d8aa712c30
Commitf6f91b0d9f(ARM: allow kuser helpers to be removed from the vector page) required two pages for the vectors code. Although the code setting up the initial page tables was updated, the code which allocates page tables for new processes wasn't, neither was the code which tears down the mappings. Fix this. Fixes:f6f91b0d9f("ARM: allow kuser helpers to be removed from the vector page") Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk> Cc: <stable@vger.kernel.org>
161 lines
3.3 KiB
C
161 lines
3.3 KiB
C
/*
|
|
* linux/arch/arm/mm/pgd.c
|
|
*
|
|
* Copyright (C) 1998-2005 Russell King
|
|
*
|
|
* 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/mm.h>
|
|
#include <linux/gfp.h>
|
|
#include <linux/highmem.h>
|
|
#include <linux/slab.h>
|
|
|
|
#include <asm/cp15.h>
|
|
#include <asm/pgalloc.h>
|
|
#include <asm/page.h>
|
|
#include <asm/tlbflush.h>
|
|
|
|
#include "mm.h"
|
|
|
|
#ifdef CONFIG_ARM_LPAE
|
|
#define __pgd_alloc() kmalloc(PTRS_PER_PGD * sizeof(pgd_t), GFP_KERNEL)
|
|
#define __pgd_free(pgd) kfree(pgd)
|
|
#else
|
|
#define __pgd_alloc() (pgd_t *)__get_free_pages(GFP_KERNEL, 2)
|
|
#define __pgd_free(pgd) free_pages((unsigned long)pgd, 2)
|
|
#endif
|
|
|
|
/*
|
|
* need to get a 16k page for level 1
|
|
*/
|
|
pgd_t *pgd_alloc(struct mm_struct *mm)
|
|
{
|
|
pgd_t *new_pgd, *init_pgd;
|
|
pud_t *new_pud, *init_pud;
|
|
pmd_t *new_pmd, *init_pmd;
|
|
pte_t *new_pte, *init_pte;
|
|
|
|
new_pgd = __pgd_alloc();
|
|
if (!new_pgd)
|
|
goto no_pgd;
|
|
|
|
memset(new_pgd, 0, USER_PTRS_PER_PGD * sizeof(pgd_t));
|
|
|
|
/*
|
|
* Copy over the kernel and IO PGD entries
|
|
*/
|
|
init_pgd = pgd_offset_k(0);
|
|
memcpy(new_pgd + USER_PTRS_PER_PGD, init_pgd + USER_PTRS_PER_PGD,
|
|
(PTRS_PER_PGD - USER_PTRS_PER_PGD) * sizeof(pgd_t));
|
|
|
|
clean_dcache_area(new_pgd, PTRS_PER_PGD * sizeof(pgd_t));
|
|
|
|
#ifdef CONFIG_ARM_LPAE
|
|
/*
|
|
* Allocate PMD table for modules and pkmap mappings.
|
|
*/
|
|
new_pud = pud_alloc(mm, new_pgd + pgd_index(MODULES_VADDR),
|
|
MODULES_VADDR);
|
|
if (!new_pud)
|
|
goto no_pud;
|
|
|
|
new_pmd = pmd_alloc(mm, new_pud, 0);
|
|
if (!new_pmd)
|
|
goto no_pmd;
|
|
#endif
|
|
|
|
if (!vectors_high()) {
|
|
/*
|
|
* On ARM, first page must always be allocated since it
|
|
* contains the machine vectors. The vectors are always high
|
|
* with LPAE.
|
|
*/
|
|
new_pud = pud_alloc(mm, new_pgd, 0);
|
|
if (!new_pud)
|
|
goto no_pud;
|
|
|
|
new_pmd = pmd_alloc(mm, new_pud, 0);
|
|
if (!new_pmd)
|
|
goto no_pmd;
|
|
|
|
new_pte = pte_alloc_map(mm, NULL, new_pmd, 0);
|
|
if (!new_pte)
|
|
goto no_pte;
|
|
|
|
init_pud = pud_offset(init_pgd, 0);
|
|
init_pmd = pmd_offset(init_pud, 0);
|
|
init_pte = pte_offset_map(init_pmd, 0);
|
|
set_pte_ext(new_pte + 0, init_pte[0], 0);
|
|
set_pte_ext(new_pte + 1, init_pte[1], 0);
|
|
pte_unmap(init_pte);
|
|
pte_unmap(new_pte);
|
|
}
|
|
|
|
return new_pgd;
|
|
|
|
no_pte:
|
|
pmd_free(mm, new_pmd);
|
|
no_pmd:
|
|
pud_free(mm, new_pud);
|
|
no_pud:
|
|
__pgd_free(new_pgd);
|
|
no_pgd:
|
|
return NULL;
|
|
}
|
|
|
|
void pgd_free(struct mm_struct *mm, pgd_t *pgd_base)
|
|
{
|
|
pgd_t *pgd;
|
|
pud_t *pud;
|
|
pmd_t *pmd;
|
|
pgtable_t pte;
|
|
|
|
if (!pgd_base)
|
|
return;
|
|
|
|
pgd = pgd_base + pgd_index(0);
|
|
if (pgd_none_or_clear_bad(pgd))
|
|
goto no_pgd;
|
|
|
|
pud = pud_offset(pgd, 0);
|
|
if (pud_none_or_clear_bad(pud))
|
|
goto no_pud;
|
|
|
|
pmd = pmd_offset(pud, 0);
|
|
if (pmd_none_or_clear_bad(pmd))
|
|
goto no_pmd;
|
|
|
|
pte = pmd_pgtable(*pmd);
|
|
pmd_clear(pmd);
|
|
pte_free(mm, pte);
|
|
no_pmd:
|
|
pud_clear(pud);
|
|
pmd_free(mm, pmd);
|
|
no_pud:
|
|
pgd_clear(pgd);
|
|
pud_free(mm, pud);
|
|
no_pgd:
|
|
#ifdef CONFIG_ARM_LPAE
|
|
/*
|
|
* Free modules/pkmap or identity pmd tables.
|
|
*/
|
|
for (pgd = pgd_base; pgd < pgd_base + PTRS_PER_PGD; pgd++) {
|
|
if (pgd_none_or_clear_bad(pgd))
|
|
continue;
|
|
if (pgd_val(*pgd) & L_PGD_SWAPPER)
|
|
continue;
|
|
pud = pud_offset(pgd, 0);
|
|
if (pud_none_or_clear_bad(pud))
|
|
continue;
|
|
pmd = pmd_offset(pud, 0);
|
|
pud_clear(pud);
|
|
pmd_free(mm, pmd);
|
|
pgd_clear(pgd);
|
|
pud_free(mm, pud);
|
|
}
|
|
#endif
|
|
__pgd_free(pgd_base);
|
|
}
|