69 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
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
44 changed files with 1547 additions and 121801 deletions

2
.gitattributes vendored
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@ -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
@ -138,15 +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)
@ -157,7 +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):
@ -264,8 +310,91 @@ 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:
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
# TODO: For now, we only support integer type allocations.
# This always assumes first argument of function to be the context struct
base_ptr = builder.function.args[0]
local_sym_tab[
struct_var
].var = base_ptr # This is repurposing of var to store the pointer of the base type
local_sym_tab[struct_var].ir_type = field_ir
# 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, not the GlobalVariable
var = _allocate_with_type(builder, var_name, actual_ir_type)
local_sym_tab[var_name] = LocalSymbol(var, actual_ir_type, field)
logger.info(
f"Pre-allocated {var_name} from vmlinux struct {vmlinux_struct_name}.{field_name}"
)
return
else:
logger.error(f"Struct type '{struct_type}' not found")
return

View File

@ -3,6 +3,8 @@ import logging
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__)
@ -148,7 +150,33 @@ def handle_variable_assignment(
val, val_type = val_result
logger.info(f"Evaluated value for {var_name}: {val} of type {val_type}, {var_type}")
if val_type != var_type:
if isinstance(val_type, ir.IntType) and isinstance(var_type, ir.IntType):
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

@ -12,6 +12,7 @@ from .type_normalization import (
get_base_type_and_depth,
deref_to_depth,
)
from pythonbpf.vmlinux_parser.assignment_info import Field
from .vmlinux_registry import VmlinuxHandlerRegistry
logger: Logger = logging.getLogger(__name__)
@ -72,20 +73,28 @@ 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}")
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")
metadata = structs_sym_tab[var_metadata]
if 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 +280,45 @@ 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(

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

@ -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
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

@ -220,6 +220,7 @@ 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
if isinstance(expr, ast.Attribute):
char_array_ptr, _ = get_char_array_ptr_and_size(
expr, builder, local_sym_tab, 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)
result = _get_vmlinux_enum(handler, name)
params[keyword.arg] = result if result is not None else name
else:
params[keyword.arg] = 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 +13,11 @@ 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),
"c_int": 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

@ -86,19 +86,19 @@ 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)
@ -148,6 +148,7 @@ 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

@ -73,9 +73,8 @@ 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 +104,7 @@ 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}")

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 +79,177 @@ 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}"
)
python_type: type = var_info.metadata
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 pointer to field and field type
return None
return None
return field_ptr, field_data
else:
raise RuntimeError("Variable accessed not found in symbol table")
@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 +1,23 @@
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)
LL2 := $(SRC:.bpf.c=.bpf.o2.ll)
OBJ := $(SRC:.bpf.c=.bpf.o)
.PHONY: all clean
all: $(LL) $(OBJ)
all: $(LL) $(OBJ) $(LL2)
%.bpf.o: %.bpf.c
$(BPF_CLANG) -O2 -g -target bpf -c $< -o $@
%.bpf.ll: %.bpf.c
$(BPF_CLANG) $(CFLAGS) -g -S $< -o $@
$(BPF_CLANG) -O0 $(CFLAGS) -g -S $< -o $@
%.bpf.o2.ll: %.bpf.c
$(BPF_CLANG) -O2 $(CFLAGS) -g -S $< -o $@
clean:
rm -f $(LL) $(OBJ)
rm -f $(LL) $(OBJ) $(LL2)

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@ -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";

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@ -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;
}

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@ -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

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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";

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@ -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()

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@ -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)

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@ -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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@ -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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@ -0,0 +1,29 @@
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()