tools: Adopt memdup() from tools/perf, moving it to tools/lib/string.c

That will contain more string functions with counterparts, sometimes
verbatim copies, in the kernel.

Acked-by: Wang Nan <[e-mail]>
Cc: Adrian Hunter <[e-mail]>
Cc: Alexey Dobriyan <[e-mail]>
Cc: David Ahern <[e-mail]>
Cc: Jiri Olsa <[e-mail]>
Cc: Namhyung Kim <[e-mail]>
Link: http://lkml.kernel.org/n/[e-mail]
Signed-off-by: Arnaldo Carvalho de Melo <[e-mail]>

tools/include/linux/string.h

···
+#ifndef _TOOLS_LINUX_STRING_H_
+#define _TOOLS_LINUX_STRING_H_
+
+
+#include <linux/types.h>	/* for size_t */
+
+void *memdup(const void *src, size_t len);
+
+#endif /* _LINUX_STRING_H_ */

tools/lib/string.c

···
+#include <stdlib.h>
+#include <string.h>
+#include <linux/string.h>
+
+/**
+ * memdup - duplicate region of memory
+ *
+ * @src: memory region to duplicate
+ * @len: memory region length
+ */
+void *memdup(const void *src, size_t len)
+{
+	void *p = malloc(len);
+
+	if (p)
+		memcpy(p, src, len);
+
+	return p;
+}

tools/perf/MANIFEST

···
 tools/lib/bpf
 tools/lib/hweight.c
 tools/lib/rbtree.c
+tools/lib/string.c
 tools/lib/symbol/kallsyms.c
 tools/lib/symbol/kallsyms.h
 tools/lib/util/find_next_bit.c
···
 tools/include/linux/poison.h
 tools/include/linux/rbtree.h
 tools/include/linux/rbtree_augmented.h
+tools/include/linux/string.h
 tools/include/linux/types.h
 tools/include/linux/err.h
 include/asm-generic/bitops/arch_hweight.h

tools/perf/util/Build

···
 libperf-y += perf_regs.o
 libperf-y += path.o
 libperf-y += rbtree.o
+libperf-y += libstring.o
 libperf-y += bitmap.o
 libperf-y += hweight.o
 libperf-y += run-command.o
···
 
 CFLAGS_find_next_bit.o += -Wno-unused-parameter -DETC_PERFCONFIG="BUILD_STR($(ETC_PERFCONFIG_SQ))"
 CFLAGS_rbtree.o        += -Wno-unused-parameter -DETC_PERFCONFIG="BUILD_STR($(ETC_PERFCONFIG_SQ))"
+CFLAGS_libstring.o     += -Wno-unused-parameter -DETC_PERFCONFIG="BUILD_STR($(ETC_PERFCONFIG_SQ))"
 CFLAGS_hweight.o       += -Wno-unused-parameter -DETC_PERFCONFIG="BUILD_STR($(ETC_PERFCONFIG_SQ))"
 CFLAGS_parse-events.o  += -Wno-redundant-decls
 
···
 	$(call if_changed_dep,cc_o_c)
 
 $(OUTPUT)util/rbtree.o: ../lib/rbtree.c FORCE
+	$(call rule_mkdir)
+	$(call if_changed_dep,cc_o_c)
+
+$(OUTPUT)util/libstring.o: ../lib/string.c FORCE
 	$(call rule_mkdir)
 	$(call if_changed_dep,cc_o_c)
 

tools/perf/util/include/linux/string.h

···
-#include <string.h>
-
-void *memdup(const void *src, size_t len);

tools/perf/util/string.c

···
 	return s;
 }
 
-/**
- * memdup - duplicate region of memory
- * @src: memory region to duplicate
- * @len: memory region length
- */
-void *memdup(const void *src, size_t len)
-{
-	void *p;
-
-	p = malloc(len);
-	if (p)
-		memcpy(p, src, len);
-
-	return p;
-}
-
 char *asprintf_expr_inout_ints(const char *var, bool in, size_t nints, int *ints)
 {
 	/*