Commit f6f0c436 authored by Marc Zyngier's avatar Marc Zyngier Committed by Will Deacon
Browse files

arm64: Extract early FDT mapping from kaslr_early_init() 



As we want to parse more options very early in the kernel lifetime,
let's always map the FDT early. This is achieved by moving that
code out of kaslr_early_init().

No functional change expected.

Signed-off-by: default avatarMarc Zyngier <maz@kernel.org>
Acked-by: default avatarCatalin Marinas <catalin.marinas@arm.com>
Acked-by: default avatarDavid Brazdil <dbrazdil@google.com>
Link: https://lore.kernel.org/r/20210208095732.3267263-13-maz@kernel.org


[will: Ensue KASAN is enabled before running C code]
Signed-off-by: default avatarWill Deacon <will@kernel.org>
parent b3341ae0

arch/arm64/include/asm/setup.h

0 → 100644
+11 −0
Original line number Diff line number Diff line 
// SPDX-License-Identifier: GPL-2.0



#ifndef __ARM64_ASM_SETUP_H

#define __ARM64_ASM_SETUP_H



#include <uapi/asm/setup.h>



void *get_early_fdt_ptr(void);

void early_fdt_map(u64 dt_phys);



#endif

arch/arm64/kernel/head.S

+2 −1
Original line number Diff line number Diff line
@@ -436,10 +436,11 @@ SYM_FUNC_START_LOCAL(__primary_switched) 
#if defined(CONFIG_KASAN_GENERIC) || defined(CONFIG_KASAN_SW_TAGS)

	bl	kasan_early_init

#endif

	mov	x0, x21				// pass FDT address in x0

	bl	early_fdt_map			// Try mapping the FDT early

#ifdef CONFIG_RANDOMIZE_BASE

	tst	x23, ~(MIN_KIMG_ALIGN - 1)	// already running randomized?

	b.ne	0f

	mov	x0, x21				// pass FDT address in x0

	bl	kaslr_early_init		// parse FDT for KASLR options

	cbz	x0, 0f				// KASLR disabled? just proceed

	orr	x23, x23, x0			// record KASLR offset

arch/arm64/kernel/kaslr.c

+3 −4
Original line number Diff line number Diff line
@@ -19,6 +19,7 @@ 
#include <asm/memory.h>

#include <asm/mmu.h>

#include <asm/sections.h>

#include <asm/setup.h>



enum kaslr_status {

	KASLR_ENABLED,
@@ -92,12 +93,11 @@ static __init bool is_kaslr_disabled_cmdline(void *fdt) 
 * containing function pointers) to be reinitialized, and zero-initialized

 * .bss variables will be reset to 0.

 */

u64 __init kaslr_early_init(u64 dt_phys)

u64 __init kaslr_early_init(void)

{

	void *fdt;

	u64 seed, offset, mask, module_range;

	unsigned long raw;

	int size;



	/*

	 * Set a reasonable default for module_alloc_base in case
@@ -111,8 +111,7 @@ u64 __init kaslr_early_init(u64 dt_phys) 
	 * and proceed with KASLR disabled. We will make another

	 * attempt at mapping the FDT in setup_machine()

	 */

	early_fixmap_init();

	fdt = fixmap_remap_fdt(dt_phys, &size, PAGE_KERNEL);

	fdt = get_early_fdt_ptr();

	if (!fdt) {

		kaslr_status = KASLR_DISABLED_FDT_REMAP;

		return 0;

arch/arm64/kernel/setup.c

+15 −0
Original line number Diff line number Diff line
@@ -168,6 +168,21 @@ static void __init smp_build_mpidr_hash(void) 
		pr_warn("Large number of MPIDR hash buckets detected\n");

}



static void *early_fdt_ptr __initdata;



void __init *get_early_fdt_ptr(void)

{

	return early_fdt_ptr;

}



asmlinkage void __init early_fdt_map(u64 dt_phys)

{

	int fdt_size;



	early_fixmap_init();

	early_fdt_ptr = fixmap_remap_fdt(dt_phys, &fdt_size, PAGE_KERNEL);

}



static void __init setup_machine_fdt(phys_addr_t dt_phys)

{

	int size;