kernel_optimize_test/arch/arm/mm/proc-v7-3level.S
Will Deacon 26ffd0d43b ARM: mm: introduce present, faulting entries for PAGE_NONE
PROT_NONE mappings apply the page protection attributes defined by _P000
which translate to PAGE_NONE for ARM. These attributes specify an XN,
RDONLY pte that is inaccessible to userspace. However, on kernels
configured without support for domains, such a pte *is* accessible to
the kernel and can be read via get_user, allowing tasks to read
PROT_NONE pages via syscalls such as read/write over a pipe.

This patch introduces a new software pte flag, L_PTE_NONE, that is set
to identify faulting, present entries.

Signed-off-by: Will Deacon <will.deacon@arm.com>
2012-11-09 14:13:20 +00:00

154 lines
4.5 KiB
ArmAsm

/*
* arch/arm/mm/proc-v7-3level.S
*
* Copyright (C) 2001 Deep Blue Solutions Ltd.
* Copyright (C) 2011 ARM Ltd.
* Author: Catalin Marinas <catalin.marinas@arm.com>
* based on arch/arm/mm/proc-v7-2level.S
*
* 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.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#define TTB_IRGN_NC (0 << 8)
#define TTB_IRGN_WBWA (1 << 8)
#define TTB_IRGN_WT (2 << 8)
#define TTB_IRGN_WB (3 << 8)
#define TTB_RGN_NC (0 << 10)
#define TTB_RGN_OC_WBWA (1 << 10)
#define TTB_RGN_OC_WT (2 << 10)
#define TTB_RGN_OC_WB (3 << 10)
#define TTB_S (3 << 12)
#define TTB_EAE (1 << 31)
/* PTWs cacheable, inner WB not shareable, outer WB not shareable */
#define TTB_FLAGS_UP (TTB_IRGN_WB|TTB_RGN_OC_WB)
#define PMD_FLAGS_UP (PMD_SECT_WB)
/* PTWs cacheable, inner WBWA shareable, outer WBWA not shareable */
#define TTB_FLAGS_SMP (TTB_IRGN_WBWA|TTB_S|TTB_RGN_OC_WBWA)
#define PMD_FLAGS_SMP (PMD_SECT_WBWA|PMD_SECT_S)
/*
* cpu_v7_switch_mm(pgd_phys, tsk)
*
* Set the translation table base pointer to be pgd_phys (physical address of
* the new TTB).
*/
ENTRY(cpu_v7_switch_mm)
#ifdef CONFIG_MMU
ldr r1, [r1, #MM_CONTEXT_ID] @ get mm->context.id
and r3, r1, #0xff
mov r3, r3, lsl #(48 - 32) @ ASID
mcrr p15, 0, r0, r3, c2 @ set TTB 0
isb
#endif
mov pc, lr
ENDPROC(cpu_v7_switch_mm)
/*
* cpu_v7_set_pte_ext(ptep, pte)
*
* Set a level 2 translation table entry.
* - ptep - pointer to level 3 translation table entry
* - pte - PTE value to store (64-bit in r2 and r3)
*/
ENTRY(cpu_v7_set_pte_ext)
#ifdef CONFIG_MMU
tst r2, #L_PTE_VALID
beq 1f
tst r3, #1 << (57 - 32) @ L_PTE_NONE
bicne r2, #L_PTE_VALID
bne 1f
tst r3, #1 << (55 - 32) @ L_PTE_DIRTY
orreq r2, #L_PTE_RDONLY
1: strd r2, r3, [r0]
mcr p15, 0, r0, c7, c10, 1 @ flush_pte
#endif
mov pc, lr
ENDPROC(cpu_v7_set_pte_ext)
/*
* Memory region attributes for LPAE (defined in pgtable-3level.h):
*
* n = AttrIndx[2:0]
*
* n MAIR
* UNCACHED 000 00000000
* BUFFERABLE 001 01000100
* DEV_WC 001 01000100
* WRITETHROUGH 010 10101010
* WRITEBACK 011 11101110
* DEV_CACHED 011 11101110
* DEV_SHARED 100 00000100
* DEV_NONSHARED 100 00000100
* unused 101
* unused 110
* WRITEALLOC 111 11111111
*/
.equ PRRR, 0xeeaa4400 @ MAIR0
.equ NMRR, 0xff000004 @ MAIR1
/*
* Macro for setting up the TTBRx and TTBCR registers.
* - \ttbr1 updated.
*/
.macro v7_ttb_setup, zero, ttbr0, ttbr1, tmp
ldr \tmp, =swapper_pg_dir @ swapper_pg_dir virtual address
cmp \ttbr1, \tmp @ PHYS_OFFSET > PAGE_OFFSET? (branch below)
mrc p15, 0, \tmp, c2, c0, 2 @ TTB control register
orr \tmp, \tmp, #TTB_EAE
ALT_SMP(orr \tmp, \tmp, #TTB_FLAGS_SMP)
ALT_UP(orr \tmp, \tmp, #TTB_FLAGS_UP)
ALT_SMP(orr \tmp, \tmp, #TTB_FLAGS_SMP << 16)
ALT_UP(orr \tmp, \tmp, #TTB_FLAGS_UP << 16)
/*
* TTBR0/TTBR1 split (PAGE_OFFSET):
* 0x40000000: T0SZ = 2, T1SZ = 0 (not used)
* 0x80000000: T0SZ = 0, T1SZ = 1
* 0xc0000000: T0SZ = 0, T1SZ = 2
*
* Only use this feature if PHYS_OFFSET <= PAGE_OFFSET, otherwise
* booting secondary CPUs would end up using TTBR1 for the identity
* mapping set up in TTBR0.
*/
bhi 9001f @ PHYS_OFFSET > PAGE_OFFSET?
orr \tmp, \tmp, #(((PAGE_OFFSET >> 30) - 1) << 16) @ TTBCR.T1SZ
#if defined CONFIG_VMSPLIT_2G
/* PAGE_OFFSET == 0x80000000, T1SZ == 1 */
add \ttbr1, \ttbr1, #1 << 4 @ skip two L1 entries
#elif defined CONFIG_VMSPLIT_3G
/* PAGE_OFFSET == 0xc0000000, T1SZ == 2 */
add \ttbr1, \ttbr1, #4096 * (1 + 3) @ only L2 used, skip pgd+3*pmd
#endif
/* CONFIG_VMSPLIT_1G does not need TTBR1 adjustment */
9001: mcr p15, 0, \tmp, c2, c0, 2 @ TTB control register
mcrr p15, 1, \ttbr1, \zero, c2 @ load TTBR1
.endm
__CPUINIT
/*
* AT
* TFR EV X F IHD LR S
* .EEE ..EE PUI. .TAT 4RVI ZWRS BLDP WCAM
* rxxx rrxx xxx0 0101 xxxx xxxx x111 xxxx < forced
* 11 0 110 1 0011 1100 .111 1101 < we want
*/
.align 2
.type v7_crval, #object
v7_crval:
crval clear=0x0120c302, mmuset=0x30c23c7d, ucset=0x00c01c7c
.previous