| Message ID | 20221230113832.22938-1-xiangxia.m.yue@gmail.com (mailing list archive) |
|---|---|
| State | Changes Requested |
| Delegated to: | BPF |
| Headers | show |
| Series | [bpf-next] bpf, x86_64: fix JIT to dump the valid insn | expand |
On Fri, Dec 30, 2022 at 3:38 AM <xiangxia.m.yue@gmail.com> wrote: > > From: Tonghao Zhang <xiangxia.m.yue@gmail.com> > > With bpf_jit_binary_pack_finalize invoked, we copy > rw_header to header and then image/insn is valid. > > Write a test BPF prog which include subprog: > > $ llvm-objdump -d subprog.o > Disassembly of section .text: > 0000000000000000 <subprog>: > 0: 18 01 00 00 73 75 62 70 00 00 00 00 72 6f 67 00 r1 = 29114459903653235 ll > 2: 7b 1a f8 ff 00 00 00 00 *(u64 *)(r10 - 8) = r1 > 3: bf a1 00 00 00 00 00 00 r1 = r10 > 4: 07 01 00 00 f8 ff ff ff r1 += -8 > 5: b7 02 00 00 08 00 00 00 r2 = 8 > 6: 85 00 00 00 06 00 00 00 call 6 > 7: 95 00 00 00 00 00 00 00 exit > Disassembly of section raw_tp/sys_enter: > 0000000000000000 <entry>: > 0: 85 10 00 00 ff ff ff ff call -1 > 1: b7 00 00 00 00 00 00 00 r0 = 0 > 2: 95 00 00 00 00 00 00 00 exit > > Without this patch, kernel print message: > [ 580.775387] flen=8 proglen=51 pass=3 image=ffffffffa000c20c from=kprobe-load pid=1643 > [ 580.777236] JIT code: 00000000: cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc > [ 580.779037] JIT code: 00000010: cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc > [ 580.780767] JIT code: 00000020: cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc > [ 580.782568] JIT code: 00000030: cc cc cc > > $ bpf_jit_disasm > 51 bytes emitted from JIT compiler (pass:3, flen:8) > ffffffffa000c20c + <x>: > 0: int3 > 1: int3 > 2: int3 > 3: int3 > 4: int3 > 5: int3 > ... > > To fix this issue: > [ 260.016071] flen=3 proglen=20 pass=1 image=ffffffffa000c11c from=kprobe-load pid=1568 > [ 260.018094] JIT code: 00000000: 0f 1f 44 00 00 66 90 55 48 89 e5 e8 38 00 00 00 > [ 260.020124] JIT code: 00000010: 31 c0 c9 c3 > [ 260.021229] flen=8 proglen=51 pass=1 image=ffffffffa000c164 from=kprobe-load pid=1568 > [ 260.023132] JIT code: 00000000: 0f 1f 44 00 00 66 90 55 48 89 e5 48 81 ec 08 00 > [ 260.025129] JIT code: 00000010: 00 00 48 bf 73 75 62 70 72 6f 67 00 48 89 7d f8 > [ 260.027199] JIT code: 00000020: 48 89 ef 48 83 c7 f8 be 08 00 00 00 e8 9e 19 1d > [ 260.029226] JIT code: 00000030: e1 c9 c3 > > $ bpf_jit_disasm > 51 bytes emitted from JIT compiler (pass:1, flen:8) > ffffffffa000c164 + <x>: > 0: nopl 0x0(%rax,%rax,1) > 5: xchg %ax,%ax > 7: push %rbp > 8: mov %rsp,%rbp > b: sub $0x8,%rsp > 12: movabs $0x676f7270627573,%rdi > 1c: mov %rdi,-0x8(%rbp) > 20: mov %rbp,%rdi > 23: add $0xfffffffffffffff8,%rdi > 27: mov $0x8,%esi > 2c: callq 0xffffffffe11d19cf > 31: leaveq > 32: retq > > $ bpf_jit_disasm > 20 bytes emitted from JIT compiler (pass:1, flen:3) > ffffffffa000c11c + <x>: > 0: nopl 0x0(%rax,%rax,1) > 5: xchg %ax,%ax > 7: push %rbp > 8: mov %rsp,%rbp > b: callq 0x0000000000000048 > 10: xor %eax,%eax > 12: leaveq > 13: retq > > Signed-off-by: Tonghao Zhang <xiangxia.m.yue@gmail.com> > Cc: Alexei Starovoitov <ast@kernel.org> > Cc: Daniel Borkmann <daniel@iogearbox.net> > Cc: Andrii Nakryiko <andrii@kernel.org> > Cc: Martin KaFai Lau <martin.lau@linux.dev> > Cc: Song Liu <song@kernel.org> > Cc: Yonghong Song <yhs@fb.com> > Cc: John Fastabend <john.fastabend@gmail.com> > Cc: KP Singh <kpsingh@kernel.org> > Cc: Stanislav Fomichev <sdf@google.com> > Cc: Hao Luo <haoluo@google.com> > Cc: Jiri Olsa <jolsa@kernel.org> > Cc: Hou Tao <houtao1@huawei.com> > --- > arch/x86/net/bpf_jit_comp.c | 6 +++--- > 1 file changed, 3 insertions(+), 3 deletions(-) > > diff --git a/arch/x86/net/bpf_jit_comp.c b/arch/x86/net/bpf_jit_comp.c > index 36ffe67ad6e5..4e017102cc16 100644 > --- a/arch/x86/net/bpf_jit_comp.c > +++ b/arch/x86/net/bpf_jit_comp.c > @@ -2543,9 +2543,6 @@ struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *prog) > cond_resched(); > } > > - if (bpf_jit_enable > 1) > - bpf_jit_dump(prog->len, proglen, pass + 1, image); > - > if (image) { > if (!prog->is_func || extra_pass) { > /* > @@ -2561,6 +2558,9 @@ struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *prog) > goto out_image; > } > > + if (bpf_jit_enable > 1) > + bpf_jit_dump(prog->len, proglen, pass + 1, image); > + bpf_jit_enable==2 is broken. Please delete it from everywhere including docs. Use bpftool prog dump instead.
On Sat, Dec 31, 2022 at 12:56 AM Alexei Starovoitov <alexei.starovoitov@gmail.com> wrote: > > On Fri, Dec 30, 2022 at 3:38 AM <xiangxia.m.yue@gmail.com> wrote: > > > > From: Tonghao Zhang <xiangxia.m.yue@gmail.com> > > > > With bpf_jit_binary_pack_finalize invoked, we copy > > rw_header to header and then image/insn is valid. > > > > Write a test BPF prog which include subprog: > > > > $ llvm-objdump -d subprog.o > > Disassembly of section .text: > > 0000000000000000 <subprog>: > > 0: 18 01 00 00 73 75 62 70 00 00 00 00 72 6f 67 00 r1 = 29114459903653235 ll > > 2: 7b 1a f8 ff 00 00 00 00 *(u64 *)(r10 - 8) = r1 > > 3: bf a1 00 00 00 00 00 00 r1 = r10 > > 4: 07 01 00 00 f8 ff ff ff r1 += -8 > > 5: b7 02 00 00 08 00 00 00 r2 = 8 > > 6: 85 00 00 00 06 00 00 00 call 6 > > 7: 95 00 00 00 00 00 00 00 exit > > Disassembly of section raw_tp/sys_enter: > > 0000000000000000 <entry>: > > 0: 85 10 00 00 ff ff ff ff call -1 > > 1: b7 00 00 00 00 00 00 00 r0 = 0 > > 2: 95 00 00 00 00 00 00 00 exit > > > > Without this patch, kernel print message: > > [ 580.775387] flen=8 proglen=51 pass=3 image=ffffffffa000c20c from=kprobe-load pid=1643 > > [ 580.777236] JIT code: 00000000: cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc > > [ 580.779037] JIT code: 00000010: cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc > > [ 580.780767] JIT code: 00000020: cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc > > [ 580.782568] JIT code: 00000030: cc cc cc > > > > $ bpf_jit_disasm > > 51 bytes emitted from JIT compiler (pass:3, flen:8) > > ffffffffa000c20c + <x>: > > 0: int3 > > 1: int3 > > 2: int3 > > 3: int3 > > 4: int3 > > 5: int3 > > ... > > > > To fix this issue: > > [ 260.016071] flen=3 proglen=20 pass=1 image=ffffffffa000c11c from=kprobe-load pid=1568 > > [ 260.018094] JIT code: 00000000: 0f 1f 44 00 00 66 90 55 48 89 e5 e8 38 00 00 00 > > [ 260.020124] JIT code: 00000010: 31 c0 c9 c3 > > [ 260.021229] flen=8 proglen=51 pass=1 image=ffffffffa000c164 from=kprobe-load pid=1568 > > [ 260.023132] JIT code: 00000000: 0f 1f 44 00 00 66 90 55 48 89 e5 48 81 ec 08 00 > > [ 260.025129] JIT code: 00000010: 00 00 48 bf 73 75 62 70 72 6f 67 00 48 89 7d f8 > > [ 260.027199] JIT code: 00000020: 48 89 ef 48 83 c7 f8 be 08 00 00 00 e8 9e 19 1d > > [ 260.029226] JIT code: 00000030: e1 c9 c3 > > > > $ bpf_jit_disasm > > 51 bytes emitted from JIT compiler (pass:1, flen:8) > > ffffffffa000c164 + <x>: > > 0: nopl 0x0(%rax,%rax,1) > > 5: xchg %ax,%ax > > 7: push %rbp > > 8: mov %rsp,%rbp > > b: sub $0x8,%rsp > > 12: movabs $0x676f7270627573,%rdi > > 1c: mov %rdi,-0x8(%rbp) > > 20: mov %rbp,%rdi > > 23: add $0xfffffffffffffff8,%rdi > > 27: mov $0x8,%esi > > 2c: callq 0xffffffffe11d19cf > > 31: leaveq > > 32: retq > > > > $ bpf_jit_disasm > > 20 bytes emitted from JIT compiler (pass:1, flen:3) > > ffffffffa000c11c + <x>: > > 0: nopl 0x0(%rax,%rax,1) > > 5: xchg %ax,%ax > > 7: push %rbp > > 8: mov %rsp,%rbp > > b: callq 0x0000000000000048 > > 10: xor %eax,%eax > > 12: leaveq > > 13: retq > > > > Signed-off-by: Tonghao Zhang <xiangxia.m.yue@gmail.com> > > Cc: Alexei Starovoitov <ast@kernel.org> > > Cc: Daniel Borkmann <daniel@iogearbox.net> > > Cc: Andrii Nakryiko <andrii@kernel.org> > > Cc: Martin KaFai Lau <martin.lau@linux.dev> > > Cc: Song Liu <song@kernel.org> > > Cc: Yonghong Song <yhs@fb.com> > > Cc: John Fastabend <john.fastabend@gmail.com> > > Cc: KP Singh <kpsingh@kernel.org> > > Cc: Stanislav Fomichev <sdf@google.com> > > Cc: Hao Luo <haoluo@google.com> > > Cc: Jiri Olsa <jolsa@kernel.org> > > Cc: Hou Tao <houtao1@huawei.com> > > --- > > arch/x86/net/bpf_jit_comp.c | 6 +++--- > > 1 file changed, 3 insertions(+), 3 deletions(-) > > > > diff --git a/arch/x86/net/bpf_jit_comp.c b/arch/x86/net/bpf_jit_comp.c > > index 36ffe67ad6e5..4e017102cc16 100644 > > --- a/arch/x86/net/bpf_jit_comp.c > > +++ b/arch/x86/net/bpf_jit_comp.c > > @@ -2543,9 +2543,6 @@ struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *prog) > > cond_resched(); > > } > > > > - if (bpf_jit_enable > 1) > > - bpf_jit_dump(prog->len, proglen, pass + 1, image); > > - > > if (image) { > > if (!prog->is_func || extra_pass) { > > /* > > @@ -2561,6 +2558,9 @@ struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *prog) > > goto out_image; > > } > > > > + if (bpf_jit_enable > 1) > > + bpf_jit_dump(prog->len, proglen, pass + 1, image); > > + > > bpf_jit_enable==2 is broken. > Please delete it from everywhere including docs. > Use bpftool prog dump instead. Thanks, send v2 soon.
diff --git a/arch/x86/net/bpf_jit_comp.c b/arch/x86/net/bpf_jit_comp.c index 36ffe67ad6e5..4e017102cc16 100644 --- a/arch/x86/net/bpf_jit_comp.c +++ b/arch/x86/net/bpf_jit_comp.c @@ -2543,9 +2543,6 @@ struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *prog) cond_resched(); } - if (bpf_jit_enable > 1) - bpf_jit_dump(prog->len, proglen, pass + 1, image); - if (image) { if (!prog->is_func || extra_pass) { /* @@ -2561,6 +2558,9 @@ struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *prog) goto out_image; } + if (bpf_jit_enable > 1) + bpf_jit_dump(prog->len, proglen, pass + 1, image); + bpf_tail_call_direct_fixup(prog); } else { jit_data->addrs = addrs;