Re: [Tee-dev] [PATCH v4 1/2] tee: enable support to register kernel memory

Hi Jens,

On Wed, 25 Mar 2020 at 14:00, Jens Wiklander jens.wiklander@linaro.org wrote:

Hi Sumit,

On Mon, Mar 23, 2020 at 1:19 PM Sumit Garg sumit.garg@linaro.org wrote:

...

Enable support to register kernel memory reference with TEE. This change will allow TEE bus drivers to register memory references.

Signed-off-by: Sumit Garg sumit.garg@linaro.org

drivers/tee/tee_shm.c | 26 ++++++++++++++++++++++++-- include/linux/tee_drv.h | 1 + 2 files changed, 25 insertions(+), 2 deletions(-)

diff --git a/drivers/tee/tee_shm.c b/drivers/tee/tee_shm.c index 937ac5a..b88274c 100644 --- a/drivers/tee/tee_shm.c +++ b/drivers/tee/tee_shm.c @@ -9,6 +9,7 @@ #include <linux/sched.h> #include <linux/slab.h> #include <linux/tee_drv.h> +#include <linux/uio.h> #include "tee_private.h"

static void tee_shm_release(struct tee_shm *shm) @@ -218,13 +219,14 @@ struct tee_shm *tee_shm_register(struct tee_context *ctx, unsigned long addr, { struct tee_device *teedev = ctx->teedev; const u32 req_flags = TEE_SHM_DMA_BUF | TEE_SHM_USER_MAPPED;

•   const u32 req_ker_flags = TEE_SHM_DMA_BUF | TEE_SHM_KERNEL_MAPPED;
  

I'd prefer naming these two "req_user_flags" and "req_kernel_flags".

Okay, will update these in the next version.

-Sumit

Thanks, Jens

...

    struct tee_shm *shm;
    void *ret;
    int rc;
    int num_pages;
    unsigned long start;

•   if (flags != req_flags)
  

•   if (flags != req_flags && flags != req_ker_flags)
            return ERR_PTR(-ENOTSUPP);
  
    if (!tee_device_get(teedev))
  

@@ -259,7 +261,27 @@ struct tee_shm *tee_shm_register(struct tee_context *ctx, unsigned long addr, goto err; }

•   rc = get_user_pages_fast(start, num_pages, FOLL_WRITE, shm->pages);
  

•   if (flags & TEE_SHM_USER_MAPPED) {
  

•           rc = get_user_pages_fast(start, num_pages, FOLL_WRITE,
  

•                                    shm->pages);
  

•   } else {
  

•           struct kvec *kiov;
  

•           int i;
  

•           kiov = kcalloc(num_pages, sizeof(*kiov), GFP_KERNEL);
  

•           if (!kiov) {
  

•                   ret = ERR_PTR(-ENOMEM);
  

•                   goto err;
  

•           }
  

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

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

•                   kiov[i].iov_len = PAGE_SIZE;
  

•           }
  

•           rc = get_kernel_pages(kiov, num_pages, 0, shm->pages);
  

•           kfree(kiov);
  

•   }
    if (rc > 0)
            shm->num_pages = rc;
    if (rc != num_pages) {
  

diff --git a/include/linux/tee_drv.h b/include/linux/tee_drv.h index 7a03f68..dedf8fa 100644 --- a/include/linux/tee_drv.h +++ b/include/linux/tee_drv.h @@ -26,6 +26,7 @@ #define TEE_SHM_REGISTER BIT(3) /* Memory registered in secure world */ #define TEE_SHM_USER_MAPPED BIT(4) /* Memory mapped in user space */ #define TEE_SHM_POOL BIT(5) /* Memory allocated from pool */ +#define TEE_SHM_KERNEL_MAPPED BIT(6) /* Memory mapped in kernel space */

struct device; struct tee_device; -- 2.7.4