On Tue, Nov 9, 2021 at 9:19 PM Yonghong Song <yhs@xxxxxx> wrote: > > LLVM patches ([1] for clang, [2] and [3] for BPF backend) > added support for btf_type_tag attributes. This patch > added support for the kernel. > > The main motivation for btf_type_tag is to bring kernel > annotations __user, __rcu etc. to btf. With such information > available in btf, bpf verifier can detect mis-usages > and reject the program. For example, for __user tagged pointer, > developers can then use proper helper like bpf_probe_read_kernel() probably meant to write bpf_probe_read_user()? LGTM, otherwise. Acked-by: Andrii Nakryiko <andrii@xxxxxxxxxx> > etc. to read the data. > > BTF_KIND_TYPE_TAG may also useful for other tracing > facility where instead of to require user to specify > kernel/user address type, the kernel can detect it > by itself with btf. > > [1] https://reviews.llvm.org/D111199 > [2] https://reviews.llvm.org/D113222 > [3] https://reviews.llvm.org/D113496 > > Signed-off-by: Yonghong Song <yhs@xxxxxx> > --- > include/uapi/linux/btf.h | 3 ++- > kernel/bpf/btf.c | 14 +++++++++++++- > tools/include/uapi/linux/btf.h | 3 ++- > 3 files changed, 17 insertions(+), 3 deletions(-) > [...]
