Commit d19ddb47 authored by Song Liu's avatar Song Liu Committed by Alexei Starovoitov
Browse files

bpf: Introduce btf_tracing_ids 



Similar to btf_sock_ids, btf_tracing_ids provides btf ID for task_struct,
file, and vm_area_struct via easy to understand format like
btf_tracing_ids[BTF_TRACING_TYPE_[TASK|file|VMA]].

Suggested-by: default avatarAlexei Starovoitov <ast@kernel.org>
Signed-off-by: default avatarSong Liu <songliubraving@fb.com>
Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
Acked-by: default avatarYonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20211112150243.1270987-3-songliubraving@fb.com
parent 9e2ad638

include/linux/btf_ids.h

+13 −1
Original line number Diff line number Diff line
@@ -189,6 +189,18 @@ MAX_BTF_SOCK_TYPE, 
extern u32 btf_sock_ids[];

#endif



extern u32 btf_task_struct_ids[];

#define BTF_TRACING_TYPE_xxx	\

	BTF_TRACING_TYPE(BTF_TRACING_TYPE_TASK, task_struct)	\

	BTF_TRACING_TYPE(BTF_TRACING_TYPE_FILE, file)		\

	BTF_TRACING_TYPE(BTF_TRACING_TYPE_VMA, vm_area_struct)



enum {

#define BTF_TRACING_TYPE(name, type) name,

BTF_TRACING_TYPE_xxx

#undef BTF_TRACING_TYPE

MAX_BTF_TRACING_TYPE,

};



extern u32 btf_tracing_ids[];



#endif

kernel/bpf/bpf_task_storage.c

+2 −2
Original line number Diff line number Diff line
@@ -323,7 +323,7 @@ const struct bpf_func_proto bpf_task_storage_get_proto = { 
	.ret_type = RET_PTR_TO_MAP_VALUE_OR_NULL,

	.arg1_type = ARG_CONST_MAP_PTR,

	.arg2_type = ARG_PTR_TO_BTF_ID,

	.arg2_btf_id = &btf_task_struct_ids[0],

	.arg2_btf_id = &btf_tracing_ids[BTF_TRACING_TYPE_TASK],

	.arg3_type = ARG_PTR_TO_MAP_VALUE_OR_NULL,

	.arg4_type = ARG_ANYTHING,

};
@@ -334,5 +334,5 @@ const struct bpf_func_proto bpf_task_storage_delete_proto = { 
	.ret_type = RET_INTEGER,

	.arg1_type = ARG_CONST_MAP_PTR,

	.arg2_type = ARG_PTR_TO_BTF_ID,

	.arg2_btf_id = &btf_task_struct_ids[0],

	.arg2_btf_id = &btf_tracing_ids[BTF_TRACING_TYPE_TASK],

};

kernel/bpf/btf.c

+4 −4
Original line number Diff line number Diff line
@@ -6354,10 +6354,10 @@ const struct bpf_func_proto bpf_btf_find_by_name_kind_proto = { 
	.arg4_type	= ARG_ANYTHING,

};



BTF_ID_LIST_GLOBAL(btf_task_struct_ids, 3)

BTF_ID(struct, task_struct)

BTF_ID(struct, file)

BTF_ID(struct, vm_area_struct)

BTF_ID_LIST_GLOBAL(btf_tracing_ids, MAX_BTF_TRACING_TYPE)

#define BTF_TRACING_TYPE(name, type) BTF_ID(struct, type)

BTF_TRACING_TYPE_xxx

#undef BTF_TRACING_TYPE



/* BTF ID set registration API for modules */

kernel/bpf/stackmap.c

+1 −1
Original line number Diff line number Diff line
@@ -489,7 +489,7 @@ const struct bpf_func_proto bpf_get_task_stack_proto = { 
	.gpl_only	= false,

	.ret_type	= RET_INTEGER,

	.arg1_type	= ARG_PTR_TO_BTF_ID,

	.arg1_btf_id	= &btf_task_struct_ids[0],

	.arg1_btf_id	= &btf_tracing_ids[BTF_TRACING_TYPE_TASK],

	.arg2_type	= ARG_PTR_TO_UNINIT_MEM,

	.arg3_type	= ARG_CONST_SIZE_OR_ZERO,

	.arg4_type	= ARG_ANYTHING,

kernel/bpf/task_iter.c

+6 −6
Original line number Diff line number Diff line
@@ -622,7 +622,7 @@ const struct bpf_func_proto bpf_find_vma_proto = { 
	.func		= bpf_find_vma,

	.ret_type	= RET_INTEGER,

	.arg1_type	= ARG_PTR_TO_BTF_ID,

	.arg1_btf_id	= &btf_task_struct_ids[0],

	.arg1_btf_id	= &btf_tracing_ids[BTF_TRACING_TYPE_TASK],

	.arg2_type	= ARG_ANYTHING,

	.arg3_type	= ARG_PTR_TO_FUNC,

	.arg4_type	= ARG_PTR_TO_STACK_OR_NULL,
@@ -652,19 +652,19 @@ static int __init task_iter_init(void) 
		init_irq_work(&work->irq_work, do_mmap_read_unlock);

	}



	task_reg_info.ctx_arg_info[0].btf_id = btf_task_struct_ids[0];

	task_reg_info.ctx_arg_info[0].btf_id = btf_tracing_ids[BTF_TRACING_TYPE_TASK];

	ret = bpf_iter_reg_target(&task_reg_info);

	if (ret)

		return ret;



	task_file_reg_info.ctx_arg_info[0].btf_id = btf_task_struct_ids[0];

	task_file_reg_info.ctx_arg_info[1].btf_id = btf_task_struct_ids[1];

	task_file_reg_info.ctx_arg_info[0].btf_id = btf_tracing_ids[BTF_TRACING_TYPE_TASK];

	task_file_reg_info.ctx_arg_info[1].btf_id = btf_tracing_ids[BTF_TRACING_TYPE_FILE];

	ret =  bpf_iter_reg_target(&task_file_reg_info);

	if (ret)

		return ret;



	task_vma_reg_info.ctx_arg_info[0].btf_id = btf_task_struct_ids[0];

	task_vma_reg_info.ctx_arg_info[1].btf_id = btf_task_struct_ids[2];

	task_vma_reg_info.ctx_arg_info[0].btf_id = btf_tracing_ids[BTF_TRACING_TYPE_TASK];

	task_vma_reg_info.ctx_arg_info[1].btf_id = btf_tracing_ids[BTF_TRACING_TYPE_VMA];

	return bpf_iter_reg_target(&task_vma_reg_info);

}

late_initcall(task_iter_init);