On Thu, Oct 02, 2025 at 12:53:13AM -0500, Andy Chiu wrote: > Hi Yong-Xuan, > > I found some issues which deserve a re-roll: > > On Wed, Oct 1, 2025 at 6:15 AM Yong-Xuan Wang <[email protected]> > wrote: > > > > Add a test case that does some basic verification of the Vector ptrace > > interface. This forks a child process then using ptrace to inspect and > > manipulate the v31 register of the child. > > > > Signed-off-by: Yong-Xuan Wang <[email protected]> > > --- > > tools/testing/selftests/riscv/vector/Makefile | 5 +- > > .../selftests/riscv/vector/vstate_ptrace.c | 132 ++++++++++++++++++ > > 2 files changed, 136 insertions(+), 1 deletion(-) > > create mode 100644 tools/testing/selftests/riscv/vector/vstate_ptrace.c > > > > diff --git a/tools/testing/selftests/riscv/vector/Makefile > > b/tools/testing/selftests/riscv/vector/Makefile > > index 6f7497f4e7b3..45f25e9dd264 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 vsate_ptrace > > Please s/vsate_ptrace/vstate_ptrace > > Otherwise we will not get the program compiled > > > 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)/vstate_ptrace: vstate_ptrace.c $(OUTPUT)/sys_hwprobe.o > > $(OUTPUT)/v_helpers.o > > + $(CC) -static -o$@ $(CFLAGS) $(LDFLAGS) $^ > > diff --git a/tools/testing/selftests/riscv/vector/vstate_ptrace.c > > b/tools/testing/selftests/riscv/vector/vstate_ptrace.c > > new file mode 100644 > > index 000000000000..8a7bcf318e59 > > --- /dev/null > > +++ b/tools/testing/selftests/riscv/vector/vstate_ptrace.c > > @@ -0,0 +1,132 @@ > > +// SPDX-License-Identifier: GPL-2.0-only > > +#include <stdio.h> > > +#include <stdlib.h> > > +#include <asm/ptrace.h> > > +#include <linux/elf.h> > > +#include <sys/ptrace.h> > > +#include <sys/uio.h> > > +#include <sys/wait.h> > > +#include "../../kselftest.h" > > +#include "v_helpers.h" > > + > > +int parent_set_val, child_set_val; > > + > > +static long do_ptrace(enum __ptrace_request op, pid_t pid, long type, > > size_t size, void *data) > > +{ > > + struct iovec v_iovec = { > > + .iov_len = size, > > + .iov_base = data > > + }; > > + > > + return ptrace(op, pid, type, &v_iovec); > > +} > > + > > +static int do_child(void) > > +{ > > + int out; > > + > > + if (ptrace(PTRACE_TRACEME, -1, NULL, NULL)) { > > + ksft_perror("PTRACE_TRACEME failed\n"); > > + return EXIT_FAILURE; > > + } > > + > > + asm volatile (".option push\n\t" > > + ".option arch, +v\n\t" > > As mentioned before, please use ".option arch, +v,-c\n\t" or ".option > norvc\n\t" and +=4 when advancing the pc
arch -c should be avoided, there are cases when it does not always avoid using all compressed instructions. norvc should always do the right thing though. There is discussion at [1] about deprecating it (along with all variants of -ext). [1] https://inbox.sourceware.org/binutils/[email protected]/T/#t - Charlie > > > + "vsetivli x0, 1, e32, m1, ta, ma\n\t" > > + "vmv.s.x v31, %[in]\n\t" > > + "ebreak\n\t" > > + "vmv.x.s %[out], v31\n\t" > > + ".option pop\n\t" > > + : [out] "=r" (out) > > + : [in] "r" (child_set_val)); > > + > > + if (out != parent_set_val) > > + return EXIT_FAILURE; > > + > > + return EXIT_SUCCESS; > > +} > > + > > +static void do_parent(pid_t child) > > +{ > > + int status; > > + void *data = NULL; > > + > > + /* Attach to the child */ > > + while (waitpid(child, &status, 0)) { > > + if (WIFEXITED(status)) { > > + ksft_test_result(WEXITSTATUS(status) == 0, > > "SETREGSET vector\n"); > > + goto out; > > + } else if (WIFSTOPPED(status) && (WSTOPSIG(status) == > > SIGTRAP)) { > > + size_t size, t; > > unused variable t > > > + void *data, *v31; > > + struct __riscv_v_regset_state *v_regset_hdr; > > + struct user_regs_struct *gpreg; > > + > > + size = sizeof(*v_regset_hdr); > > + data = malloc(size); > > + if (!data) > > + goto out; > > + v_regset_hdr = (struct __riscv_v_regset_state > > *)data; > > + > > + if (do_ptrace(PTRACE_GETREGSET, child, > > NT_RISCV_VECTOR, size, data)) > > + goto out; > > + > > + ksft_print_msg("vlenb %ld\n", v_regset_hdr->vlenb); > > + data = realloc(data, size + v_regset_hdr->vlenb * > > 32); > > realloc may give a new pointer so v_regset_hdr has to be updated here > before the next use > > > + if (!data) > > + goto out; > > + v31 = (void *)(data + size + v_regset_hdr->vlenb * > > 31); > > + size += v_regset_hdr->vlenb * 32; > > + > > + if (do_ptrace(PTRACE_GETREGSET, child, > > NT_RISCV_VECTOR, size, data)) > > + goto out; > > + > > + ksft_test_result(*(int *)v31 == child_set_val, > > "GETREGSET vector\n"); > > + > > + *(int *)v31 = parent_set_val; > > + if (do_ptrace(PTRACE_SETREGSET, child, > > NT_RISCV_VECTOR, size, data)) > > + goto out; > > + > > + /* move the pc forward */ > > + size = sizeof(*gpreg); > > + data = realloc(data, size); > > + gpreg = (struct user_regs_struct *)data; > > + > > + if (do_ptrace(PTRACE_GETREGSET, child, NT_PRSTATUS, > > size, data)) > > + goto out; > > + > > + gpreg->pc += 2; > > + if (do_ptrace(PTRACE_SETREGSET, child, NT_PRSTATUS, > > size, data)) > > + goto out; > > + } > > + > > + ptrace(PTRACE_CONT, child, NULL, NULL); > > + } > > + > > +out: > > + free(data); > > +} > > + > > +int main(void) > > +{ > > + pid_t child; > > + > > + ksft_set_plan(2); > > + if (!is_vector_supported() && !is_xtheadvector_supported()) > > + ksft_exit_skip("Vector not supported\n"); > > + > > + srandom(getpid()); > > + parent_set_val = rand(); > > + child_set_val = rand(); > > + > > + child = fork(); > > + if (child < 0) > > + ksft_exit_fail_msg("Fork failed %d\n", child); > > + > > + if (!child) > > + return do_child(); > > + > > + do_parent(child); > > + > > + ksft_finished(); > > +} > > -- > > 2.43.0 > > > > Thanks, > Andy
