From: Shivang Upadhyay <shivangu@linux.ibm.com>
To: linux-kbuild@vger.kernel.org, linux-kernel@vger.kernel.org,
linuxppc-dev@lists.ozlabs.org
Cc: sv@linux.ibm.com, alexandre.chartre@oracle.com,
alexghiti@rivosinc.com, aliceryhl@google.com, ardb@kernel.org,
bp@alien8.de, chleroy@kernel.org, elver@google.com,
ihor.solodrai@linux.dev, jpoimboe@kernel.org, kees@kernel.org,
legion@kernel.org, lossin@kernel.org, maddy@linux.ibm.com,
masahiroy@kernel.org, mpe@ellerman.id.au, nathan@kernel.org,
npiggin@gmail.com, nsc@kernel.org, ojeda@kernel.org,
peterz@infradead.org, pmladek@suse.com, rostedt@goodmis.org,
tamird@kernel.org, thomas.weissschuh@linutronix.de,
thuth@redhat.com, yuxuan.zuo@outlook.com,
sourabhjain@linux.ibm.com,
Shivang Upadhyay <shivangu@linux.ibm.com>
Subject: [PATCH v2 5/6] kbuild: Add objtool integration for PowerPC feature fixups
Date: Tue, 29 Sep 2026 11:21:36 +0530 [thread overview]
Message-ID: <20260929055138.43489-6-shivangu@linux.ibm.com> (raw)
In-Reply-To: <20260929055138.43489-1-shivangu@linux.ibm.com>
From: Sathvika Vasireddy <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
Signed-off-by: Shivang Upadhyay <shivangu@linux.ibm.com>
---
Makefile | 7 +++++++
scripts/Makefile.lib | 4 ++--
scripts/Makefile.vmlinux | 3 ++-
3 files changed, 11 insertions(+), 3 deletions(-)
diff --git a/Makefile b/Makefile
index 6b8b812f23b9..363cad32fb26 100644
--- a/Makefile
+++ b/Makefile
@@ -1566,6 +1566,13 @@ 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 0a4fdd8bd975..efcedeb207b7 100644
--- a/scripts/Makefile.lib
+++ b/scripts/Makefile.lib
@@ -182,10 +182,10 @@ 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
--
2.54.0
next prev parent reply other threads:[~2026-09-29 5:53 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-09-29 5:51 [PATCH v2 0/6] objtool: Fixup alternate feature relative addresses Shivang Upadhyay
2026-09-29 5:51 ` [PATCH v2 1/6] objtool/powerpc: Add build-time fixup of alternate feature branch targets Shivang Upadhyay
2026-09-29 5:51 ` [PATCH v2 2/6] objtool: Set ELF_F_LAYOUT flag to preserve vmlinux segment layout Shivang Upadhyay
2026-09-30 9:48 ` Peter Zijlstra
2026-09-29 5:51 ` [PATCH v2 3/6] objtool: Fix "can't find starting instruction" warnings on vmlinux Shivang Upadhyay
2026-09-29 14:12 ` Peter Zijlstra
2026-09-29 14:24 ` Peter Zijlstra
2026-09-29 5:51 ` [PATCH v2 4/6] objtool/powerpc: Skip jump destination analysis and unnanotated intra-function call warnings for --ftr-fixup Shivang Upadhyay
2026-09-29 14:25 ` Peter Zijlstra
2026-09-30 6:13 ` Shivang Upadhyay
2026-09-30 9:44 ` Peter Zijlstra
2026-10-06 6:14 ` Shivang Upadhyay
2026-09-29 5:51 ` Shivang Upadhyay [this message]
2026-09-29 5:51 ` [PATCH v2 6/6] powerpc: Enable build-time feature fixup processing by default Shivang Upadhyay
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