linux/arch/arm64/include/asm/fixmap.h
Laura Abbott 2f896d5866 arm64: use fixmap for text patching
When kernel text is marked as read only, it cannot be modified directly.
Use a fixmap to modify the text instead in a similar manner to
x86 and arm.

Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Tested-by: Kees Cook <keescook@chromium.org>
Tested-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Laura Abbott <lauraa@codeaurora.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2015-01-22 11:50:56 +00:00

71 lines
1.8 KiB
C

/*
* fixmap.h: compile-time virtual memory allocation
*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file "COPYING" in the main directory of this archive
* for more details.
*
* Copyright (C) 1998 Ingo Molnar
* Copyright (C) 2013 Mark Salter <msalter@redhat.com>
*
* Adapted from arch/x86_64 version.
*
*/
#ifndef _ASM_ARM64_FIXMAP_H
#define _ASM_ARM64_FIXMAP_H
#ifndef __ASSEMBLY__
#include <linux/kernel.h>
#include <asm/page.h>
/*
* Here we define all the compile-time 'special' virtual
* addresses. The point is to have a constant address at
* compile time, but to set the physical address only
* in the boot process.
*
* These 'compile-time allocated' memory buffers are
* page-sized. Use set_fixmap(idx,phys) to associate
* physical memory with fixmap indices.
*
*/
enum fixed_addresses {
FIX_HOLE,
FIX_EARLYCON_MEM_BASE,
__end_of_permanent_fixed_addresses,
/*
* Temporary boot-time mappings, used by early_ioremap(),
* before ioremap() is functional.
*/
#ifdef CONFIG_ARM64_64K_PAGES
#define NR_FIX_BTMAPS 4
#else
#define NR_FIX_BTMAPS 64
#endif
#define FIX_BTMAPS_SLOTS 7
#define TOTAL_FIX_BTMAPS (NR_FIX_BTMAPS * FIX_BTMAPS_SLOTS)
FIX_BTMAP_END = __end_of_permanent_fixed_addresses,
FIX_BTMAP_BEGIN = FIX_BTMAP_END + TOTAL_FIX_BTMAPS - 1,
FIX_TEXT_POKE0,
__end_of_fixed_addresses
};
#define FIXADDR_SIZE (__end_of_permanent_fixed_addresses << PAGE_SHIFT)
#define FIXADDR_START (FIXADDR_TOP - FIXADDR_SIZE)
#define FIXMAP_PAGE_IO __pgprot(PROT_DEVICE_nGnRE)
void __init early_fixmap_init(void);
#define __early_set_fixmap __set_fixmap
extern void __set_fixmap(enum fixed_addresses idx, phys_addr_t phys, pgprot_t prot);
#include <asm-generic/fixmap.h>
#endif /* !__ASSEMBLY__ */
#endif /* _ASM_ARM64_FIXMAP_H */