From 10ebd8556b7990499c896a550e3d416b444211e6 Mon Sep 17 00:00:00 2001
From: hc <hc@nodka.com>
Date: Fri, 10 May 2024 02:23:07 +0000
Subject: [PATCH] add led
---
kernel/arch/arm64/kernel/kaslr.c | 115 ++++++++++++++++++++++++++++++++++-----------------------
1 files changed, 69 insertions(+), 46 deletions(-)
diff --git a/kernel/arch/arm64/kernel/kaslr.c b/kernel/arch/arm64/kernel/kaslr.c
index 92bb534..341342b 100644
--- a/kernel/arch/arm64/kernel/kaslr.c
+++ b/kernel/arch/arm64/kernel/kaslr.c
@@ -1,9 +1,6 @@
+// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (C) 2016 Linaro Ltd <ard.biesheuvel@linaro.org>
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License version 2 as
- * published by the Free Software Foundation.
*/
#include <linux/cache.h>
@@ -13,15 +10,25 @@
#include <linux/mm_types.h>
#include <linux/sched.h>
#include <linux/types.h>
+#include <linux/pgtable.h>
+#include <linux/random.h>
#include <asm/cacheflush.h>
#include <asm/fixmap.h>
#include <asm/kernel-pgtable.h>
#include <asm/memory.h>
#include <asm/mmu.h>
-#include <asm/pgtable.h>
#include <asm/sections.h>
+#include <asm/setup.h>
+enum kaslr_status {
+ KASLR_ENABLED,
+ KASLR_DISABLED_CMDLINE,
+ KASLR_DISABLED_NO_SEED,
+ KASLR_DISABLED_FDT_REMAP,
+};
+
+static enum kaslr_status __initdata kaslr_status;
u64 __ro_after_init module_alloc_base;
u16 __initdata memstart_offset_seed;
@@ -44,26 +51,7 @@
return ret;
}
-static __init const u8 *kaslr_get_cmdline(void *fdt)
-{
- static __initconst const u8 default_cmdline[] = CONFIG_CMDLINE;
-
- if (!IS_ENABLED(CONFIG_CMDLINE_FORCE)) {
- int node;
- const u8 *prop;
-
- node = fdt_path_offset(fdt, "/chosen");
- if (node < 0)
- goto out;
-
- prop = fdt_getprop(fdt, node, "bootargs", NULL);
- if (!prop)
- goto out;
- return prop;
- }
-out:
- return default_cmdline;
-}
+struct arm64_ftr_override kaslr_feature_override __initdata;
/*
* This routine will be executed with the kernel mapped at its default virtual
@@ -73,12 +61,11 @@
* 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;
- const u8 *cmdline, *str;
- int size;
+ unsigned long raw;
/*
* Set a reasonable default for module_alloc_base in case
@@ -92,51 +79,66 @@
* 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);
- if (!fdt)
+ fdt = get_early_fdt_ptr();
+ if (!fdt) {
+ kaslr_status = KASLR_DISABLED_FDT_REMAP;
return 0;
+ }
/*
* Retrieve (and wipe) the seed from the FDT
*/
seed = get_kaslr_seed(fdt);
- if (!seed)
- return 0;
/*
* Check if 'nokaslr' appears on the command line, and
* return 0 if that is the case.
*/
- cmdline = kaslr_get_cmdline(fdt);
- str = strstr(cmdline, "nokaslr");
- if (str == cmdline || (str > cmdline && *(str - 1) == ' '))
+ if (kaslr_feature_override.val & kaslr_feature_override.mask & 0xf) {
+ kaslr_status = KASLR_DISABLED_CMDLINE;
return 0;
+ }
+
+ /*
+ * Mix in any entropy obtainable architecturally if enabled
+ * and supported.
+ */
+
+ if (arch_get_random_seed_long_early(&raw))
+ seed ^= raw;
+
+ if (!seed) {
+ kaslr_status = KASLR_DISABLED_NO_SEED;
+ return 0;
+ }
/*
* OK, so we are proceeding with KASLR enabled. Calculate a suitable
* kernel image offset from the seed. Let's place the kernel in the
- * middle half of the VMALLOC area (VA_BITS - 2), and stay clear of
+ * middle half of the VMALLOC area (VA_BITS_MIN - 2), and stay clear of
* the lower and upper quarters to avoid colliding with other
* allocations.
* Even if we could randomize at page granularity for 16k and 64k pages,
* let's always round to 2 MB so we don't interfere with the ability to
* map using contiguous PTEs
*/
- mask = ((1UL << (VA_BITS - 2)) - 1) & ~(SZ_2M - 1);
- offset = BIT(VA_BITS - 3) + (seed & mask);
+ mask = ((1UL << (VA_BITS_MIN - 2)) - 1) & ~(SZ_2M - 1);
+ offset = BIT(VA_BITS_MIN - 3) + (seed & mask);
/* use the top 16 bits to randomize the linear region */
memstart_offset_seed = seed >> 48;
- if (IS_ENABLED(CONFIG_KASAN))
+ if (!IS_ENABLED(CONFIG_KASAN_VMALLOC) &&
+ (IS_ENABLED(CONFIG_KASAN_GENERIC) ||
+ IS_ENABLED(CONFIG_KASAN_SW_TAGS)))
/*
- * KASAN does not expect the module region to intersect the
- * vmalloc region, since shadow memory is allocated for each
- * module at load time, whereas the vmalloc region is shadowed
- * by KASAN zero pages. So keep modules out of the vmalloc
- * region if KASAN is enabled, and put the kernel well within
- * 4 GB of the module region.
+ * KASAN without KASAN_VMALLOC does not expect the module region
+ * to intersect the vmalloc region, since shadow memory is
+ * allocated for each module at load time, whereas the vmalloc
+ * region is shadowed by KASAN zero pages. So keep modules
+ * out of the vmalloc region if KASAN is enabled without
+ * KASAN_VMALLOC, and put the kernel well within 4 GB of the
+ * module region.
*/
return offset % SZ_2G;
@@ -173,3 +175,24 @@
return offset;
}
+
+static int __init kaslr_init(void)
+{
+ switch (kaslr_status) {
+ case KASLR_ENABLED:
+ pr_info("KASLR enabled\n");
+ break;
+ case KASLR_DISABLED_CMDLINE:
+ pr_info("KASLR disabled on command line\n");
+ break;
+ case KASLR_DISABLED_NO_SEED:
+ pr_warn("KASLR disabled due to lack of seed\n");
+ break;
+ case KASLR_DISABLED_FDT_REMAP:
+ pr_warn("KASLR disabled due to FDT remapping failure\n");
+ break;
+ }
+
+ return 0;
+}
+core_initcall(kaslr_init)
--
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