diff options
| -rw-r--r-- | kernel/trace/trace.c | 32 | ||||
| -rw-r--r-- | kernel/trace/trace_selftest.c | 1 |
2 files changed, 24 insertions, 9 deletions
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 3271916ff03..0567f51bbea 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -249,24 +249,32 @@ __update_max_tr(struct trace_array *tr, struct task_struct *tsk, int cpu) tracing_record_cmdline(current); } +#define CHECK_COND(cond) \ + if (unlikely(cond)) { \ + tracing_disabled = 1; \ + WARN_ON(1); \ + return -1; \ + } + /** * check_pages - integrity check of trace buffers * * As a safty measure we check to make sure the data pages have not - * been corrupted. TODO: configure to disable this because it adds - * a bit of overhead. + * been corrupted. */ -void check_pages(struct trace_array_cpu *data) +int check_pages(struct trace_array_cpu *data) { struct page *page, *tmp; - BUG_ON(data->trace_pages.next->prev != &data->trace_pages); - BUG_ON(data->trace_pages.prev->next != &data->trace_pages); + CHECK_COND(data->trace_pages.next->prev != &data->trace_pages); + CHECK_COND(data->trace_pages.prev->next != &data->trace_pages); list_for_each_entry_safe(page, tmp, &data->trace_pages, lru) { - BUG_ON(page->lru.next->prev != &page->lru); - BUG_ON(page->lru.prev->next != &page->lru); + CHECK_COND(page->lru.next->prev != &page->lru); + CHECK_COND(page->lru.prev->next != &page->lru); } + + return 0; } /** @@ -280,7 +288,6 @@ void *head_page(struct trace_array_cpu *data) { struct page *page; - check_pages(data); if (list_empty(&data->trace_pages)) return NULL; @@ -2566,7 +2573,7 @@ tracing_entries_write(struct file *filp, const char __user *ubuf, { unsigned long val; char buf[64]; - int ret; + int i, ret; if (cnt >= sizeof(buf)) return -EINVAL; @@ -2635,8 +2642,15 @@ tracing_entries_write(struct file *filp, const char __user *ubuf, trace_free_page(); } + /* check integrity */ + for_each_tracing_cpu(i) + check_pages(global_trace.data[i]); + filp->f_pos += cnt; + /* If check pages failed, return ENOMEM */ + if (tracing_disabled) + cnt = -ENOMEM; out: max_tr.entries = global_trace.entries; mutex_unlock(&trace_types_lock); diff --git a/kernel/trace/trace_selftest.c b/kernel/trace/trace_selftest.c index 3877dd9102f..18c5423bc97 100644 --- a/kernel/trace/trace_selftest.c +++ b/kernel/trace/trace_selftest.c @@ -28,6 +28,7 @@ trace_test_buffer_cpu(struct trace_array *tr, struct trace_array_cpu *data) page = list_entry(data->trace_pages.next, struct page, lru); entries = page_address(page); + check_pages(data); if (head_page(data) != entries) goto failed; |