The following commit has been merged into the core/build branch of tip: Commit-ID: be2881824ae9eb92a35b094f734f9ca7339ddf6d Gitweb: https://git.kernel.org/tip/be2881824ae9eb92a35b094f734f9ca7339ddf6d Author: Kees Cook <keesc...@chromium.org> AuthorDate: Fri, 21 Aug 2020 12:42:54 -07:00 Committer: Ingo Molnar <mi...@kernel.org> CommitterDate: Tue, 01 Sep 2020 09:50:37 +02:00
arm64/build: Assert for unwanted sections In preparation for warning on orphan 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). Suggested-by: Ard Biesheuvel <a...@kernel.org> Signed-off-by: Kees Cook <keesc...@chromium.org> Signed-off-by: Ingo Molnar <mi...@kernel.org> Cc: Catalin Marinas <catalin.mari...@arm.com> Cc: Will Deacon <w...@kernel.org> Link: https://lore.kernel.org/r/20200821194310.3089815-14-keesc...@chromium.org --- arch/arm64/kernel/vmlinux.lds.S | 20 ++++++++++++++++++++ 1 file changed, 20 insertions(+) diff --git a/arch/arm64/kernel/vmlinux.lds.S b/arch/arm64/kernel/vmlinux.lds.S index 16eb2ef..e8847ca 100644 --- a/arch/arm64/kernel/vmlinux.lds.S +++ b/arch/arm64/kernel/vmlinux.lds.S @@ -121,6 +121,14 @@ SECTIONS *(.got) /* Global offset table */ } + /* + * Make sure that the .got.plt is either completely empty or it + * contains only the lazy dispatch entries. + */ + .got.plt : { *(.got.plt) } + ASSERT(SIZEOF(.got.plt) == 0 || SIZEOF(.got.plt) == 0x18, + "Unexpected GOT/PLT entries detected!") + . = ALIGN(SEGMENT_ALIGN); _etext = .; /* End of text section */ @@ -243,6 +251,18 @@ SECTIONS ELF_DETAILS HEAD_SYMBOLS + + /* + * Sections that should stay zero sized, which is safer to + * explicitly check instead of blindly discarding. + */ + .plt : { + *(.plt) *(.plt.*) *(.iplt) *(.igot) + } + ASSERT(SIZEOF(.plt) == 0, "Unexpected run-time procedure linkages detected!") + + .data.rel.ro : { *(.data.rel.ro) } + ASSERT(SIZEOF(.data.rel.ro) == 0, "Unexpected RELRO detected!") } #include "image-vars.h"
