On Mon, Dec 6, 2021 at 10:14 PM Andrii Nakryiko
<andrii.nakryiko@xxxxxxxxx> wrote:
>
> On Mon, Dec 6, 2021 at 3:22 PM Hao Luo <haoluo@xxxxxxxxxx> wrote:
> >
> > This patch introduce a flag MEM_RDONLY to tag a reg value
> > pointing to read-only memory. It makes the following changes:
> >
> > 1. PTR_TO_RDWR_BUF -> PTR_TO_BUF
> > 2. PTR_TO_RDONLY_BUF -> PTR_TO_BUF | MEM_RDONLY
> >
> > Signed-off-by: Hao Luo <haoluo@xxxxxxxxxx>
> > ---
> > include/linux/bpf.h | 8 +++--
> > kernel/bpf/btf.c | 3 +-
> > kernel/bpf/map_iter.c | 4 +--
> > kernel/bpf/verifier.c | 76 +++++++++++++++++++++++----------------
> > net/core/bpf_sk_storage.c | 2 +-
> > net/core/sock_map.c | 2 +-
> > 6 files changed, 55 insertions(+), 40 deletions(-)
> >
>
> [...]
>
> > static bool arg_type_may_be_refcounted(enum bpf_arg_type type)
> > {
> > return type == ARG_PTR_TO_SOCK_COMMON;
> > @@ -541,8 +546,7 @@ static const char *reg_type_str(enum bpf_reg_type type)
> > [PTR_TO_BTF_ID] = "ptr_",
> > [PTR_TO_PERCPU_BTF_ID] = "percpu_ptr_",
> > [PTR_TO_MEM] = "mem",
> > - [PTR_TO_RDONLY_BUF] = "rdonly_buf",
> > - [PTR_TO_RDWR_BUF] = "rdwr_buf",
> > + [PTR_TO_BUF] = "rdwr_buf",
>
> super misleading if it's actually read-only...
>
True. :)
I will have it fixed in v2. See the reply on patch 4/9 for a potential solution.
> > [PTR_TO_FUNC] = "func",
> > [PTR_TO_MAP_KEY] = "map_key",
> > };
>
> [...]
