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authorAlexander Lobakin <alobakin@pm.me>2021-01-21 18:45:55 +0000
committerKees Cook <keescook@chromium.org>2021-02-17 10:10:37 -0800
commit2b8689520520175075ca97bc4eaf51ff3f7253aa (patch)
tree8aca8ffa3b7dc1b7b46828b73e6232fbf43eba0c
parent112b6a8e038d793d016e330f53acb9383ac504b3 (diff)
kbuild: prevent CC_FLAGS_LTO self-bloating on recursive rebuilds
CC_FLAGS_LTO gets initialized only via +=, never with := or =. When building with CONFIG_TRIM_UNUSED_KSYMS, Kbuild may perform several kernel rebuilds to satisfy symbol dependencies. In this case, value of CC_FLAGS_LTO is concatenated each time, which triggers a full rebuild. Initialize it with := to fix this. Fixes: dc5723b02e52 ("kbuild: add support for Clang LTO") Signed-off-by: Alexander Lobakin <alobakin@pm.me> Signed-off-by: Kees Cook <keescook@chromium.org> Link: https://lore.kernel.org/r/20210121184544.659998-1-alobakin@pm.me
-rw-r--r--Makefile4
1 files changed, 2 insertions, 2 deletions
diff --git a/Makefile b/Makefile
index 668909e7a460..2233951666f7 100644
--- a/Makefile
+++ b/Makefile
@@ -895,10 +895,10 @@ endif
ifdef CONFIG_LTO_CLANG
ifdef CONFIG_LTO_CLANG_THIN
-CC_FLAGS_LTO += -flto=thin -fsplit-lto-unit
+CC_FLAGS_LTO := -flto=thin -fsplit-lto-unit
KBUILD_LDFLAGS += --thinlto-cache-dir=$(extmod-prefix).thinlto-cache
else
-CC_FLAGS_LTO += -flto
+CC_FLAGS_LTO := -flto
endif
CC_FLAGS_LTO += -fvisibility=hidden