linux-kernel - [tip: core/objtool] x86/kexec: Make relocate_kernel

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Date:   Thu, 26 Mar 2020 10:08:37 -0000
From:   "tip-bot2 for Peter Zijlstra" <tip-bot2@...utronix.de>
To:     linux-tip-commits@...r.kernel.org
Cc:     Josh Poimboeuf <jpoimboe@...hat.com>,
        "Peter Zijlstra (Intel)" <peterz@...radead.org>,
        Miroslav Benes <mbenes@...e.cz>, x86 <x86@...nel.org>,
        LKML <linux-kernel@...r.kernel.org>
Subject: [tip: core/objtool] x86/kexec: Make relocate_kernel_64.S objtool clean

The following commit has been merged into the core/objtool branch of tip:

Commit-ID:     36cc552055a5f95bab479533b4ebbad6a6cea0e1
Gitweb:        https://git.kernel.org/tip/36cc552055a5f95bab479533b4ebbad6a6cea0e1
Author:        Peter Zijlstra <peterz@...radead.org>
AuthorDate:    Tue, 24 Mar 2020 15:35:42 +01:00
Committer:     Peter Zijlstra <peterz@...radead.org>
CommitterDate: Wed, 25 Mar 2020 18:28:28 +01:00

x86/kexec: Make relocate_kernel_64.S objtool clean

Having fixed the biggest objtool issue in this file; fix up the rest
and remove the exception.

Suggested-by: Josh Poimboeuf <jpoimboe@...hat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@...radead.org>
Reviewed-by: Miroslav Benes <mbenes@...e.cz>
Acked-by: Josh Poimboeuf <jpoimboe@...hat.com>
Link: https://lkml.kernel.org/r/20200324160924.202621656@infradead.org
---
 arch/x86/kernel/Makefile             | 1 -
 arch/x86/kernel/relocate_kernel_64.S | 7 +++++++
 2 files changed, 7 insertions(+), 1 deletion(-)

diff --git a/arch/x86/kernel/Makefile b/arch/x86/kernel/Makefile
index 9b294c1..8be5926 100644
--- a/arch/x86/kernel/Makefile
+++ b/arch/x86/kernel/Makefile
@@ -28,7 +28,6 @@ KASAN_SANITIZE_dumpstack_$(BITS).o			:= n
 KASAN_SANITIZE_stacktrace.o				:= n
 KASAN_SANITIZE_paravirt.o				:= n
 
-OBJECT_FILES_NON_STANDARD_relocate_kernel_$(BITS).o	:= y
 OBJECT_FILES_NON_STANDARD_test_nx.o			:= y
 OBJECT_FILES_NON_STANDARD_paravirt_patch.o		:= y
 
diff --git a/arch/x86/kernel/relocate_kernel_64.S b/arch/x86/kernel/relocate_kernel_64.S
index cc5c8b9..a4d9a26 100644
--- a/arch/x86/kernel/relocate_kernel_64.S
+++ b/arch/x86/kernel/relocate_kernel_64.S
@@ -9,6 +9,8 @@
 #include <asm/kexec.h>
 #include <asm/processor-flags.h>
 #include <asm/pgtable_types.h>
+#include <asm/nospec-branch.h>
+#include <asm/unwind_hints.h>
 
 /*
  * Must be relocatable PIC code callable as a C function
@@ -39,6 +41,7 @@
 	.align PAGE_SIZE
 	.code64
 SYM_CODE_START_NOALIGN(relocate_kernel)
+	UNWIND_HINT_EMPTY
 	/*
 	 * %rdi indirection_page
 	 * %rsi page_list
@@ -105,6 +108,7 @@ SYM_CODE_START_NOALIGN(relocate_kernel)
 SYM_CODE_END(relocate_kernel)
 
 SYM_CODE_START_LOCAL_NOALIGN(identity_mapped)
+	UNWIND_HINT_EMPTY
 	/* set return address to 0 if not preserving context */
 	pushq	$0
 	/* store the start address on the stack */
@@ -192,6 +196,7 @@ SYM_CODE_START_LOCAL_NOALIGN(identity_mapped)
 1:
 	popq	%rdx
 	leaq	PAGE_SIZE(%r10), %rsp
+	ANNOTATE_RETPOLINE_SAFE
 	call	*%rdx
 
 	/* get the re-entry point of the peer system */
@@ -209,6 +214,7 @@ SYM_CODE_START_LOCAL_NOALIGN(identity_mapped)
 SYM_CODE_END(identity_mapped)
 
 SYM_CODE_START_LOCAL_NOALIGN(virtual_mapped)
+	UNWIND_HINT_EMPTY
 	movq	RSP(%r8), %rsp
 	movq	CR4(%r8), %rax
 	movq	%rax, %cr4
@@ -230,6 +236,7 @@ SYM_CODE_END(virtual_mapped)
 
 	/* Do the copies */
 SYM_CODE_START_LOCAL_NOALIGN(swap_pages)
+	UNWIND_HINT_EMPTY
 	movq	%rdi, %rcx 	/* Put the page_list in %rcx */
 	xorl	%edi, %edi
 	xorl	%esi, %esi