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 #ifdef KDTRACE_HOOKS 42 #define DTRACE_NOP nop 43 #else 44 #define DTRACE_NOP 45 #endif 46 47 #define LENTRY(sym) \ 48 .text; .align 2; .type sym,#function; sym: \ 49 .cfi_startproc; DTRACE_NOP 50 #define ENTRY(sym) \ 51 .globl sym; LENTRY(sym) 52 #define EENTRY(sym) \ 53 .globl sym; sym: 54 #define LEND(sym) .ltorg; .cfi_endproc; .size sym, . - sym 55 #define END(sym) LEND(sym) 56 #define EEND(sym) 57 58 #define WEAK_REFERENCE(sym, alias) \ 59 .weak alias; \ 60 .set alias,sym 61 62 #define UINT64_C(x) (x) 63 64 #if defined(PIC) 65 #define PIC_SYM(x,y) x ## @ ## y 66 #else 67 #define PIC_SYM(x,y) x 68 #endif 69 70 /* Alias for link register x30 */ 71 #define lr x30 72 73 /* 74 * Sets the trap fault handler. The exception handler will return to the 75 * address in the handler register on a data abort or the xzr register to 76 * clear the handler. The tmp parameter should be a register able to hold 77 * the temporary data. 78 */ 79 #define SET_FAULT_HANDLER(handler, tmp) \ 80 ldr tmp, [x18, #PC_CURTHREAD]; /* Load curthread */ \ 81 ldr tmp, [tmp, #TD_PCB]; /* Load the pcb */ \ 82 str handler, [tmp, #PCB_ONFAULT] /* Set the handler */ 83 84 #define ENTER_USER_ACCESS(reg, tmp) \ 85 ldr tmp, =has_pan; /* Get the addr of has_pan */ \ 86 ldr reg, [tmp]; /* Read it */ \ 87 cbz reg, 997f; /* If no PAN skip */ \ 88 .inst 0xd500409f | (0 << 8); /* Clear PAN */ \ 89 997: 90 91 #define EXIT_USER_ACCESS(reg) \ 92 cbz reg, 998f; /* If no PAN skip */ \ 93 .inst 0xd500409f | (1 << 8); /* Set PAN */ \ 94 998: 95 96 #define EXIT_USER_ACCESS_CHECK(reg, tmp) \ 97 ldr tmp, =has_pan; /* Get the addr of has_pan */ \ 98 ldr reg, [tmp]; /* Read it */ \ 99 cbz reg, 999f; /* If no PAN skip */ \ 100 .inst 0xd500409f | (1 << 8); /* Set PAN */ \ 101 999: 102 103 /* 104 * Some AArch64 CPUs speculate past an eret instruction. As the user may 105 * control the registers at this point add a speculation barrier usable on 106 * all AArch64 CPUs after the eret instruction. 107 * TODO: ARMv8.5 adds a specific instruction for this, we could use that 108 * if we know we are running on something that supports it. 109 */ 110 #define ERET \ 111 eret; \ 112 dsb sy; \ 113 isb 114 115 #endif /* _MACHINE_ASM_H_ */ 116