Undetected platform due to Clang address' sanitizer? - memory-leaks

Question

I use clang 14.0.5 and link against what is provided by ocl-icd-devel (v 2.3.1) on a fedora 36 box. I am running on a x86-64 CPU attached to a gtx1050ti and the nvidia-smi report is given below:
+-----------------------------------------------------------------------------+
| NVIDIA-SMI 525.85.05 Driver Version: 525.85.05 CUDA Version: 12.0 |
|-------------------------------+----------------------+----------------------+
| GPU Name Persistence-M| Bus-Id Disp.A | Volatile Uncorr. ECC |
| Fan Temp Perf Pwr:Usage/Cap| Memory-Usage | GPU-Util Compute M. |
| | | MIG M. |
|===============================+======================+======================|
| 0 NVIDIA GeForce ... Off | 00000000:01:00.0 Off | N/A |
| N/A 39C P8 N/A / N/A | 3MiB / 4096MiB | 0% Default |
| | | N/A |
+-------------------------------+----------------------+----------------------+
Assuming the code below:
#include <CL/cl.h>
#include <iostream>
int main() {
::cl_uint platform_count;
::clGetPlatformIDs(0, NULL, &platform_count);
std::cout << platform_count << "\n";
}
The clGetPlatformIDs function does not fail.
Compiled with clang++ test.cc -lOpenCL leads to the following output:
2
I indeed have two OpenCL platforms, Nvidia and Mesa, as properly reported by clinfo. This is the expected behavior.
Now, compiling with clang++ test.cc -lOpenCL -fsanitize=address leads to the following output:
1
=================================================================
==119688==ERROR: LeakSanitizer: detected memory leaks
Direct leak of 1120 byte(s) in 20 object(s) allocated from:
#0 0x4cfd97 in __interceptor_calloc (/../test+0x4cfd97) (BuildId: 66d5be805632cad14f58fab06c64ebed85d7da00)
#1 0x7f6d3ce7fad9 (/lib64/libnvidia-opencl.so.1+0x27fad9) (BuildId: ca94830f39da5d51a55258eb21cc484556b036b5)
Indirect leak of 1920 byte(s) in 20 object(s) allocated from:
#0 0x4cfd97 in __interceptor_calloc (/../test+0x4cfd97) (BuildId: 66d5be805632cad14f58fab06c64ebed85d7da00)
#1 0x7f6d3ce7faf4 (/lib64/libnvidia-opencl.so.1+0x27faf4) (BuildId: ca94830f39da5d51a55258eb21cc484556b036b5)
...
<cut for brievety>
This issue does not shows up if I target x86 (clang triple: i686--linux-), that is, I get two platforms. Though the sanitizer still catches potential memory leaks:
================================================================
==119438==ERROR: LeakSanitizer: detected memory leaks
Direct leak of 880 byte(s) in 20 object(s) allocated from:
#0 0x8120c0b in __interceptor_calloc (/../test+0x8120c0b) (BuildId: 9b9e395397d659c010914e0c90e5d710fc95826d)
#1 0xf36bea17 (/lib/libnvidia-opencl.so.1+0x2bea17) (BuildId: 9ea2f83814d7ff837ade8227643aea1f94ba6908)
#2 0xf36944c3 (/lib/libnvidia-opencl.so.1+0x2944c3) (BuildId: 9ea2f83814d7ff837ade8227643aea1f94ba6908)
#3 0xf36a07a9 (/lib/libnvidia-opencl.so.1+0x2a07a9) (BuildId: 9ea2f83814d7ff837ade8227643aea1f94ba6908)
#4 0xf351358c (/lib/libnvidia-opencl.so.1+0x11358c) (BuildId: 9ea2f83814d7ff837ade8227643aea1f94ba6908)
...
<cut for brievety>
The same code in C leads to:
#include <CL/cl.h>
#include <stdio.h>
int main() {
cl_uint platform_count;
if(CL_SUCCESS == clGetPlatformIDs(0, NULL, &platform_count))
printf("%d\n", platform_count);
}
Which also fails but in a different way:
AddressSanitizer: CHECK failed: asan_interceptors.cpp:321 "((__interception::real___cxa_throw)) != (0)" (0x0, 0x0) (tid=72340)
#0 0x4d7a5a in __asan::CheckUnwind() asan_rtl.cpp.o
#1 0x4f3a0d in __sanitizer::CheckFailed(char const*, int, char const*, unsigned long long, unsigned long long) (/.../test+0x4f3a0d) (BuildId: 957a08089740f3382763ab916b58469c68e1b465)
#2 0x444804 in __interceptor___cxa_throw (/.../test+0x444804) (BuildId: 957a08089740f3382763ab916b58469c68e1b465)
#3 0x7faa03669d28 (/lib64/libMesaOpenCL.so.1+0x30d28) (BuildId: 810b5bd27dbdbfd1325bb221f29c97960f5b6183)
#4 0x7faa036a3699 (/lib64/libMesaOpenCL.so.1+0x6a699) (BuildId: 810b5bd27dbdbfd1325bb221f29c97960f5b6183)
#5 0x7faa0366d77c (/lib64/libMesaOpenCL.so.1+0x3477c) (BuildId: 810b5bd27dbdbfd1325bb221f29c97960f5b6183)
#6 0x7faa05df1f7d in call_init /usr/src/debug/glibc-2.35-22.fc36.x86_64/elf/dl-init.c:70:3
#7 0x7faa05df1f7d in call_init /usr/src/debug/glibc-2.35-22.fc36.x86_64/elf/dl-init.c:26:1
#8 0x7faa05df206b in _dl_init /usr/src/debug/glibc-2.35-22.fc36.x86_64/elf/dl-init.c:117:5
#9 0x7faa05b54773 in _dl_catch_exception (/lib64/libc.so.6+0x154773) (BuildId: 8257ee907646e9b057197533d1e4ac8ede7a9c5c)
#10 0x7faa05df9195 in dl_open_worker /usr/src/debug/glibc-2.35-22.fc36.x86_64/elf/dl-open.c:808:5
#11 0x7faa05b5471d in _dl_catch_exception (/lib64/libc.so.6+0x15471d) (BuildId: 8257ee907646e9b057197533d1e4ac8ede7a9c5c)
#12 0x7faa05df952b in _dl_open /usr/src/debug/glibc-2.35-22.fc36.x86_64/elf/dl-open.c:884:17
#13 0x7faa05a88edb in dlopen_doit (/lib64/libc.so.6+0x88edb) (BuildId: 8257ee907646e9b057197533d1e4ac8ede7a9c5c)
#14 0x7faa05b5471d in _dl_catch_exception (/lib64/libc.so.6+0x15471d) (BuildId: 8257ee907646e9b057197533d1e4ac8ede7a9c5c)
#15 0x7faa05b547d2 in _dl_catch_error (/lib64/libc.so.6+0x1547d2) (BuildId: 8257ee907646e9b057197533d1e4ac8ede7a9c5c)
#16 0x7faa05a889ae in _dlerror_run (/lib64/libc.so.6+0x889ae) (BuildId: 8257ee907646e9b057197533d1e4ac8ede7a9c5c)
#17 0x7faa05a88f90 in dlopen##GLIBC_2.34 (/lib64/libc.so.6+0x88f90) (BuildId: 8257ee907646e9b057197533d1e4ac8ede7a9c5c)
#18 0x46c007 in __interceptor_dlopen.part.0 asan_interceptors.cpp.o
#19 0x7faa05dab8a5 (/lib64/libOpenCL.so.1+0xc8a5) (BuildId: 0ebfaaa96fdffe2b1aa490dea42c38ae14275426)
#20 0x7faa05daee70 (/lib64/libOpenCL.so.1+0xfe70) (BuildId: 0ebfaaa96fdffe2b1aa490dea42c38ae14275426)
#21 0x7faa05db0f73 in clGetPlatformIDs (/lib64/libOpenCL.so.1+0x11f73) (BuildId: 0ebfaaa96fdffe2b1aa490dea42c38ae14275426)
#22 0x511689 in main (/.../test+0x511689) (BuildId: 957a08089740f3382763ab916b58469c68e1b465)
#23 0x7faa05a2950f in __libc_start_call_main (/lib64/libc.so.6+0x2950f) (BuildId: 8257ee907646e9b057197533d1e4ac8ede7a9c5c)
#24 0x7faa05a295c8 in __libc_start_main#GLIBC_2.2.5 (/lib64/libc.so.6+0x295c8) (BuildId: 8257ee907646e9b057197533d1e4ac8ede7a9c5c)
#25 0x41c304 in _start (/.../test+0x41c304) (BuildId: 957a08089740f3382763ab916b58469c68e1b465)
Finally, if I use the undefined sanitizer, I do not get the platform count issue nor reported undefined behavior.