7 files changed, 119 insertions, 118 deletions

diff --git a/kernel/cgroup_freezer.c b/kernel/cgroup_freezer.c
index 59e9ef6aab40..eb3f34d57419 100644
--- a/kernel/cgroup_freezer.c
+++ b/kernel/cgroup_freezer.c
@@ -47,17 +47,20 @@ static inline struct freezer *task_freezer(struct task_struct *task)
                             struct freezer, css);
 }
 
-int cgroup_frozen(struct task_struct *task)
+int cgroup_freezing_or_frozen(struct task_struct *task)
 {
         struct freezer *freezer;
         enum freezer_state state;
 
         task_lock(task);
         freezer = task_freezer(task);
-        state = freezer->state;
+        if (!freezer->css.cgroup->parent)
+                state = CGROUP_THAWED; /* root cgroup can't be frozen */
+        else
+                state = freezer->state;
         task_unlock(task);
 
-        return state == CGROUP_FROZEN;
+        return (state == CGROUP_FREEZING) || (state == CGROUP_FROZEN);
 }
 
 /*
diff --git a/kernel/kgdb.c b/kernel/kgdb.c
index 761fdd2b3034..11f3515ca83f 100644
--- a/kernel/kgdb.c
+++ b/kernel/kgdb.c
@@ -69,9 +69,16 @@ struct kgdb_state {
         struct pt_regs          *linux_regs;
 };
 
+/* Exception state values */
+#define DCPU_WANT_MASTER 0x1 /* Waiting to become a master kgdb cpu */
+#define DCPU_NEXT_MASTER 0x2 /* Transition from one master cpu to another */
+#define DCPU_IS_SLAVE    0x4 /* Slave cpu enter exception */
+#define DCPU_SSTEP       0x8 /* CPU is single stepping */
+
 static struct debuggerinfo_struct {
         void                    *debuggerinfo;
         struct task_struct      *task;
+        int                     exception_state;
 } kgdb_info[NR_CPUS];
 
 /**
@@ -391,27 +398,22 @@ int kgdb_mem2hex(char *mem, char *buf, int count)
 
 /*
  * Copy the binary array pointed to by buf into mem.  Fix $, #, and
- * 0x7d escaped with 0x7d.  Return a pointer to the character after
- * the last byte written.
+ * 0x7d escaped with 0x7d. Return -EFAULT on failure or 0 on success.
+ * The input buf is overwitten with the result to write to mem.
  */
 static int kgdb_ebin2mem(char *buf, char *mem, int count)
 {
-        int err = 0;
-        char c;
+        int size = 0;
+        char *c = buf;
 
         while (count-- > 0) {
-                c = *buf++;
-                if (c == 0x7d)
-                        c = *buf++ ^ 0x20;
-
-                err = probe_kernel_write(mem, &c, 1);
-                if (err)
-                        break;
-
-                mem++;
+                c[size] = *buf++;
+                if (c[size] == 0x7d)
+                        c[size] = *buf++ ^ 0x20;
+                size++;
         }
 
-        return err;
+        return probe_kernel_write(mem, c, size);
 }
 
 /*
@@ -563,49 +565,6 @@ static struct task_struct *getthread(struct pt_regs *regs, int tid)
 }
 
 /*
- * CPU debug state control:
- */
-
-#ifdef CONFIG_SMP
-static void kgdb_wait(struct pt_regs *regs)
-{
-        unsigned long flags;
-        int cpu;
-
-        local_irq_save(flags);
-        cpu = raw_smp_processor_id();
-        kgdb_info[cpu].debuggerinfo = regs;
-        kgdb_info[cpu].task = current;
-        /*
-         * Make sure the above info reaches the primary CPU before
-         * our cpu_in_kgdb[] flag setting does:
-         */
-        smp_wmb();
-        atomic_set(&cpu_in_kgdb[cpu], 1);
-
-        /* Disable any cpu specific hw breakpoints */
-        kgdb_disable_hw_debug(regs);
-
-        /* Wait till primary CPU is done with debugging */
-        while (atomic_read(&passive_cpu_wait[cpu]))
-                cpu_relax();
-
-        kgdb_info[cpu].debuggerinfo = NULL;
-        kgdb_info[cpu].task = NULL;
-
-        /* fix up hardware debug registers on local cpu */
-        if (arch_kgdb_ops.correct_hw_break)
-                arch_kgdb_ops.correct_hw_break();
-
-        /* Signal the primary CPU that we are done: */
-        atomic_set(&cpu_in_kgdb[cpu], 0);
-        touch_softlockup_watchdog_sync();
-        clocksource_touch_watchdog();
-        local_irq_restore(flags);
-}
-#endif
-
-/*
  * Some architectures need cache flushes when we set/clear a
  * breakpoint:
  */
@@ -1400,34 +1359,13 @@ static int kgdb_reenter_check(struct kgdb_state *ks)
         return 1;
 }
 
-/*
- * kgdb_handle_exception() - main entry point from a kernel exception
- *
- * Locking hierarchy:
- *      interface locks, if any (begin_session)
- *      kgdb lock (kgdb_active)
- */
-int
-kgdb_handle_exception(int evector, int signo, int ecode, struct pt_regs *regs)
+static int kgdb_cpu_enter(struct kgdb_state *ks, struct pt_regs *regs)
 {
-        struct kgdb_state kgdb_var;
-        struct kgdb_state *ks = &kgdb_var;
         unsigned long flags;
         int sstep_tries = 100;
         int error = 0;
         int i, cpu;
-
-        ks->cpu                 = raw_smp_processor_id();
-        ks->ex_vector           = evector;
-        ks->signo               = signo;
-        ks->ex_vector           = evector;
-        ks->err_code            = ecode;
-        ks->kgdb_usethreadid    = 0;
-        ks->linux_regs          = regs;
-
-        if (kgdb_reenter_check(ks))
-                return 0; /* Ouch, double exception ! */
-
+        int trace_on = 0;
 acquirelock:
         /*
          * Interrupts will be restored by the 'trap return' code, except when
@@ -1435,13 +1373,43 @@ acquirelock:
          */
         local_irq_save(flags);
 
-        cpu = raw_smp_processor_id();
+        cpu = ks->cpu;
+        kgdb_info[cpu].debuggerinfo = regs;
+        kgdb_info[cpu].task = current;
+        /*
+         * Make sure the above info reaches the primary CPU before
+         * our cpu_in_kgdb[] flag setting does:
+         */
+        atomic_inc(&cpu_in_kgdb[cpu]);
 
         /*
-         * Acquire the kgdb_active lock:
+         * CPU will loop if it is a slave or request to become a kgdb
+         * master cpu and acquire the kgdb_active lock:
          */
-        while (atomic_cmpxchg(&kgdb_active, -1, cpu) != -1)
+        while (1) {
+                if (kgdb_info[cpu].exception_state & DCPU_WANT_MASTER) {
+                        if (atomic_cmpxchg(&kgdb_active, -1, cpu) == cpu)
+                                break;
+                } else if (kgdb_info[cpu].exception_state & DCPU_IS_SLAVE) {
+                        if (!atomic_read(&passive_cpu_wait[cpu]))
+                                goto return_normal;
+                } else {
+return_normal:
+                        /* Return to normal operation by executing any
+                         * hw breakpoint fixup.
+                         */
+                        if (arch_kgdb_ops.correct_hw_break)
+                                arch_kgdb_ops.correct_hw_break();
+                        if (trace_on)
+                                tracing_on();
+                        atomic_dec(&cpu_in_kgdb[cpu]);
+                        touch_softlockup_watchdog_sync();
+                        clocksource_touch_watchdog();
+                        local_irq_restore(flags);
+                        return 0;
+                }
                 cpu_relax();
+        }
 
         /*
          * For single stepping, try to only enter on the processor
@@ -1475,9 +1443,6 @@ acquirelock:
         if (kgdb_io_ops->pre_exception)
                 kgdb_io_ops->pre_exception();
 
-        kgdb_info[ks->cpu].debuggerinfo = ks->linux_regs;
-        kgdb_info[ks->cpu].task = current;
-
         kgdb_disable_hw_debug(ks->linux_regs);
 
         /*
@@ -1486,15 +1451,9 @@ acquirelock:
          */
         if (!kgdb_single_step) {
                 for (i = 0; i < NR_CPUS; i++)
-                        atomic_set(&passive_cpu_wait[i], 1);
+                        atomic_inc(&passive_cpu_wait[i]);
         }
 
-        /*
-         * spin_lock code is good enough as a barrier so we don't
-         * need one here:
-         */
-        atomic_set(&cpu_in_kgdb[ks->cpu], 1);
-
 #ifdef CONFIG_SMP
         /* Signal the other CPUs to enter kgdb_wait() */
         if ((!kgdb_single_step) && kgdb_do_roundup)
@@ -1518,6 +1477,9 @@ acquirelock:
         kgdb_single_step = 0;
         kgdb_contthread = current;
         exception_level = 0;
+        trace_on = tracing_is_on();
+        if (trace_on)
+                tracing_off();
 
         /* Talk to debugger with gdbserial protocol */
         error = gdb_serial_stub(ks);
@@ -1526,13 +1488,11 @@ acquirelock:
         if (kgdb_io_ops->post_exception)
                 kgdb_io_ops->post_exception();
 
-        kgdb_info[ks->cpu].debuggerinfo = NULL;
-        kgdb_info[ks->cpu].task = NULL;
-        atomic_set(&cpu_in_kgdb[ks->cpu], 0);
+        atomic_dec(&cpu_in_kgdb[ks->cpu]);
 
         if (!kgdb_single_step) {
                 for (i = NR_CPUS-1; i >= 0; i--)
-                        atomic_set(&passive_cpu_wait[i], 0);
+                        atomic_dec(&passive_cpu_wait[i]);
                 /*
                  * Wait till all the CPUs have quit
                  * from the debugger.
@@ -1551,6 +1511,8 @@ kgdb_restore:
                 else
                         kgdb_sstep_pid = 0;
         }
+        if (trace_on)
+                tracing_on();
         /* Free kgdb_active */
         atomic_set(&kgdb_active, -1);
         touch_softlockup_watchdog_sync();
@@ -1560,13 +1522,52 @@ kgdb_restore:
         return error;
 }
 
+/*
+ * kgdb_handle_exception() - main entry point from a kernel exception
+ *
+ * Locking hierarchy:
+ *      interface locks, if any (begin_session)
+ *      kgdb lock (kgdb_active)
+ */
+int
+kgdb_handle_exception(int evector, int signo, int ecode, struct pt_regs *regs)
+{
+        struct kgdb_state kgdb_var;
+        struct kgdb_state *ks = &kgdb_var;
+        int ret;
+
+        ks->cpu                 = raw_smp_processor_id();
+        ks->ex_vector           = evector;
+        ks->signo               = signo;
+        ks->ex_vector           = evector;
+        ks->err_code            = ecode;
+        ks->kgdb_usethreadid    = 0;
+        ks->linux_regs          = regs;
+
+        if (kgdb_reenter_check(ks))
+                return 0; /* Ouch, double exception ! */
+        kgdb_info[ks->cpu].exception_state |= DCPU_WANT_MASTER;
+        ret = kgdb_cpu_enter(ks, regs);
+        kgdb_info[ks->cpu].exception_state &= ~DCPU_WANT_MASTER;
+        return ret;
+}
+
 int kgdb_nmicallback(int cpu, void *regs)
 {
 #ifdef CONFIG_SMP
+        struct kgdb_state kgdb_var;
+        struct kgdb_state *ks = &kgdb_var;
+
+        memset(ks, 0, sizeof(struct kgdb_state));
+        ks->cpu                 = cpu;
+        ks->linux_regs          = regs;
+
         if (!atomic_read(&cpu_in_kgdb[cpu]) &&
-                        atomic_read(&kgdb_active) != cpu &&
-                        atomic_read(&cpu_in_kgdb[atomic_read(&kgdb_active)])) {
-                kgdb_wait((struct pt_regs *)regs);
+            atomic_read(&kgdb_active) != -1 &&
+            atomic_read(&kgdb_active) != cpu) {
+                kgdb_info[cpu].exception_state |= DCPU_IS_SLAVE;
+                kgdb_cpu_enter(ks, regs);
+                kgdb_info[cpu].exception_state &= ~DCPU_IS_SLAVE;
                 return 0;
         }
 #endif
@@ -1742,11 +1743,11 @@ EXPORT_SYMBOL_GPL(kgdb_unregister_io_module);
  */
 void kgdb_breakpoint(void)
 {
-        atomic_set(&kgdb_setting_breakpoint, 1);
+        atomic_inc(&kgdb_setting_breakpoint);
         wmb(); /* Sync point before breakpoint */
         arch_kgdb_breakpoint();
         wmb(); /* Sync point after breakpoint */
-        atomic_set(&kgdb_setting_breakpoint, 0);
+        atomic_dec(&kgdb_setting_breakpoint);
 }
 EXPORT_SYMBOL_GPL(kgdb_breakpoint);
 
diff --git a/kernel/power/process.c b/kernel/power/process.c
index 5ade1bdcf366..71ae29052ab6 100644
--- a/kernel/power/process.c
+++ b/kernel/power/process.c
@@ -88,12 +88,11 @@ static int try_to_freeze_tasks(bool sig_only)
                 printk(KERN_ERR "Freezing of tasks failed after %d.%02d seconds "
                                 "(%d tasks refusing to freeze):\n",
                                 elapsed_csecs / 100, elapsed_csecs % 100, todo);
-                show_state();
                 read_lock(&tasklist_lock);
                 do_each_thread(g, p) {
                         task_lock(p);
                         if (freezing(p) && !freezer_should_skip(p))
-                                printk(KERN_ERR " %s\n", p->comm);
+                                sched_show_task(p);
                         cancel_freezing(p);
                         task_unlock(p);
                 } while_each_thread(g, p);
@@ -145,7 +144,7 @@ static void thaw_tasks(bool nosig_only)
                 if (nosig_only && should_send_signal(p))
                         continue;
 
-                if (cgroup_frozen(p))
+                if (cgroup_freezing_or_frozen(p))
                         continue;
 
                 thaw_process(p);
diff --git a/kernel/sched.c b/kernel/sched.c
index 49d2fa7b687a..528a10592c16 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -5387,7 +5387,7 @@ int set_cpus_allowed_ptr(struct task_struct *p, const struct cpumask *new_mask)
 
                 get_task_struct(mt);
                 task_rq_unlock(rq, &flags);
-                wake_up_process(rq->migration_thread);
+                wake_up_process(mt);
                 put_task_struct(mt);
                 wait_for_completion(&req.done);
                 tlb_migrate_finish(p->mm);
diff --git a/kernel/sched_debug.c b/kernel/sched_debug.c
index 67f95aada4b9..9b49db144037 100644
--- a/kernel/sched_debug.c
+++ b/kernel/sched_debug.c
@@ -518,8 +518,4 @@ void proc_sched_set_task(struct task_struct *p)
         p->se.nr_wakeups_idle                   = 0;
         p->sched_info.bkl_count                 = 0;
 #endif
-        p->se.sum_exec_runtime                  = 0;
-        p->se.prev_sum_exec_runtime             = 0;
-        p->nvcsw                                = 0;
-        p->nivcsw                               = 0;
 }
diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c
index d1187ef20caf..9a0f9bf6a37b 100644
--- a/kernel/trace/ring_buffer.c
+++ b/kernel/trace/ring_buffer.c
@@ -1209,18 +1209,19 @@ rb_remove_pages(struct ring_buffer_per_cpu *cpu_buffer, unsigned nr_pages)
 
         for (i = 0; i < nr_pages; i++) {
                 if (RB_WARN_ON(cpu_buffer, list_empty(cpu_buffer->pages)))
-                        return;
+                        goto out;
                 p = cpu_buffer->pages->next;
                 bpage = list_entry(p, struct buffer_page, list);
                 list_del_init(&bpage->list);
                 free_buffer_page(bpage);
         }
         if (RB_WARN_ON(cpu_buffer, list_empty(cpu_buffer->pages)))
-                return;
+                goto out;
 
         rb_reset_cpu(cpu_buffer);
         rb_check_pages(cpu_buffer);
 
+out:
         spin_unlock_irq(&cpu_buffer->reader_lock);
 }
 
@@ -1237,7 +1238,7 @@ rb_insert_pages(struct ring_buffer_per_cpu *cpu_buffer,
 
         for (i = 0; i < nr_pages; i++) {
                 if (RB_WARN_ON(cpu_buffer, list_empty(pages)))
-                        return;
+                        goto out;
                 p = pages->next;
                 bpage = list_entry(p, struct buffer_page, list);
                 list_del_init(&bpage->list);
@@ -1246,6 +1247,7 @@ rb_insert_pages(struct ring_buffer_per_cpu *cpu_buffer,
         rb_reset_cpu(cpu_buffer);
         rb_check_pages(cpu_buffer);
 
+out:
         spin_unlock_irq(&cpu_buffer->reader_lock);
 }
 
diff --git a/kernel/trace/trace_clock.c b/kernel/trace/trace_clock.c
index 6fbfb8f417b9..9d589d8dcd1a 100644
--- a/kernel/trace/trace_clock.c
+++ b/kernel/trace/trace_clock.c
@@ -84,7 +84,7 @@ u64 notrace trace_clock_global(void)
         int this_cpu;
         u64 now;
 
-        raw_local_irq_save(flags);
+        local_irq_save(flags);
 
         this_cpu = raw_smp_processor_id();
         now = cpu_clock(this_cpu);
@@ -110,7 +110,7 @@ u64 notrace trace_clock_global(void)
         arch_spin_unlock(&trace_clock_struct.lock);
 
  out:
-        raw_local_irq_restore(flags);
+        local_irq_restore(flags);
 
         return now;
 }