Earlier this patch-set was part of TEE Trusted keys patch-set [1]. But
since these are completely independent enhancements for TEE kernel
client interface which can be merged separately while TEE Trusted keys
discussions are ongoing.
Patch #1 enables support for registered kernel shared memory with TEE.
Patch #2 enables support for private kernel login method required for
cases like trusted keys where we don't wan't user-space to directly
access TEE service.
[1] https://lkml.org/lkml/2019/10/31/430
Changes in v6:
- Reserve only half of GP implementation defined range for kernel space.
Changes in v5:
- Misc. renaming of variables.
Sumit Garg (2):
tee: enable support to register kernel memory
tee: add private login method for kernel clients
drivers/tee/tee_core.c | 7 +++++++
drivers/tee/tee_shm.c | 28 +++++++++++++++++++++++++---
include/linux/tee_drv.h | 1 +
include/uapi/linux/tee.h | 9 +++++++++
4 files changed, 42 insertions(+), 3 deletions(-)
--
2.7.4
There are use-cases where user-space shouldn't be allowed to communicate
directly with a TEE device which is dedicated to provide a specific
service for a kernel client. So add a private login method for kernel
clients and disallow user-space to open-session using GP implementation
defined login method range: (0x80000000 - 0xBFFFFFFF).
Signed-off-by: Sumit Garg <[email protected]>
---
drivers/tee/tee_core.c | 7 +++++++
include/uapi/linux/tee.h | 9 +++++++++
2 files changed, 16 insertions(+)
diff --git a/drivers/tee/tee_core.c b/drivers/tee/tee_core.c
index 37d22e3..13a016e 100644
--- a/drivers/tee/tee_core.c
+++ b/drivers/tee/tee_core.c
@@ -334,6 +334,13 @@ static int tee_ioctl_open_session(struct tee_context *ctx,
goto out;
}
+ if (arg.clnt_login >= TEE_IOCTL_LOGIN_REE_KERNEL_MIN &&
+ arg.clnt_login <= TEE_IOCTL_LOGIN_REE_KERNEL_MAX) {
+ pr_debug("login method not allowed for user-space client\n");
+ rc = -EPERM;
+ goto out;
+ }
+
rc = ctx->teedev->desc->ops->open_session(ctx, &arg, params);
if (rc)
goto out;
diff --git a/include/uapi/linux/tee.h b/include/uapi/linux/tee.h
index 6596f3a..b619f37 100644
--- a/include/uapi/linux/tee.h
+++ b/include/uapi/linux/tee.h
@@ -173,6 +173,15 @@ struct tee_ioctl_buf_data {
#define TEE_IOCTL_LOGIN_APPLICATION 4
#define TEE_IOCTL_LOGIN_USER_APPLICATION 5
#define TEE_IOCTL_LOGIN_GROUP_APPLICATION 6
+/*
+ * Disallow user-space to use GP implementation specific login
+ * method range (0x80000000 - 0xBFFFFFFF). This range is rather
+ * being reserved for REE kernel clients or TEE implementation.
+ */
+#define TEE_IOCTL_LOGIN_REE_KERNEL_MIN 0x80000000
+#define TEE_IOCTL_LOGIN_REE_KERNEL_MAX 0xBFFFFFFF
+/* Private login method for REE kernel clients */
+#define TEE_IOCTL_LOGIN_REE_KERNEL 0x80000000
/**
* struct tee_ioctl_param - parameter
--
2.7.4
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 <[email protected]>
---
drivers/tee/tee_shm.c | 28 +++++++++++++++++++++++++---
include/linux/tee_drv.h | 1 +
2 files changed, 26 insertions(+), 3 deletions(-)
diff --git a/drivers/tee/tee_shm.c b/drivers/tee/tee_shm.c
index 937ac5a..a6c75a4 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)
@@ -217,14 +218,15 @@ struct tee_shm *tee_shm_register(struct tee_context *ctx, unsigned long addr,
size_t length, u32 flags)
{
struct tee_device *teedev = ctx->teedev;
- const u32 req_flags = TEE_SHM_DMA_BUF | TEE_SHM_USER_MAPPED;
+ const u32 req_user_flags = TEE_SHM_DMA_BUF | TEE_SHM_USER_MAPPED;
+ const u32 req_kernel_flags = TEE_SHM_DMA_BUF | TEE_SHM_KERNEL_MAPPED;
struct tee_shm *shm;
void *ret;
int rc;
int num_pages;
unsigned long start;
- if (flags != req_flags)
+ if (flags != req_user_flags && flags != req_kernel_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
Hi Jens,
On Fri, 27 Mar 2020 at 11:00, Sumit Garg <[email protected]> wrote:
>
> Earlier this patch-set was part of TEE Trusted keys patch-set [1]. But
> since these are completely independent enhancements for TEE kernel
> client interface which can be merged separately while TEE Trusted keys
> discussions are ongoing.
>
> Patch #1 enables support for registered kernel shared memory with TEE.
>
> Patch #2 enables support for private kernel login method required for
> cases like trusted keys where we don't wan't user-space to directly
> access TEE service.
>
> [1] https://lkml.org/lkml/2019/10/31/430
>
> Changes in v6:
> - Reserve only half of GP implementation defined range for kernel space.
>
> Changes in v5:
> - Misc. renaming of variables.
>
> Sumit Garg (2):
> tee: enable support to register kernel memory
> tee: add private login method for kernel clients
>
In case we don't have any further comments, would you like to pick up these?
-Sumit
> drivers/tee/tee_core.c | 7 +++++++
> drivers/tee/tee_shm.c | 28 +++++++++++++++++++++++++---
> include/linux/tee_drv.h | 1 +
> include/uapi/linux/tee.h | 9 +++++++++
> 4 files changed, 42 insertions(+), 3 deletions(-)
>
> --
> 2.7.4
>
On 3/27/20 6:29 AM, Sumit Garg wrote:
> There are use-cases where user-space shouldn't be allowed to communicate
> directly with a TEE device which is dedicated to provide a specific
> service for a kernel client. So add a private login method for kernel
> clients and disallow user-space to open-session using GP implementation
> defined login method range: (0x80000000 - 0xBFFFFFFF).
>
> Signed-off-by: Sumit Garg <[email protected]>
> ---
> drivers/tee/tee_core.c | 7 +++++++
> include/uapi/linux/tee.h | 9 +++++++++
> 2 files changed, 16 insertions(+)
Reviewed-by: Jerome Forissier <[email protected]>
Thanks,
--
Jerome
Hi Sumit,
On Fri, Apr 17, 2020 at 12:45 PM Sumit Garg <[email protected]> wrote:
>
> Hi Jens,
>
> On Fri, 27 Mar 2020 at 11:00, Sumit Garg <[email protected]> wrote:
> >
> > Earlier this patch-set was part of TEE Trusted keys patch-set [1]. But
> > since these are completely independent enhancements for TEE kernel
> > client interface which can be merged separately while TEE Trusted keys
> > discussions are ongoing.
> >
> > Patch #1 enables support for registered kernel shared memory with TEE.
> >
> > Patch #2 enables support for private kernel login method required for
> > cases like trusted keys where we don't wan't user-space to directly
> > access TEE service.
> >
> > [1] https://lkml.org/lkml/2019/10/31/430
> >
> > Changes in v6:
> > - Reserve only half of GP implementation defined range for kernel space.
> >
> > Changes in v5:
> > - Misc. renaming of variables.
> >
> > Sumit Garg (2):
> > tee: enable support to register kernel memory
> > tee: add private login method for kernel clients
> >
>
> In case we don't have any further comments, would you like to pick up these?
Thanks for the reminder. I'm picking this up.
Jerome, it's not too late to provide a tag if you like.
Cheers,
Jens