Commit 3fcd50d6 authored by Ilya Leoshkevich's avatar Ilya Leoshkevich Committed by Alexei Starovoitov
Browse files

selftests/bpf: Add BTF_KIND_FLOAT to test_core_reloc_size 



Verify that bpf_core_field_size() is working correctly with floats.
Also document the required clang version.

Suggested-by: default avatarJohn Fastabend <john.fastabend@gmail.com>
Signed-off-by: default avatarIlya Leoshkevich <iii@linux.ibm.com>
Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20210309005649.162480-2-iii@linux.ibm.com
parent a0d73acc

tools/testing/selftests/bpf/README.rst

+9 −0
Original line number Diff line number Diff line
@@ -170,3 +170,12 @@ failures: 
.. _2: https://reviews.llvm.org/D85174

.. _3: https://reviews.llvm.org/D83878

.. _4: https://reviews.llvm.org/D83242



Floating-point tests and Clang version

======================================



Certain selftests, e.g. core_reloc, require support for the floating-point

types, which was introduced in `Clang 13`__. The older Clang versions will

either crash when compiling these tests, or generate an incorrect BTF.



__  https://reviews.llvm.org/D83289

tools/testing/selftests/bpf/prog_tests/core_reloc.c

+1 −0
Original line number Diff line number Diff line
@@ -266,6 +266,7 @@ static int duration = 0; 
		.arr_elem_sz = sizeof(((type *)0)->arr_field[0]),	\

		.ptr_sz = 8, /* always 8-byte pointer for BPF */	\

		.enum_sz = sizeof(((type *)0)->enum_field),		\

		.float_sz = sizeof(((type *)0)->float_field),		\

	}



#define SIZE_CASE(name) {						\

tools/testing/selftests/bpf/progs/core_reloc_types.h

+5 −0
Original line number Diff line number Diff line
@@ -807,6 +807,7 @@ struct core_reloc_size_output { 
	int arr_elem_sz;

	int ptr_sz;

	int enum_sz;

	int float_sz;

};



struct core_reloc_size {
@@ -816,6 +817,7 @@ struct core_reloc_size { 
	int arr_field[4];

	void *ptr_field;

	enum { VALUE = 123 } enum_field;

	float float_field;

};



struct core_reloc_size___diff_sz {
@@ -825,6 +827,7 @@ struct core_reloc_size___diff_sz { 
	char arr_field[10];

	void *ptr_field;

	enum { OTHER_VALUE = 0xFFFFFFFFFFFFFFFF } enum_field;

	double float_field;

};



/* Error case of two candidates with the fields (int_field) at the same
@@ -839,6 +842,7 @@ struct core_reloc_size___err_ambiguous1 { 
	int arr_field[4];

	void *ptr_field;

	enum { VALUE___1 = 123 } enum_field;

	float float_field;

};



struct core_reloc_size___err_ambiguous2 {
@@ -850,6 +854,7 @@ struct core_reloc_size___err_ambiguous2 { 
	int arr_field[4];

	void *ptr_field;

	enum { VALUE___2 = 123 } enum_field;

	float float_field;

};



/*

tools/testing/selftests/bpf/progs/test_core_reloc_size.c

+3 −0
Original line number Diff line number Diff line
@@ -21,6 +21,7 @@ struct core_reloc_size_output { 
	int arr_elem_sz;

	int ptr_sz;

	int enum_sz;

	int float_sz;

};



struct core_reloc_size {
@@ -30,6 +31,7 @@ struct core_reloc_size { 
	int arr_field[4];

	void *ptr_field;

	enum { VALUE = 123 } enum_field;

	float float_field;

};



SEC("raw_tracepoint/sys_enter")
@@ -45,6 +47,7 @@ int test_core_size(void *ctx) 
	out->arr_elem_sz = bpf_core_field_size(in->arr_field[0]);

	out->ptr_sz = bpf_core_field_size(in->ptr_field);

	out->enum_sz = bpf_core_field_size(in->enum_field);

	out->float_sz = bpf_core_field_size(in->float_field);



	return 0;

}