From b5bc2231b8ad4387c9641f235ca0ad8cd300b6df Mon Sep 17 00:00:00 2001
From: Peter Zijlstra <peterz@infradead.org>
Date: Tue, 16 Jan 2018 10:24:06 +0100
Subject: objtool: Add retpoline validation

David requested a objtool validation pass for CONFIG_RETPOLINE=y enabled
builds, where it validates no unannotated indirect  jumps or calls are
left.

Add an additional .discard.retpoline_safe section to allow annotating
the few indirect sites that are required and safe.

Requested-by: David Woodhouse <dwmw2@infradead.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: David Woodhouse <dwmw@amazon.co.uk>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---
 scripts/Makefile.build | 4 ++++
 1 file changed, 4 insertions(+)

(limited to 'scripts')

diff --git a/scripts/Makefile.build b/scripts/Makefile.build
index 47cddf32aeba..53d862aee335 100644
--- a/scripts/Makefile.build
+++ b/scripts/Makefile.build
@@ -264,6 +264,10 @@ objtool_args += --no-unreachable
 else
 objtool_args += $(call cc-ifversion, -lt, 0405, --no-unreachable)
 endif
+ifdef CONFIG_RETPOLINE
+  objtool_args += --retpoline
+endif
+
 
 ifdef CONFIG_MODVERSIONS
 objtool_o = $(@D)/.tmp_$(@F)
-- 
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