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      1 
      2 /*--------------------------------------------------------------------*/
      3 /*--- Header included by every tool C file.      pub_tool_basics.h ---*/
      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 (at) 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 #ifndef __PUB_TOOL_BASICS_H
     32 #define __PUB_TOOL_BASICS_H
     33 
     34 //--------------------------------------------------------------------
     35 // PURPOSE: This header should be imported by every single C file in
     36 // tools.  It contains the basic types and other things needed everywhere.
     37 // There is no corresponding C file because this isn't a module
     38 // containing executable code, it's all just declarations.
     39 //--------------------------------------------------------------------
     40 
     41 /* ---------------------------------------------------------------------
     42    Other headers to include
     43    ------------------------------------------------------------------ */
     44 
     45 // VEX defines Char, UChar, Short, UShort, Int, UInt, Long, ULong, SizeT,
     46 // Addr, Addr32, Addr64, HWord, HChar, Bool, False and True.
     47 #include "libvex_basictypes.h"
     48 
     49 // For varargs types
     50 #include <stdarg.h>
     51 
     52 
     53 /* ---------------------------------------------------------------------
     54    symbol prefixing
     55    ------------------------------------------------------------------ */
     56 
     57 // All symbols externally visible from Valgrind are prefixed
     58 // as specified here to avoid namespace conflict problems.
     59 //
     60 // VG_ is for symbols exported from modules.  ML_ (module-local) is
     61 // for symbols which are not intended to be visible outside modules,
     62 // but which cannot be declared as C 'static's since they need to be
     63 // visible across C files within a given module.  It is a mistake for
     64 // a ML_ name to appear in a pub_core_*.h or pub_tool_*.h file.
     65 // Likewise it is a mistake for a VG_ name to appear in a priv_*.h
     66 // file.
     67 
     68 #define VGAPPEND(str1,str2) str1##str2
     69 
     70 #define VG_(str)    VGAPPEND(vgPlain_,          str)
     71 #define ML_(str)    VGAPPEND(vgModuleLocal_,    str)
     72 
     73 
     74 /* ---------------------------------------------------------------------
     75    builtin types
     76    ------------------------------------------------------------------ */
     77 
     78 // By choosing the right types, we can get these right for 32-bit and 64-bit
     79 // platforms without having to do any conditional compilation or anything.
     80 // POSIX references:
     81 // - http://www.opengroup.org/onlinepubs/009695399/basedefs/sys/types.h.html
     82 // - http://www.opengroup.org/onlinepubs/009695399/basedefs/stddef.h.html
     83 //
     84 // Size in bits on:                          32-bit archs   64-bit archs
     85 //                                           ------------   ------------
     86 typedef unsigned long          UWord;     // 32             64
     87 typedef   signed long           Word;     // 32             64
     88 
     89 // Our equivalent of POSIX 'ssize_t':
     90 // - ssize_t is "used for a count of bytes or an error indication".
     91 typedef  Word                 SSizeT;     // 32             64
     92 
     93 // Our equivalent of POSIX 'ptrdiff_t':
     94 // - ptrdiff_t is a "signed integer type of the result of subtracting two
     95 //   pointers".
     96 // We use it for memory offsets, eg. the offset into a memory block.
     97 typedef  Word                 PtrdiffT;   // 32             64
     98 
     99 // Our equivalent of POSIX 'off_t':
    100 // - off_t is "used for file sizes".
    101 // At one point we were using it for memory offsets, but PtrdiffT should be
    102 // used in those cases.
    103 // Nb: on Linux, off_t is a signed word-sized int.  On Darwin it's
    104 // always a signed 64-bit int.  So we defined our own Off64T as well.
    105 #if defined(VGO_linux) || defined(VGO_solaris)
    106 typedef Word                   OffT;      // 32             64
    107 #elif defined(VGO_darwin)
    108 typedef Long                   OffT;      // 64             64
    109 #else
    110 #  error Unknown OS
    111 #endif
    112 typedef Long                 Off64T;      // 64             64
    113 
    114 #if !defined(NULL)
    115 #  define NULL ((void*)0)
    116 #endif
    117 
    118 /* This is just too useful to not have around the place somewhere. */
    119 typedef  struct { UWord uw1; UWord uw2; }  UWordPair;
    120 
    121 
    122 /* ---------------------------------------------------------------------
    123    non-builtin types
    124    ------------------------------------------------------------------ */
    125 
    126 // These probably shouldn't be here, but moving them to their logical
    127 // modules results in a lot more #includes...
    128 
    129 /* ThreadIds are simply indices into the VG_(threads)[] array. */
    130 typedef UInt ThreadId;
    131 
    132 /* Many data structures need to allocate and release memory.
    133    The allocation/release functions must be provided by the caller.
    134    The Alloc_Fn_t function must allocate a chunk of memory of size szB.
    135    cc is the Cost Centre for this allocated memory. This constant string
    136    is used to provide Valgrind's heap profiling, activated by
    137    --profile-heap=no|yes.
    138    The corresponding Free_Fn_t frees the memory chunk p. */
    139 
    140 typedef void* (*Alloc_Fn_t)       ( const HChar* cc, SizeT szB );
    141 typedef void  (*Free_Fn_t)        ( void* p );
    142 
    143 /* An abstraction of syscall return values.
    144    Linux/MIPS32 and Linux/MIPS64:
    145       When _isError == False,
    146          _val and possible _valEx hold the return value.  Whether
    147          _valEx actually holds a valid value depends on which syscall
    148          this SysRes holds of the result of.
    149       When _isError == True,
    150          _val holds the error code.
    151 
    152    Linux/other:
    153       When _isError == False,
    154          _val holds the return value.
    155       When _isError == True,
    156          _val holds the error code.
    157 
    158    Darwin:
    159       Interpretation depends on _mode:
    160       MACH, MDEP:
    161          these can never 'fail' (apparently).  The result of the
    162          syscall is a single host word, _wLO.
    163       UNIX:
    164          Can record a double-word error or a double-word result:
    165          When _mode is SysRes_UNIX_OK,  _wHI:_wLO holds the result.
    166          When _mode is SysRes_UNIX_ERR, _wHI:_wLO holds the error code.
    167          Probably the high word of an error is always ignored by
    168          userspace, but we have to record it, so that we can correctly
    169          update both {R,E}DX and {R,E}AX (in guest state) given a SysRes,
    170          if we're required to.
    171 
    172    Solaris:
    173       When _isError == False,
    174          _val and _val2 hold the return value.
    175       When _isError == True,
    176          _val holds the error code.
    177 */
    178 #if defined(VGP_mips32_linux) || defined(VGP_mips64_linux)
    179 typedef
    180    struct {
    181       Bool  _isError;
    182       UWord _val;
    183       UWord _valEx;
    184    }
    185    SysRes;
    186 
    187 #elif defined(VGO_linux) \
    188       && !defined(VGP_mips32_linux) && !defined(VGP_mips64_linux)
    189 typedef
    190    struct {
    191       Bool  _isError;
    192       UWord _val;
    193    }
    194    SysRes;
    195 
    196 #elif defined(VGO_darwin)
    197 typedef
    198    enum {
    199       SysRes_MACH=40,  // MACH, result is _wLO
    200       SysRes_MDEP,     // MDEP, result is _wLO
    201       SysRes_UNIX_OK,  // UNIX, success, result is _wHI:_wLO
    202       SysRes_UNIX_ERR  // UNIX, error,   error  is _wHI:_wLO
    203    }
    204    SysResMode;
    205 typedef
    206    struct {
    207       UWord _wLO;
    208       UWord _wHI;
    209       SysResMode _mode;
    210    }
    211    SysRes;
    212 
    213 #elif defined(VGO_solaris)
    214 typedef
    215    struct {
    216       UWord _val;
    217       UWord _val2;
    218       Bool  _isError;
    219    }
    220    SysRes;
    221 
    222 #else
    223 #  error "Unknown OS"
    224 #endif
    225 
    226 
    227 /* ---- And now some basic accessor functions for it. ---- */
    228 
    229 #if defined(VGP_mips32_linux) || defined(VGP_mips64_linux)
    230 
    231 static inline Bool sr_isError ( SysRes sr ) {
    232    return sr._isError;
    233 }
    234 static inline UWord sr_Res ( SysRes sr ) {
    235    return sr._isError ? 0 : sr._val;
    236 }
    237 static inline UWord sr_ResEx ( SysRes sr ) {
    238    return sr._isError ? 0 : sr._valEx;
    239 }
    240 static inline UWord sr_Err ( SysRes sr ) {
    241    return sr._isError ? sr._val : 0;
    242 }
    243 static inline Bool sr_EQ ( UInt sysno, SysRes sr1, SysRes sr2 ) {
    244    /* This uglyness of hardcoding syscall numbers is necessary to
    245       avoid having this header file be dependent on
    246       include/vki/vki-scnums-mips{32,64}-linux.h.  It seems pretty
    247       safe given that it is inconceivable that the syscall numbers
    248       for such simple syscalls would ever change.  To make it
    249       really safe, coregrind/m_vkiscnums.c static-asserts that these
    250       syscall numbers haven't changed, so that the build wil simply
    251       fail if they ever do. */
    252 #  if defined(VGP_mips32_linux)
    253    const UInt __nr_Linux = 4000;
    254    const UInt __nr_pipe  = __nr_Linux + 42;
    255    const UInt __nr_pipe2 = __nr_Linux + 328;
    256 #  else
    257    const UInt __nr_Linux = 5000;
    258    const UInt __nr_pipe  = __nr_Linux + 21;
    259    const UInt __nr_pipe2 = __nr_Linux + 287;
    260 #  endif
    261    Bool useEx = sysno == __nr_pipe || sysno == __nr_pipe2;
    262    return sr1._val == sr2._val
    263           && (useEx ? (sr1._valEx == sr2._valEx) : True)
    264           && sr1._isError == sr2._isError;
    265 }
    266 
    267 #elif defined(VGO_linux) \
    268       && !defined(VGP_mips32_linux) && !defined(VGP_mips64_linux)
    269 
    270 static inline Bool sr_isError ( SysRes sr ) {
    271    return sr._isError;
    272 }
    273 static inline UWord sr_Res ( SysRes sr ) {
    274    return sr._isError ? 0 : sr._val;
    275 }
    276 static inline UWord sr_Err ( SysRes sr ) {
    277    return sr._isError ? sr._val : 0;
    278 }
    279 static inline Bool sr_EQ ( UInt sysno, SysRes sr1, SysRes sr2 ) {
    280    /* sysno is ignored for Linux/not-MIPS */
    281    return sr1._val == sr2._val
    282           && sr1._isError == sr2._isError;
    283 }
    284 
    285 #elif defined(VGO_darwin)
    286 
    287 static inline Bool sr_isError ( SysRes sr ) {
    288    switch (sr._mode) {
    289       case SysRes_UNIX_ERR:
    290          return True;
    291       /* should check tags properly and assert here, but we can't here */
    292       case SysRes_MACH:
    293       case SysRes_MDEP:
    294       case SysRes_UNIX_OK:
    295       default:
    296          return False;
    297    }
    298 }
    299 
    300 static inline UWord sr_Res ( SysRes sr ) {
    301    switch (sr._mode) {
    302       case SysRes_MACH:
    303       case SysRes_MDEP:
    304       case SysRes_UNIX_OK:
    305          return sr._wLO;
    306       /* should assert, but we can't here */
    307       case SysRes_UNIX_ERR:
    308       default:
    309          return 0;
    310    }
    311 }
    312 
    313 static inline UWord sr_ResHI ( SysRes sr ) {
    314    switch (sr._mode) {
    315       case SysRes_UNIX_OK:
    316          return sr._wHI;
    317       /* should assert, but we can't here */
    318       case SysRes_MACH:
    319       case SysRes_MDEP:
    320       case SysRes_UNIX_ERR:
    321       default:
    322          return 0;
    323    }
    324 }
    325 
    326 static inline UWord sr_Err ( SysRes sr ) {
    327    switch (sr._mode) {
    328       case SysRes_UNIX_ERR:
    329          return sr._wLO;
    330       /* should assert, but we can't here */
    331       case SysRes_MACH:
    332       case SysRes_MDEP:
    333       case SysRes_UNIX_OK:
    334       default:
    335          return 0;
    336    }
    337 }
    338 
    339 static inline Bool sr_EQ ( UInt sysno, SysRes sr1, SysRes sr2 ) {
    340    /* sysno is ignored for Darwin */
    341    return sr1._mode == sr2._mode
    342           && sr1._wLO == sr2._wLO && sr1._wHI == sr2._wHI;
    343 }
    344 
    345 #elif defined(VGO_solaris)
    346 
    347 static inline Bool sr_isError ( SysRes sr ) {
    348    return sr._isError;
    349 }
    350 static inline UWord sr_Res ( SysRes sr ) {
    351    return sr._isError ? 0 : sr._val;
    352 }
    353 static inline UWord sr_ResHI ( SysRes sr ) {
    354    return sr._isError ? 0 : sr._val2;
    355 }
    356 static inline UWord sr_Err ( SysRes sr ) {
    357    return sr._isError ? sr._val : 0;
    358 }
    359 static inline Bool sr_EQ ( UInt sysno, SysRes sr1, SysRes sr2 ) {
    360    /* sysno is ignored for Solaris */
    361    return sr1._val == sr2._val
    362        && sr1._isError == sr2._isError
    363        && (!sr1._isError) ? (sr1._val2 == sr2._val2) : True;
    364 }
    365 
    366 #else
    367 #  error "Unknown OS"
    368 #endif
    369 
    370 
    371 /* ---------------------------------------------------------------------
    372    Miscellaneous (word size, endianness, regparmness, stringification)
    373    ------------------------------------------------------------------ */
    374 
    375 /* Word size: this is going to be either 4 or 8. */
    376 // It should probably be in m_machine.
    377 #define VG_WORDSIZE VEX_HOST_WORDSIZE
    378 
    379 /* Endianness */
    380 #undef VG_BIGENDIAN
    381 #undef VG_LITTLEENDIAN
    382 
    383 #if defined(VGA_x86) || defined(VGA_amd64) || defined (VGA_arm) \
    384     || ((defined(VGA_mips32) || defined(VGA_mips64)) && defined (_MIPSEL)) \
    385     || defined(VGA_arm64)  || defined(VGA_ppc64le)
    386 #  define VG_LITTLEENDIAN 1
    387 #elif defined(VGA_ppc32) || defined(VGA_ppc64be) || defined(VGA_s390x) \
    388       || ((defined(VGA_mips32) || defined(VGA_mips64)) && defined (_MIPSEB))
    389 #  define VG_BIGENDIAN 1
    390 #else
    391 #  error Unknown arch
    392 #endif
    393 
    394 /* Offsetof */
    395 #if !defined(offsetof)
    396 #   define offsetof(type,memb) ((SizeT)(HWord)&((type*)0)->memb)
    397 #endif
    398 
    399 #if !defined(container_of)
    400 #   define container_of(ptr, type, member) ((type *)((char *)(ptr) - offsetof(type, member)))
    401 #endif
    402 
    403 /* Alignment */
    404 /* We use a prefix vg_ for vg_alignof as its behaviour slightly
    405    differs from the standard alignof/gcc defined __alignof__
    406 
    407    vg_alignof returns a "safe" alignement.
    408    "safe" is defined as the alignment chosen by the compiler in
    409    a struct made of a char followed by this type.
    410 
    411       Note that this is not necessarily the "preferred" alignment
    412       for a platform. This preferred alignment is returned by the gcc
    413        __alignof__ and by the standard (in recent standard) alignof.
    414       Compared to __alignof__, vg_alignof gives on some platforms (e.g.
    415       amd64, ppc32, ppc64) a bigger alignment for long double (16 bytes
    416       instead of 8).
    417       On some platforms (e.g. x86), vg_alignof gives a smaller alignment
    418       than __alignof__ for long long and double (4 bytes instead of 8).
    419       If we want to have the "preferred" alignment for the basic types,
    420       then either we need to depend on gcc __alignof__, or on a (too)
    421       recent standard and compiler (implementing <stdalign.h>).
    422 */
    423 #define vg_alignof(_type) (sizeof(struct {char c;_type _t;})-sizeof(_type))
    424 
    425 /* Regparmness */
    426 #if defined(VGA_x86)
    427 #  define VG_REGPARM(n)            __attribute__((regparm(n)))
    428 #elif defined(VGA_amd64) || defined(VGA_ppc32) \
    429       || defined(VGA_ppc64be) || defined(VGA_ppc64le) \
    430       || defined(VGA_arm) || defined(VGA_s390x) \
    431       || defined(VGA_mips32) || defined(VGA_mips64) \
    432       || defined(VGA_arm64)
    433 #  define VG_REGPARM(n)            /* */
    434 #else
    435 #  error Unknown arch
    436 #endif
    437 
    438 /* Macro games */
    439 #define VG_STRINGIFZ(__str)  #__str
    440 #define VG_STRINGIFY(__str)  VG_STRINGIFZ(__str)
    441 
    442 // Where to send bug reports to.
    443 #define VG_BUGS_TO "www.valgrind.org"
    444 
    445 /* Branch prediction hints. */
    446 #if defined(__GNUC__)
    447 #  define LIKELY(x)   __builtin_expect(!!(x), 1)
    448 #  define UNLIKELY(x) __builtin_expect(!!(x), 0)
    449 #else
    450 #  define LIKELY(x)   (x)
    451 #  define UNLIKELY(x) (x)
    452 #endif
    453 
    454 // printf format string checking for gcc.
    455 // This feature has been supported since at least gcc version 2.95.
    456 // For more information about the format attribute, see
    457 // http://gcc.gnu.org/onlinedocs/gcc-4.3.0/gcc/Function-Attributes.html.
    458 #if defined(__GNUC__)
    459 #define PRINTF_CHECK(x, y) __attribute__((format(__printf__, x, y)))
    460 #else
    461 #define PRINTF_CHECK(x, y)
    462 #endif
    463 
    464 // Macro to "cast" away constness (from type const T to type T) without
    465 // GCC complaining about it. This macro should be used RARELY.
    466 // x is expected to have type const T
    467 #define CONST_CAST(T,x)    \
    468    ({                      \
    469       union {              \
    470          const T in;      \
    471          T out;           \
    472       } var = { .in = x }; var.out;  \
    473    })
    474 
    475 /* Some architectures (eg. mips, arm) do not support unaligned memory access
    476    by hardware, so GCC warns about suspicious situations. This macro could
    477    be used to avoid these warnings but only after careful examination. */
    478 #define ASSUME_ALIGNED(D, x)                 \
    479    ({                                        \
    480       union {                                \
    481          void *in;                           \
    482          D out;                              \
    483       } var;                                 \
    484       var.in = (void *) (x); var.out;        \
    485    })
    486 
    487 // Poor man's static assert
    488 #define STATIC_ASSERT(x)  extern int VG_(VG_(VG_(unused)))[(x) ? 1 : -1] \
    489                                      __attribute__((unused))
    490 
    491 #define VG_MAX(a,b) ((a) > (b) ? a : b)
    492 #define VG_MIN(a,b) ((a) < (b) ? a : b)
    493 
    494 #endif /* __PUB_TOOL_BASICS_H */
    495 
    496 /*--------------------------------------------------------------------*/
    497 /*--- end                                                          ---*/
    498 /*--------------------------------------------------------------------*/
    499