178 lines
3.6 KiB
ArmAsm
178 lines
3.6 KiB
ArmAsm
/* SPDX-License-Identifier: GPL-2.0-only */
|
|
/*
|
|
* Copyright (C) 2020 ARM Ltd.
|
|
*/
|
|
#include <linux/linkage.h>
|
|
|
|
#include <asm/asm-uaccess.h>
|
|
#include <asm/assembler.h>
|
|
#include <asm/mte.h>
|
|
#include <asm/page.h>
|
|
#include <asm/sysreg.h>
|
|
|
|
.arch armv8.5-a+memtag
|
|
|
|
/*
|
|
* multitag_transfer_size - set \reg to the block size that is accessed by the
|
|
* LDGM/STGM instructions.
|
|
*/
|
|
.macro multitag_transfer_size, reg, tmp
|
|
mrs_s \reg, SYS_GMID_EL1
|
|
ubfx \reg, \reg, #SYS_GMID_EL1_BS_SHIFT, #SYS_GMID_EL1_BS_SIZE
|
|
mov \tmp, #4
|
|
lsl \reg, \tmp, \reg
|
|
.endm
|
|
|
|
/*
|
|
* Clear the tags in a page
|
|
* x0 - address of the page to be cleared
|
|
*/
|
|
SYM_FUNC_START(mte_clear_page_tags)
|
|
multitag_transfer_size x1, x2
|
|
1: stgm xzr, [x0]
|
|
add x0, x0, x1
|
|
tst x0, #(PAGE_SIZE - 1)
|
|
b.ne 1b
|
|
ret
|
|
SYM_FUNC_END(mte_clear_page_tags)
|
|
|
|
/*
|
|
* Zero the page and tags at the same time
|
|
*
|
|
* Parameters:
|
|
* x0 - address to the beginning of the page
|
|
*/
|
|
SYM_FUNC_START(mte_zero_clear_page_tags)
|
|
and x0, x0, #(1 << MTE_TAG_SHIFT) - 1 // clear the tag
|
|
mrs x1, dczid_el0
|
|
tbnz x1, #4, 2f // Branch if DC GZVA is prohibited
|
|
and w1, w1, #0xf
|
|
mov x2, #4
|
|
lsl x1, x2, x1
|
|
|
|
1: dc gzva, x0
|
|
add x0, x0, x1
|
|
tst x0, #(PAGE_SIZE - 1)
|
|
b.ne 1b
|
|
ret
|
|
|
|
2: stz2g x0, [x0], #(MTE_GRANULE_SIZE * 2)
|
|
tst x0, #(PAGE_SIZE - 1)
|
|
b.ne 2b
|
|
ret
|
|
SYM_FUNC_END(mte_zero_clear_page_tags)
|
|
|
|
/*
|
|
* Copy the tags from the source page to the destination one
|
|
* x0 - address of the destination page
|
|
* x1 - address of the source page
|
|
*/
|
|
SYM_FUNC_START(mte_copy_page_tags)
|
|
mov x2, x0
|
|
mov x3, x1
|
|
multitag_transfer_size x5, x6
|
|
1: ldgm x4, [x3]
|
|
stgm x4, [x2]
|
|
add x2, x2, x5
|
|
add x3, x3, x5
|
|
tst x2, #(PAGE_SIZE - 1)
|
|
b.ne 1b
|
|
ret
|
|
SYM_FUNC_END(mte_copy_page_tags)
|
|
|
|
/*
|
|
* Read tags from a user buffer (one tag per byte) and set the corresponding
|
|
* tags at the given kernel address. Used by PTRACE_POKEMTETAGS.
|
|
* x0 - kernel address (to)
|
|
* x1 - user buffer (from)
|
|
* x2 - number of tags/bytes (n)
|
|
* Returns:
|
|
* x0 - number of tags read/set
|
|
*/
|
|
SYM_FUNC_START(mte_copy_tags_from_user)
|
|
mov x3, x1
|
|
cbz x2, 2f
|
|
1:
|
|
user_ldst 2f, ldtrb, w4, x1, 0
|
|
lsl x4, x4, #MTE_TAG_SHIFT
|
|
stg x4, [x0], #MTE_GRANULE_SIZE
|
|
add x1, x1, #1
|
|
subs x2, x2, #1
|
|
b.ne 1b
|
|
|
|
// exception handling and function return
|
|
2: sub x0, x1, x3 // update the number of tags set
|
|
ret
|
|
SYM_FUNC_END(mte_copy_tags_from_user)
|
|
|
|
/*
|
|
* Get the tags from a kernel address range and write the tag values to the
|
|
* given user buffer (one tag per byte). Used by PTRACE_PEEKMTETAGS.
|
|
* x0 - user buffer (to)
|
|
* x1 - kernel address (from)
|
|
* x2 - number of tags/bytes (n)
|
|
* Returns:
|
|
* x0 - number of tags read/set
|
|
*/
|
|
SYM_FUNC_START(mte_copy_tags_to_user)
|
|
mov x3, x0
|
|
cbz x2, 2f
|
|
1:
|
|
ldg x4, [x1]
|
|
ubfx x4, x4, #MTE_TAG_SHIFT, #MTE_TAG_SIZE
|
|
user_ldst 2f, sttrb, w4, x0, 0
|
|
add x0, x0, #1
|
|
add x1, x1, #MTE_GRANULE_SIZE
|
|
subs x2, x2, #1
|
|
b.ne 1b
|
|
|
|
// exception handling and function return
|
|
2: sub x0, x0, x3 // update the number of tags copied
|
|
ret
|
|
SYM_FUNC_END(mte_copy_tags_to_user)
|
|
|
|
/*
|
|
* Save the tags in a page
|
|
* x0 - page address
|
|
* x1 - tag storage
|
|
*/
|
|
SYM_FUNC_START(mte_save_page_tags)
|
|
multitag_transfer_size x7, x5
|
|
1:
|
|
mov x2, #0
|
|
2:
|
|
ldgm x5, [x0]
|
|
orr x2, x2, x5
|
|
add x0, x0, x7
|
|
tst x0, #0xFF // 16 tag values fit in a register,
|
|
b.ne 2b // which is 16*16=256 bytes
|
|
|
|
str x2, [x1], #8
|
|
|
|
tst x0, #(PAGE_SIZE - 1)
|
|
b.ne 1b
|
|
|
|
ret
|
|
SYM_FUNC_END(mte_save_page_tags)
|
|
|
|
/*
|
|
* Restore the tags in a page
|
|
* x0 - page address
|
|
* x1 - tag storage
|
|
*/
|
|
SYM_FUNC_START(mte_restore_page_tags)
|
|
multitag_transfer_size x7, x5
|
|
1:
|
|
ldr x2, [x1], #8
|
|
2:
|
|
stgm x2, [x0]
|
|
add x0, x0, x7
|
|
tst x0, #0xFF
|
|
b.ne 2b
|
|
|
|
tst x0, #(PAGE_SIZE - 1)
|
|
b.ne 1b
|
|
|
|
ret
|
|
SYM_FUNC_END(mte_restore_page_tags)
|