In preparation for warning on orphan sections, stop the linker from
generating the .eh_frame* sections, discard unwanted non-zero-sized
generated sections, and enforce other expected-to-be-zero-sized sections
(since discarding them might hide problems with them suddenly gaining
unexpected entries).

Signed-off-by: Kees Cook <keesc...@chromium.org>
---
 arch/x86/boot/compressed/Makefile      |  1 +
 arch/x86/boot/compressed/vmlinux.lds.S | 14 ++++++++++++--
 2 files changed, 13 insertions(+), 2 deletions(-)

diff --git a/arch/x86/boot/compressed/Makefile 
b/arch/x86/boot/compressed/Makefile
index 96d53e300ab6..43b49e1f5b6d 100644
--- a/arch/x86/boot/compressed/Makefile
+++ b/arch/x86/boot/compressed/Makefile
@@ -49,6 +49,7 @@ GCOV_PROFILE := n
 UBSAN_SANITIZE :=n
 
 KBUILD_LDFLAGS := -m elf_$(UTS_MACHINE)
+KBUILD_LDFLAGS += $(call ld-option,--no-ld-generated-unwind-info)
 # Compressed kernel should be built as PIE since it may be loaded at any
 # address by the bootloader.
 LDFLAGS_vmlinux := -pie $(call ld-option, --no-dynamic-linker)
diff --git a/arch/x86/boot/compressed/vmlinux.lds.S 
b/arch/x86/boot/compressed/vmlinux.lds.S
index 42dea70a5091..1fb9809a9e61 100644
--- a/arch/x86/boot/compressed/vmlinux.lds.S
+++ b/arch/x86/boot/compressed/vmlinux.lds.S
@@ -83,6 +83,11 @@ SECTIONS
        ELF_DETAILS
 
        DISCARDS
+       /DISCARD/ : {
+               *(.dynamic) *(.dynsym) *(.dynstr) *(.dynbss)
+               *(.hash) *(.gnu.hash)
+               *(.note.*)
+       }
 
        /*
         * Sections that should stay zero sized, which is safer to
@@ -93,13 +98,18 @@ SECTIONS
        }
        ASSERT(SIZEOF(.got) == 0, "Unexpected GOT entries detected!")
 
+       .plt (NOLOAD) : {
+               *(.plt) *(.plt.*)
+       }
+       ASSERT(SIZEOF(.plt) == 0, "Unexpected run-time procedure linkages 
detected!")
+
        /* ld.lld does not like .rel* sections being made "NOLOAD". */
        .rel.dyn : {
-               *(.rel.*)
+               *(.rel.*) *(.rel_*)
        }
        ASSERT(SIZEOF(.rel.dyn) == 0, "Unexpected run-time relocations (.rel) 
detected!")
        .rela.dyn : {
-               *(.rela.*)
+               *(.rela.*) *(.rela_*)
        }
        ASSERT(SIZEOF(.rela.dyn) == 0, "Unexpected run-time relocations (.rela) 
detected!")
 }
-- 
2.25.1

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