On Thu, Apr 28, 2022 at 4:17 AM Larysa Zaremba <[email protected]> wrote:
>
> Currently, dumping almost all BTFs specified by id requires
It should and will work only for kernel modules. It won't and
shouldn't work for BTFs coming from BPF programs. We shouldn't blindly
guess and substitute vmlinux BTF as base BTF, let's fetch
bpf_btf_info, check that BTF is from kernel and is not vmlinux, and
only in such case substitute vmlinux BTF as base BTF.
> using the -B option to pass the base BTF. For most cases
> the vmlinux BTF sysfs path should work.
>
> This patch simplifies dumping by ID usage by attempting to
> use vmlinux BTF from sysfs, if the first try of loading BTF by ID
> fails with certain conditions.
>
> Signed-off-by: Larysa Zaremba <[email protected]>
> Reviewed-by: Alexander Lobakin <[email protected]>
> ---
> tools/bpf/bpftool/btf.c | 35 ++++++++++++++++++++++++++---------
> 1 file changed, 26 insertions(+), 9 deletions(-)
>
[...]
On Thu, 28 Apr 2022 21:58:58 -0700 Andrii Nakryiko <[email protected]> wrote:
> On Thu, Apr 28, 2022 at 4:17 AM Larysa Zaremba <[email protected]> wrote:
> >
> > Currently, dumping almost all BTFs specified by id requires
>
> It should and will work only for kernel modules. It won't and
> shouldn't work for BTFs coming from BPF programs. We shouldn't blindly
> guess and substitute vmlinux BTF as base BTF, let's fetch
> bpf_btf_info, check that BTF is from kernel and is not vmlinux, and
> only in such case substitute vmlinux BTF as base BTF.
I agree, this is taken into account in v2
> > using the -B option to pass the base BTF. For most cases
> > the vmlinux BTF sysfs path should work.
> >
> > This patch simplifies dumping by ID usage by attempting to
> > use vmlinux BTF from sysfs, if the first try of loading BTF by ID
> > fails with certain conditions.
> >
> > Signed-off-by: Larysa Zaremba <[email protected]>
> > Reviewed-by: Alexander Lobakin <[email protected]>
> > ---
> > tools/bpf/bpftool/btf.c | 35 ++++++++++++++++++++++++++---------
> > 1 file changed, 26 insertions(+), 9 deletions(-)
> >
Best Regards,
Larysa Zaremba