Re: [PATCH 2.6.17-rc6 7/9] Remove some of the kmemleak false positives

[Pekka J Enberg <penberg@cs.Helsinki.FI>]

Hi Catalin,

On Tue, 13 Jun 2006, Catalin Marinas wrote:
> The gc roots are the data and bss sections (and maybe task kernel
> stacks) and all the slab-allocated blocks are scanned if a link to
> them is found from the roots (and all of them are usually scanned). If
> no link is found, they would be reported as memory leaks (and not
> scanned). You can't really avoid the scanning of allocated blocks
> since they may contain pointers to other blocks.

I am not sure you're agreeing or disagreeing :-).  As far as I understood, 
Ingo is worried about:

	struct s { /* some fields */; char *buf; };

	struct s *p = kmalloc(sizeof(struct s) + BUF_SIZE);
	p->buf = p + sizeof(struct s);

Which could lead to false negative due to p->buf pointing to p.  However, 
for us to even _find_ p->buf, we would need an incoming pointer _to_ p 
which makes me think this is not a problem in practice.  Hmm?

					Pekka
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