[ftrace/kprobes PATCH 1/3] tracing/uprobes: Fix to return -EFAULT if copy_from_user failed

[Masami Hiramatsu]

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().

Reported-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
Signed-off-by: Masami Hiramatsu <mhiramat@xxxxxxxxxx>
---
 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 12bdbdf772ed..63e99ee716fe 100644
--- a/kernel/trace/trace_uprobe.c
+++ b/kernel/trace/trace_uprobe.c
@@ -104,7 +104,7 @@ 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