On 05/23/22 at 11:00am, Stephen Brennan wrote: > Baoquan He <bhe@xxxxxxxxxx> writes: > > On 05/16/22 at 05:05pm, Stephen Brennan wrote: > >> The kernel can be configured to contain a lot of introspection or > >> debugging information built-in, such as ORC for unwinding stack traces, > >> BTF for type information, and of course kallsyms. Debuggers could use > >> this information to navigate a core dump or live system, but they need > >> to be able to find it. > >> > >> This patch series adds the necessary symbols into vmcoreinfo, which > >> would allow a debugger to find and interpret the kallsyms table. Using > >> the kallsyms data, the debugger can then lookup any symbol, allowing it > >> to find ORC, BTF, or any other useful data. > >> > >> This would allow a live kernel, or core dump, to be debugged without > >> any DWARF debuginfo. This is useful for many cases: the debuginfo may > >> not have been generated, or you may not want to deploy the large files > >> everywhere you need them. > >> > >> I've demonstrated a proof of concept for this at LSF/MM+BPF during a > >> lighting talk. Using a work-in-progress branch of the drgn debugger, and > >> an extended set of BTF generated by a patched version of dwarves, I've > >> been able to open a core dump without any DWARF info and do basic tasks > >> such as enumerating slab caches, block devices, tasks, and doing > >> backtraces. I hope this series can be a first step toward a new > >> possibility of "DWARFless debugging". > > > > Thanks. Seems no reason to reject, even though I haven't tried drgn. > > And hope it has no security issue, e.g info leakage, at least I don't > > see it has. So, > > > > Acked-by: Baoquan He <bhe@xxxxxxxxxx> > > Thanks Baoquan! I don't believe we have any worries regarding security, > since the kallsyms data itself is already available to root via > /proc/kallsyms, and core dumps should already be treated as highly > sensitive data by anybody handling them. > > Do you know which tree this patch will go through? I would like to ask Andrew to help check and pick this if no concern. Thanks Baoquan _______________________________________________ kexec mailing list kexec@xxxxxxxxxxxxxxxxxxx http://lists.infradead.org/mailman/listinfo/kexec
