diff options
Diffstat (limited to 'kernel/trace/trace.c')
| -rw-r--r-- | kernel/trace/trace.c | 25 |
1 files changed, 22 insertions, 3 deletions
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 4529e264cb86..b8870078ef58 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -1928,9 +1928,10 @@ update_max_tr_single(struct trace_array *tr, struct task_struct *tsk, int cpu) * place on this CPU. We fail to record, but we reset * the max trace buffer (no one writes directly to it) * and flag that it failed. + * Another reason is resize is in progress. */ trace_array_printk_buf(tr->max_buffer.buffer, _THIS_IP_, - "Failed to swap buffers due to commit in progress\n"); + "Failed to swap buffers due to commit or resize in progress\n"); } WARN_ON_ONCE(ret && ret != -EAGAIN && ret != -EBUSY); @@ -3118,6 +3119,7 @@ static void __ftrace_trace_stack(struct trace_buffer *buffer, struct ftrace_stack *fstack; struct stack_entry *entry; int stackidx; + void *ptr; /* * Add one, for this function and the call to save_stack_trace() @@ -3161,9 +3163,25 @@ static void __ftrace_trace_stack(struct trace_buffer *buffer, trace_ctx); if (!event) goto out; - entry = ring_buffer_event_data(event); + ptr = ring_buffer_event_data(event); + entry = ptr; + + /* + * For backward compatibility reasons, the entry->caller is an + * array of 8 slots to store the stack. This is also exported + * to user space. The amount allocated on the ring buffer actually + * holds enough for the stack specified by nr_entries. This will + * go into the location of entry->caller. Due to string fortifiers + * checking the size of the destination of memcpy() it triggers + * when it detects that size is greater than 8. To hide this from + * the fortifiers, we use "ptr" and pointer arithmetic to assign caller. + * + * The below is really just: + * memcpy(&entry->caller, fstack->calls, size); + */ + ptr += offsetof(typeof(*entry), caller); + memcpy(ptr, fstack->calls, size); - memcpy(&entry->caller, fstack->calls, size); entry->size = nr_entries; if (!call_filter_check_discard(call, entry, buffer, event)) @@ -6764,6 +6782,7 @@ static int tracing_release_pipe(struct inode *inode, struct file *file) free_cpumask_var(iter->started); kfree(iter->fmt); + kfree(iter->temp); mutex_destroy(&iter->mutex); kfree(iter); |