On Tue, Sep 29, 2020 at 02:42PM +0200, Andrey Konovalov wrote: [...] > > + */ > > + index = (addr - (unsigned long)__kfence_pool) / (PAGE_SIZE * 2) - 1; > > Why do we subtract 1 here? We do have the metadata entry reserved for something? Above the declaration of __kfence_pool it says: * We allocate an even number of pages, as it simplifies calculations to map * address to metadata indices; effectively, the very first page serves as an * extended guard page, but otherwise has no special purpose. Hopefully that clarifies the `- 1` here. [...] > > + /* Allocation and free stack information. */ > > + int num_alloc_stack; > > + int num_free_stack; > > + unsigned long alloc_stack[KFENCE_STACK_DEPTH]; > > + unsigned long free_stack[KFENCE_STACK_DEPTH]; > > It was a concious decision to not use stackdepot, right? Perhaps it > makes sense to document the reason somewhere. Yes; we want to avoid the dynamic allocations that stackdepot does. [...] Thanks, -- Marco
