Add a test to prevent regressions. Signed-off-by: Ilya Leoshkevich <i...@linux.ibm.com> --- tests/tcg/multiarch/Makefile.target | 13 ++- .../gdbstub/test-thread-breakpoint-stress.py | 28 ++++++ .../tcg/multiarch/thread-breakpoint-stress.c | 92 +++++++++++++++++++ 3 files changed, 132 insertions(+), 1 deletion(-) create mode 100644 tests/tcg/multiarch/gdbstub/test-thread-breakpoint-stress.py create mode 100644 tests/tcg/multiarch/thread-breakpoint-stress.c
diff --git a/tests/tcg/multiarch/Makefile.target b/tests/tcg/multiarch/Makefile.target index 5e3391ec9d2..0a9cd037094 100644 --- a/tests/tcg/multiarch/Makefile.target +++ b/tests/tcg/multiarch/Makefile.target @@ -42,6 +42,9 @@ munmap-pthread: LDFLAGS+=-pthread vma-pthread: CFLAGS+=-pthread vma-pthread: LDFLAGS+=-pthread +thread-breakpoint-stress: CFLAGS+=-pthread +thread-breakpoint-stress: LDFLAGS+=-pthread + # The vma-pthread seems very sensitive on gitlab and we currently # don't know if its exposing a real bug or the test is flaky. ifneq ($(GITLAB_CI),) @@ -127,6 +130,13 @@ run-gdbstub-follow-fork-mode-parent: follow-fork-mode --bin $< --test $(MULTIARCH_SRC)/gdbstub/follow-fork-mode-parent.py, \ following parents on fork) +run-gdbstub-thread-breakpoint-stress: thread-breakpoint-stress + $(call run-test, $@, $(GDB_SCRIPT) \ + --gdb $(GDB) \ + --qemu $(QEMU) --qargs "$(QEMU_OPTS)" \ + --bin $< --test $(MULTIARCH_SRC)/gdbstub/test-thread-breakpoint-stress.py, \ + hitting many breakpoints on different threads) + else run-gdbstub-%: $(call skip-test, "gdbstub test $*", "need working gdb with $(patsubst -%,,$(TARGET_NAME)) support") @@ -136,7 +146,8 @@ EXTRA_RUNS += run-gdbstub-sha1 run-gdbstub-qxfer-auxv-read \ run-gdbstub-registers run-gdbstub-prot-none \ run-gdbstub-catch-syscalls run-gdbstub-follow-fork-mode-child \ run-gdbstub-follow-fork-mode-parent \ - run-gdbstub-qxfer-siginfo-read + run-gdbstub-qxfer-siginfo-read \ + run-gdbstub-thread-breakpoint-stress # ARM Compatible Semi Hosting Tests # diff --git a/tests/tcg/multiarch/gdbstub/test-thread-breakpoint-stress.py b/tests/tcg/multiarch/gdbstub/test-thread-breakpoint-stress.py new file mode 100644 index 00000000000..489d238f02d --- /dev/null +++ b/tests/tcg/multiarch/gdbstub/test-thread-breakpoint-stress.py @@ -0,0 +1,28 @@ +"""Test multiple threads hitting breakpoints. + +SPDX-License-Identifier: GPL-2.0-or-later +""" +from test_gdbstub import main, report + + +N_BREAK_THREADS = 2 +N_BREAKS = 100 + + +def run_test(): + """Run through the tests one by one""" + if gdb.selected_inferior().architecture().name() == "MicroBlaze": + print("SKIP: Atomics are broken on MicroBlaze") + exit(0) + gdb.execute("break break_here") + gdb.execute("continue") + for _ in range(N_BREAK_THREADS * N_BREAKS): + counter1 = int(gdb.parse_and_eval("s->counter")) + counter2 = int(gdb.parse_and_eval("s->counter")) + report(counter1 == counter2, "{} == {}".format(counter1, counter2)) + gdb.execute("continue") + exitcode = int(gdb.parse_and_eval("$_exitcode")) + report(exitcode == 0, "{} == 0".format(exitcode)) + + +main(run_test) diff --git a/tests/tcg/multiarch/thread-breakpoint-stress.c b/tests/tcg/multiarch/thread-breakpoint-stress.c new file mode 100644 index 00000000000..1feed8577aa --- /dev/null +++ b/tests/tcg/multiarch/thread-breakpoint-stress.c @@ -0,0 +1,92 @@ +/* + * Test multiple threads hitting breakpoints. + * + * The main thread performs a lengthy syscall. The test verifies that this + * does not interfere with the ability to stop threads. + * + * The counter thread constantly increments a value by 1. The test verifies + * that it is stopped when another thread hits a breakpoint. + * + * The break threads constantly and simultaneously hit the same breakpoint. + * The test verifies that GDB and gdbstub do not lose any hits and do not + * deadlock. + * + * SPDX-License-Identifier: GPL-2.0-or-later + */ +#include <assert.h> +#include <pthread.h> +#include <stdlib.h> + +struct state { + int counter; + int done; + pthread_barrier_t barrier; + int break_counter; +}; + +static void *counter_loop(void *arg) +{ + struct state *s = arg; + + while (!__atomic_load_n(&s->done, __ATOMIC_SEQ_CST)) { + __atomic_add_fetch(&s->counter, 1, __ATOMIC_SEQ_CST); + } + + return NULL; +} + +#define N_BREAK_THREADS 2 +#define N_BREAKS 100 + +/* Non-static to avoid inlining. */ +void break_here(struct state *s) +{ + __atomic_add_fetch(&s->break_counter, 1, __ATOMIC_SEQ_CST); +} + +static void *break_loop(void *arg) +{ + struct state *s = arg; + int i; + + pthread_barrier_wait(&s->barrier); + for (i = 0; i < N_BREAKS; i++) { + break_here(s); + } + + return NULL; +} + +int main(void) +{ + pthread_t break_threads[N_BREAK_THREADS], counter_thread; + struct state s = {}; + int i, ret; + +#ifdef __MICROBLAZE__ + /* + * Microblaze has broken atomics. + * See https://github.com/Xilinx/meta-xilinx/blob/xlnx-rel-v2024.1/meta-microblaze/recipes-devtools/gcc/gcc-12/0009-Patch-microblaze-Fix-atomic-boolean-return-value.patch + */ + return EXIT_SUCCESS; +#endif + + ret = pthread_barrier_init(&s.barrier, NULL, N_BREAK_THREADS); + assert(ret == 0); + ret = pthread_create(&counter_thread, NULL, counter_loop, &s); + assert(ret == 0); + for (i = 0; i < N_BREAK_THREADS; i++) { + ret = pthread_create(&break_threads[i], NULL, break_loop, &s); + assert(ret == 0); + } + for (i = 0; i < N_BREAK_THREADS; i++) { + ret = pthread_join(break_threads[i], NULL); + assert(ret == 0); + } + __atomic_store_n(&s.done, 1, __ATOMIC_SEQ_CST); + ret = pthread_join(counter_thread, NULL); + assert(ret == 0); + assert(s.break_counter == N_BREAK_THREADS * N_BREAKS); + + return EXIT_SUCCESS; +} -- 2.46.0