From: Jiri Olsa <olsajiri@gmail.com>
To: Andrii Nakryiko <andrii.nakryiko@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>, Alexei Starovoitov <ast@kernel.org>,
Daniel Borkmann <daniel@iogearbox.net>,
Andrii Nakryiko <andrii@kernel.org>,
Masami Hiramatsu <mhiramat@kernel.org>,
Networking <netdev@vger.kernel.org>, bpf <bpf@vger.kernel.org>,
lkml <linux-kernel@vger.kernel.org>,
Martin KaFai Lau <kafai@fb.com>, Song Liu <songliubraving@fb.com>,
Yonghong Song <yhs@fb.com>,
John Fastabend <john.fastabend@gmail.com>,
KP Singh <kpsingh@chromium.org>,
Steven Rostedt <rostedt@goodmis.org>
Subject: Re: [PATCH 02/10] bpf: Add multi kprobe link
Date: Sun, 6 Mar 2022 18:28:47 +0100 [thread overview]
Message-ID: <YiTvT0nyWLDvFya+@krava> (raw)
In-Reply-To: <CAEf4BzadsmOTas7BdF-J+de7AqsoccY1o6e0pUBkRuWH+53DiQ@mail.gmail.com>
On Fri, Mar 04, 2022 at 03:11:01PM -0800, Andrii Nakryiko wrote:
SNIP
> > +static int
> > +kprobe_multi_resolve_syms(const void *usyms, u32 cnt,
> > + unsigned long *addrs)
> > +{
> > + unsigned long addr, size;
> > + const char **syms;
> > + int err = -ENOMEM;
> > + unsigned int i;
> > + char *func;
> > +
> > + size = cnt * sizeof(*syms);
> > + syms = kvzalloc(size, GFP_KERNEL);
> > + if (!syms)
> > + return -ENOMEM;
> > +
> > + func = kmalloc(KSYM_NAME_LEN, GFP_KERNEL);
> > + if (!func)
> > + goto error;
> > +
> > + if (copy_from_user(syms, usyms, size)) {
> > + err = -EFAULT;
> > + goto error;
> > + }
> > +
> > + for (i = 0; i < cnt; i++) {
> > + err = strncpy_from_user(func, syms[i], KSYM_NAME_LEN);
> > + if (err == KSYM_NAME_LEN)
> > + err = -E2BIG;
> > + if (err < 0)
> > + goto error;
> > +
> > + err = -EINVAL;
> > + if (func[0] == '\0')
> > + goto error;
>
> wouldn't empty string be handled by kallsyms_lookup_name?
it would scan and compare all symbols with empty string,
so it's better to test for it
jirka
>
> > + addr = kallsyms_lookup_name(func);
> > + if (!addr)
> > + goto error;
> > + if (!kallsyms_lookup_size_offset(addr, &size, NULL))
> > + size = MCOUNT_INSN_SIZE;
> > + addr = ftrace_location_range(addr, addr + size - 1);
> > + if (!addr)
> > + goto error;
> > + addrs[i] = addr;
> > + }
> > +
> > + err = 0;
> > +error:
> > + kvfree(syms);
> > + kfree(func);
> > + return err;
> > +}
> > +
>
> [...]
next prev parent reply other threads:[~2022-03-06 17:28 UTC|newest]
Thread overview: 39+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-02-22 17:05 [PATCHv2 bpf-next 0/8] bpf: Add kprobe multi link Jiri Olsa
2022-02-22 17:05 ` [PATCH 01/10] lib/sort: Add priv pointer to swap function Jiri Olsa
2022-02-23 3:22 ` Masami Hiramatsu
2022-02-22 17:05 ` [PATCH 02/10] bpf: Add multi kprobe link Jiri Olsa
2022-02-23 5:58 ` Masami Hiramatsu
2022-02-23 17:44 ` Jiri Olsa
2022-02-24 4:02 ` Masami Hiramatsu
2022-03-04 23:11 ` Andrii Nakryiko
2022-03-06 17:28 ` Jiri Olsa [this message]
2022-03-08 1:23 ` Andrii Nakryiko
2022-03-08 14:21 ` Jiri Olsa
2022-02-22 17:05 ` [PATCH 03/10] bpf: Add bpf_get_func_ip kprobe helper for " Jiri Olsa
2022-03-04 23:11 ` Andrii Nakryiko
2022-02-22 17:05 ` [PATCH 04/10] bpf: Add support to inline bpf_get_func_ip helper on x86 Jiri Olsa
2022-02-22 17:05 ` [PATCH 05/10] bpf: Add cookie support to programs attached with kprobe multi link Jiri Olsa
2022-03-04 23:11 ` Andrii Nakryiko
2022-03-06 17:29 ` Jiri Olsa
2022-03-08 1:23 ` Andrii Nakryiko
2022-03-08 14:27 ` Jiri Olsa
2022-02-22 17:05 ` [PATCH 06/10] libbpf: Add libbpf_kallsyms_parse function Jiri Olsa
2022-03-04 23:11 ` Andrii Nakryiko
2022-02-22 17:05 ` [PATCH 07/10] libbpf: Add bpf_link_create support for multi kprobes Jiri Olsa
2022-03-04 23:11 ` Andrii Nakryiko
2022-03-06 17:29 ` Jiri Olsa
2022-02-22 17:05 ` [PATCH 08/10] libbpf: Add bpf_program__attach_kprobe_opts " Jiri Olsa
2022-03-04 23:11 ` Andrii Nakryiko
2022-03-06 17:29 ` Jiri Olsa
2022-03-08 1:28 ` Andrii Nakryiko
2022-03-08 14:23 ` Jiri Olsa
2022-02-22 17:05 ` [PATCH 09/10] selftest/bpf: Add kprobe_multi attach test Jiri Olsa
2022-03-04 23:11 ` Andrii Nakryiko
2022-03-06 17:29 ` Jiri Olsa
2022-02-22 17:06 ` [PATCH 10/10] selftest/bpf: Add kprobe_multi test for bpf_cookie values Jiri Olsa
2022-03-04 23:11 ` Andrii Nakryiko
2022-03-06 17:29 ` Jiri Olsa
2022-03-04 23:10 ` [PATCHv2 bpf-next 0/8] bpf: Add kprobe multi link Andrii Nakryiko
2022-03-06 1:09 ` Steven Rostedt
2022-03-06 1:32 ` Masami Hiramatsu
2022-03-08 1:45 ` Andrii Nakryiko
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=YiTvT0nyWLDvFya+@krava \
--to=olsajiri@gmail.com \
--cc=andrii.nakryiko@gmail.com \
--cc=andrii@kernel.org \
--cc=ast@kernel.org \
--cc=bpf@vger.kernel.org \
--cc=daniel@iogearbox.net \
--cc=john.fastabend@gmail.com \
--cc=jolsa@kernel.org \
--cc=kafai@fb.com \
--cc=kpsingh@chromium.org \
--cc=linux-kernel@vger.kernel.org \
--cc=mhiramat@kernel.org \
--cc=netdev@vger.kernel.org \
--cc=rostedt@goodmis.org \
--cc=songliubraving@fb.com \
--cc=yhs@fb.com \
/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).