On Wed, Nov 14, 2007 at 03:10:13PM -0800, David Miller wrote: > From: Matt Mackall <[EMAIL PROTECTED]> > Date: Wed, 14 Nov 2007 16:53:36 -0600 > > > He hit the bug using SLOB and there are no kmem (or any other) caches > > in SLOB. > > That's unfortunate, is there any user tracking facility at > all?
No, the usual strategy for debugging problems -outside- SLOB is to switch to another allocator with more extensive debugging facilities. It is of course possible to add redzoning, last user, etc., but there aren't many advantages to implementing these in SLOB compared to switching allocators, unless the bug disappears in those other allocators. In the case of random pointer fandango, such bugs are likely to disappear when you turn on debugging anyway. The most likely thing you'll hit in SLOB vs SLUB/SLAB is that SLOB doesn't hand back power-of-two allocations for kmalloc. Instead, it has 2-byte granularity on most machines. So small pointer overruns on kmalloced objects will be somewhat more visible in SLOB than SLAB/SLUB. I don't think SLAB/SLUB debugging can detect overruns inside the not-requested-but-still-allocated region of objects. I've implemented redzoning and various other debugging checks for earlier versions of SLOB to find problems -in- the allocator, but those won't apply to current SLOB (which can be considered v2). -- Mathematics is the supreme nostalgia of our time. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
