Jean-Yves Migeon <jeanyves.mig...@free.fr> wrote: > On 18.04.2011 05:04, Mindaugas Rasiukevicius wrote: > > Module Name: src > > Committed By: rmind > > Date: Mon Apr 18 03:04:31 UTC 2011 > > > > Modified Files: > > src/sys/arch/xen/xen: balloon.c > > > > Log Message: > > balloon_xenbus_attach: use KM_SLEEP for allocation. > > > > Note: please do not use KM_NOSLEEP. > > Ah yes, forgot about this one, thanks. > > Although I am still unsure about the check, in-kernel NULL deref is... > problematic. > > I am not so sure whether it is safe to assume non-NULL return if caller > can sleep. It's something that ought to be specified for all available > memoryallocators(9) especially as the code behind can evolve (hey, Lars > :) ). >
We used to check the return of big size allocations, when kmem(9) could fail even with KM_SLEEP due to KVA starvation. However, pretty much all kernel does not perform checks for smaller allocations and since the bug was fixed - we are no longer checking for big ones as well. This applies to all allocators. -- Mindaugas
