lkml.org 
[lkml]   [2007]   [Jul]   [16]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    Patch in this message
    /
    Date
    From
    Subject[PATCH 10/10] intel_cacheinfo: fix cpu hotplug error handling
    - Fix resource leakage in error case within detect_cache_attributes()

    - 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.)

    Cc: Ashok Raj <ashok.raj@intel.com>
    Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>

    ---
    arch/i386/kernel/cpu/intel_cacheinfo.c | 57 +++++++++++++++++++++++----------
    1 file changed, 40 insertions(+), 17 deletions(-)

    Index: 2.6-mm/arch/i386/kernel/cpu/intel_cacheinfo.c
    ===================================================================
    --- 2.6-mm.orig/arch/i386/kernel/cpu/intel_cacheinfo.c
    +++ 2.6-mm/arch/i386/kernel/cpu/intel_cacheinfo.c
    @@ -502,6 +502,11 @@ static void __init cache_remove_shared_c

    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;
    }
    @@ -509,8 +514,8 @@ static void free_cache_attributes(unsign
    static int __cpuinit detect_cache_attributes(unsigned int cpu)
    {
    struct _cpuid4_info *this_leaf;
    - unsigned long j;
    - int retval;
    + unsigned long j;
    + int retval;
    cpumask_t oldmask;

    if (num_cache_leaves == 0)
    @@ -527,19 +532,26 @@ static int __cpuinit detect_cache_attrib
    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;
    }

    @@ -683,13 +695,14 @@ static void cpuid4_cache_sysfs_exit(unsi

    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);
    @@ -708,13 +721,15 @@ 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))
    @@ -724,6 +739,10 @@ static int __cpuinit cache_add_dev(struc
    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);
    @@ -743,6 +762,9 @@ static int __cpuinit cache_add_dev(struc
    break;
    }
    }
    + if (!retval)
    + cpu_set(cpu, cache_dev_map);
    +
    return retval;
    }

    @@ -751,13 +773,14 @@ static void __cpuinit cache_remove_dev(s
    unsigned int cpu = sys_dev->id;
    unsigned long i;

    - 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,
    @@ -782,7 +805,7 @@ static int __cpuinit cacheinfo_cpu_callb

    static struct notifier_block __cpuinitdata cacheinfo_cpu_notifier =
    {
    - .notifier_call = cacheinfo_cpu_callback,
    + .notifier_call = cacheinfo_cpu_callback,
    };

    static int __cpuinit cache_sysfs_init(void)
    @@ -795,8 +818,8 @@ static int __cpuinit cache_sysfs_init(vo
    register_hotcpu_notifier(&cacheinfo_cpu_notifier);

    for_each_online_cpu(i) {
    - cacheinfo_cpu_callback(&cacheinfo_cpu_notifier, CPU_ONLINE,
    - (void *)(long)i);
    + struct sys_device *sys_dev = get_cpu_sysdev(i);
    + cache_add_dev(sys_dev);
    }

    return 0;
    -
    To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
    the body of a message to majordomo@vger.kernel.org
    More majordomo info at http://vger.kernel.org/majordomo-info.html
    Please read the FAQ at http://www.tux.org/lkml/
    \
     
     \ /
      Last update: 2007-07-16 16:13    [W:0.031 / U:0.044 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site