[Patch v3 2/7] tee: enable support to register kernel memory
From: Sumit Garg <hidden>
Date: 2019-10-31 13:59:51
Also in:
keyrings, linux-arm-kernel, linux-doc, linux-integrity, lkml
Subsystem:
tee subsystem, the rest · Maintainers:
Jens Wiklander, Linus Torvalds
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 <redacted> --- 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 09ddcd0..1ec1577 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)
@@ -224,13 +225,14 @@ 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; 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))
@@ -265,7 +267,27 @@ 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