[PATCH -next v21 26/27] selftests: Test RISC-V Vector prctl interface

Andy Chiu
2023-06-05T15:43:25Z

This add a test for prctl interface that controls the use of userspace
Vector.

Signed-off-by: Andy Chiu <andy.chiu@sifive.com>
---
tools/testing/selftests/riscv/Makefile | 2 +-
.../testing/selftests/riscv/vector/.gitignore | 2 +
tools/testing/selftests/riscv/vector/Makefile | 15 ++
.../riscv/vector/vstate_exec_nolibc.c | 111 ++++++++++
.../selftests/riscv/vector/vstate_prctl.c | 189 ++++++++++++++++++
5 files changed, 318 insertions(+), 1 deletion(-)
create mode 100644 tools/testing/selftests/riscv/vector/.gitignore
create mode 100644 tools/testing/selftests/riscv/vector/Makefile
create mode 100644 tools/testing/selftests/riscv/vector/vstate_exec_nolibc.c
create mode 100644 tools/testing/selftests/riscv/vector/vstate_prctl.c

diff --git a/tools/testing/selftests/riscv/Makefile b/tools/testing/selftests/riscv/Makefile
index 32a72902d045..9dd629cc86aa 100644
--- a/tools/testing/selftests/riscv/Makefile
+++ b/tools/testing/selftests/riscv/Makefile
@@ -5,7 +5,7 @@
ARCH ?= $(shell uname -m 2>/dev/null || echo not)

ifneq (,$(filter $(ARCH),riscv))
-RISCV_SUBTARGETS ?= hwprobe
+RISCV_SUBTARGETS ?= hwprobe vector
else
RISCV_SUBTARGETS :=
endif
diff --git a/tools/testing/selftests/riscv/vector/.gitignore b/tools/testing/selftests/riscv/vector/.gitignore
new file mode 100644
index 000000000000..4f2b4e8a3b08
--- /dev/null
+++ b/tools/testing/selftests/riscv/vector/.gitignore
@@ -0,0 +1,2 @@
+vstate_exec_nolibc
+vstate_prctl
diff --git a/tools/testing/selftests/riscv/vector/Makefile b/tools/testing/selftests/riscv/vector/Makefile
new file mode 100644
index 000000000000..cd6e80bf995d
--- /dev/null
+++ b/tools/testing/selftests/riscv/vector/Makefile
@@ -0,0 +1,15 @@
+# SPDX-License-Identifier: GPL-2.0
+# Copyright (C) 2021 ARM Limited
+# Originally tools/testing/arm64/abi/Makefile
+
+TEST_GEN_PROGS := vstate_prctl
+TEST_GEN_PROGS_EXTENDED := vstate_exec_nolibc
+
+include ../../lib.mk
+
+$(OUTPUT)/vstate_prctl: vstate_prctl.c ../hwprobe/sys_hwprobe.S
+ $(CC) -static -o$@ $(CFLAGS) $(LDFLAGS) $^
+
+$(OUTPUT)/vstate_exec_nolibc: vstate_exec_nolibc.c
+ $(CC) -nostdlib -static -include ../../../../include/nolibc/nolibc.h \
+ -Wall $(CFLAGS) $(LDFLAGS) $^ -o $@ -lgcc
diff --git a/tools/testing/selftests/riscv/vector/vstate_exec_nolibc.c b/tools/testing/selftests/riscv/vector/vstate_exec_nolibc.c
new file mode 100644
index 000000000000..5cbc392944a6
--- /dev/null
+++ b/tools/testing/selftests/riscv/vector/vstate_exec_nolibc.c
@@ -0,0 +1,111 @@
+// SPDX-License-Identifier: GPL-2.0-only
+#include <sys/prctl.h>
+
+#define THIS_PROGRAM "./vstate_exec_nolibc"
+
+int main(int argc, char **argv)
+{
+ int rc, pid, status, test_inherit = 0;
+ long ctrl, ctrl_c;
+ char *exec_argv[2], *exec_envp[2];
+
+ if (argc > 1)
+ test_inherit = 1;
+
+ ctrl = my_syscall1(__NR_prctl, PR_RISCV_V_GET_CONTROL);
+ if (ctrl < 0) {
+ puts("PR_RISCV_V_GET_CONTROL is not supported\n");
+ return ctrl;
+ }
+
+ if (test_inherit) {
+ pid = fork();
+ if (pid == -1) {
+ puts("fork failed\n");
+ exit(-1);
+ }
+
+ /* child */
+ if (!pid) {
+ exec_argv[0] = THIS_PROGRAM;
+ exec_argv[1] = NULL;
+ exec_envp[0] = NULL;
+ exec_envp[1] = NULL;
+ /* launch the program again to check inherit */
+ rc = execve(THIS_PROGRAM, exec_argv, exec_envp);
+ if (rc) {
+ puts("child execve failed\n");
+ exit(-1);
+ }
+ }
+
+ } else {
+ pid = fork();
+ if (pid == -1) {
+ puts("fork failed\n");
+ exit(-1);
+ }
+
+ if (!pid) {
+ rc = my_syscall1(__NR_prctl, PR_RISCV_V_GET_CONTROL);
+ if (rc != ctrl) {
+ puts("child's vstate_ctrl not equal to parent's\n");
+ exit(-1);
+ }
+ asm volatile (".option push\n\t"
+ ".option arch, +v\n\t"
+ "vsetvli x0, x0, e32, m8, ta, ma\n\t"
+ ".option pop\n\t"
+ );
+ exit(ctrl);
+ }
+ }
+
+ rc = waitpid(-1, &status, 0);
+
+ if (WIFEXITED(status) && WEXITSTATUS(status) == -1) {
+ puts("child exited abnormally\n");
+ exit(-1);
+ }
+
+ if (WIFSIGNALED(status)) {
+ if (WTERMSIG(status) != SIGILL) {
+ puts("child was terminated by unexpected signal\n");
+ exit(-1);
+ }
+
+ if ((ctrl & PR_RISCV_V_VSTATE_CTRL_CUR_MASK) != PR_RISCV_V_VSTATE_CTRL_OFF) {
+ puts("child signaled by illegal V access but vstate_ctrl is not off\n");
+ exit(-1);
+ }
+
+ /* child terminated, and its vstate_ctrl is off */
+ exit(ctrl);
+ }
+
+ ctrl_c = WEXITSTATUS(status);
+ if (test_inherit) {
+ if (ctrl & PR_RISCV_V_VSTATE_CTRL_INHERIT) {
+ if (!(ctrl_c & PR_RISCV_V_VSTATE_CTRL_INHERIT)) {
+ puts("parent has inherit bit, but child has not\n");
+ exit(-1);
+ }
+ }
+ rc = (ctrl & PR_RISCV_V_VSTATE_CTRL_NEXT_MASK) >> 2;
+ if (rc != PR_RISCV_V_VSTATE_CTRL_DEFAULT) {
+ if (rc != (ctrl_c & PR_RISCV_V_VSTATE_CTRL_CUR_MASK)) {
+ puts("parent's next setting does not equal to child's\n");
+ exit(-1);
+ }
+
+ if (!(ctrl & PR_RISCV_V_VSTATE_CTRL_INHERIT)) {
+ if ((ctrl_c & PR_RISCV_V_VSTATE_CTRL_NEXT_MASK) !=
+ PR_RISCV_V_VSTATE_CTRL_DEFAULT) {
+ puts("must clear child's next vstate_ctrl if !inherit\n");
+ exit(-1);
+ }
+ }
+ }
+ }
+ return ctrl;
+}
diff --git a/tools/testing/selftests/riscv/vector/vstate_prctl.c b/tools/testing/selftests/riscv/vector/vstate_prctl.c
new file mode 100644
index 000000000000..b348b475be57
--- /dev/null
+++ b/tools/testing/selftests/riscv/vector/vstate_prctl.c
@@ -0,0 +1,189 @@
+// SPDX-License-Identifier: GPL-2.0-only
+#include <sys/prctl.h>
+#include <unistd.h>
+#include <asm/hwprobe.h>
+#include <errno.h>
+#include <sys/wait.h>
+
+#include "../../kselftest.h"
+
+/*
+ * Rather than relying on having a new enough libc to define this, just do it
+ * ourselves. This way we don't need to be coupled to a new-enough libc to
+ * contain the call.
+ */
+long riscv_hwprobe(struct riscv_hwprobe *pairs, size_t pair_count,
+ size_t cpu_count, unsigned long *cpus, unsigned int flags);
+
+#define NEXT_PROGRAM "./vstate_exec_nolibc"
+static int launch_test(int test_inherit)
+{
+ char *exec_argv[3], *exec_envp[1];
+ int rc, pid, status;
+
+ pid = fork();
+ if (pid < 0) {
+ ksft_test_result_fail("fork failed %d", pid);
+ return -1;
+ }
+
+ if (!pid) {
+ exec_argv[0] = NEXT_PROGRAM;
+ exec_argv[1] = test_inherit != 0 ? "x" : NULL;
+ exec_argv[2] = NULL;
+ exec_envp[0] = NULL;
+ /* launch the program again to check inherit */
+ rc = execve(NEXT_PROGRAM, exec_argv, exec_envp);
+ if (rc) {
+ perror("execve");
+ ksft_test_result_fail("child execve failed %d\n", rc);
+ exit(-1);
+ }
+ }
+
+ rc = waitpid(-1, &status, 0);
+ if (rc < 0) {
+ ksft_test_result_fail("waitpid failed\n");
+ return -3;
+ }
+
+ if ((WIFEXITED(status) && WEXITSTATUS(status) == -1) ||
+ WIFSIGNALED(status)) {
+ ksft_test_result_fail("child exited abnormally\n");
+ return -4;
+ }
+
+ return WEXITSTATUS(status);
+}
+
+int test_and_compare_child(long provided, long expected, int inherit)
+{
+ int rc;
+
+ rc = prctl(PR_RISCV_V_SET_CONTROL, provided);
+ if (rc != 0) {
+ ksft_test_result_fail("prctl with provided arg %lx failed with code %d\n",
+ provided, rc);
+ return -1;
+ }
+ rc = launch_test(inherit);
+ if (rc != expected) {
+ ksft_test_result_fail("Test failed, check %d != %d\n", rc,
+ expected);
+ return -2;
+ }
+ return 0;
+}
+
+#define PR_RISCV_V_VSTATE_CTRL_CUR_SHIFT 0
+#define PR_RISCV_V_VSTATE_CTRL_NEXT_SHIFT 2
+
+int main(void)
+{
+ struct riscv_hwprobe pair;
+ long flag, expected;
+ long rc;
+
+ pair.key = RISCV_HWPROBE_KEY_IMA_EXT_0;
+ rc = riscv_hwprobe(&pair, 1, 0, NULL, 0);
+ if (rc < 0) {
+ ksft_test_result_fail("hwprobe() failed with %d\n", rc);
+ return -1;
+ }
+
+ if (pair.key != RISCV_HWPROBE_KEY_IMA_EXT_0) {
+ ksft_test_result_fail("hwprobe cannot probe RISCV_HWPROBE_KEY_IMA_EXT_0\n");
+ return -2;
+ }
+
+ if (!(pair.value & RISCV_HWPROBE_IMA_V)) {
+ rc = prctl(PR_RISCV_V_GET_CONTROL);
+ if (rc != -1 || errno != EINVAL) {
+ ksft_test_result_fail("GET_CONTROL should fail on kernel/hw without V\n");
+ return -3;
+ }
+
+ rc = prctl(PR_RISCV_V_SET_CONTROL, PR_RISCV_V_VSTATE_CTRL_ON);
+ if (rc != -1 || errno != EINVAL) {
+ ksft_test_result_fail("GET_CONTROL should fail on kernel/hw without V\n");
+ return -4;
+ }
+
+ ksft_test_result_skip("Vector not supported\n");
+ return 0;
+ }
+
+ flag = PR_RISCV_V_VSTATE_CTRL_ON;
+ rc = prctl(PR_RISCV_V_SET_CONTROL, flag);
+ if (rc != 0) {
+ ksft_test_result_fail("Enabling V for current should always success\n");
+ return -5;
+ }
+
+ flag = PR_RISCV_V_VSTATE_CTRL_OFF;
+ rc = prctl(PR_RISCV_V_SET_CONTROL, flag);
+ if (rc != -1 || errno != EPERM) {
+ ksft_test_result_fail("Disabling current's V alive must fail with EPERM(%d)\n",
+ errno);
+ return -5;
+ }
+
+ /* Turn on next's vector explicitly and test */
+ flag = PR_RISCV_V_VSTATE_CTRL_ON << PR_RISCV_V_VSTATE_CTRL_NEXT_SHIFT;
+ if (test_and_compare_child(flag, PR_RISCV_V_VSTATE_CTRL_ON, 0))
+ return -6;
+
+ /* Turn off next's vector explicitly and test */
+ flag = PR_RISCV_V_VSTATE_CTRL_OFF << PR_RISCV_V_VSTATE_CTRL_NEXT_SHIFT;
+ if (test_and_compare_child(flag, PR_RISCV_V_VSTATE_CTRL_OFF, 0))
+ return -7;
+
+ /* Turn on next's vector explicitly and test inherit */
+ flag = PR_RISCV_V_VSTATE_CTRL_ON << PR_RISCV_V_VSTATE_CTRL_NEXT_SHIFT;
+ flag |= PR_RISCV_V_VSTATE_CTRL_INHERIT;
+ expected = flag | PR_RISCV_V_VSTATE_CTRL_ON;
+ if (test_and_compare_child(flag, expected, 0))
+ return -8;
+
+ if (test_and_compare_child(flag, expected, 1))
+ return -9;
+
+ /* Turn off next's vector explicitly and test inherit */
+ flag = PR_RISCV_V_VSTATE_CTRL_OFF << PR_RISCV_V_VSTATE_CTRL_NEXT_SHIFT;
+ flag |= PR_RISCV_V_VSTATE_CTRL_INHERIT;
+ expected = flag | PR_RISCV_V_VSTATE_CTRL_OFF;
+ if (test_and_compare_child(flag, expected, 0))
+ return -10;
+
+ if (test_and_compare_child(flag, expected, 1))
+ return -11;
+
+ /* arguments should fail with EINVAL */
+ rc = prctl(PR_RISCV_V_SET_CONTROL, 0xff0);
+ if (rc != -1 || errno != EINVAL) {
+ ksft_test_result_fail("Undefined control argument should return EINVAL\n");
+ return -12;
+ }
+
+ rc = prctl(PR_RISCV_V_SET_CONTROL, 0x3);
+ if (rc != -1 || errno != EINVAL) {
+ ksft_test_result_fail("Undefined control argument should return EINVAL\n");
+ return -12;
+ }
+
+ rc = prctl(PR_RISCV_V_SET_CONTROL, 0xc);
+ if (rc != -1 || errno != EINVAL) {
+ ksft_test_result_fail("Undefined control argument should return EINVAL\n");
+ return -12;
+ }
+
+ rc = prctl(PR_RISCV_V_SET_CONTROL, 0xc);
+ if (rc != -1 || errno != EINVAL) {
+ ksft_test_result_fail("Undefined control argument should return EINVAL\n");
+ return -12;
+ }
+
+ ksft_test_result_pass("tests for riscv_v_vstate_ctrl pass\n");
+ ksft_exit_pass();
+ return 0;
+}
--
2.17.1