50a9ff6df4
The kernel is moved ahead to version 3.10.0-693.21.1.el7 To summarize: CVE-2017-5753 [bounds check bypass] aka 'Spectre Variant 1' This is fixed by load fences and is "baked in" and cannot be turned off. CVE-2017-5715 [branch target injection] aka 'Spectre Variant 2' This is fixed by a combination of retpolines and IBPB, or IBRS+IBPB if on skylake. This requires a microcode change in the processors. This feature, if on, has a significant performance impact. It is assumed on unless turned off via the "nospectre_v2" bootarg. CVE-2017-5754 [rogue data cache load] aka 'Meltdown' aka 'Variant 3' This is fixed by page table isolation using the Kaiser patches. This feature is assumed on unless turned off via the "nopti" bootarg. As of the commit date, we have changed the installer kickstarts to issue both "nopti nospectre_v2" bootargs to minimize realtime impacts by default. The customer will be able to optionally sacrifice performance for extra security at datafill time. Change-Id: Id7c99923f2ee2ee91f77c7bd9940e684eff8b476 Signed-off-by: Jim Somerville <Jim.Somerville@windriver.com>
93 lines
3.6 KiB
Diff
93 lines
3.6 KiB
Diff
From 52a9e3d1424fb24f3a5683919fc8a1d98d10e869 Mon Sep 17 00:00:00 2001
|
|
Message-Id: <52a9e3d1424fb24f3a5683919fc8a1d98d10e869.1522795098.git.Jim.Somerville@windriver.com>
|
|
In-Reply-To: <21c11de06542297206c798b405b54a3ec9052aa4.1522795097.git.Jim.Somerville@windriver.com>
|
|
References: <21c11de06542297206c798b405b54a3ec9052aa4.1522795097.git.Jim.Somerville@windriver.com>
|
|
From: "Rafael J. Wysocki" <rafael.j.wysocki@intel.com>
|
|
Date: Fri, 24 Feb 2017 13:25:14 +0100
|
|
Subject: [PATCH 25/33] cpuidle: menu: Avoid taking spinlock for accessing QoS
|
|
values
|
|
|
|
[commit 6dbf5cea05a7098a69f294c96b6d76f08562cae5 from linux-stable ]
|
|
|
|
After commit 9908859acaa9 (cpuidle/menu: add per CPU PM QoS resume
|
|
latency consideration) the cpuidle menu governor calls
|
|
dev_pm_qos_read_value() on CPU devices to read the current resume latency QoS
|
|
constraint values for them. That function takes a spinlock to prevent the
|
|
device's power.qos pointer from becoming NULL during the access which is a
|
|
problem for the RT patchset where spinlocks are converted into mutexes and
|
|
the idle loop stops working.
|
|
|
|
However, it is not even necessary for the menu governor to take
|
|
that spinlock, because the power.qos pointer accessed under it
|
|
cannot be modified during the access anyway.
|
|
|
|
For this reason, introduce a "raw" routine for accessing device
|
|
QoS resume latency constraints without locking and use it in the
|
|
menu governor.
|
|
|
|
Fixes: 9908859acaa9 (cpuidle/menu: add per CPU PM QoS resume latency consideration)
|
|
Acked-by: Alex Shi <alex.shi@linaro.org>
|
|
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
|
|
Signed-off-by: Alex Kozyrev <alex.kozyrev@windriver.com>
|
|
Signed-off-by: Jim Somerville <Jim.Somerville@windriver.com>
|
|
---
|
|
drivers/base/power/qos.c | 3 +--
|
|
drivers/cpuidle/governors/menu.c | 2 +-
|
|
include/linux/pm_qos.h | 6 ++++++
|
|
3 files changed, 8 insertions(+), 3 deletions(-)
|
|
|
|
diff --git a/drivers/base/power/qos.c b/drivers/base/power/qos.c
|
|
index 2f8ac59..08a4cec 100644
|
|
--- a/drivers/base/power/qos.c
|
|
+++ b/drivers/base/power/qos.c
|
|
@@ -104,8 +104,7 @@ EXPORT_SYMBOL_GPL(dev_pm_qos_flags);
|
|
*/
|
|
s32 __dev_pm_qos_read_value(struct device *dev)
|
|
{
|
|
- return IS_ERR_OR_NULL(dev->power.qos) ?
|
|
- 0 : pm_qos_read_value(&dev->power.qos->latency);
|
|
+ return dev_pm_qos_raw_read_value(dev);
|
|
}
|
|
|
|
/**
|
|
diff --git a/drivers/cpuidle/governors/menu.c b/drivers/cpuidle/governors/menu.c
|
|
index fe2dcb8..f9861fd 100644
|
|
--- a/drivers/cpuidle/governors/menu.c
|
|
+++ b/drivers/cpuidle/governors/menu.c
|
|
@@ -265,7 +265,7 @@ static int menu_select(struct cpuidle_driver *drv, struct cpuidle_device *dev)
|
|
int i;
|
|
int multiplier;
|
|
struct timespec t;
|
|
- int resume_latency = dev_pm_qos_read_value(device);
|
|
+ int resume_latency = dev_pm_qos_raw_read_value(device);
|
|
|
|
if (data->needs_update) {
|
|
menu_update(drv, dev);
|
|
diff --git a/include/linux/pm_qos.h b/include/linux/pm_qos.h
|
|
index 5281e7f..1d8b629 100644
|
|
--- a/include/linux/pm_qos.h
|
|
+++ b/include/linux/pm_qos.h
|
|
@@ -217,6 +217,11 @@ static inline s32 dev_pm_qos_requested_flags(struct device *dev)
|
|
{
|
|
return dev->power.qos->flags_req->data.flr.flags;
|
|
}
|
|
+static inline s32 dev_pm_qos_raw_read_value(struct device *dev)
|
|
+{
|
|
+ return IS_ERR_OR_NULL(dev->power.qos) ?
|
|
+ 0 : pm_qos_read_value(&dev->power.qos->latency);
|
|
+}
|
|
#else
|
|
static inline int dev_pm_qos_expose_latency_limit(struct device *dev, s32 value)
|
|
{ return 0; }
|
|
@@ -236,6 +241,7 @@ static inline void dev_pm_qos_hide_latency_tolerance(struct device *dev) {}
|
|
|
|
static inline s32 dev_pm_qos_requested_latency(struct device *dev) { return 0; }
|
|
static inline s32 dev_pm_qos_requested_flags(struct device *dev) { return 0; }
|
|
+static inline s32 dev_pm_qos_raw_read_value(struct device *dev) { return 0; }
|
|
#endif
|
|
|
|
#endif
|
|
--
|
|
1.8.3.1
|
|
|