Hi, On 2022-02-04 10:57:42 -0800, Song Liu wrote: > From: Song Liu <songliubraving@xxxxxx> > > Use bpf_jit_binary_pack_alloc in x86_64 jit. The jit engine first writes > the program to the rw buffer. When the jit is done, the program is copied > to the final location with bpf_jit_binary_pack_finalize. > > Note that we need to do bpf_tail_call_direct_fixup after finalize. > Therefore, the text_live = false logic in __bpf_arch_text_poke is no > longer needed. I think this broke bpf_jit_enable = 2. I just tried to use that, to verify I didn't break tools/bpf/bpf_jit_disasm, and I just see output like Jul 02 18:34:40 awork3 kernel: flen=142 proglen=735 pass=5 image=00000000d076e0db from=sshd pid=440127 Jul 02 18:34:40 awork3 kernel: JIT code: 00000000: cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc Jul 02 18:34:40 awork3 kernel: JIT code: 00000010: cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc Jul 02 18:34:40 awork3 kernel: JIT code: 00000020: cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc Jul 02 18:34:40 awork3 kernel: JIT code: 00000030: cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc ... while bpftool keeps showing reasonable content. The 'cc' content only started with a later commit, but I think this is the commit that broke bpf_jit_enable == 2. At the time bpf_jit_dump() is called bpf_jit_binary_pack_alloc() pointed image to ro_header->image, but that's not yet written to, because bpf_jit_binary_pack_finalize() hasn't been called. Greetings, Andres Freund
