correct error size calculation for arrays

Author: varun-r-mallya

pythonbpf/debuginfo/debug_info_generator.py

@@ -81,6 +81,20 @@ def create_array_type(self, base_type: Any, count: int) -> Any:
             },
         )
 
+    def create_array_type_vmlinux(self, type_info: Any, count: int) -> Any:
+        """Create an array type of the given base type with specified count"""
+        base_type, type_sizing = type_info
+        subrange = self.module.add_debug_info("DISubrange", {"count": count})
+        return self.module.add_debug_info(
+            "DICompositeType",
+            {
+                "tag": dc.DW_TAG_array_type,
+                "baseType": base_type,
+                "size": type_sizing,
+                "elements": [subrange],
+            },
+        )
+
     @staticmethod
     def _compute_array_size(base_type: Any, count: int) -> int:
         # Extract size from base_type if possible
@@ -101,7 +115,9 @@ def create_struct_member(self, name: str, base_type: Any, offset: int) -> Any:
             },
         )
 
-    def create_struct_member_vmlinux(self, name: str, base_type_with_size: Any, offset: int) -> Any:
+    def create_struct_member_vmlinux(
+        self, name: str, base_type_with_size: Any, offset: int
+    ) -> Any:
         """Create a struct member with the given name, type, and offset"""
         base_type, type_size = base_type_with_size
         return self.module.add_debug_info(

pythonbpf/vmlinux_parser/ir_gen/debug_info_gen.py

@@ -2,12 +2,15 @@
 from ..dependency_node import DependencyNode
 import ctypes
 import logging
-from typing import List, Any, Tuple, Optional
+from typing import List, Any, Tuple
 
 logger = logging.getLogger(__name__)
 
+
 def debug_info_generation(
-        struct: DependencyNode, llvm_module, generated_debug_info: List[Tuple[DependencyNode, Any]]
+    struct: DependencyNode,
+    llvm_module,
+    generated_debug_info: List[Tuple[DependencyNode, Any]],
 ) -> Any:
     """
     Generate DWARF debug information for a struct defined in a DependencyNode.
@@ -54,11 +57,11 @@ def debug_info_generation(
 
 
 def _get_field_debug_type(
-        field_name: str,
-        field,
-        generator: DebugInfoGenerator,
-        parent_struct: DependencyNode,
-        generated_debug_info: List[Tuple[DependencyNode, Any]]
+    field_name: str,
+    field,
+    generator: DebugInfoGenerator,
+    parent_struct: DependencyNode,
+    generated_debug_info: List[Tuple[DependencyNode, Any]],
 ) -> tuple[Any, int]:
     """
     Determine the appropriate debug type for a field based on its Python/ctypes type.
@@ -77,8 +80,12 @@ def _get_field_debug_type(
     if field.ctype_complex_type is not None:
         if issubclass(field.ctype_complex_type, ctypes.Array):
             # Handle array types
-            element_type, base_type_size = _get_basic_debug_type(field.containing_type, generator)
-            return generator.create_array_type(element_type, field.type_size), field.type_size * base_type_size
+            element_type, base_type_size = _get_basic_debug_type(
+                field.containing_type, generator
+            )
+            return generator.create_array_type_vmlinux(
+                (element_type, base_type_size * field.type_size), field.type_size
+            ), field.type_size * base_type_size
         elif issubclass(field.ctype_complex_type, ctypes._Pointer):
             # Handle pointer types
             pointee_type, _ = _get_basic_debug_type(field.containing_type, generator)
@@ -136,7 +143,9 @@ def _get_basic_debug_type(ctype, generator: DebugInfoGenerator) -> Any:
     elif ctype == ctypes.c_longlong or ctype == ctypes.c_int64:
         return generator.get_basic_type("long long", 64, dc.DW_ATE_signed), 64
     elif ctype == ctypes.c_ulonglong or ctype == ctypes.c_uint64:
-        return generator.get_basic_type("unsigned long long", 64, dc.DW_ATE_unsigned), 64
+        return generator.get_basic_type(
+            "unsigned long long", 64, dc.DW_ATE_unsigned
+        ), 64
     elif ctype == ctypes.c_float:
         return generator.get_basic_type("float", 32, dc.DW_ATE_float), 32
     elif ctype == ctypes.c_double:
@@ -147,9 +156,7 @@ def _get_basic_debug_type(ctype, generator: DebugInfoGenerator) -> Any:
         char_type = generator.get_basic_type("char", 8, dc.DW_ATE_signed_char), 8
         return generator.create_pointer_type(char_type)
     elif ctype == ctypes.c_void_p:
-        void_type = generator.module.add_debug_info(
-            "DIBasicType", {"name": "void"}
-        )
+        void_type = generator.module.add_debug_info("DIBasicType", {"name": "void"})
         return generator.create_pointer_type(void_type), 64
     else:
         return generator.get_uint64_type(), 64

tests/passing_tests/vmlinux/xdp_pass.py

@@ -1,22 +1,20 @@
-from pythonbpf import bpf, map, section, bpfglobal, compile_to_ir, compile
-from pythonbpf.maps import HashMap
-from pythonbpf.helper import XDP_PASS
+from pythonbpf import bpf, section, bpfglobal, compile_to_ir, compile
 from vmlinux import TASK_COMM_LEN  # noqa: F401
-from vmlinux import struct_xdp_md
 from vmlinux import struct_trace_event_raw_sys_enter  # noqa: F401
 from ctypes import c_int64
 
+
 # Instructions to how to run this program
 # 1. Install PythonBPF: pip install pythonbpf
 # 2. Run the program: python examples/xdp_pass.py
 # 3. Run the program with sudo: sudo tools/check.sh run examples/xdp_pass.o
 # 4. Attach object file to any network device with something like ./check.sh xdp examples/xdp_pass.o tailscale0
 # 5. send traffic through the device and observe effects
-
 @bpf
-@section("xdp")
-def hello_world(ctx: struct_xdp_md) -> c_int64:
-    return XDP_PASS
+@section("tracepoint/syscalls/sys_enter_execve")
+def hello_world(ctx: struct_trace_event_raw_sys_enter) -> c_int64:
+    print("Hello, World!")
+    return c_int64(0)
 
 
 @bpf