On Tue, Dec 8, 2015 at 4:24 AM, Alexei Starovoitov <alexei.starovoi...@gmail.com> wrote: > On Mon, Dec 07, 2015 at 05:09:21PM +0100, Dmitry Vyukov wrote: >> > So it would be _awesome_ if we could somehow extend this callchain to >> > include the site that calls call_rcu(). >> >> We have a patch for KASAN in works that adds so-called stack depot >> which allows to map a stack trace onto uint32 id. Then we can plumb > > I was hacking something similar to categorize stack traces with u32 id. > How are you planning to limit the number of such stack traces ? > and what is the interface for user space to get stack trace from an id?
We don't limit number of stack traces. Kernel does not seem to use data-driven recursion extensively, so there is limited number of stacks. Though, probably we will need to strip non-interrupt part for interrupt stacks, otherwise that can produce unbounded number of different stacks. There is no interface for user-space, it is used only inside of kernel to save stacks for memory blocks (rcu callbacks, thread pool items in the future). The design is based on what we successfully and extensively use in user-space sanitizers for years. Current code is here: https://github.com/ramosian-glider/kasan/commit/fb0eefd212366401ed5ad244233ef379a27bfb46 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
