new file mode 100644
@@ -0,0 +1,62 @@
+/*
+ * Branch target identification, basic notskip cases.
+ */
+
+#include "bti-crt.inc.c"
+
+static void skip2_sigill(int sig, siginfo_t *info, ucontext_t *uc)
+{
+ uc->uc_mcontext.pc += 8;
+ uc->uc_mcontext.pstate = 1;
+}
+
+#define NOP "nop"
+#define BTI_N "hint #32"
+#define BTI_C "hint #34"
+#define BTI_J "hint #36"
+#define BTI_JC "hint #38"
+
+#define BTYPE_1(DEST) \
+ asm("mov %0,#1; adr x16, 1f; br x16; 1: " DEST "; mov %0,#0" \
+ : "=r"(skipped) : : "x16")
+
+#define BTYPE_2(DEST) \
+ asm("mov %0,#1; adr x16, 1f; blr x16; 1: " DEST "; mov %0,#0" \
+ : "=r"(skipped) : : "x16", "x30")
+
+#define BTYPE_3(DEST) \
+ asm("mov %0,#1; adr x15, 1f; br x15; 1: " DEST "; mov %0,#0" \
+ : "=r"(skipped) : : "x15")
+
+#define TEST(WHICH, DEST, EXPECT) \
+ do { WHICH(DEST); fail += skipped ^ EXPECT; } while (0)
+
+
+int main()
+{
+ int fail = 0;
+ int skipped;
+
+ /* Signal-like with SA_SIGINFO. */
+ signal_info(SIGILL, skip2_sigill);
+
+ TEST(BTYPE_1, NOP, 1);
+ TEST(BTYPE_1, BTI_N, 1);
+ TEST(BTYPE_1, BTI_C, 0);
+ TEST(BTYPE_1, BTI_J, 0);
+ TEST(BTYPE_1, BTI_JC, 0);
+
+ TEST(BTYPE_2, NOP, 1);
+ TEST(BTYPE_2, BTI_N, 1);
+ TEST(BTYPE_2, BTI_C, 0);
+ TEST(BTYPE_2, BTI_J, 1);
+ TEST(BTYPE_2, BTI_JC, 0);
+
+ TEST(BTYPE_3, NOP, 1);
+ TEST(BTYPE_3, BTI_N, 1);
+ TEST(BTYPE_3, BTI_C, 1);
+ TEST(BTYPE_3, BTI_J, 0);
+ TEST(BTYPE_3, BTI_JC, 0);
+
+ return fail;
+}
new file mode 100644
@@ -0,0 +1,69 @@
+/*
+ * Minimal user-environment for testing BTI.
+ *
+ * Normal libc is not built with BTI support enabled, and so could
+ * generate a BTI TRAP before ever reaching main.
+ */
+
+#include <stdlib.h>
+#include <signal.h>
+#include <ucontext.h>
+#include <asm/unistd.h>
+
+int main(void);
+
+void _start(void)
+{
+ exit(main());
+}
+
+void exit(int ret)
+{
+ register int x0 __asm__("x0") = ret;
+ register int x8 __asm__("x8") = __NR_exit;
+
+ asm volatile("svc #0" : : "r"(x0), "r"(x8));
+ __builtin_unreachable();
+}
+
+/*
+ * Irritatingly, the user API struct sigaction does not match the
+ * kernel API struct sigaction. So for simplicity, isolate the
+ * kernel ABI here, and make this act like signal.
+ */
+void signal_info(int sig, void (*fn)(int, siginfo_t *, ucontext_t *))
+{
+ struct kernel_sigaction {
+ void (*handler)(int, siginfo_t *, ucontext_t *);
+ unsigned long flags;
+ unsigned long restorer;
+ unsigned long mask;
+ } sa = { fn, SA_SIGINFO, 0, 0 };
+
+ register int x0 __asm__("x0") = sig;
+ register void *x1 __asm__("x1") = &sa;
+ register void *x2 __asm__("x2") = 0;
+ register int x3 __asm__("x3") = sizeof(unsigned long);
+ register int x8 __asm__("x8") = __NR_rt_sigaction;
+
+ asm volatile("svc #0"
+ : : "r"(x0), "r"(x1), "r"(x2), "r"(x3), "r"(x8) : "memory");
+}
+
+/*
+ * Create the PT_NOTE that will enable BTI in the page tables.
+ * This will be created by the compiler with -mbranch-protection=standard,
+ * but as of 2019-03-29, this is has not been committed to gcc mainline.
+ * This will probably be in GCC10.
+ */
+asm(".section .note.gnu.property,\"a\"\n\
+ .align 3\n\
+ .long 4\n\
+ .long 16\n\
+ .long 5\n\
+ .string \"GNU\"\n\
+ .long 0xc0000000\n\
+ .long 4\n\
+ .long 1\n\
+ .align 3\n\
+ .previous");
@@ -18,4 +18,7 @@ run-fcvt: fcvt
AARCH64_TESTS += pauth-1
run-pauth-%: QEMU += -cpu max
+AARCH64_TESTS += bti-1
+bti-1: LDFLAGS += -nostartfiles -nodefaultlibs -nostdlib
+
TESTS:=$(AARCH64_TESTS)
Signed-off-by: Richard Henderson <richard.henderson@linaro.org> --- tests/tcg/aarch64/bti-1.c | 62 +++++++++++++++++++++++++++ tests/tcg/aarch64/bti-crt.inc.c | 69 +++++++++++++++++++++++++++++++ tests/tcg/aarch64/Makefile.target | 3 ++ 3 files changed, 134 insertions(+) create mode 100644 tests/tcg/aarch64/bti-1.c create mode 100644 tests/tcg/aarch64/bti-crt.inc.c -- 2.17.1