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charset=us-ascii Content-Disposition: inline In-Reply-To: <20240209165745.GB975217@maniforge.lan> X-Rspam-User: X-Stat-Signature: jtep9ga1w59onj4kmjrrrhu6qeihyzr7 X-Rspamd-Server: rspam07 X-Rspamd-Queue-Id: 6CCB580009 X-HE-Tag: 1707500822-480328 X-HE-Meta: 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 2Qm4rvlS 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 X-Bogosity: Ham, tests=bogofilter, spamicity=0.018654, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On Fri, Feb 09, 2024 at 10:57:45AM -0600, David Vernet wrote: > On Tue, Feb 06, 2024 at 02:04:27PM -0800, Alexei Starovoitov wrote: > > From: Alexei Starovoitov > > > > Recognize 'void *p__map' kfunc argument as 'struct bpf_map *p__map'. > > It allows kfunc to have 'void *' argument for maps, since bpf progs > > will call them as: > > struct { > > __uint(type, BPF_MAP_TYPE_ARENA); > > ... > > } arena SEC(".maps"); > > > > bpf_kfunc_with_map(... &arena ...); > > > > Underneath libbpf will load CONST_PTR_TO_MAP into the register via ld_imm64 insn. > > If kfunc was defined with 'struct bpf_map *' it would pass > > the verifier, but bpf prog would need to use '(void *)&arena'. > > Which is not clean. > > > > Signed-off-by: Alexei Starovoitov > > --- > > kernel/bpf/verifier.c | 14 +++++++++++++- > > 1 file changed, 13 insertions(+), 1 deletion(-) > > > > diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c > > index d9c2dbb3939f..db569ce89fb1 100644 > > --- a/kernel/bpf/verifier.c > > +++ b/kernel/bpf/verifier.c > > @@ -10741,6 +10741,11 @@ static bool is_kfunc_arg_ignore(const struct btf *btf, const struct btf_param *a > > return __kfunc_param_match_suffix(btf, arg, "__ign"); > > } > > > > +static bool is_kfunc_arg_map(const struct btf *btf, const struct btf_param *arg) > > +{ > > + return __kfunc_param_match_suffix(btf, arg, "__map"); > > +} > > + > > static bool is_kfunc_arg_alloc_obj(const struct btf *btf, const struct btf_param *arg) > > { > > return __kfunc_param_match_suffix(btf, arg, "__alloc"); > > @@ -11064,7 +11069,7 @@ get_kfunc_ptr_arg_type(struct bpf_verifier_env *env, > > return KF_ARG_PTR_TO_CONST_STR; > > > > if ((base_type(reg->type) == PTR_TO_BTF_ID || reg2btf_ids[base_type(reg->type)])) { > > - if (!btf_type_is_struct(ref_t)) { > > + if (!btf_type_is_struct(ref_t) && !btf_type_is_void(ref_t)) { > > verbose(env, "kernel function %s args#%d pointer type %s %s is not supported\n", > > meta->func_name, argno, btf_type_str(ref_t), ref_tname); > > return -EINVAL; > > @@ -11660,6 +11665,13 @@ static int check_kfunc_args(struct bpf_verifier_env *env, struct bpf_kfunc_call_ > > if (kf_arg_type < 0) > > return kf_arg_type; > > > > + if (is_kfunc_arg_map(btf, &args[i])) { > > + /* If argument has '__map' suffix expect 'struct bpf_map *' */ > > + ref_id = *reg2btf_ids[CONST_PTR_TO_MAP]; > > + ref_t = btf_type_by_id(btf_vmlinux, ref_id); > > + ref_tname = btf_name_by_offset(btf, ref_t->name_off); > > + } > > This is fine, but given that this should only apply to KF_ARG_PTR_TO_BTF_ID, > this seems a bit cleaner, wdyt? > > index ddaf09db1175..998da8b302ac 100644 > --- a/kernel/bpf/verifier.c > +++ b/kernel/bpf/verifier.c > @@ -10741,6 +10741,11 @@ static bool is_kfunc_arg_ignore(const struct btf *btf, const struct btf_param *a > return __kfunc_param_match_suffix(btf, arg, "__ign"); > } > > +static bool is_kfunc_arg_map(const struct btf *btf, const struct btf_param *arg) > +{ > + return __kfunc_param_match_suffix(btf, arg, "__map"); > +} > + > static bool is_kfunc_arg_alloc_obj(const struct btf *btf, const struct btf_param *arg) > { > return __kfunc_param_match_suffix(btf, arg, "__alloc"); > @@ -10910,6 +10915,7 @@ enum kfunc_ptr_arg_type { > KF_ARG_PTR_TO_RB_NODE, > KF_ARG_PTR_TO_NULL, > KF_ARG_PTR_TO_CONST_STR, > + KF_ARG_PTR_TO_MAP, /* pointer to a struct bpf_map */ > }; > > enum special_kfunc_type { > @@ -11064,12 +11070,12 @@ get_kfunc_ptr_arg_type(struct bpf_verifier_env *env, > return KF_ARG_PTR_TO_CONST_STR; > > if ((base_type(reg->type) == PTR_TO_BTF_ID || reg2btf_ids[base_type(reg->type)])) { > - if (!btf_type_is_struct(ref_t)) { > + if (!btf_type_is_struct(ref_t) && !btf_type_is_void(ref_t)) { > verbose(env, "kernel function %s args#%d pointer type %s %s is not supported\n", > meta->func_name, argno, btf_type_str(ref_t), ref_tname); > return -EINVAL; > } > - return KF_ARG_PTR_TO_BTF_ID; > + return is_kfunc_arg_map(meta->btf, &args[argno]) ? KF_ARG_PTR_TO_MAP : KF_ARG_PTR_TO_BTF_ID; Makes sense, but then should I add the following on top: diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index e970d9fd7f32..b524dc168023 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -11088,13 +11088,16 @@ get_kfunc_ptr_arg_type(struct bpf_verifier_env *env, if (is_kfunc_arg_const_str(meta->btf, &args[argno])) return KF_ARG_PTR_TO_CONST_STR; + if (is_kfunc_arg_map(meta->btf, &args[argno])) + return KF_ARG_PTR_TO_MAP; + if ((base_type(reg->type) == PTR_TO_BTF_ID || reg2btf_ids[base_type(reg->type)])) { - if (!btf_type_is_struct(ref_t) && !btf_type_is_void(ref_t)) { + if (!btf_type_is_struct(ref_t)) { verbose(env, "kernel function %s args#%d pointer type %s %s is not supported\n", meta->func_name, argno, btf_type_str(ref_t), ref_tname); return -EINVAL; } - return is_kfunc_arg_map(meta->btf, &args[argno]) ? KF_ARG_PTR_TO_MAP : KF_ARG_PTR_TO_BTF_ID; + return KF_ARG_PTR_TO_BTF_ID; } ?