From 24f94fca23ad7c45806a1428331e1d602dfd8604 Mon Sep 17 00:00:00 2001 From: Andrew Cooper Date: Tue, 12 May 2020 19:18:37 +0100 Subject: [PATCH] x86/build32: Discard all orphaned sections Linkers may put orphaned sections ahead of .text, which breaks the calling requirements. A concrete example is Ubuntu's GCC-9 default of enabling -fcf-protection which causes us to try and execute .note.gnu.properties during Xen's boot. Put .got.plt in its own section as it specifically needs preserving from the linkers point of view, and discard everything else. This will hopefully be more robust to other unexpected toolchain properties. Fixes boot from an Ubuntu build of Xen. Reported-by: Jason Andryuk Signed-off-by: Andrew Cooper Tested-by: Jason Andryuk Acked-by: Jan Beulich --- xen/arch/x86/boot/build32.lds | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-) diff --git a/xen/arch/x86/boot/build32.lds b/xen/arch/x86/boot/build32.lds index da35aee910..97454b40ff 100644 --- a/xen/arch/x86/boot/build32.lds +++ b/xen/arch/x86/boot/build32.lds @@ -31,7 +31,7 @@ SECTIONS *(.bss.*) } - /DISCARD/ : { + .got.plt : { /* * PIC/PIE executable contains .got.plt section even if it is not linked * with dynamic libraries. In such case it is just placeholder for @@ -47,6 +47,14 @@ SECTIONS * * Please check build32.mk for more details. */ - /* *(.got.plt) */ + *(.got.plt) + } + + /DISCARD/ : { + /* + * Discard everything else, to prevent linkers from putting + * orphaned sections ahead of .text, which needs to be first. + */ + *(*) } } -- 2.30.2