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revert struct reference pointer sizes to i8 to ensure that compiler does not optimize

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varun-r-mallya
2025-10-27 03:28:16 +05:30
parent ac74b03b14
commit 07580dabf2
3 changed files with 13 additions and 14 deletions
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2
pythonbpf/codegen.py
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@ -39,7 +39,7 @@ def finalize_module(original_str):
def bpf_passthrough_gen(module): def bpf_passthrough_gen(module):
i32_ty = ir.IntType(32) i32_ty = ir.IntType(32)
ptr_ty = ir.PointerType(ir.IntType(64)) ptr_ty = ir.PointerType(ir.IntType(8))
fnty = ir.FunctionType(ptr_ty, [i32_ty, ptr_ty]) fnty = ir.FunctionType(ptr_ty, [i32_ty, ptr_ty])
# Declare the intrinsic # Declare the intrinsic

21
pythonbpf/vmlinux_parser/vmlinux_exports_handler.py
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@ -97,7 +97,7 @@ class VmlinuxHandler:
globvar_ir, field_data = self.get_field_type( globvar_ir, field_data = self.get_field_type(
python_type.__name__, field_name python_type.__name__, field_name
) )
builder.function.args[0].type = ir.PointerType(ir.IntType(64)) builder.function.args[0].type = ir.PointerType(ir.IntType(8))
print(builder.function.args[0]) print(builder.function.args[0])
field_ptr = self.load_ctx_field( field_ptr = self.load_ctx_field(
builder, builder.function.args[0], globvar_ir builder, builder.function.args[0], globvar_ir
@ -125,19 +125,18 @@ class VmlinuxHandler:
# Load the offset value # Load the offset value
offset = builder.load(offset_global) offset = builder.load(offset_global)
# # Ensure ctx_arg is treated as i8* (byte pointer) # Ensure ctx_arg is treated as i8* (byte pointer)
# # i8_type = ir.IntType(8) i8_ptr_type = ir.PointerType()
# i8_ptr_type = ir.PointerType()
# Cast ctx_arg to i8* if it isn't already # Cast ctx_arg to i8* if it isn't already
# if str(ctx_arg.type) != str(i8_ptr_type): if str(ctx_arg.type) != str(i8_ptr_type):
# ctx_i8_ptr = builder.bitcast(ctx_arg, i8_ptr_type) ctx_i8_ptr = builder.bitcast(ctx_arg, i8_ptr_type)
# else: else:
# ctx_i8_ptr = ctx_arg ctx_i8_ptr = ctx_arg
# GEP with explicit type - this is the key fix # GEP with explicit type - this is the key fix
field_ptr = builder.gep( field_ptr = builder.gep(
ctx_arg, ctx_i8_ptr,
[offset], [offset],
inbounds=False, inbounds=False,
) )
@ -151,8 +150,8 @@ class VmlinuxHandler:
raise KeyError raise KeyError
except (KeyError, AttributeError): except (KeyError, AttributeError):
passthrough_type = ir.FunctionType( passthrough_type = ir.FunctionType(
ir.PointerType(), i8_ptr_type,
[ir.IntType(32), ir.PointerType()], [ir.IntType(32), i8_ptr_type],
) )
passthrough_fn = ir.Function( passthrough_fn = ir.Function(
module, module,

4
tests/failing_tests/vmlinux/struct_field_access.py
View File

@ -13,10 +13,10 @@ from ctypes import c_int64, c_int32, c_void_p # noqa: F401
@bpf @bpf
@section("tracepoint/syscalls/sys_enter_execve") @section("tracepoint/syscalls/sys_enter_execve")
def hello_world(ctx: struct_trace_event_raw_sys_enter) -> c_int32: def hello_world(ctx: struct_trace_event_raw_sys_enter) -> c_int64:
b = ctx.id b = ctx.id
print(f"This is context field {b}") print(f"This is context field {b}")
return c_int32(0) return c_int64(0)
@bpf @bpf