[PATCH v4 01/17] vmlinux.lds.h: Add .gnu.version* to DISCARDS

From: Kees Cook
Date: Mon Jun 29 2020 - 16:56:05 EST


For vmlinux linking, no architecture uses the .gnu.version* sections,
so remove it via the common DISCARDS macro in preparation for adding
--orphan-handling=warn more widely. This is a work-around for what
appears to be a bug[1] in ld.bfd which warns for this synthetic section
even when none is found in input objects, and even when no section is
emitted for an output object[2].

[1] https://sourceware.org/bugzilla/show_bug.cgi?id=26153
[2] https://lore.kernel.org/lkml/202006221524.CEB86E036B@keescook/

Reviewed-by: Fangrui Song <maskray@xxxxxxxxxx>
Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx>
---
include/asm-generic/vmlinux.lds.h | 2 ++
1 file changed, 2 insertions(+)

diff --git a/include/asm-generic/vmlinux.lds.h b/include/asm-generic/vmlinux.lds.h
index db600ef218d7..1248a206be8d 100644
--- a/include/asm-generic/vmlinux.lds.h
+++ b/include/asm-generic/vmlinux.lds.h
@@ -934,6 +934,8 @@
*(.discard) \
*(.discard.*) \
*(.modinfo) \
+ /* ld.bfd warns about .gnu.version* even when not emitted */ \
+ *(.gnu.version*) \
}

/**
--
2.25.1