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

Hi Ira,

On Sun, Oct 2, 2022 at 2:23 AM ira.weiny@intel.com wrote:

From: Ira Weiny ira.weiny@intel.com

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: Jens Wiklander jens.wiklander@linaro.org 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 Signed-off-by: Ira Weiny ira.weiny@intel.com

---

Jens I went with the suggestion from Linus and Christoph and rejected vmalloc addresses. I did not hear back from you regarding Linus' question if the vmalloc page support was required by an up coming patch set or not. So I assumed it was something out of tree.

Yes, that's correctly assumed, sorry for not confirming that earlier.

Reviewed-by: Jens Wiklander jens.wiklander@linaro.org

Thanks, Jens

---

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

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;
  

}

-- 2.37.2