Re: [PATCH v2 2/4] tee: Remove vmalloc page support

On Fri, Feb 03, 2023 at 08:06:33PM -0800, Ira Weiny wrote:

The kernel pages used by shm_get_kernel_pages() are allocated using GFP_KERNEL through the following call stack:

trusted_instantiate() trusted_payload_alloc() -> GFP_KERNEL

<trusted key op> tee_shm_register_kernel_buf() register_shm_helper() shm_get_kernel_pages()

Where <trusted key op> is one of:

trusted_key_unseal() trusted_key_get_random() trusted_key_seal()

Remove the vmalloc page support from shm_get_kernel_pages(). Replace with a warn on once.

Cc: Al Viro viro@zeniv.linux.org.uk Cc: "Fabio M. De Francesco" fmdefrancesco@gmail.com Cc: Christoph Hellwig hch@lst.de Cc: Linus Torvalds torvalds@linux-foundation.org Reviewed-by: Jens Wiklander jens.wiklander@linaro.org Signed-off-by: Ira Weiny ira.weiny@intel.com

---

drivers/tee/tee_shm.c | 36 ++++++++++++------------------------ 1 file changed, 12 insertions(+), 24 deletions(-)

Added to https://git.linaro.org/people/jens.wiklander/linux-tee.git/log/?h=get_kernel...

Thanks, Jens

diff --git a/drivers/tee/tee_shm.c b/drivers/tee/tee_shm.c index 27295bda3e0b..527a6eabc03e 100644 --- a/drivers/tee/tee_shm.c +++ b/drivers/tee/tee_shm.c @@ -24,37 +24,25 @@ static void shm_put_kernel_pages(struct page **pages, size_t page_count) static int shm_get_kernel_pages(unsigned long start, size_t page_count, struct page **pages) {

• struct kvec *kiov; 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;
  

• if (WARN_ON_ONCE(is_vmalloc_addr((void *)start)))

• return -EINVAL;
  

• for (n = 0; n < page_count; n++) {
  

• 	kiov[n].iov_base = (void *)(start + n * PAGE_SIZE);
  

• 	kiov[n].iov_len = PAGE_SIZE;
  

• }
  

• kiov = kcalloc(page_count, sizeof(*kiov), GFP_KERNEL);
• if (!kiov)

• return -ENOMEM;
  

• rc = get_kernel_pages(kiov, page_count, 0, pages);
  

• kfree(kiov);
  

• 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;

}

-- 2.39.1