lkl: remove string functions duplicate implementation

arch/lkl/Kconfig

@@ -182,3 +182,24 @@ config BUILTIN_CMDLINE
 	  image and used at boot time. The command line provided to
 	  lkl_start_kernel is appended to this string to form the full
 	  command line.
+
+config LKL_HOST_MEMCPY
+	bool "Host provides memcpy"
+	default n
+	help
+	  This options should be set (in tools/lkl/Makefile.autoconf)
+	  if the host provides a memcpy implementation.
+
+config LKL_HOST_MEMSET
+	bool "Host provides memset"
+	default n
+	help
+	  This options should be set (in tools/lkl/Makefile.autoconf)
+	  if the host provides a memset implementation.
+
+config LKL_HOST_MEMMOVE
+	bool "Host provides memmove"
+	default n
+	help
+	  This options should be set (in tools/lkl/Makefile.autoconf)
+	  if the host provides a memmove implementation.

arch/lkl/include/asm/string.h

@@ -7,70 +7,35 @@
 
 /* use __mem* names to avoid conflict with KASAN's mem* functions. */
 
+#ifdef CONFIG_LKL_HOST_MEMCPY
 #define __HAVE_ARCH_MEMCPY
 extern void *memcpy(void *dest, const void *src, size_t count);
 static inline void *__memcpy(void *dest, const void *src, size_t count)
 {
-	char *tmp = dest;
-	const char *s = src;
-
-	if (lkl_ops->memcpy)
-		return lkl_ops->memcpy(dest, src, count);
-
-	/* from lib/string.c */
-
-	while (count--)
-		*tmp++ = *s++;
-	return dest;
+	return lkl_ops->memcpy(dest, src, count);
 }
+#define memcpy(dst, src, len) __memcpy(dst, src, len)
+#endif
 
+#ifdef CONFIG_LKL_HOST_MEMSET
 #define __HAVE_ARCH_MEMSET
 extern void *memset(void *s, int c, size_t count);
 static inline void *__memset(void *s, int c, size_t count)
 {
-	char *xs = s;
-
-	if (lkl_ops->memset)
-		return lkl_ops->memset(s, c, count);
-
-	/* from lib/string.c */
-
-	while (count--)
-		*xs++ = c;
-	return s;
+	return lkl_ops->memset(s, c, count);
 }
+#define memset(s, c, n) __memset(s, c, n)
+#endif
 
+#ifdef CONFIG_LKL_HOST_MEMSET
 #define __HAVE_ARCH_MEMMOVE
 extern void *memmove(void *dest, const void *src, size_t count);
 static inline void *__memmove(void *dest, const void *src, size_t count)
 {
-	char *tmp;
-	const char *s;
-
-	if (lkl_ops->memmove)
-		return lkl_ops->memmove(dest, src, count);
-
-	/* from lib/string.c */
-
-	if (dest <= src) {
-		tmp = dest;
-		s = src;
-		while (count--)
-			*tmp++ = *s++;
-	} else {
-		tmp = dest;
-		tmp += count;
-		s = src;
-		s += count;
-		while (count--)
-			*--tmp = *--s;
-	}
-	return dest;
+	return lkl_ops->memmove(dest, src, count);
 }
-
-#define memcpy(dst, src, len) __memcpy(dst, src, len)
-#define memset(s, c, n) __memset(s, c, n)
 #define memmove(dst, src, len) __memmove(dst, src, len)
+#endif
 
 #if defined(CONFIG_KASAN)
 

arch/lkl/kernel/init.c

@@ -4,6 +4,13 @@
 
 int lkl_init(struct lkl_host_operations *ops)
 {
+	if ((IS_ENABLED(CONFIG_LKL_HOST_MEMCPY) && !ops->memcpy)
+	 || (IS_ENABLED(CONFIG_LKL_HOST_MEMSET) && !ops->memset)
+	 || (IS_ENABLED(CONFIG_LKL_HOST_MEMMOVE) && !ops->memmove)) {
+		lkl_printf("unexpected NULL lkl_host_ops member\n");
+		return -1;
+	}
+
 	lkl_ops = ops;
 
 	return kasan_init();

arch/lkl/lib/string.c

@@ -14,22 +14,28 @@
 #undef memset
 #undef memmove
 
+#ifdef __HAVE_ARCH_MEMCPY
 __visible void *memcpy(void *dest, const void *src, size_t count)
 {
 	return __memcpy(dest, src, count);
 }
 EXPORT_SYMBOL(memcpy);
+#endif
 
+#ifdef __HAVE_ARCH_MEMSET
 __visible void *memset(void *s, int c, size_t count)
 {
 	return __memset(s, c, count);
 }
 EXPORT_SYMBOL(memset);
+#endif
 
+#ifdef __HAVE_ARCH_MEMMOVE
 __visible void *memmove(void *dest, const void *src, size_t count)
 {
 	return __memmove(dest, src, count);
 }
 EXPORT_SYMBOL(memmove);
+#endif
 
 #endif

tools/lkl/Makefile.autoconf

@@ -89,6 +89,9 @@ define posix_host
   $(if $(filter $(1),elf32-i386),$(call set_autoconf_var,I386,y))
   $(if $(strip $(call find_include,jsmn.h)),$(call set_autoconf_var,JSMN,y))
   $(if $(filter %,$(zpoline)),$(call zpoline_conf,$(zpoline)))
+  $(call set_kernel_config,LKL_HOST_MEMCPY,y)
+  $(call set_kernel_config,LKL_HOST_MEMSET,y)
+  $(call set_kernel_config,LKL_HOST_MEMMOVE,y)
 endef
 
 define nt64_host

tools/lkl/tests/boot.c

@@ -780,7 +780,10 @@ int main(int argc, const char **argv)
 
 	lkl_host_ops.print = lkl_test_log;
 
-	lkl_init(&lkl_host_ops);
+	if (lkl_init(&lkl_host_ops) < 0) {
+		printf("%s\n", lkl_test_get_log());
+		return 1;
+	}
 
 	ret = lkl_test_run(tests, sizeof(tests)/sizeof(struct lkl_test),
 			"boot");

tools/lkl/tests/disk-vfio-pci.c

@@ -109,7 +109,10 @@ int main(int argc, const char **argv)
 
 	lkl_host_ops.print = lkl_test_log;
 
-	lkl_init(&lkl_host_ops);
+	if (lkl_init(&lkl_host_ops) < 0) {
+		printf("%s\n", lkl_test_get_log());
+		return 1;
+	}
 
 	ret = lkl_test_run(tests, sizeof(tests) / sizeof(struct lkl_test),
 			"disk-vfio-pci %s", cla.fstype);

tools/lkl/tests/disk.c

@@ -189,7 +189,10 @@ int main(int argc, const char **argv)
 
 	lkl_host_ops.print = lkl_test_log;
 
-	lkl_init(&lkl_host_ops);
+	if (lkl_init(&lkl_host_ops) < 0) {
+		printf("%s\n", lkl_test_get_log());
+		return 1;
+	}
 
 	ret = lkl_test_run(tests, sizeof(tests)/sizeof(struct lkl_test),
 			"disk %s", cla.fstype);