93 Commits

Author SHA1 Message Date
3f66c4f53f Initial plan 2025-11-22 07:59:21 +00:00
081ee5cb4c move requests.py to passing tests 2025-11-22 13:19:55 +05:30
a91c3158ad sort fields in debug info by offset order 2025-11-22 12:35:47 +05:30
2b3635fe20 format chore 2025-11-22 01:48:44 +05:30
6f25c554a9 fix CO-RE read for cast structs 2025-11-22 01:47:25 +05:30
84507b8b98 add btf probe read kernel helper 2025-11-22 00:57:12 +05:30
a42a75179d format chore 2025-11-22 00:37:39 +05:30
377fa4041d add regular struct field access handling in vmlinux_registry.py 2025-11-22 00:36:59 +05:30
99321c7669 add a failing C test 2025-11-21 23:01:08 +05:30
11850d16d3 field check in allocation pass 2025-11-21 21:47:58 +05:30
9ee821c7f6 make pointer allocation feasible but subverting LLC 2025-11-21 21:47:55 +05:30
25394059a6 allow casting 2025-11-21 21:47:10 +05:30
fde8eab775 allow allocation pass on vmlinux cast 2025-11-21 21:47:07 +05:30
42b8865a56 Merge branch 'master' into request-struct 2025-11-21 02:10:52 +05:30
144d9b0ab4 change c-file test structure 2025-11-20 17:24:02 +05:30
902a52a07d remove debug print statements 2025-11-20 14:39:13 +05:30
306570953b format chore 2025-11-20 14:18:45 +05:30
740eed45e1 add placeholder debug info to shut llvmlite up about NoneType 2025-11-20 14:17:57 +05:30
c8801f4c3e nonetype not parsed 2025-11-19 23:35:10 +05:30
e5b3b001ce Minor fix for PTR_TO_MAP_VALUE_OR_NULL target 2025-11-19 04:29:35 +05:30
19b42b9a19 Allocate hashmap lookup return vars based on the value type of said hashmap 2025-11-19 04:09:51 +05:30
9f5ec62383 Add get_uint8_type to DebugInfoGenerator 2025-11-19 03:24:40 +05:30
7af54df7c0 Add passing test hash_map_struct.py for using structs as hashmap key/val types 2025-11-19 00:17:01 +05:30
573bbb350e Allow structs to be key/val type for hashmaps 2025-11-19 00:08:15 +05:30
64679f8072 Add skeleton _get_key_val_dbg_type in maps_debug_info.py 2025-11-18 05:00:00 +05:30
5667facf23 Pass down structs_sym_tab to maps_debug_info, allow vmlinux enums to be used in an indexed format for map declaration 2025-11-18 04:34:51 +05:30
4f8af16a17 Pass structs_sym_tab to maps_proc 2025-11-18 04:34:42 +05:30
b84884162d Merge pull request #69 from pythonbpf/symex
Add support for userspace+kernelspace stack trace example using blazesym
2025-11-17 01:47:35 +05:30
e9bb90cb70 Add docstring for bpf_get_stack_emitter 2025-11-17 01:46:57 +05:30
49740598ea format chore 2025-11-13 09:31:10 +05:30
73bbf00e7c add tests 2025-11-13 09:29:53 +05:30
9d76502d5a Fix get_flags_val usage 2025-11-13 02:24:35 +05:30
a10da4a277 Implement bpf_get_stack handler 2025-11-13 00:59:50 +05:30
29e90601b7 Init bpf_get_stack emitter 2025-11-13 00:51:48 +05:30
56df05a93c Janitorial formatting 2025-11-12 14:38:35 +05:30
a55efc6469 Implement output helper for RingBuf maps, add a match-case based dispatch for output helper handlers for multiple map types 2025-11-12 14:06:09 +05:30
64cd2d2fc2 Set minimum supported Python version to 3.10 2025-11-12 14:06:00 +05:30
cbddc0aa96 Introduce MapSymbol to propagate map type info in map_sym_tab 2025-11-12 13:16:23 +05:30
209df33c8f Add RingBuf submit and reserve helpers 2025-11-12 03:53:16 +05:30
7a56e5d0cd Initialize required helpers for ringbuffer 2025-11-12 01:59:07 +05:30
1d7a436c9f Add linting function for RingBuf.discard 2025-11-12 01:30:15 +05:30
5eaeb3e921 Add max_entries constraints for RingBuffer 2025-11-12 01:27:41 +05:30
cd52d0d91b Rename RingBuf map to RingBuffer 2025-11-12 01:07:12 +05:30
df981be095 Janitorial format 2025-11-11 21:08:06 +05:30
316c21c428 Fix char_array to pointer/int detection fallback in helper_utils 2025-11-11 21:00:42 +05:30
c883d95655 Minor fix - check expr type before sending to char_array handler in printk_formatter 2025-11-11 17:43:20 +05:30
f7dee329cb fix nested pointers issue in array generation and also fix zero length array IR generation 2025-11-10 20:29:28 +05:30
5031f90377 fix stacked vmlinux struct parsing issue 2025-11-10 20:06:04 +05:30
95a624044a fix type error 2025-11-08 20:28:56 +05:30
c5bef26b88 add multi imports to single import line. 2025-11-08 18:08:04 +05:30
5a8b64f1d9 Merge pull request #64 from pythonbpf/all_helpers
Add support for all eBPF helpers
2025-11-07 19:26:55 +05:30
faad3555dc Merge pull request #67 from pythonbpf/32int_support
add i32 support and special support for xdp_md with zext
2025-11-05 19:42:05 +05:30
5ad33b011e move a test to passing 2025-11-05 18:02:28 +05:30
2f4785b796 add int type conversion for all vmlinux struct field int types. 2025-11-05 18:01:41 +05:30
c5fdd3bce2 move some tests to passing 2025-11-05 17:48:26 +05:30
b0d35693b9 format chore 2025-11-05 17:44:45 +05:30
44c6ceda27 fix context debug info repetition circular reference error 2025-11-05 17:44:29 +05:30
2685d0a0ee add i32 support special case and find ctx repetition in multiple functions error. 2025-11-05 17:38:38 +05:30
3489f45b63 Add failing XDP vmlinux tests 2025-11-01 18:57:07 +05:30
204ec26154 add i32 support and make it extensible 2025-11-01 14:44:39 +05:30
a9d82d40d3 Merge pull request #60 from pythonbpf/vmlinux-handler
vmlinux handler with struct support for only int64 and unsigned uint64 type struct fields.
2025-11-01 08:15:14 +05:30
85a62d6cd8 add example and support unsigned i64 2025-11-01 08:13:22 +05:30
c3fc790c71 remove fixed TODOs 2025-11-01 07:05:42 +05:30
22e30f04b4 Merge pull request #66 from pythonbpf/dependabot/github_actions/actions-3249c11fdc
Bump the actions group with 2 updates
2025-10-27 17:21:49 +05:30
620b8cb1e7 Bump the actions group with 2 updates
Bumps the actions group with 2 updates: [actions/upload-artifact](https://github.com/actions/upload-artifact) and [actions/download-artifact](https://github.com/actions/download-artifact).


Updates `actions/upload-artifact` from 4 to 5
- [Release notes](https://github.com/actions/upload-artifact/releases)
- [Commits](https://github.com/actions/upload-artifact/compare/v4...v5)

Updates `actions/download-artifact` from 5 to 6
- [Release notes](https://github.com/actions/download-artifact/releases)
- [Commits](https://github.com/actions/download-artifact/compare/v5...v6)

---
updated-dependencies:
- dependency-name: actions/upload-artifact
  dependency-version: '5'
  dependency-type: direct:production
  update-type: version-update:semver-major
  dependency-group: actions
- dependency-name: actions/download-artifact
  dependency-version: '6'
  dependency-type: direct:production
  update-type: version-update:semver-major
  dependency-group: actions
...

Signed-off-by: dependabot[bot] <support@github.com>
2025-10-27 11:49:59 +00:00
1207fe9f92 Update .gitattributes to include new directories 2025-10-27 03:43:38 +05:30
b138405931 Merge pull request #65 from pythonbpf/varun-r-mallya-patch-1
Mark Jupyter Notebook files as vendored
2025-10-27 03:41:59 +05:30
262f00f635 Mark Jupyter Notebook files as vendored 2025-10-27 03:41:15 +05:30
07580dabf2 revert struct reference pointer sizes to i8 to ensure that compiler does not optimize 2025-10-27 03:29:15 +05:30
ac74b03b14 Add TODO to specify flags and DISubprogram. 2025-10-27 03:01:56 +05:30
3bf85e733e add DI subprogram to make CO-RE work fully. 2025-10-27 03:00:13 +05:30
73f7c80eca add scope field separately to subroutine type remove circular dependency 2025-10-27 02:48:06 +05:30
238697469a create debug info to subroutine type 2025-10-27 02:19:08 +05:30
8bd210cede add debug info storage on assignment_info.py dataclass 2025-10-26 15:46:42 +05:30
7bf6f9c48c add function_debug_info.py and format 2025-10-26 15:12:36 +05:30
a1fe2ed4bc change to 64 bit pointers. May be an issue. revert this commit if issues arise 2025-10-26 15:00:53 +05:30
93285dbdd8 geenrate gep IR 2025-10-26 02:12:33 +05:30
1ea44dd8e1 Use pointer arithmetic to resolve vmlinux struct fields 2025-10-25 05:40:45 +05:30
96216d4411 Consistently use Dataclass syntac for AssignmentInfo and related classes 2025-10-25 05:10:47 +05:30
028d9c2c08 generate IR partly 2025-10-25 04:41:13 +05:30
c6b5ecb47e find global variable ir and field data from metadata 2025-10-24 03:34:27 +05:30
30bcfcbbd0 remove compile error on normal c_void_p in arg and separate localsymbol to avoid circular dep 2025-10-24 03:08:39 +05:30
f18a4399ea format chore 2025-10-24 02:40:07 +05:30
4e01df735f complete part of expr passing for attribute of i64 type 2025-10-24 02:38:39 +05:30
64674cf646 add alloc for only i64 2025-10-24 02:06:39 +05:30
36a1a0903e Merge branch 'master' into vmlinux-handler 2025-10-22 12:02:51 +05:30
f2bc7f1434 pass context to memory allocation 2025-10-22 12:01:52 +05:30
b3921c424d parse context from first function argument to local symbol table 2025-10-22 11:40:49 +05:30
adf32560a0 bpf passthrough gen in codegen
Signed-off-by: varun-r-mallya <varunrmallya@gmail.com>
2025-10-22 03:45:54 +05:30
21cea97d78 add return None statements 2025-10-21 07:02:34 +05:30
d8729342dc add bpf_passthrough generation 2025-10-21 07:01:37 +05:30
4179fbfc88 move around examples 2025-10-21 06:03:16 +05:30
ba397036b4 add failing examples to work on 2025-10-21 05:49:44 +05:30
51 changed files with 2252 additions and 121942 deletions

2
.gitattributes vendored
View File

@ -1 +1,3 @@
tests/c-form/vmlinux.h linguist-vendored
examples/ linguist-vendored
BCC-Examples/ linguist-vendored

View File

@ -33,7 +33,7 @@ jobs:
python -m build
- name: Upload distributions
uses: actions/upload-artifact@v4
uses: actions/upload-artifact@v5
with:
name: release-dists
path: dist/
@ -59,7 +59,7 @@ jobs:
steps:
- name: Retrieve release distributions
uses: actions/download-artifact@v5
uses: actions/download-artifact@v6
with:
name: release-dists
path: dist/

View File

@ -68,8 +68,6 @@ def callback(cpu, event):
perf = b["events"].open_perf_buffer(callback, struct_name="data_t")
print("Starting to poll... (Ctrl+C to stop)")
print("Try running: fork() or clone() system calls to trigger events")
try:
while True:
b["events"].poll(1000)

View File

@ -26,7 +26,7 @@ classifiers = [
]
readme = "README.md"
license = {text = "Apache-2.0"}
requires-python = ">=3.8"
requires-python = ">=3.10"
dependencies = [
"llvmlite",

View File

@ -1,28 +1,17 @@
import ast
import logging
import ctypes
from llvmlite import ir
from dataclasses import dataclass
from typing import Any
from .local_symbol import LocalSymbol
from pythonbpf.helper import HelperHandlerRegistry
from pythonbpf.vmlinux_parser.dependency_node import Field
from .expr import VmlinuxHandlerRegistry
from pythonbpf.type_deducer import ctypes_to_ir
from pythonbpf.maps import BPFMapType
logger = logging.getLogger(__name__)
@dataclass
class LocalSymbol:
var: ir.AllocaInstr
ir_type: ir.Type
metadata: Any = None
def __iter__(self):
yield self.var
yield self.ir_type
yield self.metadata
def create_targets_and_rvals(stmt):
"""Create lists of targets and right-hand values from an assignment statement."""
if isinstance(stmt.targets[0], ast.Tuple):
@ -37,7 +26,9 @@ def create_targets_and_rvals(stmt):
return stmt.targets, [stmt.value]
def handle_assign_allocation(builder, stmt, local_sym_tab, structs_sym_tab):
def handle_assign_allocation(
builder, stmt, local_sym_tab, map_sym_tab, structs_sym_tab
):
"""Handle memory allocation for assignment statements."""
logger.info(f"Handling assignment for allocation: {ast.dump(stmt)}")
@ -60,24 +51,16 @@ def handle_assign_allocation(builder, stmt, local_sym_tab, structs_sym_tab):
continue
var_name = target.id
# Skip if already allocated
if var_name in local_sym_tab:
logger.debug(f"Variable {var_name} already allocated, skipping")
continue
# When allocating a variable, check if it's a vmlinux struct type
if isinstance(
stmt.value, ast.Name
) and VmlinuxHandlerRegistry.is_vmlinux_struct(stmt.value.id):
# Handle vmlinux struct allocation
# This requires more implementation
print(stmt.value)
pass
# Determine type and allocate based on rval
if isinstance(rval, ast.Call):
_allocate_for_call(builder, var_name, rval, local_sym_tab, structs_sym_tab)
_allocate_for_call(
builder, var_name, rval, local_sym_tab, map_sym_tab, structs_sym_tab
)
elif isinstance(rval, ast.Constant):
_allocate_for_constant(builder, var_name, rval, local_sym_tab)
elif isinstance(rval, ast.BinOp):
@ -96,14 +79,16 @@ def handle_assign_allocation(builder, stmt, local_sym_tab, structs_sym_tab):
)
def _allocate_for_call(builder, var_name, rval, local_sym_tab, structs_sym_tab):
def _allocate_for_call(
builder, var_name, rval, local_sym_tab, map_sym_tab, structs_sym_tab
):
"""Allocate memory for variable assigned from a call."""
if isinstance(rval.func, ast.Name):
call_type = rval.func.id
# C type constructors
if call_type in ("c_int32", "c_int64", "c_uint32", "c_uint64"):
if call_type in ("c_int32", "c_int64", "c_uint32", "c_uint64", "c_void_p"):
ir_type = ctypes_to_ir(call_type)
var = builder.alloca(ir_type, name=var_name)
var.align = ir_type.width // 8
@ -133,20 +118,91 @@ def _allocate_for_call(builder, var_name, rval, local_sym_tab, structs_sym_tab):
local_sym_tab[var_name] = LocalSymbol(var, struct_info.ir_type, call_type)
logger.info(f"Pre-allocated {var_name} for struct {call_type}")
elif VmlinuxHandlerRegistry.is_vmlinux_struct(call_type):
# When calling struct_name(pointer), we're doing a cast, not construction
# So we allocate as a pointer (i64) not as the actual struct
var = builder.alloca(ir.IntType(64), name=var_name)
var.align = 8
local_sym_tab[var_name] = LocalSymbol(
var, ir.IntType(64), VmlinuxHandlerRegistry.get_struct_type(call_type)
)
logger.info(
f"Pre-allocated {var_name} for vmlinux struct pointer cast to {call_type}"
)
else:
logger.warning(f"Unknown call type for allocation: {call_type}")
elif isinstance(rval.func, ast.Attribute):
# Map method calls - need double allocation for ptr handling
_allocate_for_map_method(builder, var_name, local_sym_tab)
_allocate_for_map_method(
builder, var_name, rval, local_sym_tab, map_sym_tab, structs_sym_tab
)
else:
logger.warning(f"Unsupported call function type for {var_name}")
def _allocate_for_map_method(builder, var_name, local_sym_tab):
def _allocate_for_map_method(
builder, var_name, rval, local_sym_tab, map_sym_tab, structs_sym_tab
):
"""Allocate memory for variable assigned from map method (double alloc)."""
map_name = rval.func.value.id
method_name = rval.func.attr
# NOTE: We will have to special case HashMap.lookup which returns a pointer to value type
# The value type can be a struct as well, so we need to handle that properly
# This special casing is not ideal, as over time other map methods may need similar handling
# But for now, we will just handle lookup specifically
if map_name not in map_sym_tab:
logger.error(f"Map '{map_name}' not found for allocation")
return
if method_name != "lookup":
# Fallback allocation for other map methods
_allocate_for_map_method_fallback(builder, var_name, local_sym_tab)
return
map_params = map_sym_tab[map_name].params
if map_params["type"] != BPFMapType.HASH:
logger.warning(
"Map method lookup used on non-hash map, using fallback allocation"
)
_allocate_for_map_method_fallback(builder, var_name, local_sym_tab)
return
value_type = map_params["value"]
# Determine IR type for value
if isinstance(value_type, str) and value_type in structs_sym_tab:
struct_info = structs_sym_tab[value_type]
value_ir_type = struct_info.ir_type
else:
value_ir_type = ctypes_to_ir(value_type)
if value_ir_type is None:
logger.warning(
f"Could not determine IR type for map value '{value_type}', using fallback allocation"
)
_allocate_for_map_method_fallback(builder, var_name, local_sym_tab)
return
# Main variable (pointer to pointer)
ir_type = ir.PointerType(ir.IntType(64))
var = builder.alloca(ir_type, name=var_name)
local_sym_tab[var_name] = LocalSymbol(var, ir_type)
# Temporary variable for computed values
tmp_ir_type = value_ir_type
var_tmp = builder.alloca(tmp_ir_type, name=f"{var_name}_tmp")
local_sym_tab[f"{var_name}_tmp"] = LocalSymbol(var_tmp, tmp_ir_type)
logger.info(
f"Pre-allocated {var_name} and {var_name}_tmp for map method lookup of type {value_ir_type}"
)
def _allocate_for_map_method_fallback(builder, var_name, local_sym_tab):
"""Fallback allocation for map method variable (i64* and i64**)."""
# Main variable (pointer to pointer)
ir_type = ir.PointerType(ir.IntType(64))
var = builder.alloca(ir_type, name=var_name)
@ -157,7 +213,9 @@ def _allocate_for_map_method(builder, var_name, local_sym_tab):
var_tmp = builder.alloca(tmp_ir_type, name=f"{var_name}_tmp")
local_sym_tab[f"{var_name}_tmp"] = LocalSymbol(var_tmp, tmp_ir_type)
logger.info(f"Pre-allocated {var_name} and {var_name}_tmp for map method")
logger.info(
f"Pre-allocated {var_name} and {var_name}_tmp for map method (fallback)"
)
def _allocate_for_constant(builder, var_name, rval, local_sym_tab):
@ -264,9 +322,87 @@ def _allocate_for_attribute(builder, var_name, rval, local_sym_tab, structs_sym_
logger.error(f"Struct variable '{struct_var}' not found")
return
struct_type = local_sym_tab[struct_var].metadata
struct_type: type = local_sym_tab[struct_var].metadata
if not struct_type or struct_type not in structs_sym_tab:
logger.error(f"Struct type '{struct_type}' not found")
if VmlinuxHandlerRegistry.is_vmlinux_struct(struct_type.__name__):
# Handle vmlinux struct field access
vmlinux_struct_name = struct_type.__name__
if not VmlinuxHandlerRegistry.has_field(vmlinux_struct_name, field_name):
logger.error(
f"Field '{field_name}' not found in vmlinux struct '{vmlinux_struct_name}'"
)
return
field_type: tuple[ir.GlobalVariable, Field] = (
VmlinuxHandlerRegistry.get_field_type(vmlinux_struct_name, field_name)
)
field_ir, field = field_type
# Determine the actual IR type based on the field's type
actual_ir_type = None
# Check if it's a ctypes primitive
if field.type.__module__ == ctypes.__name__:
try:
field_size_bytes = ctypes.sizeof(field.type)
field_size_bits = field_size_bytes * 8
if field_size_bits in [8, 16, 32, 64]:
# Special case: struct_xdp_md i32 fields should allocate as i64
# because load_ctx_field will zero-extend them to i64
if (
vmlinux_struct_name == "struct_xdp_md"
and field_size_bits == 32
):
actual_ir_type = ir.IntType(64)
logger.info(
f"Allocating {var_name} as i64 for i32 field from struct_xdp_md.{field_name} "
"(will be zero-extended during load)"
)
else:
actual_ir_type = ir.IntType(field_size_bits)
else:
logger.warning(
f"Unusual field size {field_size_bits} bits for {field_name}"
)
actual_ir_type = ir.IntType(64)
except Exception as e:
logger.warning(
f"Could not determine size for ctypes field {field_name}: {e}"
)
actual_ir_type = ir.IntType(64)
# Check if it's a nested vmlinux struct or complex type
elif field.type.__module__ == "vmlinux":
# For pointers to structs, use pointer type (64-bit)
if field.ctype_complex_type is not None and issubclass(
field.ctype_complex_type, ctypes._Pointer
):
actual_ir_type = ir.IntType(64) # Pointer is always 64-bit
# For embedded structs, this is more complex - might need different handling
else:
logger.warning(
f"Field {field_name} is a nested vmlinux struct, using i64 for now"
)
actual_ir_type = ir.IntType(64)
else:
logger.warning(
f"Unknown field type module {field.type.__module__} for {field_name}"
)
actual_ir_type = ir.IntType(64)
# Allocate with the actual IR type
var = _allocate_with_type(builder, var_name, actual_ir_type)
local_sym_tab[var_name] = LocalSymbol(
var, actual_ir_type, field
) # <-- Store Field metadata
logger.info(
f"Pre-allocated {var_name} as {actual_ir_type} from vmlinux struct {vmlinux_struct_name}.{field_name}"
)
return
else:
logger.error(f"Struct type '{struct_type}' not found")
return
struct_info = structs_sym_tab[struct_type]

View File

@ -1,8 +1,12 @@
import ast
import logging
from inspect import isclass
from llvmlite import ir
from pythonbpf.expr import eval_expr
from pythonbpf.helper import emit_probe_read_kernel_str_call
from pythonbpf.type_deducer import ctypes_to_ir
from pythonbpf.vmlinux_parser.dependency_node import Field
logger = logging.getLogger(__name__)
@ -146,9 +150,57 @@ def handle_variable_assignment(
return False
val, val_type = val_result
logger.info(f"Evaluated value for {var_name}: {val} of type {val_type}, {var_type}")
logger.info(
f"Evaluated value for {var_name}: {val} of type {val_type}, expected {var_type}"
)
if val_type != var_type:
if isinstance(val_type, ir.IntType) and isinstance(var_type, ir.IntType):
# Handle vmlinux struct pointers - they're represented as Python classes but are i64 pointers
if isclass(val_type) and (val_type.__module__ == "vmlinux"):
logger.info("Handling vmlinux struct pointer assignment")
# vmlinux struct pointers: val is a pointer, need to convert to i64
if isinstance(var_type, ir.IntType) and var_type.width == 64:
# Convert pointer to i64 using ptrtoint
if isinstance(val.type, ir.PointerType):
val = builder.ptrtoint(val, ir.IntType(64))
logger.info(
"Converted vmlinux struct pointer to i64 using ptrtoint"
)
builder.store(val, var_ptr)
logger.info(f"Assigned vmlinux struct pointer to {var_name} (i64)")
return True
else:
logger.error(
f"Type mismatch: vmlinux struct pointer requires i64, got {var_type}"
)
return False
if isinstance(val_type, Field):
logger.info("Handling assignment to struct field")
# Special handling for struct_xdp_md i32 fields that are zero-extended to i64
# The load_ctx_field already extended them, so val is i64 but val_type.type shows c_uint
if (
hasattr(val_type, "type")
and val_type.type.__name__ == "c_uint"
and isinstance(var_type, ir.IntType)
and var_type.width == 64
):
# This is the struct_xdp_md case - value is already i64
builder.store(val, var_ptr)
logger.info(
f"Assigned zero-extended struct_xdp_md i32 field to {var_name} (i64)"
)
return True
# TODO: handling only ctype struct fields for now. Handle other stuff too later.
elif var_type == ctypes_to_ir(val_type.type.__name__):
builder.store(val, var_ptr)
logger.info(f"Assigned ctype struct field to {var_name}")
return True
else:
logger.error(
f"Failed to assign ctype struct field to {var_name}: {val_type} != {var_type}"
)
return False
elif isinstance(val_type, ir.IntType) and isinstance(var_type, ir.IntType):
# Allow implicit int widening
if val_type.width < var_type.width:
val = builder.sext(val, var_type)

View File

@ -37,6 +37,24 @@ def finalize_module(original_str):
return re.sub(pattern, replacement, original_str)
def bpf_passthrough_gen(module):
i32_ty = ir.IntType(32)
ptr_ty = ir.PointerType(ir.IntType(8))
fnty = ir.FunctionType(ptr_ty, [i32_ty, ptr_ty])
# Declare the intrinsic
passthrough = ir.Function(module, fnty, "llvm.bpf.passthrough.p0.p0")
# Set function attributes
# TODO: the ones commented are supposed to be there but cannot be added due to llvmlite limitations at the moment
# passthrough.attributes.add("nofree")
# passthrough.attributes.add("nosync")
passthrough.attributes.add("nounwind")
# passthrough.attributes.add("memory(none)")
return passthrough
def find_bpf_chunks(tree):
"""Find all functions decorated with @bpf in the AST."""
bpf_functions = []
@ -57,6 +75,8 @@ def processor(source_code, filename, module):
for func_node in bpf_chunks:
logger.info(f"Found BPF function/struct: {func_node.name}")
bpf_passthrough_gen(module)
vmlinux_symtab = vmlinux_proc(tree, module)
if vmlinux_symtab:
handler = VmlinuxHandler.initialize(vmlinux_symtab)
@ -66,7 +86,7 @@ def processor(source_code, filename, module):
license_processing(tree, module)
globals_processing(tree, module)
structs_sym_tab = structs_proc(tree, module, bpf_chunks)
map_sym_tab = maps_proc(tree, module, bpf_chunks)
map_sym_tab = maps_proc(tree, module, bpf_chunks, structs_sym_tab)
func_proc(tree, module, bpf_chunks, map_sym_tab, structs_sym_tab)
globals_list_creation(tree, module)
@ -137,7 +157,7 @@ def compile_to_ir(filename: str, output: str, loglevel=logging.INFO):
module.add_named_metadata("llvm.ident", [f"PythonBPF {VERSION}"])
module_string = finalize_module(str(module))
module_string: str = finalize_module(str(module))
logger.info(f"IR written to {output}")
with open(output, "w") as f:
@ -198,13 +218,11 @@ def compile(loglevel=logging.WARNING) -> bool:
def BPF(loglevel=logging.WARNING) -> BpfObject:
caller_frame = inspect.stack()[1]
src = inspect.getsource(caller_frame.frame)
with tempfile.NamedTemporaryFile(
mode="w+", delete=True, suffix=".py"
) as f, tempfile.NamedTemporaryFile(
mode="w+", delete=True, suffix=".ll"
) as inter, tempfile.NamedTemporaryFile(
mode="w+", delete=False, suffix=".o"
) as obj_file:
with (
tempfile.NamedTemporaryFile(mode="w+", delete=True, suffix=".py") as f,
tempfile.NamedTemporaryFile(mode="w+", delete=True, suffix=".ll") as inter,
tempfile.NamedTemporaryFile(mode="w+", delete=False, suffix=".o") as obj_file,
):
f.write(src)
f.flush()
source = f.name

View File

@ -49,6 +49,10 @@ class DebugInfoGenerator:
)
return self._type_cache[key]
def get_uint8_type(self) -> Any:
"""Get debug info for signed 8-bit integer"""
return self.get_basic_type("char", 8, dc.DW_ATE_unsigned)
def get_int32_type(self) -> Any:
"""Get debug info for signed 32-bit integer"""
return self.get_basic_type("int", 32, dc.DW_ATE_signed)
@ -184,3 +188,83 @@ class DebugInfoGenerator:
"DIGlobalVariableExpression",
{"var": global_var, "expr": self.module.add_debug_info("DIExpression", {})},
)
def get_int64_type(self):
return self.get_basic_type("long", 64, dc.DW_ATE_signed)
def create_subroutine_type(self, return_type, param_types):
"""
Create a DISubroutineType given return type and list of parameter types.
Equivalent to: !DISubroutineType(types: !{ret, args...})
"""
type_array = [return_type]
if isinstance(param_types, (list, tuple)):
type_array.extend(param_types)
else:
type_array.append(param_types)
return self.module.add_debug_info("DISubroutineType", {"types": type_array})
def create_local_variable_debug_info(
self, name: str, arg: int, var_type: Any
) -> Any:
"""
Create debug info for a local variable (DILocalVariable) without scope.
Example:
!DILocalVariable(name: "ctx", arg: 1, file: !3, line: 20, type: !7)
"""
return self.module.add_debug_info(
"DILocalVariable",
{
"name": name,
"arg": arg,
"file": self.module._file_metadata,
"type": var_type,
},
)
def add_scope_to_local_variable(self, local_variable_debug_info, scope_value):
"""
Add scope information to an existing local variable debug info object.
"""
# TODO: this is a workaround a flaw in the debug info generation. Fix this if possible in the future.
# We should not be touching llvmlite's internals like this.
if hasattr(local_variable_debug_info, "operands"):
# LLVM metadata operands is a tuple, so we need to rebuild it
existing_operands = local_variable_debug_info.operands
# Convert tuple to list, add scope, convert back to tuple
operands_list = list(existing_operands)
operands_list.append(("scope", scope_value))
# Reassign the new tuple
local_variable_debug_info.operands = tuple(operands_list)
def create_subprogram(
self, name: str, subroutine_type: Any, retained_nodes: List[Any]
) -> Any:
"""
Create a DISubprogram for a function.
Args:
name: Function name
subroutine_type: DISubroutineType for the function signature
retained_nodes: List of DILocalVariable nodes for function parameters/variables
Returns:
DISubprogram metadata
"""
return self.module.add_debug_info(
"DISubprogram",
{
"name": name,
"scope": self.module._file_metadata,
"file": self.module._file_metadata,
"type": subroutine_type,
# TODO: the following flags do not exist at the moment in our dwarf constants file. We need to add them.
# "flags": dc.DW_FLAG_Prototyped | dc.DW_FLAG_AllCallsDescribed,
# "spFlags": dc.DW_SPFLAG_Definition | dc.DW_SPFLAG_Optimized,
"unit": self.module._debug_compile_unit,
"retainedNodes": retained_nodes,
},
is_distinct=True,
)

View File

@ -13,6 +13,7 @@ from .type_normalization import (
deref_to_depth,
)
from .vmlinux_registry import VmlinuxHandlerRegistry
from ..vmlinux_parser.dependency_node import Field
logger: Logger = logging.getLogger(__name__)
@ -72,20 +73,36 @@ def _handle_attribute_expr(
if var_name in local_sym_tab:
var_ptr, var_type, var_metadata = local_sym_tab[var_name]
logger.info(f"Loading attribute {attr_name} from variable {var_name}")
logger.info(f"Variable type: {var_type}, Variable ptr: {var_ptr}")
metadata = structs_sym_tab[var_metadata]
if attr_name in metadata.fields:
logger.info(
f"Variable type: {var_type}, Variable ptr: {var_ptr}, Variable Metadata: {var_metadata}"
)
if (
hasattr(var_metadata, "__module__")
and var_metadata.__module__ == "vmlinux"
):
# Try vmlinux handler when var_metadata is not a string, but has a module attribute.
# This has been done to keep everything separate in vmlinux struct handling.
vmlinux_result = VmlinuxHandlerRegistry.handle_attribute(
expr, local_sym_tab, None, builder
)
if vmlinux_result is not None:
return vmlinux_result
else:
raise RuntimeError("Vmlinux struct did not process successfully")
elif isinstance(var_metadata, Field):
logger.error(
f"Cannot access field '{attr_name}' on already-loaded field value '{var_name}'"
)
return None
# Regular user-defined struct
metadata = structs_sym_tab.get(var_metadata)
if metadata and attr_name in metadata.fields:
gep = metadata.gep(builder, var_ptr, attr_name)
val = builder.load(gep)
field_type = metadata.field_type(attr_name)
return val, field_type
# Try vmlinux handler as fallback
vmlinux_result = VmlinuxHandlerRegistry.handle_attribute(
expr, local_sym_tab, None, builder
)
if vmlinux_result is not None:
return vmlinux_result
return None
@ -271,16 +288,45 @@ def _handle_ctypes_call(
call_type = expr.func.id
expected_type = ctypes_to_ir(call_type)
if val[1] != expected_type:
# Extract the actual IR value and type
# val could be (value, ir_type) or (value, Field)
value, val_type = val
# If val_type is a Field object (from vmlinux struct), get the actual IR type of the value
if isinstance(val_type, Field):
# The value is already the correct IR value (potentially zero-extended)
# Get the IR type from the value itself
actual_ir_type = value.type
logger.info(
f"Converting vmlinux field {val_type.name} (IR type: {actual_ir_type}) to {call_type}"
)
else:
actual_ir_type = val_type
if actual_ir_type != expected_type:
# NOTE: We are only considering casting to and from int types for now
if isinstance(val[1], ir.IntType) and isinstance(expected_type, ir.IntType):
if val[1].width < expected_type.width:
val = (builder.sext(val[0], expected_type), expected_type)
if isinstance(actual_ir_type, ir.IntType) and isinstance(
expected_type, ir.IntType
):
if actual_ir_type.width < expected_type.width:
value = builder.sext(value, expected_type)
logger.info(
f"Sign-extended from i{actual_ir_type.width} to i{expected_type.width}"
)
elif actual_ir_type.width > expected_type.width:
value = builder.trunc(value, expected_type)
logger.info(
f"Truncated from i{actual_ir_type.width} to i{expected_type.width}"
)
else:
val = (builder.trunc(val[0], expected_type), expected_type)
# Same width, just use as-is (e.g., both i64)
pass
else:
raise ValueError(f"Type mismatch: expected {expected_type}, got {val[1]}")
return val
raise ValueError(
f"Type mismatch: expected {expected_type}, got {actual_ir_type} (original type: {val_type})"
)
return value, expected_type
def _handle_compare(
@ -487,6 +533,66 @@ def _handle_boolean_op(
return None
# ============================================================================
# VMLinux casting
# ============================================================================
def _handle_vmlinux_cast(
func,
module,
builder,
expr,
local_sym_tab,
map_sym_tab,
structs_sym_tab=None,
):
# handle expressions such as struct_request(ctx.di) where struct_request is a vmlinux
# struct and ctx.di is a pointer to a struct but is actually represented as a c_uint64
# which needs to be cast to a pointer. This is also a field of another vmlinux struct
"""Handle vmlinux struct cast expressions like struct_request(ctx.di)."""
if len(expr.args) != 1:
logger.info("vmlinux struct cast takes exactly one argument")
return None
# Get the struct name
struct_name = expr.func.id
# Evaluate the argument (e.g., ctx.di which is a c_uint64)
arg_result = eval_expr(
func,
module,
builder,
expr.args[0],
local_sym_tab,
map_sym_tab,
structs_sym_tab,
)
if arg_result is None:
logger.info("Failed to evaluate argument to vmlinux struct cast")
return None
arg_val, arg_type = arg_result
# Get the vmlinux struct type
vmlinux_struct_type = VmlinuxHandlerRegistry.get_struct_type(struct_name)
if vmlinux_struct_type is None:
logger.error(f"Failed to get vmlinux struct type for {struct_name}")
return None
# Cast the integer/value to a pointer to the struct
# If arg_val is an integer type, we need to inttoptr it
ptr_type = ir.PointerType()
# TODO: add a integer check here later
if ctypes_to_ir(arg_type.type.__name__):
# Cast integer to pointer
casted_ptr = builder.inttoptr(arg_val, ptr_type)
else:
logger.error(f"Unsupported type for vmlinux cast: {arg_type}")
return None
return casted_ptr, vmlinux_struct_type
# ============================================================================
# Expression Dispatcher
# ============================================================================
@ -507,6 +613,18 @@ def eval_expr(
elif isinstance(expr, ast.Constant):
return _handle_constant_expr(module, builder, expr)
elif isinstance(expr, ast.Call):
if isinstance(expr.func, ast.Name) and VmlinuxHandlerRegistry.is_vmlinux_struct(
expr.func.id
):
return _handle_vmlinux_cast(
func,
module,
builder,
expr,
local_sym_tab,
map_sym_tab,
structs_sym_tab,
)
if isinstance(expr.func, ast.Name) and expr.func.id == "deref":
return _handle_deref_call(expr, local_sym_tab, builder)

View File

@ -1,5 +1,7 @@
import ast
from pythonbpf.vmlinux_parser.vmlinux_exports_handler import VmlinuxHandler
class VmlinuxHandlerRegistry:
"""Registry for vmlinux handler operations"""
@ -7,7 +9,7 @@ class VmlinuxHandlerRegistry:
_handler = None
@classmethod
def set_handler(cls, handler):
def set_handler(cls, handler: VmlinuxHandler):
"""Set the vmlinux handler"""
cls._handler = handler
@ -37,9 +39,37 @@ class VmlinuxHandlerRegistry:
)
return None
@classmethod
def get_struct_debug_info(cls, name):
if cls._handler is None:
return False
return cls._handler.get_struct_debug_info(name)
@classmethod
def is_vmlinux_struct(cls, name):
"""Check if a name refers to a vmlinux struct"""
if cls._handler is None:
return False
return cls._handler.is_vmlinux_struct(name)
@classmethod
def get_struct_type(cls, name):
"""Try to handle a struct name as vmlinux struct"""
if cls._handler is None:
return None
return cls._handler.get_vmlinux_struct_type(name)
@classmethod
def has_field(cls, vmlinux_struct_name, field_name):
"""Check if a vmlinux struct has a specific field"""
if cls._handler is None:
return False
return cls._handler.has_field(vmlinux_struct_name, field_name)
@classmethod
def get_field_type(cls, vmlinux_struct_name, field_name):
"""Get the type of a field in a vmlinux struct"""
if cls._handler is None:
return None
assert isinstance(cls._handler, VmlinuxHandler)
return cls._handler.get_field_type(vmlinux_struct_name, field_name)

View File

@ -0,0 +1,82 @@
import ast
import llvmlite.ir as ir
import logging
from pythonbpf.debuginfo import DebugInfoGenerator
from pythonbpf.expr import VmlinuxHandlerRegistry
import ctypes
logger = logging.getLogger(__name__)
def generate_function_debug_info(
func_node: ast.FunctionDef, module: ir.Module, func: ir.Function
):
generator = DebugInfoGenerator(module)
leading_argument = func_node.args.args[0]
leading_argument_name = leading_argument.arg
annotation = leading_argument.annotation
if func_node.returns is None:
# TODO: should check if this logic is consistent with function return type handling elsewhere
return_type = ctypes.c_int64()
elif hasattr(func_node.returns, "id"):
return_type = func_node.returns.id
if return_type == "c_int32":
return_type = generator.get_int32_type()
elif return_type == "c_int64":
return_type = generator.get_int64_type()
elif return_type == "c_uint32":
return_type = generator.get_uint32_type()
elif return_type == "c_uint64":
return_type = generator.get_uint64_type()
else:
logger.warning(
"Return type should be int32, int64, uint32 or uint64 only. Falling back to int64"
)
return_type = generator.get_int64_type()
else:
return_type = ctypes.c_int64()
# context processing
if annotation is None:
logger.warning("Type of context of function not found.")
return
if hasattr(annotation, "id"):
ctype_name = annotation.id
if ctype_name == "c_void_p":
return
elif ctype_name.startswith("ctypes"):
raise SyntaxError(
"The first argument should always be a pointer to a struct or a void pointer"
)
context_debug_info = VmlinuxHandlerRegistry.get_struct_debug_info(annotation.id)
# Create pointer to context this must be created fresh for each function
# to avoid circular reference issues when the same struct is used in multiple functions
pointer_to_context_debug_info = generator.create_pointer_type(
context_debug_info, 64
)
# Create subroutine type - also fresh for each function
subroutine_type = generator.create_subroutine_type(
return_type, pointer_to_context_debug_info
)
# Create local variable - fresh for each function with unique name
context_local_variable = generator.create_local_variable_debug_info(
leading_argument_name, 1, pointer_to_context_debug_info
)
retained_nodes = [context_local_variable]
logger.info(f"Generating debug info for function {func_node.name}")
# Create subprogram with is_distinct=True to ensure each function gets unique debug info
subprogram_debug_info = generator.create_subprogram(
func_node.name, subroutine_type, retained_nodes
)
generator.add_scope_to_local_variable(
context_local_variable, subprogram_debug_info
)
func.set_metadata("dbg", subprogram_debug_info)
else:
logger.error(f"Invalid annotation type for argument '{leading_argument_name}'")

View File

@ -7,7 +7,12 @@ from pythonbpf.helper import (
reset_scratch_pool,
)
from pythonbpf.type_deducer import ctypes_to_ir
from pythonbpf.expr import eval_expr, handle_expr, convert_to_bool
from pythonbpf.expr import (
eval_expr,
handle_expr,
convert_to_bool,
VmlinuxHandlerRegistry,
)
from pythonbpf.assign_pass import (
handle_variable_assignment,
handle_struct_field_assignment,
@ -16,8 +21,9 @@ from pythonbpf.allocation_pass import (
handle_assign_allocation,
allocate_temp_pool,
create_targets_and_rvals,
LocalSymbol,
)
from .function_debug_info import generate_function_debug_info
from .return_utils import handle_none_return, handle_xdp_return, is_xdp_name
from .function_metadata import get_probe_string, is_global_function, infer_return_type
@ -141,7 +147,9 @@ def allocate_mem(
structs_sym_tab,
)
elif isinstance(stmt, ast.Assign):
handle_assign_allocation(builder, stmt, local_sym_tab, structs_sym_tab)
handle_assign_allocation(
builder, stmt, local_sym_tab, map_sym_tab, structs_sym_tab
)
allocate_temp_pool(builder, max_temps_needed, local_sym_tab)
@ -338,6 +346,28 @@ def process_func_body(
local_sym_tab = {}
# Add the context parameter (first function argument) to the local symbol table
if func_node.args.args and len(func_node.args.args) > 0:
context_arg = func_node.args.args[0]
context_name = context_arg.arg
if hasattr(context_arg, "annotation") and context_arg.annotation:
if isinstance(context_arg.annotation, ast.Name):
context_type_name = context_arg.annotation.id
elif isinstance(context_arg.annotation, ast.Attribute):
context_type_name = context_arg.annotation.attr
else:
raise TypeError(
f"Unsupported annotation type: {ast.dump(context_arg.annotation)}"
)
if VmlinuxHandlerRegistry.is_vmlinux_struct(context_type_name):
resolved_type = VmlinuxHandlerRegistry.get_struct_type(
context_type_name
)
context_type = LocalSymbol(None, None, resolved_type)
local_sym_tab[context_name] = context_type
logger.info(f"Added argument '{context_name}' to local symbol table")
# pre-allocate dynamic variables
local_sym_tab = allocate_mem(
module,
@ -388,7 +418,7 @@ def process_bpf_chunk(func_node, module, return_type, map_sym_tab, structs_sym_t
func.linkage = "dso_local"
func.attributes.add("nounwind")
func.attributes.add("noinline")
func.attributes.add("optnone")
# func.attributes.add("optnone")
if func_node.args.args:
# Only look at the first argument for now
@ -426,7 +456,7 @@ def func_proc(tree, module, chunks, map_sym_tab, structs_sym_tab):
func_type = get_probe_string(func_node)
logger.info(f"Found probe_string of {func_node.name}: {func_type}")
process_bpf_chunk(
func = process_bpf_chunk(
func_node,
module,
ctypes_to_ir(infer_return_type(func_node)),
@ -434,6 +464,9 @@ def func_proc(tree, module, chunks, map_sym_tab, structs_sym_tab):
structs_sym_tab,
)
logger.info(f"Generating Debug Info for Function {func_node.name}")
generate_function_debug_info(func_node, module, func)
# TODO: WIP, for string assignment to fixed-size arrays
def assign_string_to_array(builder, target_array_ptr, source_string_ptr, array_length):

View File

@ -1,6 +1,10 @@
from .helper_registry import HelperHandlerRegistry
from .helper_utils import reset_scratch_pool
from .bpf_helper_handler import handle_helper_call, emit_probe_read_kernel_str_call
from .bpf_helper_handler import (
handle_helper_call,
emit_probe_read_kernel_str_call,
emit_probe_read_kernel_call,
)
from .helpers import (
ktime,
pid,
@ -12,6 +16,7 @@ from .helpers import (
smp_processor_id,
uid,
skb_store_bytes,
get_stack,
XDP_DROP,
XDP_PASS,
)
@ -73,6 +78,7 @@ __all__ = [
"reset_scratch_pool",
"handle_helper_call",
"emit_probe_read_kernel_str_call",
"emit_probe_read_kernel_call",
"ktime",
"pid",
"deref",
@ -83,6 +89,7 @@ __all__ = [
"smp_processor_id",
"uid",
"skb_store_bytes",
"get_stack",
"XDP_DROP",
"XDP_PASS",
]

View File

@ -12,11 +12,10 @@ from .helper_utils import (
get_int_value_from_arg,
)
from .printk_formatter import simple_string_print, handle_fstring_print
from logging import Logger
from pythonbpf.maps import BPFMapType
import logging
logger: Logger = logging.getLogger(__name__)
logger = logging.getLogger(__name__)
class BPFHelperID(Enum):
@ -33,7 +32,13 @@ class BPFHelperID(Enum):
BPF_GET_CURRENT_UID_GID = 15
BPF_GET_CURRENT_COMM = 16
BPF_PERF_EVENT_OUTPUT = 25
BPF_GET_STACK = 67
BPF_PROBE_READ_KERNEL_STR = 115
BPF_PROBE_READ_KERNEL = 113
BPF_RINGBUF_OUTPUT = 130
BPF_RINGBUF_RESERVE = 131
BPF_RINGBUF_SUBMIT = 132
BPF_RINGBUF_DISCARD = 133
@HelperHandlerRegistry.register(
@ -91,9 +96,9 @@ def bpf_map_lookup_elem_emitter(
map_void_ptr = builder.bitcast(map_ptr, ir.PointerType())
# TODO: I have changed the return type to i64*, as we are
# allocating space for that type in allocate_mem. This is
# temporary, and we will honour other widths later. But this
# allows us to have cool binary ops on the returned value.
# allocating space for that type in allocate_mem. This is
# temporary, and we will honour other widths later. But this
# allows us to have cool binary ops on the returned value.
fn_type = ir.FunctionType(
ir.PointerType(ir.IntType(64)), # Return type: void*
[ir.PointerType(), ir.PointerType()], # Args: (void*, void*)
@ -358,11 +363,6 @@ def bpf_get_current_pid_tgid_emitter(
return pid, ir.IntType(64)
@HelperHandlerRegistry.register(
"output",
param_types=[ir.PointerType(ir.IntType(8))],
return_type=ir.IntType(64),
)
def bpf_perf_event_output_handler(
call,
map_ptr,
@ -373,6 +373,10 @@ def bpf_perf_event_output_handler(
struct_sym_tab=None,
map_sym_tab=None,
):
"""
Emit LLVM IR for bpf_perf_event_output helper function call.
"""
if len(call.args) != 1:
raise ValueError(
f"Perf event output expects exactly one argument, got {len(call.args)}"
@ -410,6 +414,98 @@ def bpf_perf_event_output_handler(
return result, None
def bpf_ringbuf_output_emitter(
call,
map_ptr,
module,
builder,
func,
local_sym_tab=None,
struct_sym_tab=None,
map_sym_tab=None,
):
"""
Emit LLVM IR for bpf_ringbuf_output helper function call.
"""
if len(call.args) != 1:
raise ValueError(
f"Ringbuf output expects exactly one argument, got {len(call.args)}"
)
data_arg = call.args[0]
data_ptr, size_val = get_data_ptr_and_size(data_arg, local_sym_tab, struct_sym_tab)
flags_val = ir.Constant(ir.IntType(64), 0)
map_void_ptr = builder.bitcast(map_ptr, ir.PointerType())
data_void_ptr = builder.bitcast(data_ptr, ir.PointerType())
fn_type = ir.FunctionType(
ir.IntType(64),
[
ir.PointerType(),
ir.PointerType(),
ir.IntType(64),
ir.IntType(64),
],
var_arg=False,
)
fn_ptr_type = ir.PointerType(fn_type)
# helper id
fn_addr = ir.Constant(ir.IntType(64), BPFHelperID.BPF_RINGBUF_OUTPUT.value)
fn_ptr = builder.inttoptr(fn_addr, fn_ptr_type)
result = builder.call(
fn_ptr, [map_void_ptr, data_void_ptr, size_val, flags_val], tail=False
)
return result, None
@HelperHandlerRegistry.register(
"output",
param_types=[ir.PointerType(ir.IntType(8))],
return_type=ir.IntType(64),
)
def handle_output_helper(
call,
map_ptr,
module,
builder,
func,
local_sym_tab=None,
struct_sym_tab=None,
map_sym_tab=None,
):
"""
Route output helper to the appropriate emitter based on map type.
"""
match map_sym_tab[map_ptr.name].type:
case BPFMapType.PERF_EVENT_ARRAY:
return bpf_perf_event_output_handler(
call,
map_ptr,
module,
builder,
func,
local_sym_tab,
struct_sym_tab,
map_sym_tab,
)
case BPFMapType.RINGBUF:
return bpf_ringbuf_output_emitter(
call,
map_ptr,
module,
builder,
func,
local_sym_tab,
struct_sym_tab,
map_sym_tab,
)
case _:
logger.error("Unsupported map type for output helper.")
raise NotImplementedError("Output helper for this map type is not implemented.")
def emit_probe_read_kernel_str_call(builder, dst_ptr, dst_size, src_ptr):
"""Emit LLVM IR call to bpf_probe_read_kernel_str"""
@ -479,6 +575,75 @@ def bpf_probe_read_kernel_str_emitter(
return result, ir.IntType(64)
def emit_probe_read_kernel_call(builder, dst_ptr, dst_size, src_ptr):
"""Emit LLVM IR call to bpf_probe_read_kernel"""
fn_type = ir.FunctionType(
ir.IntType(64),
[ir.PointerType(), ir.IntType(32), ir.PointerType()],
var_arg=False,
)
fn_ptr = builder.inttoptr(
ir.Constant(ir.IntType(64), BPFHelperID.BPF_PROBE_READ_KERNEL.value),
ir.PointerType(fn_type),
)
result = builder.call(
fn_ptr,
[
builder.bitcast(dst_ptr, ir.PointerType()),
ir.Constant(ir.IntType(32), dst_size),
builder.bitcast(src_ptr, ir.PointerType()),
],
tail=False,
)
logger.info(f"Emitted bpf_probe_read_kernel (size={dst_size})")
return result
@HelperHandlerRegistry.register(
"probe_read_kernel",
param_types=[
ir.PointerType(ir.IntType(8)),
ir.PointerType(ir.IntType(8)),
],
return_type=ir.IntType(64),
)
def bpf_probe_read_kernel_emitter(
call,
map_ptr,
module,
builder,
func,
local_sym_tab=None,
struct_sym_tab=None,
map_sym_tab=None,
):
"""Emit LLVM IR for bpf_probe_read_kernel helper."""
if len(call.args) != 2:
raise ValueError(
f"probe_read_kernel expects 2 args (dst, src), got {len(call.args)}"
)
# Get destination buffer (char array -> i8*)
dst_ptr, dst_size = get_or_create_ptr_from_arg(
func, module, call.args[0], builder, local_sym_tab, map_sym_tab, struct_sym_tab
)
# Get source pointer (evaluate expression)
src_ptr, src_type = get_ptr_from_arg(
call.args[1], func, module, builder, local_sym_tab, map_sym_tab, struct_sym_tab
)
# Emit the helper call
result = emit_probe_read_kernel_call(builder, dst_ptr, dst_size, src_ptr)
logger.info(f"Emitted bpf_probe_read_kernel (size={dst_size})")
return result, ir.IntType(64)
@HelperHandlerRegistry.register(
"random",
param_types=[],
@ -711,7 +876,10 @@ def bpf_skb_store_bytes_emitter(
flags_val = get_flags_val(call.args[3], builder, local_sym_tab)
else:
flags_val = 0
flags = ir.Constant(ir.IntType(64), flags_val)
if isinstance(flags_val, int):
flags = ir.Constant(ir.IntType(64), flags_val)
else:
flags = flags_val
fn_type = ir.FunctionType(
ir.IntType(64),
args_signature,
@ -736,6 +904,170 @@ def bpf_skb_store_bytes_emitter(
return result, ir.IntType(64)
@HelperHandlerRegistry.register(
"reserve",
param_types=[ir.IntType(64)],
return_type=ir.PointerType(ir.IntType(8)),
)
def bpf_ringbuf_reserve_emitter(
call,
map_ptr,
module,
builder,
func,
local_sym_tab=None,
struct_sym_tab=None,
map_sym_tab=None,
):
"""
Emit LLVM IR for bpf_ringbuf_reserve helper function call.
Expected call signature: ringbuf.reserve(size)
"""
if len(call.args) != 1:
raise ValueError(
f"ringbuf.reserve expects exactly one argument (size), got {len(call.args)}"
)
size_val = get_int_value_from_arg(
call.args[0],
func,
module,
builder,
local_sym_tab,
map_sym_tab,
struct_sym_tab,
)
map_void_ptr = builder.bitcast(map_ptr, ir.PointerType())
fn_type = ir.FunctionType(
ir.PointerType(ir.IntType(8)),
[ir.PointerType(), ir.IntType(64)],
var_arg=False,
)
fn_ptr_type = ir.PointerType(fn_type)
fn_addr = ir.Constant(ir.IntType(64), BPFHelperID.BPF_RINGBUF_RESERVE.value)
fn_ptr = builder.inttoptr(fn_addr, fn_ptr_type)
result = builder.call(fn_ptr, [map_void_ptr, size_val], tail=False)
return result, ir.PointerType(ir.IntType(8))
@HelperHandlerRegistry.register(
"submit",
param_types=[ir.PointerType(ir.IntType(8)), ir.IntType(64)],
return_type=ir.VoidType(),
)
def bpf_ringbuf_submit_emitter(
call,
map_ptr,
module,
builder,
func,
local_sym_tab=None,
struct_sym_tab=None,
map_sym_tab=None,
):
"""
Emit LLVM IR for bpf_ringbuf_submit helper function call.
Expected call signature: ringbuf.submit(data, flags=0)
"""
if len(call.args) not in (1, 2):
raise ValueError(
f"ringbuf.submit expects 1 or 2 args (data, flags), got {len(call.args)}"
)
data_arg = call.args[0]
flags_arg = call.args[1] if len(call.args) == 2 else None
data_ptr = get_or_create_ptr_from_arg(
func,
module,
data_arg,
builder,
local_sym_tab,
map_sym_tab,
struct_sym_tab,
ir.PointerType(ir.IntType(8)),
)
flags_const = get_flags_val(flags_arg, builder, local_sym_tab)
if isinstance(flags_const, int):
flags_const = ir.Constant(ir.IntType(64), flags_const)
map_void_ptr = builder.bitcast(map_ptr, ir.PointerType())
fn_type = ir.FunctionType(
ir.VoidType(),
[ir.PointerType(), ir.PointerType(), ir.IntType(64)],
var_arg=False,
)
fn_ptr_type = ir.PointerType(fn_type)
fn_addr = ir.Constant(ir.IntType(64), BPFHelperID.BPF_RINGBUF_SUBMIT.value)
fn_ptr = builder.inttoptr(fn_addr, fn_ptr_type)
result = builder.call(fn_ptr, [map_void_ptr, data_ptr, flags_const], tail=False)
return result, None
@HelperHandlerRegistry.register(
"get_stack",
param_types=[ir.PointerType(ir.IntType(8)), ir.IntType(64)],
return_type=ir.IntType(64),
)
def bpf_get_stack_emitter(
call,
map_ptr,
module,
builder,
func,
local_sym_tab=None,
struct_sym_tab=None,
map_sym_tab=None,
):
"""
Emit LLVM IR for bpf_get_stack helper function call.
"""
if len(call.args) not in (1, 2):
raise ValueError(
f"get_stack expects atmost two arguments (buf, flags), got {len(call.args)}"
)
ctx_ptr = func.args[0] # First argument to the function is ctx
buf_arg = call.args[0]
flags_arg = call.args[1] if len(call.args) == 2 else None
buf_ptr, buf_size = get_buffer_ptr_and_size(
buf_arg, builder, local_sym_tab, struct_sym_tab
)
flags_val = get_flags_val(flags_arg, builder, local_sym_tab)
if isinstance(flags_val, int):
flags_val = ir.Constant(ir.IntType(64), flags_val)
buf_void_ptr = builder.bitcast(buf_ptr, ir.PointerType())
fn_type = ir.FunctionType(
ir.IntType(64),
[
ir.PointerType(ir.IntType(8)),
ir.PointerType(),
ir.IntType(64),
ir.IntType(64),
],
var_arg=False,
)
fn_ptr_type = ir.PointerType(fn_type)
fn_addr = ir.Constant(ir.IntType(64), BPFHelperID.BPF_GET_STACK.value)
fn_ptr = builder.inttoptr(fn_addr, fn_ptr_type)
result = builder.call(
fn_ptr,
[ctx_ptr, buf_void_ptr, ir.Constant(ir.IntType(64), buf_size), flags_val],
tail=False,
)
return result, ir.IntType(64)
def handle_helper_call(
call,
module,
@ -790,6 +1122,6 @@ def handle_helper_call(
if not map_sym_tab or map_name not in map_sym_tab:
raise ValueError(f"Map '{map_name}' not found in symbol table")
return invoke_helper(method_name, map_sym_tab[map_name])
return invoke_helper(method_name, map_sym_tab[map_name].sym)
return None

View File

@ -287,7 +287,10 @@ def get_char_array_ptr_and_size(buf_arg, builder, local_sym_tab, struct_sym_tab)
field_type = struct_info.field_type(field_name)
if not _is_char_array(field_type):
raise ValueError("Expected char array field")
logger.info(
"Field is not a char array, falling back to int or ptr detection"
)
return None, 0
struct_ptr = local_sym_tab[var_name].var
field_ptr = struct_info.gep(builder, struct_ptr, field_name)

View File

@ -52,6 +52,11 @@ def skb_store_bytes(offset, from_buf, size, flags=0):
return ctypes.c_int64(0)
def get_stack(buf, flags=0):
"""get the current stack trace"""
return ctypes.c_int64(0)
XDP_ABORTED = ctypes.c_int64(0)
XDP_DROP = ctypes.c_int64(1)
XDP_PASS = ctypes.c_int64(2)

View File

@ -220,11 +220,12 @@ def _prepare_expr_args(expr, func, module, builder, local_sym_tab, struct_sym_ta
"""Evaluate and prepare an expression to use as an arg for bpf_printk."""
# Special case: struct field char array needs pointer to first element
char_array_ptr, _ = get_char_array_ptr_and_size(
expr, builder, local_sym_tab, struct_sym_tab
)
if char_array_ptr:
return char_array_ptr
if isinstance(expr, ast.Attribute):
char_array_ptr, _ = get_char_array_ptr_and_size(
expr, builder, local_sym_tab, struct_sym_tab
)
if char_array_ptr:
return char_array_ptr
# Regular expression evaluation
val, _ = eval_expr(func, module, builder, expr, local_sym_tab, None, struct_sym_tab)

15
pythonbpf/local_symbol.py Normal file
View File

@ -0,0 +1,15 @@
import llvmlite.ir as ir
from dataclasses import dataclass
from typing import Any
@dataclass
class LocalSymbol:
var: ir.AllocaInstr
ir_type: ir.Type
metadata: Any = None
def __iter__(self):
yield self.var
yield self.ir_type
yield self.metadata

View File

@ -1,4 +1,5 @@
from .maps import HashMap, PerfEventArray, RingBuf
from .maps import HashMap, PerfEventArray, RingBuffer
from .maps_pass import maps_proc
from .map_types import BPFMapType
__all__ = ["HashMap", "PerfEventArray", "maps_proc", "RingBuf"]
__all__ = ["HashMap", "PerfEventArray", "maps_proc", "RingBuffer", "BPFMapType"]

View File

@ -1,22 +1,31 @@
import logging
from llvmlite import ir
from pythonbpf.debuginfo import DebugInfoGenerator
from .map_types import BPFMapType
logger: logging.Logger = logging.getLogger(__name__)
def create_map_debug_info(module, map_global, map_name, map_params):
def create_map_debug_info(module, map_global, map_name, map_params, structs_sym_tab):
"""Generate debug info metadata for BPF maps HASH and PERF_EVENT_ARRAY"""
generator = DebugInfoGenerator(module)
logger.info(f"Creating debug info for map {map_name} with params {map_params}")
uint_type = generator.get_uint32_type()
ulong_type = generator.get_uint64_type()
array_type = generator.create_array_type(
uint_type, map_params.get("type", BPFMapType.UNSPEC).value
)
type_ptr = generator.create_pointer_type(array_type, 64)
key_ptr = generator.create_pointer_type(
array_type if "key_size" in map_params else ulong_type, 64
array_type
if "key_size" in map_params
else _get_key_val_dbg_type(map_params.get("key"), generator, structs_sym_tab),
64,
)
value_ptr = generator.create_pointer_type(
array_type if "value_size" in map_params else ulong_type, 64
array_type
if "value_size" in map_params
else _get_key_val_dbg_type(map_params.get("value"), generator, structs_sym_tab),
64,
)
elements_arr = []
@ -64,7 +73,13 @@ def create_map_debug_info(module, map_global, map_name, map_params):
return global_var
def create_ringbuf_debug_info(module, map_global, map_name, map_params):
# TODO: This should not be exposed outside of the module.
# Ideally we should expose a single create_map_debug_info function that handles all map types.
# We can probably use a registry pattern to register different map types and their debug info generators.
# map_params["type"] will be used to determine which generator to use.
def create_ringbuf_debug_info(
module, map_global, map_name, map_params, structs_sym_tab
):
"""Generate debug information metadata for BPF RINGBUF map"""
generator = DebugInfoGenerator(module)
@ -91,3 +106,65 @@ def create_ringbuf_debug_info(module, map_global, map_name, map_params):
)
map_global.set_metadata("dbg", global_var)
return global_var
def _get_key_val_dbg_type(name, generator, structs_sym_tab):
"""Get the debug type for key/value based on type object"""
if not name:
logger.warn("No name provided for key/value type, defaulting to uint64")
return generator.get_uint64_type()
type_obj = structs_sym_tab.get(name)
if type_obj:
return _get_struct_debug_type(type_obj, generator, structs_sym_tab)
# Fallback to basic types
logger.info(f"No struct named {name}, falling back to basic type")
# NOTE: Only handling int and long for now
if name in ["c_int32", "c_uint32"]:
return generator.get_uint32_type()
# Default fallback for now
return generator.get_uint64_type()
def _get_struct_debug_type(struct_obj, generator, structs_sym_tab):
"""Recursively create debug type for struct"""
elements_arr = []
for fld in struct_obj.fields.keys():
fld_type = struct_obj.field_type(fld)
if isinstance(fld_type, ir.IntType):
if fld_type.width == 32:
fld_dbg_type = generator.get_uint32_type()
else:
# NOTE: Assuming 64-bit for all other int types
fld_dbg_type = generator.get_uint64_type()
elif isinstance(fld_type, ir.ArrayType):
# NOTE: Array types have u8 elements only for now
# Debug info generation should fail for other types
elem_type = fld_type.element
if isinstance(elem_type, ir.IntType) and elem_type.width == 8:
char_type = generator.get_uint8_type()
fld_dbg_type = generator.create_array_type(char_type, fld_type.count)
else:
logger.warning(
f"Array element type {str(elem_type)} not supported for debug info, skipping"
)
continue
else:
# NOTE: Only handling int and char arrays for now
logger.warning(
f"Field type {str(fld_type)} not supported for debug info, skipping"
)
continue
member = generator.create_struct_member(
fld, fld_dbg_type, struct_obj.field_size(fld)
)
elements_arr.append(member)
struct_type = generator.create_struct_type(
elements_arr, struct_obj.size, is_distinct=True
)
return struct_type

View File

@ -36,11 +36,14 @@ class PerfEventArray:
pass # Placeholder for output method
class RingBuf:
class RingBuffer:
def __init__(self, max_entries):
self.max_entries = max_entries
def reserve(self, size: int, flags=0):
def output(self, data, flags=0):
pass
def reserve(self, size: int):
if size > self.max_entries:
raise ValueError("size cannot be greater than set maximum entries")
return 0
@ -48,4 +51,7 @@ class RingBuf:
def submit(self, data, flags=0):
pass
def discard(self, data, flags=0):
pass
# add discard, output and also give names to flags and stuff

View File

@ -3,7 +3,7 @@ import logging
from logging import Logger
from llvmlite import ir
from .maps_utils import MapProcessorRegistry
from .maps_utils import MapProcessorRegistry, MapSymbol
from .map_types import BPFMapType
from .map_debug_info import create_map_debug_info, create_ringbuf_debug_info
from pythonbpf.expr.vmlinux_registry import VmlinuxHandlerRegistry
@ -12,13 +12,15 @@ from pythonbpf.expr.vmlinux_registry import VmlinuxHandlerRegistry
logger: Logger = logging.getLogger(__name__)
def maps_proc(tree, module, chunks):
def maps_proc(tree, module, chunks, structs_sym_tab):
"""Process all functions decorated with @map to find BPF maps"""
map_sym_tab = {}
for func_node in chunks:
if is_map(func_node):
logger.info(f"Found BPF map: {func_node.name}")
map_sym_tab[func_node.name] = process_bpf_map(func_node, module)
map_sym_tab[func_node.name] = process_bpf_map(
func_node, module, structs_sym_tab
)
return map_sym_tab
@ -46,7 +48,7 @@ def create_bpf_map(module, map_name, map_params):
map_global.align = 8
logger.info(f"Created BPF map: {map_name} with params {map_params}")
return map_global
return MapSymbol(type=map_params["type"], sym=map_global, params=map_params)
def _parse_map_params(rval, expected_args=None):
@ -60,7 +62,8 @@ def _parse_map_params(rval, expected_args=None):
if i < len(rval.args):
arg = rval.args[i]
if isinstance(arg, ast.Name):
params[arg_name] = arg.id
result = _get_vmlinux_enum(handler, arg.id)
params[arg_name] = result if result is not None else arg.id
elif isinstance(arg, ast.Constant):
params[arg_name] = arg.value
@ -68,33 +71,48 @@ def _parse_map_params(rval, expected_args=None):
for keyword in rval.keywords:
if isinstance(keyword.value, ast.Name):
name = keyword.value.id
if handler and handler.is_vmlinux_enum(name):
result = handler.get_vmlinux_enum_value(name)
params[keyword.arg] = result if result is not None else name
else:
params[keyword.arg] = name
result = _get_vmlinux_enum(handler, name)
params[keyword.arg] = result if result is not None else name
elif isinstance(keyword.value, ast.Constant):
params[keyword.arg] = keyword.value.value
return params
@MapProcessorRegistry.register("RingBuf")
def process_ringbuf_map(map_name, rval, module):
def _get_vmlinux_enum(handler, name):
if handler and handler.is_vmlinux_enum(name):
return handler.get_vmlinux_enum_value(name)
@MapProcessorRegistry.register("RingBuffer")
def process_ringbuf_map(map_name, rval, module, structs_sym_tab):
"""Process a BPF_RINGBUF map declaration"""
logger.info(f"Processing Ringbuf: {map_name}")
map_params = _parse_map_params(rval, expected_args=["max_entries"])
map_params["type"] = BPFMapType.RINGBUF
# NOTE: constraints borrowed from https://docs.ebpf.io/linux/map-type/BPF_MAP_TYPE_RINGBUF/
max_entries = map_params.get("max_entries")
if (
not isinstance(max_entries, int)
or max_entries < 4096
or (max_entries & (max_entries - 1)) != 0
):
raise ValueError(
"Ringbuf max_entries must be a power of two greater than or equal to the page size (4096)"
)
logger.info(f"Ringbuf map parameters: {map_params}")
map_global = create_bpf_map(module, map_name, map_params)
create_ringbuf_debug_info(module, map_global, map_name, map_params)
create_ringbuf_debug_info(
module, map_global.sym, map_name, map_params, structs_sym_tab
)
return map_global
@MapProcessorRegistry.register("HashMap")
def process_hash_map(map_name, rval, module):
def process_hash_map(map_name, rval, module, structs_sym_tab):
"""Process a BPF_HASH map declaration"""
logger.info(f"Processing HashMap: {map_name}")
map_params = _parse_map_params(rval, expected_args=["key", "value", "max_entries"])
@ -103,12 +121,12 @@ def process_hash_map(map_name, rval, module):
logger.info(f"Map parameters: {map_params}")
map_global = create_bpf_map(module, map_name, map_params)
# Generate debug info for BTF
create_map_debug_info(module, map_global, map_name, map_params)
create_map_debug_info(module, map_global.sym, map_name, map_params, structs_sym_tab)
return map_global
@MapProcessorRegistry.register("PerfEventArray")
def process_perf_event_map(map_name, rval, module):
def process_perf_event_map(map_name, rval, module, structs_sym_tab):
"""Process a BPF_PERF_EVENT_ARRAY map declaration"""
logger.info(f"Processing PerfEventArray: {map_name}")
map_params = _parse_map_params(rval, expected_args=["key_size", "value_size"])
@ -117,11 +135,11 @@ def process_perf_event_map(map_name, rval, module):
logger.info(f"Map parameters: {map_params}")
map_global = create_bpf_map(module, map_name, map_params)
# Generate debug info for BTF
create_map_debug_info(module, map_global, map_name, map_params)
create_map_debug_info(module, map_global.sym, map_name, map_params)
return map_global
def process_bpf_map(func_node, module):
def process_bpf_map(func_node, module, structs_sym_tab):
"""Process a BPF map (a function decorated with @map)"""
map_name = func_node.name
logger.info(f"Processing BPF map: {map_name}")
@ -140,7 +158,7 @@ def process_bpf_map(func_node, module):
if isinstance(rval, ast.Call) and isinstance(rval.func, ast.Name):
handler = MapProcessorRegistry.get_processor(rval.func.id)
if handler:
return handler(map_name, rval, module)
return handler(map_name, rval, module, structs_sym_tab)
else:
logger.warning(f"Unknown map type {rval.func.id}, defaulting to HashMap")
return process_hash_map(map_name, rval, module)

View File

@ -1,5 +1,17 @@
from collections.abc import Callable
from dataclasses import dataclass
from llvmlite import ir
from typing import Any
from .map_types import BPFMapType
@dataclass
class MapSymbol:
"""Class representing a symbol on the map"""
type: BPFMapType
sym: ir.GlobalVariable
params: dict[str, Any] | None = None
class MapProcessorRegistry:

View File

@ -13,6 +13,10 @@ mapping = {
"c_float": ir.FloatType(),
"c_double": ir.DoubleType(),
"c_void_p": ir.IntType(64),
"c_long": ir.IntType(64),
"c_ulong": ir.IntType(64),
"c_longlong": ir.IntType(64),
"c_uint": ir.IntType(32),
# Not so sure about this one
"str": ir.PointerType(ir.IntType(8)),
}

View File

@ -6,7 +6,6 @@ import llvmlite.ir as ir
from pythonbpf.vmlinux_parser.dependency_node import Field
@dataclass
class AssignmentType(Enum):
CONSTANT = auto()
STRUCT = auto()
@ -34,3 +33,4 @@ class AssignmentInfo:
# Value is a tuple that contains the global variable representing that field
# along with all the information about that field as a Field type.
members: Optional[Dict[str, tuple[ir.GlobalVariable, Field]]] # For structs.
debug_info: Any

View File

@ -16,6 +16,33 @@ def get_module_symbols(module_name: str):
return [name for name in dir(imported_module)], imported_module
def unwrap_pointer_type(type_obj: Any) -> Any:
"""
Recursively unwrap all pointer layers to get the base type.
This handles multiply nested pointers like LP_LP_struct_attribute_group
and returns the base type (struct_attribute_group).
Stops unwrapping when reaching a non-pointer type (one without _type_ attribute).
Args:
type_obj: The type object to unwrap
Returns:
The base type after unwrapping all pointer layers
"""
current_type = type_obj
# Keep unwrapping while it's a pointer/array type (has _type_)
# But stop if _type_ is just a string or basic type marker
while hasattr(current_type, "_type_"):
next_type = current_type._type_
# Stop if _type_ is a string (like 'c' for c_char)
if isinstance(next_type, str):
break
current_type = next_type
return current_type
def process_vmlinux_class(
node,
llvm_module,
@ -158,13 +185,90 @@ def process_vmlinux_post_ast(
if hasattr(elem_type, "_length_") and is_complex_type:
type_length = elem_type._length_
if containing_type.__module__ == "vmlinux":
new_dep_node.add_dependent(
elem_type._type_.__name__
if hasattr(elem_type._type_, "__name__")
else str(elem_type._type_)
# Unwrap all pointer layers to get the base type for dependency tracking
base_type = unwrap_pointer_type(elem_type)
base_type_module = getattr(base_type, "__module__", None)
if base_type_module == "vmlinux":
base_type_name = (
base_type.__name__
if hasattr(base_type, "__name__")
else str(base_type)
)
# ONLY add vmlinux types as dependencies
new_dep_node.add_dependent(base_type_name)
logger.debug(
f"{containing_type} containing type of parent {elem_name} with {elem_type} and ctype {ctype_complex_type} and length {type_length}"
)
new_dep_node.set_field_containing_type(
elem_name, containing_type
)
new_dep_node.set_field_type_size(elem_name, type_length)
new_dep_node.set_field_ctype_complex_type(
elem_name, ctype_complex_type
)
new_dep_node.set_field_type(elem_name, elem_type)
# Check the containing_type module to decide whether to recurse
containing_type_module = getattr(
containing_type, "__module__", None
)
if containing_type_module == "vmlinux":
# Also unwrap containing_type to get base type name
base_containing_type = unwrap_pointer_type(
containing_type
)
containing_type_name = (
base_containing_type.__name__
if hasattr(base_containing_type, "__name__")
else str(base_containing_type)
)
# Check for self-reference or already processed
if containing_type_name == current_symbol_name:
# Self-referential pointer
logger.debug(
f"Self-referential pointer in {current_symbol_name}.{elem_name}"
)
new_dep_node.set_field_ready(elem_name, True)
elif handler.has_node(containing_type_name):
# Already processed
logger.debug(
f"Reusing already processed {containing_type_name}"
)
new_dep_node.set_field_ready(elem_name, True)
else:
# Process recursively - use base containing type, not the pointer wrapper
new_dep_node.add_dependent(containing_type_name)
process_vmlinux_post_ast(
base_containing_type,
llvm_handler,
handler,
processing_stack,
)
new_dep_node.set_field_ready(elem_name, True)
elif (
containing_type_module == ctypes.__name__
or containing_type_module is None
):
logger.debug(
f"Processing ctype internal{containing_type}"
)
new_dep_node.set_field_ready(elem_name, True)
else:
raise TypeError(
f"Module not supported in recursive resolution: {containing_type_module}"
)
elif (
base_type_module == ctypes.__name__
or base_type_module is None
):
# Handle ctypes or types with no module (like some internal ctypes types)
# DO NOT add ctypes as dependencies - just set field metadata and mark ready
logger.debug(
f"Base type {base_type} is ctypes - NOT adding as dependency, just processing field"
)
elif containing_type.__module__ == ctypes.__name__:
if isinstance(elem_type, type):
if issubclass(elem_type, ctypes.Array):
ctype_complex_type = ctypes.Array
@ -176,57 +280,20 @@ def process_vmlinux_post_ast(
)
else:
raise TypeError("Unsupported ctypes subclass")
else:
raise ImportError(
f"Unsupported module of {containing_type}"
)
logger.debug(
f"{containing_type} containing type of parent {elem_name} with {elem_type} and ctype {ctype_complex_type} and length {type_length}"
)
new_dep_node.set_field_containing_type(
elem_name, containing_type
)
new_dep_node.set_field_type_size(elem_name, type_length)
new_dep_node.set_field_ctype_complex_type(
elem_name, ctype_complex_type
)
new_dep_node.set_field_type(elem_name, elem_type)
if containing_type.__module__ == "vmlinux":
containing_type_name = (
containing_type.__name__
if hasattr(containing_type, "__name__")
else str(containing_type)
)
# Check for self-reference or already processed
if containing_type_name == current_symbol_name:
# Self-referential pointer
logger.debug(
f"Self-referential pointer in {current_symbol_name}.{elem_name}"
)
new_dep_node.set_field_ready(elem_name, True)
elif handler.has_node(containing_type_name):
# Already processed
logger.debug(
f"Reusing already processed {containing_type_name}"
)
new_dep_node.set_field_ready(elem_name, True)
else:
# Process recursively - THIS WAS MISSING
new_dep_node.add_dependent(containing_type_name)
process_vmlinux_post_ast(
containing_type,
llvm_handler,
handler,
processing_stack,
)
new_dep_node.set_field_ready(elem_name, True)
elif containing_type.__module__ == ctypes.__name__:
logger.debug(f"Processing ctype internal{containing_type}")
# Set field metadata but DO NOT add dependency or recurse
new_dep_node.set_field_containing_type(
elem_name, containing_type
)
new_dep_node.set_field_type_size(elem_name, type_length)
new_dep_node.set_field_ctype_complex_type(
elem_name, ctype_complex_type
)
new_dep_node.set_field_type(elem_name, elem_type)
new_dep_node.set_field_ready(elem_name, True)
else:
raise TypeError(
"Module not supported in recursive resolution"
raise ImportError(
f"Unsupported module of {base_type}: {base_type_module}"
)
else:
new_dep_node.add_dependent(
@ -245,9 +312,12 @@ def process_vmlinux_post_ast(
raise ValueError(
f"{elem_name} with type {elem_type} from module {module_name} not supported in recursive resolver"
)
elif module_name == ctypes.__name__ or module_name is None:
# Handle ctypes types - these don't need processing, just return
logger.debug(f"Skipping ctypes type {current_symbol_name}")
return True
else:
raise ImportError("UNSUPPORTED Module")
raise ImportError(f"UNSUPPORTED Module {module_name}")
logger.info(
f"{current_symbol_name} processed and handler readiness {handler.is_ready}"

View File

@ -11,7 +11,9 @@ from .class_handler import process_vmlinux_class
logger = logging.getLogger(__name__)
def detect_import_statement(tree: ast.AST) -> list[tuple[str, ast.ImportFrom]]:
def detect_import_statement(
tree: ast.AST,
) -> list[tuple[str, ast.ImportFrom, str, str]]:
"""
Parse AST and detect import statements from vmlinux.
@ -25,7 +27,7 @@ def detect_import_statement(tree: ast.AST) -> list[tuple[str, ast.ImportFrom]]:
List of tuples containing (module_name, imported_item) for each vmlinux import
Raises:
SyntaxError: If multiple imports from vmlinux are attempted or import * is used
SyntaxError: If import * is used
"""
vmlinux_imports = []
@ -40,28 +42,19 @@ def detect_import_statement(tree: ast.AST) -> list[tuple[str, ast.ImportFrom]]:
"Please import specific types explicitly."
)
# Check for multiple imports: from vmlinux import A, B, C
if len(node.names) > 1:
imported_names = [alias.name for alias in node.names]
raise SyntaxError(
f"Multiple imports from vmlinux are not supported. "
f"Found: {', '.join(imported_names)}. "
f"Please use separate import statements for each type."
)
# Check if no specific import is specified (should not happen with valid Python)
if len(node.names) == 0:
raise SyntaxError(
"Import from vmlinux must specify at least one type."
)
# Valid single import
# Support multiple imports: from vmlinux import A, B, C
for alias in node.names:
import_name = alias.name
# Use alias if provided, otherwise use the original name (commented)
# as_name = alias.asname if alias.asname else alias.name
vmlinux_imports.append(("vmlinux", node))
logger.info(f"Found vmlinux import: {import_name}")
# Use alias if provided, otherwise use the original name
as_name = alias.asname if alias.asname else alias.name
vmlinux_imports.append(("vmlinux", node, import_name, as_name))
logger.info(f"Found vmlinux import: {import_name} as {as_name}")
# Handle "import vmlinux" statements (not typical but should be rejected)
elif isinstance(node, ast.Import):
@ -86,57 +79,54 @@ def vmlinux_proc(tree: ast.AST, module):
if not import_statements:
logger.info("No vmlinux imports found")
return
return None
# Import vmlinux module directly
try:
vmlinux_mod = importlib.import_module("vmlinux")
except ImportError:
logger.warning("Could not import vmlinux module")
return
return None
source_file = inspect.getsourcefile(vmlinux_mod)
if source_file is None:
logger.warning("Cannot find source for vmlinux module")
return
return None
with open(source_file, "r") as f:
mod_ast = ast.parse(f.read(), filename=source_file)
for import_mod, import_node in import_statements:
for alias in import_node.names:
imported_name = alias.name
found = False
for mod_node in mod_ast.body:
if (
isinstance(mod_node, ast.ClassDef)
and mod_node.name == imported_name
):
process_vmlinux_class(mod_node, module, handler)
found = True
break
if isinstance(mod_node, ast.Assign):
for target in mod_node.targets:
if isinstance(target, ast.Name) and target.id == imported_name:
process_vmlinux_assign(mod_node, module, assignments)
found = True
break
if found:
break
if not found:
logger.info(
f"{imported_name} not found as ClassDef or Assign in vmlinux"
)
for import_mod, import_node, imported_name, as_name in import_statements:
found = False
for mod_node in mod_ast.body:
if isinstance(mod_node, ast.ClassDef) and mod_node.name == imported_name:
process_vmlinux_class(mod_node, module, handler)
found = True
break
if isinstance(mod_node, ast.Assign):
for target in mod_node.targets:
if isinstance(target, ast.Name) and target.id == imported_name:
process_vmlinux_assign(mod_node, module, assignments, as_name)
found = True
break
if found:
break
if not found:
logger.info(f"{imported_name} not found as ClassDef or Assign in vmlinux")
IRGenerator(module, handler, assignments)
return assignments
def process_vmlinux_assign(node, module, assignments: dict[str, AssignmentInfo]):
def process_vmlinux_assign(
node, module, assignments: dict[str, AssignmentInfo], target_name=None
):
"""Process assignments from vmlinux module."""
# Only handle single-target assignments
if len(node.targets) == 1 and isinstance(node.targets[0], ast.Name):
target_name = node.targets[0].id
# Use provided target_name (for aliased imports) or fall back to original name
if target_name is None:
target_name = node.targets[0].id
# Handle constant value assignments
if isinstance(node.value, ast.Constant):
@ -148,6 +138,7 @@ def process_vmlinux_assign(node, module, assignments: dict[str, AssignmentInfo])
pointer_level=None,
signature=None,
members=None,
debug_info=None,
)
logger.info(
f"Added assignment: {target_name} = {node.value.value!r} of type {type(node.value.value)}"

View File

@ -21,7 +21,7 @@ def debug_info_generation(
generated_debug_info: List of tuples (struct, debug_info) to track generated debug info
Returns:
The generated global variable debug info
The generated global variable debug info, or None for unsupported types
"""
# Set up debug info generator
generator = DebugInfoGenerator(llvm_module)
@ -31,23 +31,42 @@ def debug_info_generation(
if existing_struct.name == struct.name:
return debug_info
# Check if this is a union (not supported yet)
if not struct.name.startswith("struct_"):
logger.warning(f"Skipping debug info generation for union: {struct.name}")
# Create a minimal forward declaration for unions
union_type = generator.create_struct_type(
[], struct.__sizeof__() * 8, is_distinct=True
)
return union_type
# Process all fields and create members for the struct
members = []
for field_name, field in struct.fields.items():
# Get appropriate debug type for this field
field_type = _get_field_debug_type(
field_name, field, generator, struct, generated_debug_info
)
# Create struct member with proper offset
member = generator.create_struct_member_vmlinux(
field_name, field_type, field.offset * 8
)
members.append(member)
if struct.name.startswith("struct_"):
struct_name = struct.name.removeprefix("struct_")
else:
raise ValueError("Unions are not supported in the current version")
sorted_fields = sorted(struct.fields.items(), key=lambda item: item[1].offset)
for field_name, field in sorted_fields:
try:
# Get appropriate debug type for this field
field_type = _get_field_debug_type(
field_name, field, generator, struct, generated_debug_info
)
# Ensure field_type is a tuple
if not isinstance(field_type, tuple) or len(field_type) != 2:
logger.error(f"Invalid field_type for {field_name}: {field_type}")
continue
# Create struct member with proper offset
member = generator.create_struct_member_vmlinux(
field_name, field_type, field.offset * 8
)
members.append(member)
except Exception as e:
logger.error(f"Failed to process field {field_name} in {struct.name}: {e}")
continue
struct_name = struct.name.removeprefix("struct_")
# Create struct type with all members
struct_type = generator.create_struct_type_with_name(
struct_name, members, struct.__sizeof__() * 8, is_distinct=True
@ -74,11 +93,19 @@ def _get_field_debug_type(
generated_debug_info: List of already generated debug info
Returns:
The debug info type for this field
A tuple of (debug_type, size_in_bits)
"""
# Handle complex types (arrays, pointers)
# Handle complex types (arrays, pointers, function pointers)
if field.ctype_complex_type is not None:
if issubclass(field.ctype_complex_type, ctypes.Array):
# Handle function pointer types (CFUNCTYPE)
if callable(field.ctype_complex_type):
# Function pointers are represented as void pointers
logger.warning(
f"Field {field_name} is a function pointer, using void pointer"
)
void_ptr = generator.create_pointer_type(None, 64)
return void_ptr, 64
elif issubclass(field.ctype_complex_type, ctypes.Array):
# Handle array types
element_type, base_type_size = _get_basic_debug_type(
field.containing_type, generator
@ -100,11 +127,13 @@ def _get_field_debug_type(
for existing_struct, debug_info in generated_debug_info:
if existing_struct.name == struct_name:
# Use existing debug info
return debug_info, existing_struct.__sizeof__()
return debug_info, existing_struct.__sizeof__() * 8
# If not found, create a forward declaration
# This will be completed when the actual struct is processed
logger.warning("Forward declaration in struct created")
logger.info(
f"Forward declaration created for {struct_name} in {parent_struct.name}"
)
forward_type = generator.create_struct_type([], 0, is_distinct=True)
return forward_type, 0

View File

@ -11,6 +11,10 @@ logger = logging.getLogger(__name__)
class IRGenerator:
# This field keeps track of the non_struct names to avoid duplicate name errors.
type_number = 0
unprocessed_store: list[str] = []
# get the assignments dict and add this stuff to it.
def __init__(self, llvm_module, handler: DependencyHandler, assignments):
self.llvm_module = llvm_module
@ -73,9 +77,8 @@ class IRGenerator:
)
# Generate IR first to populate field names
self.generated_debug_info.append(
(struct, self.gen_ir(struct, self.generated_debug_info))
)
struct_debug_info = self.gen_ir(struct, self.generated_debug_info)
self.generated_debug_info.append((struct, struct_debug_info))
# Fill the assignments dictionary with struct information
if struct.name not in self.assignments:
@ -105,6 +108,7 @@ class IRGenerator:
pointer_level=None,
signature=None,
members=members_dict,
debug_info=struct_debug_info,
)
logger.info(f"Added struct assignment info for {struct.name}")
@ -129,7 +133,19 @@ class IRGenerator:
for field_name, field in struct.fields.items():
# does not take arrays and similar types into consideration yet.
if field.ctype_complex_type is not None and issubclass(
if callable(field.ctype_complex_type):
# Function pointer case - generate a simple field accessor
field_co_re_name, returned = self._struct_name_generator(
struct, field, field_index
)
field_index += 1
globvar = ir.GlobalVariable(
self.llvm_module, ir.IntType(64), name=field_co_re_name
)
globvar.linkage = "external"
globvar.set_metadata("llvm.preserve.access.index", debug_info)
self.generated_field_names[struct.name][field_name] = globvar
elif field.ctype_complex_type is not None and issubclass(
field.ctype_complex_type, ctypes.Array
):
array_size = field.type_size
@ -137,7 +153,7 @@ class IRGenerator:
if containing_type.__module__ == ctypes.__name__:
containing_type_size = ctypes.sizeof(containing_type)
if array_size == 0:
field_co_re_name = self._struct_name_generator(
field_co_re_name, returned = self._struct_name_generator(
struct, field, field_index, True, 0, containing_type_size
)
globvar = ir.GlobalVariable(
@ -149,7 +165,7 @@ class IRGenerator:
field_index += 1
continue
for i in range(0, array_size):
field_co_re_name = self._struct_name_generator(
field_co_re_name, returned = self._struct_name_generator(
struct, field, field_index, True, i, containing_type_size
)
globvar = ir.GlobalVariable(
@ -163,12 +179,28 @@ class IRGenerator:
array_size = field.type_size
containing_type = field.containing_type
if containing_type.__module__ == "vmlinux":
containing_type_size = self.handler[
containing_type.__name__
].current_offset
for i in range(0, array_size):
field_co_re_name = self._struct_name_generator(
struct, field, field_index, True, i, containing_type_size
# Unwrap all pointer layers to get the base struct type
base_containing_type = containing_type
while hasattr(base_containing_type, "_type_"):
next_type = base_containing_type._type_
# Stop if _type_ is a string (like 'c' for c_char)
# TODO: stacked pointers not handl;ing ctypes check here as well
if isinstance(next_type, str):
break
base_containing_type = next_type
# Get the base struct name
base_struct_name = (
base_containing_type.__name__
if hasattr(base_containing_type, "__name__")
else str(base_containing_type)
)
# Look up the size using the base struct name
containing_type_size = self.handler[base_struct_name].current_offset
if array_size == 0:
field_co_re_name, returned = self._struct_name_generator(
struct, field, field_index, True, 0, containing_type_size
)
globvar = ir.GlobalVariable(
self.llvm_module, ir.IntType(64), name=field_co_re_name
@ -176,9 +208,30 @@ class IRGenerator:
globvar.linkage = "external"
globvar.set_metadata("llvm.preserve.access.index", debug_info)
self.generated_field_names[struct.name][field_name] = globvar
field_index += 1
field_index += 1
else:
for i in range(0, array_size):
field_co_re_name, returned = self._struct_name_generator(
struct,
field,
field_index,
True,
i,
containing_type_size,
)
globvar = ir.GlobalVariable(
self.llvm_module, ir.IntType(64), name=field_co_re_name
)
globvar.linkage = "external"
globvar.set_metadata(
"llvm.preserve.access.index", debug_info
)
self.generated_field_names[struct.name][field_name] = (
globvar
)
field_index += 1
else:
field_co_re_name = self._struct_name_generator(
field_co_re_name, returned = self._struct_name_generator(
struct, field, field_index
)
field_index += 1
@ -198,7 +251,7 @@ class IRGenerator:
is_indexed: bool = False,
index: int = 0,
containing_type_size: int = 0,
) -> str:
) -> tuple[str, bool]:
# TODO: Does not support Unions as well as recursive pointer and array type naming
if is_indexed:
name = (
@ -208,7 +261,7 @@ class IRGenerator:
+ "$"
+ f"0:{field_index}:{index}"
)
return name
return name, True
elif struct.name.startswith("struct_"):
name = (
"llvm."
@ -217,9 +270,18 @@ class IRGenerator:
+ "$"
+ f"0:{field_index}"
)
return name
return name, True
else:
print(self.handler[struct.name])
raise TypeError(
"Name generation cannot occur due to type name not starting with struct"
logger.warning(
"Blindly handling non-struct type to avoid type errors in vmlinux IR generation. Possibly a union."
)
self.type_number += 1
unprocessed_type = "unprocessed_type_" + str(self.handler[struct.name].name)
if self.unprocessed_store.__contains__(unprocessed_type):
return unprocessed_type + "_" + str(self.type_number), False
else:
self.unprocessed_store.append(unprocessed_type)
return unprocessed_type, False
# raise TypeError(
# "Name generation cannot occur due to type name not starting with struct"
# )

View File

@ -1,6 +1,9 @@
import logging
from typing import Any
import ctypes
from llvmlite import ir
from pythonbpf.local_symbol import LocalSymbol
from pythonbpf.vmlinux_parser.assignment_info import AssignmentType
logger = logging.getLogger(__name__)
@ -36,20 +39,39 @@ class VmlinuxHandler:
"""Check if name is a vmlinux enum constant"""
return (
name in self.vmlinux_symtab
and self.vmlinux_symtab[name]["value_type"] == AssignmentType.CONSTANT
and self.vmlinux_symtab[name].value_type == AssignmentType.CONSTANT
)
def get_struct_debug_info(self, name: str) -> Any:
if (
name in self.vmlinux_symtab
and self.vmlinux_symtab[name].value_type == AssignmentType.STRUCT
):
return self.vmlinux_symtab[name].debug_info
else:
raise ValueError(f"{name} is not a vmlinux struct type")
def get_vmlinux_struct_type(self, name):
"""Check if name is a vmlinux struct type"""
if (
name in self.vmlinux_symtab
and self.vmlinux_symtab[name].value_type == AssignmentType.STRUCT
):
return self.vmlinux_symtab[name].python_type
else:
raise ValueError(f"{name} is not a vmlinux struct type")
def is_vmlinux_struct(self, name):
"""Check if name is a vmlinux struct"""
return (
name in self.vmlinux_symtab
and self.vmlinux_symtab[name]["value_type"] == AssignmentType.STRUCT
and self.vmlinux_symtab[name].value_type == AssignmentType.STRUCT
)
def handle_vmlinux_enum(self, name):
"""Handle vmlinux enum constants by returning LLVM IR constants"""
if self.is_vmlinux_enum(name):
value = self.vmlinux_symtab[name]["value"]
value = self.vmlinux_symtab[name].value
logger.info(f"Resolving vmlinux enum {name} = {value}")
return ir.Constant(ir.IntType(64), value), ir.IntType(64)
return None
@ -57,34 +79,300 @@ class VmlinuxHandler:
def get_vmlinux_enum_value(self, name):
"""Handle vmlinux enum constants by returning LLVM IR constants"""
if self.is_vmlinux_enum(name):
value = self.vmlinux_symtab[name]["value"]
value = self.vmlinux_symtab[name].value
logger.info(f"The value of vmlinux enum {name} = {value}")
return value
return None
def handle_vmlinux_struct(self, struct_name, module, builder):
"""Handle vmlinux struct initializations"""
if self.is_vmlinux_struct(struct_name):
# TODO: Implement core-specific struct handling
# This will be more complex and depends on the BTF information
logger.info(f"Handling vmlinux struct {struct_name}")
# Return struct type and allocated pointer
# This is a stub, actual implementation will be more complex
return None
return None
def handle_vmlinux_struct_field(
self, struct_var_name, field_name, module, builder, local_sym_tab
):
"""Handle access to vmlinux struct fields"""
# Check if it's a variable of vmlinux struct type
if struct_var_name in local_sym_tab:
var_info = local_sym_tab[struct_var_name] # noqa: F841
# Need to check if this variable is a vmlinux struct
# This will depend on how you track vmlinux struct types in your symbol table
var_info: LocalSymbol = local_sym_tab[struct_var_name]
logger.info(
f"Attempting to access field {field_name} of possible vmlinux struct {struct_var_name}"
)
# Return pointer to field and field type
return None
return None
python_type: type = var_info.metadata
# Check if this is a context field (ctx) or a cast struct
is_context_field = var_info.var is None
if is_context_field:
# Handle context field access (original behavior)
struct_name = python_type.__name__
globvar_ir, field_data = self.get_field_type(struct_name, field_name)
builder.function.args[0].type = ir.PointerType(ir.IntType(8))
field_ptr = self.load_ctx_field(
builder,
builder.function.args[0],
globvar_ir,
field_data,
struct_name,
)
return field_ptr, field_data
else:
# Handle cast struct field access
struct_name = python_type.__name__
globvar_ir, field_data = self.get_field_type(struct_name, field_name)
# Handle cast struct field access (use bpf_probe_read_kernel)
# Load the struct pointer from the local variable
struct_ptr = builder.load(var_info.var)
# Use bpf_probe_read_kernel for non-context struct field access
field_value = self.load_struct_field(
builder, struct_ptr, globvar_ir, field_data, struct_name
)
# Return field value and field type
return field_value, field_data
else:
raise RuntimeError("Variable accessed not found in symbol table")
@staticmethod
def load_struct_field(
builder, struct_ptr_int, offset_global, field_data, struct_name=None
):
"""
Generate LLVM IR to load a field from a regular (non-context) struct using bpf_probe_read_kernel.
Args:
builder: llvmlite IRBuilder instance
struct_ptr_int: The struct pointer as an i64 value (already loaded from alloca)
offset_global: Global variable containing the field offset (i64)
field_data: contains data about the field
struct_name: Name of the struct being accessed (optional)
Returns:
The loaded value
"""
# Load the offset value
offset = builder.load(offset_global)
# Convert i64 to pointer type (BPF stores pointers as i64)
i8_ptr_type = ir.PointerType(ir.IntType(8))
struct_ptr = builder.inttoptr(struct_ptr_int, i8_ptr_type)
# GEP with offset to get field pointer
field_ptr = builder.gep(
struct_ptr,
[offset],
inbounds=False,
)
# Determine the appropriate field size based on field information
field_size_bytes = 8 # Default to 8 bytes (64-bit)
int_width = 64 # Default to 64-bit
needs_zext = False
if field_data is not None:
# Try to determine the size from field metadata
if field_data.type.__module__ == ctypes.__name__:
try:
field_size_bytes = ctypes.sizeof(field_data.type)
field_size_bits = field_size_bytes * 8
if field_size_bits in [8, 16, 32, 64]:
int_width = field_size_bits
logger.info(
f"Determined field size: {int_width} bits ({field_size_bytes} bytes)"
)
# Special handling for struct_xdp_md i32 fields
if struct_name == "struct_xdp_md" and int_width == 32:
needs_zext = True
logger.info(
"struct_xdp_md i32 field detected, will zero-extend to i64"
)
else:
logger.warning(
f"Unusual field size {field_size_bits} bits, using default 64"
)
except Exception as e:
logger.warning(
f"Could not determine field size: {e}, using default 64"
)
elif field_data.type.__module__ == "vmlinux":
# For pointers to structs or complex vmlinux types
if field_data.ctype_complex_type is not None and issubclass(
field_data.ctype_complex_type, ctypes._Pointer
):
int_width = 64 # Pointers are always 64-bit
field_size_bytes = 8
logger.info("Field is a pointer type, using 64 bits")
else:
logger.warning("Complex vmlinux field type, using default 64 bits")
# Allocate local storage for the field value
local_storage = builder.alloca(ir.IntType(int_width))
local_storage_i8_ptr = builder.bitcast(local_storage, i8_ptr_type)
# Use bpf_probe_read_kernel to safely read the field
# This generates:
# %gep = getelementptr i8, ptr %struct_ptr, i64 %offset (already done above as field_ptr)
# %passed = tail call ptr @llvm.bpf.passthrough.p0.p0(i32 2, ptr %gep)
# %result = call i64 inttoptr (i64 113 to ptr)(ptr %local_storage, i32 %size, ptr %passed)
from pythonbpf.helper import emit_probe_read_kernel_call
emit_probe_read_kernel_call(
builder, local_storage_i8_ptr, field_size_bytes, field_ptr
)
# Load the value from local storage
value = builder.load(local_storage)
# Zero-extend i32 to i64 if needed
if needs_zext:
value = builder.zext(value, ir.IntType(64))
logger.info("Zero-extended i32 value to i64")
return value
@staticmethod
def load_ctx_field(builder, ctx_arg, offset_global, field_data, struct_name=None):
"""
Generate LLVM IR to load a field from BPF context using offset.
Args:
builder: llvmlite IRBuilder instance
ctx_arg: The context pointer argument (ptr/i8*)
offset_global: Global variable containing the field offset (i64)
field_data: contains data about the field
struct_name: Name of the struct being accessed (optional)
Returns:
The loaded value (i64 register or appropriately sized)
"""
# Load the offset value
offset = builder.load(offset_global)
# Ensure ctx_arg is treated as i8* (byte pointer)
i8_ptr_type = ir.PointerType()
# Cast ctx_arg to i8* if it isn't already
if str(ctx_arg.type) != str(i8_ptr_type):
ctx_i8_ptr = builder.bitcast(ctx_arg, i8_ptr_type)
else:
ctx_i8_ptr = ctx_arg
# GEP with explicit type - this is the key fix
field_ptr = builder.gep(
ctx_i8_ptr,
[offset],
inbounds=False,
)
# Get or declare the BPF passthrough intrinsic
module = builder.function.module
try:
passthrough_fn = module.globals.get("llvm.bpf.passthrough.p0.p0")
if passthrough_fn is None:
raise KeyError
except (KeyError, AttributeError):
passthrough_type = ir.FunctionType(
i8_ptr_type,
[ir.IntType(32), i8_ptr_type],
)
passthrough_fn = ir.Function(
module,
passthrough_type,
name="llvm.bpf.passthrough.p0.p0",
)
# Call passthrough to satisfy BPF verifier
verified_ptr = builder.call(
passthrough_fn, [ir.Constant(ir.IntType(32), 0), field_ptr], tail=True
)
# Determine the appropriate IR type based on field information
int_width = 64 # Default to 64-bit
needs_zext = False # Track if we need zero-extension for xdp_md
if field_data is not None:
# Try to determine the size from field metadata
if field_data.type.__module__ == ctypes.__name__:
try:
field_size_bytes = ctypes.sizeof(field_data.type)
field_size_bits = field_size_bytes * 8
if field_size_bits in [8, 16, 32, 64]:
int_width = field_size_bits
logger.info(f"Determined field size: {int_width} bits")
# Special handling for struct_xdp_md i32 fields
# Load as i32 but extend to i64 before storing
if struct_name == "struct_xdp_md" and int_width == 32:
needs_zext = True
logger.info(
"struct_xdp_md i32 field detected, will zero-extend to i64"
)
else:
logger.warning(
f"Unusual field size {field_size_bits} bits, using default 64"
)
except Exception as e:
logger.warning(
f"Could not determine field size: {e}, using default 64"
)
elif field_data.type.__module__ == "vmlinux":
# For pointers to structs or complex vmlinux types
if field_data.ctype_complex_type is not None and issubclass(
field_data.ctype_complex_type, ctypes._Pointer
):
int_width = 64 # Pointers are always 64-bit
logger.info("Field is a pointer type, using 64 bits")
# TODO: Add handling for other complex types (arrays, embedded structs, etc.)
else:
logger.warning("Complex vmlinux field type, using default 64 bits")
# Bitcast to appropriate pointer type based on determined width
ptr_type = ir.PointerType(ir.IntType(int_width))
typed_ptr = builder.bitcast(verified_ptr, ptr_type)
# Load and return the value
value = builder.load(typed_ptr)
# Zero-extend i32 to i64 for struct_xdp_md fields
if needs_zext:
value = builder.zext(value, ir.IntType(64))
logger.info("Zero-extended i32 value to i64 for struct_xdp_md field")
return value
def has_field(self, struct_name, field_name):
"""Check if a vmlinux struct has a specific field"""
if self.is_vmlinux_struct(struct_name):
python_type = self.vmlinux_symtab[struct_name].python_type
return hasattr(python_type, field_name)
return False
def get_field_type(self, vmlinux_struct_name, field_name):
"""Get the type of a field in a vmlinux struct"""
if self.is_vmlinux_struct(vmlinux_struct_name):
python_type = self.vmlinux_symtab[vmlinux_struct_name].python_type
if hasattr(python_type, field_name):
return self.vmlinux_symtab[vmlinux_struct_name].members[field_name]
else:
raise ValueError(
f"Field {field_name} not found in vmlinux struct {vmlinux_struct_name}"
)
else:
raise ValueError(f"{vmlinux_struct_name} is not a vmlinux struct")
def get_field_index(self, vmlinux_struct_name, field_name):
"""Get the type of a field in a vmlinux struct"""
if self.is_vmlinux_struct(vmlinux_struct_name):
python_type = self.vmlinux_symtab[vmlinux_struct_name].python_type
if hasattr(python_type, field_name):
return list(
self.vmlinux_symtab[vmlinux_struct_name].members.keys()
).index(field_name)
else:
raise ValueError(
f"Field {field_name} not found in vmlinux struct {vmlinux_struct_name}"
)
else:
raise ValueError(f"{vmlinux_struct_name} is not a vmlinux struct")

View File

@ -1,19 +1,22 @@
BPF_CLANG := clang
CFLAGS := -O2 -emit-llvm -target bpf -c
CFLAGS := -emit-llvm -target bpf -c
SRC := $(wildcard *.bpf.c)
LL := $(SRC:.bpf.c=.bpf.ll)
OBJ := $(SRC:.bpf.c=.bpf.o)
LL0 := $(SRC:.bpf.c=.bpf.o0.ll)
.PHONY: all clean
all: $(LL) $(OBJ)
all: $(LL) $(OBJ) $(LL0)
%.bpf.o: %.bpf.c
$(BPF_CLANG) -O2 -g -target bpf -c $< -o $@
%.bpf.ll: %.bpf.c
$(BPF_CLANG) $(CFLAGS) -g -S $< -o $@
$(BPF_CLANG) $(CFLAGS) -O2 -g -S $< -o $@
%.bpf.o0.ll: %.bpf.c
$(BPF_CLANG) $(CFLAGS) -O0 -g -S $< -o $@
clean:
rm -f $(LL) $(OBJ)
rm -f $(LL) $(OBJ) $(LL0)

View File

@ -1,25 +0,0 @@
#define __TARGET_ARCH_arm64
#include "vmlinux.h"
#include <bpf/bpf_helpers.h>
#include <bpf/bpf_tracing.h>
#include <bpf/bpf_core_read.h>
// Map: key = struct request*, value = u64 timestamp
struct {
__uint(type, BPF_MAP_TYPE_HASH);
__type(key, struct request *);
__type(value, u64);
__uint(max_entries, 1024);
} start SEC(".maps");
// Attach to kprobe for blk_start_request
SEC("kprobe/blk_start_request")
int BPF_KPROBE(trace_start, struct request *req)
{
u64 ts = bpf_ktime_get_ns();
bpf_map_update_elem(&start, &req, &ts, BPF_ANY);
return 0;
}
char LICENSE[] SEC("license") = "GPL";

View File

@ -0,0 +1,15 @@
#include <linux/bpf.h>
#include <bpf/bpf_helpers.h>
SEC("xdp")
int print_xdp_data(struct xdp_md *ctx)
{
// 'data' is a pointer to the start of packet data
long data = (long)ctx->data;
bpf_printk("ctx->data = %lld\n", data);
return XDP_PASS;
}
char LICENSE[] SEC("license") = "GPL";

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@ -2,18 +2,75 @@
#include <bpf/bpf_helpers.h>
#include <bpf/bpf_tracing.h>
char LICENSE[] SEC("license") = "Dual BSD/GPL";
char LICENSE[] SEC("license") = "GPL";
SEC("kprobe/do_unlinkat")
int kprobe_execve(struct pt_regs *ctx)
{
bpf_printk("unlinkat created");
return 0;
}
SEC("kretprobe/do_unlinkat")
int kretprobe_execve(struct pt_regs *ctx)
{
bpf_printk("unlinkat returned\n");
unsigned long r15 = ctx->r15;
bpf_printk("r15: %lld", r15);
unsigned long r14 = ctx->r14;
bpf_printk("r14: %lld", r14);
unsigned long r13 = ctx->r13;
bpf_printk("r13: %lld", r13);
unsigned long r12 = ctx->r12;
bpf_printk("r12: %lld", r12);
unsigned long bp = ctx->bp;
bpf_printk("rbp: %lld", bp);
unsigned long bx = ctx->bx;
bpf_printk("rbx: %lld", bx);
unsigned long r11 = ctx->r11;
bpf_printk("r11: %lld", r11);
unsigned long r10 = ctx->r10;
bpf_printk("r10: %lld", r10);
unsigned long r9 = ctx->r9;
bpf_printk("r9: %lld", r9);
unsigned long r8 = ctx->r8;
bpf_printk("r8: %lld", r8);
unsigned long ax = ctx->ax;
bpf_printk("rax: %lld", ax);
unsigned long cx = ctx->cx;
bpf_printk("rcx: %lld", cx);
unsigned long dx = ctx->dx;
bpf_printk("rdx: %lld", dx);
unsigned long si = ctx->si;
bpf_printk("rsi: %lld", si);
unsigned long di = ctx->di;
bpf_printk("rdi: %lld", di);
unsigned long orig_ax = ctx->orig_ax;
bpf_printk("orig_rax: %lld", orig_ax);
unsigned long ip = ctx->ip;
bpf_printk("rip: %lld", ip);
unsigned long cs = ctx->cs;
bpf_printk("cs: %lld", cs);
unsigned long flags = ctx->flags;
bpf_printk("eflags: %lld", flags);
unsigned long sp = ctx->sp;
bpf_printk("rsp: %lld", sp);
unsigned long ss = ctx->ss;
bpf_printk("ss: %lld", ss);
return 0;
}

View File

@ -0,0 +1,18 @@
#include "vmlinux.h"
#include <bpf/bpf_helpers.h>
#include <bpf/bpf_tracing.h>
#include <bpf/bpf_core_read.h>
char LICENSE[] SEC("license") = "GPL";
SEC("kprobe/blk_mq_start_request")
int example(struct pt_regs *ctx)
{
u64 a = ctx->r15;
struct request *req = (struct request *)(ctx->di);
unsigned int something_ns = BPF_CORE_READ(req, timeout);
unsigned int data_len = BPF_CORE_READ(req, __data_len);
bpf_printk("data length %lld %ld %ld\n", data_len, something_ns, a);
return 0;
}

View File

@ -0,0 +1,18 @@
#include "vmlinux.h"
#include <bpf/bpf_helpers.h>
#include <bpf/bpf_tracing.h>
#include <bpf/bpf_core_read.h>
char LICENSE[] SEC("license") = "GPL";
SEC("kprobe/blk_mq_start_request")
int example(struct pt_regs *ctx)
{
u64 a = ctx->r15;
struct request *req = (struct request *)(ctx->di);
unsigned int something_ns = req->timeout;
unsigned int data_len = req->__data_len;
bpf_printk("data length %lld %ld %ld\n", data_len, something_ns, a);
return 0;
}

View File

@ -0,0 +1,42 @@
// SPDX-License-Identifier: GPL-2.0
#include "vmlinux.h"
#include <bpf/bpf_helpers.h>
#include <bpf/bpf_tracing.h>
/*
Information gained from reversing this (multiple kernel versions):
There is no point of
```llvm
tail call void @llvm.dbg.value(metadata ptr %0, metadata !60, metadata !DIExpression()), !dbg !70
```
and the first argument of passthrough is fucking useless. It just needs to be a distinct integer:
```llvm
%9 = tail call ptr @llvm.bpf.passthrough.p0.p0(i32 3, ptr %8)
```
*/
SEC("tp/syscalls/sys_enter_execve")
int handle_setuid_entry(struct trace_event_raw_sys_enter *ctx) {
// Access each argument separately with clear variable assignments
long int id = ctx->id;
bpf_printk("This is context field %d", id);
/*
* the IR to aim for is
* %2 = alloca ptr, align 8
* store ptr %0, ptr %2, align 8
* Above, %0 is the arg pointer
* %5 = load ptr, ptr %2, align 8
* %6 = getelementptr inbounds %struct.trace_event_raw_sys_enter, ptr %5, i32 0, i32 2
* %7 = load i64, ptr @"llvm.trace_event_raw_sys_enter:0:16$0:2:0", align 8
* %8 = bitcast ptr %5 to ptr
* %9 = getelementptr i8, ptr %8, i64 %7
* %10 = bitcast ptr %9 to ptr
* %11 = call ptr @llvm.bpf.passthrough.p0.p0(i32 0, ptr %10)
* %12 = load i64, ptr %11, align 8, !dbg !101
*
*/
return 0;
}
char LICENSE[] SEC("license") = "GPL";

121617
tests/c-form/vmlinux.h vendored

File diff suppressed because it is too large Load Diff

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@ -0,0 +1,21 @@
// xdp_rewrite.c
#include <linux/bpf.h>
#include <bpf/bpf_helpers.h>
#include <linux/if_ether.h>
SEC("xdp")
int xdp_rewrite_mac(struct xdp_md *ctx)
{
void *data_end = (void *)(long)ctx->data_end;
void *data = (void *)(long)ctx->data;
struct ethhdr *eth = data;
if ((void*)(eth + 1) > data_end)
return XDP_PASS;
__u8 new_src[ETH_ALEN] = {0x02,0x00,0x00,0x00,0x00,0x02};
for (int i = 0; i < ETH_ALEN; i++) eth->h_source[i] = new_src[i];
return XDP_PASS;
}
char _license[] SEC("license") = "GPL";

View File

@ -0,0 +1,30 @@
import logging
from pythonbpf import bpf, section, bpfglobal, compile_to_ir
from pythonbpf import compile # noqa: F401
from vmlinux import TASK_COMM_LEN # noqa: F401
from vmlinux import struct_trace_event_raw_sys_enter # noqa: F401
from ctypes import c_int64, c_int32, c_void_p # noqa: F401
# from vmlinux import struct_uinput_device
# from vmlinux import struct_blk_integrity_iter
@bpf
@section("tracepoint/syscalls/sys_enter_execve")
def hello_world(ctx: struct_trace_event_raw_sys_enter) -> c_int64:
b = ctx.args
c = b[0]
print(f"This is context args field {c}")
return c_int64(0)
@bpf
@bpfglobal
def LICENSE() -> str:
return "GPL"
compile_to_ir("args_test.py", "args_test.ll", loglevel=logging.INFO)
compile()

View File

@ -0,0 +1,22 @@
from vmlinux import XDP_PASS
from pythonbpf import bpf, section, bpfglobal, compile_to_ir
import logging
from ctypes import c_int64, c_void_p
@bpf
@section("kprobe/blk_mq_start_request")
def example(ctx: c_void_p) -> c_int64:
d = XDP_PASS # This gives an error, but
e = XDP_PASS + 0 # this does not
print(f"test1 {e} test2 {d}")
return c_int64(0)
@bpf
@bpfglobal
def LICENSE() -> str:
return "GPL"
compile_to_ir("assignment_handling.py", "assignment_handling.ll", loglevel=logging.INFO)

View File

@ -1,4 +1,4 @@
from pythonbpf import bpf, map, section, bpfglobal, compile, struct
from pythonbpf import bpf, map, section, bpfglobal, compile, struct, compile_to_ir
from ctypes import c_void_p, c_int64, c_int32, c_uint64
from pythonbpf.maps import HashMap
from pythonbpf.helper import ktime
@ -71,4 +71,5 @@ def LICENSE() -> str:
return "GPL"
compile_to_ir("comprehensive.py", "comprehensive.ll")
compile()

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@ -0,0 +1,42 @@
from pythonbpf import bpf, section, struct, bpfglobal, compile, map
from pythonbpf.maps import HashMap
from pythonbpf.helper import pid
from ctypes import c_void_p, c_int64
@bpf
@struct
class val_type:
counter: c_int64
shizzle: c_int64
@bpf
@map
def last() -> HashMap:
return HashMap(key=val_type, value=c_int64, max_entries=16)
@bpf
@section("tracepoint/syscalls/sys_enter_clone")
def hello_world(ctx: c_void_p) -> c_int64:
obj = val_type()
obj.counter, obj.shizzle = 42, 96
t = last.lookup(obj)
if t:
print(f"Found existing entry: counter={obj.counter}, pid={t}")
last.delete(obj)
return 0 # type: ignore [return-value]
val = pid()
last.update(obj, val)
print(f"Map updated!, {obj.counter}, {obj.shizzle}, {val}")
return 0 # type: ignore [return-value]
@bpf
@bpfglobal
def LICENSE() -> str:
return "GPL"
compile()

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@ -0,0 +1,31 @@
from ctypes import c_int64, c_void_p
from pythonbpf import bpf, section, bpfglobal, compile_to_ir, compile
from vmlinux import struct_xdp_md
from vmlinux import XDP_PASS
@bpf
@section("xdp")
def print_xdp_dat2a(ct2x: struct_xdp_md) -> c_int64:
data = ct2x.data # 32-bit field: packet start pointer
print(f"ct2x->data = {data}")
return c_int64(XDP_PASS)
@bpf
@section("xdp")
def print_xdp_data(ctx: struct_xdp_md) -> c_int64:
data = ctx.data # 32-bit field: packet start pointer
something = c_void_p(data)
print(f"ctx->data = {something}")
return c_int64(XDP_PASS)
@bpf
@bpfglobal
def LICENSE() -> str:
return "GPL"
compile_to_ir("i32_test.py", "i32_test.ll")
compile()

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@ -0,0 +1,24 @@
from ctypes import c_int64
from pythonbpf import bpf, section, bpfglobal, compile
from vmlinux import struct_xdp_md
from vmlinux import XDP_PASS
import logging
@bpf
@section("xdp")
def print_xdp_data(ctx: struct_xdp_md) -> c_int64:
data = 0
data = ctx.data # 32-bit field: packet start pointer
something = 2 + data
print(f"ctx->data = {something}")
return c_int64(XDP_PASS)
@bpf
@bpfglobal
def LICENSE() -> str:
return "GPL"
compile(logging.INFO)

View File

@ -0,0 +1,24 @@
from ctypes import c_int64
from pythonbpf import bpf, section, bpfglobal, compile, compile_to_ir
from vmlinux import struct_xdp_md
from vmlinux import XDP_PASS
import logging
@bpf
@section("xdp")
def print_xdp_data(ctx: struct_xdp_md) -> c_int64:
data = c_int64(ctx.data) # 32-bit field: packet start pointer
something = 2 + data
print(f"ctx->data = {something}")
return c_int64(XDP_PASS)
@bpf
@bpfglobal
def LICENSE() -> str:
return "GPL"
compile_to_ir("i32_test_fail_2.py", "i32_test_fail_2.ll")
compile(logging.INFO)

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@ -0,0 +1,53 @@
from pythonbpf import bpf, section, bpfglobal, BPF, trace_pipe
from pythonbpf import compile # noqa: F401
from vmlinux import struct_pt_regs
from ctypes import c_int64, c_int32, c_void_p # noqa: F401
@bpf
@section("kprobe/do_unlinkat")
def kprobe_execve(ctx: struct_pt_regs) -> c_int64:
r15 = ctx.r15
r14 = ctx.r14
r13 = ctx.r13
r12 = ctx.r12
bp = ctx.bp
bx = ctx.bx
r11 = ctx.r11
r10 = ctx.r10
r9 = ctx.r9
r8 = ctx.r8
ax = ctx.ax
cx = ctx.cx
dx = ctx.dx
si = ctx.si
di = ctx.di
orig_ax = ctx.orig_ax
ip = ctx.ip
cs = ctx.cs
flags = ctx.flags
sp = ctx.sp
ss = ctx.ss
print(f"r15={r15} r14={r14} r13={r13}")
print(f"r12={r12} rbp={bp} rbx={bx}")
print(f"r11={r11} r10={r10} r9={r9}")
print(f"r8={r8} rax={ax} rcx={cx}")
print(f"rdx={dx} rsi={si} rdi={di}")
print(f"orig_rax={orig_ax} rip={ip} cs={cs}")
print(f"eflags={flags} rsp={sp} ss={ss}")
return c_int64(0)
@bpf
@bpfglobal
def LICENSE() -> str:
return "GPL"
b = BPF()
b.load()
b.attach_all()
trace_pipe()

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@ -0,0 +1,27 @@
from vmlinux import struct_request, struct_pt_regs
from pythonbpf import bpf, section, bpfglobal, compile_to_ir, compile
import logging
from ctypes import c_int64
@bpf
@section("kprobe/blk_mq_start_request")
def example(ctx: struct_pt_regs) -> c_int64:
a = ctx.r15
req = struct_request(ctx.di)
d = req.__data_len
b = ctx.r12
c = req.timeout
print(f"data length {d} and {c} and {a}")
print(f"ctx arg {b}")
return c_int64(0)
@bpf
@bpfglobal
def LICENSE() -> str:
return "GPL"
compile_to_ir("requests.py", "requests.ll", loglevel=logging.INFO)
compile()

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@ -0,0 +1,21 @@
from vmlinux import struct_pt_regs
from pythonbpf import bpf, section, bpfglobal, compile_to_ir
import logging
from ctypes import c_int64
@bpf
@section("kprobe/blk_mq_start_request")
def example(ctx: struct_pt_regs) -> c_int64:
req = ctx.di
print(f"data length {req}")
return c_int64(0)
@bpf
@bpfglobal
def LICENSE() -> str:
return "GPL"
compile_to_ir("requests2.py", "requests2.ll", loglevel=logging.INFO)

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@ -44,4 +44,4 @@ def LICENSE() -> str:
compile_to_ir("simple_struct_test.py", "simple_struct_test.ll", loglevel=logging.DEBUG)
# compile()
compile()

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import logging
from pythonbpf import bpf, section, bpfglobal, compile_to_ir
from pythonbpf import compile # noqa: F401
from vmlinux import TASK_COMM_LEN # noqa: F401
from vmlinux import struct_trace_event_raw_sys_enter # noqa: F401
from ctypes import c_int64, c_int32, c_void_p # noqa: F401
# from vmlinux import struct_uinput_device
# from vmlinux import struct_blk_integrity_iter
@bpf
@section("tracepoint/syscalls/sys_enter_execve")
def hello_world(ctx: struct_trace_event_raw_sys_enter) -> c_int64:
b = ctx.id
print(f"This is context field {b}")
return c_int64(0)
@bpf
@bpfglobal
def LICENSE() -> str:
return "GPL"
compile_to_ir("struct_field_access.py", "struct_field_access.ll", loglevel=logging.INFO)
compile()