fix symlinkat

parallel-orch/trace_v2.py

@@ -10,8 +10,9 @@
 
 # not handled: listxattr, llistxattr, getxattr, pivot_root, mount, umount2
 # setxattr lsetxattr removexattr lremovexattr, fanotify_mark, renameat2, chroot, quotactl
-# handled individually openat, open, chdir, clone, rename
-# TODO: link, symlink, renameat, symlinkat
+# TODO: link, symlink, renameat
+
+# handled individually openat, open, chdir, clone, rename, symlinkat
 r_first_path_set = set(['execve', 'stat', 'lstat', 'access', 'statfs',
                         'readlink', 'execve', 'getxattr', 'lgetxattr'])
 w_first_path_set = set(['mkdir', 'rmdir', 'truncate', 'creat', 'chmod', 'chown',
@@ -105,6 +106,13 @@ def is_ret_err(ret: str):
     ret = ret.strip()
     return ret[0] == '-'
 
+def get_ret_file_path(ret: str):
+    assert not is_ret_err(ret)
+    ret = ret.strip()
+    start = ret.find('<') + 1
+    end = ret.rfind('>')
+    return ret[start:end]
+
 def convert_absolute(cur_dir, path):
     if is_absolute(path):
         return path
@@ -157,11 +165,12 @@ def handle_open_flag(flags):
         return 'w'
 
 def handle_open_common(total_path, flags, ret):
-    if handle_open_flag(flags) == 'r':
-        return RFile(total_path)
     if is_ret_err(ret):
         return RFile(total_path)
-    return WFile(total_path)
+    elif handle_open_flag(flags) == 'r':
+        return [RFile(total_path), RFile(get_ret_file_path(ret))]
+    else:
+        return [WFile(total_path), WFile(get_ret_file_path(ret))]
 
 def parse_openat(args, ret):
     if args.count(',') <= 2:
@@ -183,7 +192,7 @@ def parse_open(pid, args, ret, ctx):
     return handle_open_common(total_path, flags, ret)
 
 def get_path_from_fd_path(args):
-    a0, a1, _ = args.split(sep=',', maxsplit=2)
+    a0, a1, *_ = args.split(sep=',', maxsplit=2)
     a1 = parse_string(a1)
     if len(a1) and a1[0] == '/':
         return a1
@@ -219,7 +228,11 @@ def parse_clone(pid, args, ret, ctx):
     flags = flags[len('flags='):]
     if has_clone_fs(flags):
         ctx.do_clone(pid, child)
-
+
+def parse_symlinkat(pid, args, ret):
+    a0, rest = args.split(sep=',', maxsplit=1)
+    return parse_w_fd_path(rest, ret)
+
 def parse_syscall(pid, syscall, args, ret, ctx):
     if syscall in r_first_path_set:
         return parse_r_first_path(pid, args, ret, ctx)
@@ -237,6 +250,8 @@ def parse_syscall(pid, syscall, args, ret, ctx):
         return parse_w_fd_path(args, ret)
     elif syscall == 'rename':
         return parse_rename(pid, args, ret, ctx)
+    elif syscall == 'symlinkat':
+        return parse_symlinkat(pid, args, ret)
     elif syscall == 'clone':
         return parse_clone(pid, args, ret, ctx)
     elif syscall in ignore_set:
@@ -302,14 +317,17 @@ def parse_and_gather_cmd_rw_sets(trace_object) -> Tuple[set, set]:
     write_set = set()
     for l in trace_object:
         try:
-            record = parse_line(l, ctx)
+            records = parse_line(l, ctx)
         except Exception:
             logging.debug(l)
             raise ValueError("error while parsing trace")
-        if type(record) is RFile and record.fname != '/dev/tty':
-            read_set.add(record.fname)
-        elif type(record) is WFile and record.fname != '/dev/tty':
-            write_set.add(record.fname)
+        if not isinstance(records, list):
+            records = [records]
+        for record in records:
+            if type(record) is RFile and record.fname != '/dev/tty':
+                read_set.add(record.fname)
+            elif type(record) is WFile and record.fname != '/dev/tty':
+                write_set.add(record.fname)
     return read_set, write_set
 
 def main(fname):