Re: [PATCH] tee: make tee_shm_register_kernel_buf vmalloc supported

On Sun, Feb 13, 2022 at 5:21 PM Phil Chang phil.chang@mediatek.com wrote:

In some low-memory devices, it's hard to aquire large-orders pages, this patch allowed user using scatter pages to register shm.

Signed-off-by: Phil Chang phil.chang@mediatek.com

drivers/tee/optee/call.c | 2 +- drivers/tee/tee_shm.c | 40 ++++++++++++++++++++++++++++------------ 2 files changed, 29 insertions(+), 13 deletions(-)

diff --git a/drivers/tee/optee/call.c b/drivers/tee/optee/call.c index bd49ec934060..2082e632adff 100644 --- a/drivers/tee/optee/call.c +++ b/drivers/tee/optee/call.c @@ -362,7 +362,7 @@ int optee_check_mem_type(unsigned long start, size_t num_pages) * Allow kernel address to register with OP-TEE as kernel * pages are configured as normal memory only. */

•   if (virt_addr_valid(start))
  

•   if (virt_addr_valid(start) || is_vmalloc_addr((void *)start))
            return 0;
  
    mmap_read_lock(mm);
  

diff --git a/drivers/tee/tee_shm.c b/drivers/tee/tee_shm.c index f31e29e8f1ca..861403588485 100644 --- a/drivers/tee/tee_shm.c +++ b/drivers/tee/tee_shm.c @@ -23,22 +23,38 @@ 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;
  
  

•   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;
  

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

•           struct page *page;
  

•           int i;
  

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

page_count is of an unsigned type and i is of a signed type, this is bound to cause a warning. Please move the "n" variable below to the top of this function and use that as an index variable here too.

•                   page = vmalloc_to_page((void *)(start + PAGE_SIZE * i));
  

•                   if (!page)
  

•                           return -ENOMEM;
  

•                   get_page(page);
  

•                   pages[i] = page;
  

•           }
  

•           rc = page_count;
  

•   } else {
  

•           struct kvec *kiov;
  

•           size_t n;
  

•           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);
    }
  
  

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

•   kfree(kiov);
  

•   return rc;
  

}

-- 2.25.1

This patch makes sense. Please fix the comment above and post a v3 (with a changelog this time).

Cheers, Jens