linux-brain/arch/arm64/kernel/insn.c
Mark Rutland 3283bd6d19 arm64: insn: consistently handle exit text
[ Upstream commit ca2ef4ffabbef25644e02a98b0f48869f8be0375 ]

A kernel built with KASAN && FTRACE_WITH_REGS && !MODULES, produces a
boot-time splat in the bowels of ftrace:

| [    0.000000] ftrace: allocating 32281 entries in 127 pages
| [    0.000000] ------------[ cut here ]------------
| [    0.000000] WARNING: CPU: 0 PID: 0 at kernel/trace/ftrace.c:2019 ftrace_bug+0x27c/0x328
| [    0.000000] CPU: 0 PID: 0 Comm: swapper Not tainted 5.4.0-rc3-00008-g7f08ae53a7e3 #13
| [    0.000000] Hardware name: linux,dummy-virt (DT)
| [    0.000000] pstate: 60000085 (nZCv daIf -PAN -UAO)
| [    0.000000] pc : ftrace_bug+0x27c/0x328
| [    0.000000] lr : ftrace_init+0x640/0x6cc
| [    0.000000] sp : ffffa000120e7e00
| [    0.000000] x29: ffffa000120e7e00 x28: ffff00006ac01b10
| [    0.000000] x27: ffff00006ac898c0 x26: dfffa00000000000
| [    0.000000] x25: ffffa000120ef290 x24: ffffa0001216df40
| [    0.000000] x23: 000000000000018d x22: ffffa0001244c700
| [    0.000000] x21: ffffa00011bf393c x20: ffff00006ac898c0
| [    0.000000] x19: 00000000ffffffff x18: 0000000000001584
| [    0.000000] x17: 0000000000001540 x16: 0000000000000007
| [    0.000000] x15: 0000000000000000 x14: ffffa00010432770
| [    0.000000] x13: ffff940002483519 x12: 1ffff40002483518
| [    0.000000] x11: 1ffff40002483518 x10: ffff940002483518
| [    0.000000] x9 : dfffa00000000000 x8 : 0000000000000001
| [    0.000000] x7 : ffff940002483519 x6 : ffffa0001241a8c0
| [    0.000000] x5 : ffff940002483519 x4 : ffff940002483519
| [    0.000000] x3 : ffffa00011780870 x2 : 0000000000000001
| [    0.000000] x1 : 1fffe0000d591318 x0 : 0000000000000000
| [    0.000000] Call trace:
| [    0.000000]  ftrace_bug+0x27c/0x328
| [    0.000000]  ftrace_init+0x640/0x6cc
| [    0.000000]  start_kernel+0x27c/0x654
| [    0.000000] random: get_random_bytes called from print_oops_end_marker+0x30/0x60 with crng_init=0
| [    0.000000] ---[ end trace 0000000000000000 ]---
| [    0.000000] ftrace faulted on writing
| [    0.000000] [<ffffa00011bf393c>] _GLOBAL__sub_D_65535_0___tracepoint_initcall_level+0x4/0x28
| [    0.000000] Initializing ftrace call sites
| [    0.000000] ftrace record flags: 0
| [    0.000000]  (0)
| [    0.000000]  expected tramp: ffffa000100b3344

This is due to an unfortunate combination of several factors.

Building with KASAN results in the compiler generating anonymous
functions to register/unregister global variables against the shadow
memory. These functions are placed in .text.startup/.text.exit, and
given mangled names like _GLOBAL__sub_{I,D}_65535_0_$OTHER_SYMBOL. The
kernel linker script places these in .init.text and .exit.text
respectively, which are both discarded at runtime as part of initmem.

Building with FTRACE_WITH_REGS uses -fpatchable-function-entry=2, which
also instruments KASAN's anonymous functions. When these are discarded
with the rest of initmem, ftrace removes dangling references to these
call sites.

Building without MODULES implicitly disables STRICT_MODULE_RWX, and
causes arm64's patch_map() function to treat any !core_kernel_text()
symbol as something that can be modified in-place. As core_kernel_text()
is only true for .text and .init.text, with the latter depending on
system_state < SYSTEM_RUNNING, we'll treat .exit.text as something that
can be patched in-place. However, .exit.text is mapped read-only.

Hence in this configuration the ftrace init code blows up while trying
to patch one of the functions generated by KASAN.

We could try to filter out the call sites in .exit.text rather than
initializing them, but this would be inconsistent with how we handle
.init.text, and requires hooking into core bits of ftrace. The behaviour
of patch_map() is also inconsistent today, so instead let's clean that
up and have it consistently handle .exit.text.

This patch teaches patch_map() to handle .exit.text at init time,
preventing the boot-time splat above. The flow of patch_map() is
reworked to make the logic clearer and minimize redundant
conditionality.

Fixes: 3b23e4991fb66f6d ("arm64: implement ftrace with regs")
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Amit Daniel Kachhap <amit.kachhap@arm.com>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Torsten Duwe <duwe@suse.de>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-10-01 13:17:23 +02:00

1678 lines
40 KiB
C

// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (C) 2013 Huawei Ltd.
* Author: Jiang Liu <liuj97@gmail.com>
*
* Copyright (C) 2014-2016 Zi Shen Lim <zlim.lnx@gmail.com>
*/
#include <linux/bitops.h>
#include <linux/bug.h>
#include <linux/compiler.h>
#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/smp.h>
#include <linux/spinlock.h>
#include <linux/stop_machine.h>
#include <linux/types.h>
#include <linux/uaccess.h>
#include <asm/cacheflush.h>
#include <asm/debug-monitors.h>
#include <asm/fixmap.h>
#include <asm/insn.h>
#include <asm/kprobes.h>
#include <asm/sections.h>
#define AARCH64_INSN_SF_BIT BIT(31)
#define AARCH64_INSN_N_BIT BIT(22)
#define AARCH64_INSN_LSL_12 BIT(22)
static const int aarch64_insn_encoding_class[] = {
AARCH64_INSN_CLS_UNKNOWN,
AARCH64_INSN_CLS_UNKNOWN,
AARCH64_INSN_CLS_UNKNOWN,
AARCH64_INSN_CLS_UNKNOWN,
AARCH64_INSN_CLS_LDST,
AARCH64_INSN_CLS_DP_REG,
AARCH64_INSN_CLS_LDST,
AARCH64_INSN_CLS_DP_FPSIMD,
AARCH64_INSN_CLS_DP_IMM,
AARCH64_INSN_CLS_DP_IMM,
AARCH64_INSN_CLS_BR_SYS,
AARCH64_INSN_CLS_BR_SYS,
AARCH64_INSN_CLS_LDST,
AARCH64_INSN_CLS_DP_REG,
AARCH64_INSN_CLS_LDST,
AARCH64_INSN_CLS_DP_FPSIMD,
};
enum aarch64_insn_encoding_class __kprobes aarch64_get_insn_class(u32 insn)
{
return aarch64_insn_encoding_class[(insn >> 25) & 0xf];
}
/* NOP is an alias of HINT */
bool __kprobes aarch64_insn_is_nop(u32 insn)
{
if (!aarch64_insn_is_hint(insn))
return false;
switch (insn & 0xFE0) {
case AARCH64_INSN_HINT_YIELD:
case AARCH64_INSN_HINT_WFE:
case AARCH64_INSN_HINT_WFI:
case AARCH64_INSN_HINT_SEV:
case AARCH64_INSN_HINT_SEVL:
return false;
default:
return true;
}
}
bool aarch64_insn_is_branch_imm(u32 insn)
{
return (aarch64_insn_is_b(insn) || aarch64_insn_is_bl(insn) ||
aarch64_insn_is_tbz(insn) || aarch64_insn_is_tbnz(insn) ||
aarch64_insn_is_cbz(insn) || aarch64_insn_is_cbnz(insn) ||
aarch64_insn_is_bcond(insn));
}
static DEFINE_RAW_SPINLOCK(patch_lock);
static bool is_exit_text(unsigned long addr)
{
/* discarded with init text/data */
return system_state < SYSTEM_RUNNING &&
addr >= (unsigned long)__exittext_begin &&
addr < (unsigned long)__exittext_end;
}
static bool is_image_text(unsigned long addr)
{
return core_kernel_text(addr) || is_exit_text(addr);
}
static void __kprobes *patch_map(void *addr, int fixmap)
{
unsigned long uintaddr = (uintptr_t) addr;
bool image = is_image_text(uintaddr);
struct page *page;
if (image)
page = phys_to_page(__pa_symbol(addr));
else if (IS_ENABLED(CONFIG_STRICT_MODULE_RWX))
page = vmalloc_to_page(addr);
else
return addr;
BUG_ON(!page);
return (void *)set_fixmap_offset(fixmap, page_to_phys(page) +
(uintaddr & ~PAGE_MASK));
}
static void __kprobes patch_unmap(int fixmap)
{
clear_fixmap(fixmap);
}
/*
* In ARMv8-A, A64 instructions have a fixed length of 32 bits and are always
* little-endian.
*/
int __kprobes aarch64_insn_read(void *addr, u32 *insnp)
{
int ret;
__le32 val;
ret = probe_kernel_read(&val, addr, AARCH64_INSN_SIZE);
if (!ret)
*insnp = le32_to_cpu(val);
return ret;
}
static int __kprobes __aarch64_insn_write(void *addr, __le32 insn)
{
void *waddr = addr;
unsigned long flags = 0;
int ret;
raw_spin_lock_irqsave(&patch_lock, flags);
waddr = patch_map(addr, FIX_TEXT_POKE0);
ret = probe_kernel_write(waddr, &insn, AARCH64_INSN_SIZE);
patch_unmap(FIX_TEXT_POKE0);
raw_spin_unlock_irqrestore(&patch_lock, flags);
return ret;
}
int __kprobes aarch64_insn_write(void *addr, u32 insn)
{
return __aarch64_insn_write(addr, cpu_to_le32(insn));
}
bool __kprobes aarch64_insn_uses_literal(u32 insn)
{
/* ldr/ldrsw (literal), prfm */
return aarch64_insn_is_ldr_lit(insn) ||
aarch64_insn_is_ldrsw_lit(insn) ||
aarch64_insn_is_adr_adrp(insn) ||
aarch64_insn_is_prfm_lit(insn);
}
bool __kprobes aarch64_insn_is_branch(u32 insn)
{
/* b, bl, cb*, tb*, b.cond, br, blr */
return aarch64_insn_is_b(insn) ||
aarch64_insn_is_bl(insn) ||
aarch64_insn_is_cbz(insn) ||
aarch64_insn_is_cbnz(insn) ||
aarch64_insn_is_tbz(insn) ||
aarch64_insn_is_tbnz(insn) ||
aarch64_insn_is_ret(insn) ||
aarch64_insn_is_br(insn) ||
aarch64_insn_is_blr(insn) ||
aarch64_insn_is_bcond(insn);
}
int __kprobes aarch64_insn_patch_text_nosync(void *addr, u32 insn)
{
u32 *tp = addr;
int ret;
/* A64 instructions must be word aligned */
if ((uintptr_t)tp & 0x3)
return -EINVAL;
ret = aarch64_insn_write(tp, insn);
if (ret == 0)
__flush_icache_range((uintptr_t)tp,
(uintptr_t)tp + AARCH64_INSN_SIZE);
return ret;
}
struct aarch64_insn_patch {
void **text_addrs;
u32 *new_insns;
int insn_cnt;
atomic_t cpu_count;
};
static int __kprobes aarch64_insn_patch_text_cb(void *arg)
{
int i, ret = 0;
struct aarch64_insn_patch *pp = arg;
/* The first CPU becomes master */
if (atomic_inc_return(&pp->cpu_count) == 1) {
for (i = 0; ret == 0 && i < pp->insn_cnt; i++)
ret = aarch64_insn_patch_text_nosync(pp->text_addrs[i],
pp->new_insns[i]);
/* Notify other processors with an additional increment. */
atomic_inc(&pp->cpu_count);
} else {
while (atomic_read(&pp->cpu_count) <= num_online_cpus())
cpu_relax();
isb();
}
return ret;
}
int __kprobes aarch64_insn_patch_text(void *addrs[], u32 insns[], int cnt)
{
struct aarch64_insn_patch patch = {
.text_addrs = addrs,
.new_insns = insns,
.insn_cnt = cnt,
.cpu_count = ATOMIC_INIT(0),
};
if (cnt <= 0)
return -EINVAL;
return stop_machine_cpuslocked(aarch64_insn_patch_text_cb, &patch,
cpu_online_mask);
}
static int __kprobes aarch64_get_imm_shift_mask(enum aarch64_insn_imm_type type,
u32 *maskp, int *shiftp)
{
u32 mask;
int shift;
switch (type) {
case AARCH64_INSN_IMM_26:
mask = BIT(26) - 1;
shift = 0;
break;
case AARCH64_INSN_IMM_19:
mask = BIT(19) - 1;
shift = 5;
break;
case AARCH64_INSN_IMM_16:
mask = BIT(16) - 1;
shift = 5;
break;
case AARCH64_INSN_IMM_14:
mask = BIT(14) - 1;
shift = 5;
break;
case AARCH64_INSN_IMM_12:
mask = BIT(12) - 1;
shift = 10;
break;
case AARCH64_INSN_IMM_9:
mask = BIT(9) - 1;
shift = 12;
break;
case AARCH64_INSN_IMM_7:
mask = BIT(7) - 1;
shift = 15;
break;
case AARCH64_INSN_IMM_6:
case AARCH64_INSN_IMM_S:
mask = BIT(6) - 1;
shift = 10;
break;
case AARCH64_INSN_IMM_R:
mask = BIT(6) - 1;
shift = 16;
break;
case AARCH64_INSN_IMM_N:
mask = 1;
shift = 22;
break;
default:
return -EINVAL;
}
*maskp = mask;
*shiftp = shift;
return 0;
}
#define ADR_IMM_HILOSPLIT 2
#define ADR_IMM_SIZE SZ_2M
#define ADR_IMM_LOMASK ((1 << ADR_IMM_HILOSPLIT) - 1)
#define ADR_IMM_HIMASK ((ADR_IMM_SIZE >> ADR_IMM_HILOSPLIT) - 1)
#define ADR_IMM_LOSHIFT 29
#define ADR_IMM_HISHIFT 5
u64 aarch64_insn_decode_immediate(enum aarch64_insn_imm_type type, u32 insn)
{
u32 immlo, immhi, mask;
int shift;
switch (type) {
case AARCH64_INSN_IMM_ADR:
shift = 0;
immlo = (insn >> ADR_IMM_LOSHIFT) & ADR_IMM_LOMASK;
immhi = (insn >> ADR_IMM_HISHIFT) & ADR_IMM_HIMASK;
insn = (immhi << ADR_IMM_HILOSPLIT) | immlo;
mask = ADR_IMM_SIZE - 1;
break;
default:
if (aarch64_get_imm_shift_mask(type, &mask, &shift) < 0) {
pr_err("aarch64_insn_decode_immediate: unknown immediate encoding %d\n",
type);
return 0;
}
}
return (insn >> shift) & mask;
}
u32 __kprobes aarch64_insn_encode_immediate(enum aarch64_insn_imm_type type,
u32 insn, u64 imm)
{
u32 immlo, immhi, mask;
int shift;
if (insn == AARCH64_BREAK_FAULT)
return AARCH64_BREAK_FAULT;
switch (type) {
case AARCH64_INSN_IMM_ADR:
shift = 0;
immlo = (imm & ADR_IMM_LOMASK) << ADR_IMM_LOSHIFT;
imm >>= ADR_IMM_HILOSPLIT;
immhi = (imm & ADR_IMM_HIMASK) << ADR_IMM_HISHIFT;
imm = immlo | immhi;
mask = ((ADR_IMM_LOMASK << ADR_IMM_LOSHIFT) |
(ADR_IMM_HIMASK << ADR_IMM_HISHIFT));
break;
default:
if (aarch64_get_imm_shift_mask(type, &mask, &shift) < 0) {
pr_err("aarch64_insn_encode_immediate: unknown immediate encoding %d\n",
type);
return AARCH64_BREAK_FAULT;
}
}
/* Update the immediate field. */
insn &= ~(mask << shift);
insn |= (imm & mask) << shift;
return insn;
}
u32 aarch64_insn_decode_register(enum aarch64_insn_register_type type,
u32 insn)
{
int shift;
switch (type) {
case AARCH64_INSN_REGTYPE_RT:
case AARCH64_INSN_REGTYPE_RD:
shift = 0;
break;
case AARCH64_INSN_REGTYPE_RN:
shift = 5;
break;
case AARCH64_INSN_REGTYPE_RT2:
case AARCH64_INSN_REGTYPE_RA:
shift = 10;
break;
case AARCH64_INSN_REGTYPE_RM:
shift = 16;
break;
default:
pr_err("%s: unknown register type encoding %d\n", __func__,
type);
return 0;
}
return (insn >> shift) & GENMASK(4, 0);
}
static u32 aarch64_insn_encode_register(enum aarch64_insn_register_type type,
u32 insn,
enum aarch64_insn_register reg)
{
int shift;
if (insn == AARCH64_BREAK_FAULT)
return AARCH64_BREAK_FAULT;
if (reg < AARCH64_INSN_REG_0 || reg > AARCH64_INSN_REG_SP) {
pr_err("%s: unknown register encoding %d\n", __func__, reg);
return AARCH64_BREAK_FAULT;
}
switch (type) {
case AARCH64_INSN_REGTYPE_RT:
case AARCH64_INSN_REGTYPE_RD:
shift = 0;
break;
case AARCH64_INSN_REGTYPE_RN:
shift = 5;
break;
case AARCH64_INSN_REGTYPE_RT2:
case AARCH64_INSN_REGTYPE_RA:
shift = 10;
break;
case AARCH64_INSN_REGTYPE_RM:
case AARCH64_INSN_REGTYPE_RS:
shift = 16;
break;
default:
pr_err("%s: unknown register type encoding %d\n", __func__,
type);
return AARCH64_BREAK_FAULT;
}
insn &= ~(GENMASK(4, 0) << shift);
insn |= reg << shift;
return insn;
}
static u32 aarch64_insn_encode_ldst_size(enum aarch64_insn_size_type type,
u32 insn)
{
u32 size;
switch (type) {
case AARCH64_INSN_SIZE_8:
size = 0;
break;
case AARCH64_INSN_SIZE_16:
size = 1;
break;
case AARCH64_INSN_SIZE_32:
size = 2;
break;
case AARCH64_INSN_SIZE_64:
size = 3;
break;
default:
pr_err("%s: unknown size encoding %d\n", __func__, type);
return AARCH64_BREAK_FAULT;
}
insn &= ~GENMASK(31, 30);
insn |= size << 30;
return insn;
}
static inline long branch_imm_common(unsigned long pc, unsigned long addr,
long range)
{
long offset;
if ((pc & 0x3) || (addr & 0x3)) {
pr_err("%s: A64 instructions must be word aligned\n", __func__);
return range;
}
offset = ((long)addr - (long)pc);
if (offset < -range || offset >= range) {
pr_err("%s: offset out of range\n", __func__);
return range;
}
return offset;
}
u32 __kprobes aarch64_insn_gen_branch_imm(unsigned long pc, unsigned long addr,
enum aarch64_insn_branch_type type)
{
u32 insn;
long offset;
/*
* B/BL support [-128M, 128M) offset
* ARM64 virtual address arrangement guarantees all kernel and module
* texts are within +/-128M.
*/
offset = branch_imm_common(pc, addr, SZ_128M);
if (offset >= SZ_128M)
return AARCH64_BREAK_FAULT;
switch (type) {
case AARCH64_INSN_BRANCH_LINK:
insn = aarch64_insn_get_bl_value();
break;
case AARCH64_INSN_BRANCH_NOLINK:
insn = aarch64_insn_get_b_value();
break;
default:
pr_err("%s: unknown branch encoding %d\n", __func__, type);
return AARCH64_BREAK_FAULT;
}
return aarch64_insn_encode_immediate(AARCH64_INSN_IMM_26, insn,
offset >> 2);
}
u32 aarch64_insn_gen_comp_branch_imm(unsigned long pc, unsigned long addr,
enum aarch64_insn_register reg,
enum aarch64_insn_variant variant,
enum aarch64_insn_branch_type type)
{
u32 insn;
long offset;
offset = branch_imm_common(pc, addr, SZ_1M);
if (offset >= SZ_1M)
return AARCH64_BREAK_FAULT;
switch (type) {
case AARCH64_INSN_BRANCH_COMP_ZERO:
insn = aarch64_insn_get_cbz_value();
break;
case AARCH64_INSN_BRANCH_COMP_NONZERO:
insn = aarch64_insn_get_cbnz_value();
break;
default:
pr_err("%s: unknown branch encoding %d\n", __func__, type);
return AARCH64_BREAK_FAULT;
}
switch (variant) {
case AARCH64_INSN_VARIANT_32BIT:
break;
case AARCH64_INSN_VARIANT_64BIT:
insn |= AARCH64_INSN_SF_BIT;
break;
default:
pr_err("%s: unknown variant encoding %d\n", __func__, variant);
return AARCH64_BREAK_FAULT;
}
insn = aarch64_insn_encode_register(AARCH64_INSN_REGTYPE_RT, insn, reg);
return aarch64_insn_encode_immediate(AARCH64_INSN_IMM_19, insn,
offset >> 2);
}
u32 aarch64_insn_gen_cond_branch_imm(unsigned long pc, unsigned long addr,
enum aarch64_insn_condition cond)
{
u32 insn;
long offset;
offset = branch_imm_common(pc, addr, SZ_1M);
insn = aarch64_insn_get_bcond_value();
if (cond < AARCH64_INSN_COND_EQ || cond > AARCH64_INSN_COND_AL) {
pr_err("%s: unknown condition encoding %d\n", __func__, cond);
return AARCH64_BREAK_FAULT;
}
insn |= cond;
return aarch64_insn_encode_immediate(AARCH64_INSN_IMM_19, insn,
offset >> 2);
}
u32 __kprobes aarch64_insn_gen_hint(enum aarch64_insn_hint_op op)
{
return aarch64_insn_get_hint_value() | op;
}
u32 __kprobes aarch64_insn_gen_nop(void)
{
return aarch64_insn_gen_hint(AARCH64_INSN_HINT_NOP);
}
u32 aarch64_insn_gen_branch_reg(enum aarch64_insn_register reg,
enum aarch64_insn_branch_type type)
{
u32 insn;
switch (type) {
case AARCH64_INSN_BRANCH_NOLINK:
insn = aarch64_insn_get_br_value();
break;
case AARCH64_INSN_BRANCH_LINK:
insn = aarch64_insn_get_blr_value();
break;
case AARCH64_INSN_BRANCH_RETURN:
insn = aarch64_insn_get_ret_value();
break;
default:
pr_err("%s: unknown branch encoding %d\n", __func__, type);
return AARCH64_BREAK_FAULT;
}
return aarch64_insn_encode_register(AARCH64_INSN_REGTYPE_RN, insn, reg);
}
u32 aarch64_insn_gen_load_store_reg(enum aarch64_insn_register reg,
enum aarch64_insn_register base,
enum aarch64_insn_register offset,
enum aarch64_insn_size_type size,
enum aarch64_insn_ldst_type type)
{
u32 insn;
switch (type) {
case AARCH64_INSN_LDST_LOAD_REG_OFFSET:
insn = aarch64_insn_get_ldr_reg_value();
break;
case AARCH64_INSN_LDST_STORE_REG_OFFSET:
insn = aarch64_insn_get_str_reg_value();
break;
default:
pr_err("%s: unknown load/store encoding %d\n", __func__, type);
return AARCH64_BREAK_FAULT;
}
insn = aarch64_insn_encode_ldst_size(size, insn);
insn = aarch64_insn_encode_register(AARCH64_INSN_REGTYPE_RT, insn, reg);
insn = aarch64_insn_encode_register(AARCH64_INSN_REGTYPE_RN, insn,
base);
return aarch64_insn_encode_register(AARCH64_INSN_REGTYPE_RM, insn,
offset);
}
u32 aarch64_insn_gen_load_store_pair(enum aarch64_insn_register reg1,
enum aarch64_insn_register reg2,
enum aarch64_insn_register base,
int offset,
enum aarch64_insn_variant variant,
enum aarch64_insn_ldst_type type)
{
u32 insn;
int shift;
switch (type) {
case AARCH64_INSN_LDST_LOAD_PAIR_PRE_INDEX:
insn = aarch64_insn_get_ldp_pre_value();
break;
case AARCH64_INSN_LDST_STORE_PAIR_PRE_INDEX:
insn = aarch64_insn_get_stp_pre_value();
break;
case AARCH64_INSN_LDST_LOAD_PAIR_POST_INDEX:
insn = aarch64_insn_get_ldp_post_value();
break;
case AARCH64_INSN_LDST_STORE_PAIR_POST_INDEX:
insn = aarch64_insn_get_stp_post_value();
break;
default:
pr_err("%s: unknown load/store encoding %d\n", __func__, type);
return AARCH64_BREAK_FAULT;
}
switch (variant) {
case AARCH64_INSN_VARIANT_32BIT:
if ((offset & 0x3) || (offset < -256) || (offset > 252)) {
pr_err("%s: offset must be multiples of 4 in the range of [-256, 252] %d\n",
__func__, offset);
return AARCH64_BREAK_FAULT;
}
shift = 2;
break;
case AARCH64_INSN_VARIANT_64BIT:
if ((offset & 0x7) || (offset < -512) || (offset > 504)) {
pr_err("%s: offset must be multiples of 8 in the range of [-512, 504] %d\n",
__func__, offset);
return AARCH64_BREAK_FAULT;
}
shift = 3;
insn |= AARCH64_INSN_SF_BIT;
break;
default:
pr_err("%s: unknown variant encoding %d\n", __func__, variant);
return AARCH64_BREAK_FAULT;
}
insn = aarch64_insn_encode_register(AARCH64_INSN_REGTYPE_RT, insn,
reg1);
insn = aarch64_insn_encode_register(AARCH64_INSN_REGTYPE_RT2, insn,
reg2);
insn = aarch64_insn_encode_register(AARCH64_INSN_REGTYPE_RN, insn,
base);
return aarch64_insn_encode_immediate(AARCH64_INSN_IMM_7, insn,
offset >> shift);
}
u32 aarch64_insn_gen_load_store_ex(enum aarch64_insn_register reg,
enum aarch64_insn_register base,
enum aarch64_insn_register state,
enum aarch64_insn_size_type size,
enum aarch64_insn_ldst_type type)
{
u32 insn;
switch (type) {
case AARCH64_INSN_LDST_LOAD_EX:
insn = aarch64_insn_get_load_ex_value();
break;
case AARCH64_INSN_LDST_STORE_EX:
insn = aarch64_insn_get_store_ex_value();
break;
default:
pr_err("%s: unknown load/store exclusive encoding %d\n", __func__, type);
return AARCH64_BREAK_FAULT;
}
insn = aarch64_insn_encode_ldst_size(size, insn);
insn = aarch64_insn_encode_register(AARCH64_INSN_REGTYPE_RT, insn,
reg);
insn = aarch64_insn_encode_register(AARCH64_INSN_REGTYPE_RN, insn,
base);
insn = aarch64_insn_encode_register(AARCH64_INSN_REGTYPE_RT2, insn,
AARCH64_INSN_REG_ZR);
return aarch64_insn_encode_register(AARCH64_INSN_REGTYPE_RS, insn,
state);
}
u32 aarch64_insn_gen_ldadd(enum aarch64_insn_register result,
enum aarch64_insn_register address,
enum aarch64_insn_register value,
enum aarch64_insn_size_type size)
{
u32 insn = aarch64_insn_get_ldadd_value();
switch (size) {
case AARCH64_INSN_SIZE_32:
case AARCH64_INSN_SIZE_64:
break;
default:
pr_err("%s: unimplemented size encoding %d\n", __func__, size);
return AARCH64_BREAK_FAULT;
}
insn = aarch64_insn_encode_ldst_size(size, insn);
insn = aarch64_insn_encode_register(AARCH64_INSN_REGTYPE_RT, insn,
result);
insn = aarch64_insn_encode_register(AARCH64_INSN_REGTYPE_RN, insn,
address);
return aarch64_insn_encode_register(AARCH64_INSN_REGTYPE_RS, insn,
value);
}
u32 aarch64_insn_gen_stadd(enum aarch64_insn_register address,
enum aarch64_insn_register value,
enum aarch64_insn_size_type size)
{
/*
* STADD is simply encoded as an alias for LDADD with XZR as
* the destination register.
*/
return aarch64_insn_gen_ldadd(AARCH64_INSN_REG_ZR, address,
value, size);
}
static u32 aarch64_insn_encode_prfm_imm(enum aarch64_insn_prfm_type type,
enum aarch64_insn_prfm_target target,
enum aarch64_insn_prfm_policy policy,
u32 insn)
{
u32 imm_type = 0, imm_target = 0, imm_policy = 0;
switch (type) {
case AARCH64_INSN_PRFM_TYPE_PLD:
break;
case AARCH64_INSN_PRFM_TYPE_PLI:
imm_type = BIT(0);
break;
case AARCH64_INSN_PRFM_TYPE_PST:
imm_type = BIT(1);
break;
default:
pr_err("%s: unknown prfm type encoding %d\n", __func__, type);
return AARCH64_BREAK_FAULT;
}
switch (target) {
case AARCH64_INSN_PRFM_TARGET_L1:
break;
case AARCH64_INSN_PRFM_TARGET_L2:
imm_target = BIT(0);
break;
case AARCH64_INSN_PRFM_TARGET_L3:
imm_target = BIT(1);
break;
default:
pr_err("%s: unknown prfm target encoding %d\n", __func__, target);
return AARCH64_BREAK_FAULT;
}
switch (policy) {
case AARCH64_INSN_PRFM_POLICY_KEEP:
break;
case AARCH64_INSN_PRFM_POLICY_STRM:
imm_policy = BIT(0);
break;
default:
pr_err("%s: unknown prfm policy encoding %d\n", __func__, policy);
return AARCH64_BREAK_FAULT;
}
/* In this case, imm5 is encoded into Rt field. */
insn &= ~GENMASK(4, 0);
insn |= imm_policy | (imm_target << 1) | (imm_type << 3);
return insn;
}
u32 aarch64_insn_gen_prefetch(enum aarch64_insn_register base,
enum aarch64_insn_prfm_type type,
enum aarch64_insn_prfm_target target,
enum aarch64_insn_prfm_policy policy)
{
u32 insn = aarch64_insn_get_prfm_value();
insn = aarch64_insn_encode_ldst_size(AARCH64_INSN_SIZE_64, insn);
insn = aarch64_insn_encode_prfm_imm(type, target, policy, insn);
insn = aarch64_insn_encode_register(AARCH64_INSN_REGTYPE_RN, insn,
base);
return aarch64_insn_encode_immediate(AARCH64_INSN_IMM_12, insn, 0);
}
u32 aarch64_insn_gen_add_sub_imm(enum aarch64_insn_register dst,
enum aarch64_insn_register src,
int imm, enum aarch64_insn_variant variant,
enum aarch64_insn_adsb_type type)
{
u32 insn;
switch (type) {
case AARCH64_INSN_ADSB_ADD:
insn = aarch64_insn_get_add_imm_value();
break;
case AARCH64_INSN_ADSB_SUB:
insn = aarch64_insn_get_sub_imm_value();
break;
case AARCH64_INSN_ADSB_ADD_SETFLAGS:
insn = aarch64_insn_get_adds_imm_value();
break;
case AARCH64_INSN_ADSB_SUB_SETFLAGS:
insn = aarch64_insn_get_subs_imm_value();
break;
default:
pr_err("%s: unknown add/sub encoding %d\n", __func__, type);
return AARCH64_BREAK_FAULT;
}
switch (variant) {
case AARCH64_INSN_VARIANT_32BIT:
break;
case AARCH64_INSN_VARIANT_64BIT:
insn |= AARCH64_INSN_SF_BIT;
break;
default:
pr_err("%s: unknown variant encoding %d\n", __func__, variant);
return AARCH64_BREAK_FAULT;
}
/* We can't encode more than a 24bit value (12bit + 12bit shift) */
if (imm & ~(BIT(24) - 1))
goto out;
/* If we have something in the top 12 bits... */
if (imm & ~(SZ_4K - 1)) {
/* ... and in the low 12 bits -> error */
if (imm & (SZ_4K - 1))
goto out;
imm >>= 12;
insn |= AARCH64_INSN_LSL_12;
}
insn = aarch64_insn_encode_register(AARCH64_INSN_REGTYPE_RD, insn, dst);
insn = aarch64_insn_encode_register(AARCH64_INSN_REGTYPE_RN, insn, src);
return aarch64_insn_encode_immediate(AARCH64_INSN_IMM_12, insn, imm);
out:
pr_err("%s: invalid immediate encoding %d\n", __func__, imm);
return AARCH64_BREAK_FAULT;
}
u32 aarch64_insn_gen_bitfield(enum aarch64_insn_register dst,
enum aarch64_insn_register src,
int immr, int imms,
enum aarch64_insn_variant variant,
enum aarch64_insn_bitfield_type type)
{
u32 insn;
u32 mask;
switch (type) {
case AARCH64_INSN_BITFIELD_MOVE:
insn = aarch64_insn_get_bfm_value();
break;
case AARCH64_INSN_BITFIELD_MOVE_UNSIGNED:
insn = aarch64_insn_get_ubfm_value();
break;
case AARCH64_INSN_BITFIELD_MOVE_SIGNED:
insn = aarch64_insn_get_sbfm_value();
break;
default:
pr_err("%s: unknown bitfield encoding %d\n", __func__, type);
return AARCH64_BREAK_FAULT;
}
switch (variant) {
case AARCH64_INSN_VARIANT_32BIT:
mask = GENMASK(4, 0);
break;
case AARCH64_INSN_VARIANT_64BIT:
insn |= AARCH64_INSN_SF_BIT | AARCH64_INSN_N_BIT;
mask = GENMASK(5, 0);
break;
default:
pr_err("%s: unknown variant encoding %d\n", __func__, variant);
return AARCH64_BREAK_FAULT;
}
if (immr & ~mask) {
pr_err("%s: invalid immr encoding %d\n", __func__, immr);
return AARCH64_BREAK_FAULT;
}
if (imms & ~mask) {
pr_err("%s: invalid imms encoding %d\n", __func__, imms);
return AARCH64_BREAK_FAULT;
}
insn = aarch64_insn_encode_register(AARCH64_INSN_REGTYPE_RD, insn, dst);
insn = aarch64_insn_encode_register(AARCH64_INSN_REGTYPE_RN, insn, src);
insn = aarch64_insn_encode_immediate(AARCH64_INSN_IMM_R, insn, immr);
return aarch64_insn_encode_immediate(AARCH64_INSN_IMM_S, insn, imms);
}
u32 aarch64_insn_gen_movewide(enum aarch64_insn_register dst,
int imm, int shift,
enum aarch64_insn_variant variant,
enum aarch64_insn_movewide_type type)
{
u32 insn;
switch (type) {
case AARCH64_INSN_MOVEWIDE_ZERO:
insn = aarch64_insn_get_movz_value();
break;
case AARCH64_INSN_MOVEWIDE_KEEP:
insn = aarch64_insn_get_movk_value();
break;
case AARCH64_INSN_MOVEWIDE_INVERSE:
insn = aarch64_insn_get_movn_value();
break;
default:
pr_err("%s: unknown movewide encoding %d\n", __func__, type);
return AARCH64_BREAK_FAULT;
}
if (imm & ~(SZ_64K - 1)) {
pr_err("%s: invalid immediate encoding %d\n", __func__, imm);
return AARCH64_BREAK_FAULT;
}
switch (variant) {
case AARCH64_INSN_VARIANT_32BIT:
if (shift != 0 && shift != 16) {
pr_err("%s: invalid shift encoding %d\n", __func__,
shift);
return AARCH64_BREAK_FAULT;
}
break;
case AARCH64_INSN_VARIANT_64BIT:
insn |= AARCH64_INSN_SF_BIT;
if (shift != 0 && shift != 16 && shift != 32 && shift != 48) {
pr_err("%s: invalid shift encoding %d\n", __func__,
shift);
return AARCH64_BREAK_FAULT;
}
break;
default:
pr_err("%s: unknown variant encoding %d\n", __func__, variant);
return AARCH64_BREAK_FAULT;
}
insn |= (shift >> 4) << 21;
insn = aarch64_insn_encode_register(AARCH64_INSN_REGTYPE_RD, insn, dst);
return aarch64_insn_encode_immediate(AARCH64_INSN_IMM_16, insn, imm);
}
u32 aarch64_insn_gen_add_sub_shifted_reg(enum aarch64_insn_register dst,
enum aarch64_insn_register src,
enum aarch64_insn_register reg,
int shift,
enum aarch64_insn_variant variant,
enum aarch64_insn_adsb_type type)
{
u32 insn;
switch (type) {
case AARCH64_INSN_ADSB_ADD:
insn = aarch64_insn_get_add_value();
break;
case AARCH64_INSN_ADSB_SUB:
insn = aarch64_insn_get_sub_value();
break;
case AARCH64_INSN_ADSB_ADD_SETFLAGS:
insn = aarch64_insn_get_adds_value();
break;
case AARCH64_INSN_ADSB_SUB_SETFLAGS:
insn = aarch64_insn_get_subs_value();
break;
default:
pr_err("%s: unknown add/sub encoding %d\n", __func__, type);
return AARCH64_BREAK_FAULT;
}
switch (variant) {
case AARCH64_INSN_VARIANT_32BIT:
if (shift & ~(SZ_32 - 1)) {
pr_err("%s: invalid shift encoding %d\n", __func__,
shift);
return AARCH64_BREAK_FAULT;
}
break;
case AARCH64_INSN_VARIANT_64BIT:
insn |= AARCH64_INSN_SF_BIT;
if (shift & ~(SZ_64 - 1)) {
pr_err("%s: invalid shift encoding %d\n", __func__,
shift);
return AARCH64_BREAK_FAULT;
}
break;
default:
pr_err("%s: unknown variant encoding %d\n", __func__, variant);
return AARCH64_BREAK_FAULT;
}
insn = aarch64_insn_encode_register(AARCH64_INSN_REGTYPE_RD, insn, dst);
insn = aarch64_insn_encode_register(AARCH64_INSN_REGTYPE_RN, insn, src);
insn = aarch64_insn_encode_register(AARCH64_INSN_REGTYPE_RM, insn, reg);
return aarch64_insn_encode_immediate(AARCH64_INSN_IMM_6, insn, shift);
}
u32 aarch64_insn_gen_data1(enum aarch64_insn_register dst,
enum aarch64_insn_register src,
enum aarch64_insn_variant variant,
enum aarch64_insn_data1_type type)
{
u32 insn;
switch (type) {
case AARCH64_INSN_DATA1_REVERSE_16:
insn = aarch64_insn_get_rev16_value();
break;
case AARCH64_INSN_DATA1_REVERSE_32:
insn = aarch64_insn_get_rev32_value();
break;
case AARCH64_INSN_DATA1_REVERSE_64:
if (variant != AARCH64_INSN_VARIANT_64BIT) {
pr_err("%s: invalid variant for reverse64 %d\n",
__func__, variant);
return AARCH64_BREAK_FAULT;
}
insn = aarch64_insn_get_rev64_value();
break;
default:
pr_err("%s: unknown data1 encoding %d\n", __func__, type);
return AARCH64_BREAK_FAULT;
}
switch (variant) {
case AARCH64_INSN_VARIANT_32BIT:
break;
case AARCH64_INSN_VARIANT_64BIT:
insn |= AARCH64_INSN_SF_BIT;
break;
default:
pr_err("%s: unknown variant encoding %d\n", __func__, variant);
return AARCH64_BREAK_FAULT;
}
insn = aarch64_insn_encode_register(AARCH64_INSN_REGTYPE_RD, insn, dst);
return aarch64_insn_encode_register(AARCH64_INSN_REGTYPE_RN, insn, src);
}
u32 aarch64_insn_gen_data2(enum aarch64_insn_register dst,
enum aarch64_insn_register src,
enum aarch64_insn_register reg,
enum aarch64_insn_variant variant,
enum aarch64_insn_data2_type type)
{
u32 insn;
switch (type) {
case AARCH64_INSN_DATA2_UDIV:
insn = aarch64_insn_get_udiv_value();
break;
case AARCH64_INSN_DATA2_SDIV:
insn = aarch64_insn_get_sdiv_value();
break;
case AARCH64_INSN_DATA2_LSLV:
insn = aarch64_insn_get_lslv_value();
break;
case AARCH64_INSN_DATA2_LSRV:
insn = aarch64_insn_get_lsrv_value();
break;
case AARCH64_INSN_DATA2_ASRV:
insn = aarch64_insn_get_asrv_value();
break;
case AARCH64_INSN_DATA2_RORV:
insn = aarch64_insn_get_rorv_value();
break;
default:
pr_err("%s: unknown data2 encoding %d\n", __func__, type);
return AARCH64_BREAK_FAULT;
}
switch (variant) {
case AARCH64_INSN_VARIANT_32BIT:
break;
case AARCH64_INSN_VARIANT_64BIT:
insn |= AARCH64_INSN_SF_BIT;
break;
default:
pr_err("%s: unknown variant encoding %d\n", __func__, variant);
return AARCH64_BREAK_FAULT;
}
insn = aarch64_insn_encode_register(AARCH64_INSN_REGTYPE_RD, insn, dst);
insn = aarch64_insn_encode_register(AARCH64_INSN_REGTYPE_RN, insn, src);
return aarch64_insn_encode_register(AARCH64_INSN_REGTYPE_RM, insn, reg);
}
u32 aarch64_insn_gen_data3(enum aarch64_insn_register dst,
enum aarch64_insn_register src,
enum aarch64_insn_register reg1,
enum aarch64_insn_register reg2,
enum aarch64_insn_variant variant,
enum aarch64_insn_data3_type type)
{
u32 insn;
switch (type) {
case AARCH64_INSN_DATA3_MADD:
insn = aarch64_insn_get_madd_value();
break;
case AARCH64_INSN_DATA3_MSUB:
insn = aarch64_insn_get_msub_value();
break;
default:
pr_err("%s: unknown data3 encoding %d\n", __func__, type);
return AARCH64_BREAK_FAULT;
}
switch (variant) {
case AARCH64_INSN_VARIANT_32BIT:
break;
case AARCH64_INSN_VARIANT_64BIT:
insn |= AARCH64_INSN_SF_BIT;
break;
default:
pr_err("%s: unknown variant encoding %d\n", __func__, variant);
return AARCH64_BREAK_FAULT;
}
insn = aarch64_insn_encode_register(AARCH64_INSN_REGTYPE_RD, insn, dst);
insn = aarch64_insn_encode_register(AARCH64_INSN_REGTYPE_RA, insn, src);
insn = aarch64_insn_encode_register(AARCH64_INSN_REGTYPE_RN, insn,
reg1);
return aarch64_insn_encode_register(AARCH64_INSN_REGTYPE_RM, insn,
reg2);
}
u32 aarch64_insn_gen_logical_shifted_reg(enum aarch64_insn_register dst,
enum aarch64_insn_register src,
enum aarch64_insn_register reg,
int shift,
enum aarch64_insn_variant variant,
enum aarch64_insn_logic_type type)
{
u32 insn;
switch (type) {
case AARCH64_INSN_LOGIC_AND:
insn = aarch64_insn_get_and_value();
break;
case AARCH64_INSN_LOGIC_BIC:
insn = aarch64_insn_get_bic_value();
break;
case AARCH64_INSN_LOGIC_ORR:
insn = aarch64_insn_get_orr_value();
break;
case AARCH64_INSN_LOGIC_ORN:
insn = aarch64_insn_get_orn_value();
break;
case AARCH64_INSN_LOGIC_EOR:
insn = aarch64_insn_get_eor_value();
break;
case AARCH64_INSN_LOGIC_EON:
insn = aarch64_insn_get_eon_value();
break;
case AARCH64_INSN_LOGIC_AND_SETFLAGS:
insn = aarch64_insn_get_ands_value();
break;
case AARCH64_INSN_LOGIC_BIC_SETFLAGS:
insn = aarch64_insn_get_bics_value();
break;
default:
pr_err("%s: unknown logical encoding %d\n", __func__, type);
return AARCH64_BREAK_FAULT;
}
switch (variant) {
case AARCH64_INSN_VARIANT_32BIT:
if (shift & ~(SZ_32 - 1)) {
pr_err("%s: invalid shift encoding %d\n", __func__,
shift);
return AARCH64_BREAK_FAULT;
}
break;
case AARCH64_INSN_VARIANT_64BIT:
insn |= AARCH64_INSN_SF_BIT;
if (shift & ~(SZ_64 - 1)) {
pr_err("%s: invalid shift encoding %d\n", __func__,
shift);
return AARCH64_BREAK_FAULT;
}
break;
default:
pr_err("%s: unknown variant encoding %d\n", __func__, variant);
return AARCH64_BREAK_FAULT;
}
insn = aarch64_insn_encode_register(AARCH64_INSN_REGTYPE_RD, insn, dst);
insn = aarch64_insn_encode_register(AARCH64_INSN_REGTYPE_RN, insn, src);
insn = aarch64_insn_encode_register(AARCH64_INSN_REGTYPE_RM, insn, reg);
return aarch64_insn_encode_immediate(AARCH64_INSN_IMM_6, insn, shift);
}
u32 aarch64_insn_gen_adr(unsigned long pc, unsigned long addr,
enum aarch64_insn_register reg,
enum aarch64_insn_adr_type type)
{
u32 insn;
s32 offset;
switch (type) {
case AARCH64_INSN_ADR_TYPE_ADR:
insn = aarch64_insn_get_adr_value();
offset = addr - pc;
break;
case AARCH64_INSN_ADR_TYPE_ADRP:
insn = aarch64_insn_get_adrp_value();
offset = (addr - ALIGN_DOWN(pc, SZ_4K)) >> 12;
break;
default:
pr_err("%s: unknown adr encoding %d\n", __func__, type);
return AARCH64_BREAK_FAULT;
}
if (offset < -SZ_1M || offset >= SZ_1M)
return AARCH64_BREAK_FAULT;
insn = aarch64_insn_encode_register(AARCH64_INSN_REGTYPE_RD, insn, reg);
return aarch64_insn_encode_immediate(AARCH64_INSN_IMM_ADR, insn, offset);
}
/*
* Decode the imm field of a branch, and return the byte offset as a
* signed value (so it can be used when computing a new branch
* target).
*/
s32 aarch64_get_branch_offset(u32 insn)
{
s32 imm;
if (aarch64_insn_is_b(insn) || aarch64_insn_is_bl(insn)) {
imm = aarch64_insn_decode_immediate(AARCH64_INSN_IMM_26, insn);
return (imm << 6) >> 4;
}
if (aarch64_insn_is_cbz(insn) || aarch64_insn_is_cbnz(insn) ||
aarch64_insn_is_bcond(insn)) {
imm = aarch64_insn_decode_immediate(AARCH64_INSN_IMM_19, insn);
return (imm << 13) >> 11;
}
if (aarch64_insn_is_tbz(insn) || aarch64_insn_is_tbnz(insn)) {
imm = aarch64_insn_decode_immediate(AARCH64_INSN_IMM_14, insn);
return (imm << 18) >> 16;
}
/* Unhandled instruction */
BUG();
}
/*
* Encode the displacement of a branch in the imm field and return the
* updated instruction.
*/
u32 aarch64_set_branch_offset(u32 insn, s32 offset)
{
if (aarch64_insn_is_b(insn) || aarch64_insn_is_bl(insn))
return aarch64_insn_encode_immediate(AARCH64_INSN_IMM_26, insn,
offset >> 2);
if (aarch64_insn_is_cbz(insn) || aarch64_insn_is_cbnz(insn) ||
aarch64_insn_is_bcond(insn))
return aarch64_insn_encode_immediate(AARCH64_INSN_IMM_19, insn,
offset >> 2);
if (aarch64_insn_is_tbz(insn) || aarch64_insn_is_tbnz(insn))
return aarch64_insn_encode_immediate(AARCH64_INSN_IMM_14, insn,
offset >> 2);
/* Unhandled instruction */
BUG();
}
s32 aarch64_insn_adrp_get_offset(u32 insn)
{
BUG_ON(!aarch64_insn_is_adrp(insn));
return aarch64_insn_decode_immediate(AARCH64_INSN_IMM_ADR, insn) << 12;
}
u32 aarch64_insn_adrp_set_offset(u32 insn, s32 offset)
{
BUG_ON(!aarch64_insn_is_adrp(insn));
return aarch64_insn_encode_immediate(AARCH64_INSN_IMM_ADR, insn,
offset >> 12);
}
/*
* Extract the Op/CR data from a msr/mrs instruction.
*/
u32 aarch64_insn_extract_system_reg(u32 insn)
{
return (insn & 0x1FFFE0) >> 5;
}
bool aarch32_insn_is_wide(u32 insn)
{
return insn >= 0xe800;
}
/*
* Macros/defines for extracting register numbers from instruction.
*/
u32 aarch32_insn_extract_reg_num(u32 insn, int offset)
{
return (insn & (0xf << offset)) >> offset;
}
#define OPC2_MASK 0x7
#define OPC2_OFFSET 5
u32 aarch32_insn_mcr_extract_opc2(u32 insn)
{
return (insn & (OPC2_MASK << OPC2_OFFSET)) >> OPC2_OFFSET;
}
#define CRM_MASK 0xf
u32 aarch32_insn_mcr_extract_crm(u32 insn)
{
return insn & CRM_MASK;
}
static bool __kprobes __check_eq(unsigned long pstate)
{
return (pstate & PSR_Z_BIT) != 0;
}
static bool __kprobes __check_ne(unsigned long pstate)
{
return (pstate & PSR_Z_BIT) == 0;
}
static bool __kprobes __check_cs(unsigned long pstate)
{
return (pstate & PSR_C_BIT) != 0;
}
static bool __kprobes __check_cc(unsigned long pstate)
{
return (pstate & PSR_C_BIT) == 0;
}
static bool __kprobes __check_mi(unsigned long pstate)
{
return (pstate & PSR_N_BIT) != 0;
}
static bool __kprobes __check_pl(unsigned long pstate)
{
return (pstate & PSR_N_BIT) == 0;
}
static bool __kprobes __check_vs(unsigned long pstate)
{
return (pstate & PSR_V_BIT) != 0;
}
static bool __kprobes __check_vc(unsigned long pstate)
{
return (pstate & PSR_V_BIT) == 0;
}
static bool __kprobes __check_hi(unsigned long pstate)
{
pstate &= ~(pstate >> 1); /* PSR_C_BIT &= ~PSR_Z_BIT */
return (pstate & PSR_C_BIT) != 0;
}
static bool __kprobes __check_ls(unsigned long pstate)
{
pstate &= ~(pstate >> 1); /* PSR_C_BIT &= ~PSR_Z_BIT */
return (pstate & PSR_C_BIT) == 0;
}
static bool __kprobes __check_ge(unsigned long pstate)
{
pstate ^= (pstate << 3); /* PSR_N_BIT ^= PSR_V_BIT */
return (pstate & PSR_N_BIT) == 0;
}
static bool __kprobes __check_lt(unsigned long pstate)
{
pstate ^= (pstate << 3); /* PSR_N_BIT ^= PSR_V_BIT */
return (pstate & PSR_N_BIT) != 0;
}
static bool __kprobes __check_gt(unsigned long pstate)
{
/*PSR_N_BIT ^= PSR_V_BIT */
unsigned long temp = pstate ^ (pstate << 3);
temp |= (pstate << 1); /*PSR_N_BIT |= PSR_Z_BIT */
return (temp & PSR_N_BIT) == 0;
}
static bool __kprobes __check_le(unsigned long pstate)
{
/*PSR_N_BIT ^= PSR_V_BIT */
unsigned long temp = pstate ^ (pstate << 3);
temp |= (pstate << 1); /*PSR_N_BIT |= PSR_Z_BIT */
return (temp & PSR_N_BIT) != 0;
}
static bool __kprobes __check_al(unsigned long pstate)
{
return true;
}
/*
* Note that the ARMv8 ARM calls condition code 0b1111 "nv", but states that
* it behaves identically to 0b1110 ("al").
*/
pstate_check_t * const aarch32_opcode_cond_checks[16] = {
__check_eq, __check_ne, __check_cs, __check_cc,
__check_mi, __check_pl, __check_vs, __check_vc,
__check_hi, __check_ls, __check_ge, __check_lt,
__check_gt, __check_le, __check_al, __check_al
};
static bool range_of_ones(u64 val)
{
/* Doesn't handle full ones or full zeroes */
u64 sval = val >> __ffs64(val);
/* One of Sean Eron Anderson's bithack tricks */
return ((sval + 1) & (sval)) == 0;
}
static u32 aarch64_encode_immediate(u64 imm,
enum aarch64_insn_variant variant,
u32 insn)
{
unsigned int immr, imms, n, ones, ror, esz, tmp;
u64 mask;
switch (variant) {
case AARCH64_INSN_VARIANT_32BIT:
esz = 32;
break;
case AARCH64_INSN_VARIANT_64BIT:
insn |= AARCH64_INSN_SF_BIT;
esz = 64;
break;
default:
pr_err("%s: unknown variant encoding %d\n", __func__, variant);
return AARCH64_BREAK_FAULT;
}
mask = GENMASK(esz - 1, 0);
/* Can't encode full zeroes, full ones, or value wider than the mask */
if (!imm || imm == mask || imm & ~mask)
return AARCH64_BREAK_FAULT;
/*
* Inverse of Replicate(). Try to spot a repeating pattern
* with a pow2 stride.
*/
for (tmp = esz / 2; tmp >= 2; tmp /= 2) {
u64 emask = BIT(tmp) - 1;
if ((imm & emask) != ((imm >> tmp) & emask))
break;
esz = tmp;
mask = emask;
}
/* N is only set if we're encoding a 64bit value */
n = esz == 64;
/* Trim imm to the element size */
imm &= mask;
/* That's how many ones we need to encode */
ones = hweight64(imm);
/*
* imms is set to (ones - 1), prefixed with a string of ones
* and a zero if they fit. Cap it to 6 bits.
*/
imms = ones - 1;
imms |= 0xf << ffs(esz);
imms &= BIT(6) - 1;
/* Compute the rotation */
if (range_of_ones(imm)) {
/*
* Pattern: 0..01..10..0
*
* Compute how many rotate we need to align it right
*/
ror = __ffs64(imm);
} else {
/*
* Pattern: 0..01..10..01..1
*
* Fill the unused top bits with ones, and check if
* the result is a valid immediate (all ones with a
* contiguous ranges of zeroes).
*/
imm |= ~mask;
if (!range_of_ones(~imm))
return AARCH64_BREAK_FAULT;
/*
* Compute the rotation to get a continuous set of
* ones, with the first bit set at position 0
*/
ror = fls(~imm);
}
/*
* immr is the number of bits we need to rotate back to the
* original set of ones. Note that this is relative to the
* element size...
*/
immr = (esz - ror) % esz;
insn = aarch64_insn_encode_immediate(AARCH64_INSN_IMM_N, insn, n);
insn = aarch64_insn_encode_immediate(AARCH64_INSN_IMM_R, insn, immr);
return aarch64_insn_encode_immediate(AARCH64_INSN_IMM_S, insn, imms);
}
u32 aarch64_insn_gen_logical_immediate(enum aarch64_insn_logic_type type,
enum aarch64_insn_variant variant,
enum aarch64_insn_register Rn,
enum aarch64_insn_register Rd,
u64 imm)
{
u32 insn;
switch (type) {
case AARCH64_INSN_LOGIC_AND:
insn = aarch64_insn_get_and_imm_value();
break;
case AARCH64_INSN_LOGIC_ORR:
insn = aarch64_insn_get_orr_imm_value();
break;
case AARCH64_INSN_LOGIC_EOR:
insn = aarch64_insn_get_eor_imm_value();
break;
case AARCH64_INSN_LOGIC_AND_SETFLAGS:
insn = aarch64_insn_get_ands_imm_value();
break;
default:
pr_err("%s: unknown logical encoding %d\n", __func__, type);
return AARCH64_BREAK_FAULT;
}
insn = aarch64_insn_encode_register(AARCH64_INSN_REGTYPE_RD, insn, Rd);
insn = aarch64_insn_encode_register(AARCH64_INSN_REGTYPE_RN, insn, Rn);
return aarch64_encode_immediate(imm, variant, insn);
}
u32 aarch64_insn_gen_extr(enum aarch64_insn_variant variant,
enum aarch64_insn_register Rm,
enum aarch64_insn_register Rn,
enum aarch64_insn_register Rd,
u8 lsb)
{
u32 insn;
insn = aarch64_insn_get_extr_value();
switch (variant) {
case AARCH64_INSN_VARIANT_32BIT:
if (lsb > 31)
return AARCH64_BREAK_FAULT;
break;
case AARCH64_INSN_VARIANT_64BIT:
if (lsb > 63)
return AARCH64_BREAK_FAULT;
insn |= AARCH64_INSN_SF_BIT;
insn = aarch64_insn_encode_immediate(AARCH64_INSN_IMM_N, insn, 1);
break;
default:
pr_err("%s: unknown variant encoding %d\n", __func__, variant);
return AARCH64_BREAK_FAULT;
}
insn = aarch64_insn_encode_immediate(AARCH64_INSN_IMM_S, insn, lsb);
insn = aarch64_insn_encode_register(AARCH64_INSN_REGTYPE_RD, insn, Rd);
insn = aarch64_insn_encode_register(AARCH64_INSN_REGTYPE_RN, insn, Rn);
return aarch64_insn_encode_register(AARCH64_INSN_REGTYPE_RM, insn, Rm);
}