linux/arch/sparc/kernel/urtt_fill.S
Khalid Aziz 74a0496748 sparc64: Add support for ADI (Application Data Integrity)
ADI is a new feature supported on SPARC M7 and newer processors to allow
hardware to catch rogue accesses to memory. ADI is supported for data
fetches only and not instruction fetches. An app can enable ADI on its
data pages, set version tags on them and use versioned addresses to
access the data pages. Upper bits of the address contain the version
tag. On M7 processors, upper four bits (bits 63-60) contain the version
tag. If a rogue app attempts to access ADI enabled data pages, its
access is blocked and processor generates an exception. Please see
Documentation/sparc/adi.txt for further details.

This patch extends mprotect to enable ADI (TSTATE.mcde), enable/disable
MCD (Memory Corruption Detection) on selected memory ranges, enable
TTE.mcd in PTEs, return ADI parameters to userspace and save/restore ADI
version tags on page swap out/in or migration. ADI is not enabled by
default for any task. A task must explicitly enable ADI on a memory
range and set version tag for ADI to be effective for the task.

Signed-off-by: Khalid Aziz <khalid.aziz@oracle.com>
Cc: Khalid Aziz <khalid@gonehiking.org>
Reviewed-by: Anthony Yznaga <anthony.yznaga@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-03-18 07:38:48 -07:00

106 lines
2.0 KiB
ArmAsm

/* SPDX-License-Identifier: GPL-2.0 */
#include <asm/thread_info.h>
#include <asm/trap_block.h>
#include <asm/spitfire.h>
#include <asm/ptrace.h>
#include <asm/head.h>
.text
.align 8
.globl user_rtt_fill_fixup_common
user_rtt_fill_fixup_common:
rdpr %cwp, %g1
add %g1, 1, %g1
wrpr %g1, 0x0, %cwp
rdpr %wstate, %g2
sll %g2, 3, %g2
wrpr %g2, 0x0, %wstate
/* We know %canrestore and %otherwin are both zero. */
sethi %hi(sparc64_kern_pri_context), %g2
ldx [%g2 + %lo(sparc64_kern_pri_context)], %g2
mov PRIMARY_CONTEXT, %g1
661: stxa %g2, [%g1] ASI_DMMU
.section .sun4v_1insn_patch, "ax"
.word 661b
stxa %g2, [%g1] ASI_MMU
.previous
sethi %hi(KERNBASE), %g1
flush %g1
mov %g4, %l4
mov %g5, %l5
brnz,pn %g3, 1f
mov %g3, %l3
or %g4, FAULT_CODE_WINFIXUP, %g4
stb %g4, [%g6 + TI_FAULT_CODE]
stx %g5, [%g6 + TI_FAULT_ADDR]
1:
mov %g6, %l1
wrpr %g0, 0x0, %tl
661: nop
.section .sun4v_1insn_patch, "ax"
.word 661b
SET_GL(0)
.previous
661: wrpr %g0, RTRAP_PSTATE, %pstate
.section .sun_m7_1insn_patch, "ax"
.word 661b
/* Re-enable PSTATE.mcde to maintain ADI security */
wrpr %g0, RTRAP_PSTATE|PSTATE_MCDE, %pstate
.previous
mov %l1, %g6
ldx [%g6 + TI_TASK], %g4
LOAD_PER_CPU_BASE(%g5, %g6, %g1, %g2, %g3)
brnz,pn %l3, 1f
nop
call do_sparc64_fault
add %sp, PTREGS_OFF, %o0
ba,pt %xcc, rtrap
nop
1: cmp %g3, 2
bne,pn %xcc, 2f
nop
sethi %hi(tlb_type), %g1
lduw [%g1 + %lo(tlb_type)], %g1
cmp %g1, 3
bne,pt %icc, 1f
add %sp, PTREGS_OFF, %o0
mov %l4, %o2
call sun4v_do_mna
mov %l5, %o1
ba,a,pt %xcc, rtrap
1: mov %l4, %o1
mov %l5, %o2
call mem_address_unaligned
nop
ba,a,pt %xcc, rtrap
2: sethi %hi(tlb_type), %g1
mov %l4, %o1
lduw [%g1 + %lo(tlb_type)], %g1
mov %l5, %o2
cmp %g1, 3
bne,pt %icc, 1f
add %sp, PTREGS_OFF, %o0
call sun4v_data_access_exception
nop
ba,a,pt %xcc, rtrap
nop
1: call spitfire_data_access_exception
nop
ba,a,pt %xcc, rtrap