diff options
| author | Sandipan Das <sandipan@linux.vnet.ibm.com> | 2018-05-24 09:56:50 +0300 |
|---|---|---|
| committer | Daniel Borkmann <daniel@iogearbox.net> | 2018-05-24 10:20:49 +0300 |
| commit | f84192ee00b7d8b3c38545d3a61d4191f80cc81a (patch) | |
| tree | 236e1f0dada1768797eafacdb707fcce1b59ceb9 /tools/bpf/bpftool/xlated_dumper.c | |
| parent | dd0c5f072e650458feb307fe3a8602cc2ec369d4 (diff) | |
| download | linux-f84192ee00b7d8b3c38545d3a61d4191f80cc81a.tar.xz | |
tools: bpftool: resolve calls without using imm field
Currently, we resolve the callee's address for a JITed function
call by using the imm field of the call instruction as an offset
from __bpf_call_base. If bpf_jit_kallsyms is enabled, we further
use this address to get the callee's kernel symbol's name.
For some architectures, such as powerpc64, the imm field is not
large enough to hold this offset. So, instead of assigning this
offset to the imm field, the verifier now assigns the subprog
id. Also, a list of kernel symbol addresses for all the JITed
functions is provided in the program info. We now use the imm
field as an index for this list to lookup a callee's symbol's
address and resolve its name.
Suggested-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Sandipan Das <sandipan@linux.vnet.ibm.com>
Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Diffstat (limited to 'tools/bpf/bpftool/xlated_dumper.c')
| -rw-r--r-- | tools/bpf/bpftool/xlated_dumper.c | 10 |
1 files changed, 9 insertions, 1 deletions
diff --git a/tools/bpf/bpftool/xlated_dumper.c b/tools/bpf/bpftool/xlated_dumper.c index 7a3173b76c16..efdc8fecf2bb 100644 --- a/tools/bpf/bpftool/xlated_dumper.c +++ b/tools/bpf/bpftool/xlated_dumper.c @@ -174,7 +174,11 @@ static const char *print_call_pcrel(struct dump_data *dd, unsigned long address, const struct bpf_insn *insn) { - if (sym) + if (!dd->nr_jited_ksyms) + /* Do not show address for interpreted programs */ + snprintf(dd->scratch_buff, sizeof(dd->scratch_buff), + "%+d", insn->off); + else if (sym) snprintf(dd->scratch_buff, sizeof(dd->scratch_buff), "%+d#%s", insn->off, sym->name); else @@ -203,6 +207,10 @@ static const char *print_call(void *private_data, unsigned long address = dd->address_call_base + insn->imm; struct kernel_sym *sym; + if (insn->src_reg == BPF_PSEUDO_CALL && + (__u32) insn->imm < dd->nr_jited_ksyms) + address = dd->jited_ksyms[insn->imm]; + sym = kernel_syms_search(dd, address); if (insn->src_reg == BPF_PSEUDO_CALL) return print_call_pcrel(dd, sym, address, insn); |