Messages in this thread Patch in this message | | | From | Arnd Bergmann <> | Subject | [PATCH] [v3] iwlwifi: pcie: fix constant-conversion warning | Date | Thu, 18 Nov 2021 15:21:02 +0100 |
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From: Arnd Bergmann <arnd@arndb.de>
gcc-11 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 v3: - make it actually work with gcc-11 - fix commit message s/clang/gcc-11/
Changes in v2: - replace int cast with a range check --- drivers/net/wireless/intel/iwlwifi/pcie/drv.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-)
diff --git a/drivers/net/wireless/intel/iwlwifi/pcie/drv.c b/drivers/net/wireless/intel/iwlwifi/pcie/drv.c index c574f041f096..395e328c6a07 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 && -- 2.29.2
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