On Mon, Jun 24, 2019 at 04:32:55PM +0200, Andrey Konovalov wrote:
This patch is a part of a series that extends 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: Felix Kuehling Felix.Kuehling@amd.com Acked-by: Felix Kuehling Felix.Kuehling@amd.com Signed-off-by: Andrey Konovalov andreyknvl@google.com
Reviewed-by: Kees Cook keescook@chromium.org
-Kees
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;
2.22.0.410.gd8fdbe21b5-goog