[xen stable-4.18] xen/x86: prevent addition of .note.gnu.property if livepatch is enabled

[patchbot@xxxxxxx]

commit 1cbeb625a3551ad7e3184f9713875b584552df9b
Author:     Roger Pau Monné <roger.pau@xxxxxxxxxx>
AuthorDate: Tue Nov 12 13:54:56 2024 +0100
Commit:     Jan Beulich <jbeulich@xxxxxxxx>
CommitDate: Tue Nov 12 13:54:56 2024 +0100

    xen/x86: prevent addition of .note.gnu.property if livepatch is enabled
    
    GNU assembly that supports such feature will unconditionally add a
    .note.gnu.property section to object files.  The content of that section can
    change depending on the generated instructions.  The current logic in
    livepatch-build-tools doesn't know how to deal with such section changing
    as a result of applying a patch and rebuilding.
    
    Since .note.gnu.property is not consumed by the Xen build, suppress its
    addition when livepatch support is enabled.
    
    Signed-off-by: Roger Pau Monné <roger.pau@xxxxxxxxxx>
    Reviewed-by: Jan Beulich <jbeulich@xxxxxxxx>
    master commit: 718400a54dcfcc8a11958a6d953168f50944f002
    master date: 2024-11-11 13:19:45 +0100
---
 xen/arch/x86/arch.mk | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/xen/arch/x86/arch.mk b/xen/arch/x86/arch.mk
index 751fd8d410..aa55f54f69 100644
--- a/xen/arch/x86/arch.mk
+++ b/xen/arch/x86/arch.mk
@@ -46,6 +46,12 @@ CFLAGS-$(CONFIG_CC_IS_GCC) += -fno-jump-tables
 CFLAGS-$(CONFIG_CC_IS_CLANG) += -mretpoline-external-thunk
 endif
 
+# Disable the addition of a .note.gnu.property section to object files when
+# livepatch support is enabled.  The contents of that section can change
+# depending on the instructions used, and livepatch-build-tools doesn't know
+# how to deal with such changes.
+$(call 
cc-option-add,CFLAGS-$(CONFIG_LIVEPATCH),CC,-Wa$$(comma)-mx86-used-note=no)
+
 ifdef CONFIG_XEN_IBT
 # Force -fno-jump-tables to work around
 #   https://gcc.gnu.org/bugzilla/show_bug.cgi?id=104816
--
generated by git-patchbot for /home/xen/git/xen.git#stable-4.18