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disp: msm: sde: prevent custom ioctls from accessing unowned HW

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Early wakeup ioctls from perf HAL driver can access display HW
registers and come as a sideband to atomic commits. Since the
atomic validate checks are not part of this code path it's
possible for HW access to occur during a trusted UI session.
Prevent this whenever the HW is not under this VM's ownership.
Also, move the VM ownership check for the register/deregister
event ioctl to cover both the CRTC and connector events since
new connector events are being added which can access HW.

Change-Id: I39660ae60e7e8f8a405e819c43ec42fbac3f492a
Signed-off-by: Steve Cohen <cohens@codeaurora.org>
This commit is contained in:
Steve Cohen
2021-08-10 17:15:02 -04:00
parent 6bf96605eb
commit 9690b545df
3 changed files with 22 additions and 17 deletions
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1
msm/msm_drv.c
View File

@@ -1627,6 +1627,7 @@ int msm_ioctl_display_hint_ops(struct drm_device *dev, void *data,
SDE_EVT32(display_hint->hint_flags);
/* Any new hint added will require a check for VM ownership before HW is accessed */
if (display_hint->hint_flags == DRM_MSM_DISPLAY_EARLY_WAKEUP_HINT) {
if (!display_hint->data) {
DRM_ERROR("early_wakeup: wrong parameter\n");

11
msm/sde/sde_encoder.c
View File

@@ -4046,9 +4046,15 @@ static void sde_encoder_early_wakeup_work_handler(struct kthread_work *work)
{
struct sde_encoder_virt *sde_enc = container_of(work,
struct sde_encoder_virt, early_wakeup_work);
struct sde_vm_ops *vm_ops;
struct sde_kms *sde_kms = to_sde_kms(ddev_to_msm_kms(sde_enc->base.dev));
if (!sde_enc) {
SDE_ERROR("invalid sde encoder\n");
vm_ops = sde_vm_get_ops(sde_kms);
sde_vm_lock(sde_kms);
if (vm_ops && vm_ops->vm_owns_hw && !vm_ops->vm_owns_hw(sde_kms)) {
sde_vm_unlock(sde_kms);
SDE_DEBUG("skip early wakeup for ENC-%d, HW is owned by other VM\n",
DRMID(&sde_enc->base));
return;
}
@@ -4056,6 +4062,7 @@ static void sde_encoder_early_wakeup_work_handler(struct kthread_work *work)
sde_encoder_resource_control(&sde_enc->base,
SDE_ENC_RC_EVENT_EARLY_WAKEUP);
SDE_ATRACE_END("encoder_early_wakeup");
sde_vm_unlock(sde_kms);
}
void sde_encoder_early_wakeup(struct drm_encoder *drm_enc)

27
msm/sde/sde_kms.c
View File

@@ -5062,9 +5062,9 @@ static int _sde_kms_register_events(struct msm_kms *kms,
struct drm_mode_object *obj, u32 event, bool en)
{
int ret = 0;
struct drm_crtc *crtc = NULL;
struct drm_connector *conn = NULL;
struct sde_kms *sde_kms = NULL;
struct drm_crtc *crtc;
struct drm_connector *conn;
struct sde_kms *sde_kms;
struct sde_vm_ops *vm_ops;
if (!kms || !obj) {
@@ -5073,24 +5073,19 @@ static int _sde_kms_register_events(struct msm_kms *kms,
}
sde_kms = to_sde_kms(kms);
vm_ops = sde_vm_get_ops(sde_kms);
sde_vm_lock(sde_kms);
if (vm_ops && vm_ops->vm_owns_hw && !vm_ops->vm_owns_hw(sde_kms)) {
sde_vm_unlock(sde_kms);
SDE_DEBUG("HW is owned by other VM\n");
return -EACCES;
}
/* check vm ownership, if event registration requires HW access */
switch (obj->type) {
case DRM_MODE_OBJECT_CRTC:
vm_ops = sde_vm_get_ops(sde_kms);
sde_vm_lock(sde_kms);
if (vm_ops && vm_ops->vm_owns_hw
&& !vm_ops->vm_owns_hw(sde_kms)) {
sde_vm_unlock(sde_kms);
SDE_DEBUG("HW is owned by other VM\n");
return -EACCES;
}
crtc = obj_to_crtc(obj);
ret = sde_crtc_register_custom_event(sde_kms, crtc, event, en);
sde_vm_unlock(sde_kms);
break;
case DRM_MODE_OBJECT_CONNECTOR:
conn = obj_to_connector(obj);
@@ -5099,6 +5094,8 @@ static int _sde_kms_register_events(struct msm_kms *kms,
break;
}
sde_vm_unlock(sde_kms);
return ret;
}