From 378b0ac17984edc1a040e3a084cb80af78075bda Mon Sep 17 00:00:00 2001 From: RitanyaB Date: Mon, 3 Jan 2022 11:22:50 -0600 Subject: [PATCH] SIGSEGV in ompt_tsan_dependences with for-ordered Segmentation fault in ompt_tsan_dependences function due to an unchecked NULL pointer dereference is as follows: ``` ThreadSanitizer:DEADLYSIGNAL ==140865==ERROR: ThreadSanitizer: SEGV on unknown address 0x000000000050 (pc 0x7f217c2d3652 bp 0x7ffe8cfc7e00 sp 0x7ffe8cfc7d90 T140865) ==140865==The signal is caused by a READ memory access. ==140865==Hint: address points to the zero page. /usr/bin/addr2line: DWARF error: could not find variable specification at offset 1012a /usr/bin/addr2line: DWARF error: could not find variable specification at offset 133b5 /usr/bin/addr2line: DWARF error: could not find variable specification at offset 1371a /usr/bin/addr2line: DWARF error: could not find variable specification at offset 13a58 #0 ompt_tsan_dependences(ompt_data_t*, ompt_dependence_t const*, int) /ptmp/bhararit/llvm-project/openmp/tools/archer/ompt-tsan.cpp:1004 (libarcher.so+0x15652) #1 __kmpc_doacross_post /ptmp/bhararit/llvm-project/openmp/runtime/src/kmp_csupport.cpp:4280 (libomp.so+0x74d98) #2 .omp_outlined. for_ordered_01.c:? (for_ordered_01.exe+0x5186cb) #3 __kmp_invoke_microtask /ptmp/bhararit/llvm-project/openmp/runtime/src/z_Linux_asm.S:1166 (libomp.so+0x14e592) #4 __kmp_invoke_task_func /ptmp/bhararit/llvm-project/openmp/runtime/src/kmp_runtime.cpp:7556 (libomp.so+0x909ad) #5 __kmp_fork_call /ptmp/bhararit/llvm-project/openmp/runtime/src/kmp_runtime.cpp:2284 (libomp.so+0x8461a) #6 __kmpc_fork_call /ptmp/bhararit/llvm-project/openmp/runtime/src/kmp_csupport.cpp:308 (libomp.so+0x6db55) #7 main ??:? (for_ordered_01.exe+0x51828f) #8 __libc_start_main ??:? (libc.so.6+0x24349) #9 _start /home/abuild/rpmbuild/BUILD/glibc-2.26/csu/../sysdeps/x86_64/start.S:120 (for_ordered_01.exe+0x4214e9) ThreadSanitizer can not provide additional info. SUMMARY: ThreadSanitizer: SEGV /ptmp/bhararit/llvm-project/openmp/tools/archer/ompt-tsan.cpp:1004 in ompt_tsan_dependences(ompt_data_t*, ompt_dependence_t const*, int) ==140865==ABORTING ``` To reproduce the error, use the following openmp code snippet: ``` /* initialise testMatrixInt Matrix, cols, r and c */ #pragma omp parallel private(r,c) shared(testMatrixInt) { #pragma omp for ordered(2) for (r=1; r < rows; r++) { for (c=1; c < cols; c++) { #pragma omp ordered depend(sink:r-1, c+1) depend(sink:r-1,c-1) testMatrixInt[r][c] = (testMatrixInt[r-1][c] + testMatrixInt[r-1][c-1]) % cols ; #pragma omp ordered depend (source) } } } ``` Compilation: ``` clang -g -stdlib=libc++ -fsanitize=thread -fopenmp -larcher test_case.c ``` It seems like the changes introduced by the commit https://reviews.llvm.org/D114005 causes this particular SEGV while using Archer. Reviewed By: protze.joachim Differential Revision: https://reviews.llvm.org/D115328 --- openmp/tools/archer/ompt-tsan.cpp | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/openmp/tools/archer/ompt-tsan.cpp b/openmp/tools/archer/ompt-tsan.cpp index bcd8417aa789..7e384ddfeaa1 100644 --- a/openmp/tools/archer/ompt-tsan.cpp +++ b/openmp/tools/archer/ompt-tsan.cpp @@ -1001,6 +1001,10 @@ static void ompt_tsan_dependences(ompt_data_t *task_data, if (ndeps > 0) { // Copy the data to use it in task_switch and task_end. TaskData *Data = ToTaskData(task_data); + if (!Data->Parent) { + // Return since doacross dependences are not supported yet. + return; + } if (!Data->Parent->DependencyMap) Data->Parent->DependencyMap = new std::unordered_map();