diff --git a/lisa/_kmod.py b/lisa/_kmod.py
index 07cf89e1138ba0d2dfce7950e1d43bd457ca87fe..7e625e863173d6576d1730184cd24ca7d1852cbf 100644
--- a/lisa/_kmod.py
+++ b/lisa/_kmod.py
@@ -985,7 +985,7 @@ class _KernelBuildEnv(Loggable, SerializeViaConstructor):
 
 
     @classmethod
-    def _prepare_tree(cls, path, cc, abi, build_conf, apply_overlays):
+    def _prepare_tree(cls, path, cc, abi, build_conf, apply_overlays, fixup_atomic_headers=False):
         logger = cls.get_logger()
         path = Path(path)
 
@@ -1025,24 +1025,37 @@ class _KernelBuildEnv(Loggable, SerializeViaConstructor):
         bind_paths = {path: path}
 
         def fixup_kernel_build_env():
-            # TODO: re-assess
-
-            # The headers in /sys/kheaders.tar.xz generated by
-            # CONFIG_IKHEADERS=y are broken since kernel/gen_kheaders.sh strip
-            # some comments from the file. KBuild then proceeds on checking the
-            # checksum and the check fails. This used to be a simple warning,
-            # but has now been turned into an error in recent kernels.
-            # We remove the SHA1 from the file so that the check is skipped.
-            with contextlib.suppress(FileNotFoundError):
-                for _path in (path / 'include' / 'linux' / 'atomic').iterdir():
-                    content = _path.read_bytes()
-                    lines = [line for line in content.split(b'\n') if line]
-                    if lines and lines[-1].lstrip().startswith(b'//'):
-                        # Remove the last line, containing the sha1
-                        content = b'\n'.join(lines[:-1]) + b'\n'
-                        sha1 = hashlib.sha1(content).hexdigest()
-                        content += b'// ' + sha1.encode('ascii') + b'\n'
-                        _path.write_bytes(content)
+
+            if fixup_atomic_headers:
+                # TODO: re-assess
+
+                # The headers in /sys/kheaders.tar.xz generated by
+                # CONFIG_IKHEADERS=y are broken since kernel/gen_kheaders.sh strip
+                # some comments from the file. KBuild then proceeds on checking the
+                # checksum and the check fails. This used to be a simple warning,
+                # but has now been turned into an error in recent kernels.
+                # We remove the SHA1 from the file so that the check is skipped.
+                with contextlib.suppress(FileNotFoundError):
+                    def join(lines):
+                        return b'\n'.join(lines) + b'\n'
+
+                    for _path in (path / 'include' / 'linux' / 'atomic').iterdir():
+                        content = _path.read_bytes()
+                        lines = content.split(b'\n')
+                        i, last_line = [(i, line) for (i, line) in enumerate(lines) if line][-1]
+
+                        if lines and last_line.lstrip().startswith(b'//'):
+                            # Remove the last line, containing the sha1
+                            without_sha1 = copy.copy(lines)
+                            del without_sha1[i]
+                            without_sha1 = join(without_sha1)
+                            sha1 = hashlib.sha1(without_sha1).hexdigest()
+
+                            # Update the sha1
+                            updated = copy.copy(lines)
+                            updated[i] = b'// ' + sha1.encode('ascii')
+                            updated = join(updated)
+                            _path.write_bytes(updated)
 
 
         if build_conf['build-env'] == 'alpine':
@@ -1415,7 +1428,7 @@ class _KernelBuildEnv(Loggable, SerializeViaConstructor):
                     raise ValueError(f'Building from /lib/modules/.../build/ is only supported for local targets')
 
         @contextlib.contextmanager
-        def _from_target_sources(configs, pull):
+        def _from_target_sources(configs, pull, **kwargs):
             """
             Overlay some content taken from the target on the user tree, such
             as /proc/config.gz
@@ -1442,6 +1455,7 @@ class _KernelBuildEnv(Loggable, SerializeViaConstructor):
                         cache=cache,
                         tree_path=tree_path,
                         build_conf=build_conf,
+                        **kwargs,
                     ) as tree:
                         yield tree._to_spec()
 
@@ -1461,6 +1475,7 @@ class _KernelBuildEnv(Loggable, SerializeViaConstructor):
             return _from_target_sources(
                 configs=['CONFIG_IKHEADERS', 'CONFIG_IKCONFIG_PROC'],
                 pull=pull,
+                fixup_atomic_headers=True,
             )
 
         def from_proc_config():
diff --git a/lisa/datautils.py b/lisa/datautils.py
index 6c95b2c9debbd736b51dafd7c3103d72578388d1..800cad94410cc23c99f3b92ef1dde661f44219c5 100644
--- a/lisa/datautils.py
+++ b/lisa/datautils.py
@@ -321,8 +321,8 @@ def df_squash(df, start, end, column='delta'):
     # If s1 is in the interval, we just need to cap its len to
     # s1 - e1.index
 
-    prev_df = df[:start]
-    middle_df = df[start:end]
+    prev_df = df.loc[:start]
+    middle_df = df.loc[start:end]
 
     # Tweak the closest previous event to include it in the slice
     if not prev_df.empty and start not in middle_df.index:
@@ -1851,7 +1851,7 @@ def series_convert(series, dtype, nullable=None):
 
         pipelines.append(
             # Otherwise fallback to calling the type directly
-            lambda series: series.apply(convert, convert_dtype=False)
+            lambda series: series.astype(object).apply(convert)
         )
 
     # Then try with a nullable type.
@@ -1939,20 +1939,19 @@ def series_convert(series, dtype, nullable=None):
         # unusable
         if (
             series.dtype.name == 'object' and
-            series.apply(isinstance, args=(bytes,), convert_dtype=False).any()
+            series.astype(object).apply(isinstance, args=(bytes,)).any()
         ):
             string_basic = None
             # Handle mixed dtypes
-            str_basic = lambda x : x.apply(
+            str_basic = lambda x : x.astype(object).apply(
                 lambda x: x.decode('ascii') if isinstance(x, bytes) else str(x),
-                convert_dtype=False
             )
         else:
             string_basic = basic
             str_basic = make_convert(str)
 
         # Faster than Series.str.decode()
-        basic_decode = lambda x : x.apply(bytes.decode, args=('ascii',), convert_dtype=False)
+        basic_decode = lambda x : x.astype(object).apply(bytes.decode, args=('ascii',))
 
         # Significantly faster than Series.str.decode()
         def fast_decode(x):