From: Andrii Nakryiko <andrii@kernel.org>
To: <bpf@vger.kernel.org>, <ast@kernel.org>, <daniel@iogearbox.net>
Cc: <andrii@kernel.org>, <kernel-team@fb.com>, Tejun Heo <tj@kernel.org>
Subject: [PATCH bpf-next 12/17] bpf: add support for fixed-size memory pointer returns for kfuncs
Date: Thu, 2 Mar 2023 15:50:10 -0800 [thread overview]
Message-ID: <20230302235015.2044271-13-andrii@kernel.org> (raw)
In-Reply-To: <20230302235015.2044271-1-andrii@kernel.org>
Support direct fixed-size (and for now, read-only) memory access when
kfunc's return type is a pointer to non-struct type. Calculate type size
and let BPF program access that many bytes directly. This is crucial for
numbers iterator.
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
---
kernel/bpf/verifier.c | 8 ++++++++
1 file changed, 8 insertions(+)
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index 641a36204493..0ff9dd9170ef 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -10241,6 +10241,14 @@ static int check_kfunc_call(struct bpf_verifier_env *env, struct bpf_insn *insn,
return -EFAULT;
}
} else if (!__btf_type_is_struct(ptr_type)) {
+ if (!meta.r0_size) {
+ __u32 sz;
+
+ if (!IS_ERR(btf_resolve_size(desc_btf, ptr_type, &sz))) {
+ meta.r0_size = sz;
+ meta.r0_rdonly = true;
+ }
+ }
if (!meta.r0_size) {
ptr_type_name = btf_name_by_offset(desc_btf,
ptr_type->name_off);
--
2.30.2
next prev parent reply other threads:[~2023-03-02 23:50 UTC|newest]
Thread overview: 35+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-03-02 23:49 [PATCH bpf-next 00/17] BPF open-coded iterators Andrii Nakryiko
2023-03-02 23:49 ` [PATCH bpf-next 01/17] bpf: improve stack slot state printing Andrii Nakryiko
2023-03-02 23:50 ` [PATCH bpf-next 02/17] bpf: improve regsafe() checks for PTR_TO_{MEM,BUF,TP_BUFFER} Andrii Nakryiko
2023-03-02 23:50 ` [PATCH bpf-next 03/17] selftests/bpf: enhance align selftest's expected log matching Andrii Nakryiko
2023-03-02 23:50 ` [PATCH bpf-next 04/17] bpf: honor env->test_state_freq flag in is_state_visited() Andrii Nakryiko
2023-03-02 23:50 ` [PATCH bpf-next 05/17] selftests/bpf: adjust log_fixup's buffer size for proper truncation Andrii Nakryiko
2023-03-02 23:50 ` [PATCH bpf-next 06/17] bpf: clean up visit_insn()'s instruction processing Andrii Nakryiko
2023-03-02 23:50 ` [PATCH bpf-next 07/17] bpf: fix visit_insn()'s detection of BPF_FUNC_timer_set_callback helper Andrii Nakryiko
2023-03-02 23:50 ` [PATCH bpf-next 08/17] bpf: ensure that r0 is marked scratched after any function call Andrii Nakryiko
2023-03-02 23:50 ` [PATCH bpf-next 09/17] bpf: move kfunc_call_arg_meta higher in the file Andrii Nakryiko
2023-03-02 23:50 ` [PATCH bpf-next 10/17] bpf: mark PTR_TO_MEM as non-null register type Andrii Nakryiko
2023-03-02 23:50 ` [PATCH bpf-next 11/17] bpf: generalize dynptr_get_spi to be usable for iters Andrii Nakryiko
2023-03-02 23:50 ` Andrii Nakryiko [this message]
2023-03-02 23:50 ` [PATCH bpf-next 13/17] bpf: add support for open-coded iterator loops Andrii Nakryiko
2023-03-04 20:02 ` Alexei Starovoitov
2023-03-04 23:27 ` Andrii Nakryiko
2023-03-05 23:46 ` Alexei Starovoitov
2023-03-07 21:54 ` Andrii Nakryiko
2023-03-02 23:50 ` [PATCH bpf-next 14/17] bpf: implement number iterator Andrii Nakryiko
2023-03-04 20:21 ` Alexei Starovoitov
2023-03-04 23:27 ` Andrii Nakryiko
2023-03-05 23:49 ` Alexei Starovoitov
2023-03-02 23:50 ` [PATCH bpf-next 15/17] selftests/bpf: add bpf_for_each(), bpf_for(), and bpf_repeat() macros Andrii Nakryiko
2023-03-04 20:34 ` Alexei Starovoitov
2023-03-04 23:28 ` Andrii Nakryiko
2023-03-06 0:12 ` Alexei Starovoitov
2023-03-07 21:54 ` Andrii Nakryiko
2023-03-02 23:50 ` [PATCH bpf-next 16/17] selftests/bpf: add iterators tests Andrii Nakryiko
2023-03-04 20:39 ` Alexei Starovoitov
2023-03-04 23:29 ` Andrii Nakryiko
2023-03-06 0:14 ` Alexei Starovoitov
2023-03-04 21:09 ` Jiri Olsa
2023-03-04 23:29 ` Andrii Nakryiko
2023-03-02 23:50 ` [PATCH bpf-next 17/17] selftests/bpf: add number iterator tests Andrii Nakryiko
2023-03-04 19:30 ` [PATCH bpf-next 00/17] BPF open-coded iterators patchwork-bot+netdevbpf
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