ARM: kprobes: Prevent known test failures stopping other tests running

Due to a long-standing issue with Thumb symbol lookup [1] the jprobes
tests fail when built into a kernel compiled as Thumb mode. (They work
fine for ARM mode kernels or for Thumb when built as a loadable module.)

Rather than have this problem terminate testing prematurely lets instead
emit an error message and carry on with the main kprobes tests, delaying
the final failure report until the end.

[1] http://lists.infradead.org/pipermail/linux-arm-kernel/2011-August/063026.htmlSigned-off-by: Jon Medhurst <tixy@linaro.org>

arch/arm/kernel/kprobes-test.c

@@ -225,6 +225,7 @@ static int pre_handler_called;
 static int post_handler_called;
 static int jprobe_func_called;
 static int kretprobe_handler_called;
+static int tests_failed;
 
 #define FUNC_ARG1 0x12345678
 #define FUNC_ARG2 0xabcdef
@@ -461,6 +462,13 @@ static int run_api_tests(long (*func)(long, long))
 
 	pr_info("    jprobe\n");
 	ret = test_jprobe(func);
+#if defined(CONFIG_THUMB2_KERNEL) && !defined(MODULE)
+	if (ret == -EINVAL) {
+		pr_err("FAIL: Known longtime bug with jprobe on Thumb kernels\n");
+		tests_failed = ret;
+		ret = 0;
+	}
+#endif
 	if (ret < 0)
 		return ret;
 
@@ -1671,6 +1679,8 @@ static int __init run_all_tests(void)
 #endif
 
 out:
+	if (ret == 0)
+		ret = tests_failed;
 	if (ret == 0)
 		pr_info("Finished kprobe tests OK\n");
 	else