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Date: Thu, 23 May 2024 18:01:49 +0300
Message-Id: <D1H452IHSLRC.1WZSPJQLCD5RD@kernel.org>
From: "Jarkko Sakkinen" <jarkko@kernel.org>
To: <linux-modules@vger.kernel.org>
Cc: "Luis Chamberlain" <mcgrof@kernel.org>, "Linus Torvalds"
 <torvalds@linux-foundation.org>, <linux-kernel@vger.kernel.org>, "Herbert
 Xu" <herbert@gondor.apana.org.au>, <linux-crypto@vger.kernel.org>
Subject: is_module()

Hi,

I just put this here while I still have it on my mind. Possibly I'm
ignoring something that already enables this but at least I learn
something by doing this then.=20

This came up in a recent discussion albeit for this crypto bug it
did not make waves because the bug fix did not require it:

https://lore.kernel.org/linux-integrity/D1GXKODMD4S8.1J12D4GOEQWPL@kernel.o=
rg/

So the gist of  is_module() would be that it would have different
semantics than IS_MODULE(): it could be used to e.g. check modules in a
loop.

Compilation would generate a new ELF section with following entries:

<ASCIIZ string><0 or 1>

The string would contain module name, and 1 could be marking for
being a module, and 0 for being builtin.

Also, it would enabled to add lsmod -b to enumerate built-in modules,
which would give nice way to carve up more information about a running
test kernel. This would obviously need perhaps a new file to procfs for
built-in modules (for regular there is /proc/modules).

Not fighting for having this, just makig it visible.

BR, Jarkko