This is a note to let you know that I've just added the patch titled
ACPI / scan: not cache _SUN value in struct acpi_device_pnp
to the 3.16-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
acpi-scan-not-cache-_sun-value-in-struct-acpi_device_pnp.patch
and it can be found in the queue-3.16 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From a383b68d9fe9864c4d3b86f67ad6488f58136435 Mon Sep 17 00:00:00 2001
From: Yasuaki Ishimatsu <isimatu.yasuaki@xxxxxxxxxxxxxx>
Date: Wed, 3 Sep 2014 13:39:13 +0900
Subject: ACPI / scan: not cache _SUN value in struct acpi_device_pnp
From: Yasuaki Ishimatsu <isimatu.yasuaki@xxxxxxxxxxxxxx>
commit a383b68d9fe9864c4d3b86f67ad6488f58136435 upstream.
The _SUN device indentification object is not guaranteed to return
the same value every time it is executed, so we should not cache its
return value, but rather execute it every time as needed. If it is
cached, an incorrect stale value may be used in some situations.
This issue was exposed by commit 202317a573b2 (ACPI / scan: Add
acpi_device objects for all device nodes in the namespace). Fix it
by avoiding to cache the return value of _SUN.
Fixes: 202317a573b2 (ACPI / scan: Add acpi_device objects for all device nodes in the namespace)
Signed-off-by: Yasuaki Ishimatsu <isimatu.yasuaki@xxxxxxxxxxxxxx>
[ rjw: Changelog ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/acpi/scan.c | 15 ++++++++-------
include/acpi/acpi_bus.h | 1 -
2 files changed, 8 insertions(+), 8 deletions(-)
--- a/drivers/acpi/scan.c
+++ b/drivers/acpi/scan.c
@@ -665,8 +665,14 @@ static ssize_t
acpi_device_sun_show(struct device *dev, struct device_attribute *attr,
char *buf) {
struct acpi_device *acpi_dev = to_acpi_device(dev);
+ acpi_status status;
+ unsigned long long sun;
+
+ status = acpi_evaluate_integer(acpi_dev->handle, "_SUN", NULL, &sun);
+ if (ACPI_FAILURE(status))
+ return -ENODEV;
- return sprintf(buf, "%lu\n", acpi_dev->pnp.sun);
+ return sprintf(buf, "%llu\n", sun);
}
static DEVICE_ATTR(sun, 0444, acpi_device_sun_show, NULL);
@@ -688,7 +694,6 @@ static int acpi_device_setup_files(struc
{
struct acpi_buffer buffer = {ACPI_ALLOCATE_BUFFER, NULL};
acpi_status status;
- unsigned long long sun;
int result = 0;
/*
@@ -729,14 +734,10 @@ static int acpi_device_setup_files(struc
if (dev->pnp.unique_id)
result = device_create_file(&dev->dev, &dev_attr_uid);
- status = acpi_evaluate_integer(dev->handle, "_SUN", NULL, &sun);
- if (ACPI_SUCCESS(status)) {
- dev->pnp.sun = (unsigned long)sun;
+ if (acpi_has_method(dev->handle, "_SUN")) {
result = device_create_file(&dev->dev, &dev_attr_sun);
if (result)
goto end;
- } else {
- dev->pnp.sun = (unsigned long)-1;
}
if (acpi_has_method(dev->handle, "_STA")) {
--- a/include/acpi/acpi_bus.h
+++ b/include/acpi/acpi_bus.h
@@ -246,7 +246,6 @@ struct acpi_device_pnp {
acpi_device_name device_name; /* Driver-determined */
acpi_device_class device_class; /* " */
union acpi_object *str_obj; /* unicode string for _STR method */
- unsigned long sun; /* _SUN */
};
#define acpi_device_bid(d) ((d)->pnp.bus_id)
Patches currently in stable-queue which might be from isimatu.yasuaki@xxxxxxxxxxxxxx are
queue-3.16/acpi-scan-not-cache-_sun-value-in-struct-acpi_device_pnp.patch
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