From: Jiri Olsa <jolsa@kernel.org>
To: Alexei Starovoitov <ast@kernel.org>,
Daniel Borkmann <daniel@iogearbox.net>,
Andrii Nakryiko <andrii@kernel.org>,
Masami Hiramatsu <mhiramat@kernel.org>
Cc: netdev@vger.kernel.org, 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: [PATCHv3 bpf-next 02/13] kallsyms: Skip the name search for empty string
Date: Wed, 16 Mar 2022 13:24:08 +0100 [thread overview]
Message-ID: <20220316122419.933957-3-jolsa@kernel.org> (raw)
In-Reply-To: <20220316122419.933957-1-jolsa@kernel.org>
When kallsyms_lookup_name is called with empty string,
it will do futile search for it through all the symbols.
Skipping the search for empty string.
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
---
kernel/kallsyms.c | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/kernel/kallsyms.c b/kernel/kallsyms.c
index 951c93216fc4..79f2eb617a62 100644
--- a/kernel/kallsyms.c
+++ b/kernel/kallsyms.c
@@ -212,6 +212,10 @@ unsigned long kallsyms_lookup_name(const char *name)
unsigned long i;
unsigned int off;
+ /* Skip the search for empty string. */
+ if (!*name)
+ return 0;
+
for (i = 0, off = 0; i < kallsyms_num_syms; i++) {
off = kallsyms_expand_symbol(off, namebuf, ARRAY_SIZE(namebuf));
--
2.35.1
next prev parent reply other threads:[~2022-03-16 12:24 UTC|newest]
Thread overview: 26+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-03-16 12:24 [PATCHv3 bpf-next 00/13] bpf: Add kprobe multi link Jiri Olsa
2022-03-16 12:24 ` [PATCHv3 bpf-next 01/13] lib/sort: Add priv pointer to swap function Jiri Olsa
2022-03-16 12:24 ` Jiri Olsa [this message]
2022-03-16 12:24 ` [PATCHv3 bpf-next 03/13] bpf: Add multi kprobe link Jiri Olsa
2022-03-16 18:53 ` Alexei Starovoitov
2022-03-17 13:24 ` Jiri Olsa
2022-03-16 12:24 ` [PATCHv3 bpf-next 04/13] bpf: Add bpf_get_func_ip kprobe helper for " Jiri Olsa
2022-03-16 12:24 ` [PATCHv3 bpf-next 05/13] bpf: Add support to inline bpf_get_func_ip helper on x86 Jiri Olsa
2022-03-16 12:24 ` [PATCHv3 bpf-next 06/13] bpf: Add cookie support to programs attached with kprobe multi link Jiri Olsa
2022-03-16 12:24 ` [PATCHv3 bpf-next 07/13] libbpf: Add libbpf_kallsyms_parse function Jiri Olsa
2022-03-16 12:24 ` [PATCHv3 bpf-next 08/13] libbpf: Add bpf_link_create support for multi kprobes Jiri Olsa
2022-03-16 12:24 ` [PATCHv3 bpf-next 09/13] libbpf: Add bpf_program__attach_kprobe_multi_opts function Jiri Olsa
2022-03-18 3:53 ` Alexei Starovoitov
2022-03-18 5:14 ` Andrii Nakryiko
2022-03-18 9:22 ` Jiri Olsa
2022-03-18 9:08 ` Jiri Olsa
2022-03-16 12:24 ` [PATCHv3 bpf-next 10/13] selftests/bpf: Add kprobe_multi attach test Jiri Olsa
2022-03-16 12:24 ` [PATCHv3 bpf-next 11/13] selftests/bpf: Add kprobe_multi bpf_cookie test Jiri Olsa
2022-03-16 12:24 ` [PATCHv3 bpf-next 12/13] selftests/bpf: Add attach test for bpf_program__attach_kprobe_multi_opts Jiri Olsa
2022-03-16 12:24 ` [PATCHv3 bpf-next 13/13] selftests/bpf: Add cookie " Jiri Olsa
2022-03-18 3:50 ` [PATCHv3 bpf-next 00/13] bpf: Add kprobe multi link patchwork-bot+netdevbpf
2022-03-19 5:50 ` Andrii Nakryiko
2022-03-19 12:27 ` Jiri Olsa
2022-03-19 14:31 ` Jiri Olsa
2022-03-19 18:26 ` Andrii Nakryiko
2022-03-19 19:01 ` Andrii Nakryiko
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