27 lines
971 B
Diff
27 lines
971 B
Diff
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From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
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From: Arjan van de Ven <arjan@linux.intel.com>
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Date: Thu, 8 Feb 2018 16:49:38 +0000
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Subject: [PATCH] zero extra registers
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This for Zero used caller-saved general registers upon function return.
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---
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arch/x86/Makefile | 2 +-
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1 file changed, 1 insertion(+), 1 deletion(-)
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diff --git a/arch/x86/Makefile b/arch/x86/Makefile
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index 94df0868804b..083a97af538c 100644
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--- a/arch/x86/Makefile
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+++ b/arch/x86/Makefile
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@@ -216,7 +216,7 @@ KBUILD_CFLAGS += -fno-asynchronous-unwind-tables
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# Avoid indirect branches in kernel to deal with Spectre
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ifdef CONFIG_RETPOLINE
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- KBUILD_CFLAGS += $(RETPOLINE_CFLAGS)
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+ KBUILD_CFLAGS += $(RETPOLINE_CFLAGS) -mzero-caller-saved-regs=used
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# Additionally, avoid generating expensive indirect jumps which
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# are subject to retpolines for small number of switch cases.
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# clang turns off jump table generation by default when under
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--
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https://clearlinux.org
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