Re: [patch 10/10] selftests/rseq: Expand for optimized RSEQ ABI v2

On Wed, 29 Apr 2026 at 01:34, Thomas Gleixner <[email protected]> wrote:
>
> Update the selftests so they are executed for legacy (32 bytes RSEQ region)
> and optimized RSEQ ABI v2 mode.
>
> Fixes: d6200245c75e ("rseq: Allow registering RSEQ with slice extension")
> Signed-off-by: Thomas Gleixner <[email protected]>
> Cc: [email protected]

Reviewed-by: Dmitry Vyukov <[email protected]>

> ---
>  tools/testing/selftests/rseq/Makefile              |    7 ++-
>  tools/testing/selftests/rseq/check_optimized.c     |   17 +++++++++
>  tools/testing/selftests/rseq/param_test.c          |   22 +++++++----
>  tools/testing/selftests/rseq/run_param_test.sh     |   39 +++++++++++++++++++++
>  tools/testing/selftests/rseq/run_timeslice_test.sh |   14 +++++++
>  tools/testing/selftests/rseq/slice_test.c          |    2 -
>  6 files changed, 89 insertions(+), 12 deletions(-)
>
> --- a/tools/testing/selftests/rseq/Makefile
> +++ b/tools/testing/selftests/rseq/Makefile
> @@ -17,11 +17,11 @@ OVERRIDE_TARGETS = 1
>  TEST_GEN_PROGS = basic_test basic_percpu_ops_test basic_percpu_ops_mm_cid_test param_test \
>                 param_test_benchmark param_test_compare_twice param_test_mm_cid \
>                 param_test_mm_cid_benchmark param_test_mm_cid_compare_twice \
> -               syscall_errors_test slice_test legacy_check
> +               syscall_errors_test slice_test legacy_check check_optimized
>
>  TEST_GEN_PROGS_EXTENDED = librseq.so
>
> -TEST_PROGS = run_param_test.sh run_syscall_errors_test.sh run_legacy_check.sh
> +TEST_PROGS = run_param_test.sh run_syscall_errors_test.sh run_legacy_check.sh run_timeslice_test.sh
>
>  TEST_FILES := settings
>
> @@ -62,3 +62,6 @@ include ../lib.mk
>
>  $(OUTPUT)/slice_test: slice_test.c $(TEST_GEN_PROGS_EXTENDED) rseq.h rseq-*.h
>         $(CC) $(CFLAGS) $< $(LDLIBS) -lrseq -o $@
> +
> +$(OUTPUT)/check_optimized: check_optimized.c $(TEST_GEN_PROGS_EXTENDED) rseq.h rseq-*.h
> +       $(CC) $(CFLAGS) $< $(LDLIBS) -lrseq -o $@
> --- /dev/null
> +++ b/tools/testing/selftests/rseq/check_optimized.c
> @@ -0,0 +1,17 @@
> +// SPDX-License-Identifier: LGPL-2.1
> +#define _GNU_SOURCE
> +#include <assert.h>
> +#include <sched.h>
> +#include <signal.h>
> +#include <stdio.h>
> +#include <string.h>
> +#include <sys/time.h>
> +
> +#include "rseq.h"
> +
> +int main(int argc, char **argv)
> +{
> +       if (__rseq_register_current_thread(true, false))
> +               return -1;
> +       return 0;
> +}
> --- a/tools/testing/selftests/rseq/param_test.c
> +++ b/tools/testing/selftests/rseq/param_test.c
> @@ -38,7 +38,7 @@ 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';
> -
> +static bool opt_rseq_legacy;
>  static long long opt_reps = 5000;
>
>  static __thread __attribute__((tls_model("initial-exec")))
> @@ -481,7 +481,7 @@ void *test_percpu_spinlock_thread(void *
>         long long i, reps;
>
>         if (!opt_disable_rseq && thread_data->reg &&
> -           rseq_register_current_thread())
> +           __rseq_register_current_thread(true, opt_rseq_legacy))
>                 abort();
>         reps = thread_data->reps;
>         for (i = 0; i < reps; i++) {
> @@ -558,7 +558,7 @@ void *test_percpu_inc_thread(void *arg)
>         long long i, reps;
>
>         if (!opt_disable_rseq && thread_data->reg &&
> -           rseq_register_current_thread())
> +           __rseq_register_current_thread(true, opt_rseq_legacy))
>                 abort();
>         reps = thread_data->reps;
>         for (i = 0; i < reps; i++) {
> @@ -712,7 +712,7 @@ void *test_percpu_list_thread(void *arg)
>         long long i, reps;
>         struct percpu_list *list = (struct percpu_list *)arg;
>
> -       if (!opt_disable_rseq && rseq_register_current_thread())
> +       if (!opt_disable_rseq && __rseq_register_current_thread(true, opt_rseq_legacy))
>                 abort();
>
>         reps = opt_reps;
> @@ -895,7 +895,7 @@ void *test_percpu_buffer_thread(void *ar
>         long long i, reps;
>         struct percpu_buffer *buffer = (struct percpu_buffer *)arg;
>
> -       if (!opt_disable_rseq && rseq_register_current_thread())
> +       if (!opt_disable_rseq && __rseq_register_current_thread(true, opt_rseq_legacy))
>                 abort();
>
>         reps = opt_reps;
> @@ -1105,7 +1105,7 @@ void *test_percpu_memcpy_buffer_thread(v
>         long long i, reps;
>         struct percpu_memcpy_buffer *buffer = (struct percpu_memcpy_buffer *)arg;
>
> -       if (!opt_disable_rseq && rseq_register_current_thread())
> +       if (!opt_disable_rseq && __rseq_register_current_thread(true, opt_rseq_legacy))
>                 abort();
>
>         reps = opt_reps;
> @@ -1258,7 +1258,7 @@ void *test_membarrier_worker_thread(void
>         const int iters = opt_reps;
>         int i;
>
> -       if (rseq_register_current_thread()) {
> +       if (__rseq_register_current_thread(true, opt_rseq_legacy)) {
>                 fprintf(stderr, "Error: rseq_register_current_thread(...) failed(%d): %s\n",
>                         errno, strerror(errno));
>                 abort();
> @@ -1323,7 +1323,7 @@ void *test_membarrier_manager_thread(voi
>         intptr_t expect_a = 0, expect_b = 0;
>         int cpu_a = 0, cpu_b = 0;
>
> -       if (rseq_register_current_thread()) {
> +       if (__rseq_register_current_thread(true, opt_rseq_legacy)) {
>                 fprintf(stderr, "Error: rseq_register_current_thread(...) failed(%d): %s\n",
>                         errno, strerror(errno));
>                 abort();
> @@ -1475,6 +1475,7 @@ static void show_usage(int argc, char **
>         printf("        [-D M] Disable rseq for each M threads\n");
>         printf("        [-T test] Choose test: (s)pinlock, (l)ist, (b)uffer, (m)emcpy, (i)ncrement, membarrie(r)\n");
>         printf("        [-M] Push into buffer and memcpy buffer with memory barriers.\n");
> +       printf("        [-O] Test with optimized RSEQ\n");
>         printf("        [-v] Verbose output.\n");
>         printf("        [-h] Show this help.\n");
>         printf("\n");
> @@ -1602,6 +1603,9 @@ int main(int argc, char **argv)
>                 case 'M':
>                         opt_mo = RSEQ_MO_RELEASE;
>                         break;
> +               case 'L':
> +                       opt_rseq_legacy = true;
> +                       break;
>                 default:
>                         show_usage(argc, argv);
>                         goto error;
> @@ -1618,7 +1622,7 @@ int main(int argc, char **argv)
>         if (set_signal_handler())
>                 goto error;
>
> -       if (!opt_disable_rseq && rseq_register_current_thread())
> +       if (!opt_disable_rseq && __rseq_register_current_thread(true, opt_rseq_legacy))
>                 goto error;
>         if (!opt_disable_rseq && !rseq_validate_cpu_id()) {
>                 fprintf(stderr, "Error: cpu id getter unavailable\n");
> --- a/tools/testing/selftests/rseq/run_param_test.sh
> +++ b/tools/testing/selftests/rseq/run_param_test.sh
> @@ -34,6 +34,11 @@ REPS=1000
>  SLOW_REPS=100
>  NR_THREADS=$((6*${NR_CPUS}))
>
> +# Prevent GLIBC from registering RSEQ so the selftest can run in legacy and
> +# performance optimized mode.
> +GLIBC_TUNABLES="${GLIBC_TUNABLES:-}:glibc.pthread.rseq=0"
> +export GLIBC_TUNABLES
> +
>  function do_tests()
>  {
>         local i=0
> @@ -103,6 +108,40 @@ function inject_blocking()
>         NR_LOOPS=
>  }
>
> +echo "Testing in legacy RSEQ mode"
> +echo "Yield injection (25%)"
> +inject_blocking -m 4 -y -L
> +
> +echo "Yield injection (50%)"
> +inject_blocking -m 2 -y -L
> +
> +echo "Yield injection (100%)"
> +inject_blocking -m 1 -y -L
> +
> +echo "Kill injection (25%)"
> +inject_blocking -m 4 -k -L
> +
> +echo "Kill injection (50%)"
> +inject_blocking -m 2 -k -L
> +
> +echo "Kill injection (100%)"
> +inject_blocking -m 1 -k -L
> +
> +echo "Sleep injection (1ms, 25%)"
> +inject_blocking -m 4 -s 1 -L
> +
> +echo "Sleep injection (1ms, 50%)"
> +inject_blocking -m 2 -s 1 -L
> +
> +echo "Sleep injection (1ms, 100%)"
> +inject_blocking -m 1 -s 1 -L
> +
> +./check_optimized || {
> +    echo "Skipping optimized RSEQ mode test. Not supported";
> +    exit 0
> +}
> +
> +echo "Testing in optimized RSEQ mode"
>  echo "Yield injection (25%)"
>  inject_blocking -m 4 -y
>
> --- /dev/null
> +++ b/tools/testing/selftests/rseq/run_timeslice_test.sh
> @@ -0,0 +1,14 @@
> +#!/bin/bash
> +# SPDX-License-Identifier: GPL-2.0+
> +
> +# Prevent GLIBC from registering RSEQ so the selftest can run in legacy
> +# and performance optimized mode.
> +GLIBC_TUNABLES="${GLIBC_TUNABLES:-}:glibc.pthread.rseq=0"
> +export GLIBC_TUNABLES
> +
> +./check_optimized || {
> +    echo "Skipping optimized RSEQ mode test. Not supported";
> +    exit 0
> +}
> +
> +./slice_test
> --- a/tools/testing/selftests/rseq/slice_test.c
> +++ b/tools/testing/selftests/rseq/slice_test.c
> @@ -124,7 +124,7 @@ FIXTURE_SETUP(slice_ext)
>  {
>         cpu_set_t affinity;
>
> -       if (rseq_register_current_thread())
> +       if (__rseq_register_current_thread(true, false))
>                 SKIP(return, "RSEQ not supported\n");
>
>         if (prctl(PR_RSEQ_SLICE_EXTENSION, PR_RSEQ_SLICE_EXTENSION_SET,
>