From: "Alexei Starovoitov" <alexei.starovoitov@gmail.com>
To: <bot+bpf-ci@kernel.org>, <bpf@vger.kernel.org>
Cc: <daniel@iogearbox.net>, <andrii@kernel.org>, <eddyz87@gmail.com>,
<memxor@gmail.com>, <a.s.protopopov@gmail.com>,
<martin.lau@kernel.org>, <yonghong.song@linux.dev>,
<mason@kernel.org>, <ihor.solodrai@linux.dev>
Subject: Re: [PATCH v2 bpf-next 08/13] resolve_btfids: Don't list an error that follows work on an argument
Date: Fri, 13 Nov 2026 16:15:36 +0000 [thread overview]
Message-ID: <DMU7U1PO0XJR.4L9Y1AL5QO42@gmail.com> (raw)
In-Reply-To: <552ca9c7597417c92823f305ed9e41c67c2621674e3b568ffa085ae2e2c28aa5@mail.kernel.org>
On Thu, Nov 12, 2026 at 09:52 PM bot+bpf-ci@kernel.org <bot+bpf-ci@kernel.org> wrote:
>> +void scan_set_proto(struct scan *s, const struct image_func *f, unsigned int pointers, bool effect)
>> +{
>> + struct callee *callee = callee_at(s, f->addr);
>> + unsigned int i;
>> +
>> + callee->effect = effect;
>> + callee->pointers = 0;
>> + for (i = 0; i < s->flow.arch->nr_args; i++)
>> + if (pointers & BIT(i))
>> + callee->pointers |= BIT(s->flow.arch->args[i]);
>> +}
>
> Does this mapping hold when a parameter takes more than one register? Here
> BTF parameter i is mapped straight to arch->args[i], and set_protos() builds
> the mask the same way, without regard to parameter size:
It doesn't. Will fix in v3.
> Would advancing the register index by the size of each parameter,
> (btf__resolve_size() + 7) / 8, work here? Alternatively, could a prototype
> with a struct or union parameter be given up on (cleared)?
Only up to 16 bytes. A bigger struct takes no register on x86-64
and one on arm64. So I'll count registers like bpf_jit_place_args()
and stop the mapping at a bigger parameter.
next prev parent reply other threads:[~2026-11-13 16:15 UTC|newest]
Thread overview: 31+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-11-13 5:08 [PATCH v2 bpf-next 00/13] bpf: fmod_ret for each function that returns errors Alexei Starovoitov
2026-11-13 5:08 ` [PATCH v2 bpf-next 01/13] selftests/bpf: Don't depend on the width of a BTF id in verifier_live_stack Alexei Starovoitov
2026-11-13 11:13 ` Anton Protopopov
2026-11-13 5:08 ` [PATCH v2 bpf-next 02/13] resolve_btfids: Read the code of an ELF file by address Alexei Starovoitov
2026-11-13 5:08 ` [PATCH v2 bpf-next 03/13] resolve_btfids: Describe machine instructions with LLVM's MC layer Alexei Starovoitov
2026-11-13 11:45 ` Anton Protopopov
2026-11-13 5:08 ` [PATCH v2 bpf-next 04/13] resolve_btfids: Find the definitions that reach the return value Alexei Starovoitov
2026-11-13 5:08 ` [PATCH v2 bpf-next 05/13] resolve_btfids: Tag the functions that return errors Alexei Starovoitov
2026-11-13 5:08 ` [PATCH v2 bpf-next 06/13] resolve_btfids: Fold the constants of a select without a branch Alexei Starovoitov
2026-11-13 11:59 ` Anton Protopopov
2026-11-13 5:08 ` [PATCH v2 bpf-next 07/13] resolve_btfids: Say which registers an instruction reads Alexei Starovoitov
2026-11-13 12:03 ` Anton Protopopov
2026-11-13 5:08 ` [PATCH v2 bpf-next 08/13] resolve_btfids: Don't list an error that follows work on an argument Alexei Starovoitov
2026-11-13 5:52 ` bot+bpf-ci
2026-11-13 16:15 ` Alexei Starovoitov [this message]
2026-11-13 12:14 ` Anton Protopopov
2026-11-13 5:08 ` [PATCH v2 bpf-next 09/13] bpf: Allow fmod_ret on tagged functions and check the return value Alexei Starovoitov
2026-11-13 5:52 ` bot+bpf-ci
2026-11-13 16:17 ` Alexei Starovoitov
2026-11-13 12:20 ` Anton Protopopov
2026-11-13 16:17 ` Alexei Starovoitov
2026-11-13 5:08 ` [PATCH v2 bpf-next 10/13] selftests/bpf: Test fmod_ret on tagged functions Alexei Starovoitov
2026-11-13 5:08 ` [PATCH v2 bpf-next 11/13] bpf: Mark the arguments of fmod_ret progs as PTR_UNTRUSTED Alexei Starovoitov
2026-11-13 11:09 ` Anton Protopopov
2026-11-13 16:30 ` Alexei Starovoitov
2026-11-13 5:09 ` [PATCH v2 bpf-next 12/13] bpf: Treat the type of an untrusted pointer as a hint Alexei Starovoitov
2026-11-13 5:52 ` bot+bpf-ci
2026-11-13 16:33 ` Alexei Starovoitov
2026-11-13 5:09 ` [PATCH v2 bpf-next 13/13] selftests/bpf: Test untrusted pointers in fmod_ret progs Alexei Starovoitov
2026-11-13 13:00 ` [PATCH v2 bpf-next 00/13] bpf: fmod_ret for each function that returns errors Anton Protopopov
2026-11-13 16:37 ` Alexei Starovoitov
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