Commit f21ba449 authored by Nicholas Piggin's avatar Nicholas Piggin Committed by Michael Ellerman
Browse files

powerpc/build: move got, toc, plt, branch_lt sections to read-only 



This moves linker-related tables from .data to read-only area.
Relocations are performed at early boot time before memory is protected,
after which there should be no modifications required.

Signed-off-by: default avatarNicholas Piggin <npiggin@gmail.com>
[mpe: Don't use SPECIAL as reported by lkp@intel.com]
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220916040755.2398112-4-npiggin@gmail.com
parent 1faa1235

arch/powerpc/kernel/vmlinux.lds.S

+22 −10
Original line number Diff line number Diff line
@@ -135,6 +135,10 @@ SECTIONS 
	/* Read-only data */

	RO_DATA(PAGE_SIZE)



	.branch_lt : AT(ADDR(.branch_lt) - LOAD_OFFSET) {

		*(.branch_lt)

	}



#ifdef CONFIG_PPC32

	.got1 : AT(ADDR(.got1) - LOAD_OFFSET) {

		*(.got1)
@@ -144,7 +148,25 @@ SECTIONS 
		*(.got2)

		__got2_end = .;

	}

	.got : AT(ADDR(.got) - LOAD_OFFSET) {

		*(.got)

		*(.got.plt)

	}

	.plt : AT(ADDR(.plt) - LOAD_OFFSET) {

		/* XXX: is .plt (and .got.plt) required? */

		*(.plt)

	}



#else /* CONFIG_PPC32 */

	.toc1 : AT(ADDR(.toc1) - LOAD_OFFSET) {

		*(.toc1)

	}



	.got : AT(ADDR(.got) - LOAD_OFFSET) ALIGN(256) {

		*(.got)

		*(.toc)

	}



	SOFT_MASK_TABLE(8)

	RESTART_TABLE(8)
@@ -333,21 +355,11 @@ SECTIONS 
		*(.data.rel*)

		*(SDATA_MAIN)

		*(.sdata2)

		*(.got.plt) *(.got)

		*(.plt)

		*(.branch_lt)

	}

#else

	.data : AT(ADDR(.data) - LOAD_OFFSET) {

		DATA_DATA

		*(.data.rel*)

		*(.toc1)

		*(.branch_lt)

	}



	.got : AT(ADDR(.got) - LOAD_OFFSET) ALIGN(256) {

		*(.got)

		*(.toc)

	}

#endif