Fix uninitialised variable warning in mei-amt-version.c

Fix the following warning:

	Documentation/misc-devices/mei/mei-amt-version.c: In function 'main':
	Documentation/misc-devices/mei/mei-amt-version.c:103:5: warning: 'acmd.fd' is used uninitialized in this function [-Wuninitialized]
	  if (cl->fd != -1)
	     ^
	Documentation/misc-devices/mei/mei-amt-version.c:443:21: note: 'acmd.fd' was declared here
	  struct amt_host_if acmd;
			     ^

The call chain:

	-->main()
	   -->amt_host_if_init()
	      -->mei_init()
	         -->mei_deinit()

results in this on the first time through because main()::acmd has not yet been initialised.

To fix this, acmd.fd needs to be initialised to -1.

Signed-off-by David Howells <[email protected]>

cc Tomas Winkler <[email protected]>

cc Greg Kroah-Hartman <[email protected]>

 Documentation/misc-devices/mei/mei-amt-version.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

Documentation/misc-devices/mei/mei-amt-version.c +1 -1

index 49e4f770864a..7027a8da0ba0 100644
@@ -440,7 +440,7 @@ out:
 int main(int argc, char **argv)
 {
 	struct amt_code_versions ver;
-	struct amt_host_if acmd;
+	struct amt_host_if acmd = { .mei_cl.fd = -1 };
 	unsigned int i;
 	uint32_t status;
 	int ret;

But it turns out that call of mei_deinit() isn't needed at all. All of the members of mei_cl will be set later in mei_init() and none will be used before they are set. So we can simply drop this call of mei_deinit()."

Is that analysis (still) correct?

Quoted 6 lines · Paul Bolle

But it turns out that call of mei_deinit() isn't needed at all. All of the members of mei_cl will be set later in mei_init() and none will be used before they are set. So we can simply drop this call of mei_deinit()."

Is that analysis (still) correct?

It looks true as the code stands. Can you send me your patch?

From: Paul Bolle <[email protected]>

Building mei-amt-version.o triggers a GCC warning:

    Documentation/misc-devices/mei/mei-amt-version.c: In function 'main':
    Documentation/misc-devices/mei/mei-amt-version.c:103:5: warning: 'acmd.fd' is used uninitialized in this function [-Wuninitialized]
      if (cl->fd != -1)
         ^
    Documentation/misc-devices/mei/mei-amt-version.c:443:21: note: 'acmd.fd' was declared here
      struct amt_host_if acmd;
                         ^

GCC is correct. See, the call chain that GCC detects must be

    main()
        amt_host_if_init()
            mei_init()
                mei_deinit()

But when we enter mei_deinit() struct amt_host_if acmd is still unitialized. That makes the test for (effectively) amt_host_if->mei_cl->fd bogus.

But it turns out that call of mei_deinit() isn't needed at all. All of the members of mei_cl will be set later in mei_init() and none will be used before they are set. So we can simply drop this call of mei_deinit().

Signed-off-by Paul Bolle <[email protected]>

-----Original Message-----
From: David Howells [mailto:[email protected]]
Sent: Friday, January 03, 2014 18:34
To: Paul Bolle
Cc: [email protected]; [email protected]; Greg Kroah-Hartman; Winkler, Tomas; [email protected]
Subject: Re: [PATCH 7/7] Fix uninitialised variable warning in mei-amt-version.c

Paul Bolle <[email protected]> wrote:

Quoted 6 lines

But it turns out that call of mei_deinit() isn't needed at all. All of the members of mei_cl will be set later in mei_init() and none will be used before they are set. So we can simply drop this call of mei_deinit()."

Is that analysis (still) correct?

It looks true as the code stands. Can you send me your patch?