Bug#487745: epiphany-webkit: crashes on startup

[Sjoerd Simons]

On Tue, Jun 24, 2008 at 08:44:23AM +0200, Mike Hommey wrote:
> Or maybe something like this:
> 
> diff --git a/JavaScriptCore/wtf/FastMalloc.cpp b/JavaScriptCore/wtf/FastMalloc.cpp
> index 8afc70d..496d1ee 100644
> --- a/JavaScriptCore/wtf/FastMalloc.cpp
> +++ b/JavaScriptCore/wtf/FastMalloc.cpp
> @@ -1820,7 +1820,7 @@ static TCMalloc_Central_FreeListPadded central_cache[kNumClasses];
>  
>  // Page-level allocator
>  static SpinLock pageheap_lock = SPINLOCK_INITIALIZER;
> -static void* pageheap_memory[(sizeof(TCMalloc_PageHeap) + sizeof(void*) - 1) / sizeof(void*)];
> +static uint64_t* pageheap_memory[(sizeof(TCMalloc_PageHeap) + sizeof(uint64_t*) - 1) / sizeof(uint64_t*)];
>  static bool phinited = false;

All pointers are the same size and have the same alignment requirements, so
this change doesn't force the compiler to change make pageheap_memory aligned
on 8 bytes. I'm probably missing some trick (not very familiar with C++), but why
not just do:

static TCMalloc_PageHeap pageheap_memory;

static inline TCMalloc_PageHeap* getPageHeap()
{
  return &pageheap_memory;
}

> Where pageheap is a macro for getPageHeap(). So what is actually not
> 64-bit aligned is not allocated through the a dynamic allocator...
> 
> So, I'd say forcing this to be 64-bit aligned should be enough, and the
> above diff should be doing just this.

Forcing the compiler to allign the memory to whatever has the biggest alignment
requirement in the class should fix the problem indeed.

  Sjoerd
-- 
In the next world, you're on your own.