| Message ID | 20211111073145.2504032-1-arnd@kernel.org (mailing list archive) |
|---|---|
| State | Changes Requested |
| Delegated to: | Kalle Valo |
| Headers | show |
| Series | [v2] iwlwifi: pcie: fix constant-conversion warning | expand |
On Thu, 2021-11-11 at 08:31 +0100, Arnd Bergmann 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 extra range check makes that obvious to both readers and to the > compiler. > > Fixes: 3f7320428fa4 ("iwlwifi: pcie: simplify iwl_pci_find_dev_info()") > Reported-by: kernel test robot <lkp@intel.com> > Cc: Nick Desaulniers <ndesaulniers@google.com> > Signed-off-by: Arnd Bergmann <arnd@arndb.de> > --- > Changes in v2: > - replace int cast with a range check > --- > drivers/net/wireless/intel/iwlwifi/pcie/drv.c | 3 +++ > 1 file changed, 3 insertions(+) > > diff --git a/drivers/net/wireless/intel/iwlwifi/pcie/drv.c b/drivers/net/wireless/intel/iwlwifi/pcie/drv.c > index c574f041f096..fcda7603024b 100644 > --- a/drivers/net/wireless/intel/iwlwifi/pcie/drv.c > +++ b/drivers/net/wireless/intel/iwlwifi/pcie/drv.c > @@ -1341,6 +1341,9 @@ iwl_pci_find_dev_info(u16 device, u16 subsystem_device, > { > int i; > > + if (ARRAY_SIZE(iwl_dev_info_table) == 0) > + return NULL; > + > for (i = ARRAY_SIZE(iwl_dev_info_table) - 1; i >= 0; i--) { > const struct iwl_dev_info *dev_info = &iwl_dev_info_table[i]; This looks good now. Acked-by: Luca Coelho <luciano.coelho@intel.com> Kalle, I'll assign it to you so you can take it to wireless-drivers when it opens again. Thanks! -- Cheers, Luca.
On Thu, Nov 11, 2021 at 8:31 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 extra range check makes that obvious to both readers and to the > compiler. > > Fixes: 3f7320428fa4 ("iwlwifi: pcie: simplify iwl_pci_find_dev_info()") > Reported-by: kernel test robot <lkp@intel.com> > Cc: Nick Desaulniers <ndesaulniers@google.com> > Signed-off-by: Arnd Bergmann <arnd@arndb.de> Something went wrong on my end: I thought this was a clang warning and that I had fixed it because it didn't come back with my v2 patch. However I now see it in my gcc-11 test builds, so I assume this was a gcc warning all along, and that my patch does nothing. Please disregard it if you have not already applied it. Arnd
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 extra range check makes that obvious to both readers and to the > compiler. > > Fixes: 3f7320428fa4 ("iwlwifi: pcie: simplify iwl_pci_find_dev_info()") > Reported-by: kernel test robot <lkp@intel.com> > Cc: Nick Desaulniers <ndesaulniers@google.com> > Signed-off-by: Arnd Bergmann <arnd@arndb.de> > Acked-by: Luca Coelho <luciano.coelho@intel.com> Dropping v2 and taking v3 instead. Patch set to Changes Requested.
diff --git a/drivers/net/wireless/intel/iwlwifi/pcie/drv.c b/drivers/net/wireless/intel/iwlwifi/pcie/drv.c index c574f041f096..fcda7603024b 100644 --- a/drivers/net/wireless/intel/iwlwifi/pcie/drv.c +++ b/drivers/net/wireless/intel/iwlwifi/pcie/drv.c @@ -1341,6 +1341,9 @@ iwl_pci_find_dev_info(u16 device, u16 subsystem_device, { int i; + if (ARRAY_SIZE(iwl_dev_info_table) == 0) + return NULL; + for (i = ARRAY_SIZE(iwl_dev_info_table) - 1; i >= 0; i--) { const struct iwl_dev_info *dev_info = &iwl_dev_info_table[i];