* Masami Hiramatsu <masami.hiramatsu.pt@xxxxxxxxxxx> wrote: > (2013/11/22 11:35), Masami Hiramatsu wrote: > > (2013/11/21 16:29), Ingo Molnar wrote: > >> > >> * Masami Hiramatsu <masami.hiramatsu.pt@xxxxxxxxxxx> wrote: > >> > >>> (2013/11/21 2:36), Frank Ch. Eigler wrote: > >> > >> [ ... ] > >>>> one needs to resort to something like: > >>>> > >>>> # cat /proc/kallsyms | grep ' [tT] ' | while read addr type symbol; do > >>>> perf probe $symbol > >>>> done > >>>> > >>>> then wait for a few hours for that to finish. Then, or while the loop > >>>> is still running, run > >>>> > >>>> # perf record -e 'probe:*' -aR sleep 1 > >>>> > >>>> to take a kernel down. > >>> > >>> Um, indeed, current blacklist is not perfect. [...] > >> > >> Then it needs to be fixed ASAP! > > > > OK, I see. At least the two patches included this series > > should be fixed. :) > > > > And more, I need to test all symbols and drills down. > > OK, what I've found was; > - The functions which can be ftraced look good. > (see tracing/available_filter_functions) > - following functions should not be able to be probed. > - memcpy, memset > - native_load_sp0 and some other native functions (need to be clear) > - restore > - trace_graph_return > - trace_hardirqs_off_thunk, trace_hardirqs_on_thunk > - This list still be not perfect. I just enabled/disabled kprobes > one by one. There might be combined bugs (combination of several > kprobes). > - Some of them are hard to specify by NOKPROBE_SYMBOL because they are > defined in assembly file. > > Anyway, to fix all of them, I think we need file-based blacklist > especially for assembler symbols. assembler symbols shouldn't be particular hard either, just put them into the noprobes section. > For example, we can get all text symbols by below command; > nm some-file.o | grep -i " t " | cut -f3 -d" " > so that we can make a blacklisted-symbol list for the file. > I need to look the Kbuild for how I can do that in Makefile. I think it's generally better to add explicit annotations to the code. Thanks, Ingo _______________________________________________ Virtualization mailing list Virtualization@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linuxfoundation.org/mailman/listinfo/virtualization
