1 2/*--------------------------------------------------------------------*/ 3/*--- Doing syscalls. m_syscall.c ---*/ 4/*--------------------------------------------------------------------*/ 5 6/* 7 This file is part of Valgrind, a dynamic binary instrumentation 8 framework. 9 10 Copyright (C) 2000-2017 Julian Seward 11 jseward@acm.org 12 13 This program is free software; you can redistribute it and/or 14 modify it under the terms of the GNU General Public License as 15 published by the Free Software Foundation; either version 2 of the 16 License, or (at your option) any later version. 17 18 This program is distributed in the hope that it will be useful, but 19 WITHOUT ANY WARRANTY; without even the implied warranty of 20 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 21 General Public License for more details. 22 23 You should have received a copy of the GNU General Public License 24 along with this program; if not, write to the Free Software 25 Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 26 02111-1307, USA. 27 28 The GNU General Public License is contained in the file COPYING. 29*/ 30 31#include "pub_core_basics.h" 32#include "pub_core_libcassert.h" 33#include "pub_core_vki.h" 34#include "pub_core_vkiscnums.h" 35#include "pub_core_syscall.h" 36 37/* --------------------------------------------------------------------- 38 Building syscall return values. 39 ------------------------------------------------------------------ */ 40 41/* Make a SysRes value from a syscall return value. This is 42 platform specific. */ 43 44#if defined(VGP_mips32_linux) || defined(VGP_mips64_linux) 45 46SysRes VG_(mk_SysRes_mips32_linux) ( UWord v0, UWord v1, UWord a3 ) { 47 /* MIPS uses a3 != 0 to flag an error */ 48 SysRes res; 49 res._isError = (a3 != (UWord)0); 50 res._val = v0; 51 res._valEx = v1; 52 return res; 53} 54 55SysRes VG_(mk_SysRes_mips64_linux) ( ULong v0, ULong v1, ULong a3 ) { 56 /* MIPS uses a3 != 0 to flag an error */ 57 SysRes res; 58 res._isError = (a3 != (ULong)0); 59 res._val = v0; 60 res._valEx = v1; 61 return res; 62} 63 64/* Generic constructors. */ 65SysRes VG_(mk_SysRes_Error) ( UWord err ) { 66 SysRes r; 67 r._isError = True; 68 r._val = err; 69 r._valEx = 0; 70 return r; 71} 72 73SysRes VG_(mk_SysRes_Success) ( UWord res ) { 74 SysRes r; 75 r._isError = False; 76 r._val = res; 77 r._valEx = 0; 78 return r; 79} 80 81SysRes VG_(mk_SysRes_SuccessEx) ( UWord res, UWord resEx ) { 82 SysRes r; 83 r._isError = False; 84 r._val = res; 85 r._valEx = resEx; 86 return r; 87} 88 89 90#elif defined(VGO_linux) \ 91 && !defined(VGP_mips32_linux) && !defined(VGP_mips64_linux) 92 93/* 94 From: 95 http://sources.redhat.com/cgi-bin/cvsweb.cgi/libc/sysdeps/unix/sysv/ 96 linux/i386/sysdep.h? 97 rev=1.28&content-type=text/x-cvsweb-markup&cvsroot=glibc 98 99 Linux uses a negative return value to indicate syscall errors, 100 unlike most Unices, which use the condition codes' carry flag. 101 102 Since version 2.1 the return value of a system call might be 103 negative even if the call succeeded. E.g., the 'lseek' system call 104 might return a large offset. Therefore we must not anymore test 105 for < 0, but test for a real error by making sure the value in %eax 106 is a real error number. Linus said he will make sure the no 107 syscall returns a value in -1 .. -4095 as a valid result so we can 108 safely test with -4095. 109*/ 110 111SysRes VG_(mk_SysRes_x86_linux) ( Int val ) { 112 SysRes res; 113 res._isError = val >= -4095 && val <= -1; 114 if (res._isError) { 115 res._val = (UInt)(-val); 116 } else { 117 res._val = (UInt)val; 118 } 119 return res; 120} 121 122/* Similarly .. */ 123SysRes VG_(mk_SysRes_amd64_linux) ( Long val ) { 124 SysRes res; 125 res._isError = val >= -4095 && val <= -1; 126 if (res._isError) { 127 res._val = (ULong)(-val); 128 } else { 129 res._val = (ULong)val; 130 } 131 return res; 132} 133 134/* PPC uses the CR7.SO bit to flag an error (CR0 in IBM-speak) */ 135/* Note this must be in the bottom bit of the second arg */ 136SysRes VG_(mk_SysRes_ppc32_linux) ( UInt val, UInt cr0so ) { 137 SysRes res; 138 res._isError = (cr0so & 1) != 0; 139 res._val = val; 140 return res; 141} 142 143/* As per ppc32 version, cr0.so must be in l.s.b. of 2nd arg */ 144SysRes VG_(mk_SysRes_ppc64_linux) ( ULong val, ULong cr0so ) { 145 SysRes res; 146 res._isError = (cr0so & 1) != 0; 147 res._val = val; 148 return res; 149} 150 151SysRes VG_(mk_SysRes_s390x_linux) ( Long val ) { 152 SysRes res; 153 res._isError = val >= -4095 && val <= -1; 154 if (res._isError) { 155 res._val = -val; 156 } else { 157 res._val = val; 158 } 159 return res; 160} 161 162SysRes VG_(mk_SysRes_arm_linux) ( Int val ) { 163 SysRes res; 164 res._isError = val >= -4095 && val <= -1; 165 if (res._isError) { 166 res._val = (UInt)(-val); 167 } else { 168 res._val = (UInt)val; 169 } 170 return res; 171} 172 173SysRes VG_(mk_SysRes_arm64_linux) ( Long val ) { 174 SysRes res; 175 res._isError = val >= -4095 && val <= -1; 176 if (res._isError) { 177 res._val = (ULong)(-val); 178 } else { 179 res._val = (ULong)val; 180 } 181 return res; 182} 183 184/* Generic constructors. */ 185SysRes VG_(mk_SysRes_Error) ( UWord err ) { 186 SysRes r; 187 r._isError = True; 188 r._val = err; 189 return r; 190} 191 192SysRes VG_(mk_SysRes_Success) ( UWord res ) { 193 SysRes r; 194 r._isError = False; 195 r._val = res; 196 return r; 197} 198 199 200#elif defined(VGO_darwin) 201 202/* Darwin: Some syscalls return a double-word result. */ 203SysRes VG_(mk_SysRes_x86_darwin) ( UChar scclass, Bool isErr, 204 UInt wHI, UInt wLO ) 205{ 206 SysRes res; 207 res._wHI = 0; 208 res._wLO = 0; 209 res._mode = 0; /* invalid */ 210 vg_assert(isErr == False || isErr == True); 211 vg_assert(sizeof(UWord) == sizeof(UInt)); 212 switch (scclass) { 213 case VG_DARWIN_SYSCALL_CLASS_UNIX: 214 res._wLO = wLO; 215 res._wHI = wHI; 216 res._mode = isErr ? SysRes_UNIX_ERR : SysRes_UNIX_OK; 217 break; 218 case VG_DARWIN_SYSCALL_CLASS_MACH: 219 vg_assert(!isErr); 220 vg_assert(wHI == 0); 221 res._wLO = wLO; 222 res._mode = SysRes_MACH; 223 break; 224 case VG_DARWIN_SYSCALL_CLASS_MDEP: 225 vg_assert(!isErr); 226 vg_assert(wHI == 0); 227 res._wLO = wLO; 228 res._mode = SysRes_MDEP; 229 break; 230 default: 231 vg_assert(0); 232 } 233 return res; 234} 235 236SysRes VG_(mk_SysRes_amd64_darwin) ( UChar scclass, Bool isErr, 237 ULong wHI, ULong wLO ) 238{ 239 SysRes res; 240 res._wHI = 0; 241 res._wLO = 0; 242 res._mode = 0; /* invalid */ 243 vg_assert(isErr == False || isErr == True); 244 vg_assert(sizeof(UWord) == sizeof(ULong)); 245 switch (scclass) { 246 case VG_DARWIN_SYSCALL_CLASS_UNIX: 247 res._wLO = wLO; 248 res._wHI = wHI; 249 res._mode = isErr ? SysRes_UNIX_ERR : SysRes_UNIX_OK; 250 break; 251 case VG_DARWIN_SYSCALL_CLASS_MACH: 252 vg_assert(!isErr); 253 vg_assert(wHI == 0); 254 res._wLO = wLO; 255 res._mode = SysRes_MACH; 256 break; 257 case VG_DARWIN_SYSCALL_CLASS_MDEP: 258 vg_assert(!isErr); 259 vg_assert(wHI == 0); 260 res._wLO = wLO; 261 res._mode = SysRes_MDEP; 262 break; 263 default: 264 vg_assert(0); 265 } 266 return res; 267} 268 269/* Generic constructors. We assume (without checking if this makes 270 any sense, from the caller's point of view) that these are for the 271 UNIX style of syscall. */ 272SysRes VG_(mk_SysRes_Error) ( UWord err ) { 273 SysRes r; 274 r._wHI = 0; 275 r._wLO = err; 276 r._mode = SysRes_UNIX_ERR; 277 return r; 278} 279 280SysRes VG_(mk_SysRes_Success) ( UWord res ) { 281 SysRes r; 282 r._wHI = 0; 283 r._wLO = res; 284 r._mode = SysRes_UNIX_OK; 285 return r; 286} 287 288 289#elif defined(VGO_solaris) 290 291/* Generic constructors. */ 292SysRes VG_(mk_SysRes_Error) ( UWord err ) { 293 SysRes r; 294 r._val = err; 295 r._val2 = 0; 296 r._isError = True; 297 return r; 298} 299 300SysRes VG_(mk_SysRes_Success) ( UWord res ) { 301 SysRes r; 302 r._val = res; 303 r._val2 = 0; 304 r._isError = False; 305 return r; 306} 307 308SysRes VG_(mk_SysRes_x86_solaris) ( Bool isErr, UInt val, UInt val2 ) 309{ 310 SysRes res; 311 312 // stay sane 313 vg_assert(isErr == True || isErr == False); 314 315 res._val = val; 316 res._val2 = val2; 317 res._isError = isErr; 318 return res; 319} 320 321SysRes VG_(mk_SysRes_amd64_solaris) ( Bool isErr, ULong val, ULong val2 ) 322{ 323 SysRes res; 324 325 // stay sane 326 vg_assert(isErr == True || isErr == False); 327 328 res._val = val; 329 res._val2 = val2; 330 res._isError = isErr; 331 return res; 332} 333 334#else 335# error "Unknown OS" 336#endif 337 338 339/* --------------------------------------------------------------------- 340 VG_(do_syscall): A function for doing syscalls. 341 ------------------------------------------------------------------ */ 342 343#if defined(VGP_x86_linux) 344/* Incoming args (syscall number + up to 6 args) come on the stack. 345 (ie. the C calling convention). 346 347 The syscall number goes in %eax. The args are passed to the syscall in 348 the regs %ebx, %ecx, %edx, %esi, %edi, %ebp, ie. the kernel's syscall 349 calling convention. 350 351 %eax gets the return value. Not sure which registers the kernel 352 clobbers, so we preserve all the callee-save regs (%esi, %edi, %ebx, 353 %ebp). 354*/ 355extern UWord do_syscall_WRK ( 356 UWord syscall_no, 357 UWord a1, UWord a2, UWord a3, 358 UWord a4, UWord a5, UWord a6 359 ); 360asm( 361".text\n" 362".globl do_syscall_WRK\n" 363"do_syscall_WRK:\n" 364" .cfi_startproc\n" 365" push %esi\n" 366" .cfi_adjust_cfa_offset 4\n" 367" .cfi_offset %esi, -8\n" 368" push %edi\n" 369" .cfi_adjust_cfa_offset 4\n" 370" .cfi_offset %edi, -12\n" 371" push %ebx\n" 372" .cfi_adjust_cfa_offset 4\n" 373" .cfi_offset %ebx, -16\n" 374" push %ebp\n" 375" .cfi_adjust_cfa_offset 4\n" 376" .cfi_offset %ebp, -20\n" 377" movl 16+ 4(%esp),%eax\n" 378" movl 16+ 8(%esp),%ebx\n" 379" movl 16+12(%esp),%ecx\n" 380" movl 16+16(%esp),%edx\n" 381" movl 16+20(%esp),%esi\n" 382" movl 16+24(%esp),%edi\n" 383" movl 16+28(%esp),%ebp\n" 384" int $0x80\n" 385" popl %ebp\n" 386" .cfi_adjust_cfa_offset -4\n" 387" .cfi_restore %ebp\n" 388" popl %ebx\n" 389" .cfi_adjust_cfa_offset -4\n" 390" .cfi_restore %ebx\n" 391" popl %edi\n" 392" .cfi_adjust_cfa_offset -4\n" 393" .cfi_restore %edi\n" 394" popl %esi\n" 395" .cfi_adjust_cfa_offset -4\n" 396" .cfi_restore %esi\n" 397" ret\n" 398" .cfi_endproc\n" 399".previous\n" 400); 401 402#elif defined(VGP_amd64_linux) 403/* Incoming args (syscall number + up to 6 args) come in %rdi, %rsi, 404 %rdx, %rcx, %r8, %r9, and the last one on the stack (ie. the C 405 calling convention). 406 407 The syscall number goes in %rax. The args are passed to the syscall in 408 the regs %rdi, %rsi, %rdx, %r10, %r8, %r9 (yes, really %r10, not %rcx), 409 ie. the kernel's syscall calling convention. 410 411 %rax gets the return value. %rcx and %r11 are clobbered by the syscall; 412 no matter, they are caller-save (the syscall clobbers no callee-save 413 regs, so we don't have to do any register saving/restoring). 414*/ 415extern UWord do_syscall_WRK ( 416 UWord syscall_no, 417 UWord a1, UWord a2, UWord a3, 418 UWord a4, UWord a5, UWord a6 419 ); 420asm( 421".text\n" 422".globl do_syscall_WRK\n" 423"do_syscall_WRK:\n" 424 /* Convert function calling convention --> syscall calling 425 convention */ 426" movq %rdi, %rax\n" 427" movq %rsi, %rdi\n" 428" movq %rdx, %rsi\n" 429" movq %rcx, %rdx\n" 430" movq %r8, %r10\n" 431" movq %r9, %r8\n" 432" movq 8(%rsp), %r9\n" /* last arg from stack */ 433" syscall\n" 434" ret\n" 435".previous\n" 436); 437 438#elif defined(VGP_ppc32_linux) 439/* Incoming args (syscall number + up to 6 args) come in %r3:%r9. 440 441 The syscall number goes in %r0. The args are passed to the syscall in 442 the regs %r3:%r8, i.e. the kernel's syscall calling convention. 443 444 The %cr0.so bit flags an error. 445 We return the syscall return value in %r3, and the %cr0.so in 446 the lowest bit of %r4. 447 We return a ULong, of which %r3 is the high word, and %r4 the low. 448 No callee-save regs are clobbered, so no saving/restoring is needed. 449*/ 450extern ULong do_syscall_WRK ( 451 UWord syscall_no, 452 UWord a1, UWord a2, UWord a3, 453 UWord a4, UWord a5, UWord a6 454 ); 455asm( 456".text\n" 457".globl do_syscall_WRK\n" 458"do_syscall_WRK:\n" 459" mr 0,3\n" 460" mr 3,4\n" 461" mr 4,5\n" 462" mr 5,6\n" 463" mr 6,7\n" 464" mr 7,8\n" 465" mr 8,9\n" 466" sc\n" /* syscall: sets %cr0.so on error */ 467" mfcr 4\n" /* %cr -> low word of return var */ 468" rlwinm 4,4,4,31,31\n" /* rotate flag bit so to lsb, and mask it */ 469" blr\n" /* and return */ 470".previous\n" 471); 472 473#elif defined(VGP_ppc64be_linux) 474/* Due to the need to return 65 bits of result, this is completely 475 different from the ppc32 case. The single arg register points to a 476 7-word block containing the syscall # and the 6 args. The syscall 477 result proper is put in [0] of the block, and %cr0.so is in the 478 bottom bit of [1]. */ 479extern void do_syscall_WRK ( ULong* argblock ); 480asm( 481".align 2\n" 482".globl do_syscall_WRK\n" 483".section \".opd\",\"aw\"\n" 484".align 3\n" 485"do_syscall_WRK:\n" 486".quad .do_syscall_WRK,.TOC.@tocbase,0\n" 487".previous\n" 488".type .do_syscall_WRK,@function\n" 489".globl .do_syscall_WRK\n" 490".do_syscall_WRK:\n" 491" std 3,-16(1)\n" /* stash arg */ 492" ld 8, 48(3)\n" /* sc arg 6 */ 493" ld 7, 40(3)\n" /* sc arg 5 */ 494" ld 6, 32(3)\n" /* sc arg 4 */ 495" ld 5, 24(3)\n" /* sc arg 3 */ 496" ld 4, 16(3)\n" /* sc arg 2 */ 497" ld 0, 0(3)\n" /* sc number */ 498" ld 3, 8(3)\n" /* sc arg 1 */ 499" sc\n" /* result in r3 and cr0.so */ 500" ld 5,-16(1)\n" /* reacquire argblock ptr (r5 is caller-save) */ 501" std 3,0(5)\n" /* argblock[0] = r3 */ 502" mfcr 3\n" 503" srwi 3,3,28\n" 504" andi. 3,3,1\n" 505" std 3,8(5)\n" /* argblock[1] = cr0.s0 & 1 */ 506" blr\n" 507); 508 509#elif defined(VGP_ppc64le_linux) 510/* Due to the need to return 65 bits of result, this is completely 511 different from the ppc32 case. The single arg register points to a 512 7-word block containing the syscall # and the 6 args. The syscall 513 result proper is put in [0] of the block, and %cr0.so is in the 514 bottom bit of [1]. */ 515extern void do_syscall_WRK ( ULong* argblock ); 516/* Little Endian supports ELF version 2. In the future, it may support 517 * other versions as well. 518 */ 519asm( 520".align 2\n" 521".globl do_syscall_WRK\n" 522".type do_syscall_WRK,@function\n" 523"do_syscall_WRK:\n" 524"#if _CALL_ELF == 2" "\n" 525"0: addis 2,12,.TOC.-0b@ha\n" 526" addi 2,2,.TOC.-0b@l\n" 527" .localentry do_syscall_WRK, .-do_syscall_WRK\n" 528"#endif" "\n" 529" std 3,-16(1)\n" /* stash arg */ 530" ld 8, 48(3)\n" /* sc arg 6 */ 531" ld 7, 40(3)\n" /* sc arg 5 */ 532" ld 6, 32(3)\n" /* sc arg 4 */ 533" ld 5, 24(3)\n" /* sc arg 3 */ 534" ld 4, 16(3)\n" /* sc arg 2 */ 535" ld 0, 0(3)\n" /* sc number */ 536" ld 3, 8(3)\n" /* sc arg 1 */ 537" sc\n" /* result in r3 and cr0.so */ 538" ld 5,-16(1)\n" /* reacquire argblock ptr (r5 is caller-save) */ 539" std 3,0(5)\n" /* argblock[0] = r3 */ 540" mfcr 3\n" 541" srwi 3,3,28\n" 542" andi. 3,3,1\n" 543" std 3,8(5)\n" /* argblock[1] = cr0.s0 & 1 */ 544" blr\n" 545" .size do_syscall_WRK, .-do_syscall_WRK\n" 546); 547 548#elif defined(VGP_arm_linux) 549/* I think the conventions are: 550 args in r0 r1 r2 r3 r4 r5 551 sysno in r7 552 return value in r0, w/ same conventions as x86-linux, viz r0 in 553 -4096 .. -1 is an error value. All other values are success 554 values. 555*/ 556extern UWord do_syscall_WRK ( 557 UWord a1, UWord a2, UWord a3, 558 UWord a4, UWord a5, UWord a6, 559 UWord syscall_no 560 ); 561asm( 562".text\n" 563".globl do_syscall_WRK\n" 564"do_syscall_WRK:\n" 565" push {r4, r5, r7}\n" 566" ldr r4, [sp, #12]\n" 567" ldr r5, [sp, #16]\n" 568" ldr r7, [sp, #20]\n" 569" svc 0x0\n" 570" pop {r4, r5, r7}\n" 571" bx lr\n" 572".previous\n" 573); 574 575#elif defined(VGP_arm64_linux) 576/* I think the conventions are: 577 args in r0 r1 r2 r3 r4 r5 578 sysno in r8 579 return value in r0, w/ same conventions as x86-linux, viz r0 in 580 -4096 .. -1 is an error value. All other values are success 581 values. 582 583 r0 to r5 remain unchanged, but syscall_no is in r6 and needs 584 to be moved to r8 (??) 585*/ 586extern UWord do_syscall_WRK ( 587 UWord a1, UWord a2, UWord a3, 588 UWord a4, UWord a5, UWord a6, 589 UWord syscall_no 590 ); 591asm( 592".text\n" 593".globl do_syscall_WRK\n" 594"do_syscall_WRK:\n" 595" mov x8, x6\n" 596" mov x6, 0\n" 597" mov x7, 0\n" 598" svc 0\n" 599" ret\n" 600".previous\n" 601); 602 603#elif defined(VGP_x86_darwin) 604 605/* Incoming args (syscall number + up to 8 args) come in on the stack 606 607 The kernel's syscall calling convention is: 608 * the syscall number goes in eax 609 * the args are passed to the syscall on the stack, 610 pushed onto the stack R->L (that is, the usual x86 611 calling conventions, with the leftmost arg at the lowest 612 address) 613 Call instruction: 614 * UNIX: sysenter 615 * UNIX: int $0x80 616 * MACH: int $0x81 617 * MDEP: int $0x82 618 Note that the call type can be determined from the syscall number; 619 there is no need to inspect the actual instruction. Although obviously 620 the instruction must match. 621 Return value: 622 * MACH,MDEP: the return value comes back in eax 623 * UNIX: the return value comes back in edx:eax (hi32:lo32) 624 Error: 625 * MACH,MDEP: no error is returned 626 * UNIX: the carry flag indicates success or failure 627 628 nb here, sizeof(UWord) == sizeof(UInt) 629*/ 630 631__private_extern__ ULong 632do_syscall_unix_WRK ( UWord a1, UWord a2, UWord a3, /* 4(esp)..12(esp) */ 633 UWord a4, UWord a5, UWord a6, /* 16(esp)..24(esp) */ 634 UWord a7, UWord a8, /* 28(esp)..32(esp) */ 635 UWord syscall_no, /* 36(esp) */ 636 /*OUT*/UInt* errflag /* 40(esp) */ ); 637// Unix syscall: 64-bit return in edx:eax, with LSB in eax 638// error indicated by carry flag: clear=good, set=bad 639asm(".private_extern _do_syscall_unix_WRK\n" 640 "_do_syscall_unix_WRK:\n" 641 " movl 40(%esp), %ecx \n" /* assume syscall success */ 642 " movl $0, (%ecx) \n" 643 " movl 36(%esp), %eax \n" 644 " int $0x80 \n" 645 " jnc 1f \n" /* jump if success */ 646 " movl 40(%esp), %ecx \n" /* syscall failed - set *errflag */ 647 " movl $1, (%ecx) \n" 648 " 1: ret \n" 649 ); 650 651__private_extern__ UInt 652do_syscall_mach_WRK ( UWord a1, UWord a2, UWord a3, /* 4(esp)..12(esp) */ 653 UWord a4, UWord a5, UWord a6, /* 16(esp)..24(esp) */ 654 UWord a7, UWord a8, /* 28(esp)..32(esp) */ 655 UWord syscall_no /* 36(esp) */ ); 656// Mach trap: 32-bit result in %eax, no error flag 657asm(".private_extern _do_syscall_mach_WRK\n" 658 "_do_syscall_mach_WRK:\n" 659 " movl 36(%esp), %eax \n" 660 " int $0x81 \n" 661 " ret \n" 662 ); 663 664__private_extern__ UInt 665do_syscall_mdep_WRK ( UWord a1, UWord a2, UWord a3, /* 4(esp)..12(esp) */ 666 UWord a4, UWord a5, UWord a6, /* 16(esp)..24(esp) */ 667 UWord a7, UWord a8, /* 28(esp)..32(esp) */ 668 UWord syscall_no /* 36(esp) */ ); 669// mdep trap: 32-bit result in %eax, no error flag 670asm( 671 ".private_extern _do_syscall_mdep_WRK\n" 672 "_do_syscall_mdep_WRK:\n" 673 " movl 36(%esp), %eax \n" 674 " int $0x82 \n" 675 " ret \n" 676 ); 677 678 679#elif defined(VGP_amd64_darwin) 680 681/* Incoming args (syscall number + up to 8 args) come in registers and stack 682 683 The kernel's syscall calling convention is: 684 * the syscall number goes in rax 685 * the args are passed to the syscall in registers and the stack 686 * the call instruction is 'syscall' 687 Return value: 688 * MACH,MDEP: the return value comes back in rax 689 * UNIX: the return value comes back in rdx:rax (hi64:lo64) 690 Error: 691 * MACH,MDEP: no error is returned 692 * UNIX: the carry flag indicates success or failure 693 694 nb here, sizeof(UWord) == sizeof(ULong) 695*/ 696 697__private_extern__ UWord 698do_syscall_unix_WRK ( UWord a1, UWord a2, UWord a3, /* rdi, rsi, rdx */ 699 UWord a4, UWord a5, UWord a6, /* rcx, r8, r9 */ 700 UWord a7, UWord a8, /* 8(rsp), 16(rsp) */ 701 UWord syscall_no, /* 24(rsp) */ 702 /*OUT*/ULong* errflag, /* 32(rsp) */ 703 /*OUT*/ULong* res2 ); /* 40(rsp) */ 704// Unix syscall: 128-bit return in rax:rdx, with LSB in rax 705// error indicated by carry flag: clear=good, set=bad 706asm(".private_extern _do_syscall_unix_WRK\n" 707 "_do_syscall_unix_WRK:\n" 708 " movq %rcx, %r10 \n" /* pass rcx in r10 instead */ 709 " movq 32(%rsp), %rax \n" /* assume syscall success */ 710 " movq $0, (%rax) \n" 711 " movq 24(%rsp), %rax \n" /* load syscall_no */ 712 " syscall \n" 713 " jnc 1f \n" /* jump if success */ 714 " movq 32(%rsp), %rcx \n" /* syscall failed - set *errflag */ 715 " movq $1, (%rcx) \n" 716 " 1: movq 40(%rsp), %rcx \n" /* save 2nd result word */ 717 " movq %rdx, (%rcx) \n" 718 " retq \n" /* return 1st result word */ 719 ); 720 721__private_extern__ UWord 722do_syscall_mach_WRK ( UWord a1, UWord a2, UWord a3, /* rdi, rsi, rdx */ 723 UWord a4, UWord a5, UWord a6, /* rcx, r8, r9 */ 724 UWord a7, UWord a8, /* 8(rsp), 16(rsp) */ 725 UWord syscall_no ); /* 24(rsp) */ 726// Mach trap: 64-bit result, no error flag 727asm(".private_extern _do_syscall_mach_WRK\n" 728 "_do_syscall_mach_WRK:\n" 729 " movq %rcx, %r10 \n" /* pass rcx in r10 instead */ 730 " movq 24(%rsp), %rax \n" /* load syscall_no */ 731 " syscall \n" 732 " retq \n" 733 ); 734 735#elif defined(VGP_s390x_linux) 736 737static UWord do_syscall_WRK ( 738 UWord syscall_no, 739 UWord arg1, UWord arg2, UWord arg3, 740 UWord arg4, UWord arg5, UWord arg6 741 ) 742{ 743 register UWord __arg1 asm("2") = arg1; 744 register UWord __arg2 asm("3") = arg2; 745 register UWord __arg3 asm("4") = arg3; 746 register UWord __arg4 asm("5") = arg4; 747 register UWord __arg5 asm("6") = arg5; 748 register UWord __arg6 asm("7") = arg6; 749 register ULong __svcres asm("2"); 750 751 __asm__ __volatile__ ( 752 "lgr %%r1,%1\n\t" 753 "svc 0\n\t" 754 : "=d" (__svcres) 755 : "a" (syscall_no), 756 "0" (__arg1), 757 "d" (__arg2), 758 "d" (__arg3), 759 "d" (__arg4), 760 "d" (__arg5), 761 "d" (__arg6) 762 : "1", "cc", "memory"); 763 764 return (UWord) (__svcres); 765} 766 767#elif defined(VGP_mips32_linux) 768/* Incoming args (syscall number + up to 6 args) come in a0 - a3 and stack. 769 770 The syscall number goes in v0. The args are passed to the syscall in 771 the regs a0 - a3 and stack, i.e. the kernel's syscall calling convention. 772 773 (a3 != 0) flags an error. 774 We return the syscall return value in v0. 775 MIPS version 776*/ 777extern int do_syscall_WRK ( 778 int a1, int a2, int a3, 779 int a4, int a5, int a6, int syscall_no, UWord *err, 780 UWord *valHi, UWord* valLo 781 ); 782asm ( 783 ".text \n\t" 784 ".globl do_syscall_WRK \n\t" 785 ".type do_syscall_WRK, @function \n\t" 786 ".set push \n\t" 787 ".set noreorder \n\t" 788 "do_syscall_WRK: \n\t" 789 " lw $2, 24($29) \n\t" 790 " syscall \n\t" 791 " lw $8, 28($29) \n\t" 792 " sw $7, ($8) \n\t" 793 " lw $8, 32($29) \n\t" 794 " sw $3, ($8) \n\t" /* store valHi */ 795 " lw $8, 36($29) \n\t" 796 " jr $31 \n\t" 797 " sw $2, ($8) \n\t" /* store valLo */ 798 ".size do_syscall_WRK, .-do_syscall_WRK \n\t" 799 ".set pop \n\t" 800 ".previous \n\t" 801); 802 803#elif defined(VGP_mips64_linux) 804extern UWord do_syscall_WRK ( UWord a1, UWord a2, UWord a3, UWord a4, UWord a5, 805 UWord a6, UWord syscall_no, ULong* V1_A3_val ); 806asm ( 807 ".text \n\t" 808 ".globl do_syscall_WRK \n\t" 809 ".type do_syscall_WRK, @function \n\t" 810 ".set push \n\t" 811 ".set noreorder \n\t" 812 "do_syscall_WRK: \n\t" 813 " daddiu $29, $29, -8 \n\t" 814 " sd $11, 0($29) \n\t" 815 " move $2, $10 \n\t" 816 " syscall \n\t" 817 " ld $11, 0($29) \n\t" 818 " daddiu $29, $29, 8 \n\t" 819 " sd $3, 0($11) \n\t" /* store v1 in last param */ 820 " jr $31 \n\t" 821 " sd $7, 8($11) \n\t" /* store a3 in last param */ 822 ".size do_syscall_WRK, .-do_syscall_WRK \n\t" 823 ".set pop \n\t" 824 ".previous \n\t" 825); 826 827#elif defined(VGP_x86_solaris) 828 829extern ULong 830do_syscall_WRK(UWord a1, UWord a2, UWord a3, /* 4(esp)..12(esp) */ 831 UWord a4, UWord a5, UWord a6, /* 16(esp)..24(esp) */ 832 UWord a7, UWord a8, /* 28(esp)..32(esp) */ 833 UWord syscall_no, /* 36(esp) */ 834 /*OUT*/UInt *errflag); /* 40(esp) */ 835/* Classic unix syscall.. parameters on the stack, an unused (by the kernel) 836 return address at 0(esp), a sysno in eax, a result in edx:eax, the carry 837 flag set on error. */ 838__asm__ ( 839".text\n" 840".globl do_syscall_WRK\n" 841"do_syscall_WRK:\n" 842" movl 40(%esp), %ecx\n" /* assume syscall success */ 843" movl $0, (%ecx)\n" 844" movl 36(%esp), %eax\n" 845" int $0x91\n" 846" jnc 1f\n" /* jump if success */ 847" movl 40(%esp), %ecx\n" /* syscall failed - set *errflag */ 848" movl $1, (%ecx)\n" 849"1: ret\n" 850".previous\n" 851); 852 853extern ULong 854do_syscall_fast_WRK(UWord syscall_no); /* 4(esp) */ 855/* Fasttrap syscall.. no parameters, a sysno in eax, a result in edx:eax, 856 never fails (if the sysno is valid). */ 857__asm__ ( 858".text\n" 859".globl do_syscall_fast_WRK\n" 860"do_syscall_fast_WRK:\n" 861" movl 4(%esp), %eax\n" 862" int $0xD2\n" 863" ret\n" 864".previous\n" 865); 866 867#elif defined(VGP_amd64_solaris) 868 869extern ULong 870do_syscall_WRK(UWord a1, UWord a2, UWord a3, /* rdi, rsi, rdx */ 871 UWord a4, UWord a5, UWord a6, /* rcx, r8, r9 */ 872 UWord a7, UWord a8, /* 8(rsp), 16(rsp) */ 873 UWord syscall_no, /* 24(rsp) */ 874 /*OUT*/ULong *errflag, /* 32(rsp) */ 875 /*OUT*/ULong *res2); /* 40(rsp) */ 876/* First 6 parameters in registers rdi, rsi, rdx, r10, r8, r9, next 877 2 parameters on the stack, an unused (by the kernel) return address at 878 0(rsp), a sysno in rax, a result in rdx:rax, the carry flag set on 879 error. */ 880__asm__ ( 881".text\n" 882".globl do_syscall_WRK\n" 883"do_syscall_WRK:\n" 884" movq %rcx, %r10\n" /* pass rcx in r10 instead */ 885" movq 32(%rsp), %rcx\n" /* assume syscall success */ 886" movq $0, (%rcx)\n" 887" movq 24(%rsp), %rax\n" 888" syscall\n" 889" jnc 1f\n" /* jump if success */ 890" movq 32(%rsp), %rcx\n" /* syscall failed - set *errflag */ 891" movq $1, (%rcx)\n" 892"1: movq 40(%rsp), %rcx\n" /* save 2nd result word */ 893" movq %rdx, (%rcx)\n" 894" ret\n" 895".previous\n" 896); 897 898extern ULong 899do_syscall_fast_WRK(UWord syscall_no, /* rdi */ 900 /*OUT*/ULong *res2); /* rsi */ 901/* Fasttrap syscall.. no parameters, a sysno in rax, a result in rdx:rax, 902 never fails (if the sysno is valid). */ 903__asm__ ( 904".text\n" 905".globl do_syscall_fast_WRK\n" 906"do_syscall_fast_WRK:\n" 907" movq %rdi, %rax\n" 908" int $0xD2\n" 909" movq %rdx, (%rsi)\n" /* save 2nd result word */ 910" ret\n" 911".previous\n" 912); 913 914#else 915# error Unknown platform 916#endif 917 918 919/* Finally, the generic code. This sends the call to the right 920 helper. */ 921 922SysRes VG_(do_syscall) ( UWord sysno, UWord a1, UWord a2, UWord a3, 923 UWord a4, UWord a5, UWord a6, 924 UWord a7, UWord a8 ) 925{ 926# if defined(VGP_x86_linux) 927 UWord val = do_syscall_WRK(sysno,a1,a2,a3,a4,a5,a6); 928 return VG_(mk_SysRes_x86_linux)( val ); 929 930# elif defined(VGP_amd64_linux) 931 UWord val = do_syscall_WRK(sysno,a1,a2,a3,a4,a5,a6); 932 return VG_(mk_SysRes_amd64_linux)( val ); 933 934# elif defined(VGP_ppc32_linux) 935 ULong ret = do_syscall_WRK(sysno,a1,a2,a3,a4,a5,a6); 936 UInt val = (UInt)(ret>>32); 937 UInt cr0so = (UInt)(ret); 938 return VG_(mk_SysRes_ppc32_linux)( val, cr0so ); 939 940# elif defined(VGP_ppc64be_linux) || defined(VGP_ppc64le_linux) 941 ULong argblock[7]; 942 argblock[0] = sysno; 943 argblock[1] = a1; 944 argblock[2] = a2; 945 argblock[3] = a3; 946 argblock[4] = a4; 947 argblock[5] = a5; 948 argblock[6] = a6; 949 do_syscall_WRK( &argblock[0] ); 950 return VG_(mk_SysRes_ppc64_linux)( argblock[0], argblock[1] ); 951 952# elif defined(VGP_arm_linux) 953 UWord val = do_syscall_WRK(a1,a2,a3,a4,a5,a6,sysno); 954 return VG_(mk_SysRes_arm_linux)( val ); 955 956# elif defined(VGP_arm64_linux) 957 UWord val = do_syscall_WRK(a1,a2,a3,a4,a5,a6,sysno); 958 return VG_(mk_SysRes_arm64_linux)( val ); 959 960# elif defined(VGP_x86_darwin) 961 UInt wLO = 0, wHI = 0, err = 0; 962 ULong u64; 963 UChar scclass = VG_DARWIN_SYSNO_CLASS(sysno); 964 switch (scclass) { 965 case VG_DARWIN_SYSCALL_CLASS_UNIX: 966 u64 = do_syscall_unix_WRK(a1,a2,a3,a4,a5,a6,a7,a8, 967 VG_DARWIN_SYSNO_FOR_KERNEL(sysno), &err); 968 wLO = (UInt)u64; 969 wHI = (UInt)(u64 >> 32); 970 break; 971 case VG_DARWIN_SYSCALL_CLASS_MACH: 972 wLO = do_syscall_mach_WRK(a1,a2,a3,a4,a5,a6,a7,a8, 973 VG_DARWIN_SYSNO_FOR_KERNEL(sysno)); 974 err = 0; 975 break; 976 case VG_DARWIN_SYSCALL_CLASS_MDEP: 977 wLO = do_syscall_mdep_WRK(a1,a2,a3,a4,a5,a6,a7,a8, 978 VG_DARWIN_SYSNO_FOR_KERNEL(sysno)); 979 err = 0; 980 break; 981 default: 982 vg_assert(0); 983 break; 984 } 985 return VG_(mk_SysRes_x86_darwin)( scclass, err ? True : False, wHI, wLO ); 986 987# elif defined(VGP_amd64_darwin) 988 ULong wLO = 0, wHI = 0, err = 0; 989 UChar scclass = VG_DARWIN_SYSNO_CLASS(sysno); 990 switch (scclass) { 991 case VG_DARWIN_SYSCALL_CLASS_UNIX: 992 wLO = do_syscall_unix_WRK(a1,a2,a3,a4,a5,a6,a7,a8, 993 VG_DARWIN_SYSNO_FOR_KERNEL(sysno), &err, &wHI); 994 break; 995 case VG_DARWIN_SYSCALL_CLASS_MACH: 996 case VG_DARWIN_SYSCALL_CLASS_MDEP: 997 wLO = do_syscall_mach_WRK(a1,a2,a3,a4,a5,a6,a7,a8, 998 VG_DARWIN_SYSNO_FOR_KERNEL(sysno)); 999 err = 0; 1000 break; 1001 default: 1002 vg_assert(0); 1003 break; 1004 } 1005 return VG_(mk_SysRes_amd64_darwin)( scclass, err ? True : False, wHI, wLO ); 1006 1007#elif defined(VGP_s390x_linux) 1008 UWord val; 1009 1010 if (sysno == __NR_mmap) { 1011 ULong argbuf[6]; 1012 1013 argbuf[0] = a1; 1014 argbuf[1] = a2; 1015 argbuf[2] = a3; 1016 argbuf[3] = a4; 1017 argbuf[4] = a5; 1018 argbuf[5] = a6; 1019 val = do_syscall_WRK(sysno,(UWord)&argbuf[0],0,0,0,0,0); 1020 } else { 1021 val = do_syscall_WRK(sysno,a1,a2,a3,a4,a5,a6); 1022 } 1023 1024 return VG_(mk_SysRes_s390x_linux)( val ); 1025 1026#elif defined(VGP_mips32_linux) 1027 UWord err = 0; 1028 UWord valHi = 0; 1029 UWord valLo = 0; 1030 (void) do_syscall_WRK(a1,a2,a3,a4,a5,a6, sysno,&err,&valHi,&valLo); 1031 return VG_(mk_SysRes_mips32_linux)( valLo, valHi, (ULong)err ); 1032 1033#elif defined(VGP_mips64_linux) 1034 ULong v1_a3[2]; 1035 v1_a3[0] = 0xFF00; 1036 v1_a3[1] = 0xFF00; 1037 ULong V0 = do_syscall_WRK(a1,a2,a3,a4,a5,a6,sysno,v1_a3); 1038 ULong V1 = (ULong)v1_a3[0]; 1039 ULong A3 = (ULong)v1_a3[1]; 1040 return VG_(mk_SysRes_mips64_linux)( V0, V1, A3 ); 1041 1042# elif defined(VGP_x86_solaris) 1043 UInt val, val2, err = False; 1044 Bool restart; 1045 ULong u64; 1046 UChar ssclass = VG_SOLARIS_SYSNO_CLASS(sysno); 1047 1048 switch (ssclass) { 1049 case VG_SOLARIS_SYSCALL_CLASS_CLASSIC: 1050 /* The Solaris kernel does not restart syscalls automatically so it 1051 is done here. */ 1052 do { 1053 u64 = do_syscall_WRK(a1,a2,a3,a4,a5,a6,a7,a8, 1054 VG_SOLARIS_SYSNO_INDEX(sysno), &err); 1055 val = (UInt)u64; 1056 restart = err && (val == VKI_EINTR || val == VKI_ERESTART); 1057 } while (restart); 1058 break; 1059 case VG_SOLARIS_SYSCALL_CLASS_FASTTRAP: 1060 u64 = do_syscall_fast_WRK(VG_SOLARIS_SYSNO_INDEX(sysno)); 1061 break; 1062 default: 1063 vg_assert(0); 1064 break; 1065 } 1066 1067 val = (UInt)u64; 1068 val2 = (UInt)(u64 >> 32); 1069 return VG_(mk_SysRes_x86_solaris)(err ? True : False, val, 1070 err ? 0 : val2); 1071 1072# elif defined(VGP_amd64_solaris) 1073 ULong val, val2, err = False; 1074 Bool restart; 1075 UChar ssclass = VG_SOLARIS_SYSNO_CLASS(sysno); 1076 1077 switch (ssclass) { 1078 case VG_SOLARIS_SYSCALL_CLASS_CLASSIC: 1079 /* The Solaris kernel does not restart syscalls automatically so it 1080 is done here. */ 1081 do { 1082 val = do_syscall_WRK(a1,a2,a3,a4,a5,a6,a7,a8, 1083 VG_SOLARIS_SYSNO_INDEX(sysno), &err, &val2); 1084 restart = err && (val == VKI_EINTR || val == VKI_ERESTART); 1085 } while (restart); 1086 break; 1087 case VG_SOLARIS_SYSCALL_CLASS_FASTTRAP: 1088 val = do_syscall_fast_WRK(VG_SOLARIS_SYSNO_INDEX(sysno), &val2); 1089 break; 1090 default: 1091 vg_assert(0); 1092 break; 1093 } 1094 1095 return VG_(mk_SysRes_amd64_solaris)(err ? True : False, val, 1096 err ? 0 : val2); 1097 1098#else 1099# error Unknown platform 1100#endif 1101} 1102 1103/* --------------------------------------------------------------------- 1104 Names of errors. 1105 ------------------------------------------------------------------ */ 1106 1107/* Return a string which gives the name of an error value. Note, 1108 unlike the standard C syserror fn, the returned string is not 1109 malloc-allocated or writable -- treat it as a constant. 1110 TODO: implement this properly. */ 1111 1112const HChar* VG_(strerror) ( UWord errnum ) 1113{ 1114 switch (errnum) { 1115 case VKI_EPERM: return "Operation not permitted"; 1116 case VKI_ENOENT: return "No such file or directory"; 1117 case VKI_ESRCH: return "No such process"; 1118 case VKI_EINTR: return "Interrupted system call"; 1119 case VKI_EIO: return "Input/output error"; 1120 case VKI_ENXIO: return "No such device or address"; 1121 case VKI_E2BIG: return "Argument list too long"; 1122 case VKI_ENOEXEC: return "Exec format error"; 1123 case VKI_EBADF: return "Bad file descriptor"; 1124 case VKI_ECHILD: return "No child processes"; 1125 case VKI_EAGAIN: return "Resource temporarily unavailable"; 1126 case VKI_ENOMEM: return "Cannot allocate memory"; 1127 case VKI_EACCES: return "Permission denied"; 1128 case VKI_EFAULT: return "Bad address"; 1129 case VKI_ENOTBLK: return "Block device required"; 1130 case VKI_EBUSY: return "Device or resource busy"; 1131 case VKI_EEXIST: return "File exists"; 1132 case VKI_EXDEV: return "Invalid cross-device link"; 1133 case VKI_ENODEV: return "No such device"; 1134 case VKI_ENOTDIR: return "Not a directory"; 1135 case VKI_EISDIR: return "Is a directory"; 1136 case VKI_EINVAL: return "Invalid argument"; 1137 case VKI_ENFILE: return "Too many open files in system"; 1138 case VKI_EMFILE: return "Too many open files"; 1139 case VKI_ENOTTY: return "Inappropriate ioctl for device"; 1140 case VKI_ETXTBSY: return "Text file busy"; 1141 case VKI_EFBIG: return "File too large"; 1142 case VKI_ENOSPC: return "No space left on device"; 1143 case VKI_ESPIPE: return "Illegal seek"; 1144 case VKI_EROFS: return "Read-only file system"; 1145 case VKI_EMLINK: return "Too many links"; 1146 case VKI_EPIPE: return "Broken pipe"; 1147 case VKI_EDOM: return "Numerical argument out of domain"; 1148 case VKI_ERANGE: return "Numerical result out of range"; 1149 1150 case VKI_ENOSYS: return "Function not implemented"; 1151 case VKI_EOVERFLOW: return "Value too large for defined data type"; 1152# if defined(VKI_ERESTARTSYS) 1153 case VKI_ERESTARTSYS: return "ERESTARTSYS"; 1154# endif 1155 default: return "VG_(strerror): unknown error"; 1156 } 1157} 1158 1159 1160/*--------------------------------------------------------------------*/ 1161/*--- end ---*/ 1162/*--------------------------------------------------------------------*/ 1163