public inbox for linux-kernel@vger.kernel.org
 help / color / mirror / Atom feed
From: Simon Horman <horms@kernel.org>
To: Andrew Morton <akpm@linux-foundation.org>
Cc: Eric Biederman <ebiederm@xmission.com>,
	Baoquan He <bhe@redhat.com>,
	"Leizhen (ThunderTown)" <thunder.leizhen@huawei.com>,
	kexec@lists.infradead.org, linux-kernel@vger.kernel.org
Subject: [PATCH] kexec: Avoid calculating array size twice
Date: Thu, 25 May 2023 16:26:25 +0200	[thread overview]
Message-ID: <20230525-kexec-array_size-v1-1-8b4bf4f7500a@kernel.org> (raw)

Avoid calculating array size twice in kexec_purgatory_setup_sechdrs().
Once using array_size(), and once open-coded.

Flagged by Coccinelle:

  .../kexec_file.c:881:8-25: WARNING: array_size is already used (line 877) to compute the same size

No functional change intended.
Compile tested only.

Signed-off-by: Simon Horman <horms@kernel.org>
---
 kernel/kexec_file.c | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/kernel/kexec_file.c b/kernel/kexec_file.c
index f989f5f1933b..3f5677679744 100644
--- a/kernel/kexec_file.c
+++ b/kernel/kexec_file.c
@@ -867,6 +867,7 @@ static int kexec_purgatory_setup_sechdrs(struct purgatory_info *pi,
 {
 	unsigned long bss_addr;
 	unsigned long offset;
+	size_t sechdrs_size;
 	Elf_Shdr *sechdrs;
 	int i;
 
@@ -874,11 +875,11 @@ static int kexec_purgatory_setup_sechdrs(struct purgatory_info *pi,
 	 * The section headers in kexec_purgatory are read-only. In order to
 	 * have them modifiable make a temporary copy.
 	 */
-	sechdrs = vzalloc(array_size(sizeof(Elf_Shdr), pi->ehdr->e_shnum));
+	sechdrs_size = array_size(sizeof(Elf_Shdr), pi->ehdr->e_shnum);
+	sechdrs = vzalloc(sechdrs_size);
 	if (!sechdrs)
 		return -ENOMEM;
-	memcpy(sechdrs, (void *)pi->ehdr + pi->ehdr->e_shoff,
-	       pi->ehdr->e_shnum * sizeof(Elf_Shdr));
+	memcpy(sechdrs, (void *)pi->ehdr + pi->ehdr->e_shoff, sechdrs_size);
 	pi->sechdrs = sechdrs;
 
 	offset = 0;


             reply	other threads:[~2023-05-25 14:26 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-05-25 14:26 Simon Horman [this message]
2023-06-01 10:40 ` [PATCH] kexec: Avoid calculating array size twice Baoquan He
2023-06-01 10:49   ` Baoquan He

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=20230525-kexec-array_size-v1-1-8b4bf4f7500a@kernel.org \
    --to=horms@kernel.org \
    --cc=akpm@linux-foundation.org \
    --cc=bhe@redhat.com \
    --cc=ebiederm@xmission.com \
    --cc=kexec@lists.infradead.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=thunder.leizhen@huawei.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