1/*- 2 * SPDX-License-Identifier: BSD-2-Clause 3 * 4 * Copyright (C) 2018 Turing Robotic Industries Inc. 5 * Copyright (C) 2022 Dmitry Chagin <dchagin@FreeBSD.org> 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 19 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 26 * SUCH DAMAGE. 27 */ 28 29#include <sys/elf_common.h> 30 31#include <machine/asm.h> 32#include <machine/param.h> 33#include <machine/vmparam.h> 34 35#include <sys/errno.h> 36 37#include "assym.inc" 38 39.macro check_user_access user_arg, limit, bad_addr_func 40 ldr x7, =(\limit) 41 cmp x\user_arg, x7 42 b.cs \bad_addr_func 43.endm 44 45futex_fault: 46 SET_FAULT_HANDLER(xzr, x1) 47 EXIT_USER_ACCESS_CHECK(w0, x1) 48futex_fault_nopcb: 49 mov x0, #EFAULT 50 ret 51 52#define LINUX_FUTEX_MAX_LOOPS 128 53 54/* 55 * int oparg, uint32_t *uaddr, int *oldval 56 * 57 * Return 0 on success, errno on failure, 58 * EAGAIN is returned if LL/SC operation fails. 59 * 60 * XXX. VM_MAXUSER_ADDRESS is not applicable here, should be replaced 61 * by something like LINUX_SHAREDPAGE. 62 */ 63 64/* (int *)uaddr2 = oparg */ 65ENTRY(futex_xchgl) 66 check_user_access 1, (VM_MAXUSER_ADDRESS-3), futex_fault_nopcb 67 adr x9, futex_fault /* Load the fault handler */ 68 SET_FAULT_HANDLER(x9, x4) /* And set it */ 69 ENTER_USER_ACCESS(w9, x4) 70 mov w5, #LINUX_FUTEX_MAX_LOOPS 71 prfm pstl1strm, [x1] 72 mov w6, w0 /* Save oparg */ 731: ldxr w4, [x1] /* Load oldval from uaddr */ 74 stlxr w0, w6, [x1] /* Store oparg to uaddr */ 75 cbz w0, 3f /* Exit on success */ 76 sub w5, w5, w0 /* Dec loop counter, w0 is 1 */ 77 cbnz w5, 1b /* Loop */ 78 mov x0, #EAGAIN /* Store of newval failed */ 793: dmb ish 80 EXIT_USER_ACCESS(w9) 81 SET_FAULT_HANDLER(xzr, x9) /* Reset the fault handler */ 82 str w4, [x2] /* Store oldval */ 83 ret 84END(futex_xchgl) 85 86/* (int *)uaddr2 += oparg */ 87ENTRY(futex_addl) 88 check_user_access 1, (VM_MAXUSER_ADDRESS-3), futex_fault_nopcb 89 adr x9, futex_fault 90 SET_FAULT_HANDLER(x9, x4) 91 ENTER_USER_ACCESS(w9, x4) 92 mov w5, #LINUX_FUTEX_MAX_LOOPS 93 prfm pstl1strm, [x1] 94 mov w6, w0 951: ldxr w4, [x1] 96 add w3, w4, w6 /* oldval + oparg */ 97 stlxr w0, w3, [x1] 98 cbz w0, 3f 99 sub w5, w5, w0 100 cbnz w5, 1b 101 mov x0, #EAGAIN 1023: dmb ish 103 EXIT_USER_ACCESS(w9) 104 SET_FAULT_HANDLER(xzr, x9) 105 str w4, [x2] 106 ret 107END(futex_addl) 108 109/* (int *)uaddr2 |= oparg */ 110ENTRY(futex_orl) 111 check_user_access 1, (VM_MAXUSER_ADDRESS-3), futex_fault_nopcb 112 adr x9, futex_fault 113 SET_FAULT_HANDLER(x9, x4) 114 ENTER_USER_ACCESS(w9, x4) 115 mov w5, #LINUX_FUTEX_MAX_LOOPS 116 prfm pstl1strm, [x1] 117 mov w6, w0 1181: ldxr w4, [x1] 119 orr w3, w4, w6 /* oldavl |= oparg */ 120 stlxr w0, w3, [x1] 121 cbz w0, 3f 122 sub w5, w5, w0 123 cbnz w5, 1b 124 mov x0, #EAGAIN 1253: dmb ish 126 EXIT_USER_ACCESS(w9) 127 SET_FAULT_HANDLER(xzr, x9) 128 str w4, [x2] 129 ret 130END(futex_orl) 131 132/* (int *)uaddr2 &= oparg */ 133ENTRY(futex_andl) 134 check_user_access 1, (VM_MAXUSER_ADDRESS-3), futex_fault_nopcb 135 adr x9, futex_fault 136 SET_FAULT_HANDLER(x9, x4) 137 ENTER_USER_ACCESS(w9, x4) 138 mov w5, #LINUX_FUTEX_MAX_LOOPS 139 prfm pstl1strm, [x1] 140 mov w6, w0 1411: ldxr w4, [x1] 142 and w3, w4, w6 /* oldval &= oparg */ 143 stlxr w0, w3, [x1] 144 cbz w0, 3f 145 sub w5, w5, w0 146 cbnz w5, 1b 147 mov x0, #EAGAIN 1483: dmb ish 149 EXIT_USER_ACCESS(w9) 150 SET_FAULT_HANDLER(xzr, x9) 151 str w4, [x2] 152 ret 153END(futex_andl) 154 155/* (int *)uaddr2 ^= oparg */ 156ENTRY(futex_xorl) 157 check_user_access 1, (VM_MAXUSER_ADDRESS-3), futex_fault_nopcb 158 adr x9, futex_fault 159 SET_FAULT_HANDLER(x9, x4) 160 ENTER_USER_ACCESS(w9, x4) 161 mov w5, #LINUX_FUTEX_MAX_LOOPS 162 prfm pstl1strm, [x1] 163 mov w6, w0 1641: ldxr w4, [x1] 165 eor w3, w4, w6 /* oldval ^= oparg */ 166 stlxr w0, w3, [x1] 167 cbz w0, 3f 168 sub w5, w5, w0 169 cbnz w5, 1b 170 mov x0, #EAGAIN 1713: dmb ish 172 EXIT_USER_ACCESS(w9) 173 SET_FAULT_HANDLER(xzr, x9) 174 str w4, [x2] 175 ret 176END(futex_xorl) 177 178GNU_PROPERTY_AARCH64_FEATURE_1_NOTE(GNU_PROPERTY_AARCH64_FEATURE_1_VAL) 179