Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit ef1d7151 authored by Akinobu Mita's avatar Akinobu Mita Committed by Linus Torvalds
Browse files

cpu hotplug: intel_cacheinfo: fix cpu hotplug error handling 



- Fix resource leakage in error case within detect_cache_attributes()

- Don't register hotcpu notifier when cache_add_dev() returns error

- Introduce cache_dev_map cpumask to track whether cache interface for
  CPU is successfully added by cache_add_dev() or not.

  cache_add_dev() may fail with out of memory error. In order to
  avoid cache_remove_dev() with that uninitialized cache interface when
  CPU_DEAD event is delivered we need to have the cache_dev_map cpumask.

  (We cannot change cache_add_dev() from CPU_ONLINE event handler
  to CPU_UP_PREPARE event handler. Because cache_add_dev() needs
  to do cpuid and store the results with its CPU online.)

[nix.or.die@googlemail.com: fix a section mismatch warning]
Cc: Ashok Raj <ashok.raj@intel.com>
Signed-off-by: default avatarAkinobu Mita <akinobu.mita@gmail.com>
Cc: Gautham R Shenoy <ego@in.ibm.com>
Cc: Oleg Nesterov <oleg@tv-sign.ru>
Cc: Andi Kleen <ak@suse.de>
Cc: Jan Beulich <jbeulich@novell.com>
Signed-off-by: default avatarGabriel Craciunescu <nix.or.die@googlemail.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent d435d862

arch/x86/kernel/cpu/intel_cacheinfo.c

+45 −21
Original line number Diff line number Diff line
@@ -499,6 +499,11 @@ static void __cpuinit cache_remove_shared_cpu_map(unsigned int cpu, int index) { 


static void free_cache_attributes(unsigned int cpu)

{

	int i;



	for (i = 0; i < num_cache_leaves; i++)

		cache_remove_shared_cpu_map(cpu, i);



	kfree(cpuid4_info[cpu]);

	cpuid4_info[cpu] = NULL;

}
@@ -524,19 +529,26 @@ static int __cpuinit detect_cache_attributes(unsigned int cpu) 
		goto out;



	/* Do cpuid and store the results */

	retval = 0;

	for (j = 0; j < num_cache_leaves; j++) {

		this_leaf = CPUID4_INFO_IDX(cpu, j);

		retval = cpuid4_cache_lookup(j, this_leaf);

		if (unlikely(retval < 0))

		if (unlikely(retval < 0)) {

			int i;



			for (i = 0; i < j; i++)

				cache_remove_shared_cpu_map(cpu, i);

			break;

		}

		cache_shared_cpu_map_setup(cpu, j);

	}

	set_cpus_allowed(current, oldmask);



out:

	if (retval)

		free_cache_attributes(cpu);

	if (retval) {

		kfree(cpuid4_info[cpu]);

		cpuid4_info[cpu] = NULL;

	}



	return retval;

}
@@ -669,7 +681,7 @@ static struct kobj_type ktype_percpu_entry = { 
	.sysfs_ops	= &sysfs_ops,

};



static void cpuid4_cache_sysfs_exit(unsigned int cpu)

static void __cpuinit cpuid4_cache_sysfs_exit(unsigned int cpu)

{

	kfree(cache_kobject[cpu]);

	kfree(index_kobject[cpu]);
@@ -680,13 +692,14 @@ static void cpuid4_cache_sysfs_exit(unsigned int cpu) 


static int __cpuinit cpuid4_cache_sysfs_init(unsigned int cpu)

{

	int err;



	if (num_cache_leaves == 0)

		return -ENOENT;



	detect_cache_attributes(cpu);

	if (cpuid4_info[cpu] == NULL)

		return -ENOENT;

	err = detect_cache_attributes(cpu);

	if (err)

		return err;



	/* Allocate all required memory */

	cache_kobject[cpu] = kzalloc(sizeof(struct kobject), GFP_KERNEL);
@@ -705,13 +718,15 @@ err_out: 
	return -ENOMEM;

}



static cpumask_t cache_dev_map = CPU_MASK_NONE;



/* Add/Remove cache interface for CPU device */

static int __cpuinit cache_add_dev(struct sys_device * sys_dev)

{

	unsigned int cpu = sys_dev->id;

	unsigned long i, j;

	struct _index_kobject *this_object;

	int retval = 0;

	int retval;



	retval = cpuid4_cache_sysfs_init(cpu);

	if (unlikely(retval < 0))
@@ -721,6 +736,10 @@ static int __cpuinit cache_add_dev(struct sys_device * sys_dev) 
	kobject_set_name(cache_kobject[cpu], "%s", "cache");

	cache_kobject[cpu]->ktype = &ktype_percpu_entry;

	retval = kobject_register(cache_kobject[cpu]);

	if (retval < 0) {

		cpuid4_cache_sysfs_exit(cpu);

		return retval;

	}



	for (i = 0; i < num_cache_leaves; i++) {

		this_object = INDEX_KOBJECT_PTR(cpu,i);
@@ -740,6 +759,9 @@ static int __cpuinit cache_add_dev(struct sys_device * sys_dev) 
			break;

		}

	}

	if (!retval)

		cpu_set(cpu, cache_dev_map);



	return retval;

}
@@ -750,13 +772,14 @@ static void __cpuinit cache_remove_dev(struct sys_device * sys_dev) 


	if (cpuid4_info[cpu] == NULL)

		return;

	for (i = 0; i < num_cache_leaves; i++) {

		cache_remove_shared_cpu_map(cpu, i);

	if (!cpu_isset(cpu, cache_dev_map))

		return;

	cpu_clear(cpu, cache_dev_map);



	for (i = 0; i < num_cache_leaves; i++)

		kobject_unregister(&(INDEX_KOBJECT_PTR(cpu,i)->kobj));

	}

	kobject_unregister(cache_kobject[cpu]);

	cpuid4_cache_sysfs_exit(cpu);

	return;

}



static int __cpuinit cacheinfo_cpu_callback(struct notifier_block *nfb,
@@ -791,14 +814,15 @@ static int __cpuinit cache_sysfs_init(void) 
	if (num_cache_leaves == 0)

		return 0;



	register_hotcpu_notifier(&cacheinfo_cpu_notifier);



	for_each_online_cpu(i) {

		struct sys_device *sys_dev = get_cpu_sysdev((unsigned int)i);

		int err;

		struct sys_device *sys_dev = get_cpu_sysdev(i);



		cache_add_dev(sys_dev);

		err = cache_add_dev(sys_dev);

		if (err)

			return err;

	}



	register_hotcpu_notifier(&cacheinfo_cpu_notifier);

	return 0;

}