The following commit has been merged into the core/build branch of tip: Commit-ID: 815d680771ae09080d2da83dac2647c08cdf99ce Gitweb: https://git.kernel.org/tip/815d680771ae09080d2da83dac2647c08cdf99ce Author: Kees Cook <keesc...@chromium.org> AuthorDate: Fri, 21 Aug 2020 12:43:04 -07:00 Committer: Ingo Molnar <mi...@kernel.org> CommitterDate: Tue, 01 Sep 2020 10:03:18 +02:00
x86/build: Enforce an empty .got.plt section The .got.plt section should always be zero (or filled only with the linker-generated lazy dispatch entry). Enforce this with an assert and mark the section as INFO. This is more sensitive than just blindly discarding the section. Signed-off-by: Kees Cook <keesc...@chromium.org> Signed-off-by: Ingo Molnar <mi...@kernel.org> Link: https://lore.kernel.org/r/20200821194310.3089815-24-keesc...@chromium.org --- arch/x86/kernel/vmlinux.lds.S | 14 +++++++++++++- 1 file changed, 13 insertions(+), 1 deletion(-) diff --git a/arch/x86/kernel/vmlinux.lds.S b/arch/x86/kernel/vmlinux.lds.S index 0cc035c..4b1b936 100644 --- a/arch/x86/kernel/vmlinux.lds.S +++ b/arch/x86/kernel/vmlinux.lds.S @@ -414,8 +414,20 @@ SECTIONS ELF_DETAILS DISCARDS -} + /* + * Make sure that the .got.plt is either completely empty or it + * contains only the lazy dispatch entries. + */ + .got.plt (INFO) : { *(.got.plt) } + ASSERT(SIZEOF(.got.plt) == 0 || +#ifdef CONFIG_X86_64 + SIZEOF(.got.plt) == 0x18, +#else + SIZEOF(.got.plt) == 0xc, +#endif + "Unexpected GOT/PLT entries detected!") +} #ifdef CONFIG_X86_32 /*
