| Message ID | 20190322141322.463149-1-arnd@arndb.de |
|---|---|
| State | New |
| Headers | show |
| Series | iwlwifi: work around clang -Wuninitialized warning | expand |
On Fri, 2019-03-22 at 15:13 +0100, Arnd Bergmann wrote: > Clang incorrectly warns about an uninitialized variable: > > drivers/net/wireless/intel/iwlwifi/mvm/sta.c:2114:12: error: variable > 'queue' is used uninitialized whenever 'if' > condition is false [-Werror,-Wsometimes-uninitialized] > else if (WARN(1, "Missing required TXQ for adding > bcast STA\n")) > ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ > ~~~~~~~~~~ > include/asm-generic/bug.h:130:36: note: expanded from macro 'WARN' > #define WARN(condition, format...) > ({ \ > ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ > ~~~~ > drivers/net/wireless/intel/iwlwifi/mvm/sta.c:2119:33: note: > uninitialized use occurs here > iwl_mvm_enable_txq(mvm, NULL, queue, 0, &cfg, > wdg_timeout); > ^~~~~ > drivers/net/wireless/intel/iwlwifi/mvm/sta.c:2114:8: note: remove the > 'if' if its condition is always true > else if (WARN(1, "Missing required TXQ for adding > bcast STA\n")) > ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ > ~~~~~~~~~~~ > drivers/net/wireless/intel/iwlwifi/mvm/sta.c:2094:11: note: > initialize the variable 'queue' to silence this warning > int queue; > ^ > = 0 > 1 error generated. > > This cannot happen because the if/else if/else if block always > has one code path that is entered. However, we can simply > rearrange the code to let clang see this as well. > > Signed-off-by: Arnd Bergmann <arnd@arndb.de> > --- Thanks for the patch, Arnd! But I have already queued up an equivalent patch for v5.2 (should probably reach linux-next by the end of next week or so): https://patchwork.kernel.org/patch/10844025/ -- Cheers, Luca.
On Sat, Mar 23, 2019 at 7:11 AM Luca Coelho <luca@coelho.fi> wrote: > > On Fri, 2019-03-22 at 15:13 +0100, Arnd Bergmann wrote: > > Clang incorrectly warns about an uninitialized variable: > > > > > > This cannot happen because the if/else if/else if block always > > has one code path that is entered. However, we can simply > > rearrange the code to let clang see this as well. > > > > Signed-off-by: Arnd Bergmann <arnd@arndb.de> > > --- > > Thanks for the patch, Arnd! But I have already queued up an equivalent > patch for v5.2 (should probably reach linux-next by the end of next > week or so): > > https://patchwork.kernel.org/patch/10844025/ Thanks, and sorry for the duplicate. I forgot to check for the patches that Nathan had already done when I started sending out my own series on the same issues. Arnd
diff --git a/drivers/net/wireless/intel/iwlwifi/mvm/sta.c b/drivers/net/wireless/intel/iwlwifi/mvm/sta.c index 498c315291cf..91ce56d2ebb8 100644 --- a/drivers/net/wireless/intel/iwlwifi/mvm/sta.c +++ b/drivers/net/wireless/intel/iwlwifi/mvm/sta.c @@ -2107,12 +2107,14 @@ int iwl_mvm_send_add_bcast_sta(struct iwl_mvm *mvm, struct ieee80211_vif *vif) if (!iwl_mvm_has_new_tx_api(mvm)) { if (vif->type == NL80211_IFTYPE_AP || - vif->type == NL80211_IFTYPE_ADHOC) + vif->type == NL80211_IFTYPE_ADHOC) { queue = mvm->probe_queue; - else if (vif->type == NL80211_IFTYPE_P2P_DEVICE) + } else if (vif->type == NL80211_IFTYPE_P2P_DEVICE) { queue = mvm->p2p_dev_queue; - else if (WARN(1, "Missing required TXQ for adding bcast STA\n")) + } else { + WARN(1, "Missing required TXQ for adding bcast STA\n"); return -EINVAL; + } bsta->tfd_queue_msk |= BIT(queue);
Clang incorrectly warns about an uninitialized variable: drivers/net/wireless/intel/iwlwifi/mvm/sta.c:2114:12: error: variable 'queue' is used uninitialized whenever 'if' condition is false [-Werror,-Wsometimes-uninitialized] else if (WARN(1, "Missing required TXQ for adding bcast STA\n")) ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ include/asm-generic/bug.h:130:36: note: expanded from macro 'WARN' #define WARN(condition, format...) ({ \ ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ drivers/net/wireless/intel/iwlwifi/mvm/sta.c:2119:33: note: uninitialized use occurs here iwl_mvm_enable_txq(mvm, NULL, queue, 0, &cfg, wdg_timeout); ^~~~~ drivers/net/wireless/intel/iwlwifi/mvm/sta.c:2114:8: note: remove the 'if' if its condition is always true else if (WARN(1, "Missing required TXQ for adding bcast STA\n")) ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ drivers/net/wireless/intel/iwlwifi/mvm/sta.c:2094:11: note: initialize the variable 'queue' to silence this warning int queue; ^ = 0 1 error generated. This cannot happen because the if/else if/else if block always has one code path that is entered. However, we can simply rearrange the code to let clang see this as well. Signed-off-by: Arnd Bergmann <arnd@arndb.de> --- drivers/net/wireless/intel/iwlwifi/mvm/sta.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) -- 2.20.0