[PATCH RFC 15/19] media: pci/ivtv: remove FOLL_FORCE usage

From: David Hildenbrand <david@redhat.com>
To: linux-kernel@vger.kernel.org
Cc: linux-mm@kvack.org, etnaviv@lists.freedesktop.org,
	dri-devel@lists.freedesktop.org,
	linux-arm-kernel@lists.infradead.org,
	linux-samsung-soc@vger.kernel.org, linux-rdma@vger.kernel.org,
	linux-media@vger.kernel.org, linux-kselftest@vger.kernel.org,
	David Hildenbrand <david@redhat.com>,
	Linus Torvalds <torvalds@linux-foundation.org>,
	Andrew Morton <akpm@linux-foundation.org>,
	Jason Gunthorpe <jgg@ziepe.ca>,
	John Hubbard <jhubbard@nvidia.com>, Peter Xu <peterx@redhat.com>,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	Andrea Arcangeli <aarcange@redhat.com>,
	Hugh Dickins <hughd@google.com>, Nadav Amit <namit@vmware.com>,
	Vlastimil Babka <vbabka@suse.cz>,
	Matthew Wilcox <willy@infradead.org>,
	Mike Kravetz <mike.kravetz@oracle.com>,
	Muchun Song <songmuchun@bytedance.com>,
	Lucas Stach <l.stach@pengutronix.de>,
	David Airlie <airlied@gmail.com>,
	Oded Gabbay <ogabbay@kernel.org>, Arnd Bergmann <arnd@arndb.de>,
	Andy Walls <awalls@md.metrocast.net>,
	Mauro Carvalho Chehab <mchehab@kernel.org>
Subject: [PATCH RFC 15/19] media: pci/ivtv: remove FOLL_FORCE usage
Date: Mon,  7 Nov 2022 17:17:36 +0100	[thread overview]
Message-ID: <20221107161740.144456-16-david@redhat.com> (raw)
In-Reply-To: <20221107161740.144456-1-david@redhat.com>

FOLL_FORCE is really only for debugger access. R/O pinning a page is
supposed to fail if the VMA misses proper access permissions (no VM_READ).

Let's just remove FOLL_FORCE usage here; there would have to be a pretty
good reason to allow arbitrary drivers to R/O pin pages in a PROT_NONE
VMA. Most probably, FOLL_FORCE usage is just some legacy leftover.

Cc: Andy Walls <awalls@md.metrocast.net>
Cc: Mauro Carvalho Chehab <mchehab@kernel.org>
Signed-off-by: David Hildenbrand <david@redhat.com>
---
 drivers/media/pci/ivtv/ivtv-udma.c | 2 +-
 drivers/media/pci/ivtv/ivtv-yuv.c  | 5 ++---
 2 files changed, 3 insertions(+), 4 deletions(-)

diff --git a/drivers/media/pci/ivtv/ivtv-udma.c b/drivers/media/pci/ivtv/ivtv-udma.c
index 210be8290f24..99b9f55ca829 100644
--- a/drivers/media/pci/ivtv/ivtv-udma.c
+++ b/drivers/media/pci/ivtv/ivtv-udma.c
@@ -115,7 +115,7 @@ int ivtv_udma_setup(struct ivtv *itv, unsigned long ivtv_dest_addr,
 
 	/* Pin user pages for DMA Xfer */
 	err = pin_user_pages_unlocked(user_dma.uaddr, user_dma.page_count,
-			dma->map, FOLL_FORCE);
+			dma->map, 0);
 
 	if (user_dma.page_count != err) {
 		IVTV_DEBUG_WARN("failed to map user pages, returned %d instead of %d\n",
diff --git a/drivers/media/pci/ivtv/ivtv-yuv.c b/drivers/media/pci/ivtv/ivtv-yuv.c
index 4ba10c34a16a..582146f8d70d 100644
--- a/drivers/media/pci/ivtv/ivtv-yuv.c
+++ b/drivers/media/pci/ivtv/ivtv-yuv.c
@@ -63,12 +63,11 @@ static int ivtv_yuv_prep_user_dma(struct ivtv *itv, struct ivtv_user_dma *dma,
 
 	/* Pin user pages for DMA Xfer */
 	y_pages = pin_user_pages_unlocked(y_dma.uaddr,
-			y_dma.page_count, &dma->map[0], FOLL_FORCE);
+			y_dma.page_count, &dma->map[0], 0);
 	uv_pages = 0; /* silence gcc. value is set and consumed only if: */
 	if (y_pages == y_dma.page_count) {
 		uv_pages = pin_user_pages_unlocked(uv_dma.uaddr,
-				uv_dma.page_count, &dma->map[y_pages],
-				FOLL_FORCE);
+				uv_dma.page_count, &dma->map[y_pages], 0);
 	}
 
 	if (y_pages != y_dma.page_count || uv_pages != uv_dma.page_count) {
-- 
2.38.1


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