selftests/powerpc/copyloops: Add memmove_64 test

While debugging an issue, we wanted to check whether the arch specific
kernel memmove implementation is correct.
This selftest could help test that.

Suggested-by: Aneesh Kumar K.V <[e-mail]>
Suggested-by: Vaibhav Jain <[e-mail]>
Signed-off-by: Ritesh Harjani <[e-mail]>
Signed-off-by: Michael Ellerman <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]

tools/testing/selftests/powerpc/copyloops/.gitignore

···
 copyuser_64_exc_t1
 copyuser_64_exc_t2
 copy_mc_64
+memmove_64

tools/testing/selftests/powerpc/copyloops/Makefile

···
 		copyuser_p7_t0 copyuser_p7_t1 \
 		memcpy_64_t0 memcpy_64_t1 memcpy_64_t2 \
 		memcpy_p7_t0 memcpy_p7_t1 copy_mc_64 \
-		copyuser_64_exc_t0 copyuser_64_exc_t1 copyuser_64_exc_t2
+		copyuser_64_exc_t0 copyuser_64_exc_t1 copyuser_64_exc_t2 \
+		memmove_64
 
 EXTRA_SOURCES := validate.c ../harness.c stubs.S
 
···
 	$(CC) $(CPPFLAGS) $(CFLAGS) \
 		-D COPY_LOOP=test___copy_tofrom_user_base \
 		-D SELFTEST_CASE=$(subst copyuser_64_exc_t,,$(notdir $@)) \
+		-o $@ $^
+
+$(OUTPUT)/memmove_64: mem_64.S memcpy_64.S memmove_validate.c ../harness.c \
+		memcpy_stubs.S
+	$(CC) $(CPPFLAGS) $(CFLAGS) \
+		-D TEST_MEMMOVE=test_memmove \
 		-o $@ $^

tools/testing/selftests/powerpc/copyloops/asm/ppc_asm.h

···
 #define _GLOBAL(A) FUNC_START(test_ ## A)
 #define _GLOBAL_TOC(A) _GLOBAL(A)
 #define _GLOBAL_TOC_KASAN(A) _GLOBAL(A)
+#define _GLOBAL_KASAN(A) _GLOBAL(A)
 
 #define PPC_MTOCRF(A, B)	mtocrf A, B
 

tools/testing/selftests/powerpc/copyloops/memcpy_stubs.S

···
+/* SPDX-License-Identifier: GPL-2.0 */
+#include <asm/ppc_asm.h>
+
+FUNC_START(memcpy)
+	b test_memcpy
+
+FUNC_START(backwards_memcpy)
+	b test_backwards_memcpy

tools/testing/selftests/powerpc/copyloops/memmove_validate.c

···
+// SPDX-License-Identifier: GPL-2.0
+#include <malloc.h>
+#include <stdlib.h>
+#include <string.h>
+#include <assert.h>
+#include "utils.h"
+
+void *TEST_MEMMOVE(const void *s1, const void *s2, size_t n);
+
+#define BUF_LEN 65536
+#define MAX_OFFSET 512
+
+size_t max(size_t a, size_t b)
+{
+	if (a >= b)
+		return a;
+	return b;
+}
+
+static int testcase_run(void)
+{
+	size_t i, src_off, dst_off, len;
+
+	char *usermap = memalign(BUF_LEN, BUF_LEN);
+	char *kernelmap = memalign(BUF_LEN, BUF_LEN);
+
+	assert(usermap != NULL);
+	assert(kernelmap != NULL);
+
+	memset(usermap, 0, BUF_LEN);
+	memset(kernelmap, 0, BUF_LEN);
+
+	for (i = 0; i < BUF_LEN; i++) {
+		usermap[i] = i & 0xff;
+		kernelmap[i] = i & 0xff;
+	}
+
+	for (src_off = 0; src_off < MAX_OFFSET; src_off++) {
+		for (dst_off = 0; dst_off < MAX_OFFSET; dst_off++) {
+			for (len = 1; len < MAX_OFFSET - max(src_off, dst_off); len++) {
+
+				memmove(usermap + dst_off, usermap + src_off, len);
+				TEST_MEMMOVE(kernelmap + dst_off, kernelmap + src_off, len);
+				if (memcmp(usermap, kernelmap, MAX_OFFSET) != 0) {
+					printf("memmove failed at %ld %ld %ld\n",
+							src_off, dst_off, len);
+					abort();
+				}
+			}
+		}
+	}
+	return 0;
+}
+
+int main(void)
+{
+	return test_harness(testcase_run, "memmove");
+}