On 05/25/2018 03:54 PM, Christian König wrote:
> Am 25.05.2018 um 09:20 schrieb Zhang, Jerry (Junwei):
>> On 05/25/2018 02:44 PM, Christian König wrote:
>>> NAK, that probably just fixed the symptom but not the underlying problem.
>>>
>>> Somebody is accessing the page array when it should never be accessed.
>>
>> If prime import as GTT bo by default(now it's CPU bo), it would happens
>> quickly when GTT sg bo creation rather than next cs validation.
>>
>> Since ttm_sg_tt_init() only allocates gtt->ttm.dma_address if sg bo is
>> created, it would fail to access ttm->pages when ttm populate.
>
> And exactly that's the problem, and imported BO should never populate.
>
>>
>> current error happens in ttm populate from cs validation, the sg bo is
>> imported from exporter.
>>
>>>
>>> How did you manage to trigger this?
>>
>> PRI_PRIME=1 with Unigine heaven.
>
> Going to give that a try, but the last time I check that worked as expected.
FYI.
PRI_PRIME=1 glxinfo will not trigger that, but the game does.
Jerry
>
> Thanks,
> Christian.
>
>>
>> Regards,
>> Jerry
>>
>>>
>>> Regards,
>>> Christian.
>>>
>>> Am 25.05.2018 um 07:41 schrieb Junwei Zhang:
>>>> [ 632.679861] BUG: unable to handle kernel NULL pointer dereference at (null)
>>>> [ 632.679892] IP: drm_prime_sg_to_page_addr_arrays+0x52/0xb0 [drm]
>>>> <snip>
>>>> [ 632.680011] Call Trace:
>>>> [ 632.680082] amdgpu_ttm_tt_populate+0x3e/0xa0 [amdgpu]
>>>> [ 632.680092] ttm_tt_populate.part.7+0x22/0x60 [amdttm]
>>>> [ 632.680098] amdttm_tt_bind+0x52/0x60 [amdttm]
>>>> [ 632.680106] ttm_bo_handle_move_mem+0x54b/0x5c0 [amdttm]
>>>> [ 632.680112] ? find_next_bit+0xb/0x10
>>>> [ 632.680119] amdttm_bo_validate+0x11d/0x130 [amdttm]
>>>> [ 632.680176] amdgpu_cs_bo_validate+0x9d/0x150 [amdgpu]
>>>> [ 632.680232] amdgpu_cs_validate+0x41/0x270 [amdgpu]
>>>> [ 632.680288] amdgpu_cs_list_validate+0xc7/0x1a0 [amdgpu]
>>>> [ 632.680343] amdgpu_cs_ioctl+0x1634/0x1c00 [amdgpu]
>>>> [ 632.680401] ? amdgpu_cs_find_mapping+0x120/0x120 [amdgpu]
>>>> [ 632.680416] drm_ioctl_kernel+0x6b/0xb0 [drm]
>>>> [ 632.680431] drm_ioctl+0x3e4/0x450 [drm]
>>>> [ 632.680485] ? amdgpu_cs_find_mapping+0x120/0x120 [amdgpu]
>>>> [ 632.680537] amdgpu_drm_ioctl+0x4c/0x80 [amdgpu]
>>>> [ 632.680542] do_vfs_ioctl+0xa4/0x600
>>>> [ 632.680546] ? SyS_futex+0x7f/0x180
>>>> [ 632.680549] SyS_ioctl+0x79/0x90
>>>> [ 632.680554] entry_SYSCALL_64_fastpath+0x24/0xab
>>>>
>>>> Signed-off-by: Junwei Zhang <Jerry.Zhang at amd.com>
>>>> ---
>>>> drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c | 2 +-
>>>> 1 file changed, 1 insertion(+), 1 deletion(-)
>>>>
>>>> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
>>>> b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
>>>> index 57d4da6..b293809 100644
>>>> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
>>>> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
>>>> @@ -1212,7 +1212,7 @@ static struct ttm_tt *amdgpu_ttm_tt_create(struct
>>>> ttm_buffer_object *bo,
>>>> gtt->ttm.ttm.func = &amdgpu_backend_func;
>>>> /* allocate space for the uninitialized page entries */
>>>> - if (ttm_sg_tt_init(>t->ttm, bo, page_flags)) {
>>>> + if (ttm_dma_tt_init(>t->ttm, bo, page_flags)) {
>>>> kfree(gtt);
>>>> return NULL;
>>>> }
>>>
>
