linux/arch/arm64/kernel/kaslr.c
Oliver Upton acfdf34c7d Merge branch for-next/module-alloc into kvmarm/next
* for-next/module-alloc:
  : Drag in module VA rework to handle conflicts w/ sw feature refactor
  arm64: module: rework module VA range selection
  arm64: module: mandate MODULE_PLTS
  arm64: module: move module randomization to module.c
  arm64: kaslr: split kaslr/module initialization
  arm64: kasan: remove !KASAN_VMALLOC remnants
  arm64: module: remove old !KASAN_VMALLOC logic

Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2023-06-15 13:04:15 +00:00

38 lines
957 B
C

// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (C) 2016 Linaro Ltd <ard.biesheuvel@linaro.org>
*/
#include <linux/cache.h>
#include <linux/init.h>
#include <linux/printk.h>
#include <asm/cpufeature.h>
#include <asm/memory.h>
u16 __initdata memstart_offset_seed;
bool __ro_after_init __kaslr_is_enabled = false;
void __init kaslr_init(void)
{
if (cpuid_feature_extract_unsigned_field(arm64_sw_feature_override.val &
arm64_sw_feature_override.mask,
ARM64_SW_FEATURE_OVERRIDE_NOKASLR)) {
pr_info("KASLR disabled on command line\n");
return;
}
/*
* The KASLR offset modulo MIN_KIMG_ALIGN is taken from the physical
* placement of the image rather than from the seed, so a displacement
* of less than MIN_KIMG_ALIGN means that no seed was provided.
*/
if (kaslr_offset() < MIN_KIMG_ALIGN) {
pr_warn("KASLR disabled due to lack of seed\n");
return;
}
pr_info("KASLR enabled\n");
__kaslr_is_enabled = true;
}