On Fri, 2014-01-03 at 16:08 +0000, David Howells wrote:
> 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]>
I've been using a local patch now for quite some time. I currently use
it on v3.12.6. I haven't yet bothered to submit it. My (draft) commit
summary reads:
"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()."
Is that analysis (still) correct?
Paul Bolle
> Documentation/misc-devices/mei/mei-amt-version.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/Documentation/misc-devices/mei/mei-amt-version.c
> b/Documentation/misc-devices/mei/mei-amt-version.c
> index 49e4f770864a..7027a8da0ba0 100644
> --- a/Documentation/misc-devices/mei/mei-amt-version.c
> +++ b/Documentation/misc-devices/mei/mei-amt-version.c
> @@ -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;
>
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