From: Alexei Starovoitov <ast@fb.com>
To: Andrii Nakryiko <andrii.nakryiko@gmail.com>,
Martin KaFai Lau <kafai@fb.com>
Cc: bpf <bpf@vger.kernel.org>, Alexei Starovoitov <ast@kernel.org>,
Daniel Borkmann <daniel@iogearbox.net>,
Kernel Team <kernel-team@fb.com>,
Networking <netdev@vger.kernel.org>
Subject: Re: [PATCH bpf-next 04/15] bpf: Support bpf program calling kernel function
Date: Thu, 18 Mar 2021 18:51:49 -0700 [thread overview]
Message-ID: <70f08dbd-94d2-79ed-d764-0849d45f662b@fb.com> (raw)
In-Reply-To: <CAEf4Bzb-AmXvV+v-ByGH7iUUG7iLdFxWeY1CJGB7xKHxuABWUg@mail.gmail.com>
On 3/18/21 6:03 PM, Andrii Nakryiko wrote:
>> + desc->imm = BPF_CAST_CALL(addr) - __bpf_call_base;
> Is this difference guaranteed to always fit within s32?
>
we have this restriction in many places: JIT, dispatcher, trampoline,
and bpf interpreter.
Modules and kernel .text are in the same 4G for the same reason:
performance.
next prev parent reply other threads:[~2021-03-19 1:52 UTC|newest]
Thread overview: 49+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-03-16 1:13 [PATCH bpf-next 00/15] Support calling kernel function Martin KaFai Lau
2021-03-16 1:13 ` [PATCH bpf-next 01/15] bpf: Simplify freeing logic in linfo and jited_linfo Martin KaFai Lau
2021-03-16 1:13 ` [PATCH bpf-next 02/15] bpf: btf: Support parsing extern func Martin KaFai Lau
2021-03-18 22:53 ` Andrii Nakryiko
2021-03-18 23:39 ` Martin KaFai Lau
2021-03-19 4:13 ` Andrii Nakryiko
2021-03-19 5:29 ` Martin KaFai Lau
2021-03-19 21:27 ` Andrii Nakryiko
2021-03-19 22:19 ` Martin KaFai Lau
2021-03-19 22:29 ` Andrii Nakryiko
2021-03-19 22:45 ` Martin KaFai Lau
2021-03-19 23:02 ` Andrii Nakryiko
2021-03-20 0:13 ` Martin KaFai Lau
2021-03-20 17:18 ` Andrii Nakryiko
2021-03-23 4:55 ` Martin KaFai Lau
2021-03-16 1:13 ` [PATCH bpf-next 03/15] bpf: Refactor btf_check_func_arg_match Martin KaFai Lau
2021-03-18 23:32 ` Andrii Nakryiko
2021-03-19 19:32 ` Martin KaFai Lau
2021-03-19 21:51 ` Andrii Nakryiko
2021-03-20 0:10 ` Alexei Starovoitov
2021-03-20 17:13 ` Andrii Nakryiko
2021-03-16 1:14 ` [PATCH bpf-next 04/15] bpf: Support bpf program calling kernel function Martin KaFai Lau
2021-03-19 1:03 ` Andrii Nakryiko
2021-03-19 1:51 ` Alexei Starovoitov [this message]
2021-03-19 19:47 ` Martin KaFai Lau
2021-03-16 1:14 ` [PATCH bpf-next 05/15] bpf: Support kernel function call in x86-32 Martin KaFai Lau
2021-03-16 1:14 ` [PATCH bpf-next 06/15] tcp: Rename bictcp function prefix to cubictcp Martin KaFai Lau
2021-03-16 1:14 ` [PATCH bpf-next 07/15] bpf: tcp: White list some tcp cong functions to be called by bpf-tcp-cc Martin KaFai Lau
2021-03-19 1:19 ` Andrii Nakryiko
2021-03-16 1:14 ` [PATCH bpf-next 08/15] libbpf: Refactor bpf_object__resolve_ksyms_btf_id Martin KaFai Lau
2021-03-19 2:53 ` Andrii Nakryiko
2021-03-16 1:14 ` [PATCH bpf-next 09/15] libbpf: Refactor codes for finding btf id of a kernel symbol Martin KaFai Lau
2021-03-19 3:14 ` Andrii Nakryiko
2021-03-16 1:14 ` [PATCH bpf-next 10/15] libbpf: Rename RELO_EXTERN to RELO_EXTERN_VAR Martin KaFai Lau
2021-03-19 3:15 ` Andrii Nakryiko
2021-03-16 1:14 ` [PATCH bpf-next 11/15] libbpf: Record extern sym relocation first Martin KaFai Lau
2021-03-19 3:16 ` Andrii Nakryiko
2021-03-16 1:14 ` [PATCH bpf-next 12/15] libbpf: Support extern kernel function Martin KaFai Lau
2021-03-19 4:11 ` Andrii Nakryiko
2021-03-19 5:06 ` Martin KaFai Lau
2021-03-19 21:38 ` Andrii Nakryiko
2021-03-16 1:14 ` [PATCH bpf-next 13/15] bpf: selftests: Rename bictcp to bpf_cubic Martin KaFai Lau
2021-03-19 4:14 ` Andrii Nakryiko
2021-03-16 1:15 ` [PATCH bpf-next 14/15] bpf: selftest: bpf_cubic and bpf_dctcp calling kernel functions Martin KaFai Lau
2021-03-19 4:15 ` Andrii Nakryiko
2021-03-16 1:15 ` [PATCH bpf-next 15/15] bpf: selftest: Add kfunc_call test Martin KaFai Lau
2021-03-16 3:39 ` kernel test robot
2021-03-19 4:21 ` Andrii Nakryiko
2021-03-19 5:40 ` Martin KaFai Lau
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