On Thu, Jun 13, 2019 at 08:20:59AM -0500, Josh Poimboeuf wrote:
> Objtool currently ignores ___bpf_prog_run() because it doesn't
> understand the jump table. This results in the ORC unwinder not being
> able to unwind through non-JIT BPF code.
>
> Luckily, the BPF jump table resembles a GCC switch jump table, which
> objtool already knows how to read.
>
> Add generic support for reading any static local jump table array named
> "jump_table", and rename the BPF variable accordingly, so objtool can
> generate ORC data for ___bpf_prog_run().
>
> Fixes: d15d356887e7 ("perf/x86: Make perf callchains work without CONFIG_FRAME_POINTER")
> Reported-by: Song Liu <songliubraving@xxxxxx>
> Signed-off-by: Josh Poimboeuf <jpoimboe@xxxxxxxxxx>
> ---
> kernel/bpf/core.c | 5 ++---
> tools/objtool/check.c | 16 ++++++++++++++--
> 2 files changed, 16 insertions(+), 5 deletions(-)
>
> diff --git a/kernel/bpf/core.c b/kernel/bpf/core.c
> index 7c473f208a10..aa546ef7dbdc 100644
> --- a/kernel/bpf/core.c
> +++ b/kernel/bpf/core.c
> @@ -1299,7 +1299,7 @@ static u64 ___bpf_prog_run(u64 *regs, const struct bpf_insn *insn, u64 *stack)
> {
> #define BPF_INSN_2_LBL(x, y) [BPF_##x | BPF_##y] = &&x##_##y
> #define BPF_INSN_3_LBL(x, y, z) [BPF_##x | BPF_##y | BPF_##z] = &&x##_##y##_##z
> - static const void *jumptable[256] = {
> + static const void *jump_table[256] = {
Nack to the change like above and to patches 8 and 9.
Everyone has different stylistic preferences.
My preference is to keep things as they are.
Please respin the rest. We'll take it via bpf tree.
