[for-next][PATCH 13/18] tracing/uprobes: Fix to return -EFAULT if copy_from_user failed

[Steven Rostedt]

From: Masami Hiramatsu <mhiramat@xxxxxxxxxx>

Fix probe_mem_read() to return -EFAULT if copy_from_user()
failed. The copy_from_user() returns remaining bytes
when it failed, but probe_mem_read() caller expects it
returns error code like as probe_kernel_read().

Link: http://lkml.kernel.org/r/153547306719.26502.8353484532699160223.stgit@devbox

Reported-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
Signed-off-by: Masami Hiramatsu <mhiramat@xxxxxxxxxx>
Signed-off-by: Steven Rostedt (VMware) <rostedt@xxxxxxxxxxx>
---
 kernel/trace/trace_uprobe.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/kernel/trace/trace_uprobe.c b/kernel/trace/trace_uprobe.c
index 394b93572506..31ea48eceda1 100644
--- a/kernel/trace/trace_uprobe.c
+++ b/kernel/trace/trace_uprobe.c
@@ -105,7 +105,7 @@ probe_mem_read(void *dest, void *src, size_t size)
 {
 	void __user *vaddr = (void __force __user *)src;
 
-	return copy_from_user(dest, vaddr, size);
+	return copy_from_user(dest, vaddr, size) ? -EFAULT : 0;
 }
 /*
  * Fetch a null-terminated string. Caller MUST set *(u32 *)dest with max
-- 
2.19.0