From mboxrd@z Thu Jan  1 00:00:00 1970
From: Joe Perches <joe@perches.com>
Date: Tue, 16 Jun 2020 18:53:50 +0000
Subject: Re: [PATCH v4 0/3] mm, treewide: Rename kzfree() to kfree_sensitive()
Message-Id: <fe3b9a437be4aeab3bac68f04193cb6daaa5bee4.camel@perches.com>
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References: <20200616015718.7812-1-longman@redhat.com>
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To: Waiman Long <longman@redhat.com>, Andrew Morton <akpm@linux-foundation.org>, David Howells <dhowells@redhat.com>, Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>, James Morris <jmorris@namei.org>, "Serge E. Hallyn" <serge@hallyn.com>, Linus Torvalds <torvalds@linux-foundation.org>, Matthew Wilcox <willy@infradead.org>, David Rientjes <rientjes@google.com>
Cc: "Jason A . Donenfeld" <Jason@zx2c4.com>, Michal Hocko <mhocko@suse.com>, linux-btrfs@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-sctp@vger.kernel.org, target-devel@vger.kernel.org, linux-stm32@st-md-mailman.stormreply.com, devel@driverdev.osuosl.org, linux-cifs@vger.kernel.org, linux-scsi@vger.kernel.org, kasan-dev@googlegroups.com, linux-wpan@vger.kernel.org, Dan Carpenter <dan.carpenter@oracle.com>, linux-pm@vger.kernel.org, ecryptfs@vger.kernel.org, linux-fscrypt@vger.kernel.org, linux-mediatek@lists.infradead.org, linux-amlogic@lists.infradead.org, virtualization@lists.linux-foundation.org, linux-nfs@vger.kernel.org, netdev@vger.kernel.org, linux-wireless@vger.kernel.org, David Sterba <dsterba@suse.cz>, linux-bluetooth@vger.kernel.org, linux-security-module@vger.kernel.org, keyrings@vger.kernel.org, tipc-discussion@lists.sourceforge.net, linux-crypto@vger.kernel.org, Johannes Weiner <hannes@cmpxchg.org>, linux-integrity@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, wireguard@lists.zx2c4.com, linux-ppp@vger.kernel.org

On Mon, 2020-06-15 at 21:57 -0400, Waiman Long wrote:
>  v4:
>   - Break out the memzero_explicit() change as suggested by Dan Carpenter
>     so that it can be backported to stable.
>   - Drop the "crypto: Remove unnecessary memzero_explicit()" patch for
>     now as there can be a bit more discussion on what is best. It will be
>     introduced as a separate patch later on after this one is merged.

To this larger audience and last week without reply:
https://lore.kernel.org/lkml/573b3fbd5927c643920e1364230c296b23e7584d.camel@perches.com/

Are there _any_ fastpath uses of kfree or vfree?

Many patches have been posted recently to fix mispairings
of specific types of alloc and free functions.

To eliminate these mispairings at a runtime cost of four
comparisons, should the kfree/vfree/kvfree/kfree_const
functions be consolidated into a single kfree?

Something like the below:

   void kfree(const void *addr)
   {
   	if (is_kernel_rodata((unsigned long)addr))
   		return;

   	if (is_vmalloc_addr(addr))
   		_vfree(addr);
   	else
   		_kfree(addr);
   }

   #define kvfree		kfree
   #define vfree		kfree
   #define kfree_const	kfree