1 /*- 2 * Copyright (c) 2014 Andrew Turner 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 24 * SUCH DAMAGE. 25 * 26 * $FreeBSD$ 27 */ 28 29 #ifndef _MACHINE_ASM_H_ 30 #define _MACHINE_ASM_H_ 31 32 #undef __FBSDID 33 #if !defined(lint) && !defined(STRIP_FBSDID) 34 #define __FBSDID(s) .ident s 35 #else 36 #define __FBSDID(s) /* nothing */ 37 #endif 38 39 #define _C_LABEL(x) x 40 41 #define ENTRY(sym) \ 42 .text; .globl sym; .align 2; .type sym,#function; sym: \ 43 .cfi_startproc 44 #define EENTRY(sym) \ 45 .globl sym; sym: 46 #define END(sym) .cfi_endproc; .size sym, . - sym 47 #define EEND(sym) 48 49 #define WEAK_REFERENCE(sym, alias) \ 50 .weak alias; \ 51 .set alias,sym 52 53 #define UINT64_C(x) (x) 54 55 #if defined(PIC) 56 #define PIC_SYM(x,y) x ## @ ## y 57 #else 58 #define PIC_SYM(x,y) x 59 #endif 60 61 /* Alias for link register x30 */ 62 #define lr x30 63 64 /* 65 * Sets the trap fault handler. The exception handler will return to the 66 * address in the handler register on a data abort or the xzr register to 67 * clear the handler. The tmp parameter should be a register able to hold 68 * the temporary data. 69 */ 70 #define SET_FAULT_HANDLER(handler, tmp) \ 71 ldr tmp, [x18, #PC_CURTHREAD]; /* Load curthread */ \ 72 ldr tmp, [tmp, #TD_PCB]; /* Load the pcb */ \ 73 str handler, [tmp, #PCB_ONFAULT] /* Set the handler */ 74 75 #define ENTER_USER_ACCESS(reg, tmp) \ 76 ldr tmp, =has_pan; /* Get the addr of has_pan */ \ 77 ldr reg, [tmp]; /* Read it */ \ 78 cbz reg, 997f; /* If no PAN skip */ \ 79 .inst 0xd500409f | (0 << 8); /* Clear PAN */ \ 80 997: 81 82 #define EXIT_USER_ACCESS(reg) \ 83 cbz reg, 998f; /* If no PAN skip */ \ 84 .inst 0xd500409f | (1 << 8); /* Set PAN */ \ 85 998: 86 87 #define EXIT_USER_ACCESS_CHECK(reg, tmp) \ 88 ldr tmp, =has_pan; /* Get the addr of has_pan */ \ 89 ldr reg, [tmp]; /* Read it */ \ 90 cbz reg, 999f; /* If no PAN skip */ \ 91 .inst 0xd500409f | (1 << 8); /* Set PAN */ \ 92 999: 93 94 /* 95 * Some AArch64 CPUs speculate past an eret instruction. As the user may 96 * control the registers at this point add a speculation barrier usable on 97 * all AArch64 CPUs after the eret instruction. 98 * TODO: ARMv8.5 adds a specific instruction for this, we could use that 99 * if we know we are running on something that supports it. 100 */ 101 #define ERET \ 102 eret; \ 103 dsb sy; \ 104 isb 105 106 #endif /* _MACHINE_ASM_H_ */ 107