pike.git/ src/ stralloc.c

2008-06-23

2008-06-23 18:56:08 by Martin Stjernholm <mast@lysator.liu.se>

• e8371ec3f46839f60375eeeb40a68e69e1034dea (43 lines) (+35/-8) ^{[ Show | Annotate ]}
  Branch: 7.9

Fixed allocation bug in init_string_builder_copy. This could cause
memory corruption in String.Buffer when using `+ on overallocated
buffers.

Also ensure proper wide NUL termination in wide string builders.

Added a debug check.

Rev: src/stralloc.c:1.222

2:   || This file is part of Pike. For copyright information see COPYRIGHT.   || Pike is distributed under GPL, LGPL and MPL. See the file COPYING   || for more information. - || $Id: stralloc.c,v 1.221 2008/06/23 16:05:02 mast Exp $ + || $Id: stralloc.c,v 1.222 2008/06/23 18:56:08 mast Exp $   */      #include "global.h"
769:    size_t h=0;    struct pike_string *s2;    + #ifdef PIKE_DEBUG +  if (d_flag) { +  switch (s->size_shift) { +  case 0: +  break; +  +  case 1: +  if(!find_magnitude1(STR1(s),s->len)) +  Pike_fatal ("String %p that should have shift 1 really got 0.\n", s); +  break; +  +  case 2: { +  int m = find_magnitude2 (STR2 (s), s->len); +  if (m != 2) +  Pike_fatal ("String %p that should have shift 2 really got %d.\n", +  s, m); +  break; +  } +  +  default: +  Pike_fatal("ARGHEL! size_shift:%d\n", s->size_shift); +  } +  } + #endif +     len = s->len;    if (s->flags & STRING_NOT_HASHED) {    h = s->hval = do_hash(s);
803:       switch(s->size_shift)    { - #ifdef PIKE_DEBUG +     default: -  + #ifdef PIKE_DEBUG    Pike_fatal("ARGHEL! size_shift:%d\n", s->size_shift); - #endif +        case 2: -  + #endif    switch(find_magnitude2(STR2(s),s->len))    {    case 0:
2201:    s->malloced=256;    s->s=begin_wide_shared_string(256,mag);    s->s->len=0; -  s->s->str[0] = 0; +  low_set_index (s->s, 0, 0);    s->known_shift=0;   }   
2210:    s->malloced=length;    s->s=begin_wide_shared_string(length,mag);    s->s->len=0; -  s->s->str[0] = 0; +  low_set_index (s->s, 0, 0);    s->known_shift=0;   }   
2218:    struct string_builder *from)   {    to->malloced = from->malloced; -  to->s = begin_wide_shared_string (from->s->len, from->s->size_shift); -  MEMCPY (to->s->str, from->s->str, from->s->len << from->s->size_shift); +  to->s = begin_wide_shared_string (from->malloced, from->s->size_shift); +  to->s->len = from->s->len; +  MEMCPY (to->s->str, from->s->str, (from->s->len + 1) << from->s->size_shift);    to->known_shift = from->known_shift;   }   
2997:    s->known_shift=0;    s->s->len=0;    /* Ensure NUL-termination */ -  s->s->str[0] = 0; +  low_set_index (s->s, 0, 0);   }      PMOD_EXPORT void free_string_builder(struct string_builder *s)