OSCL-LXR linux-6.0.1/​drivers/​tee/​tee_shm.c	Source navigation Diff markup Identifier search General search
	Version: linux-6.0.1 spark-3.0.0 hadoop-3.2.0-src hadoop-3.3.0-src spark-2.4.7 linux-4.15.13 hadoop-2.7.4-src Revert   Change

 // SPDX-License-Identifier: GPL-2.0-only
 /*
  * Copyright (c) 2015-2017, 2019-2021 Linaro Limited
  */
 #include <linux/anon_inodes.h>
 #include <linux/device.h>
 #include <linux/idr.h>
 #include <linux/mm.h>
 #include <linux/sched.h>
 #include <linux/slab.h>
 #include <linux/tee_drv.h>
 #include <linux/uaccess.h>
 #include <linux/uio.h>
 #include "tee_private.h"
 
 static void shm_put_kernel_pages(struct page **pages, size_t page_count)
 {
     size_t n;
 
     for (n = 0; n < page_count; n++)
         put_page(pages[n]);
 }
 
 static int shm_get_kernel_pages(unsigned long start, size_t page_count,
                 struct page **pages)
 {
     size_t n;
     int rc;
 
     if (is_vmalloc_addr((void *)start)) {
         struct page *page;
 
         for (n = 0; n < page_count; n++) {
             page = vmalloc_to_page((void *)(start + PAGE_SIZE * n));
             if (!page)
                 return -ENOMEM;
 
             get_page(page);
             pages[n] = page;
         }
         rc = page_count;
     } else {
         struct kvec *kiov;
 
         kiov = kcalloc(page_count, sizeof(*kiov), GFP_KERNEL);
         if (!kiov)
             return -ENOMEM;
 
         for (n = 0; n < page_count; n++) {
             kiov[n].iov_base = (void *)(start + n * PAGE_SIZE);
             kiov[n].iov_len = PAGE_SIZE;
         }
 
         rc = get_kernel_pages(kiov, page_count, 0, pages);
         kfree(kiov);
     }
 
     return rc;
 }
 
 static void release_registered_pages(struct tee_shm *shm)
 {
     if (shm->pages) {
         if (shm->flags & TEE_SHM_USER_MAPPED)
             unpin_user_pages(shm->pages, shm->num_pages);
         else
             shm_put_kernel_pages(shm->pages, shm->num_pages);
 
         kfree(shm->pages);
     }
 }
 
 static void tee_shm_release(struct tee_device *teedev, struct tee_shm *shm)
 {
     if (shm->flags & TEE_SHM_POOL) {
         teedev->pool->ops->free(teedev->pool, shm);
     } else if (shm->flags & TEE_SHM_DYNAMIC) {
         int rc = teedev->desc->ops->shm_unregister(shm->ctx, shm);
 
         if (rc)
             dev_err(teedev->dev.parent,
                 "unregister shm %p failed: %d", shm, rc);
 
         release_registered_pages(shm);
     }
 
     teedev_ctx_put(shm->ctx);
 
     kfree(shm);
 
     tee_device_put(teedev);
 }
 
 static struct tee_shm *shm_alloc_helper(struct tee_context *ctx, size_t size,
                     size_t align, u32 flags, int id)
 {
     struct tee_device *teedev = ctx->teedev;
     struct tee_shm *shm;
     void *ret;
     int rc;
 
     if (!tee_device_get(teedev))
         return ERR_PTR(-EINVAL);
 
     if (!teedev->pool) {
         /* teedev has been detached from driver */
         ret = ERR_PTR(-EINVAL);
         goto err_dev_put;
     }
 
     shm = kzalloc(sizeof(*shm), GFP_KERNEL);
     if (!shm) {
         ret = ERR_PTR(-ENOMEM);
         goto err_dev_put;
     }
 
     refcount_set(&shm->refcount, 1);
     shm->flags = flags;
     shm->id = id;
 
     /*
      * We're assigning this as it is needed if the shm is to be
      * registered. If this function returns OK then the caller expected
      * to call teedev_ctx_get() or clear shm->ctx in case it's not
      * needed any longer.
      */
     shm->ctx = ctx;
 
     rc = teedev->pool->ops->alloc(teedev->pool, shm, size, align);
     if (rc) {
         ret = ERR_PTR(rc);
         goto err_kfree;
     }
 
     teedev_ctx_get(ctx);
     return shm;
 err_kfree:
     kfree(shm);
 err_dev_put:
     tee_device_put(teedev);
     return ret;
 }
 
 /**
  * tee_shm_alloc_user_buf() - Allocate shared memory for user space
  * @ctx:    Context that allocates the shared memory
  * @size:   Requested size of shared memory
  *
  * Memory allocated as user space shared memory is automatically freed when
  * the TEE file pointer is closed. The primary usage of this function is
  * when the TEE driver doesn't support registering ordinary user space
  * memory.
  *
  * @returns a pointer to 'struct tee_shm'
  */
 struct tee_shm *tee_shm_alloc_user_buf(struct tee_context *ctx, size_t size)
 {
     u32 flags = TEE_SHM_DYNAMIC | TEE_SHM_POOL;
     struct tee_device *teedev = ctx->teedev;
     struct tee_shm *shm;
     void *ret;
     int id;
 
     mutex_lock(&teedev->mutex);
     id = idr_alloc(&teedev->idr, NULL, 1, 0, GFP_KERNEL);
     mutex_unlock(&teedev->mutex);
     if (id < 0)
         return ERR_PTR(id);
 
     shm = shm_alloc_helper(ctx, size, PAGE_SIZE, flags, id);
     if (IS_ERR(shm)) {
         mutex_lock(&teedev->mutex);
         idr_remove(&teedev->idr, id);
         mutex_unlock(&teedev->mutex);
         return shm;
     }
 
     mutex_lock(&teedev->mutex);
     ret = idr_replace(&teedev->idr, shm, id);
     mutex_unlock(&teedev->mutex);
     if (IS_ERR(ret)) {
         tee_shm_free(shm);
         return ret;
     }
 
     return shm;
 }
 
 /**
  * tee_shm_alloc_kernel_buf() - Allocate shared memory for kernel buffer
  * @ctx:    Context that allocates the shared memory
  * @size:   Requested size of shared memory
  *
  * The returned memory registered in secure world and is suitable to be
  * passed as a memory buffer in parameter argument to
  * tee_client_invoke_func(). The memory allocated is later freed with a
  * call to tee_shm_free().
  *
  * @returns a pointer to 'struct tee_shm'
  */
 struct tee_shm *tee_shm_alloc_kernel_buf(struct tee_context *ctx, size_t size)
 {
     u32 flags = TEE_SHM_DYNAMIC | TEE_SHM_POOL;
 
     return shm_alloc_helper(ctx, size, PAGE_SIZE, flags, -1);
 }
 EXPORT_SYMBOL_GPL(tee_shm_alloc_kernel_buf);
 
 /**
  * tee_shm_alloc_priv_buf() - Allocate shared memory for a privately shared
  *                kernel buffer
  * @ctx:    Context that allocates the shared memory
  * @size:   Requested size of shared memory
  *
  * This function returns similar shared memory as
  * tee_shm_alloc_kernel_buf(), but with the difference that the memory
  * might not be registered in secure world in case the driver supports
  * passing memory not registered in advance.
  *
  * This function should normally only be used internally in the TEE
  * drivers.
  *
  * @returns a pointer to 'struct tee_shm'
  */
 struct tee_shm *tee_shm_alloc_priv_buf(struct tee_context *ctx, size_t size)
 {
     u32 flags = TEE_SHM_PRIV | TEE_SHM_POOL;
 
     return shm_alloc_helper(ctx, size, sizeof(long) * 2, flags, -1);
 }
 EXPORT_SYMBOL_GPL(tee_shm_alloc_priv_buf);
 
 static struct tee_shm *
 register_shm_helper(struct tee_context *ctx, unsigned long addr,
             size_t length, u32 flags, int id)
 {
     struct tee_device *teedev = ctx->teedev;
     struct tee_shm *shm;
     unsigned long start;
     size_t num_pages;
     void *ret;
     int rc;
 
     if (!tee_device_get(teedev))
         return ERR_PTR(-EINVAL);
 
     if (!teedev->desc->ops->shm_register ||
         !teedev->desc->ops->shm_unregister) {
         ret = ERR_PTR(-ENOTSUPP);
         goto err_dev_put;
     }
 
     teedev_ctx_get(ctx);
 
     shm = kzalloc(sizeof(*shm), GFP_KERNEL);
     if (!shm) {
         ret = ERR_PTR(-ENOMEM);
         goto err_ctx_put;
     }
 
     refcount_set(&shm->refcount, 1);
     shm->flags = flags;
     shm->ctx = ctx;
     shm->id = id;
     addr = untagged_addr(addr);
     start = rounddown(addr, PAGE_SIZE);
     shm->offset = addr - start;
     shm->size = length;
     num_pages = (roundup(addr + length, PAGE_SIZE) - start) / PAGE_SIZE;
     shm->pages = kcalloc(num_pages, sizeof(*shm->pages), GFP_KERNEL);
     if (!shm->pages) {
         ret = ERR_PTR(-ENOMEM);
         goto err_free_shm;
     }
 
     if (flags & TEE_SHM_USER_MAPPED)
         rc = pin_user_pages_fast(start, num_pages, FOLL_WRITE,
                      shm->pages);
     else
         rc = shm_get_kernel_pages(start, num_pages, shm->pages);
     if (rc > 0)
         shm->num_pages = rc;
     if (rc != num_pages) {
         if (rc >= 0)
             rc = -ENOMEM;
         ret = ERR_PTR(rc);
         goto err_put_shm_pages;
     }
 
     rc = teedev->desc->ops->shm_register(ctx, shm, shm->pages,
                          shm->num_pages, start);
     if (rc) {
         ret = ERR_PTR(rc);
         goto err_put_shm_pages;
     }
 
     return shm;
 err_put_shm_pages:
     if (flags & TEE_SHM_USER_MAPPED)
         unpin_user_pages(shm->pages, shm->num_pages);
     else
         shm_put_kernel_pages(shm->pages, shm->num_pages);
     kfree(shm->pages);
 err_free_shm:
     kfree(shm);
 err_ctx_put:
     teedev_ctx_put(ctx);
 err_dev_put:
     tee_device_put(teedev);
     return ret;
 }
 
 /**
  * tee_shm_register_user_buf() - Register a userspace shared memory buffer
  * @ctx:    Context that registers the shared memory
  * @addr:   The userspace address of the shared buffer
  * @length: Length of the shared buffer
  *
  * @returns a pointer to 'struct tee_shm'
  */
 struct tee_shm *tee_shm_register_user_buf(struct tee_context *ctx,
                       unsigned long addr, size_t length)
 {
     u32 flags = TEE_SHM_USER_MAPPED | TEE_SHM_DYNAMIC;
     struct tee_device *teedev = ctx->teedev;
     struct tee_shm *shm;
     void *ret;
     int id;
 
     if (!access_ok((void __user *)addr, length))
         return ERR_PTR(-EFAULT);
 
     mutex_lock(&teedev->mutex);
     id = idr_alloc(&teedev->idr, NULL, 1, 0, GFP_KERNEL);
     mutex_unlock(&teedev->mutex);
     if (id < 0)
         return ERR_PTR(id);
 
     shm = register_shm_helper(ctx, addr, length, flags, id);
     if (IS_ERR(shm)) {
         mutex_lock(&teedev->mutex);
         idr_remove(&teedev->idr, id);
         mutex_unlock(&teedev->mutex);
         return shm;
     }
 
     mutex_lock(&teedev->mutex);
     ret = idr_replace(&teedev->idr, shm, id);
     mutex_unlock(&teedev->mutex);
     if (IS_ERR(ret)) {
         tee_shm_free(shm);
         return ret;
     }
 
     return shm;
 }
 
 /**
  * tee_shm_register_kernel_buf() - Register kernel memory to be shared with
  *                 secure world
  * @ctx:    Context that registers the shared memory
  * @addr:   The buffer
  * @length: Length of the buffer
  *
  * @returns a pointer to 'struct tee_shm'
  */
 
 struct tee_shm *tee_shm_register_kernel_buf(struct tee_context *ctx,
                         void *addr, size_t length)
 {
     u32 flags = TEE_SHM_DYNAMIC;
 
     return register_shm_helper(ctx, (unsigned long)addr, length, flags, -1);
 }
 EXPORT_SYMBOL_GPL(tee_shm_register_kernel_buf);
 
 static int tee_shm_fop_release(struct inode *inode, struct file *filp)
 {
     tee_shm_put(filp->private_data);
     return 0;
 }
 
 static int tee_shm_fop_mmap(struct file *filp, struct vm_area_struct *vma)
 {
     struct tee_shm *shm = filp->private_data;
     size_t size = vma->vm_end - vma->vm_start;
 
     /* Refuse sharing shared memory provided by application */
     if (shm->flags & TEE_SHM_USER_MAPPED)
         return -EINVAL;
 
     /* check for overflowing the buffer's size */
     if (vma->vm_pgoff + vma_pages(vma) > shm->size >> PAGE_SHIFT)
         return -EINVAL;
 
     return remap_pfn_range(vma, vma->vm_start, shm->paddr >> PAGE_SHIFT,
                    size, vma->vm_page_prot);
 }
 
 static const struct file_operations tee_shm_fops = {
     .owner = THIS_MODULE,
     .release = tee_shm_fop_release,
     .mmap = tee_shm_fop_mmap,
 };
 
 /**
  * tee_shm_get_fd() - Increase reference count and return file descriptor
  * @shm:    Shared memory handle
  * @returns user space file descriptor to shared memory
  */
 int tee_shm_get_fd(struct tee_shm *shm)
 {
     int fd;
 
     if (shm->id < 0)
         return -EINVAL;
 
     /* matched by tee_shm_put() in tee_shm_op_release() */
     refcount_inc(&shm->refcount);
     fd = anon_inode_getfd("tee_shm", &tee_shm_fops, shm, O_RDWR);
     if (fd < 0)
         tee_shm_put(shm);
     return fd;
 }
 
 /**
  * tee_shm_free() - Free shared memory
  * @shm:    Handle to shared memory to free
  */
 void tee_shm_free(struct tee_shm *shm)
 {
     tee_shm_put(shm);
 }
 EXPORT_SYMBOL_GPL(tee_shm_free);
 
 /**
  * tee_shm_get_va() - Get virtual address of a shared memory plus an offset
  * @shm:    Shared memory handle
  * @offs:   Offset from start of this shared memory
  * @returns virtual address of the shared memory + offs if offs is within
  *  the bounds of this shared memory, else an ERR_PTR
  */
 void *tee_shm_get_va(struct tee_shm *shm, size_t offs)
 {
     if (!shm->kaddr)
         return ERR_PTR(-EINVAL);
     if (offs >= shm->size)
         return ERR_PTR(-EINVAL);
     return (char *)shm->kaddr + offs;
 }
 EXPORT_SYMBOL_GPL(tee_shm_get_va);
 
 /**
  * tee_shm_get_pa() - Get physical address of a shared memory plus an offset
  * @shm:    Shared memory handle
  * @offs:   Offset from start of this shared memory
  * @pa:     Physical address to return
  * @returns 0 if offs is within the bounds of this shared memory, else an
  *  error code.
  */
 int tee_shm_get_pa(struct tee_shm *shm, size_t offs, phys_addr_t *pa)
 {
     if (offs >= shm->size)
         return -EINVAL;
     if (pa)
         *pa = shm->paddr + offs;
     return 0;
 }
 EXPORT_SYMBOL_GPL(tee_shm_get_pa);
 
 /**
  * tee_shm_get_from_id() - Find shared memory object and increase reference
  * count
  * @ctx:    Context owning the shared memory
  * @id:     Id of shared memory object
  * @returns a pointer to 'struct tee_shm' on success or an ERR_PTR on failure
  */
 struct tee_shm *tee_shm_get_from_id(struct tee_context *ctx, int id)
 {
     struct tee_device *teedev;
     struct tee_shm *shm;
 
     if (!ctx)
         return ERR_PTR(-EINVAL);
 
     teedev = ctx->teedev;
     mutex_lock(&teedev->mutex);
     shm = idr_find(&teedev->idr, id);
     /*
      * If the tee_shm was found in the IDR it must have a refcount
      * larger than 0 due to the guarantee in tee_shm_put() below. So
      * it's safe to use refcount_inc().
      */
     if (!shm || shm->ctx != ctx)
         shm = ERR_PTR(-EINVAL);
     else
         refcount_inc(&shm->refcount);
     mutex_unlock(&teedev->mutex);
     return shm;
 }
 EXPORT_SYMBOL_GPL(tee_shm_get_from_id);
 
 /**
  * tee_shm_put() - Decrease reference count on a shared memory handle
  * @shm:    Shared memory handle
  */
 void tee_shm_put(struct tee_shm *shm)
 {
     struct tee_device *teedev = shm->ctx->teedev;
     bool do_release = false;
 
     mutex_lock(&teedev->mutex);
     if (refcount_dec_and_test(&shm->refcount)) {
         /*
          * refcount has reached 0, we must now remove it from the
          * IDR before releasing the mutex. This will guarantee that
          * the refcount_inc() in tee_shm_get_from_id() never starts
          * from 0.
          */
         if (shm->id >= 0)
             idr_remove(&teedev->idr, shm->id);
         do_release = true;
     }
     mutex_unlock(&teedev->mutex);
 
     if (do_release)
         tee_shm_release(teedev, shm);
 }
 EXPORT_SYMBOL_GPL(tee_shm_put);

This page was automatically generated by the 2.1.0 LXR engine. The LXR team