Commit 815d6807 authored Aug 21, 2020 by Kees Cook Committed by Ingo Molnar Sep 01, 2020

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 <keescook@chromium.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20200821194310.3089815-24-keescook@chromium.org

parent a850958c

arch/x86/kernel/vmlinux.lds.S

+13 −1

Original line number	Diff line number	Diff line
		@@ -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
		/*

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