Hello, On 11/8/22 6:40 pm, Marco Elver wrote: > On Thu, 11 Aug 2022 at 09:26, Imran Khan <imran.f.khan@xxxxxxxxxx> wrote: >> >> By default kfence allocation can happen for any slab object, whose size >> is up to PAGE_SIZE, as long as that allocation is the first allocation >> after expiration of kfence sample interval. But in certain debugging >> scenarios we may be interested in debugging corruptions involving >> some specific slub objects like dentry or ext4_* etc. In such cases >> limiting kfence for allocations involving only specific slub objects >> will increase the probablity of catching the issue since kfence pool >> will not be consumed by other slab objects. >> >> This patch introduces a sysfs interface '/sys/kernel/slab/<name>/skip_kfence' >> to disable kfence for specific slabs. Having the interface work in this >> way does not impact current/default behavior of kfence and allows us to >> use kfence for specific slabs (when needed) as well. The decision to >> skip/use kfence is taken depending on whether kmem_cache.flags has >> (newly introduced) SLAB_SKIP_KFENCE flag set or not. >> >> Signed-off-by: Imran Khan <imran.f.khan@xxxxxxxxxx> >> --- >> >> This RFC patch is implementing the sysfs work mentioned in [1]. Since the >> approach taken in [1] was not proper, I am sending this RFC patch as a >> separate change. > > This design is much simpler and looks good to me. Feel free to send as > a non-RFC. > Thanks for reviewing this. I have sent non-RFC version of this change. Thanks, -- Imran
