On Tue, Jun 25, 2024 at 05:54:05PM +0530, Dev Jain wrote:

+#include "../../kselftest.h"
+
+static void run_tests(pid_t child);
+
+static int do_child(void);
+
+#ifdef __aarch64__
+static bool have_sme(void)
+{
+	return getauxval(AT_HWCAP2) & HWCAP2_SME;
+}

+static void test_hw_debug(pid_t child, int type, const char *type_name)
+{
+	struct user_hwdebug_state state;
+	struct iovec iov;
+	int slots, arch, ret;
+
+	iov.iov_len = sizeof(state);
+	iov.iov_base = &state;
+
+	/* Should be able to read the values */
+	ret = ptrace(PTRACE_GETREGSET, child, type, &iov);
+	ksft_test_result(ret == 0, "read_%s\n", type_name);

This feels like it's pulling way too much stuff out into the header.  I
think some of this needs to be a C file that gets built for both
architectures with some mechanism they can use to run tests, and a
library of any shared tests.

+
+	if (ret == 0) {
+		/* Low 8 bits is the number of slots, next 4 bits the arch */
+		slots = state.dbg_info & 0xff;
+		arch = (state.dbg_info >> 8) & 0xf;
+
+		ksft_print_msg("%s version %d with %d slots\n", type_name,
+			       arch, slots);
+
+		/* Zero is not currently architecturally valid */
+		ksft_test_result(arch, "%s_arch_set\n", type_name);
+	} else {
+		ksft_test_result_skip("%s_arch_set\n", type_name);
+	}
+}
+#endif
+
+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 (sig == SIGTRAP)
+			ksft_print_msg("Child received SIGTRAP\n");
+
+		if (ptrace(PTRACE_GETSIGINFO, pid, NULL, &si)) {
+			if (errno == ESRCH)
+				goto disappeared;
+
+			if (errno == EINVAL)
+				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:
+		/* bust group-stop */
+		if (ptrace(PTRACE_CONT, pid, NULL, 0)) {
+			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);
+
+	ret = EXIT_SUCCESS;
+	run_tests(child);
+
+error:
+	kill(child, SIGKILL);
+
+disappeared:
+	return ret;
+}
-- 
2.39.2