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

[Dave Jones]

On Thu, Aug 04, 2005 at 05:56:14PM +0200, Rolf Eike Beer wrote:
 > Am Donnerstag, 4. August 2005 17:40 schrieb Dave Jones:
 > >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).
 > 
 > No, this is how it should have been before. This way it would have been clear 
 > where the magic 4 came from.

It's pointless to fix this, without fixing also CpqTsGetSFQEntry()
...

 > >we're trashing the last 48 bytes of every copy we make.
 > >Does this driver even work ?
 > 
 > No, ulDestPtr ist ULONG* so we increase it by sizeof(ULONG)*16 which is 64. 

Duh, yes.  That is broken on 64-bit however, where it will advance 128 bytes
instead of 64 bytes.

		Dave

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