1 /* $NetBSD: elf_support.h,v 1.1 2018/03/29 13:23:40 joerg Exp $ */ 2 3 /*- 4 * Copyright (c) 2000 Eduardo Horvath. 5 * Copyright (c) 2018 The NetBSD Foundation, Inc. 6 * All rights reserved. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 17 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 18 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 19 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 20 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 21 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 22 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 23 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 24 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 25 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 26 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 27 * POSSIBILITY OF SUCH DAMAGE. 28 */ 29 #ifndef _SPARC64_ELF_SUPPORT_H 30 #define _SPARC64_ELF_SUPPORT_H 31 32 #ifdef __arch64__ 33 /* 34 * Create a jump to the location `target` starting at `where`. 35 * This requires up to 6 instructions. 36 * The first instruction is written last as it replaces a branch 37 * in the PLT during lazy binding. 38 * The resulting code can trash %g1 and %g5. 39 */ 40 static inline void 41 sparc_write_branch(void *where_, void *target) 42 { 43 const unsigned int BAA = 0x30800000U; /* ba,a (offset / 4) */ 44 const unsigned int SETHI = 0x03000000U; /* sethi %hi(0), %g1 */ 45 const unsigned int JMP = 0x81c06000U; /* jmpl %g1+%lo(0), %g0 */ 46 const unsigned int OR = 0x82106000U; /* or %g1, 0, %g1 */ 47 const unsigned int XOR = 0x82186000U; /* xor %g1, 0, %g1 */ 48 const unsigned int MOV71 = 0x8213e000U; /* or %o7, 0, %g1 */ 49 const unsigned int MOV17 = 0x9e106000U; /* or %g1, 0, %o7 */ 50 const unsigned int CALL = 0x40000000U; /* call 0 */ 51 const unsigned int SLLX = 0x83287000U; /* sllx %g1, 0, %g1 */ 52 const unsigned int NEG = 0x82200001U; /* neg %g1 */ 53 const unsigned int SETHIG5 = 0x0b000000U; /* sethi %hi(0), %g5 */ 54 const unsigned int ORG5 = 0x82104005U; /* or %g1, %g5, %g1 */ 55 56 unsigned int *where = (unsigned int *)where_; 57 unsigned long value = (unsigned long)target; 58 unsigned long offset = value - (unsigned long)where; 59 60 #define HIVAL(v, s) (((v) >> (s)) & 0x003fffffU) 61 #define LOVAL(v, s) (((v) >> (s)) & 0x000003ffU) 62 if (offset + 0x800000 <= 0x7ffffc) { 63 /* Displacement is within 8MB, use a direct branch. */ 64 where[0] = BAA | ((offset >> 2) & 0x3fffff); 65 __asm volatile("iflush %0+0" : : "r" (where)); 66 return; 67 } 68 69 if (value <= 0xffffffffUL) { 70 /* 71 * The absolute address is a 32bit value. 72 * This can be encoded as: 73 * sethi %hi(value), %g1 74 * jmp %g1+%lo(value) 75 */ 76 where[1] = JMP | LOVAL(value, 0); 77 __asm volatile("iflush %0+4" : : "r" (where)); 78 where[0] = SETHI | HIVAL(value, 10); 79 __asm volatile("iflush %0+0" : : "r" (where)); 80 return; 81 } 82 83 if (value >= 0xffffffff00000000UL) { 84 /* 85 * The top 32bit address range can be encoded as: 86 * sethi %hix(addr), %g1 87 * xor %g1, %lox(addr), %g1 88 * jmp %g1 89 */ 90 where[2] = JMP; 91 where[1] = XOR | (value & 0x00003ff) | 0x1c00; 92 __asm volatile("iflush %0+4" : : "r" (where)); 93 __asm volatile("iflush %0+8" : : "r" (where)); 94 where[0] = SETHI | HIVAL(~value, 10); 95 __asm volatile("iflush %0+0" : : "r" (where)); 96 return; 97 } 98 99 if ((offset + 4) + 0x80000000UL <= 0x100000000UL) { 100 /* 101 * Displacement of the second instruction is within 102 * +-2GB. This can use a direct call instruction: 103 * mov %o7, %g1 104 * call (value - .) 105 * mov %g1, %o7 106 */ 107 where[1] = CALL | ((-(offset + 4)>> 2) & 0x3fffffffU); 108 where[2] = MOV17; 109 __asm volatile("iflush %0+4" : : "r" (where)); 110 __asm volatile("iflush %0+8" : : "r" (where)); 111 where[0] = MOV71; 112 __asm volatile("iflush %0+0" : : "r" (where)); 113 return; 114 } 115 116 if (value < 0x100000000000UL) { 117 /* 118 * The absolute address is a 44bit value. 119 * This can be encoded as: 120 * sethi %h44(addr), %g1 121 * or %g1, %m44(addr), %g1 122 * sllx %g1, 12, %g1 123 * jmp %g1+%l44(addr) 124 */ 125 where[1] = OR | (((value) >> 12) & 0x00001fff); 126 where[2] = SLLX | 12; 127 where[3] = JMP | LOVAL(value, 0); 128 __asm volatile("iflush %0+4" : : "r" (where)); 129 __asm volatile("iflush %0+8" : : "r" (where)); 130 __asm volatile("iflush %0+12" : : "r" (where)); 131 where[0] = SETHI | HIVAL(value, 22); 132 __asm volatile("iflush %0+0" : : "r" (where)); 133 return; 134 } 135 136 if (value > 0xfffff00000000000UL) { 137 /* 138 * The top 44bit address range can be encoded as: 139 * sethi %hi((-addr)>>12), %g1 140 * or %g1, %lo((-addr)>>12), %g1 141 * neg %g1 142 * sllx %g1, 12, %g1 143 * jmp %g1+(addr&0x0fff) 144 */ 145 unsigned long neg = (-value)>>12; 146 where[1] = OR | (LOVAL(neg, 0)+1); 147 where[2] = NEG; 148 where[3] = SLLX | 12; 149 where[4] = JMP | (value & 0x0fff); 150 __asm volatile("iflush %0+4" : : "r" (where)); 151 __asm volatile("iflush %0+8" : : "r" (where)); 152 __asm volatile("iflush %0+12" : : "r" (where)); 153 __asm volatile("iflush %0+16" : : "r" (where)); 154 where[0] = SETHI | HIVAL(neg, 10); 155 __asm volatile("iflush %0+0" : : "r" (where)); 156 return; 157 } 158 159 /* 160 * The general case of a 64bit address is encoded as: 161 * sethi %hh(addr), %g1 162 * sethi %lm(addr), %g5 163 * or %g1, %hm(addr), %g1 164 * sllx %g1, 32, %g1 165 * or %g1, %g5, %g1 166 * jmp %g1+%lo(addr) 167 */ 168 where[1] = SETHIG5 | HIVAL(value, 10); 169 where[2] = OR | LOVAL(value, 32); 170 where[3] = SLLX | 32; 171 where[4] = ORG5; 172 where[5] = JMP | LOVAL(value, 0); 173 __asm volatile("iflush %0+4" : : "r" (where)); 174 __asm volatile("iflush %0+8" : : "r" (where)); 175 __asm volatile("iflush %0+12" : : "r" (where)); 176 __asm volatile("iflush %0+16" : : "r" (where)); 177 __asm volatile("iflush %0+20" : : "r" (where)); 178 where[0] = SETHI | HIVAL(value, 42); 179 __asm volatile("iflush %0+0" : : "r" (where)); 180 #undef HIVAL 181 #undef LOVAL 182 } 183 #else 184 #include <sparc/elf_support.h> 185 #endif 186 #endif 187
Indexes created Fri Sep 26 08:10:20 GMT 2025