Merge branch 'introduce btf_tracing_ids'

Song Liu says:

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

Changes v2 => v3:
1. Fix bug in task_iter.c. (Kernel test robot <[e-mail]>)

Changes v1 => v2:
1. Add patch 2/2. (Alexei)

1/2 fixes issue with btf_task_struct_ids w/o CONFIG_DEBUG_INFO_BTF.
2/2 replaces btf_task_struct_ids with easier to understand btf_tracing_ids.
====================

Signed-off-by: Alexei Starovoitov <[e-mail]>

include/linux/btf_ids.h

···
 __BTF_ID_LIST(name, local)				\
 extern u32 name[];
 
-#define BTF_ID_LIST_GLOBAL(name)			\
+#define BTF_ID_LIST_GLOBAL(name, n)			\
 __BTF_ID_LIST(name, globl)
 
 /* The BTF_ID_LIST_SINGLE macro defines a BTF_ID_LIST with
···
 	BTF_ID_LIST(name) \
 	BTF_ID(prefix, typename)
 #define BTF_ID_LIST_GLOBAL_SINGLE(name, prefix, typename) \
-	BTF_ID_LIST_GLOBAL(name) \
+	BTF_ID_LIST_GLOBAL(name, 1)			  \
 	BTF_ID(prefix, typename)
 
 /*
···
 #define BTF_ID_LIST(name) static u32 name[5];
 #define BTF_ID(prefix, name)
 #define BTF_ID_UNUSED
-#define BTF_ID_LIST_GLOBAL(name) u32 name[1];
+#define BTF_ID_LIST_GLOBAL(name, n) u32 name[n];
 #define BTF_ID_LIST_SINGLE(name, prefix, typename) static u32 name[1];
 #define BTF_ID_LIST_GLOBAL_SINGLE(name, prefix, typename) u32 name[1];
 #define BTF_SET_START(name) static struct btf_id_set name = { 0 };
···
 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

···
 	.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,
 };
···
 	.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

···
 	.arg4_type	= ARG_ANYTHING,
 };
 
-BTF_ID_LIST_GLOBAL(btf_task_struct_ids)
-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

···
 	.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

···
 	.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,
···
 		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);

kernel/bpf/verifier.c

···
 	callee->regs[BPF_REG_2].type = PTR_TO_BTF_ID;
 	__mark_reg_known_zero(&callee->regs[BPF_REG_2]);
 	callee->regs[BPF_REG_2].btf =  btf_vmlinux;
-	callee->regs[BPF_REG_2].btf_id = btf_task_struct_ids[2];
+	callee->regs[BPF_REG_2].btf_id = btf_tracing_ids[BTF_TRACING_TYPE_VMA],
 
 	/* pointer to stack or null */
 	callee->regs[BPF_REG_3] = caller->regs[BPF_REG_4];

kernel/trace/bpf_trace.c

···
 	.func		= bpf_get_current_task_btf,
 	.gpl_only	= true,
 	.ret_type	= RET_PTR_TO_BTF_ID,
-	.ret_btf_id	= &btf_task_struct_ids[0],
+	.ret_btf_id	= &btf_tracing_ids[BTF_TRACING_TYPE_TASK],
 };
 
 BPF_CALL_1(bpf_task_pt_regs, struct task_struct *, task)
···
 	.func		= bpf_task_pt_regs,
 	.gpl_only	= true,
 	.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],
 	.ret_type	= RET_PTR_TO_BTF_ID,
 	.ret_btf_id	= &bpf_task_pt_regs_ids[0],
 };

net/core/filter.c

···
 	bpf_dispatcher_change_prog(BPF_DISPATCHER_PTR(xdp), prev_prog, prog);
 }
 
-#ifdef CONFIG_DEBUG_INFO_BTF
-BTF_ID_LIST_GLOBAL(btf_sock_ids)
+BTF_ID_LIST_GLOBAL(btf_sock_ids, MAX_BTF_SOCK_TYPE)
 #define BTF_SOCK_TYPE(name, type) BTF_ID(struct, type)
 BTF_SOCK_TYPE_xxx
 #undef BTF_SOCK_TYPE
-#else
-u32 btf_sock_ids[MAX_BTF_SOCK_TYPE];
-#endif
 
 BPF_CALL_1(bpf_skc_to_tcp6_sock, struct sock *, sk)
 {