Commit-ID: 10b87bc9f630a38a7f0c1e7cf13ff23fea1692ec
Gitweb: https://git.kernel.org/tip/10b87bc9f630a38a7f0c1e7cf13ff23fea1692ec
Author: Masahiro Yamada <yamada.masah...@socionext.com>
AuthorDate: Wed, 5 Dec 2018 15:27:19 +0900
Committer: Ingo Molnar <mi...@kernel.org>
CommitDate: Wed, 5 Dec 2018 08:42:09 +0100
x86/build: Fix compiler support check for CONFIG_RETPOLINE
It is troublesome to add a diagnostic like this to the Makefile
parse stage because the top-level Makefile could be parsed with
a stale include/config/auto.conf.
Once you are hit by the error about non-retpoline compiler, the
compilation still breaks even after disabling CONFIG_RETPOLINE.
The easiest fix is to move this check to the "archprepare" like
this commit did:
829fe4aa9ac1 ("x86: Allow generating user-space headers without a compiler")
Reported-by: Meelis Roos <mr...@linux.ee>
Signed-off-by: Masahiro Yamada <yamada.masah...@socionext.com>
Acked-by: Zhenzhong Duan <zhenzhong.d...@oracle.com>
Cc: Borislav Petkov <b...@alien8.de>
Cc: Linus Torvalds <torva...@linux-foundation.org>
Cc: Peter Zijlstra <pet...@infradead.org>
Cc: Thomas Gleixner <t...@linutronix.de>
Cc: Zhenzhong Duan <zhenzhong.d...@oracle.com>
Fixes: 4cd24de3a098 ("x86/retpoline: Make CONFIG_RETPOLINE depend on compiler
support")
Link:
http://lkml.kernel.org/r/1543991239-18476-1-git-send-email-yamada.masah...@socionext.com
Link: https://lkml.org/lkml/2018/12/4/206
Signed-off-by: Ingo Molnar <mi...@kernel.org>
---
arch/x86/Makefile | 10 +++++++---
1 file changed, 7 insertions(+), 3 deletions(-)
diff --git a/arch/x86/Makefile b/arch/x86/Makefile
index f5d7f4134524..75ef499a66e2 100644
--- a/arch/x86/Makefile
+++ b/arch/x86/Makefile
@@ -220,9 +220,6 @@ KBUILD_CFLAGS += -fno-asynchronous-unwind-tables
# Avoid indirect branches in kernel to deal with Spectre
ifdef CONFIG_RETPOLINE
-ifeq ($(RETPOLINE_CFLAGS),)
- $(error You are building kernel with non-retpoline compiler, please update
your compiler.)
-endif
KBUILD_CFLAGS += $(RETPOLINE_CFLAGS)
endif
@@ -307,6 +304,13 @@ ifndef CC_HAVE_ASM_GOTO
@echo Compiler lacks asm-goto support.
@exit 1
endif
+ifdef CONFIG_RETPOLINE
+ifeq ($(RETPOLINE_CFLAGS),)
+ @echo "You are building kernel with non-retpoline compiler." >&2
+ @echo "Please update your compiler." >&2
+ @false
+endif
+endif
archclean:
$(Q)rm -rf $(objtree)/arch/i386
