Add two tests for TRAP_* signal codes for SIGTRAP.

- ptrace__breakpoint_siginfo tests that a SIGTRAP for a software breakpoint
  in userland triggers a SIGTRAP with a signal code of TRAP_BRKPT.
- ptrace__step_siginfo tests that a SIGTRAP reported for a step after
  stepping via PT_STEP or PT_SETSTEP has a signal code of TRAP_TRACE.

tests/sys/kern/ptrace_test.c

@@ -3488,6 +3488,110 @@ ATF_TC_BODY(ptrace__PT_STEP_with_signal, tc)
 	ATF_REQUIRE(errno == ECHILD);
 }
 
+#ifdef HAVE_BREAKPOINT
+/*
+ * Verify that a SIGTRAP event with the TRAP_BRKPT code is reported
+ * for a breakpoint trap.
+ */
+ATF_TC_WITHOUT_HEAD(ptrace__breakpoint_siginfo);
+ATF_TC_BODY(ptrace__breakpoint_siginfo, tc)
+{
+	struct ptrace_lwpinfo pl;
+	pid_t fpid, wpid;
+	int status;
+
+	ATF_REQUIRE((fpid = fork()) != -1);
+	if (fpid == 0) {
+		trace_me();
+		breakpoint();
+		exit(1);
+	}
+
+	/* The first wait() should report the stop from SIGSTOP. */
+	wpid = waitpid(fpid, &status, 0);
+	ATF_REQUIRE(wpid == fpid);
+	ATF_REQUIRE(WIFSTOPPED(status));
+	ATF_REQUIRE(WSTOPSIG(status) == SIGSTOP);
+
+	/* Continue the child ignoring the SIGSTOP. */
+	ATF_REQUIRE(ptrace(PT_CONTINUE, fpid, (caddr_t)1, 0) == 0);
+
+	/* The second wait() should report hitting the breakpoint. */
+	wpid = waitpid(fpid, &status, 0);
+	ATF_REQUIRE(wpid == fpid);
+	ATF_REQUIRE(WIFSTOPPED(status));
+	ATF_REQUIRE(WSTOPSIG(status) == SIGTRAP);
+
+	ATF_REQUIRE(ptrace(PT_LWPINFO, wpid, (caddr_t)&pl, sizeof(pl)) != -1);
+	ATF_REQUIRE((pl.pl_flags & PL_FLAG_SI) != 0);
+	ATF_REQUIRE(pl.pl_siginfo.si_signo == SIGTRAP);
+	ATF_REQUIRE(pl.pl_siginfo.si_code == TRAP_BRKPT);
+
+	/* Kill the child process. */
+	ATF_REQUIRE(ptrace(PT_KILL, fpid, 0, 0) == 0);
+
+	/* The last wait() should report the SIGKILL. */
+	wpid = waitpid(fpid, &status, 0);
+	ATF_REQUIRE(wpid == fpid);
+	ATF_REQUIRE(WIFSIGNALED(status));
+	ATF_REQUIRE(WTERMSIG(status) == SIGKILL);
+
+	wpid = wait(&status);
+	ATF_REQUIRE(wpid == -1);
+	ATF_REQUIRE(errno == ECHILD);
+}
+#endif /* HAVE_BREAKPOINT */
+
+/*
+ * Verify that a SIGTRAP event with the TRAP_TRACE code is reported
+ * for a single-step trap from PT_STEP.
+ */
+ATF_TC_WITHOUT_HEAD(ptrace__step_siginfo);
+ATF_TC_BODY(ptrace__step_siginfo, tc)
+{
+	struct ptrace_lwpinfo pl;
+	pid_t fpid, wpid;
+	int status;
+
+	ATF_REQUIRE((fpid = fork()) != -1);
+	if (fpid == 0) {
+		trace_me();
+		exit(1);
+	}
+
+	/* The first wait() should report the stop from SIGSTOP. */
+	wpid = waitpid(fpid, &status, 0);
+	ATF_REQUIRE(wpid == fpid);
+	ATF_REQUIRE(WIFSTOPPED(status));
+	ATF_REQUIRE(WSTOPSIG(status) == SIGSTOP);
+
+	/* Step the child ignoring the SIGSTOP. */
+	ATF_REQUIRE(ptrace(PT_STEP, fpid, (caddr_t)1, 0) == 0);
+
+	/* The second wait() should report a single-step trap. */
+	wpid = waitpid(fpid, &status, 0);
+	ATF_REQUIRE(wpid == fpid);
+	ATF_REQUIRE(WIFSTOPPED(status));
+	ATF_REQUIRE(WSTOPSIG(status) == SIGTRAP);
+
+	ATF_REQUIRE(ptrace(PT_LWPINFO, wpid, (caddr_t)&pl, sizeof(pl)) != -1);
+	ATF_REQUIRE((pl.pl_flags & PL_FLAG_SI) != 0);
+	ATF_REQUIRE(pl.pl_siginfo.si_signo == SIGTRAP);
+	ATF_REQUIRE(pl.pl_siginfo.si_code == TRAP_TRACE);
+
+	/* Continue the child process. */
+	ATF_REQUIRE(ptrace(PT_CONTINUE, fpid, (caddr_t)1, 0) == 0);
+
+	/* The last event should be for the child process's exit. */
+	wpid = waitpid(fpid, &status, 0);
+	ATF_REQUIRE(WIFEXITED(status));
+	ATF_REQUIRE(WEXITSTATUS(status) == 1);
+
+	wpid = wait(&status);
+	ATF_REQUIRE(wpid == -1);
+	ATF_REQUIRE(errno == ECHILD);
+}
+
 #if defined(HAVE_BREAKPOINT) && defined(SKIP_BREAK)
 static void *
 continue_thread(void *arg __unused)
@@ -3713,6 +3817,10 @@ ATF_TP_ADD_TCS(tp)
 	ATF_TP_ADD_TC(tp, ptrace__event_mask_sigkill_discard);
 	ATF_TP_ADD_TC(tp, ptrace__PT_ATTACH_with_SBDRY_thread);
 	ATF_TP_ADD_TC(tp, ptrace__PT_STEP_with_signal);
+#ifdef HAVE_BREAKPOINT
+	ATF_TP_ADD_TC(tp, ptrace__breakpoint_siginfo);
+#endif
+	ATF_TP_ADD_TC(tp, ptrace__step_siginfo);
 #if defined(HAVE_BREAKPOINT) && defined(SKIP_BREAK)
 	ATF_TP_ADD_TC(tp, ptrace__PT_CONTINUE_different_thread);
 #endif