On Wed, Aug 26, 2020 at 10:25:55PM -0700, Andrii Nakryiko wrote: > On Wed, Aug 26, 2020 at 9:06 AM Carlos Neira <cneirabustos@xxxxxxxxx> wrote: > > > > In multi-threaded applications bpf_get_current_comm is returning per-thread > > names, this helper will return comm from real_parent. > > This makes a difference for some Java applications, where get_current_comm is > > returning per-thread names, but get_current_pcomm will return "java". > > > > Why not bpf_probe_read_kernel_str(dst, 16, task->real_parent->comm) > for fentry/fexit/tp_btf/etc BTF-aware BPF programs or > BPF_CORE_READ_STR_INTO(dst, task, real_parent, comm) for any BPF > program that has bpf_probe_read_kernel[_str]() (which is pretty much > every BPF program nowadays, I think)? > > Yes, CONFIG_DEBUG_INFO_BTF=y Kconfig is a requirement, but it's a good > idea to have that if you are using BPF anyways. > > > Signed-off-by: Carlos Neira <cneirabustos@xxxxxxxxx> > > --- > > include/linux/bpf.h | 1 + > > include/uapi/linux/bpf.h | 15 ++++- > > kernel/bpf/core.c | 1 + > > kernel/bpf/helpers.c | 28 +++++++++ > > kernel/trace/bpf_trace.c | 2 + > > tools/include/uapi/linux/bpf.h | 15 ++++- > > .../selftests/bpf/prog_tests/current_pcomm.c | 57 +++++++++++++++++++ > > .../selftests/bpf/progs/test_current_pcomm.c | 17 ++++++ > > 8 files changed, 134 insertions(+), 2 deletions(-) > > create mode 100644 tools/testing/selftests/bpf/prog_tests/current_pcomm.c > > create mode 100644 tools/testing/selftests/bpf/progs/test_current_pcomm.c > > > > [...] Thanks Andrii, I'll use bpf_probe_read_kernel_str(dst, 16, task->real_parent->comm), I was not aware of that. Bests!.
