Re: [PATCH 1/2] cpqfc: fix for "Using too much stach" in 2.6 kernel

Dave Jones
2005-08-04T15:41:10Z

On Thu, Aug 04, 2005 at 11:38:30AM +0200, Rolf Eike Beer wrote:
>
> >+ ulFibreFrame = kmalloc((2048/4), GFP_KERNEL);
> The size bug was already found by Dave Jones. This never should be written
> this way (not your fault). The array should have been [2048/sizeof(ULONG)].

wasteful. We only ever use 2048 bytes of this array, so doubling
its size on 64bit is pointless, unless you make changes later on
in the driver. (Which I think don't make sense, as we just copy
32 64byte chunks).

Ermm, actually this looks totally bogus..
CpqTsGetSFQEntry() ...

if( total_bytes <= 2048 )
{
memcpy( ulDestPtr,
&fcChip->SFQ->QEntry[consumerIndex],
64 ); // each SFQ entry is 64 bytes
ulDestPtr += 16; // advance pointer to next 64 byte block
}

we're trashing the last 48 bytes of every copy we make.
Does this driver even work ?

Dave