[PATCH bpf-next v4 09/12] bpf, trace, net: prepare CONFIG_DEBUG_INFO_BTF checks for a tristate
HOTtoday
From: Jay Wang <hidden>
Date: 2026-10-01 22:54:42
Also in:
bpf, linux-doc, linux-input, linux-kbuild, linux-kselftest, linux-modules, linux-perf-users, lkml, rust-for-linux, sched-ext
Subsystem:
bpf [general] (safe dynamic programs and tools), kernel build + files below scripts/ (unless maintained elsewhere), module support, netfilter, networking [general], networking [ipsec], the rest, tracing · Maintainers:
Alexei Starovoitov, Daniel Borkmann, Andrii Nakryiko, Eduard Zingerman, Kumar Kartikeya Dwivedi, Nathan Chancellor, Nicolas Schier, Luis Chamberlain, Petr Pavlu, Daniel Gomez, Sami Tolvanen, Pablo Neira Ayuso, Florian Westphal, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Steffen Klassert, Herbert Xu, Linus Torvalds, Steven Rostedt, Masami Hiramatsu
Revision v4 of 3 in this series.
Revisions (3)
- v2 [diff vs current]
- v3 [diff vs current]
- v4 current
The next patch makes CONFIG_DEBUG_INFO_BTF a tristate. With =m, Kconfig defines CONFIG_DEBUG_INFO_BTF_MODULE instead of CONFIG_DEBUG_INFO_BTF, so every check that must hold for both =y and =m has to be written for it: - #ifdef CONFIG_DEBUG_INFO_BTF becomes #if IS_ENABLED(...) where the generated BTF and its id tables must be the same for =y and =m: the .BTF_ids tables (btf_ids.h), the BTF type tags (compiler_types.h), and the tracepoint and syscall BTF ids (trace_events.h, trace_syscalls.c). Leaving them would silently produce empty id sets with =m. - obj-$(CONFIG_DEBUG_INFO_BTF) and include-$(CONFIG_DEBUG_INFO_BTF) become $(subst m,y,...) where the object is built into the kernel regardless: sysfs_btf.o, the netfilter and xfrm kfunc objects, and scripts/Makefile.btf. Otherwise =m would try to build them as modules (xfrm_state_bpf.o fails modpost for lack of MODULE_LICENSE) or skip the BTF generation flags. - "depends on !DEBUG_INFO_BTF" becomes "depends on DEBUG_INFO_BTF=n" for RUST and GENDWARFKSYMS: with =m the BTF is generated as with =y, so the pahole restrictions they express still apply, but !m is m, which a bool option takes as y. No functional change: CONFIG_DEBUG_INFO_BTF is still a bool, for which IS_ENABLED() and #ifdef agree, $(subst m,y,y) is y and "=n" is "!". Signed-off-by: Jay Wang <redacted> --- Makefile | 3 ++- include/linux/btf_ids.h | 2 +- include/linux/compiler_types.h | 2 +- include/trace/trace_events.h | 2 +- init/Kconfig | 2 +- kernel/bpf/Makefile | 2 +- kernel/module/Kconfig | 2 +- kernel/trace/trace_syscalls.c | 6 +++--- net/netfilter/Makefile | 6 +++--- net/xfrm/Makefile | 4 ++-- 10 files changed, 16 insertions(+), 15 deletions(-)
diff --git a/Makefile b/Makefile
index 751a08643bf8..f561516e1735 100644
--- a/Makefile
+++ b/Makefile@@ -1208,7 +1208,8 @@ endif # include additional Makefiles when needed include-y := scripts/Makefile.warn include-$(CONFIG_DEBUG_INFO) += scripts/Makefile.debug -include-$(CONFIG_DEBUG_INFO_BTF)+= scripts/Makefile.btf +# CONFIG_DEBUG_INFO_BTF is a tristate; BTF is generated for both y and m +include-$(subst m,y,$(CONFIG_DEBUG_INFO_BTF)) += scripts/Makefile.btf include-$(CONFIG_KASAN) += scripts/Makefile.kasan include-$(CONFIG_KCSAN) += scripts/Makefile.kcsan include-$(CONFIG_KMSAN) += scripts/Makefile.kmsan
diff --git a/include/linux/btf_ids.h b/include/linux/btf_ids.h
index 8b5a9ee92513..c665afff100e 100644
--- a/include/linux/btf_ids.h
+++ b/include/linux/btf_ids.h@@ -22,7 +22,7 @@ struct btf_id_set8 { } pairs[]; }; -#ifdef CONFIG_DEBUG_INFO_BTF +#if IS_ENABLED(CONFIG_DEBUG_INFO_BTF) #include <linux/compiler.h> /* for __PASTE */ #include <linux/compiler_attributes.h> /* for __maybe_unused */
diff --git a/include/linux/compiler_types.h b/include/linux/compiler_types.h
index c5921f139007..a90a99849cee 100644
--- a/include/linux/compiler_types.h
+++ b/include/linux/compiler_types.h@@ -34,7 +34,7 @@ * Skipped when running bindgen due to a libclang issue; * see https://github.com/rust-lang/rust-bindgen/issues/2244. */ -#if defined(CONFIG_DEBUG_INFO_BTF) && defined(CONFIG_PAHOLE_HAS_BTF_TAG) && \ +#if IS_ENABLED(CONFIG_DEBUG_INFO_BTF) && defined(CONFIG_PAHOLE_HAS_BTF_TAG) && \ __has_attribute(btf_type_tag) && !defined(__BINDGEN__) # define BTF_TYPE_TAG(value) __attribute__((btf_type_tag(#value))) #else
diff --git a/include/trace/trace_events.h b/include/trace/trace_events.h
index 93011f800d0f..2a0098929771 100644
--- a/include/trace/trace_events.h
+++ b/include/trace/trace_events.h@@ -398,7 +398,7 @@ static inline notrace int trace_event_get_offsets_##call( \ #define _TRACE_PERF_INIT(call) #endif /* CONFIG_PERF_EVENTS */ -#if defined(CONFIG_BPF_EVENTS) && defined(CONFIG_DEBUG_INFO_BTF) +#if defined(CONFIG_BPF_EVENTS) && IS_ENABLED(CONFIG_DEBUG_INFO_BTF) /* * Per-template BTF id list, populated at link time by resolve_btfids: * [0] FUNC __bpf_trace_<call> (the BPF dispatcher)
diff --git a/init/Kconfig b/init/Kconfig
index 8583d9f06c52..9f9562f813c5 100644
--- a/init/Kconfig
+++ b/init/Kconfig@@ -2257,7 +2257,7 @@ config RUST depends on !MODVERSIONS || GENDWARFKSYMS depends on !GCC_PLUGIN_RANDSTRUCT depends on !RANDSTRUCT - depends on !DEBUG_INFO_BTF || (PAHOLE_HAS_LANG_EXCLUDE && !LTO) + depends on DEBUG_INFO_BTF=n || (PAHOLE_HAS_LANG_EXCLUDE && !LTO) depends on !CFI || HAVE_CFI_ICALL_NORMALIZE_INTEGERS_RUSTC select CFI_ICALL_NORMALIZE_INTEGERS if CFI depends on !KASAN || CC_IS_CLANG
diff --git a/kernel/bpf/Makefile b/kernel/bpf/Makefile
index c1f9b0d3468d..0b7db88f1bed 100644
--- a/kernel/bpf/Makefile
+++ b/kernel/bpf/Makefile@@ -41,7 +41,7 @@ ifeq ($(CONFIG_INET),y) obj-$(CONFIG_BPF_SYSCALL) += reuseport_array.o endif ifeq ($(CONFIG_SYSFS),y) -obj-$(CONFIG_DEBUG_INFO_BTF) += sysfs_btf.o +obj-$(subst m,y,$(CONFIG_DEBUG_INFO_BTF)) += sysfs_btf.o endif ifeq ($(CONFIG_BPF_JIT),y) obj-$(CONFIG_BPF_SYSCALL) += bpf_struct_ops.o
diff --git a/kernel/module/Kconfig b/kernel/module/Kconfig
index 43b1bb01fd27..da49cb984b0d 100644
--- a/kernel/module/Kconfig
+++ b/kernel/module/Kconfig@@ -197,7 +197,7 @@ config GENDWARFKSYMS # X86, requires pahole before commit 47dcb534e253 ("btf_encoder: Stop # indexing symbols for VARs") or after commit 9810758003ce ("btf_encoder: # Verify 0 address DWARF variables are in ELF section"). - depends on !X86 || !DEBUG_INFO_BTF || PAHOLE_VERSION < 128 || PAHOLE_VERSION > 129 + depends on !X86 || DEBUG_INFO_BTF=n || PAHOLE_VERSION < 128 || PAHOLE_VERSION > 129 help Calculate symbol versions from DWARF debugging information using gendwarfksyms. Requires DEBUG_INFO to be enabled.
diff --git a/kernel/trace/trace_syscalls.c b/kernel/trace/trace_syscalls.c
index e35744049e3f..7a0d59c308c2 100644
--- a/kernel/trace/trace_syscalls.c
+++ b/kernel/trace/trace_syscalls.c@@ -1304,7 +1304,7 @@ struct trace_event_functions exit_syscall_print_funcs = { .trace = print_syscall_exit, }; -#if defined(CONFIG_BPF_EVENTS) && defined(CONFIG_DEBUG_INFO_BTF) +#if defined(CONFIG_BPF_EVENTS) && IS_ENABLED(CONFIG_DEBUG_INFO_BTF) /* BTF id lists for the shared sys_enter/sys_exit dispatcher tracepoints. */ BTF_ID_LIST(syscall_enter_btf_ids) BTF_ID(func, __bpf_trace_sys_enter)
@@ -1321,7 +1321,7 @@ struct trace_event_class __refdata event_class_syscall_enter = { .fields_array = syscall_enter_fields_array, .get_fields = syscall_get_enter_fields, .raw_init = init_syscall_trace, -#if defined(CONFIG_BPF_EVENTS) && defined(CONFIG_DEBUG_INFO_BTF) +#if defined(CONFIG_BPF_EVENTS) && IS_ENABLED(CONFIG_DEBUG_INFO_BTF) .btf_ids = syscall_enter_btf_ids, #endif };
@@ -1336,7 +1336,7 @@ struct trace_event_class __refdata event_class_syscall_exit = { }, .fields = LIST_HEAD_INIT(event_class_syscall_exit.fields), .raw_init = init_syscall_trace, -#if defined(CONFIG_BPF_EVENTS) && defined(CONFIG_DEBUG_INFO_BTF) +#if defined(CONFIG_BPF_EVENTS) && IS_ENABLED(CONFIG_DEBUG_INFO_BTF) .btf_ids = syscall_exit_btf_ids, #endif };
diff --git a/net/netfilter/Makefile b/net/netfilter/Makefile
index 6bf74d488a29..a2c7f00794d2 100644
--- a/net/netfilter/Makefile
+++ b/net/netfilter/Makefile@@ -18,7 +18,7 @@ nf_conntrack-$(CONFIG_NF_CT_PROTO_GRE) += nf_conntrack_proto_gre.o ifeq ($(CONFIG_NF_CONNTRACK),m) nf_conntrack-$(CONFIG_DEBUG_INFO_BTF_MODULES) += nf_conntrack_bpf.o else ifeq ($(CONFIG_NF_CONNTRACK),y) -nf_conntrack-$(CONFIG_DEBUG_INFO_BTF) += nf_conntrack_bpf.o +nf_conntrack-$(subst m,y,$(CONFIG_DEBUG_INFO_BTF)) += nf_conntrack_bpf.o endif obj-$(CONFIG_NETFILTER) = netfilter.o
@@ -65,7 +65,7 @@ nf_nat-$(CONFIG_NF_NAT_OVS) += nf_nat_ovs.o ifeq ($(CONFIG_NF_NAT),m) nf_nat-$(CONFIG_DEBUG_INFO_BTF_MODULES) += nf_nat_bpf.o else ifeq ($(CONFIG_NF_NAT),y) -nf_nat-$(CONFIG_DEBUG_INFO_BTF) += nf_nat_bpf.o +nf_nat-$(subst m,y,$(CONFIG_DEBUG_INFO_BTF)) += nf_nat_bpf.o endif # NAT helpers
@@ -147,7 +147,7 @@ nf_flow_table-$(CONFIG_NF_FLOW_TABLE_PROCFS) += nf_flow_table_procfs.o ifeq ($(CONFIG_NF_FLOW_TABLE),m) nf_flow_table-$(CONFIG_DEBUG_INFO_BTF_MODULES) += nf_flow_table_bpf.o else ifeq ($(CONFIG_NF_FLOW_TABLE),y) -nf_flow_table-$(CONFIG_DEBUG_INFO_BTF) += nf_flow_table_bpf.o +nf_flow_table-$(subst m,y,$(CONFIG_DEBUG_INFO_BTF)) += nf_flow_table_bpf.o endif obj-$(CONFIG_NF_FLOW_TABLE_INET) += nf_flow_table_inet.o
diff --git a/net/xfrm/Makefile b/net/xfrm/Makefile
index 5a1787587cb3..b7f6e5046a0e 100644
--- a/net/xfrm/Makefile
+++ b/net/xfrm/Makefile@@ -8,7 +8,7 @@ xfrm_interface-$(CONFIG_XFRM_INTERFACE) += xfrm_interface_core.o ifeq ($(CONFIG_XFRM_INTERFACE),m) xfrm_interface-$(CONFIG_DEBUG_INFO_BTF_MODULES) += xfrm_interface_bpf.o else ifeq ($(CONFIG_XFRM_INTERFACE),y) -xfrm_interface-$(CONFIG_DEBUG_INFO_BTF) += xfrm_interface_bpf.o +xfrm_interface-$(subst m,y,$(CONFIG_DEBUG_INFO_BTF)) += xfrm_interface_bpf.o endif obj-$(CONFIG_XFRM) := xfrm_policy.o xfrm_state.o xfrm_hash.o \
@@ -23,4 +23,4 @@ obj-$(CONFIG_XFRM_IPCOMP) += xfrm_ipcomp.o obj-$(CONFIG_XFRM_INTERFACE) += xfrm_interface.o obj-$(CONFIG_XFRM_IPTFS) += xfrm_iptfs.o obj-$(CONFIG_XFRM_ESPINTCP) += espintcp.o -obj-$(CONFIG_DEBUG_INFO_BTF) += xfrm_state_bpf.o +obj-$(subst m,y,$(CONFIG_DEBUG_INFO_BTF)) += xfrm_state_bpf.o
--
2.47.3