Re: [PATCH] staging: r8188eu: Fix uninitialized variable change_inx

From: Geert Uytterhoeven
Date: Fri Sep 06 2013 - 10:52:40 EST


On Fri, Sep 6, 2013 at 4:42 PM, Larry Finger <Larry.Finger@xxxxxxxxxxxx> wrote:
> On 09/06/2013 07:45 AM, Geert Uytterhoeven wrote:
>> drivers/staging/rtl8188eu/core/rtw_wlan_util.c: In function
>> âWMMOnAssocRspâ:
>> drivers/staging/rtl8188eu/core/rtw_wlan_util.c:634: warning: âchange_inxâ
>> may be used uninitialized in this function
>>
>> And the compiler is right: change_inx should be initialized to false.
>>
>> Signed-off-by: Geert Uytterhoeven <geert@xxxxxxxxxxxxxx>
>> ---
>> drivers/staging/rtl8188eu/core/rtw_wlan_util.c | 2 +-
>> 1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/drivers/staging/rtl8188eu/core/rtw_wlan_util.c
>> b/drivers/staging/rtl8188eu/core/rtw_wlan_util.c
>> index 013ea48..8018edd 100644
>> --- a/drivers/staging/rtl8188eu/core/rtw_wlan_util.c
>> +++ b/drivers/staging/rtl8188eu/core/rtw_wlan_util.c
>> @@ -631,7 +631,7 @@ void WMMOnAssocRsp(struct adapter *padapter)
>> inx[0] = 0; inx[1] = 1; inx[2] = 2; inx[3] = 3;
>>
>> if (pregpriv->wifi_spec == 1) {
>> - u32 j, tmp, change_inx;
>> + u32 j, tmp, change_inx = false;
>>
>> /* entry indx: 0->vo, 1->vi, 2->be, 3->bk. */
>> for (i = 0; i < 4; i++) {
>>
>
> Acked-by: Larry Finger <Larry.Finger@xxxxxxxxxxxx>
>
> This warning has not shown up on my x86_64 system with gcc 4.7.2. What
> architecture and gcc version were you using?

Good old gcc version 4.1.2 20061115 (prerelease) (Ubuntu 4.1.1-21) for m68k.

Recent versions of gcc no longer give warnings for uninitialized variables,
probably because it used to flood you with too many false positives.
This may please the -Werror camp, but once in a while the warnings do disclose
real bugs, so I tend to look at all regressions I encounter there.

I've just checked with m68k-linux-gcc 4.6.3 from crosstool on kernel.org, and
it doesn't give this warning (hmm, it does give other warnings, so I should have
a closer look...).

Gr{oetje,eeting}s,

Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds
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