This is a note to let you know that I've just added the patch titled
x86/xen: Support objtool validation in xen-asm.S
to the 5.10-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
x86-xen-support-objtool-validation-in-xen-asm.s.patch
and it can be found in the queue-5.10 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From foo@baz Tue Jul 12 05:07:35 PM CEST 2022
From: Josh Poimboeuf <jpoimboe@xxxxxxxxxx>
Date: Thu, 21 Jan 2021 15:29:28 -0600
Subject: x86/xen: Support objtool validation in xen-asm.S
From: Josh Poimboeuf <jpoimboe@xxxxxxxxxx>
commit cde07a4e4434ddfb9b1616ac971edf6d66329804 upstream.
The OBJECT_FILES_NON_STANDARD annotation is used to tell objtool to
ignore a file. File-level ignores won't work when validating vmlinux.o.
Tweak the ELF metadata and unwind hints to allow objtool to follow the
code.
Cc: Juergen Gross <jgross@xxxxxxxx>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@xxxxxxxxxx>
Signed-off-by: Josh Poimboeuf <jpoimboe@xxxxxxxxxx>
Link: https://lore.kernel.org/r/8b042a09c69e8645f3b133ef6653ba28f896807d.1611263462.git.jpoimboe@xxxxxxxxxx
Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
arch/x86/xen/Makefile | 1 -
arch/x86/xen/xen-asm.S | 29 +++++++++++++++++++----------
2 files changed, 19 insertions(+), 11 deletions(-)
--- a/arch/x86/xen/Makefile
+++ b/arch/x86/xen/Makefile
@@ -1,5 +1,4 @@
# SPDX-License-Identifier: GPL-2.0
-OBJECT_FILES_NON_STANDARD_xen-asm.o := y
ifdef CONFIG_FUNCTION_TRACER
# Do not profile debug and lowlevel utilities
--- a/arch/x86/xen/xen-asm.S
+++ b/arch/x86/xen/xen-asm.S
@@ -14,6 +14,7 @@
#include <asm/thread_info.h>
#include <asm/asm.h>
#include <asm/frame.h>
+#include <asm/unwind_hints.h>
#include <xen/interface/xen.h>
@@ -147,6 +148,7 @@ SYM_FUNC_END(xen_read_cr2_direct);
.macro xen_pv_trap name
SYM_CODE_START(xen_\name)
+ UNWIND_HINT_EMPTY
pop %rcx
pop %r11
jmp \name
@@ -186,6 +188,7 @@ xen_pv_trap asm_exc_xen_hypervisor_callb
SYM_CODE_START(xen_early_idt_handler_array)
i = 0
.rept NUM_EXCEPTION_VECTORS
+ UNWIND_HINT_EMPTY
pop %rcx
pop %r11
jmp early_idt_handler_array + i*EARLY_IDT_HANDLER_SIZE
@@ -212,11 +215,13 @@ hypercall_iret = hypercall_page + __HYPE
* rsp->rax }
*/
SYM_CODE_START(xen_iret)
+ UNWIND_HINT_EMPTY
pushq $0
jmp hypercall_iret
SYM_CODE_END(xen_iret)
SYM_CODE_START(xen_sysret64)
+ UNWIND_HINT_EMPTY
/*
* We're already on the usermode stack at this point, but
* still with the kernel gs, so we can easily switch back.
@@ -271,7 +276,8 @@ SYM_CODE_END(xenpv_restore_regs_and_retu
*/
/* Normal 64-bit system call target */
-SYM_FUNC_START(xen_syscall_target)
+SYM_CODE_START(xen_syscall_target)
+ UNWIND_HINT_EMPTY
popq %rcx
popq %r11
@@ -284,12 +290,13 @@ SYM_FUNC_START(xen_syscall_target)
movq $__USER_CS, 1*8(%rsp)
jmp entry_SYSCALL_64_after_hwframe
-SYM_FUNC_END(xen_syscall_target)
+SYM_CODE_END(xen_syscall_target)
#ifdef CONFIG_IA32_EMULATION
/* 32-bit compat syscall target */
-SYM_FUNC_START(xen_syscall32_target)
+SYM_CODE_START(xen_syscall32_target)
+ UNWIND_HINT_EMPTY
popq %rcx
popq %r11
@@ -302,10 +309,11 @@ SYM_FUNC_START(xen_syscall32_target)
movq $__USER32_CS, 1*8(%rsp)
jmp entry_SYSCALL_compat_after_hwframe
-SYM_FUNC_END(xen_syscall32_target)
+SYM_CODE_END(xen_syscall32_target)
/* 32-bit compat sysenter target */
-SYM_FUNC_START(xen_sysenter_target)
+SYM_CODE_START(xen_sysenter_target)
+ UNWIND_HINT_EMPTY
/*
* NB: Xen is polite and clears TF from EFLAGS for us. This means
* that we don't need to guard against single step exceptions here.
@@ -322,17 +330,18 @@ SYM_FUNC_START(xen_sysenter_target)
movq $__USER32_CS, 1*8(%rsp)
jmp entry_SYSENTER_compat_after_hwframe
-SYM_FUNC_END(xen_sysenter_target)
+SYM_CODE_END(xen_sysenter_target)
#else /* !CONFIG_IA32_EMULATION */
-SYM_FUNC_START_ALIAS(xen_syscall32_target)
-SYM_FUNC_START(xen_sysenter_target)
+SYM_CODE_START(xen_syscall32_target)
+SYM_CODE_START(xen_sysenter_target)
+ UNWIND_HINT_EMPTY
lea 16(%rsp), %rsp /* strip %rcx, %r11 */
mov $-ENOSYS, %rax
pushq $0
jmp hypercall_iret
-SYM_FUNC_END(xen_sysenter_target)
-SYM_FUNC_END_ALIAS(xen_syscall32_target)
+SYM_CODE_END(xen_sysenter_target)
+SYM_CODE_END(xen_syscall32_target)
#endif /* CONFIG_IA32_EMULATION */
Patches currently in stable-queue which might be from jpoimboe@xxxxxxxxxx are
queue-5.10/x86-bugs-enable-stibp-for-jmp2ret.patch
queue-5.10/objtool-assume-only-elf-functions-do-sibling-calls.patch
queue-5.10/objtool-support-retpoline-jump-detection-for-vmlinux.o.patch
queue-5.10/x86-xen-support-objtool-vmlinux.o-validation-in-xen-head.s.patch
queue-5.10/objtool-x86-replace-alternatives-with-.retpoline_sites.patch
queue-5.10/objtool-don-t-make-.altinstructions-writable.patch
queue-5.10/x86-alternative-handle-jcc-__x86_indirect_thunk_-reg.patch
queue-5.10/x86-xen-support-objtool-validation-in-xen-asm.s.patch
queue-5.10/x86-retpoline-remove-unused-replacement-symbols.patch
queue-5.10/objtool-support-stack-layout-changes-in-alternatives.patch
queue-5.10/bpf-x86-respect-x86_feature_retpoline.patch
queue-5.10/objtool-fix-type-of-reloc-addend.patch
queue-5.10/x86-retpoline-create-a-retpoline-thunk-array.patch
queue-5.10/x86-asm-fix-register-order.patch
queue-5.10/objtool-make-.altinstructions-section-entry-size-consistent.patch
queue-5.10/bpf-x86-simplify-computing-label-offsets.patch
queue-5.10/objtool-refactor-orc-section-generation.patch
queue-5.10/objtool-fix-code-relocs-vs-weak-symbols.patch
queue-5.10/objtool-combine-unwind_hint_ret_offset-and-unwind_hint_func.patch
queue-5.10/x86-asm-fixup-odd-gen-for-each-reg.h-usage.patch
queue-5.10/x86-alternative-add-debug-prints-to-apply_retpolines.patch
queue-5.10/objtool-remove-reloc-symbol-type-checks-in-get_alt_entry.patch
queue-5.10/objtool-classify-symbols.patch
queue-5.10/objtool-add-alt_group-struct.patch
queue-5.10/x86-retpoline-move-the-retpoline-thunk-declarations-to-nospec-branch.h.patch
queue-5.10/objtool-support-asm-jump-tables.patch
queue-5.10/x86-alternative-implement-.retpoline_sites-support.patch
queue-5.10/x86-alternative-try-inline-spectre_v2-retpoline-amd.patch
queue-5.10/objtool-explicitly-avoid-self-modifying-code-in-.altinstr_replacement.patch
queue-5.10/objtool-create-reloc-sections-implicitly.patch
queue-5.10/objtool-default-ignore-int3-for-unreachable.patch
queue-5.10/objtool-teach-get_alt_entry-about-more-relocation-types.patch
