cregit-Linux how code gets into the kernel

Release 4.11 arch/arm/mm/copypage-v6.c

Directory: arch/arm/mm
/*
 *  linux/arch/arm/mm/copypage-v6.c
 *
 *  Copyright (C) 2002 Deep Blue Solutions Ltd, All Rights Reserved.
 *
 * 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/init.h>
#include <linux/spinlock.h>
#include <linux/mm.h>
#include <linux/highmem.h>

#include <asm/pgtable.h>
#include <asm/shmparam.h>
#include <asm/tlbflush.h>
#include <asm/cacheflush.h>
#include <asm/cachetype.h>

#include "mm.h"

#if SHMLBA > 16384
#error FIX ME
#endif

static DEFINE_RAW_SPINLOCK(v6_lock);

/*
 * Copy the user page.  No aliasing to deal with so we can just
 * attack the kernel's existing mapping of these pages.
 */

static void v6_copy_user_highpage_nonaliasing(struct page *to, struct page *from, unsigned long vaddr, struct vm_area_struct *vma) { void *kto, *kfrom; kfrom = kmap_atomic(from); kto = kmap_atomic(to); copy_page(kto, kfrom); kunmap_atomic(kto); kunmap_atomic(kfrom); }

Contributors

PersonTokensPropCommitsCommitProp
Russell King63100.00%4100.00%
Total63100.00%4100.00%

/* * Clear the user page. No aliasing to deal with so we can just * attack the kernel's existing mapping of this page. */
static void v6_clear_user_highpage_nonaliasing(struct page *page, unsigned long vaddr) { void *kaddr = kmap_atomic(page); clear_page(kaddr); kunmap_atomic(kaddr); }

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Russell King34100.00%3100.00%
Total34100.00%3100.00%

/* * Discard data in the kernel mapping for the new page. * FIXME: needs this MCRR to be supported. */
static void discard_old_kernel_data(void *kto) { __asm__("mcrr p15, 0, %1, %0, c6 @ 0xec401f06" : : "r" (kto), "r" ((unsigned long)kto + PAGE_SIZE - 1) : "cc"); }

Contributors

PersonTokensPropCommitsCommitProp
Russell King1090.91%375.00%
Jungseung Lee19.09%125.00%
Total11100.00%4100.00%

/* * Copy the page, taking account of the cache colour. */
static void v6_copy_user_highpage_aliasing(struct page *to, struct page *from, unsigned long vaddr, struct vm_area_struct *vma) { unsigned int offset = CACHE_COLOUR(vaddr); unsigned long kfrom, kto; if (!test_and_set_bit(PG_dcache_clean, &from->flags)) __flush_dcache_page(page_mapping(from), from); /* FIXME: not highmem safe */ discard_old_kernel_data(page_address(to)); /* * Now copy the page using the same cache colour as the * pages ultimate destination. */ raw_spin_lock(&v6_lock); kfrom = COPYPAGE_V6_FROM + (offset << PAGE_SHIFT); kto = COPYPAGE_V6_TO + (offset << PAGE_SHIFT); set_top_pte(kfrom, mk_pte(from, PAGE_KERNEL)); set_top_pte(kto, mk_pte(to, PAGE_KERNEL)); copy_page((void *)kto, (void *)kfrom); raw_spin_unlock(&v6_lock); }

Contributors

PersonTokensPropCommitsCommitProp
Russell King12083.33%975.00%
Richard Purdie1913.19%18.33%
Catalin Marinas32.08%18.33%
Thomas Gleixner21.39%18.33%
Total144100.00%12100.00%

/* * Clear the user page. We need to deal with the aliasing issues, * so remap the kernel page into the same cache colour as the user * page. */
static void v6_clear_user_highpage_aliasing(struct page *page, unsigned long vaddr) { unsigned long to = COPYPAGE_V6_TO + (CACHE_COLOUR(vaddr) << PAGE_SHIFT); /* FIXME: not highmem safe */ discard_old_kernel_data(page_address(page)); /* * Now clear the page using the same cache colour as * the pages ultimate destination. */ raw_spin_lock(&v6_lock); set_top_pte(to, mk_pte(page, PAGE_KERNEL)); clear_page((void *)to); raw_spin_unlock(&v6_lock); }

Contributors

PersonTokensPropCommitsCommitProp
Russell King7197.26%787.50%
Thomas Gleixner22.74%112.50%
Total73100.00%8100.00%

struct cpu_user_fns v6_user_fns __initdata = { .cpu_clear_user_highpage = v6_clear_user_highpage_nonaliasing, .cpu_copy_user_highpage = v6_copy_user_highpage_nonaliasing, };
static int __init v6_userpage_init(void) { if (cache_is_vipt_aliasing()) { cpu_user.cpu_clear_user_highpage = v6_clear_user_highpage_aliasing; cpu_user.cpu_copy_user_highpage = v6_copy_user_highpage_aliasing; } return 0; }

Contributors

PersonTokensPropCommitsCommitProp
Russell King31100.00%5100.00%
Total31100.00%5100.00%

core_initcall(v6_userpage_init);

Overall Contributors

PersonTokensPropCommitsCommitProp
Russell King39692.09%1470.00%
Richard Purdie194.42%15.00%
Thomas Gleixner81.86%210.00%
Catalin Marinas61.40%210.00%
Jungseung Lee10.23%15.00%
Total430100.00%20100.00%
Directory: arch/arm/mm
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