Commit 35350eb6 authored Dec 05, 2024 by Ard Biesheuvel Committed by Ingo Molnar Dec 05, 2024

x86/kernel: Move ENTRY_TEXT to the start of the image



Since commit:

  7734a0f3 ("x86/boot: Robustify calling startup_{32,64}() from the decompressor code")

it is no longer necessary for .head.text to appear at the start of the
image. Since ENTRY_TEXT needs to appear PMD-aligned, it is easier to
just place it at the start of the image, rather than line it up with the
end of the .text section. The amount of padding required should be the
same, but this arrangement also permits .head.text to be split off and
emitted separately, which is needed by a subsequent change.

Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Link: https://lore.kernel.org/r/20241205112804.3416920-14-ardb+git@google.com

parent 3b6f99a9

arch/x86/kernel/vmlinux.lds.S

+13 −13

Original line number	Diff line number	Diff line
		@@ -121,19 +121,6 @@ SECTIONS
		.text : AT(ADDR(.text) - LOAD_OFFSET) {
		_text = .;
		_stext = .;
		/* bootstrapping code */
		HEAD_TEXT
		TEXT_TEXT
		SCHED_TEXT
		LOCK_TEXT
		KPROBES_TEXT
		SOFTIRQENTRY_TEXT
		#ifdef CONFIG_MITIGATION_RETPOLINE
		*(.text..__x86.indirect_thunk)
		*(.text..__x86.return_thunk)
		#endif
		STATIC_CALL_TEXT

		ALIGN_ENTRY_TEXT_BEGIN
		*(.text..__x86.rethunk_untrain)
		ENTRY_TEXT
		@@ -147,6 +134,19 @@ SECTIONS
		*(.text..__x86.rethunk_safe)
		#endif
		ALIGN_ENTRY_TEXT_END

		/* bootstrapping code */
		HEAD_TEXT
		TEXT_TEXT
		SCHED_TEXT
		LOCK_TEXT
		KPROBES_TEXT
		SOFTIRQENTRY_TEXT
		#ifdef CONFIG_MITIGATION_RETPOLINE
		*(.text..__x86.indirect_thunk)
		*(.text..__x86.return_thunk)
		#endif
		STATIC_CALL_TEXT
		*(.gnu.warning)

		} :text = 0xcccccccc