perf_counter: fix the mlock accounting

Reading through the code I saw I forgot the finish the mlock accounting.
Do so now.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com>
LKML-Reference: <20090406094517.899767331@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

diff --git a/kernel/perf_counter.c b/kernel/perf_counter.c
index 195e976..c841563 100644 (file)
--- a/kernel/perf_counter.c
+++ b/kernel/perf_counter.c
@@ -1461,13 +1461,14 @@ static void perf_mmap_close(struct vm_area_struct *vma)
 
        if (atomic_dec_and_mutex_lock(&counter->mmap_count,
                                      &counter->mmap_mutex)) {
+               vma->vm_mm->locked_vm -= counter->data->nr_pages + 1;
                perf_mmap_data_free(counter);
                mutex_unlock(&counter->mmap_mutex);
        }
 }
 
 static struct vm_operations_struct perf_mmap_vmops = {
-       .open = perf_mmap_open,
+       .open  = perf_mmap_open,
        .close = perf_mmap_close,
        .fault = perf_mmap_fault,
 };
@@ -1499,24 +1500,32 @@ static int perf_mmap(struct file *file, struct vm_area_struct *vma)
        if (vma->vm_pgoff != 0)
                return -EINVAL;
 
-       locked = vma_size >>  PAGE_SHIFT;
-       locked += vma->vm_mm->locked_vm;
+       mutex_lock(&counter->mmap_mutex);
+       if (atomic_inc_not_zero(&counter->mmap_count)) {
+               if (nr_pages != counter->data->nr_pages)
+                       ret = -EINVAL;
+               goto unlock;
+       }
+
+       locked = vma->vm_mm->locked_vm;
+       locked += nr_pages + 1;
 
        lock_limit = current->signal->rlim[RLIMIT_MEMLOCK].rlim_cur;
        lock_limit >>= PAGE_SHIFT;
 
-       if ((locked > lock_limit) && !capable(CAP_IPC_LOCK))
-               return -EPERM;
-
-       mutex_lock(&counter->mmap_mutex);
-       if (atomic_inc_not_zero(&counter->mmap_count))
-               goto out;
+       if ((locked > lock_limit) && !capable(CAP_IPC_LOCK)) {
+               ret = -EPERM;
+               goto unlock;
+       }
 
        WARN_ON(counter->data);
        ret = perf_mmap_data_alloc(counter, nr_pages);
-       if (!ret)
-               atomic_set(&counter->mmap_count, 1);
-out:
+       if (ret)
+               goto unlock;
+
+       atomic_set(&counter->mmap_count, 1);
+       vma->vm_mm->locked_vm += nr_pages + 1;
+unlock:
        mutex_unlock(&counter->mmap_mutex);
 
        vma->vm_flags &= ~VM_MAYWRITE;