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 #ifdef __arm__ 30 #include <arm/asm.h> 31 #else /* !__arm__ */ 32 33 #ifndef _MACHINE_ASM_H_ 34 #define _MACHINE_ASM_H_ 35 36 #undef __FBSDID 37 #if !defined(lint) && !defined(STRIP_FBSDID) 38 #define __FBSDID(s) .ident s 39 #else 40 #define __FBSDID(s) /* nothing */ 41 #endif 42 43 #define _C_LABEL(x) x 44 45 #ifdef KDTRACE_HOOKS 46 #define DTRACE_NOP nop 47 #else 48 #define DTRACE_NOP 49 #endif 50 51 #define LENTRY(sym) \ 52 .text; .align 2; .type sym,#function; sym: \ 53 .cfi_startproc; DTRACE_NOP 54 #define ENTRY(sym) \ 55 .globl sym; LENTRY(sym) 56 #define EENTRY(sym) \ 57 .globl sym; .text; .align 2; .type sym,#function; sym: 58 #define LEND(sym) .ltorg; .cfi_endproc; .size sym, . - sym 59 #define END(sym) LEND(sym) 60 #define EEND(sym) 61 62 #define WEAK_REFERENCE(sym, alias) \ 63 .weak alias; \ 64 .set alias,sym 65 66 #define UINT64_C(x) (x) 67 68 #if defined(PIC) 69 #define PIC_SYM(x,y) x ## @ ## y 70 #else 71 #define PIC_SYM(x,y) x 72 #endif 73 74 /* Alias for link register x30 */ 75 #define lr x30 76 77 /* 78 * Sets the trap fault handler. The exception handler will return to the 79 * address in the handler register on a data abort or the xzr register to 80 * clear the handler. The tmp parameter should be a register able to hold 81 * the temporary data. 82 */ 83 #define SET_FAULT_HANDLER(handler, tmp) \ 84 ldr tmp, [x18, #PC_CURTHREAD]; /* Load curthread */ \ 85 ldr tmp, [tmp, #TD_PCB]; /* Load the pcb */ \ 86 str handler, [tmp, #PCB_ONFAULT] /* Set the handler */ 87 88 #define ENTER_USER_ACCESS(reg, tmp) \ 89 ldr tmp, =has_pan; /* Get the addr of has_pan */ \ 90 ldr reg, [tmp]; /* Read it */ \ 91 cbz reg, 997f; /* If no PAN skip */ \ 92 .inst 0xd500409f | (0 << 8); /* Clear PAN */ \ 93 997: 94 95 #define EXIT_USER_ACCESS(reg) \ 96 cbz reg, 998f; /* If no PAN skip */ \ 97 .inst 0xd500409f | (1 << 8); /* Set PAN */ \ 98 998: 99 100 #define EXIT_USER_ACCESS_CHECK(reg, tmp) \ 101 ldr tmp, =has_pan; /* Get the addr of has_pan */ \ 102 ldr reg, [tmp]; /* Read it */ \ 103 cbz reg, 999f; /* If no PAN skip */ \ 104 .inst 0xd500409f | (1 << 8); /* Set PAN */ \ 105 999: 106 107 /* 108 * Some AArch64 CPUs speculate past an eret instruction. As the user may 109 * control the registers at this point add a speculation barrier usable on 110 * all AArch64 CPUs after the eret instruction. 111 * TODO: ARMv8.5 adds a specific instruction for this, we could use that 112 * if we know we are running on something that supports it. 113 */ 114 #define ERET \ 115 eret; \ 116 dsb sy; \ 117 isb 118 119 #endif /* _MACHINE_ASM_H_ */ 120 121 #endif /* !__arm__ */ 122