[PATCH v16 11/16] drm/radeon, arm64: untag user pointers in radeon_gem_userptr_ioctl

Andrey Konovalov
2019-06-03T16:57:21Z

This patch is a part of a series that extends arm64 kernel ABI to allow to
pass tagged user pointers (with the top byte set to something else other
than 0x00) as syscall arguments.

In radeon_gem_userptr_ioctl() an MMU notifier is set up with a (tagged)
userspace pointer. The untagged address should be used so that MMU
notifiers for the untagged address get correctly matched up with the right
BO. This funcation also calls radeon_ttm_tt_pin_userptr(), which uses
provided user pointers for vma lookups, which can only by done with
untagged pointers.

This patch untags user pointers in radeon_gem_userptr_ioctl().

Suggested-by: Kuehling, Felix <Felix.Kuehling@amd.com>
Acked-by: Felix Kuehling <Felix.Kuehling@amd.com>
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
---
drivers/gpu/drm/radeon/radeon_gem.c | 2 ++
1 file changed, 2 insertions(+)

diff --git a/drivers/gpu/drm/radeon/radeon_gem.c b/drivers/gpu/drm/radeon/radeon_gem.c
index 44617dec8183..90eb78fb5eb2 100644
--- a/drivers/gpu/drm/radeon/radeon_gem.c
+++ b/drivers/gpu/drm/radeon/radeon_gem.c
@@ -291,6 +291,8 @@ int radeon_gem_userptr_ioctl(struct drm_device *dev, void *data,
uint32_t handle;
int r;

+ args->addr = untagged_addr(args->addr);
+
if (offset_in_page(args->addr | args->size))
return -EINVAL;

--
2.22.0.rc1.311.g5d7573a151-goog