[linux-next:master 556/6237] drivers/net/wireless/ath/wcn36xx/main.c:409:7: warning: Branch condition evaluates to a garbage value [clang-analyzer-core.uninitialized.Branch]

Thursday, 17 February 2022


tree:   https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git master
head:   763a906a02e961eedabab7dbedd16904a3bd0184
commit: d6f2746691cb10e484f15ab9e44e2cc2ccf9bd86 [556/6237] wcn36xx: Track the band and
channel we are tuned to
config: x86_64-randconfig-c007
(https://download.01.org/0day-ci/archive/20220217/202202170554.WYrgcFtq-lk...)
compiler: clang version 15.0.0 (https://github.com/llvm/llvm-project
0e628a783b935c70c80815db6c061ec84f884af5)
reproduce (this is a W=1 build):
         wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O
~/bin/make.cross
         chmod +x ~/bin/make.cross
         #
https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git/commi...
         git remote add linux-next
https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git
         git fetch --no-tags linux-next master
         git checkout d6f2746691cb10e484f15ab9e44e2cc2ccf9bd86
         # save the config file to linux build tree
         COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=x86_64
clang-analyzer

If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <yujie.liu(a)intel.com&gt;


clang-analyzer warnings: (new ones prefixed by >>)

...
> drivers/net/wireless/ath/wcn36xx/main.c:409:7: warning: Branch
condition evaluates to a garbage value [clang-analyzer-core.uninitialized.Branch]   
                 if (channel)
                        ^
    drivers/net/wireless/ath/wcn36xx/main.c:396:2: note: 'channel' declared
without an initial value
            struct ieee80211_channel *channel;
            ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    drivers/net/wireless/ath/wcn36xx/main.c:399:2: note: Loop condition is true.  Entering
loop body
            for (i = 0; i < ARRAY_SIZE(wcn->hw->wiphy->bands); i++) {
            ^
    drivers/net/wireless/ath/wcn36xx/main.c:401:7: note: Assuming 'band' is
non-null
                    if (!band)
                        ^~~~~
    drivers/net/wireless/ath/wcn36xx/main.c:401:3: note: Taking false branch
                    if (!band)
                    ^
    drivers/net/wireless/ath/wcn36xx/main.c:403:15: note: Assuming 'j' is >=
field 'n_channels'
                    for (j = 0; j < band->n_channels; j++) {
                                ^~~~~~~~~~~~~~~~~~~~
    drivers/net/wireless/ath/wcn36xx/main.c:403:3: note: Loop condition is false.
Execution continues on line 409
                    for (j = 0; j < band->n_channels; j++) {
                    ^
    drivers/net/wireless/ath/wcn36xx/main.c:409:7: note: Branch condition evaluates to a
garbage value
                    if (channel)
                        ^~~~~~~
    drivers/net/wireless/ath/wcn36xx/main.c:413:6: warning: Branch condition evaluates to
a garbage value [clang-analyzer-core.uninitialized.Branch]
            if (!channel) {
                ^

vim +409 drivers/net/wireless/ath/wcn36xx/main.c

5973a2947430a29 Loic Poulain     2020-08-24  390
5973a2947430a29 Loic Poulain     2020-08-24  391  static void
wcn36xx_change_opchannel(struct wcn36xx *wcn, int ch)
5973a2947430a29 Loic Poulain     2020-08-24  392  {
5973a2947430a29 Loic Poulain     2020-08-24  393  	struct ieee80211_vif *vif = NULL;
5973a2947430a29 Loic Poulain     2020-08-24  394  	struct wcn36xx_vif *tmp;
d6f2746691cb10e Bryan O'Donoghue 2022-01-15  395  	struct ieee80211_supported_band
*band;
d6f2746691cb10e Bryan O'Donoghue 2022-01-15  396  	struct ieee80211_channel *channel;
d6f2746691cb10e Bryan O'Donoghue 2022-01-15  397  	int i, j;
d6f2746691cb10e Bryan O'Donoghue 2022-01-15  398
d6f2746691cb10e Bryan O'Donoghue 2022-01-15  399  	for (i = 0; i <
ARRAY_SIZE(wcn->hw->wiphy->bands); i++) {
d6f2746691cb10e Bryan O'Donoghue 2022-01-15  400  		band =
wcn->hw->wiphy->bands[i];
d6f2746691cb10e Bryan O'Donoghue 2022-01-15  401  		if (!band)
d6f2746691cb10e Bryan O'Donoghue 2022-01-15  402  			break;
d6f2746691cb10e Bryan O'Donoghue 2022-01-15  403  		for (j = 0; j <
band->n_channels; j++) {
d6f2746691cb10e Bryan O'Donoghue 2022-01-15  404  			if
(HW_VALUE_CHANNEL(band->channels[j].hw_value) == ch) {
d6f2746691cb10e Bryan O'Donoghue 2022-01-15  405  				channel =
&band->channels[j];
d6f2746691cb10e Bryan O'Donoghue 2022-01-15  406  				break;
d6f2746691cb10e Bryan O'Donoghue 2022-01-15  407  			}
d6f2746691cb10e Bryan O'Donoghue 2022-01-15  408  		}
d6f2746691cb10e Bryan O'Donoghue 2022-01-15 @409  		if (channel)
d6f2746691cb10e Bryan O'Donoghue 2022-01-15  410  			break;
d6f2746691cb10e Bryan O'Donoghue 2022-01-15  411  	}
d6f2746691cb10e Bryan O'Donoghue 2022-01-15  412
d6f2746691cb10e Bryan O'Donoghue 2022-01-15  413  	if (!channel) {
d6f2746691cb10e Bryan O'Donoghue 2022-01-15  414  		wcn36xx_err("Cannot tune to
channel %d\n", ch);
d6f2746691cb10e Bryan O'Donoghue 2022-01-15  415  		return;
d6f2746691cb10e Bryan O'Donoghue 2022-01-15  416  	}
d6f2746691cb10e Bryan O'Donoghue 2022-01-15  417
d6f2746691cb10e Bryan O'Donoghue 2022-01-15  418  	wcn->band = band;
d6f2746691cb10e Bryan O'Donoghue 2022-01-15  419  	wcn->channel = channel;
5973a2947430a29 Loic Poulain     2020-08-24  420
5973a2947430a29 Loic Poulain     2020-08-24  421  	list_for_each_entry(tmp,
&wcn->vif_list, list) {
5973a2947430a29 Loic Poulain     2020-08-24  422  		vif = wcn36xx_priv_to_vif(tmp);
5973a2947430a29 Loic Poulain     2020-08-24  423  		wcn36xx_smd_switch_channel(wcn, vif,
ch);
5973a2947430a29 Loic Poulain     2020-08-24  424  	}
d6f2746691cb10e Bryan O'Donoghue 2022-01-15  425
d6f2746691cb10e Bryan O'Donoghue 2022-01-15  426  	return;
5973a2947430a29 Loic Poulain     2020-08-24  427  }
5973a2947430a29 Loic Poulain     2020-08-24  428

---
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