On 4/27/2018 11:54 AM, Robin Murphy wrote:
>
>> ubuntu at ubuntu:~/amdgpu$_./vectoradd_hip.exe
>> [Â 834.002206] create_process:620
>> [Â 837.413021] Unable to handle kernel NULL pointer dereference at virtual address 00000018
>
> £5 says that's sg_dma_len(NULL), which implies either that something's gone horribly wrong with the scatterlist DMA mapping such that the lengths don't match, or much more likely that ttm.dma_address is NULL and I've missed the tiny subtlety below. Does that fix matters?
Turned out to be a null pointer problem after sg_next(). The following helped.
+ if (addrs && (dma_len == 0)) {
dma_sg = sg_next(dma_sg);
- dma_len = sg_dma_len(dma_sg);
- addr = sg_dma_address(dma_sg);
+ if (dma_sg) {
+ dma_len = sg_dma_len(dma_sg);
+ addr = sg_dma_address(dma_sg);
+ }
}
--
Sinan Kaya
Qualcomm Datacenter Technologies, Inc. as an affiliate of Qualcomm Technologies, Inc.
Qualcomm Technologies, Inc. is a member of the Code Aurora Forum, a Linux Foundation Collaborative Project.
