x86/boot/compressed: Remove, discard, or assert for unwanted sections

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 <keescook@chromium.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20200821194310.3089815-28-keescook@chromium.org
This commit is contained in:
Kees Cook 2020-08-21 12:43:08 -07:00 committed by Ingo Molnar
parent 7cf891a400
commit d1c0272bc1
2 changed files with 13 additions and 2 deletions

View File

@ -50,6 +50,7 @@ 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)

View File

@ -72,6 +72,11 @@ SECTIONS
ELF_DETAILS
DISCARDS
/DISCARD/ : {
*(.dynamic) *(.dynsym) *(.dynstr) *(.dynbss)
*(.hash) *(.gnu.hash)
*(.note.*)
}
.got.plt (INFO) : {
*(.got.plt)
@ -93,13 +98,18 @@ SECTIONS
}
ASSERT(SIZEOF(.got) == 0, "Unexpected GOT entries detected!")
.plt : {
*(.plt) *(.plt.*)
}
ASSERT(SIZEOF(.plt) == 0, "Unexpected run-time procedure linkages detected!")
.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!")
}