From: Sathvika Vasireddy <sv@linux.ibm.com>
To: nathan@kernel.org, nsc@kernel.org, maddy@linux.ibm.com,
mpe@ellerman.id.au, npiggin@gmail.com, chleroy@kernel.org,
jpoimboe@kernel.org, peterz@infradead.org, ojeda@kernel.org,
masahiroy@kernel.org, lossin@kernel.org, tamird@kernel.org,
thomas.weissschuh@linutronix.de, rostedt@goodmis.org,
ihor.solodrai@linux.dev, thuth@redhat.com, pmladek@suse.com,
aliceryhl@google.com, elver@google.com, kees@kernel.org,
legion@kernel.org, ardb@kernel.org, yuxuan.zuo@outlook.com,
alexghiti@rivosinc.com, alexandre.chartre@oracle.com,
bp@alien8.de, linux-kbuild@vger.kernel.org,
linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org,
sv@linux.ibm.com
Subject: [PATCH v1 5/6] kbuild: Add objtool integration for PowerPC feature fixups
Date: Tue, 5 May 2026 14:16:27 +0530 [thread overview]
Message-ID: <20260505084628.17940-6-sv@linux.ibm.com> (raw)
In-Reply-To: <20260505084628.17940-1-sv@linux.ibm.com>
Add build system support for PowerPC feature fixup processing:
- Add HAVE_OBJTOOL_FTR_FIXUP config option for architectures that support
build-time feature fixup processing
- Integrate objtool feature fixup processing into vmlinux build
Suggested-by: Masahiro Yamada <masahiroy@kernel.org>
Signed-off-by: Sathvika Vasireddy <sv@linux.ibm.com>
Acked-by: Nicolas Schier <nsc@kernel.org> # kbuild
---
Makefile | 7 +++++++
scripts/Makefile.lib | 4 ++--
scripts/Makefile.vmlinux | 3 ++-
3 files changed, 11 insertions(+), 3 deletions(-)
diff --git a/Makefile b/Makefile
index 6b1d9fb1a6b4..f9a990036f3f 100644
--- a/Makefile
+++ b/Makefile
@@ -1478,6 +1478,13 @@ ifdef CONFIG_OBJTOOL
prepare: tools/objtool
endif
+# CONFIG_OBJTOOL and CONFIG_HAVE_OBJTOOL_FTR_FIXUP are unrelated, separate
+# options. It was integrated in objtool in order to borrow the elf parser,
+# but this is different from how the other objtool commands are used.
+ifdef CONFIG_HAVE_OBJTOOL_FTR_FIXUP
+prepare: tools/objtool
+endif
+
ifdef CONFIG_BPF
ifdef CONFIG_DEBUG_INFO_BTF
prepare: tools/bpf/resolve_btfids
diff --git a/scripts/Makefile.lib b/scripts/Makefile.lib
index 0718e39cedda..fa72619e5bb0 100644
--- a/scripts/Makefile.lib
+++ b/scripts/Makefile.lib
@@ -179,10 +179,10 @@ cpp_flags = -Wp,-MMD,$(depfile) $(NOSTDINC_FLAGS) $(LINUXINCLUDE) \
ld_flags = $(KBUILD_LDFLAGS) $(ldflags-y) $(LDFLAGS_$(@F))
-ifdef CONFIG_OBJTOOL
-
objtool := $(objtree)/tools/objtool/objtool
+ifdef CONFIG_OBJTOOL
+
objtool-args-$(CONFIG_HAVE_JUMP_LABEL_HACK) += --hacks=jump_label
objtool-args-$(CONFIG_HAVE_NOINSTR_HACK) += --hacks=noinstr
objtool-args-$(CONFIG_MITIGATION_CALL_DEPTH_TRACKING) += --hacks=skylake
diff --git a/scripts/Makefile.vmlinux b/scripts/Makefile.vmlinux
index fcae1e432d9a..a1bef0638ecb 100644
--- a/scripts/Makefile.vmlinux
+++ b/scripts/Makefile.vmlinux
@@ -65,7 +65,8 @@ ARCH_POSTLINK := $(wildcard $(srctree)/arch/$(SRCARCH)/Makefile.postlink)
# Final link of vmlinux with optional arch pass after final link
cmd_link_vmlinux = \
$< "$(LD)" "$(KBUILD_LDFLAGS)" "$(LDFLAGS_vmlinux)" "$@"; \
- $(if $(ARCH_POSTLINK), $(MAKE) -f $(ARCH_POSTLINK) $@, true)
+ $(if $(ARCH_POSTLINK), $(MAKE) -f $(ARCH_POSTLINK) $@, true); \
+ $(if $(CONFIG_HAVE_OBJTOOL_FTR_FIXUP), $(objtool) --ftr-fixup --link $@, true)
targets += vmlinux.unstripped .vmlinux.export.o
vmlinux.unstripped: scripts/link-vmlinux.sh vmlinux.o .vmlinux.export.o $(KBUILD_LDS) FORCE
--
2.43.0
next prev parent reply other threads:[~2026-05-05 8:47 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-05-05 8:46 [PATCH v1 0/6] objtool: Fixup alternate feature relative addresses Sathvika Vasireddy
2026-05-05 8:46 ` [PATCH v1 1/6] objtool/powerpc: Add build-time fixup of alternate feature branch targets Sathvika Vasireddy
2026-05-05 14:45 ` Peter Zijlstra
2026-05-05 14:49 ` Peter Zijlstra
2026-05-05 15:48 ` Christophe Leroy (CS GROUP)
2026-05-05 15:56 ` Segher Boessenkool
2026-05-05 8:46 ` [PATCH v1 2/6] objtool: Set ELF_F_LAYOUT flag to preserve vmlinux segment layout Sathvika Vasireddy
2026-05-05 8:46 ` [PATCH v1 3/6] objtool: Fix "can't find starting instruction" warnings on vmlinux Sathvika Vasireddy
2026-05-05 8:46 ` [PATCH v1 4/6] objtool/powerpc: Skip jump destination analysis and unnanotated intra-function call warnings for --ftr-fixup Sathvika Vasireddy
2026-05-05 8:46 ` Sathvika Vasireddy [this message]
2026-05-05 8:46 ` [PATCH v1 6/6] powerpc: Enable build-time feature fixup processing by default Sathvika Vasireddy
2026-05-05 9:05 ` [PATCH v1 0/6] objtool: Fixup alternate feature relative addresses Christophe Leroy (CS GROUP)
2026-05-05 11:40 ` Peter Zijlstra
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