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From:   Josh Poimboeuf <jpoimboe@redhat.com>
To:     x86@kernel.org
Cc:     Peter Zijlstra <peterz@infradead.org>,
        linux-kernel@vger.kernel.org, Miroslav Benes <mbenes@suse.cz>
Subject: [PATCH v2 01/25] objtool: Enable unreachable warnings for CLANG LTO
Date:   Mon, 18 Apr 2022 09:50:20 -0700
Message-Id: <7b12df54bceeb0761fe9fc8269ea0c00501214a9.1650300597.git.jpoimboe@redhat.com>
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References: <cover.1650300597.git.jpoimboe@redhat.com>
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With IBT support in, objtool is now fully capable of following vmlinux
code flow in LTO mode.  Start reporting unreachable warnings for Clang
LTO as well.

Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
---
 scripts/Makefile.build  | 2 +-
 scripts/link-vmlinux.sh | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/scripts/Makefile.build b/scripts/Makefile.build
index 9717e6f6fb31..33c1ed581522 100644
--- a/scripts/Makefile.build
+++ b/scripts/Makefile.build
@@ -231,7 +231,7 @@ objtool_args =								\
 	$(if $(part-of-module), --module)				\
 	$(if $(CONFIG_X86_KERNEL_IBT), --lto --ibt)			\
 	$(if $(CONFIG_FRAME_POINTER),, --no-fp)				\
-	$(if $(CONFIG_GCOV_KERNEL)$(CONFIG_LTO_CLANG), --no-unreachable)\
+	$(if $(CONFIG_GCOV_KERNEL), --no-unreachable)			\
 	$(if $(CONFIG_RETPOLINE), --retpoline)				\
 	$(if $(CONFIG_X86_SMAP), --uaccess)				\
 	$(if $(CONFIG_FTRACE_MCOUNT_USE_OBJTOOL), --mcount)		\
diff --git a/scripts/link-vmlinux.sh b/scripts/link-vmlinux.sh
index 20f44504a644..9361a1ef02c9 100755
--- a/scripts/link-vmlinux.sh
+++ b/scripts/link-vmlinux.sh
@@ -140,7 +140,7 @@ objtool_link()
 		if ! is_enabled CONFIG_FRAME_POINTER; then
 			objtoolopt="${objtoolopt} --no-fp"
 		fi
-		if is_enabled CONFIG_GCOV_KERNEL || is_enabled CONFIG_LTO_CLANG; then
+		if is_enabled CONFIG_GCOV_KERNEL; then
 			objtoolopt="${objtoolopt} --no-unreachable"
 		fi
 		if is_enabled CONFIG_RETPOLINE; then
-- 
2.34.1