From nobody Thu Apr 2 20:15:16 2026 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id E44C6191F84 for ; Thu, 12 Feb 2026 12:50:20 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.129.124 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1770900622; cv=none; b=bztgUnn07KFUlI6OUJii76oqpbDjR5ygOBubnUb+KbVImNDebQh9qAYauxyNQidoq4lHENYbkXkK+MgRMfgECvFtvqIfIcDpsSCC2nOkSChFrs7mXq9RDM4j35RDirz4Psy90DLNXitdpR1llZ3SO9puyjer358Xo5d1DAxX47Q= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1770900622; c=relaxed/simple; bh=KBukMFqHgWtbWUQ4Qdahgi5wHf/wDKbpF+EZPH1NpJE=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=kDwfPEXXwX+vyjEAYok3p1wgPQ9c+K6PO0894ipw+dpoN7Tq4BXBvjNs4O/3niV4Bq4wJiPnYNnrMMtJ3ckKABEYH0/B/cvkdv1AELBDSwBKlp4qvhBWCwDAuwDVGhnuxNFA3O0a8TgBV6ilM/BTADUoRxq/29xbt08bPao6nkQ= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com; spf=pass smtp.mailfrom=redhat.com; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b=SRd79G+A; arc=none smtp.client-ip=170.10.129.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=redhat.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="SRd79G+A" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1770900620; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=sGcCgAZHk66I41sdH+V/InTAwrTE9rISL0Ovf7HhMvA=; b=SRd79G+Alrfr8H4gSlwWeQBXtulTf0rxML2GyrMvvRNAeY62e8caCHRKRTrx5luCdMNqVp 8wlmxZrpeU+7+vuV+0KcKis36sfb8/0ZF2S8WnuIxABEzJh1RQClZrPKNNUN6YdfAKlxSZ 1dU+IfehLZK/340mCDkCnLrD7jtwCrg= Received: from mx-prod-mc-06.mail-002.prod.us-west-2.aws.redhat.com (ec2-35-165-154-97.us-west-2.compute.amazonaws.com [35.165.154.97]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-663-6JYgwUA6O2Kf_Ktz0zIqKQ-1; Thu, 12 Feb 2026 07:50:17 -0500 X-MC-Unique: 6JYgwUA6O2Kf_Ktz0zIqKQ-1 X-Mimecast-MFC-AGG-ID: 6JYgwUA6O2Kf_Ktz0zIqKQ_1770900614 Received: from mx-prod-int-01.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-01.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.4]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mx-prod-mc-06.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 3209918003F6; Thu, 12 Feb 2026 12:50:14 +0000 (UTC) Received: from fedora.redhat.com (unknown [10.44.22.11]) by mx-prod-int-01.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 4102130001B9; Thu, 12 Feb 2026 12:50:08 +0000 (UTC) From: Gabriele Paoloni To: corbet@lwn.net, skhan@linuxfoundation.org, arnd@arndb.de, gregkh@linuxfoundation.org, brendan.higgins@linux.dev, raemoar63@gmail.com, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org, kunit-dev@googlegroups.com Cc: acarminati@nvidia.com, linux-mm@kvack.org, safety-architecture@lists.elisa.tech, kstewart@linuxfoundation.org, chuckwolber@gmail.com, gpaoloni@redhat.com, Alessandro Carminati Subject: [RFC PATCH v3 6/6] char: mem: add Kconfig option for devmem KUnit tests Date: Thu, 12 Feb 2026 13:49:23 +0100 Message-ID: <20260212124923.222484-7-gpaoloni@redhat.com> In-Reply-To: <20260212124923.222484-1-gpaoloni@redhat.com> References: <20260212124923.222484-1-gpaoloni@redhat.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-Scanned-By: MIMEDefang 3.4.1 on 10.30.177.4 Content-Type: text/plain; charset="utf-8" From: Alessandro Carminati Introduce a dedicated Kconfig option to enable extended KUnit testing for /dev/mem behavior. The option enables tests covering I/O memory access restrictions, including behavior under CONFIG_IO_STRICT_DEVMEM. Because the tests may perform reads from I/O regions, they are opt-in and documented with appropriate warnings. This keeps test coverage explicit and avoids unintended hardware side effects. Signed-off-by: Alessandro Carminati --- drivers/char/Kconfig | 21 +++++++++++++++++++++ drivers/char/Makefile | 1 + 2 files changed, 22 insertions(+) diff --git a/drivers/char/Kconfig b/drivers/char/Kconfig index d2cfc584e202..cd3e47b47f44 100644 --- a/drivers/char/Kconfig +++ b/drivers/char/Kconfig @@ -317,6 +317,27 @@ config DEVMEM memory. When in doubt, say "Y". =20 +config DEVMEM_KUNIT_TEST + tristate "KUnit tests for /dev/mem" if !KUNIT_ALL_TESTS + depends on KUNIT + default KUNIT_ALL_TESTS + help + Enables in-kernel unit tests for /dev/mem read/write logic. + +config DEVMEM_KUNIT_TEST_IO + bool "KUnit tests for /dev/mem extended to I/O space" + depends on DEVMEM_KUNIT_TEST + default n + help + Extend KUnit tests for devmem to cover IO space. + When CONFIG_IO_STRICT_DEVMEM is enabled, the kernel denies + access to claimed IO regions. Enabling this option adds two + KUnit test cases to verify this behavior. + Note: These tests perform read operations, which can have + side effects on certain hardware. + Enable this only if you are certain your hardware handles + unsolicited reads safely. + config NVRAM tristate "/dev/nvram support" depends on X86 || HAVE_ARCH_NVRAM_OPS diff --git a/drivers/char/Makefile b/drivers/char/Makefile index 1291369b9126..176f2b8f98dc 100644 --- a/drivers/char/Makefile +++ b/drivers/char/Makefile @@ -4,6 +4,7 @@ # =20 obj-y +=3D mem.o random.o +obj-$(CONFIG_DEVMEM_KUNIT_TEST) +=3D mem_kunit_test.o obj-$(CONFIG_TTY_PRINTK) +=3D ttyprintk.o obj-y +=3D misc.o obj-$(CONFIG_TEST_MISC_MINOR) +=3D misc_minor_kunit.o --=20 2.48.1