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tee: Use iov_iter to better support shared buffer registration

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Currently it's not possible to register kernel buffers with TEE
which are allocated via vmalloc.

Use iov_iter and associated helper functions to manage the page
registration for all type of memories.

Suggested-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Arnaud Pouliquen <arnaud.pouliquen@foss.st.com>
Reviewed-by: Sumit Garg <sumit.garg@linaro.org>
Signed-off-by: Jens Wiklander <jens.wiklander@linaro.org>
This commit is contained in:
Arnaud Pouliquen
2023-12-05 17:23:30 +01:00
committed by Jens Wiklander
parent b85ea95d08
commit 7bdee41575
1 changed files with 42 additions and 36 deletions
Download Patch File Download Diff File Expand all files Collapse all files

78
drivers/tee/tee_shm.c
View File

@@ -22,23 +22,12 @@ static void shm_put_kernel_pages(struct page **pages, size_t page_count)
put_page(pages[n]); put_page(pages[n]);
} }
static int shm_get_kernel_pages(unsigned long start, size_t page_count, static void shm_get_kernel_pages(struct page **pages, size_t page_count)
struct page **pages)
{ {
struct page *page;
size_t n; size_t n;
if (WARN_ON_ONCE(is_vmalloc_addr((void *)start) || for (n = 0; n < page_count; n++)
is_kmap_addr((void *)start)))
return -EINVAL;
page = virt_to_page((void *)start);
for (n = 0; n < page_count; n++) {
pages[n] = page + n;
get_page(pages[n]); get_page(pages[n]);
}
return page_count;
} }
static void release_registered_pages(struct tee_shm *shm) static void release_registered_pages(struct tee_shm *shm)
@@ -214,13 +203,14 @@ struct tee_shm *tee_shm_alloc_priv_buf(struct tee_context *ctx, size_t size)
EXPORT_SYMBOL_GPL(tee_shm_alloc_priv_buf); EXPORT_SYMBOL_GPL(tee_shm_alloc_priv_buf);
static struct tee_shm * static struct tee_shm *
register_shm_helper(struct tee_context *ctx, unsigned long addr, register_shm_helper(struct tee_context *ctx, struct iov_iter *iter, u32 flags,
size_t length, u32 flags, int id) int id)
{ {
struct tee_device *teedev = ctx->teedev; struct tee_device *teedev = ctx->teedev;
struct tee_shm *shm; struct tee_shm *shm;
unsigned long start; unsigned long start, addr;
size_t num_pages; size_t num_pages, off;
ssize_t len;
void *ret; void *ret;
int rc; int rc;
@@ -245,31 +235,38 @@ register_shm_helper(struct tee_context *ctx, unsigned long addr,
shm->flags = flags; shm->flags = flags;
shm->ctx = ctx; shm->ctx = ctx;
shm->id = id; shm->id = id;
addr = untagged_addr(addr); addr = untagged_addr((unsigned long)iter_iov_addr(iter));
start = rounddown(addr, PAGE_SIZE); start = rounddown(addr, PAGE_SIZE);
shm->offset = addr - start; num_pages = iov_iter_npages(iter, INT_MAX);
shm->size = length; if (!num_pages) {
num_pages = (roundup(addr + length, PAGE_SIZE) - start) / PAGE_SIZE; ret = ERR_PTR(-ENOMEM);
goto err_ctx_put;
}
shm->pages = kcalloc(num_pages, sizeof(*shm->pages), GFP_KERNEL); shm->pages = kcalloc(num_pages, sizeof(*shm->pages), GFP_KERNEL);
if (!shm->pages) { if (!shm->pages) {
ret = ERR_PTR(-ENOMEM); ret = ERR_PTR(-ENOMEM);
goto err_free_shm; goto err_free_shm;
} }
if (flags & TEE_SHM_USER_MAPPED) len = iov_iter_extract_pages(iter, &shm->pages, LONG_MAX, num_pages, 0,
rc = pin_user_pages_fast(start, num_pages, FOLL_WRITE, &off);
shm->pages); if (unlikely(len <= 0)) {
else ret = len ? ERR_PTR(len) : ERR_PTR(-ENOMEM);
rc = shm_get_kernel_pages(start, num_pages, shm->pages); goto err_free_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;
} }
/*
* iov_iter_extract_kvec_pages does not get reference on the pages,
* get a reference on them.
*/
if (iov_iter_is_kvec(iter))
shm_get_kernel_pages(shm->pages, num_pages);
shm->offset = off;
shm->size = len;
shm->num_pages = num_pages;
rc = teedev->desc->ops->shm_register(ctx, shm, shm->pages, rc = teedev->desc->ops->shm_register(ctx, shm, shm->pages,
shm->num_pages, start); shm->num_pages, start);
if (rc) { if (rc) {
@@ -279,10 +276,11 @@ register_shm_helper(struct tee_context *ctx, unsigned long addr,
return shm; return shm;
err_put_shm_pages: err_put_shm_pages:
if (flags & TEE_SHM_USER_MAPPED) if (!iov_iter_is_kvec(iter))
unpin_user_pages(shm->pages, shm->num_pages); unpin_user_pages(shm->pages, shm->num_pages);
else else
shm_put_kernel_pages(shm->pages, shm->num_pages); shm_put_kernel_pages(shm->pages, shm->num_pages);
err_free_shm_pages:
kfree(shm->pages); kfree(shm->pages);
err_free_shm: err_free_shm:
kfree(shm); kfree(shm);
@@ -307,6 +305,7 @@ struct tee_shm *tee_shm_register_user_buf(struct tee_context *ctx,
u32 flags = TEE_SHM_USER_MAPPED | TEE_SHM_DYNAMIC; u32 flags = TEE_SHM_USER_MAPPED | TEE_SHM_DYNAMIC;
struct tee_device *teedev = ctx->teedev; struct tee_device *teedev = ctx->teedev;
struct tee_shm *shm; struct tee_shm *shm;
struct iov_iter iter;
void *ret; void *ret;
int id; int id;
@@ -319,7 +318,8 @@ struct tee_shm *tee_shm_register_user_buf(struct tee_context *ctx,
if (id < 0) if (id < 0)
return ERR_PTR(id); return ERR_PTR(id);
shm = register_shm_helper(ctx, addr, length, flags, id); iov_iter_ubuf(&iter, ITER_DEST, (void __user *)addr, length);
shm = register_shm_helper(ctx, &iter, flags, id);
if (IS_ERR(shm)) { if (IS_ERR(shm)) {
mutex_lock(&teedev->mutex); mutex_lock(&teedev->mutex);
idr_remove(&teedev->idr, id); idr_remove(&teedev->idr, id);
@@ -352,8 +352,14 @@ struct tee_shm *tee_shm_register_kernel_buf(struct tee_context *ctx,
void *addr, size_t length) void *addr, size_t length)
{ {
u32 flags = TEE_SHM_DYNAMIC; u32 flags = TEE_SHM_DYNAMIC;
struct kvec kvec;
struct iov_iter iter;
return register_shm_helper(ctx, (unsigned long)addr, length, flags, -1); kvec.iov_base = addr;
kvec.iov_len = length;
iov_iter_kvec(&iter, ITER_DEST, &kvec, 1, length);
return register_shm_helper(ctx, &iter, flags, -1);
} }
EXPORT_SYMBOL_GPL(tee_shm_register_kernel_buf); EXPORT_SYMBOL_GPL(tee_shm_register_kernel_buf);