devices are compatible or not with it allocation
method.

Securing module (smaf-secure.h):
The way of how securing memory it is done is platform specific.
Secure module is responsible of grant/revoke memory access.

Signed-off-by: Benjamin Gaignard <benjamin.gaignard@linaro.org>
---
 drivers/Kconfig                |   2 +
 drivers/Makefile               |   1 +
 drivers/smaf/Kconfig           |   5 +
 drivers/smaf/Makefile          |   1 +
 drivers/smaf/smaf-core.c       | 753 +++++++++++++++++++++++++++++++++++++++++
 include/linux/smaf-allocator.h |  54 +++
 include/linux/smaf-secure.h    |  75 ++++
 include/uapi/linux/smaf.h      |  52 +++
 8 files changed, 943 insertions(+)
 create mode 100644 drivers/smaf/Kconfig
 create mode 100644 drivers/smaf/Makefile
 create mode 100644 drivers/smaf/smaf-core.c
 create mode 100644 include/linux/smaf-allocator.h
 create mode 100644 include/linux/smaf-secure.h
 create mode 100644 include/uapi/linux/smaf.h

diff --git a/drivers/Kconfig b/drivers/Kconfig
index 46b4a8e..a488c20 100644
--- a/drivers/Kconfig
+++ b/drivers/Kconfig
@@ -188,4 +188,6 @@ source "drivers/nvdimm/Kconfig"
 
 source "drivers/nvmem/Kconfig"
 
+source "drivers/smaf/Kconfig"
+
 endmenu
diff --git a/drivers/Makefile b/drivers/Makefile
index b250b36..693390b 100644
--- a/drivers/Makefile
+++ b/drivers/Makefile
@@ -167,3 +167,4 @@ obj-$(CONFIG_THUNDERBOLT)	+= thunderbolt/
 obj-$(CONFIG_CORESIGHT)		+= hwtracing/coresight/
 obj-$(CONFIG_ANDROID)		+= android/
 obj-$(CONFIG_NVMEM)		+= nvmem/
+obj-$(CONFIG_SMAF) 		+= smaf/
diff --git a/drivers/smaf/Kconfig b/drivers/smaf/Kconfig
new file mode 100644
index 0000000..d36651a
--- /dev/null
+++ b/drivers/smaf/Kconfig
@@ -0,0 +1,5 @@
+config SMAF
+	tristate "Secure Memory Allocation Framework"
+	depends on DMA_SHARED_BUFFER
+	help
+	  Choose this option to enable Secure Memory Allocation Framework
diff --git a/drivers/smaf/Makefile b/drivers/smaf/Makefile
new file mode 100644
index 0000000..40cd882
--- /dev/null
+++ b/drivers/smaf/Makefile
@@ -0,0 +1 @@
+obj-$(CONFIG_SMAF) += smaf-core.o
diff --git a/drivers/smaf/smaf-core.c b/drivers/smaf/smaf-core.c
new file mode 100644
index 0000000..1d9a55e
--- /dev/null
+++ b/drivers/smaf/smaf-core.c
@@ -0,0 +1,753 @@
+/*
+ * smaf.c
+ *
+ * Copyright (C) Linaro SA 2015
+ * Author: Benjamin Gaignard <benjamin.gaignard@linaro.org> for Linaro.
+ * License terms:  GNU General Public License (GPL), version 2
+ */
+
+#include <linux/device.h>
+#include <linux/fs.h>
+#include <linux/ioctl.h>
+#include <linux/list_sort.h>
+#include <linux/miscdevice.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/smaf.h>
+#include <linux/smaf-allocator.h>
+#include <linux/smaf-secure.h>
+#include <linux/uaccess.h>
+
+struct smaf_handle {
+	struct dma_buf *dmabuf;
+	struct smaf_allocator *allocator;
+	struct dma_buf *db_alloc;
+	size_t length;
+	unsigned int flags;
+	int fd;
+	atomic_t is_secure;
+	void *secure_ctx;
+};
+
+/**
+ * struct smaf_device - smaf device node private data
+ * @misc_dev:	the misc device
+ * @head:	list of allocator
+ * @lock:	list and secure pointer mutex
+ * @secure:	pointer to secure functions helpers
+ */
+struct smaf_device {
+	struct miscdevice misc_dev;
+	struct list_head head;
+	/* list and secure pointer lock*/
+	struct mutex lock;
+	struct smaf_secure *secure;
+};
+
+static struct smaf_device smaf_dev;
+
+static bool have_secure_module(void)
+{
+	return !!smaf_dev.secure;
+}
+
+/**
+ * smaf_allow_cpu_access return true if CPU can access to memory
+ * if their is no secure module associated to SMAF assume that CPU can get
+ * access to the memory.
+ */
+static bool smaf_allow_cpu_access(struct smaf_handle *handle,
+				  unsigned long flags)
+{
+	bool ret = true;
+
+	if (!atomic_read(&handle->is_secure))
+		return true;
+
+	mutex_lock(&smaf_dev.lock);
+
+	if (!have_secure_module())
+		goto unlock;
+
+	ret = smaf_dev.secure->allow_cpu_access(handle->secure_ctx, flags);
+
+unlock:
+	mutex_unlock(&smaf_dev.lock);
+	return ret;
+}
+
+/**
+ * smaf_grant_access - return true if the specified device can get access
+ * to the memory area
+ *
+ * This function must be called with smaf_dev.lock set
+ */
+static bool smaf_grant_access(struct smaf_handle *handle, struct device *dev,
+			     dma_addr_t addr, size_t size,
+			     enum dma_data_direction dir)
+{
+	if (!atomic_read(&handle->is_secure))
+		return true;
+
+	if (!have_secure_module())
+		return false;
+
+	return smaf_dev.secure->grant_access(handle->secure_ctx,
+					     dev, addr, size, dir);
+}
+
+/**
+ * smaf_revoke_access
+ * This function must be called with smaf_dev.lock set
+ */
+static void smaf_revoke_access(struct smaf_handle *handle, struct device *dev,
+			       dma_addr_t addr, size_t size,
+			       enum dma_data_direction dir)
+{
+	if (!atomic_read(&handle->is_secure))
+		return;
+
+	if (!have_secure_module())
+		return;
+
+	smaf_dev.secure->revoke_access(handle->secure_ctx,
+				       dev, addr, size, dir);
+}
+
+static int smaf_secure_handle(struct smaf_handle *handle)
+{
+	if (atomic_read(&handle->is_secure))
+		return 0;
+
+	if (!have_secure_module())
+		return -EINVAL;
+
+	handle->secure_ctx = smaf_dev.secure->create_ctx();
+
+	if (!handle->secure_ctx)
+		return -EINVAL;
+
+	atomic_set(&handle->is_secure, 1);
+	return 0;
+}
+
+static int smaf_unsecure_handle(struct smaf_handle *handle)
+{
+	if (!atomic_read(&handle->is_secure))
+		return 0;
+
+	if (!have_secure_module())
+		return -EINVAL;
+
+	if (smaf_dev.secure->destroy_ctx(handle->secure_ctx))
+		return -EINVAL;
+
+	handle->secure_ctx = NULL;
+	atomic_set(&handle->is_secure, 0);
+	return 0;
+}
+
+int smaf_register_secure(struct smaf_secure *s)
+{
+	/* make sure that secure module have all required functions
+	 * to avoid test them each time later
+	 */
+	WARN_ON(!s || !s->create_ctx || !s->destroy_ctx
+		|| !s->grant_access || !s->revoke_access
+		|| !s->allow_cpu_access);
+
+	mutex_lock(&smaf_dev.lock);
+	smaf_dev.secure = s;
+	mutex_unlock(&smaf_dev.lock);
+
+	return 0;
+}
+EXPORT_SYMBOL(smaf_register_secure);
+
+void smaf_unregister_secure(struct smaf_secure *s)
+{
+	mutex_lock(&smaf_dev.lock);
+	if (smaf_dev.secure == s)
+		smaf_dev.secure = NULL;
+	mutex_unlock(&smaf_dev.lock);
+}
+EXPORT_SYMBOL(smaf_unregister_secure);
+
+static struct smaf_allocator *smaf_find_allocator(struct dma_buf *dmabuf)
+{
+	struct smaf_allocator *alloc;
+
+	list_for_each_entry(alloc, &smaf_dev.head, list_node) {
+		if (alloc->match(dmabuf))
+			return alloc;
+	}
+
+	return NULL;
+}
+
+static struct smaf_allocator *smaf_get_first_allocator(struct dma_buf *dmabuf)
+{
+	/* the first allocator of the list is the preferred allocator */
+	return list_first_entry(&smaf_dev.head, struct smaf_allocator,
+			list_node);
+}
+
+static int smaf_allocator_compare(void *priv,
+				  struct list_head *lh_a,
+				  struct list_head *lh_b)
+{
+	struct smaf_allocator *a = list_entry(lh_a,
+					      struct smaf_allocator, list_node);
+	struct smaf_allocator *b = list_entry(lh_b,
+					      struct smaf_allocator, list_node);
+	int diff;
+
+	diff = b->ranking - a->ranking;
+	if (diff)
+		return diff;
+
+	return strcmp(a->name, b->name);
+}
+
+int smaf_register_allocator(struct smaf_allocator *alloc)
+{
+	WARN_ON(!alloc || !alloc->match || !alloc->allocate || !alloc->name);
+
+	mutex_lock(&smaf_dev.lock);
+	list_add(&alloc->list_node, &smaf_dev.head);
+	list_sort(NULL, &smaf_dev.head, smaf_allocator_compare);
+	mutex_unlock(&smaf_dev.lock);
+
+	return 0;
+}
+EXPORT_SYMBOL(smaf_register_allocator);
+
+void smaf_unregister_allocator(struct smaf_allocator *alloc)
+{
+	mutex_lock(&smaf_dev.lock);
+	list_del(&alloc->list_node);
+	mutex_unlock(&smaf_dev.lock);
+}
+EXPORT_SYMBOL(smaf_unregister_allocator);
+
+static struct dma_buf_attachment *smaf_find_attachment(struct dma_buf *db_alloc,
+						       struct device *dev)
+{
+	struct dma_buf_attachment *attach_obj;
+
+	list_for_each_entry(attach_obj, &db_alloc->attachments, node) {
+		if (attach_obj->dev == dev)
+			return attach_obj;
+	}
+
+	return NULL;
+}
+
+static struct sg_table *smaf_map_dma_buf(struct dma_buf_attachment *attachment,
+					 enum dma_data_direction direction)
+{
+	struct dma_buf_attachment *db_attachment;
+	struct dma_buf *dmabuf = attachment->dmabuf;
+	struct smaf_handle *handle = dmabuf->priv;
+	struct sg_table *sgt;
+	unsigned count_done, count;
+	struct scatterlist *sg;
+
+
+	/* try to find an allocator */
+	if (!handle->allocator) {
+		struct smaf_allocator *alloc;
+
+		mutex_lock(&smaf_dev.lock);
+		alloc = smaf_find_allocator(dmabuf);
+		mutex_unlock(&smaf_dev.lock);
+
+		/* still no allocator ? */
+		if (!alloc)
+			return NULL;
+
+		handle->allocator = alloc;
+	}
+
+	if (!handle->db_alloc) {
+		struct dma_buf *db_alloc;
+
+		db_alloc = handle->allocator->allocate(dmabuf,
+						       handle->length,
+						       handle->flags);
+		if (!db_alloc)
+			return NULL;
+
+		handle->db_alloc = db_alloc;
+	}
+
+	db_attachment = smaf_find_attachment(handle->db_alloc, attachment->dev);
+	sgt = dma_buf_map_attachment(db_attachment, direction);
+
+	if (!sgt)
+		return NULL;
+
+	if (!atomic_read(&handle->is_secure))
+		return sgt;
+
+	mutex_lock(&smaf_dev.lock);
+
+	/* now secure the data */
+	for_each_sg(sgt->sgl, sg, sgt->nents, count_done) {
+		if (!smaf_grant_access(handle, db_attachment->dev,
+				       sg_phys(sg), sg->length, direction))
+			goto failed;
+	}
+
+	mutex_unlock(&smaf_dev.lock);
+	return sgt;
+
+failed:
+	for_each_sg(sgt->sgl, sg, count_done, count) {
+		smaf_revoke_access(handle, db_attachment->dev,
+				   sg_phys(sg), sg->length, direction);
+	}
+
+	mutex_unlock(&smaf_dev.lock);
+
+	sg_free_table(sgt);
+	kfree(sgt);
+	return NULL;
+}
+
+static void smaf_unmap_dma_buf(struct dma_buf_attachment *attachment,
+			       struct sg_table *sgt,
+			       enum dma_data_direction direction)
+{
+	struct dma_buf_attachment *db_attachment;
+	struct dma_buf *dmabuf = attachment->dmabuf;
+	struct smaf_handle *handle = dmabuf->priv;
+	struct scatterlist *sg;
+	unsigned count;
+
+	if (!handle->db_alloc)
+		return;
+
+	db_attachment = smaf_find_attachment(handle->db_alloc, attachment->dev);
+	if (!db_attachment)
+		return;
+
+	if (atomic_read(&handle->is_secure)) {
+		mutex_lock(&smaf_dev.lock);
+		for_each_sg(sgt->sgl, sg, sgt->nents, count) {
+			smaf_revoke_access(handle, db_attachment->dev,
+					   sg_phys(sg), sg->length, direction);
+		}
+		mutex_unlock(&smaf_dev.lock);
+	}
+
+	dma_buf_unmap_attachment(db_attachment, sgt, direction);
+}
+
+static int smaf_mmap(struct dma_buf *dmabuf, struct vm_area_struct *vma)
+{
+	struct smaf_handle *handle = dmabuf->priv;
+
+	if (!smaf_allow_cpu_access(handle, vma->vm_flags))
+		return -EINVAL;
+
+	/* if no allocator attached, get the first allocator */
+	if (!handle->allocator) {
+		struct smaf_allocator *alloc;
+
+		mutex_lock(&smaf_dev.lock);
+		alloc = smaf_get_first_allocator(dmabuf);
+		mutex_unlock(&smaf_dev.lock);
+
+		/* still no allocator ? */
+		if (!alloc)
+			return -EINVAL;
+
+		handle->allocator = alloc;
+	}
+
+	if (!handle->db_alloc) {
+		struct dma_buf *db_alloc;
+
+		db_alloc = handle->allocator->allocate(dmabuf,
+						       handle->length,
+						       handle->flags);
+		if (!db_alloc)
+			return -EINVAL;
+
+		handle->db_alloc = db_alloc;
+	}
+
+	return dma_buf_mmap(handle->db_alloc, vma, 0);
+}
+
+static void smaf_dma_buf_release(struct dma_buf *dmabuf)
+{
+	struct smaf_handle *handle = dmabuf->priv;
+
+	if (handle->db_alloc)
+		dma_buf_put(handle->db_alloc);
+
+	mutex_lock(&smaf_dev.lock);
+	smaf_unsecure_handle(handle);
+	mutex_unlock(&smaf_dev.lock);
+
+	kfree(handle);
+}
+
+static int smaf_dma_buf_begin_cpu_access(struct dma_buf *dmabuf, size_t start,
+					 size_t len,
+					 enum dma_data_direction direction)
+{
+	struct smaf_handle *handle = dmabuf->priv;
+
+	if (!smaf_allow_cpu_access(handle, direction))
+		return -EINVAL;
+
+	if (!handle->db_alloc)
+		return -EINVAL;
+
+	return dma_buf_begin_cpu_access(handle->db_alloc,
+					start, len, direction);
+}
+
+static void smaf_dma_buf_end_cpu_access(struct dma_buf *dmabuf, size_t start,
+					size_t len,
+					enum dma_data_direction direction)
+{
+	struct smaf_handle *handle = dmabuf->priv;
+
+	if (handle->db_alloc)
+		dma_buf_end_cpu_access(handle->db_alloc, start, len, direction);
+}
+
+static void *smaf_dma_buf_kmap_atomic(struct dma_buf *dmabuf,
+				      unsigned long offset)
+{
+	struct smaf_handle *handle = dmabuf->priv;
+
+	if (!handle->db_alloc)
+		return NULL;
+
+	if (!smaf_allow_cpu_access(handle, DMA_BIDIRECTIONAL))
+		return NULL;
+
+	return dma_buf_kmap_atomic(handle->db_alloc, offset);
+}
+
+static void smaf_dma_buf_kunmap_atomic(struct dma_buf *dmabuf,
+				       unsigned long offset, void *ptr)
+{
+	struct smaf_handle *handle = dmabuf->priv;
+
+	if (!handle->db_alloc)
+		return;
+
+	dma_buf_kunmap_atomic(handle->db_alloc, offset, ptr);
+}
+
+static void *smaf_dma_buf_kmap(struct dma_buf *dmabuf, unsigned long offset)
+{
+	struct smaf_handle *handle = dmabuf->priv;
+
+	if (!handle->db_alloc)
+		return NULL;
+
+	if (!smaf_allow_cpu_access(handle, DMA_BIDIRECTIONAL))
+		return NULL;
+
+	return dma_buf_kmap(handle->db_alloc, offset);
+}
+
+static void smaf_dma_buf_kunmap(struct dma_buf *dmabuf, unsigned long offset,
+				void *ptr)
+{
+	struct smaf_handle *handle = dmabuf->priv;
+
+	if (!handle->db_alloc)
+		return;
+
+	dma_buf_kunmap(handle->db_alloc, offset, ptr);
+}
+
+static void *smaf_dma_buf_vmap(struct dma_buf *dmabuf)
+{
+	struct smaf_handle *handle = dmabuf->priv;
+
+	if (!handle->db_alloc)
+		return NULL;
+
+	if (!smaf_allow_cpu_access(handle, DMA_BIDIRECTIONAL))
+		return NULL;
+
+	return dma_buf_vmap(handle->db_alloc);
+}
+
+static void smaf_dma_buf_vunmap(struct dma_buf *dmabuf, void *vaddr)
+{
+	struct smaf_handle *handle = dmabuf->priv;
+
+	if (!handle->db_alloc)
+		return;
+
+	dma_buf_vunmap(handle->db_alloc, vaddr);
+}
+
+static int smaf_attach(struct dma_buf *dmabuf, struct device *dev,
+		       struct dma_buf_attachment *attach)
+{
+	struct smaf_handle *handle = dmabuf->priv;
+	struct dma_buf_attachment *db_attach;
+
+	if (!handle->db_alloc)
+		return 0;
+
+	db_attach = dma_buf_attach(handle->db_alloc, dev);
+
+	return IS_ERR(db_attach);
+}
+
+static void smaf_detach(struct dma_buf *dmabuf,
+			struct dma_buf_attachment *attach)
+{
+	struct smaf_handle *handle = dmabuf->priv;
+	struct dma_buf_attachment *db_attachment;
+
+	if (!handle->db_alloc)
+		return;
+
+	db_attachment = smaf_find_attachment(handle->db_alloc, attach->dev);
+	dma_buf_detach(handle->db_alloc, db_attachment);
+}
+
+static struct dma_buf_ops smaf_dma_buf_ops = {
+	.attach = smaf_attach,
+	.detach = smaf_detach,
+	.map_dma_buf = smaf_map_dma_buf,
+	.unmap_dma_buf = smaf_unmap_dma_buf,
+	.mmap = smaf_mmap,
+	.release = smaf_dma_buf_release,
+	.begin_cpu_access = smaf_dma_buf_begin_cpu_access,
+	.end_cpu_access = smaf_dma_buf_end_cpu_access,
+	.kmap_atomic = smaf_dma_buf_kmap_atomic,
+	.kunmap_atomic = smaf_dma_buf_kunmap_atomic,
+	.kmap = smaf_dma_buf_kmap,
+	.kunmap = smaf_dma_buf_kunmap,
+	.vmap = smaf_dma_buf_vmap,
+	.vunmap = smaf_dma_buf_vunmap,
+};
+
+static bool is_smaf_dmabuf(struct dma_buf *dmabuf)
+{
+	return dmabuf->ops == &smaf_dma_buf_ops;
+}
+
+bool smaf_is_secure(struct dma_buf *dmabuf)
+{
+	struct smaf_handle *handle = dmabuf->priv;
+
+	if (!is_smaf_dmabuf(dmabuf))
+		return false;
+
+	return atomic_read(&handle->is_secure);
+}
+EXPORT_SYMBOL(smaf_is_secure);
+
+int smaf_set_secure(struct dma_buf *dmabuf, bool secure)
+{
+	struct smaf_handle *handle = dmabuf->priv;
+	int ret;
+
+	if (!is_smaf_dmabuf(dmabuf))
+		return -EINVAL;
+
+	mutex_lock(&smaf_dev.lock);
+	if (secure)
+		ret = smaf_secure_handle(handle);
+	else
+		ret = smaf_unsecure_handle(handle);
+	mutex_unlock(&smaf_dev.lock);
+
+	return ret;
+}
+EXPORT_SYMBOL(smaf_set_secure);
+
+int smaf_select_allocator_by_name(struct dma_buf *dmabuf, char *name)
+{
+	struct smaf_handle *handle = dmabuf->priv;
+	struct smaf_allocator *alloc;
+
+	if (!is_smaf_dmabuf(dmabuf))
+		return -EINVAL;
+
+	if (handle->allocator)
+		return -EINVAL;
+
+	mutex_lock(&smaf_dev.lock);
+
+	list_for_each_entry(alloc, &smaf_dev.head, list_node) {
+		if (!strncmp(alloc->name, name, ALLOCATOR_NAME_LENGTH)) {
+			handle->allocator = alloc;
+			handle->db_alloc = NULL;
+		}
+	}
+
+	mutex_unlock(&smaf_dev.lock);
+
+	if (!handle->allocator)
+		return -EINVAL;
+
+	return 0;
+}
+EXPORT_SYMBOL(smaf_select_allocator_by_name);
+
+struct smaf_handle *smaf_create_handle(size_t length, unsigned int flags)
+{
+	struct smaf_handle *handle;
+
+	DEFINE_DMA_BUF_EXPORT_INFO(info);
+
+	handle = kzalloc(sizeof(*handle), GFP_KERNEL);
+	if (!handle)
+		return ERR_PTR(-ENOMEM);
+
+	info.ops = &smaf_dma_buf_ops;
+	info.size = length;
+	info.flags = flags;
+	info.priv = handle;
+
+	handle->dmabuf = dma_buf_export(&info);
+	if (IS_ERR(handle->dmabuf)) {
+		kfree(handle);
+		return NULL;
+	}
+
+	handle->length = length;
+	handle->flags = flags;
+
+	return handle;
+}
+EXPORT_SYMBOL(smaf_create_handle);
+
+static long smaf_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
+{
+	switch (cmd) {
+	case SMAF_IOC_CREATE:
+	{
+		struct smaf_create_data data;
+		struct smaf_handle *handle;
+
+		if (copy_from_user(&data, (void __user *)arg, _IOC_SIZE(cmd)))
+			return -EFAULT;
+
+		handle = smaf_create_handle(data.length, data.flags);
+		if (!handle)
+			return -EINVAL;
+
+		if (data.name[0]) {
+			/* user force allocator selection */
+			if (smaf_select_allocator_by_name(handle->dmabuf,
+							  data.name)) {
+				dma_buf_put(handle->dmabuf);
+				return -EINVAL;
+			}
+		}
+
+		handle->fd = dma_buf_fd(handle->dmabuf, data.flags);
+		if (handle->fd < 0) {
+			dma_buf_put(handle->dmabuf);
+			return -EINVAL;
+		}
+
+		data.fd = handle->fd;
+		if (copy_to_user((void __user *)arg, &data, _IOC_SIZE(cmd))) {
+			dma_buf_put(handle->dmabuf);
+			return -EFAULT;
+		}
+		break;
+	}
+	case SMAF_IOC_GET_SECURE_FLAG:
+	{
+		struct smaf_secure_flag data;
+		struct dma_buf *dmabuf;
+
+		if (copy_from_user(&data, (void __user *)arg, _IOC_SIZE(cmd)))
+			return -EFAULT;
+
+		dmabuf = dma_buf_get(data.fd);
+		if (!dmabuf)
+			return -EINVAL;
+
+		data.secure = smaf_is_secure(dmabuf);
+		dma_buf_put(dmabuf);
+
+		if (copy_to_user((void __user *)arg, &data, _IOC_SIZE(cmd)))
+			return -EFAULT;
+		break;
+	}
+	case SMAF_IOC_SET_SECURE_FLAG:
+	{
+		struct smaf_secure_flag data;
+		struct dma_buf *dmabuf;
+		int ret;
+
+		if (!smaf_dev.secure)
+			return -EINVAL;
+
+		if (copy_from_user(&data, (void __user *)arg, _IOC_SIZE(cmd)))
+			return -EFAULT;
+
+		dmabuf = dma_buf_get(data.fd);
+		if (!dmabuf)
+			return -EINVAL;
+
+		ret = smaf_set_secure(dmabuf, data.secure);
+
+		dma_buf_put(dmabuf);
+
+		if (ret)
+			return -EINVAL;
+
+		break;
+	}
+	default:
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static const struct file_operations smaf_fops = {
+	.owner = THIS_MODULE,
+	.unlocked_ioctl = smaf_ioctl,
+};
+
+static int __init smaf_init(void)
+{
+	int ret = 0;
+
+	smaf_dev.misc_dev.minor = MISC_DYNAMIC_MINOR;
+	smaf_dev.misc_dev.name  = "smaf";
+	smaf_dev.misc_dev.fops  = &smaf_fops;
+
+	/* register misc device */
+	ret = misc_register(&smaf_dev.misc_dev);
+	if (ret < 0)
+		return ret;
+
+	mutex_init(&smaf_dev.lock);
+	INIT_LIST_HEAD(&smaf_dev.head);
+
+	return ret;
+}
+module_init(smaf_init);
+
+static void __exit smaf_deinit(void)
+{
+	misc_deregister(&smaf_dev.misc_dev);
+}
+module_exit(smaf_deinit);
+
+MODULE_DESCRIPTION("Secure Memory Allocation Framework");
+MODULE_LICENSE("GPL v2");
+MODULE_AUTHOR("Benjamin Gaignard <benjamin.gaignard@linaro.org>");
diff --git a/include/linux/smaf-allocator.h b/include/linux/smaf-allocator.h
new file mode 100644
index 0000000..f764ef4
--- /dev/null
+++ b/include/linux/smaf-allocator.h
@@ -0,0 +1,54 @@
+/*
+ * smaf-allocator.h
+ *
+ * Copyright (C) Linaro SA 2015
+ * Author: Benjamin Gaignard <benjamin.gaignard@linaro.org> for Linaro.
+ * License terms:  GNU General Public License (GPL), version 2
+ */
+
+#ifndef _SMAF_ALLOCATOR_H_
+#define _SMAF_ALLOCATOR_H_
+
+#include <linux/dma-buf.h>
+#include <linux/list.h>
+
+/**
+ * struct smaf_allocator - implement dma_buf_ops like functions
+ *
+ * @match: match function to check if allocator can accept the devices
+ *	   attached to dmabuf
+ * @allocate: allocate memory with the given length and flags
+ *	      return a dma_buf handle
+ * @name: allocator name
+ * @ranking: allocator ranking (bigger is better)
+ */
+struct smaf_allocator {
+	struct list_head list_node;
+	bool (*match)(struct dma_buf *dmabuf);
+	struct dma_buf *(*allocate)(struct dma_buf *dmabuf,
+				    size_t length, unsigned int flags);
+	const char *name;
+	int ranking;
+};
+
+/**
+ * smaf_register_allocator - register an allocator to be used by SMAF
+ * @alloc: smaf_allocator structure
+ */
+int smaf_register_allocator(struct smaf_allocator *alloc);
+
+/**
+ * smaf_unregister_allocator - unregister alloctor
+ * @alloc: smaf_allocator structure
+ */
+void smaf_unregister_allocator(struct smaf_allocator *alloc);
+
+/**
+ * smaf_select_allocator_by_name - select an allocator by it name
+ * return 0 if the allocator has been found and selected.
+ * @dmabuf: dma_buf buffer handler
+ * @name: name of the allocator to be selected
+ */
+int smaf_select_allocator_by_name(struct dma_buf *dmabuf, char *name);
+
+#endif
diff --git a/include/linux/smaf-secure.h b/include/linux/smaf-secure.h
new file mode 100644
index 0000000..4215334
--- /dev/null
+++ b/include/linux/smaf-secure.h
@@ -0,0 +1,75 @@
+/*
+ * smaf-secure.h
+ *
+ * Copyright (C) Linaro SA 2015
+ * Author: Benjamin Gaignard <benjamin.gaignard@linaro.org> for Linaro.
+ * License terms:  GNU General Public License (GPL), version 2
+ */
+
+#ifndef _SMAF_SECURE_H_
+#define _SMAF_SECURE_H_
+
+#include <linux/dma-buf.h>
+#include <linux/dma-mapping.h>
+
+/**
+ * struct smaf_secure
+ * @create_ctx:		create a context for one dmabuf.
+ * @destroy_ctx:	destroy context.
+ * @grant_access:	check and provide access to memory area for a specific
+ *			device. Return true if the request is valid.
+ * @revoke_access:	remove device access rights.
+ * @allow_cpu_access:	return true if CPU can access to memory
+ */
+struct smaf_secure {
+	void *(*create_ctx)(void);
+	int (*destroy_ctx)(void *ctx);
+	bool (*grant_access)(void *ctx,
+			     struct device *dev,
+			     size_t addr, size_t size,
+			     enum dma_data_direction direction);
+	void (*revoke_access)(void *ctx,
+			      struct device *dev,
+			      size_t addr, size_t size,
+			      enum dma_data_direction direction);
+	bool (*allow_cpu_access)(void *ctx, enum dma_data_direction direction);
+};
+
+/**
+ * smaf_register_secure - register secure module helper
+ * Secure module helper should be platform specific so only one can be
+ * registered.
+ *
+ * @sec: secure module to be registered
+ */
+int smaf_register_secure(struct smaf_secure *sec);
+
+/**
+ * smaf_unregister_secure - unregister secure module helper
+ */
+void smaf_unregister_secure(struct smaf_secure *sec);
+
+/**
+ * smaf_is_secure - test is a dma_buf handle has been secured by SMAF
+ * @dmabuf: dma_buf handle to be tested
+ */
+bool smaf_is_secure(struct dma_buf *dmabuf);
+
+/**
+ * smaf_set_secure - change dma_buf handle secure status
+ * @dmabuf: dma_buf handle to be change
+ * @secure: if true secure dma_buf handle
+ */
+int smaf_set_secure(struct dma_buf *dmabuf, bool secure);
+
+/**
+ * smaf_create_handle - create a smaf_handle with the give length and flags
+ * do not allocate memory but provide smaf_handle->dmabuf that can be
+ * shared between devices.
+ *
+ * @length: buffer size
+ * @flags: handle flags
+ */
+struct smaf_handle *smaf_create_handle(size_t length, unsigned int flags);
+
+#endif
diff --git a/include/uapi/linux/smaf.h b/include/uapi/linux/smaf.h
new file mode 100644
index 0000000..428168e
--- /dev/null
+++ b/include/uapi/linux/smaf.h
@@ -0,0 +1,52 @@
+/*
+ * smaf.h
+ *
+ * Copyright (C) Linaro SA 2015
+ * Author: Benjamin Gaignard <benjamin.gaignard@linaro.org> for Linaro.
+ * License terms:  GNU General Public License (GPL), version 2
+ */
+
+#ifndef _UAPI_SMAF_H_
+#define _UAPI_SMAF_H_
+
+#include <linux/ioctl.h>
+#include <linux/types.h>
+
+#define ALLOCATOR_NAME_LENGTH 64
+
+/**
+ * struct smaf_create_data - allocation parameters
+ * @length:	size of the allocation
+ * @flags:	flags passed to allocator
+ * @name:	name of the allocator to be selected, could be NULL
+ * @fd:		returned file descriptor
+ */
+struct smaf_create_data {
+	size_t length;
+	unsigned int flags;
+	char name[ALLOCATOR_NAME_LENGTH];
+	int fd;
+};
+
+/**
+ * struct smaf_secure_flag - set/get secure flag
+ * @fd:		file descriptor
+ * @secure:	secure flag value (set or get)
+ */
+struct smaf_secure_flag {
+	int fd;
+	int secure;
+};
+
+#define SMAF_IOC_MAGIC	'S'
+
+#define SMAF_IOC_CREATE		 _IOWR(SMAF_IOC_MAGIC, 0, \
+				       struct smaf_create_data)
+
+#define SMAF_IOC_GET_SECURE_FLAG _IOWR(SMAF_IOC_MAGIC, 1, \
+				       struct smaf_secure_flag)
+
+#define SMAF_IOC_SET_SECURE_FLAG _IOWR(SMAF_IOC_MAGIC, 2, \
+				       struct smaf_secure_flag)
+
+#endif
-- 
1.9.1

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[PATCH v5 2/3] SMAF: add CMA allocator

[Benjamin Gaignard]

SMAF CMA allocator implement helpers functions to allow SMAF
to allocate contiguous memory.

match() each if at least one of the attached devices have coherent_dma_mask
set to DMA_BIT_MASK(32).

For allocation it use dma_alloc_attrs() with DMA_ATTR_WRITE_COMBINE and not
dma_alloc_writecombine to be compatible with ARM 64bits architecture

Signed-off-by: Benjamin Gaignard <benjamin.gaignard@linaro.org>
---
 drivers/smaf/Kconfig    |   6 ++
 drivers/smaf/Makefile   |   1 +
 drivers/smaf/smaf-cma.c | 200 ++++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 207 insertions(+)
 create mode 100644 drivers/smaf/smaf-cma.c

diff --git a/drivers/smaf/Kconfig b/drivers/smaf/Kconfig
index d36651a..058ec4c 100644
--- a/drivers/smaf/Kconfig
+++ b/drivers/smaf/Kconfig
@@ -3,3 +3,9 @@ config SMAF
 	depends on DMA_SHARED_BUFFER
 	help
 	  Choose this option to enable Secure Memory Allocation Framework
+
+config SMAF_CMA
+	tristate "SMAF CMA allocator"
+	depends on SMAF && HAVE_DMA_ATTRS
+	help
+	  Choose this option to enable CMA allocation within SMAF
diff --git a/drivers/smaf/Makefile b/drivers/smaf/Makefile
index 40cd882..05bab01 100644
--- a/drivers/smaf/Makefile
+++ b/drivers/smaf/Makefile
@@ -1 +1,2 @@
 obj-$(CONFIG_SMAF) += smaf-core.o
+obj-$(CONFIG_SMAF_CMA) += smaf-cma.o
diff --git a/drivers/smaf/smaf-cma.c b/drivers/smaf/smaf-cma.c
new file mode 100644
index 0000000..012edd3
--- /dev/null
+++ b/drivers/smaf/smaf-cma.c
@@ -0,0 +1,200 @@
+/*
+ * smaf-cma.c
+ *
+ * Copyright (C) Linaro SA 2015
+ * Author: Benjamin Gaignard <benjamin.gaignard@linaro.org> for Linaro.
+ * License terms:  GNU General Public License (GPL), version 2
+ */
+
+#include <linux/dma-mapping.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/smaf-allocator.h>
+
+struct smaf_cma_buffer_info {
+	struct device *dev;
+	size_t size;
+	void *vaddr;
+	dma_addr_t paddr;
+};
+
+/**
+ * find_matching_device - iterate over the attached devices to find one
+ * with coherent_dma_mask correctly set to DMA_BIT_MASK(32).
+ * Matching device (if any) will be used to aim CMA area.
+ */
+static struct device *find_matching_device(struct dma_buf *dmabuf)
+{
+	struct dma_buf_attachment *attach_obj;
+
+	list_for_each_entry(attach_obj, &dmabuf->attachments, node) {
+		if (attach_obj->dev->coherent_dma_mask == DMA_BIT_MASK(32))
+			return attach_obj->dev;
+	}
+
+	return NULL;
+}
+
+/**
+ * smaf_cma_match - return true if at least one device has been found
+ */
+static bool smaf_cma_match(struct dma_buf *dmabuf)
+{
+	return !!find_matching_device(dmabuf);
+}
+
+static void smaf_cma_release(struct dma_buf *dmabuf)
+{
+	struct smaf_cma_buffer_info *info = dmabuf->priv;
+	DEFINE_DMA_ATTRS(attrs);
+
+	dma_set_attr(DMA_ATTR_WRITE_COMBINE, &attrs);
+
+	dma_free_attrs(info->dev, info->size, info->vaddr, info->paddr, &attrs);
+
+	kfree(info);
+}
+
+static struct sg_table *smaf_cma_map(struct dma_buf_attachment *attachment,
+				     enum dma_data_direction direction)
+{
+	struct smaf_cma_buffer_info *info = attachment->dmabuf->priv;
+	struct sg_table *sgt;
+	int ret;
+
+	sgt = kzalloc(sizeof(*sgt), GFP_KERNEL);
+	if (!sgt)
+		return NULL;
+
+	ret = dma_get_sgtable(info->dev, sgt, info->vaddr,
+			      info->paddr, info->size);
+	if (ret < 0)
+		goto out;
+
+	sg_dma_address(sgt->sgl) = info->paddr;
+	return sgt;
+
+out:
+	kfree(sgt);
+	return NULL;
+}
+
+static void smaf_cma_unmap(struct dma_buf_attachment *attachment,
+			   struct sg_table *sgt,
+			   enum dma_data_direction direction)
+{
+	/* do nothing */
+}
+
+static int smaf_cma_mmap(struct dma_buf *dmabuf, struct vm_area_struct *vma)
+{
+	struct smaf_cma_buffer_info *info = dmabuf->priv;
+	int ret;
+	DEFINE_DMA_ATTRS(attrs);
+
+	dma_set_attr(DMA_ATTR_WRITE_COMBINE, &attrs);
+
+	if (info->size < vma->vm_end - vma->vm_start)
+		return -EINVAL;
+
+	vma->vm_flags |= VM_IO | VM_PFNMAP | VM_DONTEXPAND | VM_DONTDUMP;
+	ret = dma_mmap_attrs(info->dev, vma, info->vaddr, info->paddr,
+			     info->size, &attrs);
+
+	return ret;
+}
+
+static void *smaf_cma_vmap(struct dma_buf *dmabuf)
+{
+	struct smaf_cma_buffer_info *info = dmabuf->priv;
+
+	return info->vaddr;
+}
+
+static void *smaf_kmap_atomic(struct dma_buf *dmabuf, unsigned long offset)
+{
+	struct smaf_cma_buffer_info *info = dmabuf->priv;
+
+	return (void *)info->vaddr + offset;
+}
+
+static struct dma_buf_ops smaf_cma_ops = {
+	.map_dma_buf = smaf_cma_map,
+	.unmap_dma_buf = smaf_cma_unmap,
+	.mmap = smaf_cma_mmap,
+	.release = smaf_cma_release,
+	.kmap_atomic = smaf_kmap_atomic,
+	.kmap = smaf_kmap_atomic,
+	.vmap = smaf_cma_vmap,
+};
+
+static struct dma_buf *smaf_cma_allocate(struct dma_buf *dmabuf,
+					 size_t length, unsigned int flags)
+{
+	struct dma_buf_attachment *attach_obj;
+	struct smaf_cma_buffer_info *info;
+	struct dma_buf *cma_dmabuf;
+	int ret;
+
+	DEFINE_DMA_BUF_EXPORT_INFO(export);
+	DEFINE_DMA_ATTRS(attrs);
+
+	dma_set_attr(DMA_ATTR_WRITE_COMBINE, &attrs);
+
+	info = kzalloc(sizeof(*info), GFP_KERNEL);
+	if (!info)
+		return NULL;
+
+	info->size = round_up(length, PAGE_SIZE);
+	info->dev = find_matching_device(dmabuf);
+
+	info->vaddr = dma_alloc_attrs(info->dev, info->size, &info->paddr,
+				      GFP_KERNEL | __GFP_NOWARN, &attrs);
+	if (!info->vaddr) {
+		ret = -ENOMEM;
+		goto error;
+	}
+
+	export.ops = &smaf_cma_ops;
+	export.size = info->size;
+	export.flags = flags;
+	export.priv = info;
+
+	cma_dmabuf = dma_buf_export(&export);
+	if (IS_ERR(cma_dmabuf))
+		goto error;
+
+	list_for_each_entry(attach_obj, &dmabuf->attachments, node) {
+		dma_buf_attach(cma_dmabuf, attach_obj->dev);
+	}
+
+	return cma_dmabuf;
+
+error:
+	kfree(info);
+	return NULL;
+}
+
+static struct smaf_allocator smaf_cma = {
+	.match = smaf_cma_match,
+	.allocate = smaf_cma_allocate,
+	.name = "smaf-cma",
+	.ranking = 0,
+};
+
+static int __init smaf_cma_init(void)
+{
+	INIT_LIST_HEAD(&smaf_cma.list_node);
+	return smaf_register_allocator(&smaf_cma);
+}
+module_init(smaf_cma_init);
+
+static void __exit smaf_cma_deinit(void)
+{
+	smaf_unregister_allocator(&smaf_cma);
+}
+module_exit(smaf_cma_deinit);
+
+MODULE_DESCRIPTION("SMAF CMA module");
+MODULE_LICENSE("GPL v2");
+MODULE_AUTHOR("Benjamin Gaignard <benjamin.gaignard@linaro.org>");
-- 
1.9.1

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[PATCH v5 3/3] SMAF: add fake secure module

[Benjamin Gaignard]

This module is allow testing secure calls of SMAF.

Signed-off-by: Benjamin Gaignard <benjamin.gaignard@linaro.org>
---
 drivers/smaf/Kconfig           |  6 +++
 drivers/smaf/Makefile          |  1 +
 drivers/smaf/smaf-fakesecure.c | 92 ++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 99 insertions(+)
 create mode 100644 drivers/smaf/smaf-fakesecure.c

diff --git a/drivers/smaf/Kconfig b/drivers/smaf/Kconfig
index 058ec4c..fd17005 100644
--- a/drivers/smaf/Kconfig
+++ b/drivers/smaf/Kconfig
@@ -9,3 +9,9 @@ config SMAF_CMA
 	depends on SMAF && HAVE_DMA_ATTRS
 	help
 	  Choose this option to enable CMA allocation within SMAF
+
+config SMAF_FAKE_SECURE
+	tristate "SMAF fake secure module"
+	depends on SMAF
+	help
+	  Choose this option to enable fake secure module for test purpose
diff --git a/drivers/smaf/Makefile b/drivers/smaf/Makefile
index 05bab01..00d5cd4 100644
--- a/drivers/smaf/Makefile
+++ b/drivers/smaf/Makefile
@@ -1,2 +1,3 @@
 obj-$(CONFIG_SMAF) += smaf-core.o
 obj-$(CONFIG_SMAF_CMA) += smaf-cma.o
+obj-$(CONFIG_SMAF_FAKE_SECURE) += smaf-fakesecure.o
diff --git a/drivers/smaf/smaf-fakesecure.c b/drivers/smaf/smaf-fakesecure.c
new file mode 100644
index 0000000..75e12dd
--- /dev/null
+++ b/drivers/smaf/smaf-fakesecure.c
@@ -0,0 +1,92 @@
+/*
+ * smaf-fakesecure.c
+ *
+ * Copyright (C) Linaro SA 2015
+ * Author: Benjamin Gaignard <benjamin.gaignard@linaro.org> for Linaro.
+ * License terms:  GNU General Public License (GPL), version 2
+ */
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/smaf-secure.h>
+
+#define MAGIC 0xDEADBEEF
+
+struct fake_private {
+	int magic;
+};
+
+static void *smaf_fakesecure_create(void)
+{
+	struct fake_private *priv;
+
+	priv = kzalloc(sizeof(*priv), GFP_KERNEL);
+	priv->magic = MAGIC;
+
+	return priv;
+}
+
+static int smaf_fakesecure_destroy(void *ctx)
+{
+	struct fake_private *priv = (struct fake_private *)ctx;
+
+	WARN_ON(!priv || (priv->magic != MAGIC));
+	kfree(priv);
+
+	return 0;
+}
+
+static bool smaf_fakesecure_grant_access(void *ctx,
+					 struct device *dev,
+					 size_t addr, size_t size,
+					 enum dma_data_direction direction)
+{
+	struct fake_private *priv = (struct fake_private *)ctx;
+
+	WARN_ON(!priv || (priv->magic != MAGIC));
+
+	return priv->magic == MAGIC;
+}
+
+static void smaf_fakesecure_revoke_access(void *ctx,
+					  struct device *dev,
+					  size_t addr, size_t size,
+					  enum dma_data_direction direction)
+{
+	struct fake_private *priv = (struct fake_private *)ctx;
+
+	WARN_ON(!priv || (priv->magic != MAGIC));
+}
+
+static bool smaf_fakesecure_allow_cpu_access(void *ctx,
+					     enum dma_data_direction direction)
+{
+	struct fake_private *priv = (struct fake_private *)ctx;
+
+	WARN_ON(!priv || (priv->magic != MAGIC));
+
+	return priv->magic == MAGIC;
+}
+
+static struct smaf_secure fake = {
+	.create_ctx = smaf_fakesecure_create,
+	.destroy_ctx = smaf_fakesecure_destroy,
+	.grant_access = smaf_fakesecure_grant_access,
+	.revoke_access = smaf_fakesecure_revoke_access,
+	.allow_cpu_access = smaf_fakesecure_allow_cpu_access,
+};
+
+static int __init smaf_fakesecure_init(void)
+{
+	return smaf_register_secure(&fake);
+}
+module_init(smaf_fakesecure_init);
+
+static void __exit smaf_fakesecure_deinit(void)
+{
+	smaf_unregister_secure(&fake);
+}
+module_exit(smaf_fakesecure_deinit);
+
+MODULE_DESCRIPTION("SMAF fake secure module for test purpose");
+MODULE_LICENSE("GPL v2");
+MODULE_AUTHOR("Benjamin Gaignard <benjamin.gaignard@linaro.org>");
-- 
1.9.1

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Re: [PATCH v5 1/3] create SMAF module

[James Morris]

On Wed, 21 Oct 2015, Benjamin Gaignard wrote:

> Secure Memory Allocation Framework goal is to be able
> to allocate memory that can be securing.
> There is so much ways to allocate and securing memory that SMAF
> doesn't do it by itself but need help of additional modules.
> To be sure to use the correct allocation method SMAF implement
> deferred allocation (i.e. allocate memory when only really needed)
> 
> Allocation modules (smaf-alloctor.h):
> SMAF could manage with multiple allocation modules at same time.
> To select the good one SMAF call match() to be sure that a module
> can allocate memory for a given list of devices. It is to the module
> to check if the devices are compatible or not with it allocation
> method.
> 
> Securing module (smaf-secure.h):
> The way of how securing memory it is done is platform specific.
> Secure module is responsible of grant/revoke memory access.
> 

This documentation is highly inadequate.

What does "allocate memory that can be securing" mean?


-- 
James Morris
<jmorris@namei.org>

Re: [PATCH v5 0/3] RFC: Secure Memory Allocation Framework

[James Morris]

On Wed, 21 Oct 2015, Benjamin Gaignard wrote:

> 
> The outcome of the previous RFC about how do secure data path was the need
> of a secure memory allocator (https://lkml.org/lkml/2015/5/5/551)
> 

Have you addressed all the questions raised by Alan here:

https://lkml.org/lkml/2015/5/8/629

Also, is there any application of this beyond DRM?


- James
-- 
James Morris
<jmorris@namei.org>

Re: [PATCH v5 1/3] create SMAF module

[Benjamin Gaignard]

2015-10-21 16:32 GMT+02:00 James Morris <jmorris@namei.org>:
> On Wed, 21 Oct 2015, Benjamin Gaignard wrote:
>
>> Secure Memory Allocation Framework goal is to be able
>> to allocate memory that can be securing.
>> There is so much ways to allocate and securing memory that SMAF
>> doesn't do it by itself but need help of additional modules.
>> To be sure to use the correct allocation method SMAF implement
>> deferred allocation (i.e. allocate memory when only really needed)
>>
>> Allocation modules (smaf-alloctor.h):
>> SMAF could manage with multiple allocation modules at same time.
>> To select the good one SMAF call match() to be sure that a module
>> can allocate memory for a given list of devices. It is to the module
>> to check if the devices are compatible or not with it allocation
>> method.
>>
>> Securing module (smaf-secure.h):
>> The way of how securing memory it is done is platform specific.
>> Secure module is responsible of grant/revoke memory access.
>>
>
> This documentation is highly inadequate.

If you give hints I will try to complete it and make it acceptable.

>
> What does "allocate memory that can be securing" mean?

Maybe I could re-phrase it like that:
"Secure Memory Allocation Framework goal is to be able to allocate
memory that the platform can secure."

I'm trying to be generic here because each could have it own method to
secure buffers.

>
>
> --
> James Morris
> <jmorris@namei.org>
>



-- 
Benjamin Gaignard

Graphic Working Group

Linaro.org │ Open source software for ARM SoCs

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Re: [PATCH v5 0/3] RFC: Secure Memory Allocation Framework

[Benjamin Gaignard]

2015-10-21 16:34 GMT+02:00 James Morris <jmorris@namei.org>:
> On Wed, 21 Oct 2015, Benjamin Gaignard wrote:
>
>>
>> The outcome of the previous RFC about how do secure data path was the need
>> of a secure memory allocator (https://lkml.org/lkml/2015/5/5/551)
>>
>
> Have you addressed all the questions raised by Alan here:
>
> https://lkml.org/lkml/2015/5/8/629

SMAF create /dev/smaf where all allocations could be done and is the
owner of the dmabuf.
Secure module is called to check permissions before that the CPU could
access to the memory.

I hope this cover what Alan expected but I can't speak form him.

>
> Also, is there any application of this beyond DRM?
>

If you don't use the secure part you can consider that SMAF is a
central allocator with helpers to select
the best allocator for your hardware devices.
While SMAF doesn't rely on DRM concepts (crypto, CENC, keys etc...) we
can use it outside this context but obviously it that been first
designed for DRM uses cases.

>
> - James
> --
> James Morris
> <jmorris@namei.org>
>



-- 
Benjamin Gaignard

Graphic Working Group

Linaro.org │ Open source software for ARM SoCs

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