[petsc-dev] PetscMalloc1() transformation failed on DMDAGetArray()

[Barry Smith]

  Jed

   Seems your transformation failed badly on this nasty stuff  (don’t blame me, I didn’t write the original code). There will be memory corruption right and left




PetscErrorCode  DMDAGetArray(DM da,PetscBool ghosted,void *vptr)
{
  PetscErrorCode ierr;
  PetscInt       j,i,xs,ys,xm,ym,zs,zm;
  char           *iarray_start;
  void           **iptr = (void**)vptr;
  DM_DA          *dd    = (DM_DA*)da->data;

  PetscFunctionBegin;
  PetscValidHeaderSpecific(da,DM_CLASSID,1);
  if (ghosted) {
    for (i=0; i<DMDA_MAX_WORK_ARRAYS; i++) {
      if (dd->arrayghostedin[i]) {
        *iptr                 = dd->arrayghostedin[i];
        iarray_start          = (char*)dd->startghostedin[i];
        dd->arrayghostedin[i] = NULL;
        dd->startghostedin[i] = NULL;

        goto done;
      }
    }
    xs = dd->Xs;
    ys = dd->Ys;
    zs = dd->Zs;
    xm = dd->Xe-dd->Xs;
    ym = dd->Ye-dd->Ys;
    zm = dd->Ze-dd->Zs;
  } else {
    for (i=0; i<DMDA_MAX_WORK_ARRAYS; i++) {
      if (dd->arrayin[i]) {
        *iptr          = dd->arrayin[i];
        iarray_start   = (char*)dd->startin[i];
        dd->arrayin[i] = NULL;
        dd->startin[i] = NULL;

        goto done;
      }
    }
    xs = dd->xs;
    ys = dd->ys;
    zs = dd->zs;
    xm = dd->xe-dd->xs;
    ym = dd->ye-dd->ys;
    zm = dd->ze-dd->zs;
  }

  switch (dd->dim) {
  case 1: {
    void *ptr;

    ierr = PetscMalloc1(xm,&iarray_start);CHKERRQ(ierr);

    ptr   = (void*)(iarray_start - xs*sizeof(PetscScalar));
    *iptr = (void*)ptr;
    break;
  }
  case 2: {
    void **ptr;

    ierr = PetscMalloc1((ym+1)*sizeof(void*)+xm*ym,&iarray_start);CHKERRQ(ierr);

    ptr = (void**)(iarray_start + xm*ym*sizeof(PetscScalar) - ys*sizeof(void*));
    for (j=ys; j<ys+ym; j++) ptr[j] = iarray_start + sizeof(PetscScalar)*(xm*(j-ys) - xs);
    *iptr = (void*)ptr;
    break;
  }