[PATCH v3 21/23] selftests/rseq: parametrized vm_vcpu_id test

From: Mathieu Desnoyers
Date: Fri Jul 29 2022 - 15:04:31 EST

Adapt to the rseq.h API changes introduced by commits
"selftests/rseq: <arch>: Template memory ordering and percpu access mode".

Build a new param_test_vm_vcpu_id, param_test_vm_vcpu_id_benchmark, and
param_test_vm_vcpu_id_compare_twice executables to test the new
"vm_vcpu_id" rseq field.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@xxxxxxxxxxxx>
---
tools/testing/selftests/rseq/.gitignore | 3 +
tools/testing/selftests/rseq/Makefile | 15 +-
tools/testing/selftests/rseq/param_test.c | 148 ++++++++++++------
.../testing/selftests/rseq/run_param_test.sh | 5 +
4 files changed, 122 insertions(+), 49 deletions(-)

diff --git a/tools/testing/selftests/rseq/.gitignore b/tools/testing/selftests/rseq/.gitignore
index 5a7e5acc628c..db5c1a124c6c 100644
--- a/tools/testing/selftests/rseq/.gitignore
+++ b/tools/testing/selftests/rseq/.gitignore
@@ -6,3 +6,6 @@ basic_rseq_op_test
param_test
param_test_benchmark
param_test_compare_twice
+param_test_vm_vcpu_id
+param_test_vm_vcpu_id_benchmark
+param_test_vm_vcpu_id_compare_twice
diff --git a/tools/testing/selftests/rseq/Makefile b/tools/testing/selftests/rseq/Makefile
index 4210c135e621..3eec8e166385 100644
--- a/tools/testing/selftests/rseq/Makefile
+++ b/tools/testing/selftests/rseq/Makefile
@@ -13,7 +13,8 @@ LDLIBS += -lpthread -ldl
OVERRIDE_TARGETS = 1

TEST_GEN_PROGS = basic_test basic_percpu_ops_test basic_percpu_ops_vm_vcpu_id_test param_test \
- param_test_benchmark param_test_compare_twice
+ param_test_benchmark param_test_compare_twice param_test_vm_vcpu_id \
+ param_test_vm_vcpu_id_benchmark param_test_vm_vcpu_id_compare_twice

TEST_GEN_PROGS_EXTENDED = librseq.so

@@ -39,3 +40,15 @@ $(OUTPUT)/param_test_benchmark: param_test.c $(TEST_GEN_PROGS_EXTENDED) \
$(OUTPUT)/param_test_compare_twice: param_test.c $(TEST_GEN_PROGS_EXTENDED) \
rseq.h rseq-*.h
$(CC) $(CFLAGS) -DRSEQ_COMPARE_TWICE $< $(LDLIBS) -lrseq -o $@
+
+$(OUTPUT)/param_test_vm_vcpu_id: param_test.c $(TEST_GEN_PROGS_EXTENDED) \
+ rseq.h rseq-*.h
+ $(CC) $(CFLAGS) -DBUILDOPT_RSEQ_PERCPU_VM_VCPU_ID $< $(LDLIBS) -lrseq -o $@
+
+$(OUTPUT)/param_test_vm_vcpu_id_benchmark: param_test.c $(TEST_GEN_PROGS_EXTENDED) \
+ rseq.h rseq-*.h
+ $(CC) $(CFLAGS) -DBUILDOPT_RSEQ_PERCPU_VM_VCPU_ID -DBENCHMARK $< $(LDLIBS) -lrseq -o $@
+
+$(OUTPUT)/param_test_vm_vcpu_id_compare_twice: param_test.c $(TEST_GEN_PROGS_EXTENDED) \
+ rseq.h rseq-*.h
+ $(CC) $(CFLAGS) -DBUILDOPT_RSEQ_PERCPU_VM_VCPU_ID -DRSEQ_COMPARE_TWICE $< $(LDLIBS) -lrseq -o $@
diff --git a/tools/testing/selftests/rseq/param_test.c b/tools/testing/selftests/rseq/param_test.c
index 9869369a8607..f3687a90ec0c 100644
--- a/tools/testing/selftests/rseq/param_test.c
+++ b/tools/testing/selftests/rseq/param_test.c
@@ -16,6 +16,7 @@
#include <signal.h>
#include <errno.h>
#include <stddef.h>
+#include <stdbool.h>

static inline pid_t rseq_gettid(void)
{
@@ -36,7 +37,7 @@ static int opt_modulo, verbose;

static int opt_yield, opt_signal, opt_sleep,
opt_disable_rseq, opt_threads = 200,
- opt_disable_mod = 0, opt_test = 's', opt_mb = 0;
+ opt_disable_mod = 0, opt_test = 's';

static long long opt_reps = 5000;

@@ -264,6 +265,63 @@ unsigned int yield_mod_cnt, nr_abort;

#include "rseq.h"

+static enum rseq_mo opt_mo = RSEQ_MO_RELAXED;
+
+#ifdef RSEQ_ARCH_HAS_OFFSET_DEREF_ADDV
+#define TEST_MEMBARRIER
+
+static int sys_membarrier(int cmd, int flags, int cpu_id)
+{
+ return syscall(__NR_membarrier, cmd, flags, cpu_id);
+}
+#endif
+
+#ifdef BUILDOPT_RSEQ_PERCPU_VM_VCPU_ID
+# define RSEQ_PERCPU RSEQ_PERCPU_VM_VCPU_ID
+static
+int get_current_cpu_id(void)
+{
+ return rseq_current_vm_vcpu_id();
+}
+static
+bool rseq_validate_cpu_id(void)
+{
+ return rseq_vm_vcpu_id_available();
+}
+# ifdef TEST_MEMBARRIER
+/*
+ * Membarrier does not currently support targeting a vm_vcpu_id, so
+ * issue the barrier on all cpus.
+ */
+static
+int rseq_membarrier_expedited(int cpu)
+{
+ return sys_membarrier(MEMBARRIER_CMD_PRIVATE_EXPEDITED_RSEQ,
+ 0, 0);
+}
+# endif /* TEST_MEMBARRIER */
+#else
+# define RSEQ_PERCPU RSEQ_PERCPU_CPU_ID
+static
+int get_current_cpu_id(void)
+{
+ return rseq_cpu_start();
+}
+static
+bool rseq_validate_cpu_id(void)
+{
+ return rseq_current_cpu_raw() >= 0;
+}
+# ifdef TEST_MEMBARRIER
+static
+int rseq_membarrier_expedited(int cpu)
+{
+ return sys_membarrier(MEMBARRIER_CMD_PRIVATE_EXPEDITED_RSEQ,
+ MEMBARRIER_CMD_FLAG_CPU, cpu);
+}
+# endif /* TEST_MEMBARRIER */
+#endif
+
struct percpu_lock_entry {
intptr_t v;
} __attribute__((aligned(128)));
@@ -351,8 +409,9 @@ static int rseq_this_cpu_lock(struct percpu_lock *lock)
for (;;) {
int ret;

- cpu = rseq_cpu_start();
- ret = rseq_cmpeqv_storev(&lock->c[cpu].v,
+ cpu = get_current_cpu_id();
+ ret = rseq_cmpeqv_storev(RSEQ_MO_RELAXED, RSEQ_PERCPU,
+ &lock->c[cpu].v,
0, 1, cpu);
if (rseq_likely(!ret))
break;
@@ -469,8 +528,9 @@ void *test_percpu_inc_thread(void *arg)
do {
int cpu;

- cpu = rseq_cpu_start();
- ret = rseq_addv(&data->c[cpu].count, 1, cpu);
+ cpu = get_current_cpu_id();
+ ret = rseq_addv(RSEQ_MO_RELAXED, RSEQ_PERCPU,
+ &data->c[cpu].count, 1, cpu);
} while (rseq_unlikely(ret));
#ifndef BENCHMARK
if (i != 0 && !(i % (reps / 10)))
@@ -539,13 +599,14 @@ void this_cpu_list_push(struct percpu_list *list,
intptr_t *targetptr, newval, expect;
int ret;

- cpu = rseq_cpu_start();
+ cpu = get_current_cpu_id();
/* Load list->c[cpu].head with single-copy atomicity. */
expect = (intptr_t)RSEQ_READ_ONCE(list->c[cpu].head);
newval = (intptr_t)node;
targetptr = (intptr_t *)&list->c[cpu].head;
node->next = (struct percpu_list_node *)expect;
- ret = rseq_cmpeqv_storev(targetptr, expect, newval, cpu);
+ ret = rseq_cmpeqv_storev(RSEQ_MO_RELAXED, RSEQ_PERCPU,
+ targetptr, expect, newval, cpu);
if (rseq_likely(!ret))
break;
/* Retry if comparison fails or rseq aborts. */
@@ -571,13 +632,14 @@ struct percpu_list_node *this_cpu_list_pop(struct percpu_list *list,
long offset;
int ret;

- cpu = rseq_cpu_start();
+ cpu = get_current_cpu_id();
targetptr = (intptr_t *)&list->c[cpu].head;
expectnot = (intptr_t)NULL;
offset = offsetof(struct percpu_list_node, next);
load = (intptr_t *)&head;
- ret = rseq_cmpnev_storeoffp_load(targetptr, expectnot,
- offset, load, cpu);
+ ret = rseq_cmpnev_storeoffp_load(RSEQ_MO_RELAXED, RSEQ_PERCPU,
+ targetptr, expectnot,
+ offset, load, cpu);
if (rseq_likely(!ret)) {
node = head;
break;
@@ -715,7 +777,7 @@ bool this_cpu_buffer_push(struct percpu_buffer *buffer,
intptr_t offset;
int ret;

- cpu = rseq_cpu_start();
+ cpu = get_current_cpu_id();
offset = RSEQ_READ_ONCE(buffer->c[cpu].offset);
if (offset == buffer->c[cpu].buflen)
break;
@@ -723,14 +785,9 @@ bool this_cpu_buffer_push(struct percpu_buffer *buffer,
targetptr_spec = (intptr_t *)&buffer->c[cpu].array[offset];
newval_final = offset + 1;
targetptr_final = &buffer->c[cpu].offset;
- if (opt_mb)
- ret = rseq_cmpeqv_trystorev_storev_release(
- targetptr_final, offset, targetptr_spec,
- newval_spec, newval_final, cpu);
- else
- ret = rseq_cmpeqv_trystorev_storev(targetptr_final,
- offset, targetptr_spec, newval_spec,
- newval_final, cpu);
+ ret = rseq_cmpeqv_trystorev_storev(opt_mo, RSEQ_PERCPU,
+ targetptr_final, offset, targetptr_spec,
+ newval_spec, newval_final, cpu);
if (rseq_likely(!ret)) {
result = true;
break;
@@ -753,7 +810,7 @@ struct percpu_buffer_node *this_cpu_buffer_pop(struct percpu_buffer *buffer,
intptr_t offset;
int ret;

- cpu = rseq_cpu_start();
+ cpu = get_current_cpu_id();
/* Load offset with single-copy atomicity. */
offset = RSEQ_READ_ONCE(buffer->c[cpu].offset);
if (offset == 0) {
@@ -763,7 +820,8 @@ struct percpu_buffer_node *this_cpu_buffer_pop(struct percpu_buffer *buffer,
head = RSEQ_READ_ONCE(buffer->c[cpu].array[offset - 1]);
newval = offset - 1;
targetptr = (intptr_t *)&buffer->c[cpu].offset;
- ret = rseq_cmpeqv_cmpeqv_storev(targetptr, offset,
+ ret = rseq_cmpeqv_cmpeqv_storev(RSEQ_MO_RELAXED, RSEQ_PERCPU,
+ targetptr, offset,
(intptr_t *)&buffer->c[cpu].array[offset - 1],
(intptr_t)head, newval, cpu);
if (rseq_likely(!ret))
@@ -920,7 +978,7 @@ bool this_cpu_memcpy_buffer_push(struct percpu_memcpy_buffer *buffer,
size_t copylen;
int ret;

- cpu = rseq_cpu_start();
+ cpu = get_current_cpu_id();
/* Load offset with single-copy atomicity. */
offset = RSEQ_READ_ONCE(buffer->c[cpu].offset);
if (offset == buffer->c[cpu].buflen)
@@ -931,15 +989,11 @@ bool this_cpu_memcpy_buffer_push(struct percpu_memcpy_buffer *buffer,
copylen = sizeof(item);
newval_final = offset + 1;
targetptr_final = &buffer->c[cpu].offset;
- if (opt_mb)
- ret = rseq_cmpeqv_trymemcpy_storev_release(
- targetptr_final, offset,
- destptr, srcptr, copylen,
- newval_final, cpu);
- else
- ret = rseq_cmpeqv_trymemcpy_storev(targetptr_final,
- offset, destptr, srcptr, copylen,
- newval_final, cpu);
+ ret = rseq_cmpeqv_trymemcpy_storev(
+ opt_mo, RSEQ_PERCPU,
+ targetptr_final, offset,
+ destptr, srcptr, copylen,
+ newval_final, cpu);
if (rseq_likely(!ret)) {
result = true;
break;
@@ -964,7 +1018,7 @@ bool this_cpu_memcpy_buffer_pop(struct percpu_memcpy_buffer *buffer,
size_t copylen;
int ret;

- cpu = rseq_cpu_start();
+ cpu = get_current_cpu_id();
/* Load offset with single-copy atomicity. */
offset = RSEQ_READ_ONCE(buffer->c[cpu].offset);
if (offset == 0)
@@ -975,8 +1029,8 @@ bool this_cpu_memcpy_buffer_pop(struct percpu_memcpy_buffer *buffer,
copylen = sizeof(*item);
newval_final = offset - 1;
targetptr_final = &buffer->c[cpu].offset;
- ret = rseq_cmpeqv_trymemcpy_storev(targetptr_final,
- offset, destptr, srcptr, copylen,
+ ret = rseq_cmpeqv_trymemcpy_storev(RSEQ_MO_RELAXED, RSEQ_PERCPU,
+ targetptr_final, offset, destptr, srcptr, copylen,
newval_final, cpu);
if (rseq_likely(!ret)) {
result = true;
@@ -1151,7 +1205,7 @@ static int set_signal_handler(void)
}

/* Test MEMBARRIER_CMD_PRIVATE_RESTART_RSEQ_ON_CPU membarrier command. */
-#ifdef RSEQ_ARCH_HAS_OFFSET_DEREF_ADDV
+#ifdef TEST_MEMBARRIER
struct test_membarrier_thread_args {
int stop;
intptr_t percpu_list_ptr;
@@ -1178,9 +1232,10 @@ void *test_membarrier_worker_thread(void *arg)
int ret;

do {
- int cpu = rseq_cpu_start();
+ int cpu = get_current_cpu_id();

- ret = rseq_offset_deref_addv(&args->percpu_list_ptr,
+ ret = rseq_offset_deref_addv(RSEQ_MO_RELAXED, RSEQ_PERCPU,
+ &args->percpu_list_ptr,
sizeof(struct percpu_list_entry) * cpu, 1, cpu);
} while (rseq_unlikely(ret));
}
@@ -1217,11 +1272,6 @@ void test_membarrier_free_percpu_list(struct percpu_list *list)
free(list->c[i].head);
}

-static int sys_membarrier(int cmd, int flags, int cpu_id)
-{
- return syscall(__NR_membarrier, cmd, flags, cpu_id);
-}
-
/*
* The manager thread swaps per-cpu lists that worker threads see,
* and validates that there are no unexpected modifications.
@@ -1260,8 +1310,7 @@ void *test_membarrier_manager_thread(void *arg)

/* Make list_b "active". */
atomic_store(&args->percpu_list_ptr, (intptr_t)&list_b);
- if (sys_membarrier(MEMBARRIER_CMD_PRIVATE_EXPEDITED_RSEQ,
- MEMBARRIER_CMD_FLAG_CPU, cpu_a) &&
+ if (rseq_membarrier_expedited(cpu_a) &&
errno != ENXIO /* missing CPU */) {
perror("sys_membarrier");
abort();
@@ -1284,8 +1333,7 @@ void *test_membarrier_manager_thread(void *arg)

/* Make list_a "active". */
atomic_store(&args->percpu_list_ptr, (intptr_t)&list_a);
- if (sys_membarrier(MEMBARRIER_CMD_PRIVATE_EXPEDITED_RSEQ,
- MEMBARRIER_CMD_FLAG_CPU, cpu_b) &&
+ if (rseq_membarrier_expedited(cpu_b) &&
errno != ENXIO /* missing CPU*/) {
perror("sys_membarrier");
abort();
@@ -1356,7 +1404,7 @@ void test_membarrier(void)
abort();
}
}
-#else /* RSEQ_ARCH_HAS_OFFSET_DEREF_ADDV */
+#else /* TEST_MEMBARRIER */
void test_membarrier(void)
{
fprintf(stderr, "rseq_offset_deref_addv is not implemented on this architecture. "
@@ -1513,7 +1561,7 @@ int main(int argc, char **argv)
verbose = 1;
break;
case 'M':
- opt_mb = 1;
+ opt_mo = RSEQ_MO_RELEASE;
break;
default:
show_usage(argc, argv);
@@ -1533,6 +1581,10 @@ int main(int argc, char **argv)

if (!opt_disable_rseq && rseq_register_current_thread())
goto error;
+ if (!opt_disable_rseq && !rseq_validate_cpu_id()) {
+ fprintf(stderr, "Error: cpu id getter unavailable\n");
+ goto error;
+ }
switch (opt_test) {
case 's':
printf_verbose("spinlock\n");
diff --git a/tools/testing/selftests/rseq/run_param_test.sh b/tools/testing/selftests/rseq/run_param_test.sh
index f51bc83c9e41..11b5424e8b78 100755
--- a/tools/testing/selftests/rseq/run_param_test.sh
+++ b/tools/testing/selftests/rseq/run_param_test.sh
@@ -42,6 +42,11 @@ function do_tests()
./param_test ${TEST_LIST[$i]} -r ${REPS} -t ${NR_THREADS} ${@} ${EXTRA_ARGS} || exit 1
echo "Running compare-twice test ${TEST_NAME[$i]}"
./param_test_compare_twice ${TEST_LIST[$i]} -r ${REPS} -t ${NR_THREADS} ${@} ${EXTRA_ARGS} || exit 1
+
+ echo "Running vm vcpu_id test ${TEST_NAME[$i]}"
+ ./param_test_vm_vcpu_id ${TEST_LIST[$i]} -r ${REPS} -t ${NR_THREADS} ${@} ${EXTRA_ARGS} || exit 1
+ echo "Running vm vcpu_id compare-twice test ${TEST_NAME[$i]}"
+ ./param_test_vm_vcpu_id_compare_twice ${TEST_LIST[$i]} -r ${REPS} -t ${NR_THREADS} ${@} ${EXTRA_ARGS} || exit 1
let "i++"
done
}
--
2.17.1