The patch titled
Subject: kexec: avoid calculating array size twice
has been added to the -mm mm-nonmm-unstable branch. Its filename is
kexec-avoid-calculating-array-size-twice.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/kexec-avoid-calculating-array-size-twice.patch
This patch will later appear in the mm-nonmm-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
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From: Simon Horman <horms@xxxxxxxxxx>
Subject: kexec: avoid calculating array size twice
Date: Thu, 25 May 2023 16:26:25 +0200
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.
Link: https://lkml.kernel.org/r/20230525-kexec-array_size-v1-1-8b4bf4f7500a@xxxxxxxxxx
Signed-off-by: Simon Horman <horms@xxxxxxxxxx>
Cc: Baoquan He <bhe@xxxxxxxxxx>
Cc: Eric W. Biederman <ebiederm@xxxxxxxxxxxx>
Cc: Zhen Lei <thunder.leizhen@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
kernel/kexec_file.c | 7 ++++---
1 file changed, 4 insertions(+), 3 deletions(-)
--- a/kernel/kexec_file.c~kexec-avoid-calculating-array-size-twice
+++ a/kernel/kexec_file.c
@@ -867,6 +867,7 @@ static int kexec_purgatory_setup_sechdrs
{
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
* 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;
_
Patches currently in -mm which might be from horms@xxxxxxxxxx are
kexec-avoid-calculating-array-size-twice.patch
