* Re: [PATCH] [v2] iwlwifi: pcie: fix constant-conversion warning
2021-11-11 7:31 [PATCH] [v2] iwlwifi: pcie: fix constant-conversion warning Arnd Bergmann
@ 2021-11-12 9:17 ` Coelho, Luciano
2021-11-18 12:28 ` Arnd Bergmann
2021-11-22 18:30 ` Kalle Valo
2 siblings, 0 replies; 4+ messages in thread
From: Coelho, Luciano @ 2021-11-12 9:17 UTC (permalink / raw)
To: nathan@kernel.org, Berg, Johannes, arnd@kernel.org,
kvalo@codeaurora.org, davem@davemloft.net,
ndesaulniers@google.com, kuba@kernel.org
Cc: lkp, Baruch, Yaara, llvm@lists.linux.dev,
linux-kernel@vger.kernel.org, linux-wireless@vger.kernel.org,
netdev@vger.kernel.org, Gottlieb, Matti, arnd@arndb.de,
Grumbach, Emmanuel
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.
^ permalink raw reply [flat|nested] 4+ messages in thread* Re: [PATCH] [v2] iwlwifi: pcie: fix constant-conversion warning
2021-11-11 7:31 [PATCH] [v2] iwlwifi: pcie: fix constant-conversion warning Arnd Bergmann
2021-11-12 9:17 ` Coelho, Luciano
@ 2021-11-18 12:28 ` Arnd Bergmann
2021-11-22 18:30 ` Kalle Valo
2 siblings, 0 replies; 4+ messages in thread
From: Arnd Bergmann @ 2021-11-18 12:28 UTC (permalink / raw)
To: Luca Coelho, Kalle Valo, David S. Miller, Jakub Kicinski,
Nathan Chancellor, Nick Desaulniers, Johannes Berg
Cc: Arnd Bergmann, kernel test robot, Yaara Baruch, Matti Gottlieb,
Emmanuel Grumbach, linux-wireless, Networking,
Linux Kernel Mailing List, llvm
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
^ permalink raw reply [flat|nested] 4+ messages in thread* Re: [PATCH] [v2] iwlwifi: pcie: fix constant-conversion warning
2021-11-11 7:31 [PATCH] [v2] iwlwifi: pcie: fix constant-conversion warning Arnd Bergmann
2021-11-12 9:17 ` Coelho, Luciano
2021-11-18 12:28 ` Arnd Bergmann
@ 2021-11-22 18:30 ` Kalle Valo
2 siblings, 0 replies; 4+ messages in thread
From: Kalle Valo @ 2021-11-22 18:30 UTC (permalink / raw)
To: Arnd Bergmann
Cc: Luca Coelho, David S. Miller, Jakub Kicinski, Nathan Chancellor,
Nick Desaulniers, Johannes Berg, Arnd Bergmann, kernel test robot,
Yaara Baruch, Matti Gottlieb, Emmanuel Grumbach, linux-wireless,
netdev, linux-kernel, llvm
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.
--
https://patchwork.kernel.org/project/linux-wireless/patch/20211111073145.2504032-1-arnd@kernel.org/
https://wireless.wiki.kernel.org/en/developers/documentation/submittingpatches
^ permalink raw reply [flat|nested] 4+ messages in thread