On 2/27/2025 7:55 PM, Christian König wrote:
Am 18.02.25 um 15:53 schrieb Arvind Yadav:
Encountering a taint issue during the unloading of gpu_sched
due to the fence not being released/put. In this context,
amdgpu_vm_clear_freed is responsible for creating a job to
update the page table (PT). It allocates kmem_cache for
drm_sched_fence and returns the finished fence associated
with job->base.s_fence. In case of Usermode queue this finished
fence is added to the timeline sync object through
amdgpu_gem_update_bo_mapping, which is utilized by user
space to ensure the completion of the PT update.
[ 508.900587] =============================================================================
[ 508.900605] BUG drm_sched_fence (Tainted: G N): Objects remaining in drm_sched_fence on __kmem_cache_shutdown()
[ 508.900617] -----------------------------------------------------------------------------
[ 508.900627] Slab 0xffffe0cc04548780 objects=32 used=2 fp=0xffff8ea81521f000 flags=0x17ffffc0000240(workingset|head|node=0|zone=2|lastcpupid=0x1fffff)
[ 508.900645] CPU: 3 UID: 0 PID: 2337 Comm: rmmod Tainted: G N 6.12.0+ #1
[ 508.900651] Tainted: [N]=TEST
[ 508.900653] Hardware name: Gigabyte Technology Co., Ltd. X570 AORUS ELITE/X570 AORUS ELITE, BIOS F34 06/10/2021
[ 508.900656] Call Trace:
[ 508.900659] <TASK>
[ 508.900665] dump_stack_lvl+0x70/0x90
[ 508.900674] dump_stack+0x14/0x20
[ 508.900678] slab_err+0xcb/0x110
[ 508.900687] ? srso_return_thunk+0x5/0x5f
[ 508.900692] ? try_to_grab_pending+0xd3/0x1d0
[ 508.900697] ? srso_return_thunk+0x5/0x5f
[ 508.900701] ? mutex_lock+0x17/0x50
[ 508.900708] __kmem_cache_shutdown+0x144/0x2d0
[ 508.900713] ? flush_rcu_work+0x50/0x60
[ 508.900719] kmem_cache_destroy+0x46/0x1f0
[ 508.900728] drm_sched_fence_slab_fini+0x19/0x970 [gpu_sched]
[ 508.900736] __do_sys_delete_module.constprop.0+0x184/0x320
[ 508.900744] ? srso_return_thunk+0x5/0x5f
[ 508.900747] ? debug_smp_processor_id+0x1b/0x30
[ 508.900754] __x64_sys_delete_module+0x16/0x20
[ 508.900758] x64_sys_call+0xdf/0x20d0
[ 508.900763] do_syscall_64+0x51/0x120
[ 508.900769] entry_SYSCALL_64_after_hwframe+0x76/0x7e
v2: call dma_fence_put in amdgpu_gem_va_update_vm
v3: Addressed review comments from Christian.
- calling amdgpu_gem_update_timeline_node before switch.
- puting a dma_fence in case of error or !timeline_syncobj.
Cc: Alex Deucher <alexander.deucher@xxxxxxx>
Cc: Christian König <christian.koenig@xxxxxxx>
Cc: Shashank Sharma <shashank.sharma@xxxxxxx>
Cc: Sunil Khatri <sunil.khatri@xxxxxxx>
Signed-off-by: Le Ma <le.ma@xxxxxxx>
Signed-off-by: Arvind Yadav <arvind.yadav@xxxxxxx>
---
drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c | 33 +++++++++++++------------
1 file changed, 17 insertions(+), 16 deletions(-)
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c
index 8b67aae6c2fe..40522b4f331b 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c
@@ -125,9 +125,6 @@ amdgpu_gem_update_bo_mapping(struct drm_file *filp,
struct amdgpu_vm *vm = &fpriv->vm;
struct dma_fence *last_update;
- if (!syncobj)
- return;
-
/* Find the last update fence */
switch (operation) {
case AMDGPU_VA_OP_MAP:
@@ -839,6 +836,7 @@ int amdgpu_gem_va_ioctl(struct drm_device *dev, void *data,
struct drm_exec exec;
uint64_t va_flags;
uint64_t vm_size;
+ int syncobj_status;
int r = 0;
if (args->va_address < AMDGPU_VA_RESERVED_BOTTOM) {
@@ -931,6 +929,12 @@ int amdgpu_gem_va_ioctl(struct drm_device *dev, void *data,
bo_va = NULL;
}
+ syncobj_status = amdgpu_gem_update_timeline_node(filp,
+ args->vm_timeline_syncobj_out,
+ args->vm_timeline_point,
+ &timeline_syncobj,
+ &timeline_chain);
+
You don't need syncobj_status here, just assign the return value to r and abort if we can't find any syncobj.
I have not used variable 'r' because below inside
switch(args->operation) the 'r' value will be reinitialized and the
return value of amdgpu_gem_update_timeline_node will not be used. Here,
we cannot abort because syncobj will be NULL for Non-UQ.
we can use r but it will not do anything. :)
switch (args->operation) {
case AMDGPU_VA_OP_MAP:
va_flags = amdgpu_gem_va_map_flags(adev, args->flags);
@@ -957,22 +961,19 @@ int amdgpu_gem_va_ioctl(struct drm_device *dev, void *data,
break;
}
if (!r && !(args->flags & AMDGPU_VM_DELAY_UPDATE) && !adev->debug_vm) {
-
- r = amdgpu_gem_update_timeline_node(filp,
- args->vm_timeline_syncobj_out,
- args->vm_timeline_point,
- &timeline_syncobj,
- &timeline_chain);
-
fence = amdgpu_gem_va_update_vm(adev, &fpriv->vm, bo_va,
args->operation);
- if (!r)
- amdgpu_gem_update_bo_mapping(filp, bo_va,
- args->operation,
- args->vm_timeline_point,
- fence, timeline_syncobj,
- timeline_chain);
+ if (syncobj_status || !timeline_syncobj) {
+ dma_fence_put(fence);
+ goto error;
+ }
That should probably be something like this:
if (timeline_syncobj)
amdgpu_gem_update_bo_mapping(..);
else
dma_fence_put(fence);
Noted....
Thanks,
Arvind
Regards,
Christian.
+
+ amdgpu_gem_update_bo_mapping(filp, bo_va,
+ args->operation,
+ args->vm_timeline_point,
+ fence, timeline_syncobj,
+ timeline_chain);
}
error:
