|Summary:||graphics/mesa-dri: Segmentation fault occurs while executing atexit handlers (affects lang/clover: Segmentation fault in OpenCL programs)|
|Product:||Ports & Packages||Reporter:||shamaz.mazum|
|Component:||Individual Port(s)||Assignee:||freebsd-x11 (Nobody) <x11>|
|Severity:||Affects Some People||CC:||dumbbell, greg, jbeich|
Description shamaz.mazum 2019-09-23 07:26:26 UTC
Created attachment 207731 [details] Constructor/destructor workaround Hello. This is a long standing bug (at least for me), but I've decided to report only now. When you use an OpenCL program using lang/clover, the programm will crash at exit. I've tracked the problem to a file src/util/u_queue.c in mesa sources. The segmentation fault occurs while executing atexit handlers (one such hander is added in global_init() ). BTW, there is nothing wrong with atexit_handler() function itself: it can be empty and the result will be the same (segmentation fault). I tried to reproduce this behavior in a test program without success, so I have no idea what is causing the bug. Meanwhile, I wrote a little workarond using constructor and destructor functions (supported by both clang and gcc). This works just fine without any errors.
Comment 1 Kubilay Kocak 2019-09-23 08:02:22 UTC
Thank you for the report and patch. You mention "the program will crash at exit", could you detail what programs crashes? Are they programs from ports/packages? Are they custom programs you're unable to provide additional information, or core's/backtraces for? It may well also be worth reporting this issue upstream, as they may have a much better chance of reproduction or isolation, particularly in debug/traces are unable to be provided
Comment 2 shamaz.mazum 2019-09-23 08:23:33 UTC
> could you detail what programs crashes? Are they programs from ports/packages? I mean ALL programs using clover ocl provider, including devel/clinfo. One important thing, I forgot to mention is that you must have a suitable GPU (AMD Radeon HD or RX series will do) and drm-kmod port installed or old radeonkms module loaded (latter works only for old HD cards). Try to launch clinfo and you will see something like this: Number of platforms 1 Platform Name Clover Platform Vendor Mesa Platform Version OpenCL 1.1 Mesa 18.3.2 Platform Profile FULL_PROFILE Platform Extensions cl_khr_icd Platform Extensions function suffix MESA Platform Name Clover Number of devices 1 Device Name Radeon RX 580 Series (POLARIS10, DRM 3.23.0, 12.0-RELEASE-p10, LLVM 8.0.1) Device Vendor AMD Device Vendor ID 0x1002 Device Version OpenCL 1.1 Mesa 18.3.2 Driver Version 18.3.2 Device OpenCL C Version OpenCL C 1.1 Device Type GPU Device Profile FULL_PROFILE Max compute units 36 Max clock frequency 1411MHz Max work item dimensions 3 Max work item sizes 256x256x256 Max work group size 256 Preferred work group size multiple 64 Preferred / native vector sizes char 16 / 16 short 8 / 8 int 4 / 4 long 2 / 2 half 8 / 8 (cl_khr_fp16) float 4 / 4 double 2 / 2 (cl_khr_fp64) Half-precision Floating-point support (cl_khr_fp16) Denormals No Infinity and NANs Yes Round to nearest Yes Round to zero No Round to infinity No IEEE754-2008 fused multiply-add No Support is emulated in software No Correctly-rounded divide and sqrt operations No Single-precision Floating-point support (core) Denormals No Infinity and NANs Yes Round to nearest Yes Round to zero No Round to infinity No IEEE754-2008 fused multiply-add No Support is emulated in software No Correctly-rounded divide and sqrt operations No Double-precision Floating-point support (cl_khr_fp64) Denormals Yes Infinity and NANs Yes Round to nearest Yes Round to zero Yes Round to infinity Yes IEEE754-2008 fused multiply-add Yes Support is emulated in software No Correctly-rounded divide and sqrt operations No Address bits 64, Little-Endian Global memory size 4294967296 (4GiB) Error Correction support No Max memory allocation 3435973836 (3.2GiB) Unified memory for Host and Device No Minimum alignment for any data type 128 bytes Alignment of base address 32768 bits (4096 bytes) Global Memory cache type None Image support No Local memory type Local Local memory size 32768 (32KiB) Max constant buffer size 2147483647 (2GiB) Max number of constant args 16 Max size of kernel argument 1024 Queue properties Out-of-order execution No Profiling Yes Profiling timer resolution 0ns Execution capabilities Run OpenCL kernels Yes Run native kernels No Device Available Yes Compiler Available Yes Device Extensions cl_khr_byte_addressable_store cl_khr_global_int32_base_atomics cl_khr_global_int32_extended_atomics cl_khr_local_int32_base_atomics cl_khr_local_int32_extended_atomics cl_khr_int64_base_atomics cl_khr_int64_extended_atomics cl_khr_fp64 cl_khr_fp16 NULL platform behavior clGetPlatformInfo(NULL, CL_PLATFORM_NAME, ...) Clover clGetDeviceIDs(NULL, CL_DEVICE_TYPE_ALL, ...) Success [MESA] clCreateContext(NULL, ...) [default] Success [MESA] clCreateContextFromType(NULL, CL_DEVICE_TYPE_CPU) No devices found in platform clCreateContextFromType(NULL, CL_DEVICE_TYPE_GPU) Success (1) Platform Name Clover Device Name Radeon RX 580 Series (POLARIS10, DRM 3.23.0, 12.0-RELEASE-p10, LLVM 8.0.1) clCreateContextFromType(NULL, CL_DEVICE_TYPE_ACCELERATOR) No devices found in platform clCreateContextFromType(NULL, CL_DEVICE_TYPE_CUSTOM) No devices found in platform clCreateContextFromType(NULL, CL_DEVICE_TYPE_ALL) Success (1) Platform Name Clover Device Name Radeon RX 580 Series (POLARIS10, DRM 3.23.0, 12.0-RELEASE-p10, LLVM 8.0.1) ICD loader properties ICD loader Name OpenCL ICD Loader ICD loader Vendor OCL Icd free software ICD loader Version 2.2.12 ICD loader Profile OpenCL 2.2 NOTE: your OpenCL library declares to support OpenCL 2.2, but it seems to support up to OpenCL 2.1 only. Ошибка сегментации(core dumped) I think maybe others FreeBSD+OpenCL+clover users may confirm this. My guess is that this is FreeBSD specific, because otherwise it would be noticed (maybe I am incorrect, but I think that there are not many OpenCL users who use FreeBSD).
Comment 3 Kubilay Kocak 2019-09-25 02:50:58 UTC
If you can obtain a backtrace of the crash (as an attachment), that might be handy
Comment 4 shamaz.mazum 2019-09-25 14:49:45 UTC
This is a backtrace (it's short, no need in attachment). (lldb) bt * thread #1, name = 'clinfo', stop reason = signal SIGSEGV * frame #0: 0x0000000806ce81d0 frame #1: 0x0000000800a030c5 libc.so.7`__cxa_finalize(dso=0x0000000000000000) at atexit.c:239 frame #2: 0x0000000800992cc1 libc.so.7`exit(status=0) at exit.c:74 frame #3: 0x0000000000401526 clinfo`___lldb_unnamed_symbol1$$clinfo + 390