Re: [PATCH v2 1/4] kselftest/arm64: Add test coverage for NT_ARM_TLS

On 8/15/22 14:30, Mark Brown wrote:

In preparation for extending support for NT_ARM_TLS to cover additional TPIDRs add some tests for the existing interface. Do this in a generic ptrace test program to provide a place to collect additional tests in the future.

Signed-off-by: Mark Brown broonie@kernel.org

tools/testing/selftests/arm64/abi/.gitignore | 1 + tools/testing/selftests/arm64/abi/Makefile | 2 +- tools/testing/selftests/arm64/abi/ptrace.c | 165 +++++++++++++++++++ 3 files changed, 167 insertions(+), 1 deletion(-) create mode 100644 tools/testing/selftests/arm64/abi/ptrace.c

diff --git a/tools/testing/selftests/arm64/abi/.gitignore b/tools/testing/selftests/arm64/abi/.gitignore index b9e54417250d..12607c4580c6 100644 --- a/tools/testing/selftests/arm64/abi/.gitignore +++ b/tools/testing/selftests/arm64/abi/.gitignore @@ -1,2 +1,3 @@ +ptrace syscall-abi tpidr2 diff --git a/tools/testing/selftests/arm64/abi/Makefile b/tools/testing/selftests/arm64/abi/Makefile index c8d7f2495eb2..445ac2dac4ee 100644 --- a/tools/testing/selftests/arm64/abi/Makefile +++ b/tools/testing/selftests/arm64/abi/Makefile @@ -1,7 +1,7 @@ # SPDX-License-Identifier: GPL-2.0 # Copyright (C) 2021 ARM Limited -TEST_GEN_PROGS := syscall-abi tpidr2 +TEST_GEN_PROGS := ptrace syscall-abi tpidr2 include ../../lib.mk diff --git a/tools/testing/selftests/arm64/abi/ptrace.c b/tools/testing/selftests/arm64/abi/ptrace.c new file mode 100644 index 000000000000..4cc4d415b2e7 --- /dev/null +++ b/tools/testing/selftests/arm64/abi/ptrace.c @@ -0,0 +1,165 @@ +// SPDX-License-Identifier: GPL-2.0-only +/*

• • Copyright (C) 2021 ARM Limited.

I suppose 2021 -> 2022?

• */

+#include <errno.h> +#include <stdbool.h> +#include <stddef.h> +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <unistd.h> +#include <sys/auxv.h> +#include <sys/prctl.h> +#include <sys/ptrace.h> +#include <sys/types.h> +#include <sys/uio.h> +#include <sys/wait.h> +#include <asm/sigcontext.h> +#include <asm/ptrace.h>

+#include "../../kselftest.h"

+#define EXPECTED_TESTS 3

+#define MAX_TPIDRS 1

+static bool have_sme(void) +{

• return getauxval(AT_HWCAP2) & HWCAP2_SME;

+}

+static void test_tpidr(pid_t child) +{

• uint64_t read_val[MAX_TPIDRS];
• uint64_t write_val[MAX_TPIDRS];
• struct iovec read_iov, write_iov;
• int ret;
• read_iov.iov_base = read_val;
• write_iov.iov_base = write_val;
• /* Should be able to read a single TPIDR... */
• read_iov.iov_len = sizeof(uint64_t);
• ret = ptrace(PTRACE_GETREGSET, child, NT_ARM_TLS, &read_iov);
• ksft_test_result(ret == 0, "read_tpidr_one\n");
• /* ...write a new value.. */
• write_iov.iov_len = sizeof(uint64_t);
• write_val[0] = read_val[0]++;
• ret = ptrace(PTRACE_SETREGSET, child, NT_ARM_TLS, &write_iov);
• ksft_test_result(ret == 0, "write_tpidr_one\n");
• /* ...then read it back */
• ret = ptrace(PTRACE_GETREGSET, child, NT_ARM_TLS, &read_iov);
• ksft_test_result(ret == 0 && write_val[0] == read_val[0],

• 	 "verify_tpidr_one\n");
  

+}

+static int do_child(void) +{

• if (ptrace(PTRACE_TRACEME, -1, NULL, NULL))

• ksft_exit_fail_msg("PTRACE_TRACEME", strerror(errno));
  

• if (raise(SIGSTOP))

• ksft_exit_fail_msg("raise(SIGSTOP)", strerror(errno));
  

• return EXIT_SUCCESS;

+}

+static int do_parent(pid_t child) +{

• int ret = EXIT_FAILURE;
• pid_t pid;
• int status;
• siginfo_t si;
• /* Attach to the child */
• while (1) {

• int sig;
  

• pid = wait(&status);
  

• if (pid == -1) {
  

• 	perror("wait");
  

• 	goto error;
  

• }
  

• /*
  

•  * This should never happen but it's hard to flag in
  

•  * the framework.
  

•  */
  

• if (pid != child)
  

• 	continue;
  

• if (WIFEXITED(status) || WIFSIGNALED(status))
  

• 	ksft_exit_fail_msg("Child died unexpectedly\n");
  

• if (!WIFSTOPPED(status))
  

• 	goto error;
  

• sig = WSTOPSIG(status);
  

• if (ptrace(PTRACE_GETSIGINFO, pid, NULL, &si)) {
  

• 	if (errno == ESRCH)
  

• 		goto disappeared;
  

• 	if (errno == EINVAL) {
  

• 		sig = 0; /* bust group-stop */
  

• 		goto cont;
  

• 	}
  

• 	ksft_test_result_fail("PTRACE_GETSIGINFO: %s\n",
  

• 			      strerror(errno));
  

• 	goto error;
  

• }
  

• if (sig == SIGSTOP && si.si_code == SI_TKILL &&
  

•     si.si_pid == pid)
  

• 	break;
  

• cont:

• if (ptrace(PTRACE_CONT, pid, NULL, sig)) {
  

• 	if (errno == ESRCH)
  

• 		goto disappeared;
  

• 	ksft_test_result_fail("PTRACE_CONT: %s\n",
  

• 			      strerror(errno));
  

• 	goto error;
  

• }
  

• }
• ksft_print_msg("Parent is %d, child is %d\n", getpid(), child);
• test_tpidr(child);
• ret = EXIT_SUCCESS;

+error:

• kill(child, SIGKILL);

+disappeared:

• return ret;

+}

+int main(void) +{

• int ret = EXIT_SUCCESS;
• pid_t child;
• srandom(getpid());
• ksft_print_header();
• ksft_set_plan(EXPECTED_TESTS);
• child = fork();
• if (!child)

• return do_child();
  

• if (do_parent(child))

• ret = EXIT_FAILURE;
  

• ksft_print_cnts();
• return ret;

+}