[PATCH v5 8/9] selftests: riscv: verify ptrace rejects invalid vector csr inputs

Sergey Matyukevich
2025-12-14T16:36:01Z

Add a test to v_ptrace test suite to verify that ptrace rejects the
invalid input combinations of vector csr registers. Use kselftest
fixture variants to create multiple invalid inputs for the test.

Signed-off-by: Sergey Matyukevich <geomatsi@gmail.com>
---
.../riscv/vector/validate_v_ptrace.c | 318 ++++++++++++++++++
1 file changed, 318 insertions(+)

diff --git a/tools/testing/selftests/riscv/vector/validate_v_ptrace.c b/tools/testing/selftests/riscv/vector/validate_v_ptrace.c
index 2dd0c727e520..623b13e7582e 100644
--- a/tools/testing/selftests/riscv/vector/validate_v_ptrace.c
+++ b/tools/testing/selftests/riscv/vector/validate_v_ptrace.c
@@ -336,4 +336,322 @@ TEST(ptrace_v_syscall_clobbering)
}
}

+FIXTURE(v_csr_invalid)
+{
+};
+
+FIXTURE_SETUP(v_csr_invalid)
+{
+}
+
+FIXTURE_TEARDOWN(v_csr_invalid)
+{
+}
+
+#define VECTOR_1_0 (1UL << 0)
+#define XTHEAD_VECTOR_0_7 (1UL << 1)
+
+#define vector_test(x) ((x) & VECTOR_1_0)
+#define xthead_test(x) ((x) & XTHEAD_VECTOR_0_7)
+
+/* modifications of the initial vsetvli settings */
+FIXTURE_VARIANT(v_csr_invalid)
+{
+ unsigned long vstart;
+ unsigned long vl;
+ unsigned long vtype;
+ unsigned long vcsr;
+ unsigned long vlenb_mul;
+ unsigned long vlenb_min;
+ unsigned long vlenb_max;
+ unsigned long spec;
+};
+
+/* unexpected vlenb value */
+FIXTURE_VARIANT_ADD(v_csr_invalid, new_vlenb)
+{
+ .vstart = 0x0,
+ .vl = 0x0,
+ .vtype = 0x3,
+ .vcsr = 0x0,
+ .vlenb_mul = 0x2,
+ .vlenb_min = 0x0,
+ .vlenb_max = 0x0,
+ .spec = VECTOR_1_0 | XTHEAD_VECTOR_0_7,
+};
+
+/* invalid reserved bits in vcsr */
+FIXTURE_VARIANT_ADD(v_csr_invalid, vcsr_invalid_reserved_bits)
+{
+ .vstart = 0x0,
+ .vl = 0x0,
+ .vtype = 0x3,
+ .vcsr = 0x1UL << 8,
+ .vlenb_mul = 0x1,
+ .vlenb_min = 0x0,
+ .vlenb_max = 0x0,
+ .spec = VECTOR_1_0 | XTHEAD_VECTOR_0_7,
+};
+
+/* invalid reserved bits in vtype */
+FIXTURE_VARIANT_ADD(v_csr_invalid, vtype_invalid_reserved_bits)
+{
+ .vstart = 0x0,
+ .vl = 0x0,
+ .vtype = (0x1UL << 8) | 0x3,
+ .vcsr = 0x0,
+ .vlenb_mul = 0x1,
+ .vlenb_min = 0x0,
+ .vlenb_max = 0x0,
+ .spec = VECTOR_1_0 | XTHEAD_VECTOR_0_7,
+};
+
+/* set vill bit */
+FIXTURE_VARIANT_ADD(v_csr_invalid, invalid_vill_bit)
+{
+ .vstart = 0x0,
+ .vl = 0x0,
+ .vtype = (0x1UL << (__riscv_xlen - 1)) | 0x3,
+ .vcsr = 0x0,
+ .vlenb_mul = 0x1,
+ .vlenb_min = 0x0,
+ .vlenb_max = 0x0,
+ .spec = VECTOR_1_0 | XTHEAD_VECTOR_0_7,
+};
+
+/* reserved vsew value: vsew > 3 */
+FIXTURE_VARIANT_ADD(v_csr_invalid, reserved_vsew)
+{
+ .vstart = 0x0,
+ .vl = 0x0,
+ .vtype = 0x4UL << 3,
+ .vcsr = 0x0,
+ .vlenb_mul = 0x1,
+ .vlenb_min = 0x0,
+ .vlenb_max = 0x0,
+ .spec = VECTOR_1_0,
+};
+
+/* XTheadVector: unsupported non-zero VEDIV value */
+FIXTURE_VARIANT_ADD(v_csr_invalid, reserved_vediv)
+{
+ .vstart = 0x0,
+ .vl = 0x0,
+ .vtype = 0x3UL << 5,
+ .vcsr = 0x0,
+ .vlenb_mul = 0x1,
+ .vlenb_min = 0x0,
+ .vlenb_max = 0x0,
+ .spec = XTHEAD_VECTOR_0_7,
+};
+
+/* reserved vlmul value: vlmul == 4 */
+FIXTURE_VARIANT_ADD(v_csr_invalid, reserved_vlmul)
+{
+ .vstart = 0x0,
+ .vl = 0x0,
+ .vtype = 0x4,
+ .vcsr = 0x0,
+ .vlenb_mul = 0x1,
+ .vlenb_min = 0x0,
+ .vlenb_max = 0x0,
+ .spec = VECTOR_1_0,
+};
+
+/* invalid fractional LMUL for VLEN <= 256: LMUL= 1/8, SEW = 64 */
+FIXTURE_VARIANT_ADD(v_csr_invalid, frac_lmul1)
+{
+ .vstart = 0x0,
+ .vl = 0x0,
+ .vtype = 0x1d,
+ .vcsr = 0x0,
+ .vlenb_mul = 0x1,
+ .vlenb_min = 0x0,
+ .vlenb_max = 0x20,
+ .spec = VECTOR_1_0,
+};
+
+/* invalid integral LMUL for VLEN <= 16: LMUL= 2, SEW = 64 */
+FIXTURE_VARIANT_ADD(v_csr_invalid, int_lmul1)
+{
+ .vstart = 0x0,
+ .vl = 0x0,
+ .vtype = 0x19,
+ .vcsr = 0x0,
+ .vlenb_mul = 0x1,
+ .vlenb_min = 0x0,
+ .vlenb_max = 0x2,
+ .spec = VECTOR_1_0,
+};
+
+/* XTheadVector: invalid integral LMUL for VLEN <= 16: LMUL= 2, SEW = 64 */
+FIXTURE_VARIANT_ADD(v_csr_invalid, int_lmul2)
+{
+ .vstart = 0x0,
+ .vl = 0x0,
+ .vtype = 0xd,
+ .vcsr = 0x0,
+ .vlenb_mul = 0x1,
+ .vlenb_min = 0x0,
+ .vlenb_max = 0x2,
+ .spec = XTHEAD_VECTOR_0_7,
+};
+
+/* invalid VL for VLEN <= 128: LMUL= 2, SEW = 64, VL = 8 */
+FIXTURE_VARIANT_ADD(v_csr_invalid, vl1)
+{
+ .vstart = 0x0,
+ .vl = 0x8,
+ .vtype = 0x19,
+ .vcsr = 0x0,
+ .vlenb_mul = 0x1,
+ .vlenb_min = 0x0,
+ .vlenb_max = 0x10,
+ .spec = VECTOR_1_0,
+};
+
+/* XTheadVector: invalid VL for VLEN <= 128: LMUL= 2, SEW = 64, VL = 8 */
+FIXTURE_VARIANT_ADD(v_csr_invalid, vl2)
+{
+ .vstart = 0x0,
+ .vl = 0x8,
+ .vtype = 0xd,
+ .vcsr = 0x0,
+ .vlenb_mul = 0x1,
+ .vlenb_min = 0x0,
+ .vlenb_max = 0x10,
+ .spec = XTHEAD_VECTOR_0_7,
+};
+
+TEST_F(v_csr_invalid, ptrace_v_invalid_values)
+{
+ unsigned long vlenb;
+ pid_t pid;
+
+ if (!is_vector_supported() && !is_xtheadvector_supported())
+ SKIP(return, "Vectors not supported");
+
+ if (is_vector_supported() && !vector_test(variant->spec))
+ SKIP(return, "Test not supported for Vector");
+
+ if (is_xtheadvector_supported() && !xthead_test(variant->spec))
+ SKIP(return, "Test not supported for XTheadVector");
+
+ vlenb = get_vr_len();
+
+ if (variant->vlenb_min) {
+ if (vlenb < variant->vlenb_min)
+ SKIP(return, "This test does not support VLEN < %lu\n",
+ variant->vlenb_min * 8);
+ }
+
+ if (variant->vlenb_max) {
+ if (vlenb > variant->vlenb_max)
+ SKIP(return, "This test does not support VLEN > %lu\n",
+ variant->vlenb_max * 8);
+ }
+
+ chld_lock = 1;
+ pid = fork();
+ ASSERT_LE(0, pid)
+ TH_LOG("fork: %m");
+
+ if (pid == 0) {
+ unsigned long vl;
+
+ while (chld_lock == 1)
+ asm volatile("" : : "g"(chld_lock) : "memory");
+
+ if (is_xtheadvector_supported()) {
+ asm volatile (
+ // 0 | zimm[10:0] | rs1 | 1 1 1 | rd |1010111| vsetvli
+ // vsetvli t4, x0, e16, m2, d1
+ ".4byte 0b00000000010100000111111011010111\n"
+ "mv %[new_vl], t4\n"
+ : [new_vl] "=r" (vl) : : "t4");
+ } else {
+ asm volatile (
+ ".option push\n"
+ ".option arch, +zve32x\n"
+ "vsetvli %[new_vl], x0, e16, m2, tu, mu\n"
+ ".option pop\n"
+ : [new_vl] "=r"(vl) : : );
+ }
+
+ while (1) {
+ asm volatile (
+ ".option push\n"
+ ".option norvc\n"
+ "ebreak\n"
+ "nop\n"
+ ".option pop\n");
+ }
+ } else {
+ struct __riscv_v_regset_state *regset_data;
+ size_t regset_size;
+ struct iovec iov;
+ int status;
+ int ret;
+
+ /* attach */
+
+ ASSERT_EQ(0, ptrace(PTRACE_ATTACH, pid, NULL, NULL));
+ ASSERT_EQ(pid, waitpid(pid, &status, 0));
+ ASSERT_TRUE(WIFSTOPPED(status));
+
+ /* unlock */
+
+ ASSERT_EQ(0, ptrace(PTRACE_POKEDATA, pid, &chld_lock, 0));
+
+ /* resume and wait for the 1st ebreak */
+
+ ASSERT_EQ(0, ptrace(PTRACE_CONT, pid, NULL, NULL));
+ ASSERT_EQ(pid, waitpid(pid, &status, 0));
+ ASSERT_TRUE(WIFSTOPPED(status));
+
+ /* read tracee vector csr regs using ptrace GETREGSET */
+
+ regset_size = sizeof(*regset_data) + vlenb * 32;
+ regset_data = calloc(1, regset_size);
+
+ iov.iov_base = regset_data;
+ iov.iov_len = regset_size;
+
+ ASSERT_EQ(0, ptrace(PTRACE_GETREGSET, pid, NT_RISCV_VECTOR, &iov));
+
+ /* verify initial vsetvli settings */
+
+ if (is_xtheadvector_supported()) {
+ EXPECT_EQ(5UL, regset_data->vtype);
+ } else {
+ EXPECT_EQ(9UL, regset_data->vtype);
+ }
+
+ EXPECT_EQ(regset_data->vlenb, regset_data->vl);
+ EXPECT_EQ(vlenb, regset_data->vlenb);
+ EXPECT_EQ(0UL, regset_data->vstart);
+ EXPECT_EQ(0UL, regset_data->vcsr);
+
+ /* apply invalid settings from fixture variants */
+
+ regset_data->vlenb *= variant->vlenb_mul;
+ regset_data->vstart = variant->vstart;
+ regset_data->vtype = variant->vtype;
+ regset_data->vcsr = variant->vcsr;
+ regset_data->vl = variant->vl;
+
+ iov.iov_base = regset_data;
+ iov.iov_len = regset_size;
+
+ errno = 0;
+ ret = ptrace(PTRACE_SETREGSET, pid, NT_RISCV_VECTOR, &iov);
+ ASSERT_EQ(errno, EINVAL);
+ ASSERT_EQ(ret, -1);
+
+ /* cleanup */
+
+ ASSERT_EQ(0, kill(pid, SIGKILL));
+ }
+}
+
TEST_HARNESS_MAIN
--
2.52.0