1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * Copyright (C) 2016 Linaro Ltd <ard.biesheuvel@linaro.org> 4 */ 5 6 #include <linux/cache.h> 7 #include <linux/init.h> 8 #include <linux/printk.h> 9 10 #include <asm/cpufeature.h> 11 #include <asm/memory.h> 12 13 bool __ro_after_init __kaslr_is_enabled = false; 14 15 void __init kaslr_init(void) 16 { 17 if (kaslr_disabled_cmdline()) { 18 pr_info("KASLR disabled on command line\n"); 19 return; 20 } 21 22 /* 23 * The KASLR offset modulo MIN_KIMG_ALIGN is taken from the physical 24 * placement of the image rather than from the seed, so a displacement 25 * of less than MIN_KIMG_ALIGN means that no seed was provided. 26 */ 27 if (kaslr_offset() < MIN_KIMG_ALIGN) { 28 pr_warn("KASLR disabled due to lack of seed\n"); 29 return; 30 } 31 32 pr_info("KASLR enabled\n"); 33 __kaslr_is_enabled = true; 34 } 35 36 static int __init parse_nokaslr(char *unused) 37 { 38 /* nokaslr param handling is done by early cpufeature code */ 39 return 0; 40 } 41 early_param("nokaslr", parse_nokaslr); 42