![Jinbum Park](/assets/img/avatar_default.png)
Page mappings with full RWX permissions are a security risk.
x86, arm64 has an option to walk the page tables
and dump any bad pages.
(1404d6f13e
("arm64: dump: Add checking for writable and exectuable pages"))
Add a similar implementation for arm.
Reviewed-by: Kees Cook <keescook@chromium.org>
Tested-by: Laura Abbott <labbott@redhat.com>
Reviewed-by: Laura Abbott <labbott@redhat.com>
Signed-off-by: Jinbum Park <jinb.park7@gmail.com>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
806 lines
20 KiB
C
806 lines
20 KiB
C
/*
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* linux/arch/arm/mm/init.c
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*
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* Copyright (C) 1995-2005 Russell King
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*/
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#include <linux/kernel.h>
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#include <linux/errno.h>
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#include <linux/swap.h>
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#include <linux/init.h>
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#include <linux/bootmem.h>
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#include <linux/mman.h>
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#include <linux/sched/signal.h>
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#include <linux/sched/task.h>
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#include <linux/export.h>
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#include <linux/nodemask.h>
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#include <linux/initrd.h>
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#include <linux/of_fdt.h>
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#include <linux/highmem.h>
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#include <linux/gfp.h>
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#include <linux/memblock.h>
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#include <linux/dma-contiguous.h>
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#include <linux/sizes.h>
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#include <linux/stop_machine.h>
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#include <asm/cp15.h>
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#include <asm/mach-types.h>
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#include <asm/memblock.h>
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#include <asm/memory.h>
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#include <asm/prom.h>
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#include <asm/sections.h>
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#include <asm/setup.h>
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#include <asm/system_info.h>
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#include <asm/tlb.h>
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#include <asm/fixmap.h>
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#include <asm/ptdump.h>
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#include <asm/mach/arch.h>
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#include <asm/mach/map.h>
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#include "mm.h"
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#ifdef CONFIG_CPU_CP15_MMU
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unsigned long __init __clear_cr(unsigned long mask)
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{
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cr_alignment = cr_alignment & ~mask;
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return cr_alignment;
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}
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#endif
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static phys_addr_t phys_initrd_start __initdata = 0;
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static unsigned long phys_initrd_size __initdata = 0;
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static int __init early_initrd(char *p)
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{
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phys_addr_t start;
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unsigned long size;
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char *endp;
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start = memparse(p, &endp);
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if (*endp == ',') {
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size = memparse(endp + 1, NULL);
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phys_initrd_start = start;
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phys_initrd_size = size;
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}
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return 0;
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}
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early_param("initrd", early_initrd);
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static int __init parse_tag_initrd(const struct tag *tag)
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{
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pr_warn("ATAG_INITRD is deprecated; "
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"please update your bootloader.\n");
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phys_initrd_start = __virt_to_phys(tag->u.initrd.start);
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phys_initrd_size = tag->u.initrd.size;
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return 0;
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}
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__tagtable(ATAG_INITRD, parse_tag_initrd);
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static int __init parse_tag_initrd2(const struct tag *tag)
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{
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phys_initrd_start = tag->u.initrd.start;
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phys_initrd_size = tag->u.initrd.size;
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return 0;
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}
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__tagtable(ATAG_INITRD2, parse_tag_initrd2);
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static void __init find_limits(unsigned long *min, unsigned long *max_low,
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unsigned long *max_high)
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{
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*max_low = PFN_DOWN(memblock_get_current_limit());
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*min = PFN_UP(memblock_start_of_DRAM());
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*max_high = PFN_DOWN(memblock_end_of_DRAM());
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}
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#ifdef CONFIG_ZONE_DMA
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phys_addr_t arm_dma_zone_size __read_mostly;
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EXPORT_SYMBOL(arm_dma_zone_size);
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/*
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* The DMA mask corresponding to the maximum bus address allocatable
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* using GFP_DMA. The default here places no restriction on DMA
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* allocations. This must be the smallest DMA mask in the system,
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* so a successful GFP_DMA allocation will always satisfy this.
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*/
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phys_addr_t arm_dma_limit;
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unsigned long arm_dma_pfn_limit;
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static void __init arm_adjust_dma_zone(unsigned long *size, unsigned long *hole,
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unsigned long dma_size)
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{
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if (size[0] <= dma_size)
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return;
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size[ZONE_NORMAL] = size[0] - dma_size;
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size[ZONE_DMA] = dma_size;
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hole[ZONE_NORMAL] = hole[0];
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hole[ZONE_DMA] = 0;
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}
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#endif
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void __init setup_dma_zone(const struct machine_desc *mdesc)
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{
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#ifdef CONFIG_ZONE_DMA
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if (mdesc->dma_zone_size) {
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arm_dma_zone_size = mdesc->dma_zone_size;
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arm_dma_limit = PHYS_OFFSET + arm_dma_zone_size - 1;
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} else
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arm_dma_limit = 0xffffffff;
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arm_dma_pfn_limit = arm_dma_limit >> PAGE_SHIFT;
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#endif
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}
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static void __init zone_sizes_init(unsigned long min, unsigned long max_low,
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unsigned long max_high)
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{
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unsigned long zone_size[MAX_NR_ZONES], zhole_size[MAX_NR_ZONES];
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struct memblock_region *reg;
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/*
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* initialise the zones.
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*/
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memset(zone_size, 0, sizeof(zone_size));
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/*
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* The memory size has already been determined. If we need
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* to do anything fancy with the allocation of this memory
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* to the zones, now is the time to do it.
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*/
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zone_size[0] = max_low - min;
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#ifdef CONFIG_HIGHMEM
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zone_size[ZONE_HIGHMEM] = max_high - max_low;
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#endif
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/*
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* Calculate the size of the holes.
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* holes = node_size - sum(bank_sizes)
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*/
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memcpy(zhole_size, zone_size, sizeof(zhole_size));
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for_each_memblock(memory, reg) {
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unsigned long start = memblock_region_memory_base_pfn(reg);
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unsigned long end = memblock_region_memory_end_pfn(reg);
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if (start < max_low) {
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unsigned long low_end = min(end, max_low);
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zhole_size[0] -= low_end - start;
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}
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#ifdef CONFIG_HIGHMEM
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if (end > max_low) {
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unsigned long high_start = max(start, max_low);
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zhole_size[ZONE_HIGHMEM] -= end - high_start;
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}
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#endif
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}
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#ifdef CONFIG_ZONE_DMA
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/*
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* Adjust the sizes according to any special requirements for
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* this machine type.
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*/
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if (arm_dma_zone_size)
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arm_adjust_dma_zone(zone_size, zhole_size,
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arm_dma_zone_size >> PAGE_SHIFT);
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#endif
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free_area_init_node(0, zone_size, min, zhole_size);
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}
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#ifdef CONFIG_HAVE_ARCH_PFN_VALID
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int pfn_valid(unsigned long pfn)
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{
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return memblock_is_map_memory(__pfn_to_phys(pfn));
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}
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EXPORT_SYMBOL(pfn_valid);
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#endif
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#ifndef CONFIG_SPARSEMEM
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static void __init arm_memory_present(void)
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{
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}
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#else
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static void __init arm_memory_present(void)
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{
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struct memblock_region *reg;
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for_each_memblock(memory, reg)
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memory_present(0, memblock_region_memory_base_pfn(reg),
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memblock_region_memory_end_pfn(reg));
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}
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#endif
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static bool arm_memblock_steal_permitted = true;
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phys_addr_t __init arm_memblock_steal(phys_addr_t size, phys_addr_t align)
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{
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phys_addr_t phys;
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BUG_ON(!arm_memblock_steal_permitted);
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phys = memblock_alloc_base(size, align, MEMBLOCK_ALLOC_ANYWHERE);
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memblock_free(phys, size);
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memblock_remove(phys, size);
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return phys;
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}
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static void __init arm_initrd_init(void)
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{
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#ifdef CONFIG_BLK_DEV_INITRD
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phys_addr_t start;
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unsigned long size;
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/* FDT scan will populate initrd_start */
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if (initrd_start && !phys_initrd_size) {
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phys_initrd_start = __virt_to_phys(initrd_start);
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phys_initrd_size = initrd_end - initrd_start;
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}
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initrd_start = initrd_end = 0;
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if (!phys_initrd_size)
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return;
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/*
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* Round the memory region to page boundaries as per free_initrd_mem()
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* This allows us to detect whether the pages overlapping the initrd
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* are in use, but more importantly, reserves the entire set of pages
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* as we don't want these pages allocated for other purposes.
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*/
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start = round_down(phys_initrd_start, PAGE_SIZE);
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size = phys_initrd_size + (phys_initrd_start - start);
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size = round_up(size, PAGE_SIZE);
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if (!memblock_is_region_memory(start, size)) {
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pr_err("INITRD: 0x%08llx+0x%08lx is not a memory region - disabling initrd\n",
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(u64)start, size);
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return;
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}
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if (memblock_is_region_reserved(start, size)) {
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pr_err("INITRD: 0x%08llx+0x%08lx overlaps in-use memory region - disabling initrd\n",
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(u64)start, size);
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return;
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}
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memblock_reserve(start, size);
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/* Now convert initrd to virtual addresses */
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initrd_start = __phys_to_virt(phys_initrd_start);
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initrd_end = initrd_start + phys_initrd_size;
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#endif
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}
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void __init arm_memblock_init(const struct machine_desc *mdesc)
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{
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/* Register the kernel text, kernel data and initrd with memblock. */
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memblock_reserve(__pa(KERNEL_START), KERNEL_END - KERNEL_START);
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arm_initrd_init();
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arm_mm_memblock_reserve();
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/* reserve any platform specific memblock areas */
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if (mdesc->reserve)
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mdesc->reserve();
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early_init_fdt_reserve_self();
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early_init_fdt_scan_reserved_mem();
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/* reserve memory for DMA contiguous allocations */
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dma_contiguous_reserve(arm_dma_limit);
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arm_memblock_steal_permitted = false;
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memblock_dump_all();
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}
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void __init bootmem_init(void)
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{
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unsigned long min, max_low, max_high;
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memblock_allow_resize();
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max_low = max_high = 0;
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find_limits(&min, &max_low, &max_high);
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early_memtest((phys_addr_t)min << PAGE_SHIFT,
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(phys_addr_t)max_low << PAGE_SHIFT);
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/*
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* Sparsemem tries to allocate bootmem in memory_present(),
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* so must be done after the fixed reservations
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*/
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arm_memory_present();
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/*
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* sparse_init() needs the bootmem allocator up and running.
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*/
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sparse_init();
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/*
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* Now free the memory - free_area_init_node needs
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* the sparse mem_map arrays initialized by sparse_init()
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* for memmap_init_zone(), otherwise all PFNs are invalid.
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*/
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zone_sizes_init(min, max_low, max_high);
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/*
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* This doesn't seem to be used by the Linux memory manager any
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* more, but is used by ll_rw_block. If we can get rid of it, we
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* also get rid of some of the stuff above as well.
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*/
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min_low_pfn = min;
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max_low_pfn = max_low;
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max_pfn = max_high;
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}
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/*
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* Poison init memory with an undefined instruction (ARM) or a branch to an
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* undefined instruction (Thumb).
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*/
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static inline void poison_init_mem(void *s, size_t count)
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{
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u32 *p = (u32 *)s;
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for (; count != 0; count -= 4)
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*p++ = 0xe7fddef0;
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}
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static inline void
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free_memmap(unsigned long start_pfn, unsigned long end_pfn)
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{
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struct page *start_pg, *end_pg;
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phys_addr_t pg, pgend;
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/*
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* Convert start_pfn/end_pfn to a struct page pointer.
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*/
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start_pg = pfn_to_page(start_pfn - 1) + 1;
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end_pg = pfn_to_page(end_pfn - 1) + 1;
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/*
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* Convert to physical addresses, and
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* round start upwards and end downwards.
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*/
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pg = PAGE_ALIGN(__pa(start_pg));
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pgend = __pa(end_pg) & PAGE_MASK;
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/*
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* If there are free pages between these,
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* free the section of the memmap array.
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*/
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if (pg < pgend)
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memblock_free_early(pg, pgend - pg);
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}
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/*
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* The mem_map array can get very big. Free the unused area of the memory map.
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*/
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static void __init free_unused_memmap(void)
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{
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unsigned long start, prev_end = 0;
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struct memblock_region *reg;
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/*
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* This relies on each bank being in address order.
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* The banks are sorted previously in bootmem_init().
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*/
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for_each_memblock(memory, reg) {
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start = memblock_region_memory_base_pfn(reg);
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#ifdef CONFIG_SPARSEMEM
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/*
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* Take care not to free memmap entries that don't exist
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* due to SPARSEMEM sections which aren't present.
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*/
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start = min(start,
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ALIGN(prev_end, PAGES_PER_SECTION));
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#else
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/*
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* Align down here since the VM subsystem insists that the
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* memmap entries are valid from the bank start aligned to
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* MAX_ORDER_NR_PAGES.
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*/
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start = round_down(start, MAX_ORDER_NR_PAGES);
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#endif
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/*
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* If we had a previous bank, and there is a space
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* between the current bank and the previous, free it.
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*/
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if (prev_end && prev_end < start)
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free_memmap(prev_end, start);
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/*
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* Align up here since the VM subsystem insists that the
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* memmap entries are valid from the bank end aligned to
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* MAX_ORDER_NR_PAGES.
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*/
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prev_end = ALIGN(memblock_region_memory_end_pfn(reg),
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MAX_ORDER_NR_PAGES);
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}
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#ifdef CONFIG_SPARSEMEM
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if (!IS_ALIGNED(prev_end, PAGES_PER_SECTION))
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free_memmap(prev_end,
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ALIGN(prev_end, PAGES_PER_SECTION));
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#endif
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}
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#ifdef CONFIG_HIGHMEM
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static inline void free_area_high(unsigned long pfn, unsigned long end)
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{
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for (; pfn < end; pfn++)
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free_highmem_page(pfn_to_page(pfn));
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}
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#endif
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static void __init free_highpages(void)
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{
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#ifdef CONFIG_HIGHMEM
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unsigned long max_low = max_low_pfn;
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struct memblock_region *mem, *res;
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/* set highmem page free */
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for_each_memblock(memory, mem) {
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unsigned long start = memblock_region_memory_base_pfn(mem);
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unsigned long end = memblock_region_memory_end_pfn(mem);
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/* Ignore complete lowmem entries */
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if (end <= max_low)
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continue;
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if (memblock_is_nomap(mem))
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continue;
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/* Truncate partial highmem entries */
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if (start < max_low)
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start = max_low;
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/* Find and exclude any reserved regions */
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for_each_memblock(reserved, res) {
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unsigned long res_start, res_end;
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res_start = memblock_region_reserved_base_pfn(res);
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res_end = memblock_region_reserved_end_pfn(res);
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if (res_end < start)
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continue;
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if (res_start < start)
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res_start = start;
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if (res_start > end)
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res_start = end;
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if (res_end > end)
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res_end = end;
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if (res_start != start)
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free_area_high(start, res_start);
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start = res_end;
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if (start == end)
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break;
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}
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/* And now free anything which remains */
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if (start < end)
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free_area_high(start, end);
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}
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#endif
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}
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/*
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* mem_init() marks the free areas in the mem_map and tells us how much
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* memory is free. This is done after various parts of the system have
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* claimed their memory after the kernel image.
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*/
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void __init mem_init(void)
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{
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#ifdef CONFIG_HAVE_TCM
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/* These pointers are filled in on TCM detection */
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extern u32 dtcm_end;
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extern u32 itcm_end;
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#endif
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set_max_mapnr(pfn_to_page(max_pfn) - mem_map);
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/* this will put all unused low memory onto the freelists */
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free_unused_memmap();
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free_all_bootmem();
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#ifdef CONFIG_SA1111
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/* now that our DMA memory is actually so designated, we can free it */
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free_reserved_area(__va(PHYS_OFFSET), swapper_pg_dir, -1, NULL);
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#endif
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free_highpages();
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mem_init_print_info(NULL);
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#define MLK(b, t) b, t, ((t) - (b)) >> 10
|
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#define MLM(b, t) b, t, ((t) - (b)) >> 20
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#define MLK_ROUNDUP(b, t) b, t, DIV_ROUND_UP(((t) - (b)), SZ_1K)
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|
|
|
pr_notice("Virtual kernel memory layout:\n"
|
|
" vector : 0x%08lx - 0x%08lx (%4ld kB)\n"
|
|
#ifdef CONFIG_HAVE_TCM
|
|
" DTCM : 0x%08lx - 0x%08lx (%4ld kB)\n"
|
|
" ITCM : 0x%08lx - 0x%08lx (%4ld kB)\n"
|
|
#endif
|
|
" fixmap : 0x%08lx - 0x%08lx (%4ld kB)\n"
|
|
" vmalloc : 0x%08lx - 0x%08lx (%4ld MB)\n"
|
|
" lowmem : 0x%08lx - 0x%08lx (%4ld MB)\n"
|
|
#ifdef CONFIG_HIGHMEM
|
|
" pkmap : 0x%08lx - 0x%08lx (%4ld MB)\n"
|
|
#endif
|
|
#ifdef CONFIG_MODULES
|
|
" modules : 0x%08lx - 0x%08lx (%4ld MB)\n"
|
|
#endif
|
|
" .text : 0x%p" " - 0x%p" " (%4td kB)\n"
|
|
" .init : 0x%p" " - 0x%p" " (%4td kB)\n"
|
|
" .data : 0x%p" " - 0x%p" " (%4td kB)\n"
|
|
" .bss : 0x%p" " - 0x%p" " (%4td kB)\n",
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|
|
|
MLK(VECTORS_BASE, VECTORS_BASE + PAGE_SIZE),
|
|
#ifdef CONFIG_HAVE_TCM
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|
MLK(DTCM_OFFSET, (unsigned long) dtcm_end),
|
|
MLK(ITCM_OFFSET, (unsigned long) itcm_end),
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|
#endif
|
|
MLK(FIXADDR_START, FIXADDR_END),
|
|
MLM(VMALLOC_START, VMALLOC_END),
|
|
MLM(PAGE_OFFSET, (unsigned long)high_memory),
|
|
#ifdef CONFIG_HIGHMEM
|
|
MLM(PKMAP_BASE, (PKMAP_BASE) + (LAST_PKMAP) *
|
|
(PAGE_SIZE)),
|
|
#endif
|
|
#ifdef CONFIG_MODULES
|
|
MLM(MODULES_VADDR, MODULES_END),
|
|
#endif
|
|
|
|
MLK_ROUNDUP(_text, _etext),
|
|
MLK_ROUNDUP(__init_begin, __init_end),
|
|
MLK_ROUNDUP(_sdata, _edata),
|
|
MLK_ROUNDUP(__bss_start, __bss_stop));
|
|
|
|
#undef MLK
|
|
#undef MLM
|
|
#undef MLK_ROUNDUP
|
|
|
|
/*
|
|
* Check boundaries twice: Some fundamental inconsistencies can
|
|
* be detected at build time already.
|
|
*/
|
|
#ifdef CONFIG_MMU
|
|
BUILD_BUG_ON(TASK_SIZE > MODULES_VADDR);
|
|
BUG_ON(TASK_SIZE > MODULES_VADDR);
|
|
#endif
|
|
|
|
#ifdef CONFIG_HIGHMEM
|
|
BUILD_BUG_ON(PKMAP_BASE + LAST_PKMAP * PAGE_SIZE > PAGE_OFFSET);
|
|
BUG_ON(PKMAP_BASE + LAST_PKMAP * PAGE_SIZE > PAGE_OFFSET);
|
|
#endif
|
|
}
|
|
|
|
#ifdef CONFIG_STRICT_KERNEL_RWX
|
|
struct section_perm {
|
|
const char *name;
|
|
unsigned long start;
|
|
unsigned long end;
|
|
pmdval_t mask;
|
|
pmdval_t prot;
|
|
pmdval_t clear;
|
|
};
|
|
|
|
/* First section-aligned location at or after __start_rodata. */
|
|
extern char __start_rodata_section_aligned[];
|
|
|
|
static struct section_perm nx_perms[] = {
|
|
/* Make pages tables, etc before _stext RW (set NX). */
|
|
{
|
|
.name = "pre-text NX",
|
|
.start = PAGE_OFFSET,
|
|
.end = (unsigned long)_stext,
|
|
.mask = ~PMD_SECT_XN,
|
|
.prot = PMD_SECT_XN,
|
|
},
|
|
/* Make init RW (set NX). */
|
|
{
|
|
.name = "init NX",
|
|
.start = (unsigned long)__init_begin,
|
|
.end = (unsigned long)_sdata,
|
|
.mask = ~PMD_SECT_XN,
|
|
.prot = PMD_SECT_XN,
|
|
},
|
|
/* Make rodata NX (set RO in ro_perms below). */
|
|
{
|
|
.name = "rodata NX",
|
|
.start = (unsigned long)__start_rodata_section_aligned,
|
|
.end = (unsigned long)__init_begin,
|
|
.mask = ~PMD_SECT_XN,
|
|
.prot = PMD_SECT_XN,
|
|
},
|
|
};
|
|
|
|
static struct section_perm ro_perms[] = {
|
|
/* Make kernel code and rodata RX (set RO). */
|
|
{
|
|
.name = "text/rodata RO",
|
|
.start = (unsigned long)_stext,
|
|
.end = (unsigned long)__init_begin,
|
|
#ifdef CONFIG_ARM_LPAE
|
|
.mask = ~(L_PMD_SECT_RDONLY | PMD_SECT_AP2),
|
|
.prot = L_PMD_SECT_RDONLY | PMD_SECT_AP2,
|
|
#else
|
|
.mask = ~(PMD_SECT_APX | PMD_SECT_AP_WRITE),
|
|
.prot = PMD_SECT_APX | PMD_SECT_AP_WRITE,
|
|
.clear = PMD_SECT_AP_WRITE,
|
|
#endif
|
|
},
|
|
};
|
|
|
|
/*
|
|
* Updates section permissions only for the current mm (sections are
|
|
* copied into each mm). During startup, this is the init_mm. Is only
|
|
* safe to be called with preemption disabled, as under stop_machine().
|
|
*/
|
|
static inline void section_update(unsigned long addr, pmdval_t mask,
|
|
pmdval_t prot, struct mm_struct *mm)
|
|
{
|
|
pmd_t *pmd;
|
|
|
|
pmd = pmd_offset(pud_offset(pgd_offset(mm, addr), addr), addr);
|
|
|
|
#ifdef CONFIG_ARM_LPAE
|
|
pmd[0] = __pmd((pmd_val(pmd[0]) & mask) | prot);
|
|
#else
|
|
if (addr & SECTION_SIZE)
|
|
pmd[1] = __pmd((pmd_val(pmd[1]) & mask) | prot);
|
|
else
|
|
pmd[0] = __pmd((pmd_val(pmd[0]) & mask) | prot);
|
|
#endif
|
|
flush_pmd_entry(pmd);
|
|
local_flush_tlb_kernel_range(addr, addr + SECTION_SIZE);
|
|
}
|
|
|
|
/* Make sure extended page tables are in use. */
|
|
static inline bool arch_has_strict_perms(void)
|
|
{
|
|
if (cpu_architecture() < CPU_ARCH_ARMv6)
|
|
return false;
|
|
|
|
return !!(get_cr() & CR_XP);
|
|
}
|
|
|
|
void set_section_perms(struct section_perm *perms, int n, bool set,
|
|
struct mm_struct *mm)
|
|
{
|
|
size_t i;
|
|
unsigned long addr;
|
|
|
|
if (!arch_has_strict_perms())
|
|
return;
|
|
|
|
for (i = 0; i < n; i++) {
|
|
if (!IS_ALIGNED(perms[i].start, SECTION_SIZE) ||
|
|
!IS_ALIGNED(perms[i].end, SECTION_SIZE)) {
|
|
pr_err("BUG: %s section %lx-%lx not aligned to %lx\n",
|
|
perms[i].name, perms[i].start, perms[i].end,
|
|
SECTION_SIZE);
|
|
continue;
|
|
}
|
|
|
|
for (addr = perms[i].start;
|
|
addr < perms[i].end;
|
|
addr += SECTION_SIZE)
|
|
section_update(addr, perms[i].mask,
|
|
set ? perms[i].prot : perms[i].clear, mm);
|
|
}
|
|
|
|
}
|
|
|
|
/**
|
|
* update_sections_early intended to be called only through stop_machine
|
|
* framework and executed by only one CPU while all other CPUs will spin and
|
|
* wait, so no locking is required in this function.
|
|
*/
|
|
static void update_sections_early(struct section_perm perms[], int n)
|
|
{
|
|
struct task_struct *t, *s;
|
|
|
|
for_each_process(t) {
|
|
if (t->flags & PF_KTHREAD)
|
|
continue;
|
|
for_each_thread(t, s)
|
|
set_section_perms(perms, n, true, s->mm);
|
|
}
|
|
set_section_perms(perms, n, true, current->active_mm);
|
|
set_section_perms(perms, n, true, &init_mm);
|
|
}
|
|
|
|
static int __fix_kernmem_perms(void *unused)
|
|
{
|
|
update_sections_early(nx_perms, ARRAY_SIZE(nx_perms));
|
|
return 0;
|
|
}
|
|
|
|
static void fix_kernmem_perms(void)
|
|
{
|
|
stop_machine(__fix_kernmem_perms, NULL, NULL);
|
|
}
|
|
|
|
static int __mark_rodata_ro(void *unused)
|
|
{
|
|
update_sections_early(ro_perms, ARRAY_SIZE(ro_perms));
|
|
return 0;
|
|
}
|
|
|
|
void mark_rodata_ro(void)
|
|
{
|
|
stop_machine(__mark_rodata_ro, NULL, NULL);
|
|
debug_checkwx();
|
|
}
|
|
|
|
void set_kernel_text_rw(void)
|
|
{
|
|
set_section_perms(ro_perms, ARRAY_SIZE(ro_perms), false,
|
|
current->active_mm);
|
|
}
|
|
|
|
void set_kernel_text_ro(void)
|
|
{
|
|
set_section_perms(ro_perms, ARRAY_SIZE(ro_perms), true,
|
|
current->active_mm);
|
|
}
|
|
|
|
#else
|
|
static inline void fix_kernmem_perms(void) { }
|
|
#endif /* CONFIG_STRICT_KERNEL_RWX */
|
|
|
|
void free_tcmmem(void)
|
|
{
|
|
#ifdef CONFIG_HAVE_TCM
|
|
extern char __tcm_start, __tcm_end;
|
|
|
|
poison_init_mem(&__tcm_start, &__tcm_end - &__tcm_start);
|
|
free_reserved_area(&__tcm_start, &__tcm_end, -1, "TCM link");
|
|
#endif
|
|
}
|
|
|
|
void free_initmem(void)
|
|
{
|
|
fix_kernmem_perms();
|
|
free_tcmmem();
|
|
|
|
poison_init_mem(__init_begin, __init_end - __init_begin);
|
|
if (!machine_is_integrator() && !machine_is_cintegrator())
|
|
free_initmem_default(-1);
|
|
}
|
|
|
|
#ifdef CONFIG_BLK_DEV_INITRD
|
|
|
|
static int keep_initrd;
|
|
|
|
void free_initrd_mem(unsigned long start, unsigned long end)
|
|
{
|
|
if (!keep_initrd) {
|
|
if (start == initrd_start)
|
|
start = round_down(start, PAGE_SIZE);
|
|
if (end == initrd_end)
|
|
end = round_up(end, PAGE_SIZE);
|
|
|
|
poison_init_mem((void *)start, PAGE_ALIGN(end) - start);
|
|
free_reserved_area((void *)start, (void *)end, -1, "initrd");
|
|
}
|
|
}
|
|
|
|
static int __init keepinitrd_setup(char *__unused)
|
|
{
|
|
keep_initrd = 1;
|
|
return 1;
|
|
}
|
|
|
|
__setup("keepinitrd", keepinitrd_setup);
|
|
#endif
|