From: Arnd Bergmann Date: Thu, 18 Nov 2021 14:21:02 +0000 (+0100) Subject: iwlwifi: pcie: fix constant-conversion warning X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=fe785f56ad5886c08d1cadd9e8b4e1ff6a1866f6;p=linux.git iwlwifi: pcie: fix constant-conversion warning Both gcc-11 and clang point out a potential issue with integer overflow when the iwl_dev_info_table[] array is empty. This is what clang warns: 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 Cc: Nick Desaulniers Signed-off-by: Arnd Bergmann Reviewed-by: Nathan Chancellor Signed-off-by: Kalle Valo Link: https://lore.kernel.org/r/20211118142124.526901-1-arnd@kernel.org --- diff --git a/drivers/net/wireless/intel/iwlwifi/pcie/drv.c b/drivers/net/wireless/intel/iwlwifi/pcie/drv.c index c574f041f0969..395e328c6a07d 100644 --- a/drivers/net/wireless/intel/iwlwifi/pcie/drv.c +++ b/drivers/net/wireless/intel/iwlwifi/pcie/drv.c @@ -1339,9 +1339,13 @@ iwl_pci_find_dev_info(u16 device, u16 subsystem_device, u16 mac_type, u8 mac_step, u16 rf_type, u8 cdb, u8 rf_id, u8 no_160, u8 cores) { + int num_devices = ARRAY_SIZE(iwl_dev_info_table); int i; - for (i = ARRAY_SIZE(iwl_dev_info_table) - 1; i >= 0; i--) { + if (!num_devices) + return NULL; + + for (i = num_devices - 1; i >= 0; i--) { const struct iwl_dev_info *dev_info = &iwl_dev_info_table[i]; if (dev_info->device != (u16)IWL_CFG_ANY &&