Re: [PATCH v2][next] wifi: iwlwifi: mvm: Use __counted_by() and avoid -Wfamnae warnings

Gustavo A. R. Silva
2024-09-13T10:14:20Z

On 10/08/24 22:26, kernel test robot wrote:
> Hi Gustavo,
>
> kernel test robot noticed the following build errors:
>
> [auto build test ERROR on wireless-next/main]
> [also build test ERROR on wireless/main linus/master v6.11-rc2 next-20240809]
> [If your patch is applied to the wrong git tree, kindly drop us a note.
> And when submitting patch, we suggest to use '--base' as documented in
> https://git-scm.com/docs/git-format-patch#_base_tree_information]
>
> url: https://github.com/intel-lab-lkp/linux/commits/Gustavo-A-R-Silva/wifi-iwlwifi-mvm-Use-__counted_by-and-avoid-Wfamnae-warnings/20240810-103759
> base: https://git.kernel.org/pub/scm/linux/kernel/git/wireless/wireless-next.git main
> patch link: https://lore.kernel.org/r/ZrZs5KL5Pz9tIinr%40cute
> patch subject: [PATCH v2][next] wifi: iwlwifi: mvm: Use __counted_by() and avoid -Wfamnae warnings
> config: riscv-allmodconfig (https://download.01.org/0day-ci/archive/20240811/202408110634.V68RFEtW-lkp@intel.com/config)
> compiler: clang version 20.0.0git (https://github.com/llvm/llvm-project f86594788ce93b696675c94f54016d27a6c21d18)
> reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20240811/202408110634.V68RFEtW-lkp@intel.com/reproduce)
>
> If you fix the issue in a separate patch/commit (i.e. not just a new version of
> the same patch/commit), kindly add following tags
> | Reported-by: kernel test robot <lkp@intel.com>
> | Closes: https://lore.kernel.org/oe-kbuild-all/202408110634.V68RFEtW-lkp@intel.com/
>
> All errors (new ones prefixed by >>):
>
> In file included from drivers/net/wireless/intel/iwlwifi/mvm/d3.c:7:
> In file included from include/linux/etherdevice.h:20:
> In file included from include/linux/if_ether.h:19:
> In file included from include/linux/skbuff.h:17:
> In file included from include/linux/bvec.h:10:
> In file included from include/linux/highmem.h:8:
> In file included from include/linux/cacheflush.h:5:
> In file included from arch/riscv/include/asm/cacheflush.h:9:
> In file included from include/linux/mm.h:2228:
> include/linux/vmstat.h:500:43: warning: arithmetic between different enumeration types ('enum zone_stat_item' and 'enum numa_stat_item') [-Wenum-enum-conversion]
> 500 | return vmstat_text[NR_VM_ZONE_STAT_ITEMS +
> | ~~~~~~~~~~~~~~~~~~~~~ ^
> 501 | item];
> | ~~~~
> include/linux/vmstat.h:507:43: warning: arithmetic between different enumeration types ('enum zone_stat_item' and 'enum numa_stat_item') [-Wenum-enum-conversion]
> 507 | return vmstat_text[NR_VM_ZONE_STAT_ITEMS +
> | ~~~~~~~~~~~~~~~~~~~~~ ^
> 508 | NR_VM_NUMA_EVENT_ITEMS +
> | ~~~~~~~~~~~~~~~~~~~~~~
> include/linux/vmstat.h:514:36: warning: arithmetic between different enumeration types ('enum node_stat_item' and 'enum lru_list') [-Wenum-enum-conversion]
> 514 | return node_stat_name(NR_LRU_BASE + lru) + 3; // skip "nr_"
> | ~~~~~~~~~~~ ^ ~~~
> include/linux/vmstat.h:519:43: warning: arithmetic between different enumeration types ('enum zone_stat_item' and 'enum numa_stat_item') [-Wenum-enum-conversion]
> 519 | return vmstat_text[NR_VM_ZONE_STAT_ITEMS +
> | ~~~~~~~~~~~~~~~~~~~~~ ^
> 520 | NR_VM_NUMA_EVENT_ITEMS +
> | ~~~~~~~~~~~~~~~~~~~~~~
> include/linux/vmstat.h:528:43: warning: arithmetic between different enumeration types ('enum zone_stat_item' and 'enum numa_stat_item') [-Wenum-enum-conversion]
> 528 | return vmstat_text[NR_VM_ZONE_STAT_ITEMS +
> | ~~~~~~~~~~~~~~~~~~~~~ ^
> 529 | NR_VM_NUMA_EVENT_ITEMS +
> | ~~~~~~~~~~~~~~~~~~~~~~
>>> drivers/net/wireless/intel/iwlwifi/mvm/d3.c:2149:2: error: call to '__compiletime_assert_1044' declared with 'error' attribute: BUILD_BUG_ON failed: conf->keylen < WLAN_KEY_LEN_GCMP_256
> 2149 | BUILD_BUG_ON(conf->keylen < WLAN_KEY_LEN_GCMP_256);
> | ^
> include/linux/build_bug.h:50:2: note: expanded from macro 'BUILD_BUG_ON'
> 50 | BUILD_BUG_ON_MSG(condition, "BUILD_BUG_ON failed: " #condition)
> | ^
> include/linux/build_bug.h:39:37: note: expanded from macro 'BUILD_BUG_ON_MSG'
> 39 | #define BUILD_BUG_ON_MSG(cond, msg) compiletime_assert(!(cond), msg)
> | ^
> include/linux/compiler_types.h:510:2: note: expanded from macro 'compiletime_assert'
> 510 | _compiletime_assert(condition, msg, __compiletime_assert_, __COUNTER__)
> | ^
> include/linux/compiler_types.h:498:2: note: expanded from macro '_compiletime_assert'
> 498 | __compiletime_assert(condition, msg, prefix, suffix)
> | ^
> include/linux/compiler_types.h:491:4: note: expanded from macro '__compiletime_assert'
> 491 | prefix ## suffix(); \
> | ^
> <scratch space>:38:1: note: expanded from here
> 38 | __compiletime_assert_1044
> | ^
>>> drivers/net/wireless/intel/iwlwifi/mvm/d3.c:2148:2: error: call to '__compiletime_assert_1043' declared with 'error' attribute: BUILD_BUG_ON failed: conf->keylen < WLAN_KEY_LEN_CCMP
> 2148 | BUILD_BUG_ON(conf->keylen < WLAN_KEY_LEN_CCMP);
> | ^
> include/linux/build_bug.h:50:2: note: expanded from macro 'BUILD_BUG_ON'
> 50 | BUILD_BUG_ON_MSG(condition, "BUILD_BUG_ON failed: " #condition)
> | ^
> include/linux/build_bug.h:39:37: note: expanded from macro 'BUILD_BUG_ON_MSG'
> 39 | #define BUILD_BUG_ON_MSG(cond, msg) compiletime_assert(!(cond), msg)
> | ^
> include/linux/compiler_types.h:510:2: note: expanded from macro 'compiletime_assert'
> 510 | _compiletime_assert(condition, msg, __compiletime_assert_, __COUNTER__)
> | ^
> include/linux/compiler_types.h:498:2: note: expanded from macro '_compiletime_assert'
> 498 | __compiletime_assert(condition, msg, prefix, suffix)
> | ^
> include/linux/compiler_types.h:491:4: note: expanded from macro '__compiletime_assert'
> 491 | prefix ## suffix(); \
> | ^
> <scratch space>:34:1: note: expanded from here
> 34 | __compiletime_assert_1043
> | ^
> 5 warnings and 2 errors generated.
>
>
> vim +2149 drivers/net/wireless/intel/iwlwifi/mvm/d3.c
>
> 2134
> 2135 static bool iwl_mvm_gtk_rekey(struct iwl_wowlan_status_data *status,
> 2136 struct ieee80211_vif *vif,
> 2137 struct iwl_mvm *mvm, u32 gtk_cipher)
> 2138 {
> 2139 int i, j;
> 2140 struct ieee80211_key_conf *key;
> 2141 DEFINE_FLEX(struct ieee80211_key_conf, conf, key, keylen,
> 2142 WOWLAN_KEY_MAX_SIZE);
> 2143 int link_id = vif->active_links ? __ffs(vif->active_links) : -1;

Holy molly guaca-guaca... swapping the above two lines fixes the issue:

diff --git a/drivers/net/wireless/intel/iwlwifi/mvm/d3.c b/drivers/net/wireless/intel/iwlwifi/mvm/d3.c
index 581455ab5e6d..764580cf6c58 100644
--- a/drivers/net/wireless/intel/iwlwifi/mvm/d3.c
+++ b/drivers/net/wireless/intel/iwlwifi/mvm/d3.c
@@ -2138,9 +2138,8 @@ static bool iwl_mvm_gtk_rekey(struct iwl_wowlan_status_data *status,
{
int i, j;
struct ieee80211_key_conf *key;
- DEFINE_FLEX(struct ieee80211_key_conf, conf, key, keylen,
- WOWLAN_KEY_MAX_SIZE);
int link_id = vif->active_links ? __ffs(vif->active_links) : -1;
+ DEFINE_FLEX(struct ieee80211_key_conf, conf, key, keylen, WOWLAN_KEY_MAX_SIZE);

conf->cipher = gtk_cipher;

This is the first time I've seen this compiler behavior when building DEFINE_FLEX() changes...

--
Gustavo

> 2144
> 2145 conf->cipher = gtk_cipher;
> 2146
> 2147 BUILD_BUG_ON(WLAN_KEY_LEN_CCMP != WLAN_KEY_LEN_GCMP);
>> 2148 BUILD_BUG_ON(conf->keylen < WLAN_KEY_LEN_CCMP);
>> 2149 BUILD_BUG_ON(conf->keylen < WLAN_KEY_LEN_GCMP_256);
> 2150 BUILD_BUG_ON(conf->keylen < WLAN_KEY_LEN_TKIP);
> 2151 BUILD_BUG_ON(conf->keylen < sizeof(status->gtk[0].key));
> 2152
> 2153 switch (gtk_cipher) {
> 2154 case WLAN_CIPHER_SUITE_CCMP:
> 2155 case WLAN_CIPHER_SUITE_GCMP:
> 2156 conf->keylen = WLAN_KEY_LEN_CCMP;
> 2157 break;
> 2158 case WLAN_CIPHER_SUITE_GCMP_256:
> 2159 conf->keylen = WLAN_KEY_LEN_GCMP_256;
> 2160 break;
> 2161 case WLAN_CIPHER_SUITE_TKIP:
> 2162 conf->keylen = WLAN_KEY_LEN_TKIP;
> 2163 break;
> 2164 default:
> 2165 WARN_ON(1);
> 2166 }
> 2167
> 2168 for (i = 0; i < ARRAY_SIZE(status->gtk); i++) {
> 2169 if (!status->gtk[i].len)
> 2170 continue;
> 2171
> 2172 conf->keyidx = status->gtk[i].id;
> 2173 IWL_DEBUG_WOWLAN(mvm,
> 2174 "Received from FW GTK cipher %d, key index %d\n",
> 2175 conf->cipher, conf->keyidx);
> 2176 memcpy(conf->key, status->gtk[i].key,
> 2177 sizeof(status->gtk[i].key));
> 2178
> 2179 key = ieee80211_gtk_rekey_add(vif, conf, link_id);
> 2180 if (IS_ERR(key))
> 2181 return false;
> 2182
> 2183 for (j = 0; j < ARRAY_SIZE(status->gtk_seq); j++) {
> 2184 if (!status->gtk_seq[j].valid ||
> 2185 status->gtk_seq[j].key_id != key->keyidx)
> 2186 continue;
> 2187 iwl_mvm_set_key_rx_seq_idx(key, status, j);
> 2188 break;
> 2189 }
> 2190 WARN_ON(j == ARRAY_SIZE(status->gtk_seq));
> 2191 }
> 2192
> 2193 return true;
> 2194 }
> 2195
>