github.com/spotify/syslog-redirector-golang@v0.0.0-20140320174030-4859f03d829a/src/pkg/runtime/sys_freebsd_amd64.s (about) 1 // Copyright 2009 The Go Authors. All rights reserved. 2 // Use of this source code is governed by a BSD-style 3 // license that can be found in the LICENSE file. 4 // 5 // System calls and other sys.stuff for AMD64, FreeBSD 6 // /usr/src/sys/kern/syscalls.master for syscall numbers. 7 // 8 9 #include "zasm_GOOS_GOARCH.h" 10 #include "../../cmd/ld/textflag.h" 11 12 // FreeBSD 8, FreeBSD 9, and older versions that I have checked 13 // do not restore R10 on exit from a "restarted" system call 14 // if you use the SYSCALL instruction. This means that, for example, 15 // if a signal arrives while the wait4 system call is executing, 16 // the wait4 internally returns ERESTART, which makes the kernel 17 // back up the PC to execute the SYSCALL instruction a second time. 18 // However, since the kernel does not restore R10, the fourth 19 // argument to the system call has been lost. (FreeBSD 9 also fails 20 // to restore the fifth and sixth arguments, R8 and R9, although 21 // some earlier versions did restore those correctly.) 22 // The broken code is in fast_syscall in FreeBSD's amd64/amd64/exception.S. 23 // It restores only DI, SI, DX, AX, and RFLAGS on system call return. 24 // http://fxr.watson.org/fxr/source/amd64/amd64/exception.S?v=FREEBSD91#L399 25 // 26 // The INT $0x80 system call path (int0x80_syscall in FreeBSD's 27 // amd64/ia32/ia32_exception.S) does not have this problem, 28 // but it expects the third argument in R10. Instead of rewriting 29 // all the assembly in this file, #define SYSCALL to a safe simulation 30 // using INT $0x80. 31 // 32 // INT $0x80 is a little slower than SYSCALL, but correctness wins. 33 // 34 // See golang.org/issue/6372. 35 #define SYSCALL MOVQ R10, CX; INT $0x80 36 37 TEXT runtime·sys_umtx_op(SB),NOSPLIT,$0 38 MOVQ 8(SP), DI 39 MOVL 16(SP), SI 40 MOVL 20(SP), DX 41 MOVQ 24(SP), R10 42 MOVQ 32(SP), R8 43 MOVL $454, AX 44 SYSCALL 45 RET 46 47 TEXT runtime·thr_new(SB),NOSPLIT,$0 48 MOVQ 8(SP), DI 49 MOVQ 16(SP), SI 50 MOVL $455, AX 51 SYSCALL 52 RET 53 54 TEXT runtime·thr_start(SB),NOSPLIT,$0 55 MOVQ DI, R13 // m 56 57 // set up FS to point at m->tls 58 LEAQ m_tls(R13), DI 59 CALL runtime·settls(SB) // smashes DI 60 61 // set up m, g 62 get_tls(CX) 63 MOVQ R13, m(CX) 64 MOVQ m_g0(R13), DI 65 MOVQ DI, g(CX) 66 67 CALL runtime·stackcheck(SB) 68 CALL runtime·mstart(SB) 69 70 MOVQ 0, AX // crash (not reached) 71 72 // Exit the entire program (like C exit) 73 TEXT runtime·exit(SB),NOSPLIT,$-8 74 MOVL 8(SP), DI // arg 1 exit status 75 MOVL $1, AX 76 SYSCALL 77 MOVL $0xf1, 0xf1 // crash 78 RET 79 80 TEXT runtime·exit1(SB),NOSPLIT,$-8 81 MOVQ 8(SP), DI // arg 1 exit status 82 MOVL $431, AX 83 SYSCALL 84 MOVL $0xf1, 0xf1 // crash 85 RET 86 87 TEXT runtime·open(SB),NOSPLIT,$-8 88 MOVQ 8(SP), DI // arg 1 pathname 89 MOVL 16(SP), SI // arg 2 flags 90 MOVL 20(SP), DX // arg 3 mode 91 MOVL $5, AX 92 SYSCALL 93 RET 94 95 TEXT runtime·close(SB),NOSPLIT,$-8 96 MOVL 8(SP), DI // arg 1 fd 97 MOVL $6, AX 98 SYSCALL 99 RET 100 101 TEXT runtime·read(SB),NOSPLIT,$-8 102 MOVL 8(SP), DI // arg 1 fd 103 MOVQ 16(SP), SI // arg 2 buf 104 MOVL 24(SP), DX // arg 3 count 105 MOVL $3, AX 106 SYSCALL 107 RET 108 109 TEXT runtime·write(SB),NOSPLIT,$-8 110 MOVL 8(SP), DI // arg 1 fd 111 MOVQ 16(SP), SI // arg 2 buf 112 MOVL 24(SP), DX // arg 3 count 113 MOVL $4, AX 114 SYSCALL 115 RET 116 117 TEXT runtime·getrlimit(SB),NOSPLIT,$-8 118 MOVL 8(SP), DI 119 MOVQ 16(SP), SI 120 MOVL $194, AX 121 SYSCALL 122 RET 123 124 TEXT runtime·raise(SB),NOSPLIT,$16 125 // thr_self(&8(SP)) 126 LEAQ 8(SP), DI // arg 1 &8(SP) 127 MOVL $432, AX 128 SYSCALL 129 // thr_kill(self, SIGPIPE) 130 MOVQ 8(SP), DI // arg 1 id 131 MOVL sig+0(FP), SI // arg 2 132 MOVL $433, AX 133 SYSCALL 134 RET 135 136 TEXT runtime·setitimer(SB), NOSPLIT, $-8 137 MOVL 8(SP), DI 138 MOVQ 16(SP), SI 139 MOVQ 24(SP), DX 140 MOVL $83, AX 141 SYSCALL 142 RET 143 144 // func now() (sec int64, nsec int32) 145 TEXT time·now(SB), NOSPLIT, $32 146 MOVL $232, AX 147 MOVQ $0, DI 148 LEAQ 8(SP), SI 149 SYSCALL 150 MOVQ 8(SP), AX // sec 151 MOVQ 16(SP), DX // nsec 152 153 // sec is in AX, nsec in DX 154 MOVQ AX, sec+0(FP) 155 MOVL DX, nsec+8(FP) 156 RET 157 158 TEXT runtime·nanotime(SB), NOSPLIT, $32 159 MOVL $232, AX 160 MOVQ $0, DI 161 LEAQ 8(SP), SI 162 SYSCALL 163 MOVQ 8(SP), AX // sec 164 MOVQ 16(SP), DX // nsec 165 166 // sec is in AX, nsec in DX 167 // return nsec in AX 168 IMULQ $1000000000, AX 169 ADDQ DX, AX 170 RET 171 172 TEXT runtime·sigaction(SB),NOSPLIT,$-8 173 MOVL 8(SP), DI // arg 1 sig 174 MOVQ 16(SP), SI // arg 2 act 175 MOVQ 24(SP), DX // arg 3 oact 176 MOVL $416, AX 177 SYSCALL 178 JCC 2(PC) 179 MOVL $0xf1, 0xf1 // crash 180 RET 181 182 TEXT runtime·sigtramp(SB),NOSPLIT,$64 183 get_tls(BX) 184 185 // check that m exists 186 MOVQ m(BX), BP 187 CMPQ BP, $0 188 JNE 5(PC) 189 MOVQ DI, 0(SP) 190 MOVQ $runtime·badsignal(SB), AX 191 CALL AX 192 RET 193 194 // save g 195 MOVQ g(BX), R10 196 MOVQ R10, 40(SP) 197 198 // g = m->signal 199 MOVQ m_gsignal(BP), BP 200 MOVQ BP, g(BX) 201 202 MOVQ DI, 0(SP) 203 MOVQ SI, 8(SP) 204 MOVQ DX, 16(SP) 205 MOVQ R10, 24(SP) 206 207 CALL runtime·sighandler(SB) 208 209 // restore g 210 get_tls(BX) 211 MOVQ 40(SP), R10 212 MOVQ R10, g(BX) 213 RET 214 215 TEXT runtime·mmap(SB),NOSPLIT,$0 216 MOVQ 8(SP), DI // arg 1 addr 217 MOVQ 16(SP), SI // arg 2 len 218 MOVL 24(SP), DX // arg 3 prot 219 MOVL 28(SP), R10 // arg 4 flags 220 MOVL 32(SP), R8 // arg 5 fid 221 MOVL 36(SP), R9 // arg 6 offset 222 MOVL $477, AX 223 SYSCALL 224 RET 225 226 TEXT runtime·munmap(SB),NOSPLIT,$0 227 MOVQ 8(SP), DI // arg 1 addr 228 MOVQ 16(SP), SI // arg 2 len 229 MOVL $73, AX 230 SYSCALL 231 JCC 2(PC) 232 MOVL $0xf1, 0xf1 // crash 233 RET 234 235 TEXT runtime·madvise(SB),NOSPLIT,$0 236 MOVQ 8(SP), DI 237 MOVQ 16(SP), SI 238 MOVQ 24(SP), DX 239 MOVQ $75, AX // madvise 240 SYSCALL 241 // ignore failure - maybe pages are locked 242 RET 243 244 TEXT runtime·sigaltstack(SB),NOSPLIT,$-8 245 MOVQ new+8(SP), DI 246 MOVQ old+16(SP), SI 247 MOVQ $53, AX 248 SYSCALL 249 JCC 2(PC) 250 MOVL $0xf1, 0xf1 // crash 251 RET 252 253 TEXT runtime·usleep(SB),NOSPLIT,$16 254 MOVL $0, DX 255 MOVL usec+0(FP), AX 256 MOVL $1000000, CX 257 DIVL CX 258 MOVQ AX, 0(SP) // tv_sec 259 MOVL $1000, AX 260 MULL DX 261 MOVQ AX, 8(SP) // tv_nsec 262 263 MOVQ SP, DI // arg 1 - rqtp 264 MOVQ $0, SI // arg 2 - rmtp 265 MOVL $240, AX // sys_nanosleep 266 SYSCALL 267 RET 268 269 // set tls base to DI 270 TEXT runtime·settls(SB),NOSPLIT,$8 271 ADDQ $16, DI // adjust for ELF: wants to use -16(FS) and -8(FS) for g and m 272 MOVQ DI, 0(SP) 273 MOVQ SP, SI 274 MOVQ $129, DI // AMD64_SET_FSBASE 275 MOVQ $165, AX // sysarch 276 SYSCALL 277 JCC 2(PC) 278 MOVL $0xf1, 0xf1 // crash 279 RET 280 281 TEXT runtime·sysctl(SB),NOSPLIT,$0 282 MOVQ 8(SP), DI // arg 1 - name 283 MOVL 16(SP), SI // arg 2 - namelen 284 MOVQ 24(SP), DX // arg 3 - oldp 285 MOVQ 32(SP), R10 // arg 4 - oldlenp 286 MOVQ 40(SP), R8 // arg 5 - newp 287 MOVQ 48(SP), R9 // arg 6 - newlen 288 MOVQ $202, AX // sys___sysctl 289 SYSCALL 290 JCC 3(PC) 291 NEGQ AX 292 RET 293 MOVL $0, AX 294 RET 295 296 TEXT runtime·osyield(SB),NOSPLIT,$-4 297 MOVL $331, AX // sys_sched_yield 298 SYSCALL 299 RET 300 301 TEXT runtime·sigprocmask(SB),NOSPLIT,$0 302 MOVL $3, DI // arg 1 - how (SIG_SETMASK) 303 MOVQ 8(SP), SI // arg 2 - set 304 MOVQ 16(SP), DX // arg 3 - oset 305 MOVL $340, AX // sys_sigprocmask 306 SYSCALL 307 JAE 2(PC) 308 MOVL $0xf1, 0xf1 // crash 309 RET 310 311 // int32 runtime·kqueue(void); 312 TEXT runtime·kqueue(SB),NOSPLIT,$0 313 MOVQ $0, DI 314 MOVQ $0, SI 315 MOVQ $0, DX 316 MOVL $362, AX 317 SYSCALL 318 JCC 2(PC) 319 NEGQ AX 320 RET 321 322 // int32 runtime·kevent(int kq, Kevent *changelist, int nchanges, Kevent *eventlist, int nevents, Timespec *timeout); 323 TEXT runtime·kevent(SB),NOSPLIT,$0 324 MOVL 8(SP), DI 325 MOVQ 16(SP), SI 326 MOVL 24(SP), DX 327 MOVQ 32(SP), R10 328 MOVL 40(SP), R8 329 MOVQ 48(SP), R9 330 MOVL $363, AX 331 SYSCALL 332 JCC 2(PC) 333 NEGQ AX 334 RET 335 336 // void runtime·closeonexec(int32 fd); 337 TEXT runtime·closeonexec(SB),NOSPLIT,$0 338 MOVL 8(SP), DI // fd 339 MOVQ $2, SI // F_SETFD 340 MOVQ $1, DX // FD_CLOEXEC 341 MOVL $92, AX // fcntl 342 SYSCALL 343 RET