This is a note to let you know that I've just added the patch titled
x86/xen: Support objtool vmlinux.o validation in xen-head.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-vmlinux.o-validation-in-xen-head.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 15:29:29 -0600
Subject: x86/xen: Support objtool vmlinux.o validation in xen-head.S
From: Josh Poimboeuf <jpoimboe@xxxxxxxxxx>
commit f4b4bc10b0b85ec66f1a9bf5dddf475e6695b6d2 upstream.
The Xen hypercall page is filled with zeros, causing objtool to fall
through all the empty hypercall functions until it reaches a real
function, resulting in a stack state mismatch.
The build-time contents of the hypercall page don't matter because the
page gets rewritten by the hypervisor. Make it more palatable to
objtool by making each hypervisor function a true empty function, with
nops and a return.
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/0883bde1d7a1fb3b6a4c952bc0200e873752f609.1611263462.git.jpoimboe@xxxxxxxxxx
Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
arch/x86/xen/xen-head.S | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
--- a/arch/x86/xen/xen-head.S
+++ b/arch/x86/xen/xen-head.S
@@ -68,8 +68,9 @@ SYM_CODE_END(asm_cpu_bringup_and_idle)
.balign PAGE_SIZE
SYM_CODE_START(hypercall_page)
.rept (PAGE_SIZE / 32)
- UNWIND_HINT_EMPTY
- .skip 32
+ UNWIND_HINT_FUNC
+ .skip 31, 0x90
+ ret
.endr
#define HYPERCALL(n) \
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
