2020-03-24 16:13:58

by Peter Zijlstra

[permalink] [raw]
Subject: [PATCH v3 05/26] 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 <[email protected]>
Signed-off-by: Peter Zijlstra (Intel) <[email protected]>
---
arch/x86/kernel/Makefile | 1 -
arch/x86/kernel/relocate_kernel_64.S | 7 +++++++
2 files changed, 7 insertions(+), 1 deletion(-)

--- a/arch/x86/kernel/Makefile
+++ b/arch/x86/kernel/Makefile
@@ -32,7 +32,6 @@ KASAN_SANITIZE_paravirt.o := n
# by several compilation units. To be safe, disable all instrumentation.
KCSAN_SANITIZE := 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

--- 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_ma
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_ma
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



2020-03-24 20:55:56

by Josh Poimboeuf

[permalink] [raw]
Subject: Re: [PATCH v3 05/26] x86/kexec: Make relocate_kernel_64.S objtool clean

On Tue, Mar 24, 2020 at 04:31:18PM +0100, Peter Zijlstra wrote:
> Having fixed the biggest objtool issue in this file; fix up the rest
> and remove the exception.
>
> Suggested-by: Josh Poimboeuf <[email protected]>
> Signed-off-by: Peter Zijlstra (Intel) <[email protected]>

Acked-by: Josh Poimboeuf <[email protected]>

--
Josh

2020-03-25 09:57:02

by Miroslav Benes

[permalink] [raw]
Subject: Re: [PATCH v3 05/26] x86/kexec: Make relocate_kernel_64.S objtool clean

On Tue, 24 Mar 2020, Peter Zijlstra wrote:

> Having fixed the biggest objtool issue in this file; fix up the rest
> and remove the exception.
>
> Suggested-by: Josh Poimboeuf <[email protected]>
> Signed-off-by: Peter Zijlstra (Intel) <[email protected]>

Reviewed-by: Miroslav Benes <[email protected]>

M

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 <[email protected]>
AuthorDate: Tue, 24 Mar 2020 15:35:42 +01:00
Committer: Peter Zijlstra <[email protected]>
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 <[email protected]>
Signed-off-by: Peter Zijlstra (Intel) <[email protected]>
Reviewed-by: Miroslav Benes <[email protected]>
Acked-by: Josh Poimboeuf <[email protected]>
Link: https://lkml.kernel.org/r/[email protected]
---
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