Message-Id: <1388996536-27014-2-git-send-email-ard.biesheuvel@linaro.org>
Date:	Mon,  6 Jan 2014 09:22:09 +0100
From:	Ard Biesheuvel <ard.biesheuvel@...aro.org>
To:	catalin.marinas@....com, will.deacon@....com,
	gregkh@...uxfoundation.org, akpm@...ux-foundation.org,
	hpa@...or.com, ak@...ux.intel.com
Cc:	linux-arm-kernel@...ts.infradead.org, linux-kernel@...r.kernel.org,
	herbert@...dor.apana.org.au, mingo@...hat.com, nico@...aro.org,
	x86@...nel.org, Ard Biesheuvel <ard.biesheuvel@...aro.org>
Subject: [PATCH 1/8] arm64: add kernel emulation for AES instructions

NOTE: this patch is not intended for merging upstream, but is only
included as a bonus so mere mortals (i.e., those whose ARMv8 system
does not support the AES crypto instructions) can test the series
if they like.

Signed-off-by: Ard Biesheuvel <ard.biesheuvel@...aro.org>
---
 arch/arm64/Makefile            |   1 +
 arch/arm64/emu/Makefile        |  11 ++
 arch/arm64/emu/ce-aes.c        | 331 +++++++++++++++++++++++++++++++++++++++++
 arch/arm64/include/asm/traps.h |  10 ++
 arch/arm64/kernel/entry.S      |   4 +-
 arch/arm64/kernel/traps.c      |  49 ++++++
 6 files changed, 405 insertions(+), 1 deletion(-)
 create mode 100644 arch/arm64/emu/Makefile
 create mode 100644 arch/arm64/emu/ce-aes.c

diff --git a/arch/arm64/Makefile b/arch/arm64/Makefile
index 2fceb71ac3b7..e0b75464b7f1 100644
--- a/arch/arm64/Makefile
+++ b/arch/arm64/Makefile
@@ -42,6 +42,7 @@ TEXT_OFFSET := 0x00080000
 
 export	TEXT_OFFSET GZFLAGS
 
+core-y		+= arch/arm64/emu/
 core-y		+= arch/arm64/kernel/ arch/arm64/mm/
 core-$(CONFIG_KVM) += arch/arm64/kvm/
 core-$(CONFIG_XEN) += arch/arm64/xen/
diff --git a/arch/arm64/emu/Makefile b/arch/arm64/emu/Makefile
new file mode 100644
index 000000000000..224b4e19ff6f
--- /dev/null
+++ b/arch/arm64/emu/Makefile
@@ -0,0 +1,11 @@
+#
+# linux/arch/arm64/emu/Makefile
+#
+# Copyright (C) 2013 Linaro Ltd <ard.biesheuvel@...aro.org>
+#
+# 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.
+#
+
+obj-y += ce-aes.o
diff --git a/arch/arm64/emu/ce-aes.c b/arch/arm64/emu/ce-aes.c
new file mode 100644
index 000000000000..d50fadbd7336
--- /dev/null
+++ b/arch/arm64/emu/ce-aes.c
@@ -0,0 +1,331 @@
+/*
+ * ce-aes.c - emulate aese/aesd/aesmc/aesimc instructions
+ *
+ * Copyright (C) 2013 Linaro Ltd <ard.biesheuvel@...aro.org>
+ *
+ * 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/init.h>
+#include <linux/printk.h>
+#include <linux/ptrace.h>
+#include <linux/types.h>
+#include <linux/uaccess.h>
+#include <asm/traps.h>
+#include <asm/hwcap.h>
+
+union AES_STATE {
+	u8	bytes[16];
+	u32	cols[4];
+	u64	l[2];
+} __aligned(8);
+
+static void add_sub_shift(union AES_STATE *st, union AES_STATE *rk, int inv);
+static void mix_columns(union AES_STATE *out, union AES_STATE *in, int inv);
+
+#define REG_ACCESS(op, r, mem) \
+	do { case r: asm(#op " {v" #r ".16b}, [%0]" : : "r"(mem)); goto out; \
+	} while (0)
+
+#define REG_SWITCH(reg, op, m) do { switch (reg) { \
+	REG_ACCESS(op,  0, m);	REG_ACCESS(op,  1, m);	REG_ACCESS(op,  2, m); \
+	REG_ACCESS(op,  3, m);	REG_ACCESS(op,  4, m);	REG_ACCESS(op,  5, m); \
+	REG_ACCESS(op,  6, m);	REG_ACCESS(op,  7, m);	REG_ACCESS(op,  8, m); \
+	REG_ACCESS(op,  9, m);	REG_ACCESS(op, 10, m);	REG_ACCESS(op, 11, m); \
+	REG_ACCESS(op, 12, m);	REG_ACCESS(op, 13, m);	REG_ACCESS(op, 14, m); \
+	REG_ACCESS(op, 15, m);	REG_ACCESS(op, 16, m);	REG_ACCESS(op, 17, m); \
+	REG_ACCESS(op, 18, m);	REG_ACCESS(op, 19, m);	REG_ACCESS(op, 20, m); \
+	REG_ACCESS(op, 21, m);	REG_ACCESS(op, 22, m);	REG_ACCESS(op, 23, m); \
+	REG_ACCESS(op, 24, m);	REG_ACCESS(op, 25, m);	REG_ACCESS(op, 26, m); \
+	REG_ACCESS(op, 27, m);	REG_ACCESS(op, 28, m);	REG_ACCESS(op, 29, m); \
+	REG_ACCESS(op, 30, m);	REG_ACCESS(op, 31, m); \
+	} out:; } while (0)
+
+static void load_neon_reg(union AES_STATE *st, int reg)
+{
+	REG_SWITCH(reg, st1, st->bytes);
+}
+
+static void save_neon_reg(union AES_STATE *st, int reg)
+{
+	REG_SWITCH(reg, ld1, st->bytes);
+}
+
+static void aesce_do_emulate(unsigned int instr)
+{
+	enum { AESE, AESD, AESMC, AESIMC } kind = (instr >> 12) & 3;
+	int rn = (instr >> 5) & 0x1f;
+	int rd = instr & 0x1f;
+	union AES_STATE in, out;
+
+	load_neon_reg(&in, rn);
+
+	switch (kind) {
+	case AESE:
+	case AESD:
+		load_neon_reg(&out, rd);
+		add_sub_shift(&out, &in, kind & 1);
+		break;
+	case AESMC:
+	case AESIMC:
+		mix_columns(&out, &in, kind & 1);
+		break;
+	}
+	save_neon_reg(&out, rd);
+}
+
+static int aesce_emu_instr(struct pt_regs *regs, unsigned int instr);
+
+static struct undef_hook aesce_emu_uh = {
+	.instr_val	= 0x4e284800,
+	.instr_mask	= 0xffffcc00,
+	.fn		= aesce_emu_instr,
+};
+
+static int aesce_emu_instr(struct pt_regs *regs, unsigned int instr)
+{
+	do {
+		aesce_do_emulate(instr);
+		regs->pc += 4;
+		get_user(instr, (u32 __user *)regs->pc);
+	} while ((instr & aesce_emu_uh.instr_mask) == aesce_emu_uh.instr_val);
+
+	return 0;
+}
+
+static int aesce_emu_init(void)
+{
+	register_undef_hook(&aesce_emu_uh);
+	elf_hwcap |= HWCAP_AES;
+	return 0;
+}
+
+arch_initcall(aesce_emu_init);
+
+static void add_sub_shift(union AES_STATE *st, union AES_STATE *rk, int inv)
+{
+	static u8 const sbox[][256] = { {
+		0x63, 0x7c, 0x77, 0x7b, 0xf2, 0x6b, 0x6f, 0xc5,
+		0x30, 0x01, 0x67, 0x2b, 0xfe, 0xd7, 0xab, 0x76,
+		0xca, 0x82, 0xc9, 0x7d, 0xfa, 0x59, 0x47, 0xf0,
+		0xad, 0xd4, 0xa2, 0xaf, 0x9c, 0xa4, 0x72, 0xc0,
+		0xb7, 0xfd, 0x93, 0x26, 0x36, 0x3f, 0xf7, 0xcc,
+		0x34, 0xa5, 0xe5, 0xf1, 0x71, 0xd8, 0x31, 0x15,
+		0x04, 0xc7, 0x23, 0xc3, 0x18, 0x96, 0x05, 0x9a,
+		0x07, 0x12, 0x80, 0xe2, 0xeb, 0x27, 0xb2, 0x75,
+		0x09, 0x83, 0x2c, 0x1a, 0x1b, 0x6e, 0x5a, 0xa0,
+		0x52, 0x3b, 0xd6, 0xb3, 0x29, 0xe3, 0x2f, 0x84,
+		0x53, 0xd1, 0x00, 0xed, 0x20, 0xfc, 0xb1, 0x5b,
+		0x6a, 0xcb, 0xbe, 0x39, 0x4a, 0x4c, 0x58, 0xcf,
+		0xd0, 0xef, 0xaa, 0xfb, 0x43, 0x4d, 0x33, 0x85,
+		0x45, 0xf9, 0x02, 0x7f, 0x50, 0x3c, 0x9f, 0xa8,
+		0x51, 0xa3, 0x40, 0x8f, 0x92, 0x9d, 0x38, 0xf5,
+		0xbc, 0xb6, 0xda, 0x21, 0x10, 0xff, 0xf3, 0xd2,
+		0xcd, 0x0c, 0x13, 0xec, 0x5f, 0x97, 0x44, 0x17,
+		0xc4, 0xa7, 0x7e, 0x3d, 0x64, 0x5d, 0x19, 0x73,
+		0x60, 0x81, 0x4f, 0xdc, 0x22, 0x2a, 0x90, 0x88,
+		0x46, 0xee, 0xb8, 0x14, 0xde, 0x5e, 0x0b, 0xdb,
+		0xe0, 0x32, 0x3a, 0x0a, 0x49, 0x06, 0x24, 0x5c,
+		0xc2, 0xd3, 0xac, 0x62, 0x91, 0x95, 0xe4, 0x79,
+		0xe7, 0xc8, 0x37, 0x6d, 0x8d, 0xd5, 0x4e, 0xa9,
+		0x6c, 0x56, 0xf4, 0xea, 0x65, 0x7a, 0xae, 0x08,
+		0xba, 0x78, 0x25, 0x2e, 0x1c, 0xa6, 0xb4, 0xc6,
+		0xe8, 0xdd, 0x74, 0x1f, 0x4b, 0xbd, 0x8b, 0x8a,
+		0x70, 0x3e, 0xb5, 0x66, 0x48, 0x03, 0xf6, 0x0e,
+		0x61, 0x35, 0x57, 0xb9, 0x86, 0xc1, 0x1d, 0x9e,
+		0xe1, 0xf8, 0x98, 0x11, 0x69, 0xd9, 0x8e, 0x94,
+		0x9b, 0x1e, 0x87, 0xe9, 0xce, 0x55, 0x28, 0xdf,
+		0x8c, 0xa1, 0x89, 0x0d, 0xbf, 0xe6, 0x42, 0x68,
+		0x41, 0x99, 0x2d, 0x0f, 0xb0, 0x54, 0xbb, 0x16
+	}, {
+		0x52, 0x09, 0x6a, 0xd5, 0x30, 0x36, 0xa5, 0x38,
+		0xbf, 0x40, 0xa3, 0x9e, 0x81, 0xf3, 0xd7, 0xfb,
+		0x7c, 0xe3, 0x39, 0x82, 0x9b, 0x2f, 0xff, 0x87,
+		0x34, 0x8e, 0x43, 0x44, 0xc4, 0xde, 0xe9, 0xcb,
+		0x54, 0x7b, 0x94, 0x32, 0xa6, 0xc2, 0x23, 0x3d,
+		0xee, 0x4c, 0x95, 0x0b, 0x42, 0xfa, 0xc3, 0x4e,
+		0x08, 0x2e, 0xa1, 0x66, 0x28, 0xd9, 0x24, 0xb2,
+		0x76, 0x5b, 0xa2, 0x49, 0x6d, 0x8b, 0xd1, 0x25,
+		0x72, 0xf8, 0xf6, 0x64, 0x86, 0x68, 0x98, 0x16,
+		0xd4, 0xa4, 0x5c, 0xcc, 0x5d, 0x65, 0xb6, 0x92,
+		0x6c, 0x70, 0x48, 0x50, 0xfd, 0xed, 0xb9, 0xda,
+		0x5e, 0x15, 0x46, 0x57, 0xa7, 0x8d, 0x9d, 0x84,
+		0x90, 0xd8, 0xab, 0x00, 0x8c, 0xbc, 0xd3, 0x0a,
+		0xf7, 0xe4, 0x58, 0x05, 0xb8, 0xb3, 0x45, 0x06,
+		0xd0, 0x2c, 0x1e, 0x8f, 0xca, 0x3f, 0x0f, 0x02,
+		0xc1, 0xaf, 0xbd, 0x03, 0x01, 0x13, 0x8a, 0x6b,
+		0x3a, 0x91, 0x11, 0x41, 0x4f, 0x67, 0xdc, 0xea,
+		0x97, 0xf2, 0xcf, 0xce, 0xf0, 0xb4, 0xe6, 0x73,
+		0x96, 0xac, 0x74, 0x22, 0xe7, 0xad, 0x35, 0x85,
+		0xe2, 0xf9, 0x37, 0xe8, 0x1c, 0x75, 0xdf, 0x6e,
+		0x47, 0xf1, 0x1a, 0x71, 0x1d, 0x29, 0xc5, 0x89,
+		0x6f, 0xb7, 0x62, 0x0e, 0xaa, 0x18, 0xbe, 0x1b,
+		0xfc, 0x56, 0x3e, 0x4b, 0xc6, 0xd2, 0x79, 0x20,
+		0x9a, 0xdb, 0xc0, 0xfe, 0x78, 0xcd, 0x5a, 0xf4,
+		0x1f, 0xdd, 0xa8, 0x33, 0x88, 0x07, 0xc7, 0x31,
+		0xb1, 0x12, 0x10, 0x59, 0x27, 0x80, 0xec, 0x5f,
+		0x60, 0x51, 0x7f, 0xa9, 0x19, 0xb5, 0x4a, 0x0d,
+		0x2d, 0xe5, 0x7a, 0x9f, 0x93, 0xc9, 0x9c, 0xef,
+		0xa0, 0xe0, 0x3b, 0x4d, 0xae, 0x2a, 0xf5, 0xb0,
+		0xc8, 0xeb, 0xbb, 0x3c, 0x83, 0x53, 0x99, 0x61,
+		0x17, 0x2b, 0x04, 0x7e, 0xba, 0x77, 0xd6, 0x26,
+		0xe1, 0x69, 0x14, 0x63, 0x55, 0x21, 0x0c, 0x7d
+	} };
+	static u8 const permute[][16] = {
+		{ 0,  5, 10, 15, 4, 9, 14,  3, 8, 13, 2,  7, 12, 1, 6, 11 },
+		{ 0, 13, 10,  7, 4, 1, 14, 11, 8,  5, 2, 15, 12, 9, 6,  3 },
+	};
+	int i;
+
+	rk->l[0] ^= st->l[0];
+	rk->l[1] ^= st->l[1];
+
+	for (i = 0; i < 16; i++)
+		st->bytes[i] = sbox[inv][rk->bytes[permute[inv][i]]];
+}
+
+static void mix_columns(union AES_STATE *out, union AES_STATE *in, int inv)
+{
+	static u32 const mc[][256] = { {
+		0x00000000, 0x03010102, 0x06020204, 0x05030306,
+		0x0c040408, 0x0f05050a, 0x0a06060c, 0x0907070e,
+		0x18080810, 0x1b090912, 0x1e0a0a14, 0x1d0b0b16,
+		0x140c0c18, 0x170d0d1a, 0x120e0e1c, 0x110f0f1e,
+		0x30101020, 0x33111122, 0x36121224, 0x35131326,
+		0x3c141428, 0x3f15152a, 0x3a16162c, 0x3917172e,
+		0x28181830, 0x2b191932, 0x2e1a1a34, 0x2d1b1b36,
+		0x241c1c38, 0x271d1d3a, 0x221e1e3c, 0x211f1f3e,
+		0x60202040, 0x63212142, 0x66222244, 0x65232346,
+		0x6c242448, 0x6f25254a, 0x6a26264c, 0x6927274e,
+		0x78282850, 0x7b292952, 0x7e2a2a54, 0x7d2b2b56,
+		0x742c2c58, 0x772d2d5a, 0x722e2e5c, 0x712f2f5e,
+		0x50303060, 0x53313162, 0x56323264, 0x55333366,
+		0x5c343468, 0x5f35356a, 0x5a36366c, 0x5937376e,
+		0x48383870, 0x4b393972, 0x4e3a3a74, 0x4d3b3b76,
+		0x443c3c78, 0x473d3d7a, 0x423e3e7c, 0x413f3f7e,
+		0xc0404080, 0xc3414182, 0xc6424284, 0xc5434386,
+		0xcc444488, 0xcf45458a, 0xca46468c, 0xc947478e,
+		0xd8484890, 0xdb494992, 0xde4a4a94, 0xdd4b4b96,
+		0xd44c4c98, 0xd74d4d9a, 0xd24e4e9c, 0xd14f4f9e,
+		0xf05050a0, 0xf35151a2, 0xf65252a4, 0xf55353a6,
+		0xfc5454a8, 0xff5555aa, 0xfa5656ac, 0xf95757ae,
+		0xe85858b0, 0xeb5959b2, 0xee5a5ab4, 0xed5b5bb6,
+		0xe45c5cb8, 0xe75d5dba, 0xe25e5ebc, 0xe15f5fbe,
+		0xa06060c0, 0xa36161c2, 0xa66262c4, 0xa56363c6,
+		0xac6464c8, 0xaf6565ca, 0xaa6666cc, 0xa96767ce,
+		0xb86868d0, 0xbb6969d2, 0xbe6a6ad4, 0xbd6b6bd6,
+		0xb46c6cd8, 0xb76d6dda, 0xb26e6edc, 0xb16f6fde,
+		0x907070e0, 0x937171e2, 0x967272e4, 0x957373e6,
+		0x9c7474e8, 0x9f7575ea, 0x9a7676ec, 0x997777ee,
+		0x887878f0, 0x8b7979f2, 0x8e7a7af4, 0x8d7b7bf6,
+		0x847c7cf8, 0x877d7dfa, 0x827e7efc, 0x817f7ffe,
+		0x9b80801b, 0x98818119, 0x9d82821f, 0x9e83831d,
+		0x97848413, 0x94858511, 0x91868617, 0x92878715,
+		0x8388880b, 0x80898909, 0x858a8a0f, 0x868b8b0d,
+		0x8f8c8c03, 0x8c8d8d01, 0x898e8e07, 0x8a8f8f05,
+		0xab90903b, 0xa8919139, 0xad92923f, 0xae93933d,
+		0xa7949433, 0xa4959531, 0xa1969637, 0xa2979735,
+		0xb398982b, 0xb0999929, 0xb59a9a2f, 0xb69b9b2d,
+		0xbf9c9c23, 0xbc9d9d21, 0xb99e9e27, 0xba9f9f25,
+		0xfba0a05b, 0xf8a1a159, 0xfda2a25f, 0xfea3a35d,
+		0xf7a4a453, 0xf4a5a551, 0xf1a6a657, 0xf2a7a755,
+		0xe3a8a84b, 0xe0a9a949, 0xe5aaaa4f, 0xe6abab4d,
+		0xefacac43, 0xecadad41, 0xe9aeae47, 0xeaafaf45,
+		0xcbb0b07b, 0xc8b1b179, 0xcdb2b27f, 0xceb3b37d,
+		0xc7b4b473, 0xc4b5b571, 0xc1b6b677, 0xc2b7b775,
+		0xd3b8b86b, 0xd0b9b969, 0xd5baba6f, 0xd6bbbb6d,
+		0xdfbcbc63, 0xdcbdbd61, 0xd9bebe67, 0xdabfbf65,
+		0x5bc0c09b, 0x58c1c199, 0x5dc2c29f, 0x5ec3c39d,
+		0x57c4c493, 0x54c5c591, 0x51c6c697, 0x52c7c795,
+		0x43c8c88b, 0x40c9c989, 0x45caca8f, 0x46cbcb8d,
+		0x4fcccc83, 0x4ccdcd81, 0x49cece87, 0x4acfcf85,
+		0x6bd0d0bb, 0x68d1d1b9, 0x6dd2d2bf, 0x6ed3d3bd,
+		0x67d4d4b3, 0x64d5d5b1, 0x61d6d6b7, 0x62d7d7b5,
+		0x73d8d8ab, 0x70d9d9a9, 0x75dadaaf, 0x76dbdbad,
+		0x7fdcdca3, 0x7cdddda1, 0x79dedea7, 0x7adfdfa5,
+		0x3be0e0db, 0x38e1e1d9, 0x3de2e2df, 0x3ee3e3dd,
+		0x37e4e4d3, 0x34e5e5d1, 0x31e6e6d7, 0x32e7e7d5,
+		0x23e8e8cb, 0x20e9e9c9, 0x25eaeacf, 0x26ebebcd,
+		0x2fececc3, 0x2cededc1, 0x29eeeec7, 0x2aefefc5,
+		0x0bf0f0fb, 0x08f1f1f9, 0x0df2f2ff, 0x0ef3f3fd,
+		0x07f4f4f3, 0x04f5f5f1, 0x01f6f6f7, 0x02f7f7f5,
+		0x13f8f8eb, 0x10f9f9e9, 0x15fafaef, 0x16fbfbed,
+		0x1ffcfce3, 0x1cfdfde1, 0x19fefee7, 0x1affffe5,
+	}, {
+		0x00000000, 0x0b0d090e, 0x161a121c, 0x1d171b12,
+		0x2c342438, 0x27392d36, 0x3a2e3624, 0x31233f2a,
+		0x58684870, 0x5365417e, 0x4e725a6c, 0x457f5362,
+		0x745c6c48, 0x7f516546, 0x62467e54, 0x694b775a,
+		0xb0d090e0, 0xbbdd99ee, 0xa6ca82fc, 0xadc78bf2,
+		0x9ce4b4d8, 0x97e9bdd6, 0x8afea6c4, 0x81f3afca,
+		0xe8b8d890, 0xe3b5d19e, 0xfea2ca8c, 0xf5afc382,
+		0xc48cfca8, 0xcf81f5a6, 0xd296eeb4, 0xd99be7ba,
+		0x7bbb3bdb, 0x70b632d5, 0x6da129c7, 0x66ac20c9,
+		0x578f1fe3, 0x5c8216ed, 0x41950dff, 0x4a9804f1,
+		0x23d373ab, 0x28de7aa5, 0x35c961b7, 0x3ec468b9,
+		0x0fe75793, 0x04ea5e9d, 0x19fd458f, 0x12f04c81,
+		0xcb6bab3b, 0xc066a235, 0xdd71b927, 0xd67cb029,
+		0xe75f8f03, 0xec52860d, 0xf1459d1f, 0xfa489411,
+		0x9303e34b, 0x980eea45, 0x8519f157, 0x8e14f859,
+		0xbf37c773, 0xb43ace7d, 0xa92dd56f, 0xa220dc61,
+		0xf66d76ad, 0xfd607fa3, 0xe07764b1, 0xeb7a6dbf,
+		0xda595295, 0xd1545b9b, 0xcc434089, 0xc74e4987,
+		0xae053edd, 0xa50837d3, 0xb81f2cc1, 0xb31225cf,
+		0x82311ae5, 0x893c13eb, 0x942b08f9, 0x9f2601f7,
+		0x46bde64d, 0x4db0ef43, 0x50a7f451, 0x5baafd5f,
+		0x6a89c275, 0x6184cb7b, 0x7c93d069, 0x779ed967,
+		0x1ed5ae3d, 0x15d8a733, 0x08cfbc21, 0x03c2b52f,
+		0x32e18a05, 0x39ec830b, 0x24fb9819, 0x2ff69117,
+		0x8dd64d76, 0x86db4478, 0x9bcc5f6a, 0x90c15664,
+		0xa1e2694e, 0xaaef6040, 0xb7f87b52, 0xbcf5725c,
+		0xd5be0506, 0xdeb30c08, 0xc3a4171a, 0xc8a91e14,
+		0xf98a213e, 0xf2872830, 0xef903322, 0xe49d3a2c,
+		0x3d06dd96, 0x360bd498, 0x2b1ccf8a, 0x2011c684,
+		0x1132f9ae, 0x1a3ff0a0, 0x0728ebb2, 0x0c25e2bc,
+		0x656e95e6, 0x6e639ce8, 0x737487fa, 0x78798ef4,
+		0x495ab1de, 0x4257b8d0, 0x5f40a3c2, 0x544daacc,
+		0xf7daec41, 0xfcd7e54f, 0xe1c0fe5d, 0xeacdf753,
+		0xdbeec879, 0xd0e3c177, 0xcdf4da65, 0xc6f9d36b,
+		0xafb2a431, 0xa4bfad3f, 0xb9a8b62d, 0xb2a5bf23,
+		0x83868009, 0x888b8907, 0x959c9215, 0x9e919b1b,
+		0x470a7ca1, 0x4c0775af, 0x51106ebd, 0x5a1d67b3,
+		0x6b3e5899, 0x60335197, 0x7d244a85, 0x7629438b,
+		0x1f6234d1, 0x146f3ddf, 0x097826cd, 0x02752fc3,
+		0x335610e9, 0x385b19e7, 0x254c02f5, 0x2e410bfb,
+		0x8c61d79a, 0x876cde94, 0x9a7bc586, 0x9176cc88,
+		0xa055f3a2, 0xab58faac, 0xb64fe1be, 0xbd42e8b0,
+		0xd4099fea, 0xdf0496e4, 0xc2138df6, 0xc91e84f8,
+		0xf83dbbd2, 0xf330b2dc, 0xee27a9ce, 0xe52aa0c0,
+		0x3cb1477a, 0x37bc4e74, 0x2aab5566, 0x21a65c68,
+		0x10856342, 0x1b886a4c, 0x069f715e, 0x0d927850,
+		0x64d90f0a, 0x6fd40604, 0x72c31d16, 0x79ce1418,
+		0x48ed2b32, 0x43e0223c, 0x5ef7392e, 0x55fa3020,
+		0x01b79aec, 0x0aba93e2, 0x17ad88f0, 0x1ca081fe,
+		0x2d83bed4, 0x268eb7da, 0x3b99acc8, 0x3094a5c6,
+		0x59dfd29c, 0x52d2db92, 0x4fc5c080, 0x44c8c98e,
+		0x75ebf6a4, 0x7ee6ffaa, 0x63f1e4b8, 0x68fcedb6,
+		0xb1670a0c, 0xba6a0302, 0xa77d1810, 0xac70111e,
+		0x9d532e34, 0x965e273a, 0x8b493c28, 0x80443526,
+		0xe90f427c, 0xe2024b72, 0xff155060, 0xf418596e,
+		0xc53b6644, 0xce366f4a, 0xd3217458, 0xd82c7d56,
+		0x7a0ca137, 0x7101a839, 0x6c16b32b, 0x671bba25,
+		0x5638850f, 0x5d358c01, 0x40229713, 0x4b2f9e1d,
+		0x2264e947, 0x2969e049, 0x347efb5b, 0x3f73f255,
+		0x0e50cd7f, 0x055dc471, 0x184adf63, 0x1347d66d,
+		0xcadc31d7, 0xc1d138d9, 0xdcc623cb, 0xd7cb2ac5,
+		0xe6e815ef, 0xede51ce1, 0xf0f207f3, 0xfbff0efd,
+		0x92b479a7, 0x99b970a9, 0x84ae6bbb, 0x8fa362b5,
+		0xbe805d9f, 0xb58d5491, 0xa89a4f83, 0xa397468d,
+	} };
+
+	int i;
+
+	for (i = 0; i < 16; i += 4)
+		out->cols[i >> 2] = cpu_to_le32(
+			mc[inv][in->bytes[i]] ^
+			rol32(mc[inv][in->bytes[i + 1]], 8) ^
+			rol32(mc[inv][in->bytes[i + 2]], 16) ^
+			rol32(mc[inv][in->bytes[i + 3]], 24));
+}
diff --git a/arch/arm64/include/asm/traps.h b/arch/arm64/include/asm/traps.h
index 10ca8ff93cc2..781e50cb2f03 100644
--- a/arch/arm64/include/asm/traps.h
+++ b/arch/arm64/include/asm/traps.h
@@ -27,4 +27,14 @@ static inline int in_exception_text(unsigned long ptr)
 	       ptr < (unsigned long)&__exception_text_end;
 }
 
+struct undef_hook {
+	struct list_head node;
+	u32 instr_mask;
+	u32 instr_val;
+	int (*fn)(struct pt_regs *regs, unsigned int instr);
+};
+
+void register_undef_hook(struct undef_hook *hook);
+void unregister_undef_hook(struct undef_hook *hook);
+
 #endif
diff --git a/arch/arm64/kernel/entry.S b/arch/arm64/kernel/entry.S
index 32d7fe6c3d6a..7cfbb65f6aa9 100644
--- a/arch/arm64/kernel/entry.S
+++ b/arch/arm64/kernel/entry.S
@@ -283,7 +283,9 @@ el1_undef:
 	 * Undefined instruction
 	 */
 	mov	x0, sp
-	b	do_undefinstr
+	bl	do_undefinstr
+
+	kernel_exit 1
 el1_dbg:
 	/*
 	 * Debug exception handling
diff --git a/arch/arm64/kernel/traps.c b/arch/arm64/kernel/traps.c
index 7ffadddb645d..3cc4c915b73f 100644
--- a/arch/arm64/kernel/traps.c
+++ b/arch/arm64/kernel/traps.c
@@ -257,11 +257,60 @@ void arm64_notify_die(const char *str, struct pt_regs *regs,
 		die(str, regs, err);
 }
 
+static LIST_HEAD(undef_hook);
+static DEFINE_RAW_SPINLOCK(undef_lock);
+
+void register_undef_hook(struct undef_hook *hook)
+{
+	unsigned long flags;
+
+	raw_spin_lock_irqsave(&undef_lock, flags);
+	list_add(&hook->node, &undef_hook);
+	raw_spin_unlock_irqrestore(&undef_lock, flags);
+}
+
+void unregister_undef_hook(struct undef_hook *hook)
+{
+	unsigned long flags;
+
+	raw_spin_lock_irqsave(&undef_lock, flags);
+	list_del(&hook->node);
+	raw_spin_unlock_irqrestore(&undef_lock, flags);
+}
+
+static int call_undef_hook(struct pt_regs *regs, void __user *pc)
+{
+	struct undef_hook *hook;
+	unsigned long flags;
+	int (*fn)(struct pt_regs *regs, unsigned int instr) = NULL;
+	unsigned int instr;
+	mm_segment_t fs;
+	int ret;
+
+	fs = get_fs();
+	set_fs(KERNEL_DS);
+
+	get_user(instr, (u32 __user *)pc);
+
+	raw_spin_lock_irqsave(&undef_lock, flags);
+	list_for_each_entry(hook, &undef_hook, node)
+		if ((instr & hook->instr_mask) == hook->instr_val)
+			fn = hook->fn;
+	raw_spin_unlock_irqrestore(&undef_lock, flags);
+
+	ret = fn ? fn(regs, instr) : 1;
+	set_fs(fs);
+	return ret;
+}
+
 asmlinkage void __exception do_undefinstr(struct pt_regs *regs)
 {
 	siginfo_t info;
 	void __user *pc = (void __user *)instruction_pointer(regs);
 
+	if (call_undef_hook(regs, pc) == 0)
+		return;
+
 	/* check for AArch32 breakpoint instructions */
 	if (!aarch32_break_handler(regs))
 		return;
-- 
1.8.3.2

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