bda8960281
commit c091fb6ae059cda563b2a4d93fdbc548ef34e1d6 upstream. The trampoline code has a data page that holds the address of the vectors, which is unmapped when running in user-space. This ensures that with CONFIG_RANDOMIZE_BASE, the randomised address of the kernel can't be discovered until after the kernel has been mapped. If the trampoline text page is extended to include multiple sets of vectors, it will be larger than a single page, making it tricky to find the data page without knowing the size of the trampoline text pages, which will vary with PAGE_SIZE. Move the data page to appear before the text page. This allows the data page to be found without knowing the size of the trampoline text pages. 'tramp_vectors' is used to refer to the beginning of the .entry.tramp.text section, do that explicitly. Reviewed-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: James Morse <james.morse@arm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
112 lines
3.0 KiB
C
112 lines
3.0 KiB
C
/*
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* fixmap.h: compile-time virtual memory allocation
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*
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* This file is subject to the terms and conditions of the GNU General Public
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* License. See the file "COPYING" in the main directory of this archive
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* for more details.
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*
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* Copyright (C) 1998 Ingo Molnar
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* Copyright (C) 2013 Mark Salter <msalter@redhat.com>
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*
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* Adapted from arch/x86 version.
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*
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*/
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#ifndef _ASM_ARM64_FIXMAP_H
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#define _ASM_ARM64_FIXMAP_H
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#ifndef __ASSEMBLY__
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#include <linux/kernel.h>
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#include <linux/sizes.h>
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#include <asm/boot.h>
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#include <asm/page.h>
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#include <asm/pgtable-prot.h>
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/*
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* Here we define all the compile-time 'special' virtual
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* addresses. The point is to have a constant address at
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* compile time, but to set the physical address only
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* in the boot process.
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*
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* Each enum increment in these 'compile-time allocated'
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* memory buffers is page-sized. Use set_fixmap(idx,phys)
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* to associate physical memory with a fixmap index.
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*/
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enum fixed_addresses {
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FIX_HOLE,
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/*
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* Reserve a virtual window for the FDT that is 2 MB larger than the
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* maximum supported size, and put it at the top of the fixmap region.
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* The additional space ensures that any FDT that does not exceed
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* MAX_FDT_SIZE can be mapped regardless of whether it crosses any
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* 2 MB alignment boundaries.
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*
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* Keep this at the top so it remains 2 MB aligned.
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*/
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#define FIX_FDT_SIZE (MAX_FDT_SIZE + SZ_2M)
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FIX_FDT_END,
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FIX_FDT = FIX_FDT_END + FIX_FDT_SIZE / PAGE_SIZE - 1,
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FIX_EARLYCON_MEM_BASE,
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FIX_TEXT_POKE0,
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#ifdef CONFIG_ACPI_APEI_GHES
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/* Used for GHES mapping from assorted contexts */
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FIX_APEI_GHES_IRQ,
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FIX_APEI_GHES_SEA,
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#ifdef CONFIG_ARM_SDE_INTERFACE
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FIX_APEI_GHES_SDEI_NORMAL,
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FIX_APEI_GHES_SDEI_CRITICAL,
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#endif
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#endif /* CONFIG_ACPI_APEI_GHES */
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#ifdef CONFIG_UNMAP_KERNEL_AT_EL0
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FIX_ENTRY_TRAMP_TEXT,
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FIX_ENTRY_TRAMP_DATA,
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#define TRAMP_VALIAS (__fix_to_virt(FIX_ENTRY_TRAMP_TEXT))
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#endif /* CONFIG_UNMAP_KERNEL_AT_EL0 */
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__end_of_permanent_fixed_addresses,
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/*
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* Temporary boot-time mappings, used by early_ioremap(),
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* before ioremap() is functional.
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*/
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#define NR_FIX_BTMAPS (SZ_256K / PAGE_SIZE)
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#define FIX_BTMAPS_SLOTS 7
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#define TOTAL_FIX_BTMAPS (NR_FIX_BTMAPS * FIX_BTMAPS_SLOTS)
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FIX_BTMAP_END = __end_of_permanent_fixed_addresses,
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FIX_BTMAP_BEGIN = FIX_BTMAP_END + TOTAL_FIX_BTMAPS - 1,
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/*
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* Used for kernel page table creation, so unmapped memory may be used
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* for tables.
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*/
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FIX_PTE,
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FIX_PMD,
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FIX_PUD,
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FIX_PGD,
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__end_of_fixed_addresses
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};
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#define FIXADDR_SIZE (__end_of_permanent_fixed_addresses << PAGE_SHIFT)
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#define FIXADDR_START (FIXADDR_TOP - FIXADDR_SIZE)
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#define FIXMAP_PAGE_IO __pgprot(PROT_DEVICE_nGnRE)
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void __init early_fixmap_init(void);
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#define __early_set_fixmap __set_fixmap
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#define __late_set_fixmap __set_fixmap
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#define __late_clear_fixmap(idx) __set_fixmap((idx), 0, FIXMAP_PAGE_CLEAR)
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extern void __set_fixmap(enum fixed_addresses idx, phys_addr_t phys, pgprot_t prot);
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#include <asm-generic/fixmap.h>
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#endif /* !__ASSEMBLY__ */
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#endif /* _ASM_ARM64_FIXMAP_H */
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