From ebb3c4c4cb81d64cc041356915ec015e2c57092a Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Mon, 6 Apr 2009 11:45:05 +0200 Subject: [PATCH] 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 Cc: Paul Mackerras Cc: Corey Ashford LKML-Reference: <20090406094517.899767331@chello.nl> Signed-off-by: Ingo Molnar --- kernel/perf_counter.c | 33 +++++++++++++++++++++------------ 1 file changed, 21 insertions(+), 12 deletions(-) diff --git a/kernel/perf_counter.c b/kernel/perf_counter.c index 195e976eb07..c841563de04 100644 --- 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;