linux-kernel - [PATCH 3/3] ACPI: APEI: EINJ: Do not fail einj_init() on faux_device

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20250607033228.1475625-4-dan.j.williams@intel.com>
Date: Fri, 6 Jun 2025 20:32:28 -0700
From: Dan Williams <dan.j.williams@...el.com>
To: <gregkh@...uxfoundation.org>, <rafael.j.wysocki@...el.com>
CC: <linux-cxl@...r.kernel.org>, <linux-acpi@...r.kernel.org>,
	<linux-kernel@...r.kernel.org>, "Rafael J. Wysocki" <rafael@...nel.org>,
	Sudeep Holla <sudeep.holla@....com>, Ben Cheatham <Benjamin.Cheatham@....com>
Subject: [PATCH 3/3] ACPI: APEI: EINJ: Do not fail einj_init() on faux_device_create() failure

CXL has a symbol dependency on einj_core.ko, so if einj_init() fails then
cxl_core.ko fails to load. Prior to the faux_device_create() conversion,
einj_probe() failures were tracked by the einj_initialized flag without
failing einj_init().

Revert to that behavior and always succeed einj_init() given there is no
way, and no pressing need, to discern faux device-create vs device-probe
failures.

This situation arose because CXL knows proper kernel named objects to
trigger errors against, but acpi-einj knows how to perform the error
injection. The injection mechanism is shared with non-CXL use cases. The
result is CXL now has a module dependency on einj-core.ko, and init/probe
failures are handled at runtime.

Fixes: 6cb9441bfe8d ("ACPI: APEI: EINJ: Transition to the faux device interface")
Cc: Greg Kroah-Hartman <gregkh@...uxfoundation.org>
Cc: "Rafael J. Wysocki" <rafael@...nel.org>
Cc: Sudeep Holla <sudeep.holla@....com>
Cc: Ben Cheatham <Benjamin.Cheatham@....com>
Signed-off-by: Dan Williams <dan.j.williams@...el.com>
---
 drivers/acpi/apei/einj-core.c | 9 +++------
 1 file changed, 3 insertions(+), 6 deletions(-)

diff --git a/drivers/acpi/apei/einj-core.c b/drivers/acpi/apei/einj-core.c
index fea11a35eea3..9b041415a9d0 100644
--- a/drivers/acpi/apei/einj-core.c
+++ b/drivers/acpi/apei/einj-core.c
@@ -883,19 +883,16 @@ static int __init einj_init(void)
 	}

 	einj_dev = faux_device_create("acpi-einj", NULL, &einj_device_ops);
-	if (!einj_dev)
-		return -ENODEV;

-	einj_initialized = true;
+	if (einj_dev)
+		einj_initialized = true;

 	return 0;
 }

 static void __exit einj_exit(void)
 {
-	if (einj_initialized)
-		faux_device_destroy(einj_dev);
-
+	faux_device_destroy(einj_dev);
 }

 module_init(einj_init);
-- 
2.49.0