Test the instruction address used by targets of an execute instruction.
When the target instruction calculates a relative address, the result is
relative to the target instruction, not the execute instruction.
Signed-off-by: Nina Schoetterl-Glausch <nsg@xxxxxxxxxxxxx>
---
TCG does the address calculation relative to the execute instruction.
s390x/Makefile | 1 +
s390x/ex.c | 92 ++++++++++++++++++++++++++++++++++++++++++++++++++
2 files changed, 93 insertions(+)
create mode 100644 s390x/ex.c
diff --git a/s390x/Makefile b/s390x/Makefile
index 97a61611..6cf8018b 100644
--- a/s390x/Makefile
+++ b/s390x/Makefile
@@ -39,6 +39,7 @@ tests += $(TEST_DIR)/panic-loop-extint.elf
tests += $(TEST_DIR)/panic-loop-pgm.elf
tests += $(TEST_DIR)/migration-sck.elf
tests += $(TEST_DIR)/exittime.elf
+tests += $(TEST_DIR)/ex.elf
pv-tests += $(TEST_DIR)/pv-diags.elf
diff --git a/s390x/ex.c b/s390x/ex.c
new file mode 100644
index 00000000..1bf4d8cd
--- /dev/null
+++ b/s390x/ex.c
@@ -0,0 +1,92 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright IBM Corp. 2023
+ *
+ * Test EXECUTE (RELATIVE LONG).
+ */
+
+#include <libcflat.h>
+
+static void test_basr(void)
+{
+ uint64_t ret_addr, after_ex;
+
+ report_prefix_push("BASR");
+ asm volatile ( ".pushsection .rodata\n"
+ "0: basr %[ret_addr],0\n"
+ " .popsection\n"
+
+ " larl %[after_ex],1f\n"
+ " exrl 0,0b\n"
+ "1:\n"
+ : [ret_addr] "=d" (ret_addr),
+ [after_ex] "=d" (after_ex)
+ );
+
+ report(ret_addr == after_ex, "return address after EX");
+ report_prefix_pop();
+}
+
+/*
+ * According to PoP (Branch-Address Generation), the address is relative to
+ * BRAS when it is the target of an execute-type instruction.
+ */
+static void test_bras(void)
+{
+ uint64_t after_target, ret_addr, after_ex, branch_addr;
+
+ report_prefix_push("BRAS");
+ asm volatile ( ".pushsection .text.ex_bras, \"x\"\n"
+ "0: bras %[ret_addr],1f\n"
+ " nopr %%r7\n"
+ "1: larl %[branch_addr],0\n"
+ " j 4f\n"
+ " .popsection\n"
+
+ " larl %[after_target],1b\n"
+ " larl %[after_ex],3f\n"
+ "2: exrl 0,0b\n"
+ "3: larl %[branch_addr],0\n"
+ "4:\n"
+
+ " .if (1b - 0b) != (3b - 2b)\n"
+ " .error \"right and wrong target must have same offset\"\n"
+ " .endif\n"
+ : [after_target] "=d" (after_target),
+ [ret_addr] "=d" (ret_addr),
+ [after_ex] "=d" (after_ex),
+ [branch_addr] "=d" (branch_addr)
+ );
+
+ report(after_target == branch_addr, "address calculated relative to BRAS");
+ report(ret_addr == after_ex, "return address after EX");
+ report_prefix_pop();
+}
+
+static void test_larl(void)
+{
+ uint64_t target, addr;
+
+ report_prefix_push("LARL");
+ asm volatile ( ".pushsection .rodata\n"
+ "0: larl %[addr],0\n"
+ " .popsection\n"
+
+ " larl %[target],0b\n"
+ " exrl 0,0b\n"
+ : [target] "=d" (target),
+ [addr] "=d" (addr)
+ );
+
+ report(target == addr, "address calculated relative to LARL");
+ report_prefix_pop();
+}
+
+int main(int argc, char **argv)
+{
+ test_basr();
+ test_bras();
+ test_larl();
+
+ return report_summary();
+}
base-commit: e3c5c3ef2524c58023073c0fadde2e8ae3c04ec6
--
2.36.1
