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()
Because the pages can't be from highmem get_kernel_pages() boils down to
a get_page() call.
Remove the get_kernel_pages() call and open code the get_page().
In case a highmem page does slip through warn on once for a kmap'ed
address.
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>
---
Changes from v1:
Al/Christoph: Remove kiov altogether
---
drivers/tee/tee_shm.c | 21 ++++++++-------------
1 file changed, 8 insertions(+), 13 deletions(-)
diff --git a/drivers/tee/tee_shm.c b/drivers/tee/tee_shm.c
index 527a6eabc03e..b1c6231defad 100644
--- a/drivers/tee/tee_shm.c
+++ b/drivers/tee/tee_shm.c
@@ -11,6 +11,7 @@
#include <linux/tee_drv.h>
#include <linux/uaccess.h>
#include <linux/uio.h>
+#include <linux/highmem.h>
#include "tee_private.h"
static void shm_put_kernel_pages(struct page **pages, size_t page_count)
@@ -24,26 +25,20 @@ 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;
+ struct page *page;
size_t n;
- int rc;
- if (WARN_ON_ONCE(is_vmalloc_addr((void *)start)))
+ if (WARN_ON_ONCE(is_vmalloc_addr((void *)start) ||
+ is_kmap_addr((void *)start)))
return -EINVAL;
- kiov = kcalloc(page_count, sizeof(*kiov), GFP_KERNEL);
- if (!kiov)
- return -ENOMEM;
-
+ page = virt_to_page(start);
for (n = 0; n < page_count; n++) {
- kiov[n].iov_base = (void *)(start + n * PAGE_SIZE);
- kiov[n].iov_len = PAGE_SIZE;
+ pages[n] = page + n;
+ get_page(pages[n]);
}
- rc = get_kernel_pages(kiov, page_count, 0, pages);
- kfree(kiov);
-
- return rc;
+ return page_count;
}
static void release_registered_pages(struct tee_shm *shm)
--
2.39.1On Fri, Feb 03, 2023 at 08:06:34PM -0800, Ira Weiny wrote:
> 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()
>
> Because the pages can't be from highmem get_kernel_pages() boils down to
> a get_page() call.
>
> Remove the get_kernel_pages() call and open code the get_page().
>
> In case a highmem page does slip through warn on once for a kmap'ed
> address.
>
> 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>
>
> ---
> Changes from v1:
> Al/Christoph: Remove kiov altogether
> ---
> drivers/tee/tee_shm.c | 21 ++++++++-------------
> 1 file changed, 8 insertions(+), 13 deletions(-)
Added to https://git.linaro.org/people/jens.wiklander/linux-tee.git/log/?h=get_kernel_pages-for-v6.4
Thanks,
Jens
>
> diff --git a/drivers/tee/tee_shm.c b/drivers/tee/tee_shm.c
> index 527a6eabc03e..b1c6231defad 100644
> --- a/drivers/tee/tee_shm.c
> +++ b/drivers/tee/tee_shm.c
> @@ -11,6 +11,7 @@
> #include <linux/tee_drv.h>
> #include <linux/uaccess.h>
> #include <linux/uio.h>
> +#include <linux/highmem.h>
> #include "tee_private.h"
>
> static void shm_put_kernel_pages(struct page **pages, size_t page_count)
> @@ -24,26 +25,20 @@ 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;
> + struct page *page;
> size_t n;
> - int rc;
>
> - if (WARN_ON_ONCE(is_vmalloc_addr((void *)start)))
> + if (WARN_ON_ONCE(is_vmalloc_addr((void *)start) ||
> + is_kmap_addr((void *)start)))
> return -EINVAL;
>
> - kiov = kcalloc(page_count, sizeof(*kiov), GFP_KERNEL);
> - if (!kiov)
> - return -ENOMEM;
> -
> + page = virt_to_page(start);
> for (n = 0; n < page_count; n++) {
> - kiov[n].iov_base = (void *)(start + n * PAGE_SIZE);
> - kiov[n].iov_len = PAGE_SIZE;
> + pages[n] = page + n;
> + get_page(pages[n]);
> }
>
> - rc = get_kernel_pages(kiov, page_count, 0, pages);
> - kfree(kiov);
> -
> - return rc;
> + return page_count;
> }
>
> static void release_registered_pages(struct tee_shm *shm)
>
> --
> 2.39.1
On Sat, 4 Feb 2023 at 09:36, Ira Weiny <ira.weiny@intel.com> wrote:
>
> 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()
>
> Because the pages can't be from highmem get_kernel_pages() boils down to
> a get_page() call.
>
> Remove the get_kernel_pages() call and open code the get_page().
>
> In case a highmem page does slip through warn on once for a kmap'ed
> address.
>
> 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>
>
> ---
> Changes from v1:
> Al/Christoph: Remove kiov altogether
> ---
> drivers/tee/tee_shm.c | 21 ++++++++-------------
> 1 file changed, 8 insertions(+), 13 deletions(-)
>
Reviewed-by: Sumit Garg <sumit.garg@linaro.org>
-Sumit
> diff --git a/drivers/tee/tee_shm.c b/drivers/tee/tee_shm.c
> index 527a6eabc03e..b1c6231defad 100644
> --- a/drivers/tee/tee_shm.c
> +++ b/drivers/tee/tee_shm.c
> @@ -11,6 +11,7 @@
> #include <linux/tee_drv.h>
> #include <linux/uaccess.h>
> #include <linux/uio.h>
> +#include <linux/highmem.h>
> #include "tee_private.h"
>
> static void shm_put_kernel_pages(struct page **pages, size_t page_count)
> @@ -24,26 +25,20 @@ 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;
> + struct page *page;
> size_t n;
> - int rc;
>
> - if (WARN_ON_ONCE(is_vmalloc_addr((void *)start)))
> + if (WARN_ON_ONCE(is_vmalloc_addr((void *)start) ||
> + is_kmap_addr((void *)start)))
> return -EINVAL;
>
> - kiov = kcalloc(page_count, sizeof(*kiov), GFP_KERNEL);
> - if (!kiov)
> - return -ENOMEM;
> -
> + page = virt_to_page(start);
> for (n = 0; n < page_count; n++) {
> - kiov[n].iov_base = (void *)(start + n * PAGE_SIZE);
> - kiov[n].iov_len = PAGE_SIZE;
> + pages[n] = page + n;
> + get_page(pages[n]);
> }
>
> - rc = get_kernel_pages(kiov, page_count, 0, pages);
> - kfree(kiov);
> -
> - return rc;
> + return page_count;
> }
>
> static void release_registered_pages(struct tee_shm *shm)
>
> --
> 2.39.1
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