tools/nolibc/string: Implement `strdup()` and `strndup()`

These functions are currently only available on architectures that have
my_syscall6() macro implemented. Since these functions use malloc(),
malloc() uses mmap(), mmap() depends on my_syscall6() macro.

On architectures that don't support my_syscall6(), these function will
always return NULL with errno set to ENOSYS.

Acked-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Ammar Faizi <ammarfaizi2@gnuweeb.org>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>

diff --git a/tools/include/nolibc/string.h b/tools/include/nolibc/string.h
index f43d52a44d0983441b36e17210c821aa6fa25318..bef35bee9c44c4710b3c1cbbcdd3da929b31ec8e 100644 (file)
--- a/tools/include/nolibc/string.h
+++ b/tools/include/nolibc/string.h
@@ -9,6 +9,8 @@
 
 #include "std.h"
 
+static void *malloc(size_t len);
+
 /*
  * As much as possible, please keep functions alphabetically sorted.
  */
@@ -156,6 +158,36 @@ size_t strnlen(const char *str, size_t maxlen)
        return len;
 }
 
+static __attribute__((unused))
+char *strdup(const char *str)
+{
+       size_t len;
+       char *ret;
+
+       len = strlen(str);
+       ret = malloc(len + 1);
+       if (__builtin_expect(ret != NULL, 1))
+               memcpy(ret, str, len + 1);
+
+       return ret;
+}
+
+static __attribute__((unused))
+char *strndup(const char *str, size_t maxlen)
+{
+       size_t len;
+       char *ret;
+
+       len = strnlen(str, maxlen);
+       ret = malloc(len + 1);
+       if (__builtin_expect(ret != NULL, 1)) {
+               memcpy(ret, str, len);
+               ret[len] = '\0';
+       }
+
+       return ret;
+}
+
 static __attribute__((unused))
 size_t strlcat(char *dst, const char *src, size_t size)
 {