target/riscv: Make translator stop before the end of a page

Right now the translator stops right *after* the end of a page, which
breaks reporting of fault locations when the last instruction of a
multi-insn translation block crosses a page boundary.

Resolves: https://gitlab.com/qemu-project/qemu/-/issues/1155
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Acked-by: Ilya Leoshkevich <iii@linux.ibm.com>
Tested-by: Ilya Leoshkevich <iii@linux.ibm.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

2 files changed, 80 insertions, 0 deletions

diff --git a/tests/tcg/riscv64/Makefile.target b/tests/tcg/riscv64/Makefile.target
index d41bf6d..b5b89df 100644
--- a/tests/tcg/riscv64/Makefile.target
+++ b/tests/tcg/riscv64/Makefile.target
@@ -3,3 +3,4 @@
 
 VPATH += $(SRC_PATH)/tests/tcg/riscv64
 TESTS += test-div
+TESTS += noexec
diff --git a/tests/tcg/riscv64/noexec.c b/tests/tcg/riscv64/noexec.c
new file mode 100644
index 0000000..86f64b2
--- /dev/null
+++ b/tests/tcg/riscv64/noexec.c
@@ -0,0 +1,79 @@
+#include "../multiarch/noexec.c.inc"
+
+static void *arch_mcontext_pc(const mcontext_t *ctx)
+{
+    return (void *)ctx->__gregs[REG_PC];
+}
+
+static int arch_mcontext_arg(const mcontext_t *ctx)
+{
+    return ctx->__gregs[REG_A0];
+}
+
+static void arch_flush(void *p, int len)
+{
+    __builtin___clear_cache(p, p + len);
+}
+
+extern char noexec_1[];
+extern char noexec_2[];
+extern char noexec_end[];
+
+asm(".option push\n"
+    ".option norvc\n"
+    "noexec_1:\n"
+    "   li a0,1\n"       /* a0 is 0 on entry, set 1. */
+    "noexec_2:\n"
+    "   li a0,2\n"      /* a0 is 0/1; set 2. */
+    "   ret\n"
+    "noexec_end:\n"
+    ".option pop");
+
+int main(void)
+{
+    struct noexec_test noexec_tests[] = {
+        {
+            .name = "fallthrough",
+            .test_code = noexec_1,
+            .test_len = noexec_end - noexec_1,
+            .page_ofs = noexec_1 - noexec_2,
+            .entry_ofs = noexec_1 - noexec_2,
+            .expected_si_ofs = 0,
+            .expected_pc_ofs = 0,
+            .expected_arg = 1,
+        },
+        {
+            .name = "jump",
+            .test_code = noexec_1,
+            .test_len = noexec_end - noexec_1,
+            .page_ofs = noexec_1 - noexec_2,
+            .entry_ofs = 0,
+            .expected_si_ofs = 0,
+            .expected_pc_ofs = 0,
+            .expected_arg = 0,
+        },
+        {
+            .name = "fallthrough [cross]",
+            .test_code = noexec_1,
+            .test_len = noexec_end - noexec_1,
+            .page_ofs = noexec_1 - noexec_2 - 2,
+            .entry_ofs = noexec_1 - noexec_2 - 2,
+            .expected_si_ofs = 0,
+            .expected_pc_ofs = -2,
+            .expected_arg = 1,
+        },
+        {
+            .name = "jump [cross]",
+            .test_code = noexec_1,
+            .test_len = noexec_end - noexec_1,
+            .page_ofs = noexec_1 - noexec_2 - 2,
+            .entry_ofs = -2,
+            .expected_si_ofs = 0,
+            .expected_pc_ofs = -2,
+            .expected_arg = 0,
+        },
+    };
+
+    return test_noexec(noexec_tests,
+                       sizeof(noexec_tests) / sizeof(noexec_tests[0]));
+}