From: Al Viro <viro@zeniv.linux.org.uk>
To: Mehdi Ben Hadj Khelifa <mehdi.benhadjkhelifa@gmail.com>
Cc: brauner@kernel.org, jack@suse.cz, linux-fsdevel@vger.kernel.org,
linux-kernel@vger.kernel.org, skhan@linuxfoundation.org,
david.hunter.linux@gmail.com,
linux-kernel-mentees@lists.linuxfoundation.org
Subject: Re: [PATCH] init: Use kcalloc() instead of kzalloc()
Date: Thu, 2 Oct 2025 03:36:57 +0100 [thread overview]
Message-ID: <20251002023657.GF39973@ZenIV> (raw)
In-Reply-To: <20250930083542.18915-1-mehdi.benhadjkhelifa@gmail.com>
On Tue, Sep 30, 2025 at 09:35:37AM +0100, Mehdi Ben Hadj Khelifa wrote:
> Replace kzalloc() with kcalloc() in init/initramfs_test.c since the
> calculation inside kzalloc is dynamic and could overflow.
Really? Could you explain how
a) ARRAY_SIZE(local variable) * (CPIO_HDRLEN + PATH_MAX + 3)
could possibly be dynamic and
b) just how large would that array have to be for it to "overflow"?
Incidentally, here the use of kcalloc would be unidiomatic - it's _not_
allocating an array of that many fixed-sized elements. CPIO_HDRLEN +
PATH_MAX + 3 is not an element size - it's an upper bound on the amount
of space we might need for a single element. Chunks of data generated
from array elements are placed into that buffer without any gaps -
it's really an array of bytes, large enough to fit all of them.
next prev parent reply other threads:[~2025-10-02 3:01 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-09-30 8:35 [PATCH] init: Use kcalloc() instead of kzalloc() Mehdi Ben Hadj Khelifa
2025-10-02 2:36 ` Al Viro [this message]
2025-10-03 10:40 ` Mehdi Ben Hadj Khelifa
2025-10-18 17:13 ` Mehdi Ben Hadj Khelifa
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