From: Andrii Nakryiko <andrii.nakryiko@gmail.com>
To: 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 11/15] libbpf: Record extern sym relocation first
Date: Thu, 18 Mar 2021 20:16:50 -0700 [thread overview]
Message-ID: <CAEf4BzaLcqHEHu506t+Lr1X-d01-D0isxM0NZ56nLnR3bv1eUQ@mail.gmail.com> (raw)
In-Reply-To: <20210316011445.4179633-1-kafai@fb.com>
On Tue, Mar 16, 2021 at 12:02 AM Martin KaFai Lau <kafai@fb.com> wrote:
>
> This patch records the extern sym relocs first before recording
> subprog relocs. The later patch will have relocs for extern
> kernel function call which is also using BPF_JMP | BPF_CALL.
> It will be easier to handle the extern symbols first in
> the later patch.
>
> Signed-off-by: Martin KaFai Lau <kafai@fb.com>
> ---
Looks good, just let's add that tiny helper for cleanliness and to
match what we do for ldimm64
Acked-by: Andrii Nakryiko <andrii@kernel.org>
> tools/lib/bpf/libbpf.c | 50 +++++++++++++++++++++---------------------
> 1 file changed, 25 insertions(+), 25 deletions(-)
>
> diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
> index 8f924aece736..0a60fcb2fba2 100644
> --- a/tools/lib/bpf/libbpf.c
> +++ b/tools/lib/bpf/libbpf.c
> @@ -3416,31 +3416,7 @@ static int bpf_program__record_reloc(struct bpf_program *prog,
>
> reloc_desc->processed = false;
>
> - /* sub-program call relocation */
> - if (insn->code == (BPF_JMP | BPF_CALL)) {
> - if (insn->src_reg != BPF_PSEUDO_CALL) {
> - pr_warn("prog '%s': incorrect bpf_call opcode\n", prog->name);
> - return -LIBBPF_ERRNO__RELOC;
> - }
> - /* text_shndx can be 0, if no default "main" program exists */
> - if (!shdr_idx || shdr_idx != obj->efile.text_shndx) {
> - sym_sec_name = elf_sec_name(obj, elf_sec_by_idx(obj, shdr_idx));
> - pr_warn("prog '%s': bad call relo against '%s' in section '%s'\n",
> - prog->name, sym_name, sym_sec_name);
> - return -LIBBPF_ERRNO__RELOC;
> - }
> - if (sym->st_value % BPF_INSN_SZ) {
> - pr_warn("prog '%s': bad call relo against '%s' at offset %zu\n",
> - prog->name, sym_name, (size_t)sym->st_value);
> - return -LIBBPF_ERRNO__RELOC;
> - }
> - reloc_desc->type = RELO_CALL;
> - reloc_desc->insn_idx = insn_idx;
> - reloc_desc->sym_off = sym->st_value;
> - return 0;
> - }
> -
> - if (!is_ldimm64(insn)) {
> + if (insn->code != (BPF_JMP | BPF_CALL) && !is_ldimm64(insn)) {
> pr_warn("prog '%s': invalid relo against '%s' for insns[%d].code 0x%x\n",
> prog->name, sym_name, insn_idx, insn->code);
> return -LIBBPF_ERRNO__RELOC;
> @@ -3469,6 +3445,30 @@ static int bpf_program__record_reloc(struct bpf_program *prog,
> return 0;
> }
>
> + /* sub-program call relocation */
> + if (insn->code == (BPF_JMP | BPF_CALL)) {
can you please add is_call_insn() helper checking this, similarly to
how we now have is_ldimm64() (should probably be is_ldimm64_insn() for
consistency)
> + if (insn->src_reg != BPF_PSEUDO_CALL) {
> + pr_warn("prog '%s': incorrect bpf_call opcode\n", prog->name);
> + return -LIBBPF_ERRNO__RELOC;
> + }
> + /* text_shndx can be 0, if no default "main" program exists */
> + if (!shdr_idx || shdr_idx != obj->efile.text_shndx) {
> + sym_sec_name = elf_sec_name(obj, elf_sec_by_idx(obj, shdr_idx));
> + pr_warn("prog '%s': bad call relo against '%s' in section '%s'\n",
> + prog->name, sym_name, sym_sec_name);
> + return -LIBBPF_ERRNO__RELOC;
> + }
> + if (sym->st_value % BPF_INSN_SZ) {
> + pr_warn("prog '%s': bad call relo against '%s' at offset %zu\n",
> + prog->name, sym_name, (size_t)sym->st_value);
> + return -LIBBPF_ERRNO__RELOC;
> + }
> + reloc_desc->type = RELO_CALL;
> + reloc_desc->insn_idx = insn_idx;
> + reloc_desc->sym_off = sym->st_value;
> + return 0;
> + }
> +
> if (!shdr_idx || shdr_idx >= SHN_LORESERVE) {
> pr_warn("prog '%s': invalid relo against '%s' in special section 0x%x; forgot to initialize global var?..\n",
> prog->name, sym_name, shdr_idx);
> --
> 2.30.2
>
next prev parent reply other threads:[~2021-03-19 3:18 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
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 [this message]
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
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=CAEf4BzaLcqHEHu506t+Lr1X-d01-D0isxM0NZ56nLnR3bv1eUQ@mail.gmail.com \
--to=andrii.nakryiko@gmail.com \
--cc=ast@kernel.org \
--cc=bpf@vger.kernel.org \
--cc=daniel@iogearbox.net \
--cc=kafai@fb.com \
--cc=kernel-team@fb.com \
--cc=netdev@vger.kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).