Netdev List
 help / color / mirror / Atom feed
From: Martin KaFai Lau <kafai@fb.com>
To: <netdev@vger.kernel.org>
Cc: Alexei Starovoitov <ast@fb.com>,
	Daniel Borkmann <daniel@iogearbox.net>, <kernel-team@fb.com>
Subject: [PATCH v2 bpf-next] bpf: btf: Avoid variable length array
Date: Wed, 23 May 2018 11:32:36 -0700	[thread overview]
Message-ID: <20180523183236.519795-1-kafai@fb.com> (raw)

Sparse warning:
kernel/bpf/btf.c:1985:34: warning: Variable length array is used.

This patch directly uses ARRAY_SIZE().

Fixes: f80442a4cd18 ("bpf: btf: Change how section is supported in btf_header")
Signed-off-by: Martin KaFai Lau <kafai@fb.com>
---
 kernel/bpf/btf.c | 11 +++++------
 1 file changed, 5 insertions(+), 6 deletions(-)

diff --git a/kernel/bpf/btf.c b/kernel/bpf/btf.c
index 9cbeabb5aca3..7e90fd13b5b5 100644
--- a/kernel/bpf/btf.c
+++ b/kernel/bpf/btf.c
@@ -1981,8 +1981,7 @@ static int btf_sec_info_cmp(const void *a, const void *b)
 static int btf_check_sec_info(struct btf_verifier_env *env,
 			      u32 btf_data_size)
 {
-	const unsigned int nr_secs = ARRAY_SIZE(btf_sec_info_offset);
-	struct btf_sec_info secs[nr_secs];
+	struct btf_sec_info secs[ARRAY_SIZE(btf_sec_info_offset)];
 	u32 total, expected_total, i;
 	const struct btf_header *hdr;
 	const struct btf *btf;
@@ -1991,17 +1990,17 @@ static int btf_check_sec_info(struct btf_verifier_env *env,
 	hdr = &btf->hdr;
 
 	/* Populate the secs from hdr */
-	for (i = 0; i < nr_secs; i++)
+	for (i = 0; i < ARRAY_SIZE(btf_sec_info_offset); i++)
 		secs[i] = *(struct btf_sec_info *)((void *)hdr +
 						   btf_sec_info_offset[i]);
 
-	sort(secs, nr_secs, sizeof(struct btf_sec_info),
-	     btf_sec_info_cmp, NULL);
+	sort(secs, ARRAY_SIZE(btf_sec_info_offset),
+	     sizeof(struct btf_sec_info), btf_sec_info_cmp, NULL);
 
 	/* Check for gaps and overlap among sections */
 	total = 0;
 	expected_total = btf_data_size - hdr->hdr_len;
-	for (i = 0; i < nr_secs; i++) {
+	for (i = 0; i < ARRAY_SIZE(btf_sec_info_offset); i++) {
 		if (expected_total < secs[i].off) {
 			btf_verifier_log(env, "Invalid section offset");
 			return -EINVAL;
-- 
2.9.5

             reply	other threads:[~2018-05-23 18:32 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-05-23 18:32 Martin KaFai Lau [this message]
2018-05-24  7:35 ` [PATCH v2 bpf-next] bpf: btf: Avoid variable length array Daniel Borkmann

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=20180523183236.519795-1-kafai@fb.com \
    --to=kafai@fb.com \
    --cc=ast@fb.com \
    --cc=daniel@iogearbox.net \
    --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