26 Commits

Author SHA1 Message Date
00ce3014dc Initial plan 2025-11-20 08:37:10 +00:00
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
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
17 changed files with 562 additions and 63 deletions

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

@ -7,6 +7,7 @@ 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__)
@ -25,7 +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)}")
@ -55,7 +58,9 @@ def handle_assign_allocation(builder, stmt, local_sym_tab, structs_sym_tab):
# 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):
@ -74,7 +79,9 @@ 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):
@ -116,15 +123,74 @@ def _allocate_for_call(builder, var_name, rval, local_sym_tab, structs_sym_tab):
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)
@ -135,7 +201,9 @@ 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):

View File

@ -86,7 +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)
@ -218,13 +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)

View File

@ -147,7 +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)

View File

@ -12,6 +12,7 @@ from .helpers import (
smp_processor_id,
uid,
skb_store_bytes,
get_stack,
XDP_DROP,
XDP_PASS,
)
@ -83,6 +84,7 @@ __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 +32,12 @@ 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_RINGBUF_OUTPUT = 130
BPF_RINGBUF_RESERVE = 131
BPF_RINGBUF_SUBMIT = 132
BPF_RINGBUF_DISCARD = 133
@HelperHandlerRegistry.register(
@ -358,11 +362,6 @@ 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 +372,10 @@ 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 +413,98 @@ 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"""
@ -711,7 +806,10 @@ 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 +834,170 @@ 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 +1052,6 @@ 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)

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

@ -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()