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authorMark Rutland <mark.rutland@arm.com>2021-06-18 16:11:22 +0100
committerWill Deacon <will@kernel.org>2021-06-21 11:58:03 +0100
commit69bb0585ebb0c48c93fc55fc27afbfc06adef2fd (patch)
tree7afd47d8cd20c9dae154f78fd57093182f8eeacd /arch/arm64/include/asm/insn-def.h
parent3e00e39d9dad48360ebd518726ebf81da1b84c10 (diff)
arm64: insn: avoid circular include dependency
Nathan reports that when building with CONFIG_LTO_CLANG_THIN=y, the build fails due to BUILD_BUG_ON() not being defined before its uss in <asm/insn.h>. The problem is that with LTO, we patch READ_ONCE(), and <asm/rwonce.h> includes <asm/insn.h>, creating a circular include chain: <linux/build_bug.h> <linux/compiler.h> <asm/rwonce.h> <asm/alternative-macros.h> <asm/insn.h> <linux/build-bug.h> ... and so when <asm/insn.h> includes <linux/build_bug.h>, none of the BUILD_BUG* definitions have happened yet. To avoid this, let's move AARCH64_INSN_SIZE into a header without any dependencies, such that it can always be safely included. At the same time, avoid including <asm/alternative.h> in <asm/insn.h>, which should no longer be necessary (and doesn't make sense when insn.h is consumed by userspace). Reported-by: Nathan Chancellor <nathan@kernel.org> Signed-off-by: Mark Rutland <mark.rutland@arm.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will@kernel.org> Link: https://lore.kernel.org/r/20210621080830.GA37068@C02TD0UTHF1T.local Fixes: 3e00e39d9dad ("arm64: insn: move AARCH64_INSN_SIZE into <asm/insn.h>") Signed-off-by: Will Deacon <will@kernel.org>
Diffstat (limited to 'arch/arm64/include/asm/insn-def.h')
-rw-r--r--arch/arm64/include/asm/insn-def.h9
1 files changed, 9 insertions, 0 deletions
diff --git a/arch/arm64/include/asm/insn-def.h b/arch/arm64/include/asm/insn-def.h
new file mode 100644
index 000000000000..2c075f615c6a
--- /dev/null
+++ b/arch/arm64/include/asm/insn-def.h
@@ -0,0 +1,9 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+
+#ifndef __ASM_INSN_DEF_H
+#define __ASM_INSN_DEF_H
+
+/* A64 instructions are always 32 bits. */
+#define AARCH64_INSN_SIZE 4
+
+#endif /* __ASM_INSN_DEF_H */