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tee: Remove call to get_kernel_pages() 

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>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Sumit Garg <sumit.garg@linaro.org>
Signed-off-by: Jens Wiklander <jens.wiklander@linaro.org>
This commit is contained in:
Ira Weiny 2023-02-03 20:06:34 -08:00 committed by Jens Wiklander
parent c83900393a
commit 0249a75b36
1 changed files with 8 additions and 13 deletions
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21
drivers/tee/tee_shm.c
View File

@ -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)