On Mon, Sep 18, 2023 at 3:41 PM Alexei Starovoitov
<alexei.starovoitov@xxxxxxxxx> wrote:
>
> On Mon, Sep 18, 2023 at 6:25 AM Eric Dumazet <edumazet@xxxxxxxxxx> wrote:
> >
> > On Sat, Sep 16, 2023 at 6:59 PM Alexei Starovoitov
> > <alexei.starovoitov@xxxxxxxxx> wrote:
> > >
> > > Hi David, hi Jakub, hi Paolo, hi Eric,
> > >
> > > The following pull-request contains BPF updates for your *net-next* tree.
> > >
> > > We've added 73 non-merge commits during the last 9 day(s) which contain
> > > a total of 79 files changed, 5275 insertions(+), 600 deletions(-).
> > >
> > > The main changes are:
> > >
> > > 1) Basic BTF validation in libbpf, from Andrii Nakryiko.
> > >
> > > 2) bpf_assert(), bpf_throw(), exceptions in bpf progs, from Kumar Kartikeya Dwivedi.
> > >
> > > 3) next_thread cleanups, from Oleg Nesterov.
> > >
> > > 4) Add mcpu=v4 support to arm32, from Puranjay Mohan.
> > >
> > > 5) Add support for __percpu pointers in bpf progs, from Yonghong Song.
> > >
> > > 6) Fix bpf tailcall interaction with bpf trampoline, from Leon Hwang.
> > >
> > > 7) Raise irq_work in bpf_mem_alloc while irqs are disabled to improve refill probabablity, from Hou Tao.
> > >
> > > Please consider pulling these changes from:
> > >
> > > git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next.git
> > >
> >
> > This might have been raised already, but bpf on x86 now depends on
> > CONFIG_UNWINDER_ORC ?
> >
> > $ grep CONFIG_UNWINDER_ORC .config
> > # CONFIG_UNWINDER_ORC is not set
> >
> > $ make ...
> > arch/x86/net/bpf_jit_comp.c:3022:58: error: no member named 'sp' in
> > 'struct unwind_state'
> > if (!addr || !consume_fn(cookie, (u64)addr,
> > (u64)state.sp, (u64)state.bp))
> > ~~~~~ ^
> > 1 error generated.
>
> Kumar,
> can probably explain better,
> but no the bpf as whole doesn't depend.
> One feature needs either ORC or frame unwinder.
> It won't work with unwinder_guess.
> The build error is a separate issue.
> It hasn't been reported before.
In my builds, I do have CONFIG_UNWINDER_FRAME_POINTER=y
$ grep UNWIND .config
# CONFIG_UNWINDER_ORC is not set
CONFIG_UNWINDER_FRAME_POINTER=y
I note state.sp is only available to CONFIG_UNWINDER_ORC
arch/x86/include/asm/unwind.h
#if defined(CONFIG_UNWINDER_ORC)
bool signal, full_regs;
unsigned long sp, bp, ip;
struct pt_regs *regs, *prev_regs;
#elif defined(CONFIG_UNWINDER_FRAME_POINTER)
bool got_irq;
unsigned long *bp, *orig_sp, ip; // this is orig_sp , not sp.
...
