On Sat, Nov 8, 2025 at 1:42 PM Sergey Matyukevich wrote:
>
> Add a test case to check ptrace behavior in the case when vector
> extension is supported by the system, but vector context is not
> yet enabled for the traced process.
>
> Signed-off-by: Sergey Matyukevich
Reviewed-by: Andy Chiu
> ---
> .../testing/selftests/riscv/vector/.gitignore | 1 +
> tools/testing/selftests/riscv/vector/Makefile | 5 +-
> .../testing/selftests/riscv/vector/v_ptrace.c | 85 +++
> 3 files changed, 90 insertions(+), 1 deletion(-)
> create mode 100644 tools/testing/selftests/riscv/vector/v_ptrace.c
>
> diff --git a/tools/testing/selftests/riscv/vector/.gitignore
> b/tools/testing/selftests/riscv/vector/.gitignore
> index 7d9c87cd0649..d21c03c3ee0e 100644
> --- a/tools/testing/selftests/riscv/vector/.gitignore
> +++ b/tools/testing/selftests/riscv/vector/.gitignore
> @@ -2,3 +2,4 @@ vstate_exec_nolibc
> vstate_prctl
> v_initval
> v_exec_initval_nolibc
> +v_ptrace
> diff --git a/tools/testing/selftests/riscv/vector/Makefile
> b/tools/testing/selftests/riscv/vector/Makefile
> index 6f7497f4e7b3..c14ad127e7fb 100644
> --- a/tools/testing/selftests/riscv/vector/Makefile
> +++ b/tools/testing/selftests/riscv/vector/Makefile
> @@ -2,7 +2,7 @@
> # Copyright (C) 2021 ARM Limited
> # Originally tools/testing/arm64/abi/Makefile
>
> -TEST_GEN_PROGS := v_initval vstate_prctl
> +TEST_GEN_PROGS := v_initval vstate_prctl v_ptrace
> TEST_GEN_PROGS_EXTENDED := vstate_exec_nolibc v_exec_initval_nolibc
>
> include ../../lib.mk
> @@ -26,3 +26,6 @@ $(OUTPUT)/v_initval: v_initval.c $(OUTPUT)/sys_hwprobe.o
> $(OUTPUT)/v_helpers.o
> $(OUTPUT)/v_exec_initval_nolibc: v_exec_initval_nolibc.c
> $(CC) -nostdlib -static -include ../../../../include/nolibc/nolibc.h \
> -Wall $(CFLAGS) $(LDFLAGS) $^ -o $@ -lgcc
> +
> +$(OUTPUT)/v_ptrace: v_ptrace.c $(OUTPUT)/sys_hwprobe.o $(OUTPUT)/v_helpers.o
> + $(CC) -static -o$@ $(CFLAGS) $(LDFLAGS) $^
> diff --git a/tools/testing/selftests/riscv/vector/v_ptrace.c
> b/tools/testing/selftests/riscv/vector/v_ptrace.c
> new file mode 100644
> index ..6a4b5a2ab4a2
> --- /dev/null
> +++ b/tools/testing/selftests/riscv/vector/v_ptrace.c
> @@ -0,0 +1,85 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +#include
> +#include
> +#include
> +#include
> +#include
> +#include
> +#include
> +
> +#include
> +#include
> +
> +#include "../../kselftest_harness.h"
> +#include "v_helpers.h"
> +
> +volatile unsigned long chld_lock;
> +
> +TEST(ptrace_v_not_enabled)
> +{
> + pid_t pid;
> +
> + if (!is_vector_supported())
> + SKIP(return, "Vector not supported");
> +
> + chld_lock = 1;
> + pid = fork();
> + ASSERT_LE(0, pid)
> + TH_LOG("fork: %m");
> +
> + if (pid == 0) {
> + while (chld_lock == 1)
> + asm volatile("" : : "g"(chld_lock) : "memory");
> +
> + asm volatile ("ebreak" : : : );
> + } else {
> + struct __riscv_v_regset_state *regset_data;
> + unsigned long vlenb;
> + size_t regset_size;
> + struct iovec iov;
> + int status;
> + int ret;
> +
> + asm volatile("csrr %[vlenb], vlenb" : [vlenb] "=r"(vlenb));
> +
> + ASSERT_GT(vlenb, 0)
> + TH_LOG("vlenb is not valid: %lu\n", vlenb);
> +
> + /* 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 ebreak */
> +
> + ASSERT_EQ(0, ptrace(PTRACE_CONT, pid, NULL, NULL));
> + ASSERT_EQ(pid, waitpid(pid, &status, 0));
> + ASSERT_TRUE(WIFSTOPPED(status));
> +
> + /* try to read vector registers from the tracee */
> +
> + regset_size = sizeof(*regset_data) + vlenb * 32;
> + regset_data = calloc(1, regset_size);
> +
> + iov.iov_base = regset_data;
> + iov.iov_len = regset_size;
> +
> + /* V extension is available, but not yet enabled for the
> tracee */
> +
> + errno = 0;
> + ret = ptrace(PTRACE_GETREGSET, pid, NT_RISCV_VECTOR, &iov);
> + ASSERT_EQ(ENODATA, errno);
> + ASSERT_EQ(-1, ret);
> +
> + /* cleanup */
> +
> + ASSERT_EQ(0, kill(pid, SIGKILL));
> + }
> +}
> +
> +TEST_HARNESS_MAIN
> --
> 2.51.0
>
