24 Commits

Author SHA1 Message Date
7ae629e8f7 bump version to v0.1.5 2025-10-16 19:04:04 +05:30
dd734ea2aa Merge pull request #56 from pythonbpf/vmlinux-ir-gen
Adds IR and debug info generation capabilities for vmlinux imported structs
2025-10-16 18:59:32 +05:30
71d005b6b1 complete vmlinux struct name generation in IR.
* Breaks when it finds unions.
* Still does not support function pointers.
2025-10-16 18:58:28 +05:30
5d9a29ee8e format chore 2025-10-16 18:22:25 +05:30
041e538b53 fix errors. Does not support union name resolution yet. 2025-10-16 18:21:14 +05:30
5413cc793b something fixed itself. 2025-10-16 18:06:36 +05:30
f21837aefe support most bitfields 2025-10-16 04:13:04 +05:30
0f5c1fa752 format chore 2025-10-16 04:10:24 +05:30
de02731ea1 add support with ctypes getattr offset. Also supports bitfields.
* breaks when struct_ring_buffer_per_cpu
2025-10-16 04:08:06 +05:30
c22d85ceb8 add array field generation support 2025-10-15 23:56:04 +05:30
2b3c81affa TODO added for llvmlite attribute issue
*Refer: https://github.com/numba/llvmlite/issues/1331

Signed-off-by: varun-r-mallya <varunrmallya@gmail.com>
2025-10-15 21:35:28 +05:30
8372111616 add basic IR gen strategy 2025-10-15 21:25:53 +05:30
eb4ee64ee5 Revert "float vmlinux_assignments_symtab"
This reverts commit ce7b170fea.
2025-10-15 19:11:53 +05:30
ce7b170fea float vmlinux_assignments_symtab 2025-10-15 18:19:51 +05:30
9a60dd87e3 Merge pull request #55 from pythonbpf/vmlinux-ir-gen
remove bitfield support and add assignment support
2025-10-15 18:07:27 +05:30
c499fe7421 solve static typing issues 2025-10-15 18:05:57 +05:30
8239097fbb format chore 2025-10-15 17:49:38 +05:30
a4cfc2b7aa add assignments table and offset handler 2025-10-15 17:49:20 +05:30
69b73003ca setup skeleton for offset calculation 2025-10-15 04:42:38 +05:30
11e8e72188 add base for ir gen 2025-10-15 02:00:23 +05:30
d3f0e3b2ef remove tbaa_gen and make IR generator module 2025-10-14 03:09:18 +05:30
09ba749b46 Merge pull request #52 from pythonbpf/vmlinux-ir-gen
Dependency tree functionality to semantic analyser
2025-10-14 02:37:43 +05:30
a03d3e5d4c format chore 2025-10-14 02:36:04 +05:30
e1f9ac6ba0 add dependency tree functionality 2025-10-14 02:35:49 +05:30
32 changed files with 545 additions and 1188 deletions

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@ -1,34 +0,0 @@
from pythonbpf import bpf, section, bpfglobal, BPF, trace_fields
from ctypes import c_void_p, c_int64
@bpf
@section("tracepoint/syscalls/sys_enter_clone")
def hello_world(ctx: c_void_p) -> c_int64:
print("Hello, World!")
return 0 # type: ignore [return-value]
@bpf
@bpfglobal
def LICENSE() -> str:
return "GPL"
# Compile and load
b = BPF()
b.load()
b.attach_all()
# header
print(f"{'TIME(s)':<18} {'COMM':<16} {'PID':<6} {'MESSAGE'}")
# format output
while True:
try:
(task, pid, cpu, flags, ts, msg) = trace_fields()
except ValueError:
continue
except KeyboardInterrupt:
exit()
print(f"{ts:<18} {task:<16} {pid:<6} {msg}")

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@ -1,61 +0,0 @@
from pythonbpf import bpf, map, struct, section, bpfglobal, BPF
from pythonbpf.helper import ktime, pid, comm
from pythonbpf.maps import PerfEventArray
from ctypes import c_void_p, c_int64, c_uint64
@bpf
@struct
class data_t:
pid: c_uint64
ts: c_uint64
comm: str(16) # type: ignore [valid-type]
@bpf
@map
def events() -> PerfEventArray:
return PerfEventArray(key_size=c_int64, value_size=c_int64)
@bpf
@section("tracepoint/syscalls/sys_enter_clone")
def hello(ctx: c_void_p) -> c_int64:
dataobj = data_t()
dataobj.pid, dataobj.ts = pid(), ktime()
comm(dataobj.comm)
events.output(dataobj)
return 0 # type: ignore [return-value]
@bpf
@bpfglobal
def LICENSE() -> str:
return "GPL"
# Compile and load
b = BPF()
b.load()
b.attach_all()
start = 0
def callback(cpu, event):
global start
if start == 0:
start = event.ts
ts = (event.ts - start) / 1e9
print(f"[CPU {cpu}] PID: {event.pid}, TS: {ts}, COMM: {event.comm.decode()}")
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)
except KeyboardInterrupt:
print("Stopping...")

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@ -1,23 +0,0 @@
from pythonbpf import bpf, section, bpfglobal, BPF, trace_pipe
from ctypes import c_void_p, c_int64
@bpf
@section("tracepoint/syscalls/sys_enter_clone")
def hello_world(ctx: c_void_p) -> c_int64:
print("Hello, World!")
return 0 # type: ignore [return-value]
@bpf
@bpfglobal
def LICENSE() -> str:
return "GPL"
# Compile and load
b = BPF()
b.load()
b.attach_all()
trace_pipe()

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@ -1,58 +0,0 @@
from pythonbpf import bpf, map, section, bpfglobal, BPF, trace_fields
from pythonbpf.helper import ktime
from pythonbpf.maps import HashMap
from ctypes import c_void_p, c_int64
@bpf
@map
def last() -> HashMap:
return HashMap(key=c_int64, value=c_int64, max_entries=2)
@bpf
@section("tracepoint/syscalls/sys_enter_sync")
def do_trace(ctx: c_void_p) -> c_int64:
ts_key, cnt_key = 0, 1
tsp, cntp = last.lookup(ts_key), last.lookup(cnt_key)
if not cntp:
last.update(cnt_key, 0)
cntp = last.lookup(cnt_key)
if tsp:
delta = ktime() - tsp
if delta < 1000000000:
time_ms = delta // 1000000
print(f"{time_ms} {cntp}")
last.delete(ts_key)
else:
last.update(ts_key, ktime())
last.update(cnt_key, cntp + 1)
return 0 # type: ignore [return-value]
@bpf
@bpfglobal
def LICENSE() -> str:
return "GPL"
# Compile and load
b = BPF()
b.load()
b.attach_all()
print("Tracing for quick sync's... Ctrl-C to end")
# format output
start = 0
while True:
try:
task, pid, cpu, flags, ts, msg = trace_fields()
if start == 0:
start = ts
ts -= start
ms, cnt = msg.split()
print(f"At time {ts} s: Multiple syncs detected, last {ms} ms ago. Count {cnt}")
except KeyboardInterrupt:
exit()

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@ -1,78 +0,0 @@
from pythonbpf import bpf, map, struct, section, bpfglobal, BPF
from pythonbpf.helper import ktime
from pythonbpf.maps import HashMap
from pythonbpf.maps import PerfEventArray
from ctypes import c_void_p, c_int64
@bpf
@struct
class data_t:
ts: c_int64
ms: c_int64
@bpf
@map
def events() -> PerfEventArray:
return PerfEventArray(key_size=c_int64, value_size=c_int64)
@bpf
@map
def last() -> HashMap:
return HashMap(key=c_int64, value=c_int64, max_entries=1)
@bpf
@section("tracepoint/syscalls/sys_enter_sync")
def do_trace(ctx: c_void_p) -> c_int64:
dat, dat.ts, key = data_t(), ktime(), 0
tsp = last.lookup(key)
if tsp:
delta = ktime() - tsp
if delta < 1000000000:
dat.ms = delta // 1000000
events.output(dat)
last.delete(key)
else:
last.update(key, ktime())
return 0 # type: ignore [return-value]
@bpf
@bpfglobal
def LICENSE() -> str:
return "GPL"
# Compile and load
b = BPF()
b.load()
b.attach_all()
print("Tracing for quick sync's... Ctrl-C to end")
# format output
start = 0
def callback(cpu, event):
global start
if start == 0:
start = event.ts
event.ts -= start
print(
f"At time {event.ts / 1e9} s: Multiple sync detected, Last sync: {event.ms} ms ago"
)
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)
except KeyboardInterrupt:
print("Stopping...")

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@ -1,53 +0,0 @@
from pythonbpf import bpf, map, section, bpfglobal, BPF, trace_fields
from pythonbpf.helper import ktime
from pythonbpf.maps import HashMap
from ctypes import c_void_p, c_int64
@bpf
@map
def last() -> HashMap:
return HashMap(key=c_int64, value=c_int64, max_entries=1)
@bpf
@section("tracepoint/syscalls/sys_enter_sync")
def do_trace(ctx: c_void_p) -> c_int64:
key = 0
tsp = last.lookup(key)
if tsp:
delta = ktime() - tsp
if delta < 1000000000:
time_ms = delta // 1000000
print(f"{time_ms}")
last.delete(key)
else:
last.update(key, ktime())
return 0 # type: ignore [return-value]
@bpf
@bpfglobal
def LICENSE() -> str:
return "GPL"
# Compile and load
b = BPF()
b.load()
b.attach_all()
print("Tracing for quick sync's... Ctrl-C to end")
# format output
start = 0
while True:
try:
task, pid, cpu, flags, ts, ms = trace_fields()
if start == 0:
start = ts
ts -= start
print(f"At time {ts} s: Multiple syncs detected, last {ms} ms ago")
except KeyboardInterrupt:
exit()

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@ -1,23 +0,0 @@
from pythonbpf import bpf, section, bpfglobal, BPF, trace_pipe
from ctypes import c_void_p, c_int64
@bpf
@section("tracepoint/syscalls/sys_enter_sync")
def hello_world(ctx: c_void_p) -> c_int64:
print("sys_sync() called")
return c_int64(0)
@bpf
@bpfglobal
def LICENSE() -> str:
return "GPL"
# Compile and load
b = BPF()
b.load()
b.attach_all()
print("Tracing sys_sync()... Ctrl-C to end.")
trace_pipe()

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@ -4,7 +4,7 @@ build-backend = "setuptools.build_meta"
[project]
name = "pythonbpf"
version = "0.1.4"
version = "0.1.5"
description = "Reduced Python frontend for eBPF"
authors = [
{ name = "r41k0u", email="pragyanshchaturvedi18@gmail.com" },

View File

@ -1,6 +1,5 @@
from .decorators import bpf, map, section, bpfglobal, struct
from .codegen import compile_to_ir, compile, BPF
from .utils import trace_pipe, trace_fields
__all__ = [
"bpf",
@ -11,6 +10,4 @@ __all__ = [
"compile_to_ir",
"compile",
"BPF",
"trace_pipe",
"trace_fields",
]

View File

@ -22,68 +22,44 @@ class LocalSymbol:
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):
if not isinstance(stmt.value, ast.Tuple):
logger.warning("Mismatched multi-target assignment, skipping allocation")
return
targets, rvals = stmt.targets[0].elts, stmt.value.elts
if len(targets) != len(rvals):
logger.warning("length of LHS != length of RHS, skipping allocation")
return
return targets, rvals
return stmt.targets, [stmt.value]
def handle_assign_allocation(builder, stmt, local_sym_tab, structs_sym_tab):
"""Handle memory allocation for assignment statements."""
logger.info(f"Handling assignment for allocation: {ast.dump(stmt)}")
# Validate assignment
if len(stmt.targets) != 1:
logger.warning("Multi-target assignment not supported, skipping allocation")
return
# NOTE: Support multi-target assignments (e.g.: a, b = 1, 2)
targets, rvals = create_targets_and_rvals(stmt)
target = stmt.targets[0]
for target, rval in zip(targets, rvals):
# Skip non-name targets (e.g., struct field assignments)
if isinstance(target, ast.Attribute):
logger.debug(
f"Struct field assignment to {target.attr}, no allocation needed"
)
continue
# Skip non-name targets (e.g., struct field assignments)
if isinstance(target, ast.Attribute):
logger.debug(f"Struct field assignment to {target.attr}, no allocation needed")
return
if not isinstance(target, ast.Name):
logger.warning(
f"Unsupported assignment target type: {type(target).__name__}"
)
continue
if not isinstance(target, ast.Name):
logger.warning(f"Unsupported assignment target type: {type(target).__name__}")
return
var_name = target.id
var_name = target.id
rval = stmt.value
# Skip if already allocated
if var_name in local_sym_tab:
logger.debug(f"Variable {var_name} already allocated, skipping")
continue
# Skip if already allocated
if var_name in local_sym_tab:
logger.debug(f"Variable {var_name} already allocated, skipping")
return
# 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)
elif isinstance(rval, ast.Constant):
_allocate_for_constant(builder, var_name, rval, local_sym_tab)
elif isinstance(rval, ast.BinOp):
_allocate_for_binop(builder, var_name, local_sym_tab)
elif isinstance(rval, ast.Name):
# Variable-to-variable assignment (b = a)
_allocate_for_name(builder, var_name, rval, local_sym_tab)
elif isinstance(rval, ast.Attribute):
# Struct field-to-variable assignment (a = dat.fld)
_allocate_for_attribute(
builder, var_name, rval, local_sym_tab, structs_sym_tab
)
else:
logger.warning(
f"Unsupported assignment value type for {var_name}: {type(rval).__name__}"
)
# 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)
elif isinstance(rval, ast.Constant):
_allocate_for_constant(builder, var_name, rval, local_sym_tab)
elif isinstance(rval, ast.BinOp):
_allocate_for_binop(builder, var_name, local_sym_tab)
else:
logger.warning(
f"Unsupported assignment value type for {var_name}: {type(rval).__name__}"
)
def _allocate_for_call(builder, var_name, rval, local_sym_tab, structs_sym_tab):
@ -200,88 +176,3 @@ def allocate_temp_pool(builder, max_temps, local_sym_tab):
temp_var = builder.alloca(ir.IntType(64), name=temp_name)
temp_var.align = 8
local_sym_tab[temp_name] = LocalSymbol(temp_var, ir.IntType(64))
def _allocate_for_name(builder, var_name, rval, local_sym_tab):
"""Allocate memory for variable-to-variable assignment (b = a)."""
source_var = rval.id
if source_var not in local_sym_tab:
logger.error(f"Source variable '{source_var}' not found in symbol table")
return
# Get type and metadata from source variable
source_symbol = local_sym_tab[source_var]
# Allocate with same type and alignment
var = _allocate_with_type(builder, var_name, source_symbol.ir_type)
local_sym_tab[var_name] = LocalSymbol(
var, source_symbol.ir_type, source_symbol.metadata
)
logger.info(
f"Pre-allocated {var_name} from {source_var} with type {source_symbol.ir_type}"
)
def _allocate_for_attribute(builder, var_name, rval, local_sym_tab, structs_sym_tab):
"""Allocate memory for struct field-to-variable assignment (a = dat.fld)."""
if not isinstance(rval.value, ast.Name):
logger.warning(f"Complex attribute access not supported for {var_name}")
return
struct_var = rval.value.id
field_name = rval.attr
# Validate struct and field
if struct_var not in local_sym_tab:
logger.error(f"Struct variable '{struct_var}' not found")
return
struct_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")
return
struct_info = structs_sym_tab[struct_type]
if field_name not in struct_info.fields:
logger.error(f"Field '{field_name}' not found in struct '{struct_type}'")
return
# Get field type
field_type = struct_info.field_type(field_name)
# Special case: char array -> allocate as i8* pointer instead
if (
isinstance(field_type, ir.ArrayType)
and isinstance(field_type.element, ir.IntType)
and field_type.element.width == 8
):
alloc_type = ir.PointerType(ir.IntType(8))
logger.info(f"Allocating {var_name} as i8* (pointer to char array)")
else:
alloc_type = field_type
var = _allocate_with_type(builder, var_name, alloc_type)
local_sym_tab[var_name] = LocalSymbol(var, alloc_type)
logger.info(
f"Pre-allocated {var_name} from {struct_var}.{field_name} with type {alloc_type}"
)
def _allocate_with_type(builder, var_name, ir_type):
"""Allocate variable with appropriate alignment for type."""
var = builder.alloca(ir_type, name=var_name)
var.align = _get_alignment(ir_type)
return var
def _get_alignment(ir_type):
"""Get appropriate alignment for IR type."""
if isinstance(ir_type, ir.IntType):
return ir_type.width // 8
elif isinstance(ir_type, ir.ArrayType) and isinstance(ir_type.element, ir.IntType):
return ir_type.element.width // 8
else:
return 8 # Default: pointer size

View File

@ -2,7 +2,6 @@ import ast
import logging
from llvmlite import ir
from pythonbpf.expr import eval_expr
from pythonbpf.helper import emit_probe_read_kernel_str_call
logger = logging.getLogger(__name__)
@ -28,82 +27,27 @@ def handle_struct_field_assignment(
# Get field pointer and evaluate value
field_ptr = struct_info.gep(builder, local_sym_tab[var_name].var, field_name)
field_type = struct_info.field_type(field_name)
val_result = eval_expr(
val = eval_expr(
func, module, builder, rval, local_sym_tab, map_sym_tab, structs_sym_tab
)
if val_result is None:
if val is None:
logger.error(f"Failed to evaluate value for {var_name}.{field_name}")
return
val, val_type = val_result
# Special case: i8* string to [N x i8] char array
if _is_char_array(field_type) and _is_i8_ptr(val_type):
_copy_string_to_char_array(
func,
module,
builder,
val,
field_ptr,
field_type,
local_sym_tab,
map_sym_tab,
structs_sym_tab,
# TODO: Handle string assignment to char array (not a priority)
field_type = struct_info.field_type(field_name)
if isinstance(field_type, ir.ArrayType) and val[1] == ir.PointerType(ir.IntType(8)):
logger.warning(
f"String to char array assignment not implemented for {var_name}.{field_name}"
)
logger.info(f"Copied string to char array {var_name}.{field_name}")
return
# Regular assignment
builder.store(val, field_ptr)
# Store the value
builder.store(val[0], field_ptr)
logger.info(f"Assigned to struct field {var_name}.{field_name}")
def _copy_string_to_char_array(
func,
module,
builder,
src_ptr,
dst_ptr,
array_type,
local_sym_tab,
map_sym_tab,
struct_sym_tab,
):
"""Copy string (i8*) to char array ([N x i8]) using bpf_probe_read_kernel_str"""
array_size = array_type.count
# Get pointer to first element: [N x i8]* -> i8*
dst_i8_ptr = builder.gep(
dst_ptr,
[ir.Constant(ir.IntType(32), 0), ir.Constant(ir.IntType(32), 0)],
inbounds=True,
)
# Use the shared emitter function
emit_probe_read_kernel_str_call(builder, dst_i8_ptr, array_size, src_ptr)
def _is_char_array(ir_type):
"""Check if type is [N x i8]."""
return (
isinstance(ir_type, ir.ArrayType)
and isinstance(ir_type.element, ir.IntType)
and ir_type.element.width == 8
)
def _is_i8_ptr(ir_type):
"""Check if type is i8*."""
return (
isinstance(ir_type, ir.PointerType)
and isinstance(ir_type.pointee, ir.IntType)
and ir_type.pointee.width == 8
)
def handle_variable_assignment(
func, module, builder, var_name, rval, local_sym_tab, map_sym_tab, structs_sym_tab
):
@ -127,17 +71,6 @@ def handle_variable_assignment(
logger.info(f"Initialized struct {struct_name} for variable {var_name}")
return True
# Special case: struct field char array -> pointer
# Handle this before eval_expr to get the pointer, not the value
if isinstance(rval, ast.Attribute) and isinstance(rval.value, ast.Name):
converted_val = _try_convert_char_array_to_ptr(
rval, var_type, builder, local_sym_tab, structs_sym_tab
)
if converted_val is not None:
builder.store(converted_val, var_ptr)
logger.info(f"Assigned char array pointer to {var_name}")
return True
val_result = eval_expr(
func, module, builder, rval, local_sym_tab, map_sym_tab, structs_sym_tab
)
@ -173,52 +106,3 @@ def handle_variable_assignment(
builder.store(val, var_ptr)
logger.info(f"Assigned value to variable {var_name}")
return True
def _try_convert_char_array_to_ptr(
rval, var_type, builder, local_sym_tab, structs_sym_tab
):
"""Try to convert char array field to i8* pointer"""
# Only convert if target is i8*
if not (
isinstance(var_type, ir.PointerType)
and isinstance(var_type.pointee, ir.IntType)
and var_type.pointee.width == 8
):
return None
struct_var = rval.value.id
field_name = rval.attr
# Validate struct
if struct_var not in local_sym_tab:
return None
struct_type = local_sym_tab[struct_var].metadata
if not struct_type or struct_type not in structs_sym_tab:
return None
struct_info = structs_sym_tab[struct_type]
if field_name not in struct_info.fields:
return None
field_type = struct_info.field_type(field_name)
# Check if it's a char array
if not (
isinstance(field_type, ir.ArrayType)
and isinstance(field_type.element, ir.IntType)
and field_type.element.width == 8
):
return None
# Get pointer to struct field
struct_ptr = local_sym_tab[struct_var].var
field_ptr = struct_info.gep(builder, struct_ptr, field_name)
# GEP to first element: [N x i8]* -> i8*
return builder.gep(
field_ptr,
[ir.Constant(ir.IntType(32), 0), ir.Constant(ir.IntType(32), 0)],
inbounds=True,
)

View File

@ -15,14 +15,24 @@ import os
import subprocess
import inspect
from pathlib import Path
from pylibbpf import BpfObject
from pylibbpf import BpfProgram
import tempfile
from logging import Logger
import logging
import re
logger: Logger = logging.getLogger(__name__)
VERSION = "v0.1.4"
VERSION = "v0.1.5"
def finalize_module(original_str):
"""After all IR generation is complete, we monkey patch btf_ama attribute"""
# Create a string with applied transformation of btf_ama attribute addition to BTF struct field accesses.
pattern = r'(@"llvm\.[^"]+:[^"]*" = external global i64, !llvm\.preserve\.access\.index ![0-9]+)'
replacement = r'\1 "btf_ama"'
return re.sub(pattern, replacement, original_str)
def find_bpf_chunks(tree):
@ -55,7 +65,6 @@ def processor(source_code, filename, module):
func_proc(tree, module, bpf_chunks, map_sym_tab, structs_sym_tab)
globals_list_creation(tree, module)
return structs_sym_tab, map_sym_tab
def compile_to_ir(filename: str, output: str, loglevel=logging.INFO):
@ -81,7 +90,7 @@ def compile_to_ir(filename: str, output: str, loglevel=logging.INFO):
True,
)
structs_sym_tab, maps_sym_tab = processor(source, filename, module)
processor(source, filename, module)
wchar_size = module.add_metadata(
[
@ -122,13 +131,15 @@ 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))
logger.info(f"IR written to {output}")
with open(output, "w") as f:
f.write(f'source_filename = "{filename}"\n')
f.write(str(module))
f.write(module_string)
f.write("\n")
return output, structs_sym_tab, maps_sym_tab
return output
def _run_llc(ll_file, obj_file):
@ -158,7 +169,7 @@ def _run_llc(ll_file, obj_file):
return False
def compile(loglevel=logging.WARNING) -> bool:
def compile(loglevel=logging.INFO) -> bool:
# Look one level up the stack to the caller of this function
caller_frame = inspect.stack()[1]
caller_file = Path(caller_frame.filename).resolve()
@ -166,19 +177,18 @@ def compile(loglevel=logging.WARNING) -> bool:
ll_file = Path("/tmp") / caller_file.with_suffix(".ll").name
o_file = caller_file.with_suffix(".o")
_, structs_sym_tab, maps_sym_tab = compile_to_ir(
str(caller_file), str(ll_file), loglevel=loglevel
success = True
success = (
compile_to_ir(str(caller_file), str(ll_file), loglevel=loglevel) and success
)
if not _run_llc(ll_file, o_file):
logger.error("Compilation to object file failed.")
return False
success = _run_llc(ll_file, o_file) and success
logger.info(f"Object written to {o_file}")
return True
return success
def BPF(loglevel=logging.WARNING) -> BpfObject:
def BPF(loglevel=logging.INFO) -> BpfProgram:
caller_frame = inspect.stack()[1]
src = inspect.getsource(caller_frame.frame)
with tempfile.NamedTemporaryFile(
@ -191,9 +201,7 @@ def BPF(loglevel=logging.WARNING) -> BpfObject:
f.write(src)
f.flush()
source = f.name
_, structs_sym_tab, maps_sym_tab = compile_to_ir(
source, str(inter.name), loglevel=loglevel
)
compile_to_ir(source, str(inter.name), loglevel=loglevel)
_run_llc(str(inter.name), str(obj_file.name))
return BpfObject(str(obj_file.name), structs=structs_sym_tab)
return BpfProgram(str(obj_file.name))

View File

@ -12,11 +12,7 @@ from pythonbpf.assign_pass import (
handle_variable_assignment,
handle_struct_field_assignment,
)
from pythonbpf.allocation_pass import (
handle_assign_allocation,
allocate_temp_pool,
create_targets_and_rvals,
)
from pythonbpf.allocation_pass import handle_assign_allocation, allocate_temp_pool
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
@ -144,43 +140,48 @@ def handle_assign(
):
"""Handle assignment statements in the function body."""
# NOTE: Support multi-target assignments (e.g.: a, b = 1, 2)
targets, rvals = create_targets_and_rvals(stmt)
# TODO: Support this later
# GH #37
if len(stmt.targets) != 1:
logger.error("Multi-target assignment is not supported for now")
return
for target, rval in zip(targets, rvals):
if isinstance(target, ast.Name):
# NOTE: Simple variable assignment case: x = 5
var_name = target.id
result = handle_variable_assignment(
func,
module,
builder,
var_name,
rval,
local_sym_tab,
map_sym_tab,
structs_sym_tab,
)
if not result:
logger.error(f"Failed to handle assignment to {var_name}")
continue
target = stmt.targets[0]
rval = stmt.value
if isinstance(target, ast.Attribute):
# NOTE: Struct field assignment case: pkt.field = value
handle_struct_field_assignment(
func,
module,
builder,
target,
rval,
local_sym_tab,
map_sym_tab,
structs_sym_tab,
)
continue
if isinstance(target, ast.Name):
# NOTE: Simple variable assignment case: x = 5
var_name = target.id
result = handle_variable_assignment(
func,
module,
builder,
var_name,
rval,
local_sym_tab,
map_sym_tab,
structs_sym_tab,
)
if not result:
logger.error(f"Failed to handle assignment to {var_name}")
return
# Unsupported target type
logger.error(f"Unsupported assignment target: {ast.dump(target)}")
if isinstance(target, ast.Attribute):
# NOTE: Struct field assignment case: pkt.field = value
handle_struct_field_assignment(
func,
module,
builder,
target,
rval,
local_sym_tab,
map_sym_tab,
structs_sym_tab,
)
return
# Unsupported target type
logger.error(f"Unsupported assignment target: {ast.dump(target)}")
def handle_cond(

View File

@ -1,7 +1,7 @@
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 .helpers import ktime, pid, deref, comm, probe_read_str, XDP_DROP, XDP_PASS
from .bpf_helper_handler import handle_helper_call
from .helpers import ktime, pid, deref, XDP_DROP, XDP_PASS
# Register the helper handler with expr module
@ -59,12 +59,9 @@ __all__ = [
"HelperHandlerRegistry",
"reset_scratch_pool",
"handle_helper_call",
"emit_probe_read_kernel_str_call",
"ktime",
"pid",
"deref",
"comm",
"probe_read_str",
"XDP_DROP",
"XDP_PASS",
]

View File

@ -7,9 +7,6 @@ from .helper_utils import (
get_or_create_ptr_from_arg,
get_flags_val,
get_data_ptr_and_size,
get_buffer_ptr_and_size,
get_char_array_ptr_and_size,
get_ptr_from_arg,
)
from .printk_formatter import simple_string_print, handle_fstring_print
@ -26,9 +23,7 @@ class BPFHelperID(Enum):
BPF_KTIME_GET_NS = 5
BPF_PRINTK = 6
BPF_GET_CURRENT_PID_TGID = 14
BPF_GET_CURRENT_COMM = 16
BPF_PERF_EVENT_OUTPUT = 25
BPF_PROBE_READ_KERNEL_STR = 115
@HelperHandlerRegistry.register("ktime")
@ -239,63 +234,6 @@ def bpf_map_delete_elem_emitter(
return result, None
@HelperHandlerRegistry.register("comm")
def bpf_get_current_comm_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_current_comm helper function call.
Accepts: comm(dataobj.field) or comm(my_buffer)
"""
if not call.args or len(call.args) != 1:
raise ValueError(
f"comm expects exactly one argument (buffer), got {len(call.args)}"
)
buf_arg = call.args[0]
# Extract buffer pointer and size
buf_ptr, buf_size = get_buffer_ptr_and_size(
buf_arg, builder, local_sym_tab, struct_sym_tab
)
# Validate it's a char array
if not isinstance(
buf_ptr.type.pointee, ir.ArrayType
) or buf_ptr.type.pointee.element != ir.IntType(8):
raise ValueError(
f"comm expects a char array buffer, got {buf_ptr.type.pointee}"
)
# Cast to void* and call helper
buf_void_ptr = builder.bitcast(buf_ptr, ir.PointerType())
fn_type = ir.FunctionType(
ir.IntType(64),
[ir.PointerType(), ir.IntType(32)],
var_arg=False,
)
fn_ptr = builder.inttoptr(
ir.Constant(ir.IntType(64), BPFHelperID.BPF_GET_CURRENT_COMM.value),
ir.PointerType(fn_type),
)
result = builder.call(
fn_ptr, [buf_void_ptr, ir.Constant(ir.IntType(32), buf_size)], tail=False
)
logger.info(f"Emitted bpf_get_current_comm with {buf_size} byte buffer")
return result, None
@HelperHandlerRegistry.register("pid")
def bpf_get_current_pid_tgid_emitter(
call,
@ -371,68 +309,6 @@ def bpf_perf_event_output_handler(
return result, None
def emit_probe_read_kernel_str_call(builder, dst_ptr, dst_size, src_ptr):
"""Emit LLVM IR call to bpf_probe_read_kernel_str"""
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_STR.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_str (size={dst_size})")
return result
@HelperHandlerRegistry.register("probe_read_str")
def bpf_probe_read_kernel_str_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_str helper."""
if len(call.args) != 2:
raise ValueError(
f"probe_read_str expects 2 args (dst, src), got {len(call.args)}"
)
# Get destination buffer (char array -> i8*)
dst_ptr, dst_size = get_char_array_ptr_and_size(
call.args[0], builder, local_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_str_call(builder, dst_ptr, dst_size, src_ptr)
logger.info(f"Emitted bpf_probe_read_kernel_str (size={dst_size})")
return result, ir.IntType(64)
def handle_helper_call(
call,
module,

View File

@ -4,7 +4,6 @@ import logging
from llvmlite import ir
from pythonbpf.expr import (
get_operand_value,
eval_expr,
)
logger = logging.getLogger(__name__)
@ -137,140 +136,3 @@ def get_data_ptr_and_size(data_arg, local_sym_tab, struct_sym_tab):
raise NotImplementedError(
"Only simple object names are supported as data in perf event output."
)
def get_buffer_ptr_and_size(buf_arg, builder, local_sym_tab, struct_sym_tab):
"""Extract buffer pointer and size from either a struct field or variable."""
# Case 1: Struct field (obj.field)
if isinstance(buf_arg, ast.Attribute):
if not isinstance(buf_arg.value, ast.Name):
raise ValueError(
"Only simple struct field access supported (e.g., obj.field)"
)
struct_name = buf_arg.value.id
field_name = buf_arg.attr
# Lookup struct
if not local_sym_tab or struct_name not in local_sym_tab:
raise ValueError(f"Struct '{struct_name}' not found")
struct_type = local_sym_tab[struct_name].metadata
if not struct_sym_tab or struct_type not in struct_sym_tab:
raise ValueError(f"Struct type '{struct_type}' not found")
struct_info = struct_sym_tab[struct_type]
# Get field pointer and type
struct_ptr = local_sym_tab[struct_name].var
field_ptr = struct_info.gep(builder, struct_ptr, field_name)
field_type = struct_info.field_type(field_name)
if not isinstance(field_type, ir.ArrayType):
raise ValueError(f"Field '{field_name}' must be an array type")
return field_ptr, field_type.count
# Case 2: Variable name
elif isinstance(buf_arg, ast.Name):
var_name = buf_arg.id
if not local_sym_tab or var_name not in local_sym_tab:
raise ValueError(f"Variable '{var_name}' not found")
var_ptr = local_sym_tab[var_name].var
var_type = local_sym_tab[var_name].ir_type
if not isinstance(var_type, ir.ArrayType):
raise ValueError(f"Variable '{var_name}' must be an array type")
return var_ptr, var_type.count
else:
raise ValueError(
"comm expects either a struct field (obj.field) or variable name"
)
def get_char_array_ptr_and_size(buf_arg, builder, local_sym_tab, struct_sym_tab):
"""Get pointer to char array and its size."""
# Struct field: obj.field
if isinstance(buf_arg, ast.Attribute) and isinstance(buf_arg.value, ast.Name):
var_name = buf_arg.value.id
field_name = buf_arg.attr
if not (local_sym_tab and var_name in local_sym_tab):
raise ValueError(f"Variable '{var_name}' not found")
struct_type = local_sym_tab[var_name].metadata
if not (struct_sym_tab and struct_type in struct_sym_tab):
raise ValueError(f"Struct type '{struct_type}' not found")
struct_info = struct_sym_tab[struct_type]
if field_name not in struct_info.fields:
raise ValueError(f"Field '{field_name}' not found")
field_type = struct_info.field_type(field_name)
if not _is_char_array(field_type):
raise ValueError("Expected char array field")
struct_ptr = local_sym_tab[var_name].var
field_ptr = struct_info.gep(builder, struct_ptr, field_name)
# GEP to first element: [N x i8]* -> i8*
buf_ptr = builder.gep(
field_ptr,
[ir.Constant(ir.IntType(32), 0), ir.Constant(ir.IntType(32), 0)],
inbounds=True,
)
return buf_ptr, field_type.count
elif isinstance(buf_arg, ast.Name):
# NOTE: We shouldn't be doing this as we can't get size info
var_name = buf_arg.id
if not (local_sym_tab and var_name in local_sym_tab):
raise ValueError(f"Variable '{var_name}' not found")
var_ptr = local_sym_tab[var_name].var
var_type = local_sym_tab[var_name].ir_type
if not isinstance(var_type, ir.PointerType) and not isinstance(
var_type.pointee, ir.IntType(8)
):
raise ValueError("Expected str ptr variable")
return var_ptr, 256 # Size unknown for str ptr, using 256 as default
else:
raise ValueError("Expected struct field or variable name")
def _is_char_array(ir_type):
"""Check if IR type is [N x i8]."""
return (
isinstance(ir_type, ir.ArrayType)
and isinstance(ir_type.element, ir.IntType)
and ir_type.element.width == 8
)
def get_ptr_from_arg(
arg, func, module, builder, local_sym_tab, map_sym_tab, struct_sym_tab
):
"""Evaluate argument and return pointer value"""
result = eval_expr(
func, module, builder, arg, local_sym_tab, map_sym_tab, struct_sym_tab
)
if not result:
raise ValueError("Failed to evaluate argument")
val, val_type = result
if not isinstance(val_type, ir.PointerType):
raise ValueError(f"Expected pointer type, got {val_type}")
return val, val_type

View File

@ -2,31 +2,19 @@ import ctypes
def ktime():
"""get current ktime"""
return ctypes.c_int64(0)
def pid():
"""get current process id"""
return ctypes.c_int32(0)
def deref(ptr):
"""dereference a pointer"""
"dereference a pointer"
result = ctypes.cast(ptr, ctypes.POINTER(ctypes.c_void_p)).contents.value
return result if result is not None else 0
def comm(buf):
"""get current process command name"""
return ctypes.c_int64(0)
def probe_read_str(dst, src):
"""Safely read a null-terminated string from kernel memory"""
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

@ -173,15 +173,6 @@ def _populate_fval(ftype, node, fmt_parts, exprs):
raise NotImplementedError(
f"Unsupported pointer target type in f-string: {target}"
)
elif isinstance(ftype, ir.ArrayType):
if isinstance(ftype.element, ir.IntType) and ftype.element.width == 8:
# Char array
fmt_parts.append("%s")
exprs.append(node)
else:
raise NotImplementedError(
f"Unsupported array element type in f-string: {ftype.element}"
)
else:
raise NotImplementedError(f"Unsupported field type in f-string: {ftype}")
@ -206,100 +197,44 @@ def _create_format_string_global(fmt_str, func, module, builder):
def _prepare_expr_args(expr, func, module, builder, local_sym_tab, struct_sym_tab):
"""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_struct_char_array_ptr(
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)
if not val:
logger.warning("Failed to evaluate expression for bpf_printk, defaulting to 0")
return ir.Constant(ir.IntType(64), 0)
# Convert value to bpf_printk compatible type
if isinstance(val.type, ir.PointerType):
return _handle_pointer_arg(val, func, builder)
elif isinstance(val.type, ir.IntType):
return _handle_int_arg(val, builder)
else:
logger.warning(f"Unsupported type {val.type} in bpf_printk, defaulting to 0")
return ir.Constant(ir.IntType(64), 0)
def _get_struct_char_array_ptr(expr, builder, local_sym_tab, struct_sym_tab):
"""Get pointer to first element of char array in struct field, or None."""
if not (isinstance(expr, ast.Attribute) and isinstance(expr.value, ast.Name)):
return None
var_name = expr.value.id
field_name = expr.attr
# Check if it's a valid struct field
if not (
local_sym_tab
and var_name in local_sym_tab
and struct_sym_tab
and local_sym_tab[var_name].metadata in struct_sym_tab
):
return None
struct_type = local_sym_tab[var_name].metadata
struct_info = struct_sym_tab[struct_type]
if field_name not in struct_info.fields:
return None
field_type = struct_info.field_type(field_name)
# Check if it's a char array
is_char_array = (
isinstance(field_type, ir.ArrayType)
and isinstance(field_type.element, ir.IntType)
and field_type.element.width == 8
val, _ = eval_expr(
func,
module,
builder,
expr,
local_sym_tab,
None,
struct_sym_tab,
)
if not is_char_array:
return None
if val:
if isinstance(val.type, ir.PointerType):
target, depth = get_base_type_and_depth(val.type)
if isinstance(target, ir.IntType):
if target.width >= 32:
val = deref_to_depth(func, builder, val, depth)
val = builder.sext(val, ir.IntType(64))
elif target.width == 8 and depth == 1:
# NOTE: i8* is string, no need to deref
pass
# Get field pointer and GEP to first element: [N x i8]* -> i8*
struct_ptr = local_sym_tab[var_name].var
field_ptr = struct_info.gep(builder, struct_ptr, field_name)
return builder.gep(
field_ptr,
[ir.Constant(ir.IntType(32), 0), ir.Constant(ir.IntType(32), 0)],
inbounds=True,
)
def _handle_pointer_arg(val, func, builder):
"""Convert pointer type for bpf_printk."""
target, depth = get_base_type_and_depth(val.type)
if not isinstance(target, ir.IntType):
logger.warning("Only int pointers supported in bpf_printk, defaulting to 0")
return ir.Constant(ir.IntType(64), 0)
# i8* is string - use as-is
if target.width == 8 and depth == 1:
else:
logger.warning(
"Only int and ptr supported in bpf_printk args. Others default to 0."
)
val = ir.Constant(ir.IntType(64), 0)
elif isinstance(val.type, ir.IntType):
if val.type.width < 64:
val = builder.sext(val, ir.IntType(64))
else:
logger.warning(
"Only int and ptr supported in bpf_printk args. Others default to 0."
)
val = ir.Constant(ir.IntType(64), 0)
return val
# Integer pointers: dereference and sign-extend to i64
if target.width >= 32:
val = deref_to_depth(func, builder, val, depth)
return builder.sext(val, ir.IntType(64))
logger.warning("Unsupported pointer width in bpf_printk, defaulting to 0")
return ir.Constant(ir.IntType(64), 0)
def _handle_int_arg(val, builder):
"""Convert integer type for bpf_printk (sign-extend to i64)."""
if val.type.width < 64:
return builder.sext(val, ir.IntType(64))
return val
else:
logger.warning(
"Failed to evaluate expression for bpf_printk argument. "
"It will be converted to 0."
)
return ir.Constant(ir.IntType(64), 0)

View File

@ -1,56 +0,0 @@
import subprocess
def trace_pipe():
"""Util to read from the trace pipe."""
try:
subprocess.run(["cat", "/sys/kernel/tracing/trace_pipe"])
except KeyboardInterrupt:
print("Tracing stopped.")
def trace_fields():
"""Parse one line from trace_pipe into fields."""
with open("/sys/kernel/tracing/trace_pipe", "rb", buffering=0) as f:
while True:
line = f.readline().rstrip()
if not line:
continue
# Skip lost event lines
if line.startswith(b"CPU:"):
continue
# Parse BCC-style: first 16 bytes = task
task = line[:16].lstrip().decode("utf-8")
line = line[17:] # Skip past task field and space
# Find the colon that ends "pid cpu flags timestamp"
ts_end = line.find(b":")
if ts_end == -1:
raise ValueError("Cannot parse trace line")
# Split "pid [cpu] flags timestamp"
try:
parts = line[:ts_end].split()
if len(parts) < 4:
raise ValueError("Not enough fields")
pid = int(parts[0])
cpu = parts[1][1:-1] # Remove brackets from [cpu]
cpu = int(cpu)
flags = parts[2]
ts = float(parts[3])
except (ValueError, IndexError):
raise ValueError("Cannot parse trace line")
# Get message: skip ": symbol:" part
line = line[ts_end + 1 :] # Skip first ":"
sym_end = line.find(b":")
if sym_end != -1:
msg = line[sym_end + 2 :].decode("utf-8") # Skip ": " after symbol
else:
msg = line.lstrip().decode("utf-8")
return (task, pid, cpu, flags, ts, msg)

View File

@ -60,6 +60,10 @@ def process_vmlinux_post_ast(
pass
else:
new_dep_node = DependencyNode(name=current_symbol_name)
# elem_type_class is the actual vmlinux struct/class
new_dep_node.set_ctype_struct(elem_type_class)
handler.add_node(new_dep_node)
class_obj = getattr(imported_module, current_symbol_name)
# Inspect the class fields
@ -112,7 +116,11 @@ def process_vmlinux_post_ast(
type_length = elem_type._length_
if containing_type.__module__ == "vmlinux":
pass
new_dep_node.add_dependent(
elem_type._type_.__name__
if hasattr(elem_type._type_, "__name__")
else str(elem_type._type_)
)
elif containing_type.__module__ == ctypes.__name__:
if isinstance(elem_type, type):
if issubclass(elem_type, ctypes.Array):
@ -137,10 +145,35 @@ def process_vmlinux_post_ast(
)
new_dep_node.set_field_type(elem_name, elem_type)
if containing_type.__module__ == "vmlinux":
process_vmlinux_post_ast(
containing_type, llvm_handler, handler, processing_stack
containing_type_name = (
containing_type.__name__
if hasattr(containing_type, "__name__")
else str(containing_type)
)
new_dep_node.set_field_ready(elem_name, True)
# 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}")
new_dep_node.set_field_ready(elem_name, True)
@ -149,6 +182,11 @@ def process_vmlinux_post_ast(
"Module not supported in recursive resolution"
)
else:
new_dep_node.add_dependent(
elem_type.__name__
if hasattr(elem_type, "__name__")
else str(elem_type)
)
process_vmlinux_post_ast(
elem_type, llvm_handler, handler, processing_stack
)

View File

@ -147,3 +147,27 @@ class DependencyHandler:
int: The number of nodes
"""
return len(self._nodes)
def __getitem__(self, name: str) -> DependencyNode:
"""
Get a node by name using dictionary-style access.
Args:
name: The name of the node to retrieve
Returns:
DependencyNode: The node with the given name
Raises:
KeyError: If no node with the given name exists
Example:
node = handler["some-dep_node_name"]
"""
if name not in self._nodes:
raise KeyError(f"No node with name '{name}' found")
return self._nodes[name]
@property
def nodes(self):
return self._nodes

View File

@ -1,5 +1,6 @@
from dataclasses import dataclass, field
from typing import Dict, Any, Optional
import ctypes
# TODO: FIX THE FUCKING TYPE NAME CONVENTION.
@ -13,6 +14,7 @@ class Field:
containing_type: Optional[Any]
type_size: Optional[int]
bitfield_size: Optional[int]
offset: int
value: Any = None
ready: bool = False
@ -60,6 +62,10 @@ class Field:
if mark_ready:
self.ready = True
def set_offset(self, offset: int) -> None:
"""Set the offset of this field"""
self.offset = offset
@dataclass
class DependencyNode:
@ -106,8 +112,11 @@ class DependencyNode:
"""
name: str
depends_on: Optional[list[str]] = None
fields: Dict[str, Field] = field(default_factory=dict)
_ready_cache: Optional[bool] = field(default=None, repr=False)
current_offset: int = 0
ctype_struct: Optional[Any] = field(default=None, repr=False)
def add_field(
self,
@ -119,8 +128,11 @@ class DependencyNode:
ctype_complex_type: Optional[int] = None,
bitfield_size: Optional[int] = None,
ready: bool = False,
offset: int = 0,
) -> None:
"""Add a field to the node with an optional initial value and readiness state."""
if self.depends_on is None:
self.depends_on = []
self.fields[name] = Field(
name=name,
type=field_type,
@ -130,10 +142,21 @@ class DependencyNode:
type_size=type_size,
ctype_complex_type=ctype_complex_type,
bitfield_size=bitfield_size,
offset=offset,
)
# Invalidate readiness cache
self._ready_cache = None
def set_ctype_struct(self, ctype_struct: Any) -> None:
"""Set the ctypes structure for automatic offset calculation."""
self.ctype_struct = ctype_struct
def __sizeof__(self):
# If we have a ctype_struct, use its size
if self.ctype_struct is not None:
return ctypes.sizeof(self.ctype_struct)
return self.current_offset
def get_field(self, name: str) -> Field:
"""Get a field by name."""
return self.fields[name]
@ -200,15 +223,112 @@ class DependencyNode:
# Invalidate readiness cache
self._ready_cache = None
def set_field_ready(self, name: str, is_ready: bool = False) -> None:
def set_field_ready(
self,
name: str,
is_ready: bool = False,
size_of_containing_type: Optional[int] = None,
) -> None:
"""Mark a field as ready or not ready."""
if name not in self.fields:
raise KeyError(f"Field '{name}' does not exist in node '{self.name}'")
self.fields[name].set_ready(is_ready)
# Use ctypes built-in offset if available
if self.ctype_struct is not None:
try:
self.fields[name].set_offset(getattr(self.ctype_struct, name).offset)
except AttributeError:
# Fallback to manual calculation if field not found in ctype_struct
self.fields[name].set_offset(self.current_offset)
self.current_offset += self._calculate_size(
name, size_of_containing_type
)
else:
# Manual offset calculation when no ctype_struct is available
self.fields[name].set_offset(self.current_offset)
self.current_offset += self._calculate_size(name, size_of_containing_type)
# Invalidate readiness cache
self._ready_cache = None
def _calculate_size(
self, name: str, size_of_containing_type: Optional[int] = None
) -> int:
processing_field = self.fields[name]
# size_of_field will be in bytes
if processing_field.type.__module__ == ctypes.__name__:
size_of_field = ctypes.sizeof(processing_field.type)
return size_of_field
elif processing_field.type.__module__ == "vmlinux":
if processing_field.ctype_complex_type is not None:
if issubclass(processing_field.ctype_complex_type, ctypes.Array):
if processing_field.containing_type.__module__ == ctypes.__name__:
if (
processing_field.containing_type is not None
and processing_field.type_size is not None
):
size_of_field = (
ctypes.sizeof(processing_field.containing_type)
* processing_field.type_size
)
else:
raise RuntimeError(
f"{processing_field} has no containing_type or type_size"
)
return size_of_field
elif processing_field.containing_type.__module__ == "vmlinux":
if (
size_of_containing_type is not None
and processing_field.type_size is not None
):
size_of_field = (
size_of_containing_type * processing_field.type_size
)
else:
raise RuntimeError(
f"{processing_field} has no containing_type or type_size"
)
return size_of_field
elif issubclass(processing_field.ctype_complex_type, ctypes._Pointer):
return ctypes.sizeof(ctypes.c_void_p)
else:
raise NotImplementedError(
"This subclass of ctype not supported yet"
)
elif processing_field.type_size is not None:
# Handle vmlinux types with type_size but no ctype_complex_type
# This means it's a direct vmlinux struct field (not array/pointer wrapped)
# The type_size should already contain the full size of the struct
# But if there's a containing_type from vmlinux, we need that size
if processing_field.containing_type is not None:
if processing_field.containing_type.__module__ == "vmlinux":
# For vmlinux containing types, we need the pre-calculated size
if size_of_containing_type is not None:
return size_of_containing_type * processing_field.type_size
else:
raise RuntimeError(
f"Field {name}: vmlinux containing_type requires size_of_containing_type"
)
else:
raise ModuleNotFoundError(
f"Containing type module {processing_field.containing_type.__module__} not supported"
)
else:
raise RuntimeError("Wrong type found with no containing type")
else:
# No ctype_complex_type and no type_size, must rely on size_of_containing_type
if size_of_containing_type is None:
raise RuntimeError(
f"Size of containing type {size_of_containing_type} is None"
)
return size_of_containing_type
else:
raise ModuleNotFoundError("Module is not supported for the operation")
raise RuntimeError("control should not reach here")
@property
def is_ready(self) -> bool:
"""Check if the node is ready (all fields are ready)."""
@ -235,3 +355,9 @@ class DependencyNode:
def get_not_ready_fields(self) -> Dict[str, Field]:
"""Get all fields that are marked as not ready."""
return {name: elem for name, elem in self.fields.items() if not elem.ready}
def add_dependent(self, dep_type):
if dep_type in self.depends_on:
return
else:
self.depends_on.append(dep_type)

View File

@ -1,11 +1,11 @@
import ast
import logging
from typing import List, Tuple, Dict
from typing import List, Tuple, Any
import importlib
import inspect
from .dependency_handler import DependencyHandler
from .ir_generation import IRGenerator
from .ir_gen import IRGenerator
from .class_handler import process_vmlinux_class
logger = logging.getLogger(__name__)
@ -82,7 +82,7 @@ def vmlinux_proc(tree: ast.AST, module):
# initialise dependency handler
handler = DependencyHandler()
# initialise assignment dictionary of name to type
assignments: Dict[str, type] = {}
assignments: dict[str, tuple[type, Any]] = {}
if not import_statements:
logger.info("No vmlinux imports found")
@ -129,7 +129,19 @@ def vmlinux_proc(tree: ast.AST, module):
)
IRGenerator(module, handler)
return assignments
def process_vmlinux_assign(node, module, assignments: Dict[str, type]):
raise NotImplementedError("Assignment handling has not been implemented yet")
def process_vmlinux_assign(node, module, assignments: dict[str, tuple[type, Any]]):
# Check if this is a simple assignment with a constant value
if len(node.targets) == 1 and isinstance(node.targets[0], ast.Name):
target_name = node.targets[0].id
if isinstance(node.value, ast.Constant):
assignments[target_name] = (type(node.value.value), node.value.value)
logger.info(
f"Added assignment: {target_name} = {node.value.value!r} of type {type(node.value.value)}"
)
else:
raise ValueError(f"Unsupported assignment type for {target_name}")
else:
raise ValueError("Not a simple assignment")

View File

@ -0,0 +1,3 @@
from .ir_generation import IRGenerator
__all__ = ["IRGenerator"]

View File

@ -0,0 +1,15 @@
from pythonbpf.debuginfo import DebugInfoGenerator
def debug_info_generation(struct, llvm_module):
generator = DebugInfoGenerator(llvm_module)
# this is sample debug info generation
# i64type = generator.get_uint64_type()
struct_type = generator.create_struct_type([], 64 * 4, is_distinct=True)
global_var = generator.create_global_var_debug_info(
struct.name, struct_type, is_local=False
)
return global_var

View File

@ -0,0 +1,161 @@
import ctypes
import logging
from ..dependency_handler import DependencyHandler
from .debug_info_gen import debug_info_generation
from ..dependency_node import DependencyNode
import llvmlite.ir as ir
logger = logging.getLogger(__name__)
class IRGenerator:
# get the assignments dict and add this stuff to it.
def __init__(self, llvm_module, handler: DependencyHandler, assignment=None):
self.llvm_module = llvm_module
self.handler: DependencyHandler = handler
self.generated: list[str] = []
if not handler.is_ready:
raise ImportError(
"Semantic analysis of vmlinux imports failed. Cannot generate IR"
)
for struct in handler:
self.struct_processor(struct)
def struct_processor(self, struct, processing_stack=None):
# Initialize processing stack on first call
if processing_stack is None:
processing_stack = set()
# If already generated, skip
if struct.name in self.generated:
return
# Detect circular dependency
if struct.name in processing_stack:
logger.info(
f"Circular dependency detected for {struct.name}, skipping recursive processing"
)
# For circular dependencies, we can either:
# 1. Use forward declarations (opaque pointers)
# 2. Mark as incomplete and process later
# 3. Generate a placeholder type
# Here we'll just skip and let it be processed in its own call
return
logger.info(f"IR generating for {struct.name}")
# Add to processing stack before processing dependencies
processing_stack.add(struct.name)
try:
# Process all dependencies first
if struct.depends_on is None:
pass
else:
for dependency in struct.depends_on:
if dependency not in self.generated:
# Check if dependency exists in handler
if dependency in self.handler.nodes:
dep_node_from_dependency = self.handler[dependency]
# Pass the processing_stack down to track circular refs
self.struct_processor(
dep_node_from_dependency, processing_stack
)
else:
raise RuntimeError(
f"Warning: Dependency {dependency} not found in handler"
)
# Actual processor logic here after dependencies are resolved
self.gen_ir(struct)
self.generated.append(struct.name)
finally:
# Remove from processing stack after we're done
processing_stack.discard(struct.name)
def gen_ir(self, struct):
# TODO: we add the btf_ama attribute by monkey patching in the end of compilation, but once llvmlite
# accepts our issue, we will resort to normal accessed attribute based attribute addition
# currently we generate all possible field accesses for CO-RE and put into the assignment table
debug_info = debug_info_generation(struct, self.llvm_module)
field_index = 0
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(
field.ctype_complex_type, ctypes.Array
):
array_size = field.type_size
containing_type = field.containing_type
if containing_type.__module__ == ctypes.__name__:
containing_type_size = ctypes.sizeof(containing_type)
for i in range(0, array_size):
field_co_re_name = 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)
field_index += 1
elif field.type_size is not None:
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
)
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)
field_index += 1
else:
field_co_re_name = 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)
def _struct_name_generator(
self,
struct: DependencyNode,
field,
field_index: int,
is_indexed: bool = False,
index: int = 0,
containing_type_size: int = 0,
) -> str:
if is_indexed:
name = (
"llvm."
+ struct.name.removeprefix("struct_")
+ f":0:{field.offset + index * containing_type_size}"
+ "$"
+ f"0:{field_index}:{index}"
)
return name
elif struct.name.startswith("struct_"):
name = (
"llvm."
+ struct.name.removeprefix("struct_")
+ f":0:{field.offset}"
+ "$"
+ f"0:{field_index}"
)
return name
else:
print(self.handler[struct.name])
raise TypeError(
"Name generation cannot occur due to type name not starting with struct"
)

View File

@ -1,14 +0,0 @@
import logging
from .dependency_handler import DependencyHandler
logger = logging.getLogger(__name__)
class IRGenerator:
def __init__(self, module, handler: DependencyHandler):
self.module = module
self.handler: DependencyHandler = handler
if not handler.is_ready:
raise ImportError(
"Semantic analysis of vmlinux imports failed. Cannot generate IR"
)

View File

@ -1,23 +1,9 @@
// SPDX-License-Identifier: GPL-2.0
#include <linux/bpf.h>
#include "vmlinux.h"
#include <bpf/bpf_helpers.h>
#include <bpf/bpf_tracing.h>
struct trace_entry {
short unsigned int type;
unsigned char flags;
unsigned char preempt_count;
int pid;
};
struct trace_event_raw_sys_enter {
struct trace_entry ent;
long int id;
long unsigned int args[6];
char __data[0];
};
struct event {
__u32 pid;
__u32 uid;

View File

@ -1,10 +1,17 @@
from pythonbpf import bpf, map, section, bpfglobal, compile_to_ir
from pythonbpf.maps import HashMap
from pythonbpf.helper import XDP_PASS
from vmlinux import struct_xdp_md
from vmlinux import struct_xdp_buff # noqa: F401
from vmlinux import struct_ring_buffer_per_cpu # noqa: F401
from vmlinux import TASK_COMM_LEN # noqa: F401
from vmlinux import struct_qspinlock # noqa: F401
# from vmlinux import struct_trace_event_raw_sys_enter # noqa: F401
# from vmlinux import struct_posix_cputimers # noqa: F401
from vmlinux import struct_xdp_md
# from vmlinux import struct_trace_event_raw_sys_enter # noqa: F401
# from vmlinux import struct_ring_buffer_per_cpu # noqa: F401
# from vmlinux import struct_request # noqa: F401
from ctypes import c_int64
# Instructions to how to run this program

View File

@ -1,28 +0,0 @@
from pythonbpf import bpf, struct, section, bpfglobal
from pythonbpf.helper import comm
from ctypes import c_void_p, c_int64
@bpf
@struct
class data_t:
comm: str(16) # type: ignore [valid-type]
copp: str(16) # type: ignore [valid-type]
@bpf
@section("tracepoint/syscalls/sys_enter_clone")
def hello(ctx: c_void_p) -> c_int64:
dataobj = data_t()
comm(dataobj.comm)
strobj = dataobj.comm
dataobj.copp = strobj
print(f"clone called by comm {dataobj.copp}")
return 0
@bpf
@bpfglobal
def LICENSE() -> str:
return "GPL"

View File

@ -1,26 +0,0 @@
from pythonbpf import bpf, struct, section, bpfglobal
from pythonbpf.helper import comm
from ctypes import c_void_p, c_int64
@bpf
@struct
class data_t:
comm: str(16) # type: ignore [valid-type]
@bpf
@section("tracepoint/syscalls/sys_enter_clone")
def hello(ctx: c_void_p) -> c_int64:
dataobj = data_t()
comm(dataobj.comm)
strobj = dataobj.comm
print(f"clone called by comm {strobj}")
return 0
@bpf
@bpfglobal
def LICENSE() -> str:
return "GPL"