On 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@xxxxxxxxxx> > Cc: Al Viro <viro@xxxxxxxxxxxxxxxxxx> > Cc: "Fabio M. De Francesco" <fmdefrancesco@xxxxxxxxx> > Cc: Christoph Hellwig <hch@xxxxxx> > Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx> > Signed-off-by: Ira Weiny <ira.weiny@xxxxxxxxx> > > --- > 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
