RISC-V: mm: Add tests for RISC-V mm

Add tests that enforce mmap hint address behavior. mmap should default
to sv48. mmap will provide an address at the highest address space that
can fit into the hint address, unless the hint address is less than sv39
and not 0, then it will return a sv39 address.

These tests are split into two files: mmap_default.c and mmap_bottomup.c
because a new process must be exec'd in order to change the mmap layout.
The run_mmap.sh script sets the stack to be unlimited for the
mmap_bottomup.c test which triggers a bottomup layout.

Signed-off-by: Charlie Jenkins <charlie@rivosinc.com>
Link: https://lore.kernel.org/r/20230809232218.849726-3-charlie@rivosinc.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>

6 files changed, 163 insertions, 0 deletions

diff --git a/tools/testing/selftests/riscv/mm/.gitignore b/tools/testing/selftests/riscv/mm/.gitignore
new file mode 100644
index 000000000000..5c2c57cb950c
--- /dev/null
+++ b/tools/testing/selftests/riscv/mm/.gitignore
@@ -0,0 +1,2 @@
+mmap_bottomup
+mmap_default
diff --git a/tools/testing/selftests/riscv/mm/Makefile b/tools/testing/selftests/riscv/mm/Makefile
new file mode 100644
index 000000000000..11e0f0568923
--- /dev/null
+++ b/tools/testing/selftests/riscv/mm/Makefile
@@ -0,0 +1,15 @@
+# SPDX-License-Identifier: GPL-2.0
+# Copyright (C) 2021 ARM Limited
+# Originally tools/testing/arm64/abi/Makefile
+
+# Additional include paths needed by kselftest.h and local headers
+CFLAGS += -D_GNU_SOURCE -std=gnu99 -I.
+
+TEST_GEN_FILES := testcases/mmap_default testcases/mmap_bottomup
+
+TEST_PROGS := testcases/run_mmap.sh
+
+include ../../lib.mk
+
+$(OUTPUT)/mm: testcases/mmap_default.c testcases/mmap_bottomup.c testcases/mmap_tests.h
+	$(CC) -o$@ $(CFLAGS) $(LDFLAGS) $^
diff --git a/tools/testing/selftests/riscv/mm/testcases/mmap_bottomup.c b/tools/testing/selftests/riscv/mm/testcases/mmap_bottomup.c
new file mode 100644
index 000000000000..b29379f7e478
--- /dev/null
+++ b/tools/testing/selftests/riscv/mm/testcases/mmap_bottomup.c
@@ -0,0 +1,35 @@
+// SPDX-License-Identifier: GPL-2.0-only
+#include <sys/mman.h>
+#include <testcases/mmap_test.h>
+
+#include "../../kselftest_harness.h"
+
+TEST(infinite_rlimit)
+{
+// Only works on 64 bit
+#if __riscv_xlen == 64
+	struct addresses mmap_addresses;
+
+	EXPECT_EQ(BOTTOM_UP, memory_layout());
+
+	do_mmaps(&mmap_addresses);
+
+	EXPECT_NE(MAP_FAILED, mmap_addresses.no_hint);
+	EXPECT_NE(MAP_FAILED, mmap_addresses.on_37_addr);
+	EXPECT_NE(MAP_FAILED, mmap_addresses.on_38_addr);
+	EXPECT_NE(MAP_FAILED, mmap_addresses.on_46_addr);
+	EXPECT_NE(MAP_FAILED, mmap_addresses.on_47_addr);
+	EXPECT_NE(MAP_FAILED, mmap_addresses.on_55_addr);
+	EXPECT_NE(MAP_FAILED, mmap_addresses.on_56_addr);
+
+	EXPECT_GT(1UL << 47, (unsigned long)mmap_addresses.no_hint);
+	EXPECT_GT(1UL << 38, (unsigned long)mmap_addresses.on_37_addr);
+	EXPECT_GT(1UL << 38, (unsigned long)mmap_addresses.on_38_addr);
+	EXPECT_GT(1UL << 38, (unsigned long)mmap_addresses.on_46_addr);
+	EXPECT_GT(1UL << 47, (unsigned long)mmap_addresses.on_47_addr);
+	EXPECT_GT(1UL << 47, (unsigned long)mmap_addresses.on_55_addr);
+	EXPECT_GT(1UL << 56, (unsigned long)mmap_addresses.on_56_addr);
+#endif
+}
+
+TEST_HARNESS_MAIN
diff --git a/tools/testing/selftests/riscv/mm/testcases/mmap_default.c b/tools/testing/selftests/riscv/mm/testcases/mmap_default.c
new file mode 100644
index 000000000000..d1accb91b726
--- /dev/null
+++ b/tools/testing/selftests/riscv/mm/testcases/mmap_default.c
@@ -0,0 +1,35 @@
+// SPDX-License-Identifier: GPL-2.0-only
+#include <sys/mman.h>
+#include <testcases/mmap_test.h>
+
+#include "../../kselftest_harness.h"
+
+TEST(default_rlimit)
+{
+// Only works on 64 bit
+#if __riscv_xlen == 64
+	struct addresses mmap_addresses;
+
+	EXPECT_EQ(TOP_DOWN, memory_layout());
+
+	do_mmaps(&mmap_addresses);
+
+	EXPECT_NE(MAP_FAILED, mmap_addresses.no_hint);
+	EXPECT_NE(MAP_FAILED, mmap_addresses.on_37_addr);
+	EXPECT_NE(MAP_FAILED, mmap_addresses.on_38_addr);
+	EXPECT_NE(MAP_FAILED, mmap_addresses.on_46_addr);
+	EXPECT_NE(MAP_FAILED, mmap_addresses.on_47_addr);
+	EXPECT_NE(MAP_FAILED, mmap_addresses.on_55_addr);
+	EXPECT_NE(MAP_FAILED, mmap_addresses.on_56_addr);
+
+	EXPECT_GT(1UL << 47, (unsigned long)mmap_addresses.no_hint);
+	EXPECT_GT(1UL << 38, (unsigned long)mmap_addresses.on_37_addr);
+	EXPECT_GT(1UL << 38, (unsigned long)mmap_addresses.on_38_addr);
+	EXPECT_GT(1UL << 38, (unsigned long)mmap_addresses.on_46_addr);
+	EXPECT_GT(1UL << 47, (unsigned long)mmap_addresses.on_47_addr);
+	EXPECT_GT(1UL << 47, (unsigned long)mmap_addresses.on_55_addr);
+	EXPECT_GT(1UL << 56, (unsigned long)mmap_addresses.on_56_addr);
+#endif
+}
+
+TEST_HARNESS_MAIN
diff --git a/tools/testing/selftests/riscv/mm/testcases/mmap_test.h b/tools/testing/selftests/riscv/mm/testcases/mmap_test.h
new file mode 100644
index 000000000000..9b8434f62f57
--- /dev/null
+++ b/tools/testing/selftests/riscv/mm/testcases/mmap_test.h
@@ -0,0 +1,64 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+#ifndef _TESTCASES_MMAP_TEST_H
+#define _TESTCASES_MMAP_TEST_H
+#include <sys/mman.h>
+#include <sys/resource.h>
+#include <stddef.h>
+
+#define TOP_DOWN 0
+#define BOTTOM_UP 1
+
+struct addresses {
+	int *no_hint;
+	int *on_37_addr;
+	int *on_38_addr;
+	int *on_46_addr;
+	int *on_47_addr;
+	int *on_55_addr;
+	int *on_56_addr;
+};
+
+static inline void do_mmaps(struct addresses *mmap_addresses)
+{
+	/*
+	 * Place all of the hint addresses on the boundaries of mmap
+	 * sv39, sv48, sv57
+	 * User addresses end at 1<<38, 1<<47, 1<<56 respectively
+	 */
+	void *on_37_bits = (void *)(1UL << 37);
+	void *on_38_bits = (void *)(1UL << 38);
+	void *on_46_bits = (void *)(1UL << 46);
+	void *on_47_bits = (void *)(1UL << 47);
+	void *on_55_bits = (void *)(1UL << 55);
+	void *on_56_bits = (void *)(1UL << 56);
+
+	int prot = PROT_READ | PROT_WRITE;
+	int flags = MAP_PRIVATE | MAP_ANONYMOUS;
+
+	mmap_addresses->no_hint =
+		mmap(NULL, 5 * sizeof(int), prot, flags, 0, 0);
+	mmap_addresses->on_37_addr =
+		mmap(on_37_bits, 5 * sizeof(int), prot, flags, 0, 0);
+	mmap_addresses->on_38_addr =
+		mmap(on_38_bits, 5 * sizeof(int), prot, flags, 0, 0);
+	mmap_addresses->on_46_addr =
+		mmap(on_46_bits, 5 * sizeof(int), prot, flags, 0, 0);
+	mmap_addresses->on_47_addr =
+		mmap(on_47_bits, 5 * sizeof(int), prot, flags, 0, 0);
+	mmap_addresses->on_55_addr =
+		mmap(on_55_bits, 5 * sizeof(int), prot, flags, 0, 0);
+	mmap_addresses->on_56_addr =
+		mmap(on_56_bits, 5 * sizeof(int), prot, flags, 0, 0);
+}
+
+static inline int memory_layout(void)
+{
+	int prot = PROT_READ | PROT_WRITE;
+	int flags = MAP_PRIVATE | MAP_ANONYMOUS;
+
+	void *value1 = mmap(NULL, sizeof(int), prot, flags, 0, 0);
+	void *value2 = mmap(NULL, sizeof(int), prot, flags, 0, 0);
+
+	return value2 > value1;
+}
+#endif /* _TESTCASES_MMAP_TEST_H */
diff --git a/tools/testing/selftests/riscv/mm/testcases/run_mmap.sh b/tools/testing/selftests/riscv/mm/testcases/run_mmap.sh
new file mode 100755
index 000000000000..ca5ad7c48bad
--- /dev/null
+++ b/tools/testing/selftests/riscv/mm/testcases/run_mmap.sh
@@ -0,0 +1,12 @@
+#!/bin/sh
+# SPDX-License-Identifier: GPL-2.0
+
+original_stack_limit=$(ulimit -s)
+
+./mmap_default
+
+# Force mmap_bottomup to be ran with bottomup memory due to
+# the unlimited stack
+ulimit -s unlimited
+./mmap_bottomup
+ulimit -s $original_stack_limit