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* fixed overflow when reusing a memory block for fixed size chunks

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This commit is contained in:
peter 2004-12-19 13:45:56 +00:00
parent 611897b76b
commit 2e52bf2824
1 changed files with 20 additions and 6 deletions
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26
rtl/inc/heap.inc
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@ -728,16 +728,23 @@ function alloc_oschunk(blockindex, size: ptrint): pointer;
var
pmc : pmemchunk_fixed;
pmcv : pmemchunk_var;
minsize,
maxsize,
i, count : ptrint;
chunksize : ptrint;
begin
{ increase size by size needed for os block header }
size := size + sizeof(toschunk);
minsize := size + sizeof(toschunk);
if blockindex<>0 then
maxsize := (size * $ffff) + sizeof(toschunk)
else
maxsize := high(ptrint);
{ blocks available in freelist? }
result := freeoslist;
while result <> nil do
begin
if poschunk(result)^.size > size then
if (poschunk(result)^.size >= minsize) and
(poschunk(result)^.size <= maxsize) then
begin
size := poschunk(result)^.size;
remove_from_oslist(poschunk(result));
@ -748,11 +755,11 @@ begin
if result = nil then
begin
{$ifdef DUMPGROW}
writeln('growheap(',size,') allocating ',(size+$ffff) and $ffff0000);
writeln('growheap(',size,') allocating ',(size+sizeof(toschunk)+$ffff) and $ffff0000);
DumpBlocks;
{$endif}
{ allocate by 64K size }
size := (size+$ffff) and not $ffff;
size := (size+sizeof(toschunk)+$ffff) and not $ffff;
{ allocate smaller blocks for fixed-size chunks }
if blockindex<>0 then
begin
@ -800,9 +807,13 @@ begin
inc(result, sizeof(toschunk));
if blockindex<>0 then
begin
{ chop os chunk in fixedsize parts }
{ chop os chunk in fixedsize parts,
maximum of $ffff elements are allowed, otherwise
there will be an overflow }
chunksize := blockindex shl blockshr;
count := (size-sizeof(toschunk)) div chunksize;
if count>$ffff then
HandleError(204);
pmc := pmemchunk_fixed(result);
pmc^.prev_fixed := nil;
i := 0;
@ -1275,7 +1286,10 @@ end;
{
$Log$
Revision 1.40 2004-11-26 22:22:58 peter
Revision 1.41 2004-12-19 13:45:56 peter
* fixed overflow when reusing a memory block for fixed size chunks
Revision 1.40 2004/11/26 22:22:58 peter
* fix currheapused
Revision 1.39 2004/11/22 22:26:21 peter