diff mbox series

[2/2] kselftest/arm64: Run BTI selftests on systems without BTI

Message ID 20230110-arm64-bti-selftest-skip-v1-2-143ecdc84567@kernel.org (mailing list archive)
State Accepted
Commit 1c3b614548b50227c5950258831b130d832703b5
Headers show
Series kselftest/arm64: Improvements to BTI tests on non-BTI systems | expand

Commit Message

Mark Brown Jan. 10, 2023, 8:49 p.m. UTC
The BTI selftests are built both with and without BTI support, validating
both the generation of BTI signals as expected for binaries without BTI
support. Both versions of the binary currently skip all their tests when
the system does not support BTI, however this is excessive since we do have
a defined ABI for how the programs should function in this case (especially
for the non-BTI binary). Update the test program to run all the tests
unconditionally, adding a runtime adjustment of the expected results on
systems that don't support BTI where we currently handle the build time
case.

The tests all use HINT space instructions, BTI itself is a HINT as is
are the PAC instructions that function as landing pads, so nothing in the
tests depends on support for BTI in the kernel or hardware.

Signed-off-by: Mark Brown <broonie@kernel.org>
---
 tools/testing/selftests/arm64/bti/test.c | 25 ++++++++++---------------
 1 file changed, 10 insertions(+), 15 deletions(-)
diff mbox series

Patch

diff --git a/tools/testing/selftests/arm64/bti/test.c b/tools/testing/selftests/arm64/bti/test.c
index 4b6dda987c58..2cd8dcee5aec 100644
--- a/tools/testing/selftests/arm64/bti/test.c
+++ b/tools/testing/selftests/arm64/bti/test.c
@@ -6,6 +6,7 @@ 
 
 #include "system.h"
 
+#include <stdbool.h>
 #include <stddef.h>
 #include <linux/errno.h>
 #include <linux/auxvec.h>
@@ -101,7 +102,8 @@  static void handler(int n, siginfo_t *si __always_unused,
 	uc->uc_mcontext.pstate &= ~PSR_BTYPE_MASK;
 }
 
-static int skip_all;
+/* Does the system have BTI? */
+static bool have_bti;
 
 static void __do_test(void (*trampoline)(void (*)(void)),
 		      void (*fn)(void),
@@ -109,19 +111,11 @@  static void __do_test(void (*trampoline)(void (*)(void)),
 		      const char *name,
 		      int expect_sigill)
 {
-	if (skip_all) {
-		test_skipped++;
-		putstr("ok ");
-		putnum(test_num++);
-		putstr(" ");
-		puttestname(name, trampoline_name);
-		putstr(" # SKIP\n");
-
-		return;
-	}
-
-	/* Branch Target exceptions should only happen in BTI binaries: */
-	if (!BTI)
+	/*
+	 * Branch Target exceptions should only happen for BTI
+	 * binaries running on a system with BTI:
+	 */
+	if (!BTI || !have_bti)
 		expect_sigill = 0;
 
 	sigill_expected = expect_sigill;
@@ -199,9 +193,10 @@  void start(int *argcp)
 		putstr("# HWCAP2_BTI present\n");
 		if (!(hwcap & HWCAP_PACA))
 			putstr("# Bad hardware?  Expect problems.\n");
+		have_bti = true;
 	} else {
 		putstr("# HWCAP2_BTI not present\n");
-		skip_all = 1;
+		have_bti = false;
 	}
 
 	putstr("# Test binary");