zlib/zlib-valgrind.patch

   1 --- misc/zlib-1.2.3/deflate.c
   2 +++ misc/build/zlib-1.2.3/deflate.c
   3 @@ -288,6 +288,8 @@
   4      s->prev   = (Posf *)  ZALLOC(strm, s->w_size, sizeof(Pos));
   5      s->head   = (Posf *)  ZALLOC(strm, s->hash_size, sizeof(Pos));
   6
   7 +    s->high_water = 0;      /* nothing written to s->window yet */
   8 +
   9      s->lit_bufsize = 1 << (memLevel + 6); /* 16K elements by default */
  10
  11      overlay = (ushf *) ZALLOC(strm, s->lit_bufsize, sizeof(ush)+2);
  12 @@ -1355,6 +1355,40 @@
  13           */
  14
  15      } while (s->lookahead < MIN_LOOKAHEAD && s->strm->avail_in != 0);
  16 +
  17 +    /* If the WIN_INIT bytes after the end of the current data have never been
  18 +     * written, then zero those bytes in order to avoid memory check reports of
  19 +     * the use of uninitialized (or uninitialised as Julian writes) bytes by
  20 +     * the longest match routines.  Update the high water mark for the next
  21 +     * time through here.  WIN_INIT is set to MAX_MATCH since the longest match
  22 +     * routines allow scanning to strstart + MAX_MATCH, ignoring lookahead.
  23 +     */
  24 +    if (s->high_water < s->window_size) {
  25 +        ulg curr = s->strstart + (ulg)(s->lookahead);
  26 +        ulg init;
  27 +
  28 +        if (s->high_water < curr) {
  29 +            /* Previous high water mark below current data -- zero WIN_INIT
  30 +             * bytes or up to end of window, whichever is less.
  31 +             */
  32 +            init = s->window_size - curr;
  33 +            if (init > WIN_INIT)
  34 +                init = WIN_INIT;
  35 +            zmemzero(s->window + curr, (unsigned)init);
  36 +            s->high_water = curr + init;
  37 +        }
  38 +        else if (s->high_water < (ulg)curr + WIN_INIT) {
  39 +            /* High water mark at or above current data, but below current data
  40 +             * plus WIN_INIT -- zero out to current data plus WIN_INIT, or up
  41 +             * to end of window, whichever is less.
  42 +             */
  43 +            init = (ulg)curr + WIN_INIT - s->high_water;
  44 +            if (init > s->window_size - s->high_water)
  45 +                init = s->window_size - s->high_water;
  46 +            zmemzero(s->window + s->high_water, (unsigned)init);
  47 +            s->high_water += init;
  48 +        }
  49 +    }
  50  }
  51
  52  /* ===========================================================================
  53 --- misc/zlib-1.2.3/deflate.h
  54 +++ misc/build/zlib-1.2.3/deflate.h
  55 @@ -260,6 +260,12 @@
  56       * are always zero.
  57       */
  58
  59 +    ulg high_water;
  60 +    /* High water mark offset in window for initialized bytes -- bytes above
  61 +     * this are set to zero in order to avoid memory check warnings when
  62 +     * longest match routines access bytes past the input.  This is then
  63 +     * updated to the new high water mark.
  64 +     */
  65  } FAR deflate_state;
  66
  67  /* Output a byte on the stream.
  68 @@ -278,6 +284,10 @@
  69   * distances are limited to MAX_DIST instead of WSIZE.
  70   */
  71
  72 +#define WIN_INIT MAX_MATCH
  73 +/* Number of bytes after end of data in window to initialize in order to avoid
  74 +   memory checker errors from longest match routines */
  75 +
  76          /* in trees.c */
  77  void _tr_init         OF((deflate_state *s));
  78  int  _tr_tally        OF((deflate_state *s, unsigned dist, unsigned lc));