On Thu, May 23, 2019 at 10:24:13AM -0500, Josh Poimboeuf wrote: > Here's the latest version which should fix it in all cases (based on > tip/master): > > https://git.kernel.org/pub/scm/linux/kernel/git/jpoimboe/linux.git/commit/?h=bpf-orc-fix That patch suffers an inconsitency, the comment states: 'if they have "jump_table" in the name' while the actual code implements: 'if the name starts with "jump_table"' Other than that, I suppose that works just fine ;-) > There's no need to put special cases in the FP unwinder when we can > instead just fix the frame pointer usage in the JIT code. > > For ORC, I'm thinking we may be able to just require that all generated > code (BPF and others) always use frame pointers. Then when ORC doesn't > recognize a code address, it could try using the frame pointer as a > fallback. Yes, this seems like a sensible approach. We'd also have to audit the ftrace and kprobe trampolines, IIRC they only do framepointer setup for CONFIG_FRAME_POINTER currently, which should be easy to fix (after the patches I have to fix the FP generation in the first place: https://git.kernel.org/pub/scm/linux/kernel/git/peterz/queue.git/log/?h=x86/wip )
