On Fri, 11 Jul 2014, Masami Hiramatsu wrote: > >> I did some testing with kpatch and I found one minor issue. The > >> dynamically > >> allocated trampoline seems to confuse dump_stack() somewhat. > >> > >> I added a dump_stack() call in my ftrace_ops callback function > >> (kpatch_ftrace_handler) which had a filter on meminfo_proc_show(). > > > > Interesting. Are you using dwarf2 unwinder for stack dumping by any > > chance? It seems to get things right here. Will look into it more > > tomorrow. > > Hmm, can dwarf2 unwinder work on the trampoline method? Since the > trampoline just a copy of instructions which will not have CFI(which is > stored in dwarf section), I guess it may not work... Frame pointer (push > bp and save sp to bp on the entry) can work anyway.
That was exactly my idea and that's why I asked, thanks for confirming. I am afraid we'll have to declare dynamic trampolines incompatible with drawf2 stack dumping. -- Jiri Kosina SUSE Labs -- 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/
