| 1 | // SPDX-License-Identifier: GPL-2.0-only |
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| 2 | /* |
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| 3 | * Copyright (C) 2016 Linaro Ltd <ard.biesheuvel@linaro.org> |
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| 4 | */ |
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| 5 | |
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| 6 | #include <linux/cache.h> |
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| 7 | #include <linux/init.h> |
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| 8 | #include <linux/printk.h> |
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| 9 | |
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| 10 | #include <asm/cpufeature.h> |
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| 11 | #include <asm/memory.h> |
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| 12 | |
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| 13 | u16 __initdata memstart_offset_seed; |
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| 14 | |
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| 15 | bool __ro_after_init __kaslr_is_enabled = false; |
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| 16 | |
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| 17 | void __init kaslr_init(void) |
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| 18 | { |
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| 19 | if (kaslr_disabled_cmdline()) { |
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| 20 | pr_info("KASLR disabled on command line\n" ); |
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| 21 | return; |
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| 22 | } |
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| 23 | |
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| 24 | /* |
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| 25 | * The KASLR offset modulo MIN_KIMG_ALIGN is taken from the physical |
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| 26 | * placement of the image rather than from the seed, so a displacement |
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| 27 | * of less than MIN_KIMG_ALIGN means that no seed was provided. |
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| 28 | */ |
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| 29 | if (kaslr_offset() < MIN_KIMG_ALIGN) { |
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| 30 | pr_warn("KASLR disabled due to lack of seed\n" ); |
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| 31 | return; |
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| 32 | } |
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| 33 | |
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| 34 | pr_info("KASLR enabled\n" ); |
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| 35 | __kaslr_is_enabled = true; |
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| 36 | } |
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| 37 | |
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| 38 | static int __init parse_nokaslr(char *unused) |
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| 39 | { |
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| 40 | /* nokaslr param handling is done by early cpufeature code */ |
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| 41 | return 0; |
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| 42 | } |
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| 43 | early_param("nokaslr" , parse_nokaslr); |
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| 44 | |
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