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From: Masahiro Yamada <>
To: Catalin Marinas <>,
	Will Deacon <>, (moderated for
Cc: Masahiro Yamada <>,,
Subject: [PATCH] arm64: move warning about toolchains to archprepare
Date: Sun,  1 Aug 2021 14:35:25 +0900	[thread overview]
Message-ID: <> (raw)

Commit 987fdfec2410 ("arm64: move --fix-cortex-a53-843419 linker test to
Kconfig") fixed the false-positive warning in the installation step.

Yet, there are some cases where this false-positive is shown. For example,
you can see it when you cross 987fdfec2410 during git-bisect.

  $ git checkout 987fdfec2410^
    [ snip ]
  $ make ARCH=arm64 CROSS_COMPILE=aarch64-linux-gnu- defconfig all
    [ snip ]
  $ git checkout v5.13
    [ snip]
  $ make ARCH=arm64 CROSS_COMPILE=aarch64-linux-gnu- defconfig all
    [ snip ]
  arch/arm64/Makefile:25: ld does not support --fix-cortex-a53-843419; kernel may be susceptible to erratum

In the stale include/config/auto.config, CONFIG_ARM64_ERRATUM_843419=y
is set without CONFIG_ARM64_LD_HAS_FIX_ERRATUM_843419, so the warning
is displayed while parsing the Makefiles.

Make will restart with the updated include/config/auto.config, hence
CONFIG_ARM64_LD_HAS_FIX_ERRATUM_843419 will be set eventually, but
this warning is a surprise for users.

Commit 25896d073d8a ("x86/build: Fix compiler support check for
CONFIG_RETPOLINE") addressed a similar issue.

Move $(warning ...) out of the parse stage of Makefiles.

The same applies to CONFIG_ARM64_USE_LSE_ATOMICS.

Signed-off-by: Masahiro Yamada <>

 arch/arm64/Makefile | 21 ++++++++++++---------
 1 file changed, 12 insertions(+), 9 deletions(-)

diff --git a/arch/arm64/Makefile b/arch/arm64/Makefile
index ded13230f901..8b0fd9d92390 100644
--- a/arch/arm64/Makefile
+++ b/arch/arm64/Makefile
@@ -21,19 +21,11 @@ LDFLAGS_vmlinux		+= -shared -Bsymbolic -z notext \
 ifeq ($(CONFIG_ARM64_ERRATUM_843419),y)
-  ifneq ($(CONFIG_ARM64_LD_HAS_FIX_ERRATUM_843419),y)
-$(warning ld does not support --fix-cortex-a53-843419; kernel may be susceptible to erratum)
-  else
+  ifeq ($(CONFIG_ARM64_LD_HAS_FIX_ERRATUM_843419),y)
 LDFLAGS_vmlinux	+= --fix-cortex-a53-843419
-  ifneq ($(CONFIG_ARM64_LSE_ATOMICS), y)
-$(warning LSE atomics not supported by binutils)
-  endif
 cc_has_k_constraint := $(call try-run,echo				\
 	'int main(void) {						\
 		asm volatile("and w0, w0, %w0" :: "K" (4294967295));	\
@@ -179,6 +171,17 @@ vdso_install:
 	$(Q)$(MAKE) $(build)=arch/arm64/tools kapi
+ifeq ($(CONFIG_ARM64_ERRATUM_843419),y)
+  ifneq ($(CONFIG_ARM64_LD_HAS_FIX_ERRATUM_843419),y)
+	@echo "warning: ld does not support --fix-cortex-a53-843419; kernel may be susceptible to erratum" >&2
+  endif
+  ifneq ($(CONFIG_ARM64_LSE_ATOMICS),y)
+	@echo "warning: LSE atomics not supported by binutils" >&2
+  endif

             reply	other threads:[~2021-08-01  5:37 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-08-01  5:35 Masahiro Yamada [this message]
2021-08-03 10:05 ` Will Deacon

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