From 5354e84598f264793265cc99b4be2a2295826c86 Mon Sep 17 00:00:00 2001 From: Kees Cook Date: Fri, 21 Aug 2020 12:43:05 -0700 Subject: [PATCH] x86/build: Add asserts for unwanted sections In preparation for warning on orphan sections, 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 Signed-off-by: Ingo Molnar Link: https://lore.kernel.org/r/20200821194310.3089815-25-keescook@chromium.org --- arch/x86/kernel/vmlinux.lds.S | 24 ++++++++++++++++++++++++ 1 file changed, 24 insertions(+) diff --git a/arch/x86/kernel/vmlinux.lds.S b/arch/x86/kernel/vmlinux.lds.S index 4b1b936a6e7df..45d72447df849 100644 --- a/arch/x86/kernel/vmlinux.lds.S +++ b/arch/x86/kernel/vmlinux.lds.S @@ -427,6 +427,30 @@ SECTIONS SIZEOF(.got.plt) == 0xc, #endif "Unexpected GOT/PLT entries detected!") + + /* + * Sections that should stay zero sized, which is safer to + * explicitly check instead of blindly discarding. + */ + .got : { + *(.got) *(.igot.*) + } + ASSERT(SIZEOF(.got) == 0, "Unexpected GOT entries detected!") + + .plt : { + *(.plt) *(.plt.*) *(.iplt) + } + ASSERT(SIZEOF(.plt) == 0, "Unexpected run-time procedure linkages detected!") + + .rel.dyn : { + *(.rel.*) *(.rel_*) + } + ASSERT(SIZEOF(.rel.dyn) == 0, "Unexpected run-time relocations (.rel) detected!") + + .rela.dyn : { + *(.rela.*) *(.rela_*) + } + ASSERT(SIZEOF(.rela.dyn) == 0, "Unexpected run-time relocations (.rela) detected!") } #ifdef CONFIG_X86_32 -- 2.49.0