linux-kernel - [PATCH 6/10] ACPI / scan: Change the meaning of missing .attach() in scan handlers

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]

Date:	Fri, 30 May 2014 04:27:31 +0200
From:	"Rafael J. Wysocki" <rjw@...ysocki.net>
To:	Zhang Rui <rui.zhang@...el.com>
Cc:	linux-acpi@...r.kernel.org, linux-kernel@...r.kernel.org,
	matthew.garrett@...ula.com, mika.westerberg@...ux.intel.com
Subject: [PATCH 6/10] ACPI / scan: Change the meaning of missing .attach() in scan handlers

From: Rafael J. Wysocki <rafael.j.wysocki@...el.com>

Currently, some scan handlers can be compiled out entirely, which
leaves the device objects they normally attach to without a scan
handler.  This isn't a problem as long as we don't have any default
enumeration mechanism that applies to all devices without a scan
handler.  However, if such a default enumeration is added, it still
should not be applied to devices that are normally attached to by
scan handlers, because that may result in creating "physical" device
objects of a wrong type for them.

Since we are going to create platform device objects for all ACPI
device objects with pnp.type.platform_id set by default, clear
pnp.type.platform_id where there is a matching scan handler without
an .attach() callback and otherwise simply treat that scan handler
as though the .attach() callback was present but always returned 0.

This will allow us to compile out scan handler callbacks and leave
the device ID lists used by them so as to prevent creating platform
device objects for the matching ACPI devices.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@...el.com>
---
 drivers/acpi/scan.c |    6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

Index: linux-pm/drivers/acpi/scan.c
===================================================================
--- linux-pm.orig/drivers/acpi/scan.c
+++ linux-pm/drivers/acpi/scan.c
@@ -84,7 +84,7 @@ EXPORT_SYMBOL_GPL(acpi_initialize_hp_con

 int acpi_scan_add_handler(struct acpi_scan_handler *handler)
 {
-	if (!handler || !handler->attach)
+	if (!handler)
 		return -EINVAL;

 	list_add_tail(&handler->list_node, &acpi_scan_handlers_list);
@@ -2081,6 +2081,10 @@ static int acpi_scan_attach_handler(stru

 		handler = acpi_scan_match_handler(hwid->id, &devid);
 		if (handler) {
+			if (!handler->attach) {
+				device->pnp.type.platform_id = 0;
+				continue;
+			}
 			device->handler = handler;
 			ret = handler->attach(device, devid);
 			if (ret > 0)

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/