linux-kernel - Re: [PATCH] netfs: Fix a KMSAN uninit-value error in netfs_clear

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Message-ID: <557230.1726963607@warthog.procyon.org.uk>
Date: Sun, 22 Sep 2024 01:06:47 +0100
From: David Howells <dhowells@...hat.com>
To: Chang Yu <marcus.yu.56@...il.com>
Cc: dhowells@...hat.com, jlayton@...nel.org, netfs@...ts.linux.dev,
    linux-fsdevel@...r.kernel.org, linux-kernel@...r.kernel.org,
    skhan@...uxfoundation.org
Subject: Re: [PATCH] netfs: Fix a KMSAN uninit-value error in netfs_clear_buffer

Chang Yu <marcus.yu.56@...il.com> wrote:

> -		tail = kmalloc(sizeof(*tail), GFP_NOFS);
> +		tail = kzalloc(sizeof(*tail), GFP_NOFS);

I'm deliberately not doing that because of the performance hit.  That's 31
pointers of which, in many cases, we're only going to use the first couple.
There's a bitmask indicating which pointers need putting and a counter that
indicates how many are used.

David