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-rw-r--r--kernel/trace/trace.c32
-rw-r--r--kernel/trace/trace_selftest.c1
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;