1 /* 2 * CDDL HEADER START 3 * 4 * The contents of this file are subject to the terms of the 5 * Common Development and Distribution License (the "License"). 6 * You may not use this file except in compliance with the License. 7 * 8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE 9 * or http://www.opensolaris.org/os/licensing. 10 * See the License for the specific language governing permissions 11 * and limitations under the License. 12 * 13 * When distributing Covered Code, include this CDDL HEADER in each 14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE. 15 * If applicable, add the following below this CDDL HEADER, with the 16 * fields enclosed by brackets "[]" replaced with your own identifying 17 * information: Portions Copyright [yyyy] [name of copyright owner] 18 * 19 * CDDL HEADER END 20 */ 21 22 /* 23 * Copyright 2008 Sun Microsystems, Inc. All rights reserved. 24 * Use is subject to license terms. 25 */ 26 27 /* 28 * Copyright 2019 Joyent, Inc. 29 */ 30 31 #ifndef _SYS_ASM_LINKAGE_H 32 #define _SYS_ASM_LINKAGE_H 33 34 #include <sys/stack.h> 35 #include <sys/trap.h> 36 37 #ifdef __cplusplus 38 extern "C" { 39 #endif 40 41 #ifdef _ASM /* The remainder of this file is only for assembly files */ 42 43 /* 44 * make annoying differences in assembler syntax go away 45 */ 46 47 /* 48 * Why not use the 'data16' and 'addr16' prefixes .. well, the 49 * assembler doesn't quite believe in real mode, and thus argues with 50 * us about what we're trying to do. 51 */ 52 #define D16 .byte 0x66; 53 #define A16 .byte 0x67; 54 55 #define _CONST(const) (const) 56 #define _BITNOT(const) ~_CONST(const) 57 #define _MUL(a, b) _CONST(a * b) 58 59 /* 60 * C pointers are different sizes between i386 and amd64. 61 * These constants can be used to compute offsets into pointer arrays. 62 */ 63 #if defined(__amd64) 64 #define CLONGSHIFT 3 65 #define CLONGSIZE 8 66 #define CLONGMASK 7 67 #elif defined(__i386) 68 #define CLONGSHIFT 2 69 #define CLONGSIZE 4 70 #define CLONGMASK 3 71 #endif 72 73 /* 74 * Since we know we're either ILP32 or LP64 .. 75 */ 76 #define CPTRSHIFT CLONGSHIFT 77 #define CPTRSIZE CLONGSIZE 78 #define CPTRMASK CLONGMASK 79 80 #if CPTRSIZE != (1 << CPTRSHIFT) || CLONGSIZE != (1 << CLONGSHIFT) 81 #error "inconsistent shift constants" 82 #endif 83 84 #if CPTRMASK != (CPTRSIZE - 1) || CLONGMASK != (CLONGSIZE - 1) 85 #error "inconsistent mask constants" 86 #endif 87 88 #define ASM_ENTRY_ALIGN 16 89 90 /* 91 * SSE register alignment and save areas 92 */ 93 94 #define XMM_SIZE 16 95 #define XMM_ALIGN 16 96 97 #if defined(__amd64) 98 99 #define SAVE_XMM_PROLOG(sreg, nreg) \ 100 subq $_CONST(_MUL(XMM_SIZE, nreg)), %rsp; \ 101 movq %rsp, sreg 102 103 #define RSTOR_XMM_EPILOG(sreg, nreg) \ 104 addq $_CONST(_MUL(XMM_SIZE, nreg)), %rsp 105 106 #elif defined(__i386) 107 108 #define SAVE_XMM_PROLOG(sreg, nreg) \ 109 subl $_CONST(_MUL(XMM_SIZE, nreg) + XMM_ALIGN), %esp; \ 110 movl %esp, sreg; \ 111 addl $XMM_ALIGN, sreg; \ 112 andl $_BITNOT(XMM_ALIGN-1), sreg 113 114 #define RSTOR_XMM_EPILOG(sreg, nreg) \ 115 addl $_CONST(_MUL(XMM_SIZE, nreg) + XMM_ALIGN), %esp; 116 117 #endif /* __i386 */ 118 119 /* 120 * profiling causes definitions of the MCOUNT and RTMCOUNT 121 * particular to the type 122 */ 123 #ifdef GPROF 124 125 #define MCOUNT(x) \ 126 pushl %ebp; \ 127 movl %esp, %ebp; \ 128 call _mcount; \ 129 popl %ebp 130 131 #endif /* GPROF */ 132 133 #ifdef PROF 134 135 #define MCOUNT(x) \ 136 /* CSTYLED */ \ 137 .lcomm .L_##x##1, 4, 4; \ 138 pushl %ebp; \ 139 movl %esp, %ebp; \ 140 /* CSTYLED */ \ 141 movl $.L_##x##1, %edx; \ 142 call _mcount; \ 143 popl %ebp 144 145 #endif /* PROF */ 146 147 /* 148 * if we are not profiling, MCOUNT should be defined to nothing 149 */ 150 #if !defined(PROF) && !defined(GPROF) 151 #define MCOUNT(x) 152 #endif /* !defined(PROF) && !defined(GPROF) */ 153 154 #define RTMCOUNT(x) MCOUNT(x) 155 156 /* 157 * Macro to define weak symbol aliases. These are similar to the ANSI-C 158 * #pragma weak _name = name 159 * except a compiler can determine type. The assembler must be told. Hence, 160 * the second parameter must be the type of the symbol (i.e.: function,...) 161 */ 162 #define ANSI_PRAGMA_WEAK(sym, stype) \ 163 /* CSTYLED */ \ 164 .weak _##sym; \ 165 /* CSTYLED */ \ 166 .type _##sym, @stype; \ 167 /* CSTYLED */ \ 168 _##sym = sym 169 170 /* 171 * Like ANSI_PRAGMA_WEAK(), but for unrelated names, as in: 172 * #pragma weak sym1 = sym2 173 */ 174 #define ANSI_PRAGMA_WEAK2(sym1, sym2, stype) \ 175 .weak sym1; \ 176 .type sym1, @stype; \ 177 sym1 = sym2 178 179 /* 180 * ENTRY provides the standard procedure entry code and an easy way to 181 * insert the calls to mcount for profiling. ENTRY_NP is identical, but 182 * never calls mcount. 183 */ 184 #define ENTRY(x) \ 185 .text; \ 186 .align ASM_ENTRY_ALIGN; \ 187 .globl x; \ 188 .type x, @function; \ 189 x: MCOUNT(x) 190 191 #define ENTRY_NP(x) \ 192 .text; \ 193 .align ASM_ENTRY_ALIGN; \ 194 .globl x; \ 195 .type x, @function; \ 196 x: 197 198 #define RTENTRY(x) \ 199 .text; \ 200 .align ASM_ENTRY_ALIGN; \ 201 .globl x; \ 202 .type x, @function; \ 203 x: RTMCOUNT(x) 204 205 /* 206 * ENTRY2 is identical to ENTRY but provides two labels for the entry point. 207 */ 208 #define ENTRY2(x, y) \ 209 .text; \ 210 .align ASM_ENTRY_ALIGN; \ 211 .globl x, y; \ 212 .type x, @function; \ 213 .type y, @function; \ 214 /* CSTYLED */ \ 215 x: ; \ 216 y: MCOUNT(x) 217 218 #define ENTRY_NP2(x, y) \ 219 .text; \ 220 .align ASM_ENTRY_ALIGN; \ 221 .globl x, y; \ 222 .type x, @function; \ 223 .type y, @function; \ 224 /* CSTYLED */ \ 225 x: ; \ 226 y: 227 228 229 /* 230 * ALTENTRY provides for additional entry points. 231 */ 232 #define ALTENTRY(x) \ 233 .globl x; \ 234 .type x, @function; \ 235 x: 236 237 /* 238 * DGDEF and DGDEF2 provide global data declarations. 239 * 240 * DGDEF provides a word aligned word of storage. 241 * 242 * DGDEF2 allocates "sz" bytes of storage with **NO** alignment. This 243 * implies this macro is best used for byte arrays. 244 * 245 * DGDEF3 allocates "sz" bytes of storage with "algn" alignment. 246 */ 247 #define DGDEF2(name, sz) \ 248 .data; \ 249 .globl name; \ 250 .type name, @object; \ 251 .size name, sz; \ 252 name: 253 254 #define DGDEF3(name, sz, algn) \ 255 .data; \ 256 .align algn; \ 257 .globl name; \ 258 .type name, @object; \ 259 .size name, sz; \ 260 name: 261 262 #define DGDEF(name) DGDEF3(name, 4, 4) 263 264 /* 265 * SET_SIZE trails a function and set the size for the ELF symbol table. 266 */ 267 #define SET_SIZE(x) \ 268 .size x, [.-x] 269 270 /* 271 * NWORD provides native word value. 272 */ 273 #if defined(__amd64) 274 275 /*CSTYLED*/ 276 #define NWORD quad 277 278 #elif defined(__i386) 279 280 #define NWORD long 281 282 #endif /* __i386 */ 283 284 /* 285 * These macros should be used when making indirect calls in the kernel. They 286 * will perform a jump or call to the corresponding register in a way that knows 287 * about retpolines and handles whether such mitigations are enabled or not. 288 * 289 * INDIRECT_JMP_REG will jump to named register. INDIRECT_CALL_REG will instead 290 * do a call. These macros cannot be used to dereference a register. For 291 * example, if you need to do something that looks like the following: 292 * 293 * call *24(%rdi) 294 * jmp *(%r15) 295 * 296 * You must instead first do a movq into the corresponding location. You need to 297 * be careful to make sure that the register that its loaded into is safe to 298 * use. Often that register may be saved or used elsewhere so it may not be safe 299 * to clobber the value. Usually, loading into %rax would be safe. These would 300 * turn into something like: 301 * 302 * movq 24(%rdi), %rdi; INDIRECT_CALL_REG(rdi) 303 * movq (%r15), %r15; INDIRECT_JMP_REG(r15) 304 * 305 * If you are trying to call a global function, then use the following pattern 306 * (substituting the register in question): 307 * 308 * leaq my_favorite_function(%rip), %rax 309 * INDIRECT_CALL_REG(rax) 310 * 311 * If you instead have a function pointer (say gethrtimef for example), then you 312 * need to do: 313 * 314 * movq my_favorite_function_pointer(%rip), %rax 315 * INDIRECT_CALL_REG(rax) 316 */ 317 318 /* CSTYLED */ 319 #define INDIRECT_JMP_REG(reg) jmp __x86_indirect_thunk_##reg; 320 321 /* CSTYLED */ 322 #define INDIRECT_CALL_REG(reg) call __x86_indirect_thunk_##reg; 323 324 #endif /* _ASM */ 325 326 #ifdef __cplusplus 327 } 328 #endif 329 330 #endif /* _SYS_ASM_LINKAGE_H */ 331