[PATCH 2/4] hotplug, x86: Add hotplug lock to missing places
From: Toshi Kani <hidden>
Date: 2013-08-17 19:49:00
Also in:
lkml
Subsystem:
driver core, kobjects, debugfs and sysfs, the rest, x86 architecture (32-bit and 64-bit) · Maintainers:
Greg Kroah-Hartman, "Rafael J. Wysocki", Danilo Krummrich, Linus Torvalds, Thomas Gleixner, Ingo Molnar, Borislav Petkov, Dave Hansen
lock_device_hotplug() serializes CPU & Memory online/offline and hotplug operations. However, this lock is not held in the debug interfaces below that initiate CPU online/offline operations. - _debug_hotplug_cpu(), cpu0 hotplug test interface enabled by CONFIG_DEBUG_HOTPLUG_CPU0. - cpu_probe_store() and cpu_release_store(), cpu hotplug test interface enabled by CONFIG_ARCH_CPU_PROBE_RELEASE. This patch changes the above interfaces to hold lock_device_hotplug(). Signed-off-by: Toshi Kani <redacted> --- arch/x86/kernel/topology.c | 2 ++ drivers/base/cpu.c | 16 ++++++++++++++-- 2 files changed, 16 insertions(+), 2 deletions(-)
diff --git a/arch/x86/kernel/topology.c b/arch/x86/kernel/topology.c
index 5823bbd..a3f35eb 100644
--- a/arch/x86/kernel/topology.c
+++ b/arch/x86/kernel/topology.c@@ -65,6 +65,7 @@ int __ref _debug_hotplug_cpu(int cpu, int action) if (!cpu_is_hotpluggable(cpu)) return -EINVAL; + lock_device_hotplug(); cpu_hotplug_driver_lock(); switch (action) {
@@ -91,6 +92,7 @@ int __ref _debug_hotplug_cpu(int cpu, int action) } cpu_hotplug_driver_unlock(); + unlock_device_hotplug(); return ret; }
diff --git a/drivers/base/cpu.c b/drivers/base/cpu.c
index 4c358bc..4cc6928 100644
--- a/drivers/base/cpu.c
+++ b/drivers/base/cpu.c@@ -88,7 +88,13 @@ static ssize_t cpu_probe_store(struct device *dev, const char *buf, size_t count) { - return arch_cpu_probe(buf, count); + ssize_t ret; + + lock_device_hotplug(); + ret = arch_cpu_probe(buf, count); + unlock_device_hotplug(); + + return ret; } static ssize_t cpu_release_store(struct device *dev,
@@ -96,7 +102,13 @@ static ssize_t cpu_release_store(struct device *dev, const char *buf, size_t count) { - return arch_cpu_release(buf, count); + ssize_t ret; + + lock_device_hotplug(); + ret = arch_cpu_release(buf, count); + unlock_device_hotplug(); + + return ret; } static DEVICE_ATTR(probe, S_IWUSR, NULL, cpu_probe_store);