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 (2): create SMAF module SMAF: add CMA allocator
drivers/Kconfig | 2 + drivers/Makefile | 1 + drivers/smaf/Kconfig | 11 + drivers/smaf/Makefile | 2 + drivers/smaf/smaf-cma.c | 200 +++++++++++ drivers/smaf/smaf-core.c | 735 +++++++++++++++++++++++++++++++++++++++++ include/linux/smaf-allocator.h | 54 +++ include/linux/smaf-secure.h | 62 ++++ include/uapi/linux/smaf.h | 52 +++ 9 files changed, 1119 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 include/linux/smaf-allocator.h create mode 100644 include/linux/smaf-secure.h create mode 100644 include/uapi/linux/smaf.h
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 | 735 +++++++++++++++++++++++++++++++++++++++++ include/linux/smaf-allocator.h | 54 +++ include/linux/smaf-secure.h | 62 ++++ include/uapi/linux/smaf.h | 52 +++ 8 files changed, 912 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 c0cc96b..2421fcb 100644 --- a/drivers/Kconfig +++ b/drivers/Kconfig @@ -182,4 +182,6 @@ source "drivers/thunderbolt/Kconfig"
source "drivers/android/Kconfig"
+source "drivers/smaf/Kconfig" + endmenu diff --git a/drivers/Makefile b/drivers/Makefile index 46d2554..0cca66e 100644 --- a/drivers/Makefile +++ b/drivers/Makefile @@ -165,3 +165,4 @@ obj-$(CONFIG_RAS) += ras/ obj-$(CONFIG_THUNDERBOLT) += thunderbolt/ obj-$(CONFIG_CORESIGHT) += hwtracing/coresight/ obj-$(CONFIG_ANDROID) += android/ +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..90a7a97 --- /dev/null +++ b/drivers/smaf/smaf-core.c @@ -0,0 +1,735 @@ +/* + * 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/dma-buf.h> +#include <linux/dma-mapping.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; + bool 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; + +/** + * 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) +{ + if (!handle->is_secure) + return true; + + if (!smaf_dev.secure) + return true; + + if (!smaf_dev.secure->allow_cpu_access) + return true; + + return smaf_dev.secure->allow_cpu_access(handle->secure_ctx, flags); +} + +static int smaf_grant_access(struct smaf_handle *handle, struct device *dev, + dma_addr_t addr, size_t size, + enum dma_data_direction dir) +{ + if (!handle->is_secure) + return 0; + + if (!smaf_dev.secure) + return -EINVAL; + + if (!smaf_dev.secure->grant_access) + return -EINVAL; + + return smaf_dev.secure->grant_access(handle->secure_ctx, + dev, addr, size, dir); +} + +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 (!handle->is_secure) + return; + + if (!smaf_dev.secure) + return; + + if (!smaf_dev.secure->revoke_access) + return; + + smaf_dev.secure->revoke_access(handle->secure_ctx, + dev, addr, size, dir); +} + +static int smaf_secure_handle(struct smaf_handle *handle) +{ + if (handle->is_secure) + return 0; + + if (!smaf_dev.secure) + return -EINVAL; + + if (!smaf_dev.secure->create_context) + return -EINVAL; + + handle->secure_ctx = smaf_dev.secure->create_context(); + + if (!handle->secure_ctx) + return -EINVAL; + + handle->is_secure = true; + return 0; +} + +static int smaf_unsecure_handle(struct smaf_handle *handle) +{ + if (!handle->is_secure) + return 0; + + if (!smaf_dev.secure) + return -EINVAL; + + if (!smaf_dev.secure->destroy_context) + return -EINVAL; + + if (smaf_dev.secure->destroy_context(handle->secure_ctx)) + return -EINVAL; + + handle->secure_ctx = NULL; + handle->is_secure = false; + return 0; +} + +int smaf_register_secure(struct smaf_secure *s) +{ + if (smaf_dev.secure || !s) + return -EINVAL; + + 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) +{ + BUG_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; + + if (handle->is_secure && !smaf_dev.secure) + return NULL; + + /* 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 (!handle->is_secure) + return sgt; + + /* 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; + } + + 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); + } + + 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 (handle->is_secure) { + for_each_sg(sgt->sgl, sg, sgt->nents, count) { + smaf_revoke_access(handle, db_attachment->dev, + sg_phys(sg), sg->length, direction); + } + } + + 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); + + smaf_unsecure_handle(handle); + + 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 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); + +static 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; +} + +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..5bbf56c --- /dev/null +++ b/include/linux/smaf-secure.h @@ -0,0 +1,62 @@ +/* + * 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_ + +/** + * struct smaf_secure + * @create_context: create a secure context for one dmabuf. + * @destroy_context: destroy secure context. + * @grant_access: check and provide access to memroy area for a specific + * device. + * @revoke_access: remove device access rights. + * @allow_cpu_access: return true if CPU can access to memory + */ +struct smaf_secure { + void *(*create_context)(void); + int (*destroy_context)(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); + +#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
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..ab38717 --- /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->paddr + 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; +} + +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");
Hi all,
This thread doesn't get any feedback...
What would be great is to know if this framework proposal fir with your platform needs.
Maybe I haven't copy the good mailing lists so if you think there is better ones do not hesitate to forward.
Regards, Benjamin
2015-07-10 14:28 GMT+02:00 Benjamin Gaignard benjamin.gaignard@linaro.org:
Hi Benjamin,
It looks like this framework only allows user space client to talk with trust application, it there a plan to provide kernel side APIs for kernel space client?
Please correct me if my understanding is wrong.
Thanks
Xiaoquan
-----Original Message----- From: Linaro-mm-sig [mailto:linaro-mm-sig-bounces@lists.linaro.org] On Behalf Of Benjamin Gaignard Sent: Monday, July 27, 2015 6:12 PM To: linux-media@vger.kernel.org; Linux Kernel Mailing List; dri-devel@lists.freedesktop.org; Hans Verkuil; Laurent Pinchart; Daniel Vetter; Rob Clark; Thierry Reding; Sumit Semwal; Tom Cooksey; Daniel Stone Cc: Linaro MM SIG Mailman List Subject: Re: [Linaro-mm-sig] [PATCH v3 0/2] RFC: Secure Memory Allocation Framework
Hi all,
This thread doesn't get any feedback...
What would be great is to know if this framework proposal fir with your platform needs.
Maybe I haven't copy the good mailing lists so if you think there is better ones do not hesitate to forward.
Regards, Benjamin
2015-07-10 14:28 GMT+02:00 Benjamin Gaignard benjamin.gaignard@linaro.org:
There is an API to do the same operation on kernel side than on userland. You can get an dmabuf handle, select the allocator if required, and secure it on kernel side.
Your question makes me realize that I have forget to add an EXPORT_SYMBOL for smaf_create_handle function, I will fix that.
Benjamin
2015-07-28 4:22 GMT+02:00 Xiaoquan Li xiaoquan.li@vivantecorp.com:
linaro-mm-sig@lists.linaro.org
-
Benjamin Gaignard -
Xiaoquan Li