Latest OpenMP spec says parallel_data is NULL for initial/implicit-task-end.
We nevertheless need to cleanup the ParallelData here, as there is no other
callback for the end of the implicit parallel region. We can use the reference
stored in the TaskData.
Reviewed By: dreachem
Differential Revision: https://reviews.llvm.org/D114005
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
gcc 11 introduced support for depend clause, but the gomp interface of libomp
does not yet handle the information.
Also remove -fopenmp-version=50, which is no longer needed for clang, but not
supported by gcc.
The current handling of dependencies in Archer has two flaws:
- annotation of dependency synchronization is not limited to sibling tasks
- annotation of in/out dependencies is based on the assumption, that dependency
variables will rarely be byte-sized variables.
This patch introduces a map in the generating task to manage the dependency
variables for the child tasks. The map is only accesses from the generating
task, so no locking is necessary. This also limits the dependency-based
synchronization to sibling tasks.
This patch also introduces proper handling for new dependency types such as
mutexinoutset and inoutset.
Differential Revision: https://reviews.llvm.org/D103608
The main motivation for reusing objects is that it helps to avoid creating and
leaking synchronization clocks in TSan. The reused object will reuse the
synchronization clock in TSan.
Before, new and delete operators were overloaded to get and return memory for
the object from/to the object pool.
This patch replaces the operator overloading with explicit static New/Delete
functions.
Objects for parallel regions and implicit tasks will always be recruited and
returned to the thread-local object pool. Only for explicit task, there is a
chance that an other thread completes the task and will free the object. This
patch optimizes the thread-local New/Delete calls by avoiding locks and only
lock if the pool is empty. Remote threads return the object into a separate
queue.
The chunk size for allocations is now decided based on page size. The objects
will also be aligned to cache lines avoiding false sharing.
This is the first patch in a series to provide better tasking support.
Differential Revision: https://reviews.llvm.org/D103606
Archer uses weak symbol overloads of TSan functions to enable loading the tool
even if the application is not built with TSan. For MACOS the tool collects
the function pointer at runtime.
When adding the function entry/exit markers, we missed to add the functions
in the MACOS codepath.
This patch also replaces the repeated function lookup by a single initial
function lookup and fixes the disabling logic in RunningOnValgrind.
Differential Revision: https://reviews.llvm.org/D103607
OpenMP 5.1 introduces the new env variable
OMP_TOOL_VERBOSE_INIT=(disabled|stdout|stderr|<filename>) to enable verbose
loading and initialization of OMPT tools.
This env variable helps to understand the cause when loading of a tool fails
(e.g., undefined symbols or dependency not in LD_LIBRARY_PATH)
Output of OMP_TOOL_VERBOSE_INIT is added for OMP_DISPLAY_ENV
Tests for this patch are integrated into the different existing tool loading
tests, making these tests more verbose. An Archer specific verbose test is
integrated into an existing Archer test.
Patch prepared by: Isabel Thärigen
Differential Revision: https://reviews.llvm.org/D91464
This introduces the new `ARCHER_OPTIONS` flag `ignore_serial=0|1` to disable
analysis and logging of memory accesses in the sequential part of the OpenMP
application.
In the sequential part of an OpenMP program no data race is possible, unless
there is non-OpenMP concurrency (such as pthreads, MPI, ...). For the latter
reason, this is not active by default.
Besides reducing the runtime overhead for the sequential part of the program,
this reduces the memory overhead for sequential initialization. In combination
with `flush_shadow=1` this can allow analysis of applications, which run close
to the limit of available memory, but only access smaller parts of shared
memory during each OpenMP parallel region.
A problem for this approach is that Archer only gets active, when the OpenMP
runtime gets initialized, which might be after serial initialization of the
application. In such case, it helps to call for example `omp_get_max_threads()`
at the beginning of main.
Differential Revision: https://reviews.llvm.org/D90473
OpenMP 5.1 adds an extra enum entry for ompt_scope_t, which makes the related
switch statement incomplete.
Also adding cases for newly added barrier variants.
Differential Revision: https://reviews.llvm.org/D90758
Since detached tasks are supported by clang and the OpenMP runtime, Archer
must expect to receive the corresponding callbacks.
This patch adds support to interpret the synchronization semantics of
omp_fulfill_event and cleans up the handling of task switches.
The test disables suppression and therefore sometimes triggers a know false
positive in the openmp runtime. The test should only verify that the env
var is handles as expected.
Currently, the parser used to tokenize the TSAN_OPTIONS in libomp uses
only spaces as separators, even though TSAN in compiler-rt supports
other separators like ':' or ','.
CTest uses ':' to separate sanitizer options by default.
The documentation for other sanitizers mentions ':' as separator,
but TSAN only lists spaces, which is probably where this mismatch originated.
Patch provided by upsj
Differential Revision: https://reviews.llvm.org/D87144
Summary:
`config.test_extra_flags` is passed in from `lit.site.cfg.in` files, but they're not used in the LIT configs. This variable can be useful for distros which don't have the standard c/c++ headers in the default search paths. Since the tests run clang on c/c++ source code, we rely on `test_extra_flags` to pass in the necessary header files.
This is a similar setup that's also done in litomptarget https://github.com/llvm/llvm-project/blob/master/openmp/libomptarget/test/lit.cfg#L42 and openmp/runtime.
Reviewers: jdoerfert, jdenny, protze.joachim
Reviewed By: jdoerfert
Subscribers: yaxunl, guansong, sstefan1, openmp-commits
Tags: #openmp
Differential Revision: https://reviews.llvm.org/D82516
D78566 introduced a `\bnot\b` lit substitution in OpenMP test suites.
However, that would corrupt a command like
`FileCheck -implicit-check-not` or any file name like `%t.not`. We
could use lookbehind/lookahead assertions to avoid such cases, but
this patch switches to `%not` (suggested during the D78566 review) as
a safer option.
Reviewed By: jdoerfert
Differential Revision: https://reviews.llvm.org/D79529
Without this patch, the openmp project's test suites do not appear to
have support for negative tests. However, D78170 needs to add a test
that an expected runtime failure occurs.
This patch makes `not` visible in all of the openmp project's test
suites. In all but `libomptarget/test`, it should be possible for a
test author to insert `not` before a use of the lit substitution for
running a test program. In `libomptarget/test`, that substitution is
target-specific, and its value is `echo` when the target is not
available. In that case, inserting `not` before a lit substitution
would expect an `echo` fail, so this patch instead defines a separate
lit substitution for expected runtime fails.
Reviewed By: jdoerfert, Hahnfeld
Differential Revision: https://reviews.llvm.org/D78566
TSan spuriously reports for any OpenMP application a race on the initialization
of a runtime internal mutex:
```
Atomic read of size 1 at 0x7b6800005940 by thread T4:
#0 pthread_mutex_lock <null> (a.out+0x43f39e)
#1 __kmp_resume_64 <null> (libomp.so.5+0x84db4)
Previous write of size 1 at 0x7b6800005940 by thread T7:
#0 pthread_mutex_init <null> (a.out+0x424793)
#1 __kmp_suspend_initialize_thread <null> (libomp.so.5+0x8422e)
```
According to @AndreyChurbanov this is a false positive report, as the control
flow of the runtime guarantees the ordering of the mutex initialization and
the lock:
https://software.intel.com/en-us/forums/intel-open-source-openmp-runtime-library/topic/530363
To suppress this report, I suggest the use of
TSAN_OPTIONS='ignore_uninstrumented_modules=1'.
With this patch, a runtime warning is provided in case an OpenMP application
is built with Tsan and executed without this Tsan-option.
Reviewed By: jdoerfert
Differential Revision: https://reviews.llvm.org/D70412
The OpenMP runtime is not instrumented, so entering the runtime leaves no hint
on the source line of the pragma on ThreadSanitizer's function stack.
This patch adds function entry/exit annotations for OpenMP parallel regions,
and synchronization regions (barrier, taskwait, taskgroup).
Reviewed By: jdoerfert
Differential Revision: https://reviews.llvm.org/D70408
If the openmp project is built standalone, the test compiler is feature tested for an available -fsanitize=thread flag.
If the openmp project is built as part of llvm, the target tsan is needed to test archer.
An additional line (requires tsan) was introduced to the tests, this patch updates the line numbers for the race.
Follow-up for 77ad98c
Reviewed By: jdoerfert
Differential Revision: https://reviews.llvm.org/D71914
The tool provides TSAN annotations for OpenMP synchronization. The tool
is activated if no other OMPT tool is loaded.
The tool detects whether the application was built with TSan and rejects
activation according to the OMPT protocol if there is no TSan-rt.
Differential Revision: https://reviews.llvm.org/D45890
Joachim Protze