Re: [PATCH] drm/amdgpu: Fix potential race processing vm->freed
Am 06.02.23 um 19:21 schrieb Rob Clark:
On Mon, Feb 6, 2023 at 8:05 AM Christian König wrote:
Am 06.02.23 um 16:52 schrieb Rob Clark:
On Mon, Feb 6, 2023 at 2:15 AM Christian König wrote:
Am 03.02.23 um 19:10 schrieb Rob Clark:
From: Rob Clark
If userspace calls the AMDGPU_CS ioctl from multiple threads, because
the vm is global to the drm_file, you can end up with multiple threads
racing in amdgpu_vm_clear_freed(). So the freed list should be
protected with the status_lock, similar to other vm lists.
Well this is nonsense. To process the freed list the VM root PD lock
must be held anyway.
If we have a call path where this isn't true then we have a major bug at
a different place here.
I'm not super familiar w/ the amdgpu cs parser stuff, but the only
thing that I'm seeing that protects things is the bo_list_mutex and it
isn't clear to me that this is 1:1 with the vm (it looks like it is
not).
Do you have a backtrace?
Take a look at the reservation object of vm->root.bo. This should always
be locked first before doing *anything* in a CS.
If that isn't the case we have a much worse problem.
In this case, maybe an dma_resv_assert_held() would be a good idea?
We should already have that. Which makes me really wonder what the heck
is going on here.
Christian.
BR,
-R
(I cc'd you on the bug report, jfyi)
I unfortunately only get a permission denied when I try to access that one.
Regards,
Christian.
BR,
-R
Regards,
Christian.
Fixes: d38ceaf99ed0 ("drm/amdgpu: add core driver (v4)")
Signed-off-by: Rob Clark
---
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c | 33 ++
1 file changed, 29 insertions(+), 4 deletions(-)
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
index b9441ab457ea..aeed7bc1512f 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
@@ -1240,10 +1240,19 @@ int amdgpu_vm_clear_freed(struct amdgpu_device *adev,
struct amdgpu_bo_va_mapping *mapping;
uint64_t init_pte_value = 0;
struct dma_fence *f = NULL;
+ struct list_head freed;
int r;
- while (!list_empty(&vm->freed)) {
- mapping = list_first_entry(&vm->freed,
+ /*
+ * Move the contents of the VM's freed list to a local list
+ * that we can iterate without racing against other threads:
+ */
+ spin_lock(&vm->status_lock);
+ list_replace_init(&vm->freed, &freed);
+ spin_unlock(&vm->status_lock);
+
+ while (!list_empty(&freed)) {
+ mapping = list_first_entry(&freed,
struct amdgpu_bo_va_mapping, list);
list_del(&mapping->list);
@@ -1258,6 +1267,15 @@ int amdgpu_vm_clear_freed(struct amdgpu_device *adev,
amdgpu_vm_free_mapping(adev, vm, mapping, f);
if (r) {
dma_fence_put(f);
+
+ /*
+ * Move any unprocessed mappings back to the freed
+ * list:
+ */
+ spin_lock(&vm->status_lock);
+ list_splice_tail(&freed, &vm->freed);
+ spin_unlock(&vm->status_lock);
+
return r;
}
}
@@ -1583,11 +1601,14 @@ int amdgpu_vm_bo_unmap(struct amdgpu_device *adev,
mapping->bo_va = NULL;
trace_amdgpu_vm_bo_unmap(bo_va, mapping);
- if (valid)
+ if (valid) {
+ spin_lock(&vm->status_lock);
list_add(&mapping->list, &vm->freed);
- else
+ spin_unlock(&vm->status_lock);
+ } else {
amdgpu_vm_free_mapping(adev, vm, mapping,
bo_va->last_pt_update);
+ }
return 0;
}
@@ -1671,7 +1692,9 @@ int amdgpu_vm_bo_clear_mappings(struct amdgpu_device
*adev,
tmp->last = eaddr;
tmp->bo_va = NULL;
+ spin_lock(&vm->status_lock);
list_add(&tmp->list, &vm->freed);
+ spin_unlock(&vm->status_lock);
trace_amdgpu_vm_bo_unmap(NULL, tmp);
}
@@ -1788,7 +1811,9 @@ void amdgpu_vm_bo_del(struct amdgpu_device *adev,
amdgpu_vm_it_remove(mapping, &vm->va);
mapping->bo_va = NULL;
trace_amdgpu_vm_bo_unmap(bo_va, mapping);
+ spin_lock(&vm->status_lock);
list_add(&mapping->list, &vm->freed);
+ spin_unlock(&vm->status_lock);
}
list_for_each_entry_safe(mapping, next, &bo_va->invalids, list) {
list_del(&mapping->list);
Re: [PATCH] drm/amdgpu: Fix potential race processing vm->freed
On Mon, Feb 6, 2023 at 8:05 AM Christian König wrote:
>
> Am 06.02.23 um 16:52 schrieb Rob Clark:
> > On Mon, Feb 6, 2023 at 2:15 AM Christian König
> > wrote:
> >> Am 03.02.23 um 19:10 schrieb Rob Clark:
> >>> From: Rob Clark
> >>>
> >>> If userspace calls the AMDGPU_CS ioctl from multiple threads, because
> >>> the vm is global to the drm_file, you can end up with multiple threads
> >>> racing in amdgpu_vm_clear_freed(). So the freed list should be
> >>> protected with the status_lock, similar to other vm lists.
> >> Well this is nonsense. To process the freed list the VM root PD lock
> >> must be held anyway.
> >>
> >> If we have a call path where this isn't true then we have a major bug at
> >> a different place here.
> > I'm not super familiar w/ the amdgpu cs parser stuff, but the only
> > thing that I'm seeing that protects things is the bo_list_mutex and it
> > isn't clear to me that this is 1:1 with the vm (it looks like it is
> > not).
>
> Do you have a backtrace?
>
> Take a look at the reservation object of vm->root.bo. This should always
> be locked first before doing *anything* in a CS.
>
> If that isn't the case we have a much worse problem.
In this case, maybe an dma_resv_assert_held() would be a good idea?
BR,
-R
> > (I cc'd you on the bug report, jfyi)
>
> I unfortunately only get a permission denied when I try to access that one.
>
> Regards,
> Christian.
>
> >
> > BR,
> > -R
> >
> >> Regards,
> >> Christian.
> >>
> >>> Fixes: d38ceaf99ed0 ("drm/amdgpu: add core driver (v4)")
> >>> Signed-off-by: Rob Clark
> >>> ---
> >>>drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c | 33 ++
> >>>1 file changed, 29 insertions(+), 4 deletions(-)
> >>>
> >>> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
> >>> b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
> >>> index b9441ab457ea..aeed7bc1512f 100644
> >>> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
> >>> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
> >>> @@ -1240,10 +1240,19 @@ int amdgpu_vm_clear_freed(struct amdgpu_device
> >>> *adev,
> >>>struct amdgpu_bo_va_mapping *mapping;
> >>>uint64_t init_pte_value = 0;
> >>>struct dma_fence *f = NULL;
> >>> + struct list_head freed;
> >>>int r;
> >>>
> >>> - while (!list_empty(&vm->freed)) {
> >>> - mapping = list_first_entry(&vm->freed,
> >>> + /*
> >>> + * Move the contents of the VM's freed list to a local list
> >>> + * that we can iterate without racing against other threads:
> >>> + */
> >>> + spin_lock(&vm->status_lock);
> >>> + list_replace_init(&vm->freed, &freed);
> >>> + spin_unlock(&vm->status_lock);
> >>> +
> >>> + while (!list_empty(&freed)) {
> >>> + mapping = list_first_entry(&freed,
> >>>struct amdgpu_bo_va_mapping, list);
> >>>list_del(&mapping->list);
> >>>
> >>> @@ -1258,6 +1267,15 @@ int amdgpu_vm_clear_freed(struct amdgpu_device
> >>> *adev,
> >>>amdgpu_vm_free_mapping(adev, vm, mapping, f);
> >>>if (r) {
> >>>dma_fence_put(f);
> >>> +
> >>> + /*
> >>> + * Move any unprocessed mappings back to the freed
> >>> + * list:
> >>> + */
> >>> + spin_lock(&vm->status_lock);
> >>> + list_splice_tail(&freed, &vm->freed);
> >>> + spin_unlock(&vm->status_lock);
> >>> +
> >>>return r;
> >>>}
> >>>}
> >>> @@ -1583,11 +1601,14 @@ int amdgpu_vm_bo_unmap(struct amdgpu_device *adev,
> >>>mapping->bo_va = NULL;
> >>>trace_amdgpu_vm_bo_unmap(bo_va, mapping);
> >>>
> >>> - if (valid)
> >>> + if (valid) {
> >>> + spin_lock(&vm->status_lock);
> >>>list_add(&mapping->list, &vm->freed);
> >>> - else
> >>> + spin_unlock(&vm->status_lock);
> >>> + } else {
> >>>amdgpu_vm_free_mapping(adev, vm, mapping,
> >>> bo_va->last_pt_update);
> >>> + }
> >>>
> >>>return 0;
> >>>}
> >>> @@ -1671,7 +1692,9 @@ int amdgpu_vm_bo_clear_mappings(struct
> >>> amdgpu_device *adev,
> >>>tmp->last = eaddr;
> >>>
> >>>tmp->bo_va = NULL;
> >>> + spin_lock(&vm->status_lock);
> >>>list_add(&tmp->list, &vm->freed);
> >>> + spin_unlock(&vm->status_lock);
> >>>trace_amdgpu_vm_bo_unmap(NULL, tmp);
> >>>}
> >>>
> >>> @@ -1788,7 +1811,9 @@ void amdgpu_vm_bo_del(struct amdgpu_device *adev,
> >>>amdgpu_vm_it_remove(mapping, &vm->va);
> >>>mapping->bo_va = NULL;
> >>>trace_amdgpu_vm_bo_unmap(bo_va, mapping);
> >>> + spin_lock(&vm->status_lock);
> >>>list_add(&mapping->list, &vm->freed);
> >>> + spin_unlock(&vm->s
Re: [PATCH] drm/amdgpu: Fix potential race processing vm->freed
Am 06.02.23 um 16:52 schrieb Rob Clark:
On Mon, Feb 6, 2023 at 2:15 AM Christian König wrote:
Am 03.02.23 um 19:10 schrieb Rob Clark:
From: Rob Clark
If userspace calls the AMDGPU_CS ioctl from multiple threads, because
the vm is global to the drm_file, you can end up with multiple threads
racing in amdgpu_vm_clear_freed(). So the freed list should be
protected with the status_lock, similar to other vm lists.
Well this is nonsense. To process the freed list the VM root PD lock
must be held anyway.
If we have a call path where this isn't true then we have a major bug at
a different place here.
I'm not super familiar w/ the amdgpu cs parser stuff, but the only
thing that I'm seeing that protects things is the bo_list_mutex and it
isn't clear to me that this is 1:1 with the vm (it looks like it is
not).
Do you have a backtrace?
Take a look at the reservation object of vm->root.bo. This should always
be locked first before doing *anything* in a CS.
If that isn't the case we have a much worse problem.
(I cc'd you on the bug report, jfyi)
I unfortunately only get a permission denied when I try to access that one.
Regards,
Christian.
BR,
-R
Regards,
Christian.
Fixes: d38ceaf99ed0 ("drm/amdgpu: add core driver (v4)")
Signed-off-by: Rob Clark
---
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c | 33 ++
1 file changed, 29 insertions(+), 4 deletions(-)
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
index b9441ab457ea..aeed7bc1512f 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
@@ -1240,10 +1240,19 @@ int amdgpu_vm_clear_freed(struct amdgpu_device *adev,
struct amdgpu_bo_va_mapping *mapping;
uint64_t init_pte_value = 0;
struct dma_fence *f = NULL;
+ struct list_head freed;
int r;
- while (!list_empty(&vm->freed)) {
- mapping = list_first_entry(&vm->freed,
+ /*
+ * Move the contents of the VM's freed list to a local list
+ * that we can iterate without racing against other threads:
+ */
+ spin_lock(&vm->status_lock);
+ list_replace_init(&vm->freed, &freed);
+ spin_unlock(&vm->status_lock);
+
+ while (!list_empty(&freed)) {
+ mapping = list_first_entry(&freed,
struct amdgpu_bo_va_mapping, list);
list_del(&mapping->list);
@@ -1258,6 +1267,15 @@ int amdgpu_vm_clear_freed(struct amdgpu_device *adev,
amdgpu_vm_free_mapping(adev, vm, mapping, f);
if (r) {
dma_fence_put(f);
+
+ /*
+ * Move any unprocessed mappings back to the freed
+ * list:
+ */
+ spin_lock(&vm->status_lock);
+ list_splice_tail(&freed, &vm->freed);
+ spin_unlock(&vm->status_lock);
+
return r;
}
}
@@ -1583,11 +1601,14 @@ int amdgpu_vm_bo_unmap(struct amdgpu_device *adev,
mapping->bo_va = NULL;
trace_amdgpu_vm_bo_unmap(bo_va, mapping);
- if (valid)
+ if (valid) {
+ spin_lock(&vm->status_lock);
list_add(&mapping->list, &vm->freed);
- else
+ spin_unlock(&vm->status_lock);
+ } else {
amdgpu_vm_free_mapping(adev, vm, mapping,
bo_va->last_pt_update);
+ }
return 0;
}
@@ -1671,7 +1692,9 @@ int amdgpu_vm_bo_clear_mappings(struct amdgpu_device
*adev,
tmp->last = eaddr;
tmp->bo_va = NULL;
+ spin_lock(&vm->status_lock);
list_add(&tmp->list, &vm->freed);
+ spin_unlock(&vm->status_lock);
trace_amdgpu_vm_bo_unmap(NULL, tmp);
}
@@ -1788,7 +1811,9 @@ void amdgpu_vm_bo_del(struct amdgpu_device *adev,
amdgpu_vm_it_remove(mapping, &vm->va);
mapping->bo_va = NULL;
trace_amdgpu_vm_bo_unmap(bo_va, mapping);
+ spin_lock(&vm->status_lock);
list_add(&mapping->list, &vm->freed);
+ spin_unlock(&vm->status_lock);
}
list_for_each_entry_safe(mapping, next, &bo_va->invalids, list) {
list_del(&mapping->list);
Re: [PATCH] drm/amdgpu: Fix potential race processing vm->freed
On Mon, Feb 6, 2023 at 2:15 AM Christian König wrote:
>
> Am 03.02.23 um 19:10 schrieb Rob Clark:
> > From: Rob Clark
> >
> > If userspace calls the AMDGPU_CS ioctl from multiple threads, because
> > the vm is global to the drm_file, you can end up with multiple threads
> > racing in amdgpu_vm_clear_freed(). So the freed list should be
> > protected with the status_lock, similar to other vm lists.
>
> Well this is nonsense. To process the freed list the VM root PD lock
> must be held anyway.
>
> If we have a call path where this isn't true then we have a major bug at
> a different place here.
I'm not super familiar w/ the amdgpu cs parser stuff, but the only
thing that I'm seeing that protects things is the bo_list_mutex and it
isn't clear to me that this is 1:1 with the vm (it looks like it is
not).
(I cc'd you on the bug report, jfyi)
BR,
-R
>
> Regards,
> Christian.
>
> >
> > Fixes: d38ceaf99ed0 ("drm/amdgpu: add core driver (v4)")
> > Signed-off-by: Rob Clark
> > ---
> > drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c | 33 ++
> > 1 file changed, 29 insertions(+), 4 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
> > b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
> > index b9441ab457ea..aeed7bc1512f 100644
> > --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
> > +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
> > @@ -1240,10 +1240,19 @@ int amdgpu_vm_clear_freed(struct amdgpu_device
> > *adev,
> > struct amdgpu_bo_va_mapping *mapping;
> > uint64_t init_pte_value = 0;
> > struct dma_fence *f = NULL;
> > + struct list_head freed;
> > int r;
> >
> > - while (!list_empty(&vm->freed)) {
> > - mapping = list_first_entry(&vm->freed,
> > + /*
> > + * Move the contents of the VM's freed list to a local list
> > + * that we can iterate without racing against other threads:
> > + */
> > + spin_lock(&vm->status_lock);
> > + list_replace_init(&vm->freed, &freed);
> > + spin_unlock(&vm->status_lock);
> > +
> > + while (!list_empty(&freed)) {
> > + mapping = list_first_entry(&freed,
> > struct amdgpu_bo_va_mapping, list);
> > list_del(&mapping->list);
> >
> > @@ -1258,6 +1267,15 @@ int amdgpu_vm_clear_freed(struct amdgpu_device *adev,
> > amdgpu_vm_free_mapping(adev, vm, mapping, f);
> > if (r) {
> > dma_fence_put(f);
> > +
> > + /*
> > + * Move any unprocessed mappings back to the freed
> > + * list:
> > + */
> > + spin_lock(&vm->status_lock);
> > + list_splice_tail(&freed, &vm->freed);
> > + spin_unlock(&vm->status_lock);
> > +
> > return r;
> > }
> > }
> > @@ -1583,11 +1601,14 @@ int amdgpu_vm_bo_unmap(struct amdgpu_device *adev,
> > mapping->bo_va = NULL;
> > trace_amdgpu_vm_bo_unmap(bo_va, mapping);
> >
> > - if (valid)
> > + if (valid) {
> > + spin_lock(&vm->status_lock);
> > list_add(&mapping->list, &vm->freed);
> > - else
> > + spin_unlock(&vm->status_lock);
> > + } else {
> > amdgpu_vm_free_mapping(adev, vm, mapping,
> > bo_va->last_pt_update);
> > + }
> >
> > return 0;
> > }
> > @@ -1671,7 +1692,9 @@ int amdgpu_vm_bo_clear_mappings(struct amdgpu_device
> > *adev,
> > tmp->last = eaddr;
> >
> > tmp->bo_va = NULL;
> > + spin_lock(&vm->status_lock);
> > list_add(&tmp->list, &vm->freed);
> > + spin_unlock(&vm->status_lock);
> > trace_amdgpu_vm_bo_unmap(NULL, tmp);
> > }
> >
> > @@ -1788,7 +1811,9 @@ void amdgpu_vm_bo_del(struct amdgpu_device *adev,
> > amdgpu_vm_it_remove(mapping, &vm->va);
> > mapping->bo_va = NULL;
> > trace_amdgpu_vm_bo_unmap(bo_va, mapping);
> > + spin_lock(&vm->status_lock);
> > list_add(&mapping->list, &vm->freed);
> > + spin_unlock(&vm->status_lock);
> > }
> > list_for_each_entry_safe(mapping, next, &bo_va->invalids, list) {
> > list_del(&mapping->list);
>
Re: [PATCH] drm/amdgpu: Fix potential race processing vm->freed
Am 03.02.23 um 19:10 schrieb Rob Clark:
From: Rob Clark
If userspace calls the AMDGPU_CS ioctl from multiple threads, because
the vm is global to the drm_file, you can end up with multiple threads
racing in amdgpu_vm_clear_freed(). So the freed list should be
protected with the status_lock, similar to other vm lists.
Well this is nonsense. To process the freed list the VM root PD lock
must be held anyway.
If we have a call path where this isn't true then we have a major bug at
a different place here.
Regards,
Christian.
Fixes: d38ceaf99ed0 ("drm/amdgpu: add core driver (v4)")
Signed-off-by: Rob Clark
---
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c | 33 ++
1 file changed, 29 insertions(+), 4 deletions(-)
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
index b9441ab457ea..aeed7bc1512f 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
@@ -1240,10 +1240,19 @@ int amdgpu_vm_clear_freed(struct amdgpu_device *adev,
struct amdgpu_bo_va_mapping *mapping;
uint64_t init_pte_value = 0;
struct dma_fence *f = NULL;
+ struct list_head freed;
int r;
- while (!list_empty(&vm->freed)) {
- mapping = list_first_entry(&vm->freed,
+ /*
+* Move the contents of the VM's freed list to a local list
+* that we can iterate without racing against other threads:
+*/
+ spin_lock(&vm->status_lock);
+ list_replace_init(&vm->freed, &freed);
+ spin_unlock(&vm->status_lock);
+
+ while (!list_empty(&freed)) {
+ mapping = list_first_entry(&freed,
struct amdgpu_bo_va_mapping, list);
list_del(&mapping->list);
@@ -1258,6 +1267,15 @@ int amdgpu_vm_clear_freed(struct amdgpu_device *adev,
amdgpu_vm_free_mapping(adev, vm, mapping, f);
if (r) {
dma_fence_put(f);
+
+ /*
+* Move any unprocessed mappings back to the freed
+* list:
+*/
+ spin_lock(&vm->status_lock);
+ list_splice_tail(&freed, &vm->freed);
+ spin_unlock(&vm->status_lock);
+
return r;
}
}
@@ -1583,11 +1601,14 @@ int amdgpu_vm_bo_unmap(struct amdgpu_device *adev,
mapping->bo_va = NULL;
trace_amdgpu_vm_bo_unmap(bo_va, mapping);
- if (valid)
+ if (valid) {
+ spin_lock(&vm->status_lock);
list_add(&mapping->list, &vm->freed);
- else
+ spin_unlock(&vm->status_lock);
+ } else {
amdgpu_vm_free_mapping(adev, vm, mapping,
bo_va->last_pt_update);
+ }
return 0;
}
@@ -1671,7 +1692,9 @@ int amdgpu_vm_bo_clear_mappings(struct amdgpu_device
*adev,
tmp->last = eaddr;
tmp->bo_va = NULL;
+ spin_lock(&vm->status_lock);
list_add(&tmp->list, &vm->freed);
+ spin_unlock(&vm->status_lock);
trace_amdgpu_vm_bo_unmap(NULL, tmp);
}
@@ -1788,7 +1811,9 @@ void amdgpu_vm_bo_del(struct amdgpu_device *adev,
amdgpu_vm_it_remove(mapping, &vm->va);
mapping->bo_va = NULL;
trace_amdgpu_vm_bo_unmap(bo_va, mapping);
+ spin_lock(&vm->status_lock);
list_add(&mapping->list, &vm->freed);
+ spin_unlock(&vm->status_lock);
}
list_for_each_entry_safe(mapping, next, &bo_va->invalids, list) {
list_del(&mapping->list);
[PATCH] drm/amdgpu: Fix potential race processing vm->freed
From: Rob Clark
If userspace calls the AMDGPU_CS ioctl from multiple threads, because
the vm is global to the drm_file, you can end up with multiple threads
racing in amdgpu_vm_clear_freed(). So the freed list should be
protected with the status_lock, similar to other vm lists.
Fixes: d38ceaf99ed0 ("drm/amdgpu: add core driver (v4)")
Signed-off-by: Rob Clark
---
drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c | 33 ++
1 file changed, 29 insertions(+), 4 deletions(-)
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
index b9441ab457ea..aeed7bc1512f 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
@@ -1240,10 +1240,19 @@ int amdgpu_vm_clear_freed(struct amdgpu_device *adev,
struct amdgpu_bo_va_mapping *mapping;
uint64_t init_pte_value = 0;
struct dma_fence *f = NULL;
+ struct list_head freed;
int r;
- while (!list_empty(&vm->freed)) {
- mapping = list_first_entry(&vm->freed,
+ /*
+* Move the contents of the VM's freed list to a local list
+* that we can iterate without racing against other threads:
+*/
+ spin_lock(&vm->status_lock);
+ list_replace_init(&vm->freed, &freed);
+ spin_unlock(&vm->status_lock);
+
+ while (!list_empty(&freed)) {
+ mapping = list_first_entry(&freed,
struct amdgpu_bo_va_mapping, list);
list_del(&mapping->list);
@@ -1258,6 +1267,15 @@ int amdgpu_vm_clear_freed(struct amdgpu_device *adev,
amdgpu_vm_free_mapping(adev, vm, mapping, f);
if (r) {
dma_fence_put(f);
+
+ /*
+* Move any unprocessed mappings back to the freed
+* list:
+*/
+ spin_lock(&vm->status_lock);
+ list_splice_tail(&freed, &vm->freed);
+ spin_unlock(&vm->status_lock);
+
return r;
}
}
@@ -1583,11 +1601,14 @@ int amdgpu_vm_bo_unmap(struct amdgpu_device *adev,
mapping->bo_va = NULL;
trace_amdgpu_vm_bo_unmap(bo_va, mapping);
- if (valid)
+ if (valid) {
+ spin_lock(&vm->status_lock);
list_add(&mapping->list, &vm->freed);
- else
+ spin_unlock(&vm->status_lock);
+ } else {
amdgpu_vm_free_mapping(adev, vm, mapping,
bo_va->last_pt_update);
+ }
return 0;
}
@@ -1671,7 +1692,9 @@ int amdgpu_vm_bo_clear_mappings(struct amdgpu_device
*adev,
tmp->last = eaddr;
tmp->bo_va = NULL;
+ spin_lock(&vm->status_lock);
list_add(&tmp->list, &vm->freed);
+ spin_unlock(&vm->status_lock);
trace_amdgpu_vm_bo_unmap(NULL, tmp);
}
@@ -1788,7 +1811,9 @@ void amdgpu_vm_bo_del(struct amdgpu_device *adev,
amdgpu_vm_it_remove(mapping, &vm->va);
mapping->bo_va = NULL;
trace_amdgpu_vm_bo_unmap(bo_va, mapping);
+ spin_lock(&vm->status_lock);
list_add(&mapping->list, &vm->freed);
+ spin_unlock(&vm->status_lock);
}
list_for_each_entry_safe(mapping, next, &bo_va->invalids, list) {
list_del(&mapping->list);
--
2.38.1
