Merge tag 'please-pull-tangchen' of git://git.kernel.org/pub/scm/linux/kernel/git/ras/ras into x86/urgent

Pull MCE fix from Tony Luck:

   "Fix problem in CMCI rediscovery code that was illegally
    migrating worker threads to other cpus."

Signed-off-by: Ingo Molnar <mingo@kernel.org>

1 files changed, 18 insertions, 13 deletions

diff --git a/arch/x86/kernel/cpu/mcheck/mce_intel.c b/arch/x86/kernel/cpu/mcheck/mce_intel.c
index 5f88abf07e9c..4f9a3cbfc4a3 100644
--- a/arch/x86/kernel/cpu/mcheck/mce_intel.c
+++ b/arch/x86/kernel/cpu/mcheck/mce_intel.c
@@ -285,34 +285,39 @@ void cmci_clear(void)
         raw_spin_unlock_irqrestore(&cmci_discover_lock, flags);
 }
 
+static long cmci_rediscover_work_func(void *arg)
+{
+        int banks;
+
+        /* Recheck banks in case CPUs don't all have the same */
+        if (cmci_supported(&banks))
+                cmci_discover(banks);
+
+        return 0;
+}
+
 /*
  * After a CPU went down cycle through all the others and rediscover
  * Must run in process context.
  */
 void cmci_rediscover(int dying)
 {
-        int banks;
-        int cpu;
-        cpumask_var_t old;
+        int cpu, banks;
 
         if (!cmci_supported(&banks))
                 return;
-        if (!alloc_cpumask_var(&old, GFP_KERNEL))
-                return;
-        cpumask_copy(old, &current->cpus_allowed);
 
         for_each_online_cpu(cpu) {
                 if (cpu == dying)
                         continue;
-                if (set_cpus_allowed_ptr(current, cpumask_of(cpu)))
+
+                if (cpu == smp_processor_id()) {
+                        cmci_rediscover_work_func(NULL);
                         continue;
-                /* Recheck banks in case CPUs don't all have the same */
-                if (cmci_supported(&banks))
-                        cmci_discover(banks);
-        }
+                }
 
-        set_cpus_allowed_ptr(current, old);
-        free_cpumask_var(old);
+                work_on_cpu(cpu, cmci_rediscover_work_func, NULL);
+        }
 }
 
 /*