1d2912cb1SThomas Gleixner // SPDX-License-Identifier: GPL-2.0-only 2f80fb3a3SArd Biesheuvel /* 3f80fb3a3SArd Biesheuvel * Copyright (C) 2016 Linaro Ltd <ard.biesheuvel@linaro.org> 4f80fb3a3SArd Biesheuvel */ 5f80fb3a3SArd Biesheuvel 65a9e3e15SJisheng Zhang #include <linux/cache.h> 7f80fb3a3SArd Biesheuvel #include <linux/init.h> 8e46b7103SMark Rutland #include <linux/printk.h> 9f80fb3a3SArd Biesheuvel 10e46b7103SMark Rutland #include <asm/cpufeature.h> 11f80fb3a3SArd Biesheuvel #include <asm/memory.h> 12f80fb3a3SArd Biesheuvel 13c031a421SArd Biesheuvel u16 __initdata memstart_offset_seed; 14f80fb3a3SArd Biesheuvel 156e13b6b9SMark Rutland bool __ro_after_init __kaslr_is_enabled = false; 166e13b6b9SMark Rutland 176e13b6b9SMark Rutland void __init kaslr_init(void) 18fc5a89f7SArd Biesheuvel { 19*af73b9a2SArd Biesheuvel if (kaslr_disabled_cmdline()) { 20fc5a89f7SArd Biesheuvel pr_info("KASLR disabled on command line\n"); 216e13b6b9SMark Rutland return; 22fc5a89f7SArd Biesheuvel } 23fc5a89f7SArd Biesheuvel 246e13b6b9SMark Rutland /* 256e13b6b9SMark Rutland * The KASLR offset modulo MIN_KIMG_ALIGN is taken from the physical 266e13b6b9SMark Rutland * placement of the image rather than from the seed, so a displacement 276e13b6b9SMark Rutland * of less than MIN_KIMG_ALIGN means that no seed was provided. 286e13b6b9SMark Rutland */ 296e13b6b9SMark Rutland if (kaslr_offset() < MIN_KIMG_ALIGN) { 30fc5a89f7SArd Biesheuvel pr_warn("KASLR disabled due to lack of seed\n"); 316e13b6b9SMark Rutland return; 32fc5a89f7SArd Biesheuvel } 33fc5a89f7SArd Biesheuvel 34fc5a89f7SArd Biesheuvel pr_info("KASLR enabled\n"); 356e13b6b9SMark Rutland __kaslr_is_enabled = true; 36f80fb3a3SArd Biesheuvel } 3750f17617SArd Biesheuvel 3850f17617SArd Biesheuvel static int __init parse_nokaslr(char *unused) 3950f17617SArd Biesheuvel { 4050f17617SArd Biesheuvel /* nokaslr param handling is done by early cpufeature code */ 4150f17617SArd Biesheuvel return 0; 4250f17617SArd Biesheuvel } 4350f17617SArd Biesheuvel early_param("nokaslr", parse_nokaslr); 44