Messages in this thread Patch in this message | | | From | "Fenghua Yu" <> | Subject | [PATCH] drivers/hwmon/pkgtemp: Fix improper locking in CPU hot remove | Date | Wed, 18 Aug 2010 15:53:47 -0700 |
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From: Fenghua Yu <fenghua.yu@intel.com>
When a sibling is added to dev_list after a cpu is hot-removed, pdev_list_mutex has been locked already. But pkgtemp_device_add() tries to lock pdev_list_mutex again. This is incorrect. The patch fixes this issue.
The patch also removes __cpuinit for pkgtemp_device_add() to avoid section mismatch warning.
Signed-off-by: Fenghua Yu <fenghua.yu@intel.com> --- drivers/hwmon/pkgtemp.c | 18 +++++++++++++----- 1 files changed, 13 insertions(+), 5 deletions(-)
diff --git a/drivers/hwmon/pkgtemp.c b/drivers/hwmon/pkgtemp.c index 74157fc..928a016 100644 --- a/drivers/hwmon/pkgtemp.c +++ b/drivers/hwmon/pkgtemp.c @@ -276,7 +276,7 @@ struct pdev_entry { static LIST_HEAD(pdev_list); static DEFINE_MUTEX(pdev_list_mutex); -static int __cpuinit pkgtemp_device_add(unsigned int cpu) +static int pkgtemp_device_add(unsigned int cpu) { int err; struct platform_device *pdev; @@ -341,26 +341,34 @@ static void pkgtemp_device_remove(unsigned int cpu) { struct pdev_entry *p, *n; unsigned int i; - int err; - mutex_lock(&pdev_list_mutex); list_for_each_entry_safe(p, n, &pdev_list, list) { if (p->cpu != cpu) continue; + mutex_lock(&pdev_list_mutex); platform_device_unregister(p->pdev); list_del(&p->list); kfree(p); + mutex_unlock(&pdev_list_mutex); + /* + * Select one of removed cpu's siblings to represent sensor + * for this package. + * If there is no more running sibling in a package, the + * package sensor for this package is not available to user + * space any more. + */ for_each_cpu(i, cpu_core_mask(cpu)) { + int err; + if (i != cpu) { err = pkgtemp_device_add(i); if (!err) break; } } - break; + return; } - mutex_unlock(&pdev_list_mutex); } static int __cpuinit pkgtemp_cpu_callback(struct notifier_block *nfb, -- 1.6.0.3
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