Hello, On Mon, Jun 28, 2021 at 08:33:11PM -0700, Yonghong Song wrote: > > > On 6/25/21 6:22 PM, Eugene Loh wrote: > > > > On 6/1/21 5:48 PM, Yonghong Song wrote: > > > Could you submit a patch for this? Thanks! > > > > Sure. Thanks for looking at this and sorry about the long delay getting > > back to you. > > > > Could you take a look at the attached, proposed patch? As you see in > > the commit message, I'm unclear about the bpf_get_stack*_pe() variants. > > They might use an earlier construct callchain, and I do not know ho > > init_nr was set for them. > > I think bpf_get_stackid() and __bpf_get_stackid() implementation is correct. > Did you find any issues? > > For bpf_get_stack_pe, see: > > https://lore.kernel.org/bpf/20200723180648.1429892-2-songliubraving@xxxxxx/ > I think you should not change bpf_get_stack() function. > __bpf_get_stack() is used by bpf_get_stack() and bpf_get_stack_pe(). > In bpf_get_stack_pe(), callchain is fetched by perf event infrastructure > if event->attr.sample_type & __PERF_SAMPLE_CALLCHAIN_EARLY is true. > > Just focus on __bpf_get_stack(). We could factor __bpf_get_stackid(), > but unless we have a bug, I didn't see it is necessary. > > It will be good if you can add a test for the change, there is a stacktrace > test prog_tests/stacktrace_map.c, you can take a look, > and you can add a subtest there. > > Next time, you can submit a formal patch with `git send-email ...` to > this alias. This way it is easier to review compared to attachment. Any updates on this? I'm hitting the same issue and found this before sending a fix. Thanks, Namhyung
