| Message ID | 20211104133735.1223989-1-arnd@kernel.org (mailing list archive) |
|---|---|
| State | Superseded |
| Delegated to: | Luca Coelho |
| Headers | show |
| Series | iwlwifi: pcie: fix constant-conversion warning | expand |
On Thu, Nov 4, 2021 at 6:37 AM Arnd Bergmann <arnd@kernel.org> wrote: > > From: Arnd Bergmann <arnd@arndb.de> > > clang points out a potential issue with integer overflow when > the iwl_dev_info_table[] array is empty: > > drivers/net/wireless/intel/iwlwifi/pcie/drv.c:1344:42: error: implicit conversion from 'unsigned long' to 'int' changes value from 18446744073709551615 to -1 [-Werror,-Wconstant-conversion] > for (i = ARRAY_SIZE(iwl_dev_info_table) - 1; i >= 0; i--) { > ~ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~ > > This is still harmless, as the loop correctly terminates, but adding > an (int) cast makes that clearer to the compiler. > > Fixes: 3f7320428fa4 ("iwlwifi: pcie: simplify iwl_pci_find_dev_info()") > Signed-off-by: Arnd Bergmann <arnd@arndb.de> > --- > drivers/net/wireless/intel/iwlwifi/pcie/drv.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/net/wireless/intel/iwlwifi/pcie/drv.c b/drivers/net/wireless/intel/iwlwifi/pcie/drv.c > index c574f041f096..81e8f2fc4982 100644 > --- a/drivers/net/wireless/intel/iwlwifi/pcie/drv.c > +++ b/drivers/net/wireless/intel/iwlwifi/pcie/drv.c > @@ -1341,7 +1341,7 @@ iwl_pci_find_dev_info(u16 device, u16 subsystem_device, > { > int i; > > - for (i = ARRAY_SIZE(iwl_dev_info_table) - 1; i >= 0; i--) { > + for (i = (int)ARRAY_SIZE(iwl_dev_info_table) - 1; i >= 0; i--) { Perhaps `i` could be a `size_t` instead of an `int`? size_t i = ARRAY_SIZE(iwl_dev_info_table); while (i--) { ... > const struct iwl_dev_info *dev_info = &iwl_dev_info_table[i]; > > if (dev_info->device != (u16)IWL_CFG_ANY && > -- > 2.29.2 >
On Wed, Nov 10, 2021 at 1:38 PM Nick Desaulniers <ndesaulniers@google.com> wrote: > > On Thu, Nov 4, 2021 at 6:37 AM Arnd Bergmann <arnd@kernel.org> wrote: > > > > From: Arnd Bergmann <arnd@arndb.de> > > > > clang points out a potential issue with integer overflow when > > the iwl_dev_info_table[] array is empty: > > > > drivers/net/wireless/intel/iwlwifi/pcie/drv.c:1344:42: error: implicit conversion from 'unsigned long' to 'int' changes value from 18446744073709551615 to -1 [-Werror,-Wconstant-conversion] > > for (i = ARRAY_SIZE(iwl_dev_info_table) - 1; i >= 0; i--) { > > ~ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~ > > > > This is still harmless, as the loop correctly terminates, but adding > > an (int) cast makes that clearer to the compiler. > > > > Fixes: 3f7320428fa4 ("iwlwifi: pcie: simplify iwl_pci_find_dev_info()") > > Signed-off-by: Arnd Bergmann <arnd@arndb.de> Also, looks like 0day bot reported as well: https://lore.kernel.org/lkml/202111070825.gigxmmDq-lkp@intel.com/ Reported-by: kernel test robot <lkp@intel.com>
On Wed, Nov 10, 2021 at 10:38 PM Nick Desaulniers <ndesaulniers@google.com> wrote: > > On Thu, Nov 4, 2021 at 6:37 AM Arnd Bergmann <arnd@kernel.org> wrote: > > > > From: Arnd Bergmann <arnd@arndb.de> > > > > clang points out a potential issue with integer overflow when > > the iwl_dev_info_table[] array is empty: > > > > drivers/net/wireless/intel/iwlwifi/pcie/drv.c:1344:42: error: implicit conversion from 'unsigned long' to 'int' changes value from 18446744073709551615 to -1 [-Werror,-Wconstant-conversion] > > for (i = ARRAY_SIZE(iwl_dev_info_table) - 1; i >= 0; i--) { > > ~ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~ > > > > This is still harmless, as the loop correctly terminates, but adding > > an (int) cast makes that clearer to the compiler. > > > > Fixes: 3f7320428fa4 ("iwlwifi: pcie: simplify iwl_pci_find_dev_info()") > > Signed-off-by: Arnd Bergmann <arnd@arndb.de> > > --- > > drivers/net/wireless/intel/iwlwifi/pcie/drv.c | 2 +- > > 1 file changed, 1 insertion(+), 1 deletion(-) > > > > diff --git a/drivers/net/wireless/intel/iwlwifi/pcie/drv.c b/drivers/net/wireless/intel/iwlwifi/pcie/drv.c > > index c574f041f096..81e8f2fc4982 100644 > > --- a/drivers/net/wireless/intel/iwlwifi/pcie/drv.c > > +++ b/drivers/net/wireless/intel/iwlwifi/pcie/drv.c > > @@ -1341,7 +1341,7 @@ iwl_pci_find_dev_info(u16 device, u16 subsystem_device, > > { > > int i; > > > > - for (i = ARRAY_SIZE(iwl_dev_info_table) - 1; i >= 0; i--) { > > + for (i = (int)ARRAY_SIZE(iwl_dev_info_table) - 1; i >= 0; i--) { > > Perhaps `i` could be a `size_t` instead of an `int`? > > size_t i = ARRAY_SIZE(iwl_dev_info_table); > while (i--) { > ... I imagine 'i' is idiomatically 'int' in inner iterations. I've sent a different fix now. Arnd
diff --git a/drivers/net/wireless/intel/iwlwifi/pcie/drv.c b/drivers/net/wireless/intel/iwlwifi/pcie/drv.c index c574f041f096..81e8f2fc4982 100644 --- a/drivers/net/wireless/intel/iwlwifi/pcie/drv.c +++ b/drivers/net/wireless/intel/iwlwifi/pcie/drv.c @@ -1341,7 +1341,7 @@ iwl_pci_find_dev_info(u16 device, u16 subsystem_device, { int i; - for (i = ARRAY_SIZE(iwl_dev_info_table) - 1; i >= 0; i--) { + for (i = (int)ARRAY_SIZE(iwl_dev_info_table) - 1; i >= 0; i--) { const struct iwl_dev_info *dev_info = &iwl_dev_info_table[i]; if (dev_info->device != (u16)IWL_CFG_ANY &&