On Thu, Apr 15, 2021 at 8:41 AM Quentin Monnet <quentin@xxxxxxxxxxxxx> wrote: > > 2021-04-15 16:37 UTC+0200 ~ Daniel Borkmann <daniel@xxxxxxxxxxxxx> > > On 4/15/21 11:32 AM, Jianlin Lv wrote: > >> For debugging JITs, dumping the JITed image to kernel log is discouraged, > >> "bpftool prog dump jited" is much better way to examine JITed dumps. > >> This patch get rid of the code related to bpf_jit_enable=2 mode and > >> update the proc handler of bpf_jit_enable, also added auxiliary > >> information to explain how to use bpf_jit_disasm tool after this change. > >> > >> Signed-off-by: Jianlin Lv <Jianlin.Lv@xxxxxxx> > > Hello, > > For what it's worth, I have already seen people dump the JIT image in > kernel logs in Qemu VMs running with just a busybox, not for kernel > development, but in a context where buiding/using bpftool was not > possible. If building/using bpftool is not possible then majority of selftests won't be exercised. I don't think such environment is suitable for any kind of bpf development. Much so for JIT debugging. While bpf_jit_enable=2 is nothing but the debugging tool for JIT developers. I'd rather nuke that code instead of carrying it from kernel to kernel.
