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authorJan Beulich <jbeulich@novell.com>2010-09-13 10:11:05 +0000
committerGuenter Roeck <guenter.roeck@ericsson.com>2010-09-24 11:44:18 -0700
commitd9bca4358286584cc22f4261ee3a60cad01aa4d4 (patch)
treef18ecad6c5d1983d6c4b33544e405fb9680f000c
parent89a3fd35ba0318a7208e2c8d8ca6189f567d4a93 (diff)
x86/hwmon: avoid deadlock on CPU removal in pkgtemp
pkgtemp_device_remove(), holding the list protecting mutex, calls pkgtemp_device_add(), which itself wants to acquire the same mutex. Holding the mutex over the entire loop body in pkgtemp_device_remove() isn't really necessary, as long as the loop gets exited after processing the matched CPU. Once exiting the loop after removing an eventual match, there's no need for using the "safe" list iterator anymore. Signed-off-by: Jan Beulich <jbeulich@novell.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Signed-off-by: Guenter Roeck <guenter.roeck@ericsson.com>
-rw-r--r--drivers/hwmon/pkgtemp.c7
1 files changed, 4 insertions, 3 deletions
diff --git a/drivers/hwmon/pkgtemp.c b/drivers/hwmon/pkgtemp.c
index 74157fcda6ed..844957333fe5 100644
--- a/drivers/hwmon/pkgtemp.c
+++ b/drivers/hwmon/pkgtemp.c
@@ -339,17 +339,18 @@ exit:
#ifdef CONFIG_HOTPLUG_CPU
static void pkgtemp_device_remove(unsigned int cpu)
{
- struct pdev_entry *p, *n;
+ struct pdev_entry *p;
unsigned int i;
int err;
mutex_lock(&pdev_list_mutex);
- list_for_each_entry_safe(p, n, &pdev_list, list) {
+ list_for_each_entry(p, &pdev_list, list) {
if (p->cpu != cpu)
continue;
platform_device_unregister(p->pdev);
list_del(&p->list);
+ mutex_unlock(&pdev_list_mutex);
kfree(p);
for_each_cpu(i, cpu_core_mask(cpu)) {
if (i != cpu) {
@@ -358,7 +359,7 @@ static void pkgtemp_device_remove(unsigned int cpu)
break;
}
}
- break;
+ return;
}
mutex_unlock(&pdev_list_mutex);
}