Bug 102233

Summary: OpenCL segmentation fault on AMD Radeon (Kaveri+R7) with memtestCL
Product: Mesa Reporter: Senad <senad.jahic>
Component: Drivers/Gallium/radeonsiAssignee: Default DRI bug account <dri-devel>
Status: RESOLVED NOTOURBUG QA Contact: Default DRI bug account <dri-devel>
Severity: critical    
Priority: medium    
Version: git   
Hardware: x86-64 (AMD64)   
OS: Linux (All)   
Whiteboard:
i915 platform: i915 features:
Bug Depends on:    
Bug Blocks: 99553    

Description Senad 2017-08-15 14:06:16 UTC 
Hardware:
AMD A8-7600 with Radeon™ R7 Series
Sapphire R7 240 4GB
ASUS R7 240 4GB

OS: Ubuntu server 17.04 64bit (headless mode).
OpenCL Driver: Padoka


Description:
clinfo works, shows all three GPU platforms.
Sometimes I get segmentation fault using memtestCL.
I get 100% crashes with YACMiner (crypto mining software).


I've traced memtestCL down to this line:
https://github.com/ihaque/memtestCL/blob/607499a54dcac9b846fcc827dc5980d8e5f66cec/memtestCL_cli.cpp#L126

On repeating runs, clGetDeviceIDs sometimes returns 0 for num_cpu and sometimes 1.
If it returns 1, clGetDeviceInfo later crashes when called with device id that does not exist.

If I hardcode "num_devices=3" at offending line, I can run memtestCL on all three devices successfully without faults.
Comment 1 Jan Vesely 2017-09-15 22:41:37 UTC 
What is the mesa/llvm version?
can you post clinfo?
do you use ocl-icd library? if so can you run setting
OCL_ICD_VENDORS=/etc/OpenCL/vendors/mesa.icd
Comment 2 Jan Vesely 2017-12-22 12:16:15 UTC 
Can you try initializing the num_gpu, num_cpu, num_accel variables?
clGetDeviceIDs returns CL_DEVICE_NOT_FOUND error if there are no devices matching the requested type. This does not set num_devices output parameter to 0.

Unless the variables are initialized to 0, the loop on line 135 accesses devids array out of bounds.
Comment 3 Jan Vesely 2017-12-22 12:17:45 UTC 
(In reply to Senad from comment #0)
> I get 100% crashes with YACMiner (crypto mining software).

please report a separate bug for YACMiner
Comment 4 Jan Vesely 2018-05-10 19:06:18 UTC 
This PR should fix memtestCL:
https://github.com/ihaque/memtestCL/pull/9

feel free to reopen if you still see the problem.

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