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[PATCH] iwlwifi: mvm: fix clang -Wformat warnings

Justin Stitt posted 1 patch 3 years, 9 months ago 
drivers/net/wireless/intel/iwlwifi/mvm/ftm-initiator.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
[PATCH] iwlwifi: mvm: fix clang -Wformat warnings
Posted by Justin Stitt 3 years, 9 months ago 
When building with Clang we encounter these warnings:
| drivers/net/wireless/intel/iwlwifi/mvm/ftm-initiator.c:1108:47: error:
| format specifies type 'unsigned char' but the argument has type 's16'
| (aka 'short') [-Werror,-Wformat] IWL_DEBUG_INFO(mvm, "\tburst index:
| %hhu\n", res->ftm.burst_index);
-
| drivers/net/wireless/intel/iwlwifi/mvm/ftm-initiator.c:1111:47: error:
| format specifies type 'unsigned char' but the argument has type 's32'
| (aka 'int') [-Werror,-Wformat] IWL_DEBUG_INFO(mvm, "\trssi spread:
| %hhu\n", res->ftm.rssi_spread);

The previous format specifier `%hhu` describes a u8 but our arguments
are wider than this which means bits are potentially being lost.

Variadic functions (printf-like) undergo default argument promotion.
Documentation/core-api/printk-formats.rst specifically recommends using
the promoted-to-type's format flag.

As per C11 6.3.1.1:
(https://www.open-std.org/jtc1/sc22/wg14/www/docs/n1548.pdf) `If an int
can represent all values of the original type ..., the value is
converted to an int; otherwise, it is converted to an unsigned int.
These are called the integer promotions.` Thus it makes sense to change
`%hhu` to `%d` for both instances of the warning.

Link: https://github.com/ClangBuiltLinux/linux/issues/378
Signed-off-by: Justin Stitt <justinstitt@google.com>
---
 drivers/net/wireless/intel/iwlwifi/mvm/ftm-initiator.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/net/wireless/intel/iwlwifi/mvm/ftm-initiator.c b/drivers/net/wireless/intel/iwlwifi/mvm/ftm-initiator.c
index 430044bc4755..e8702184c950 100644
--- a/drivers/net/wireless/intel/iwlwifi/mvm/ftm-initiator.c
+++ b/drivers/net/wireless/intel/iwlwifi/mvm/ftm-initiator.c
@@ -1105,10 +1105,10 @@ static void iwl_mvm_debug_range_resp(struct iwl_mvm *mvm, u8 index,
 	IWL_DEBUG_INFO(mvm, "\tstatus: %d\n", res->status);
 	IWL_DEBUG_INFO(mvm, "\tBSSID: %pM\n", res->addr);
 	IWL_DEBUG_INFO(mvm, "\thost time: %llu\n", res->host_time);
-	IWL_DEBUG_INFO(mvm, "\tburst index: %hhu\n", res->ftm.burst_index);
+	IWL_DEBUG_INFO(mvm, "\tburst index: %d\n", res->ftm.burst_index);
 	IWL_DEBUG_INFO(mvm, "\tsuccess num: %u\n", res->ftm.num_ftmr_successes);
 	IWL_DEBUG_INFO(mvm, "\trssi: %d\n", res->ftm.rssi_avg);
-	IWL_DEBUG_INFO(mvm, "\trssi spread: %hhu\n", res->ftm.rssi_spread);
+	IWL_DEBUG_INFO(mvm, "\trssi spread: %d\n", res->ftm.rssi_spread);
 	IWL_DEBUG_INFO(mvm, "\trtt: %lld\n", res->ftm.rtt_avg);
 	IWL_DEBUG_INFO(mvm, "\trtt var: %llu\n", res->ftm.rtt_variance);
 	IWL_DEBUG_INFO(mvm, "\trtt spread: %llu\n", res->ftm.rtt_spread);
-- 
2.37.0.144.g8ac04bfd2-goog
Re: wifi: iwlwifi: mvm: fix clang -Wformat warnings
Posted by Kalle Valo 3 years, 8 months ago 
Justin Stitt <justinstitt@google.com> wrote:

> When building with Clang we encounter these warnings:
> | drivers/net/wireless/intel/iwlwifi/mvm/ftm-initiator.c:1108:47: error:
> | format specifies type 'unsigned char' but the argument has type 's16'
> | (aka 'short') [-Werror,-Wformat] IWL_DEBUG_INFO(mvm, "\tburst index:
> | %hhu\n", res->ftm.burst_index);
> -
> | drivers/net/wireless/intel/iwlwifi/mvm/ftm-initiator.c:1111:47: error:
> | format specifies type 'unsigned char' but the argument has type 's32'
> | (aka 'int') [-Werror,-Wformat] IWL_DEBUG_INFO(mvm, "\trssi spread:
> | %hhu\n", res->ftm.rssi_spread);
> 
> The previous format specifier `%hhu` describes a u8 but our arguments
> are wider than this which means bits are potentially being lost.
> 
> Variadic functions (printf-like) undergo default argument promotion.
> Documentation/core-api/printk-formats.rst specifically recommends using
> the promoted-to-type's format flag.
> 
> As per C11 6.3.1.1:
> (https://www.open-std.org/jtc1/sc22/wg14/www/docs/n1548.pdf) `If an int
> can represent all values of the original type ..., the value is
> converted to an int; otherwise, it is converted to an unsigned int.
> These are called the integer promotions.` Thus it makes sense to change
> `%hhu` to `%d` for both instances of the warning.
> 
> Link: https://github.com/ClangBuiltLinux/linux/issues/378
> Signed-off-by: Justin Stitt <justinstitt@google.com>
> Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>

Patch applied to wireless-next.git, thanks.

7819b3d1dab5 wifi: iwlwifi: mvm: fix clang -Wformat warnings

-- 
https://patchwork.kernel.org/project/linux-wireless/patch/20220711222919.2043613-1-justinstitt@google.com/

https://wireless.wiki.kernel.org/en/developers/documentation/submittingpatches
Re: [PATCH] iwlwifi: mvm: fix clang -Wformat warnings
Posted by Nick Desaulniers 3 years, 9 months ago 
On Mon, Jul 11, 2022 at 3:29 PM Justin Stitt <justinstitt@google.com> wrote:
>
> When building with Clang we encounter these warnings:
> | drivers/net/wireless/intel/iwlwifi/mvm/ftm-initiator.c:1108:47: error:
> | format specifies type 'unsigned char' but the argument has type 's16'
> | (aka 'short') [-Werror,-Wformat] IWL_DEBUG_INFO(mvm, "\tburst index:
> | %hhu\n", res->ftm.burst_index);
> -
> | drivers/net/wireless/intel/iwlwifi/mvm/ftm-initiator.c:1111:47: error:
> | format specifies type 'unsigned char' but the argument has type 's32'
> | (aka 'int') [-Werror,-Wformat] IWL_DEBUG_INFO(mvm, "\trssi spread:
> | %hhu\n", res->ftm.rssi_spread);
>
> The previous format specifier `%hhu` describes a u8 but our arguments
> are wider than this which means bits are potentially being lost.
>
> Variadic functions (printf-like) undergo default argument promotion.
> Documentation/core-api/printk-formats.rst specifically recommends using
> the promoted-to-type's format flag.
>
> As per C11 6.3.1.1:
> (https://www.open-std.org/jtc1/sc22/wg14/www/docs/n1548.pdf) `If an int
> can represent all values of the original type ..., the value is
> converted to an int; otherwise, it is converted to an unsigned int.
> These are called the integer promotions.` Thus it makes sense to change
> `%hhu` to `%d` for both instances of the warning.
>
> Link: https://github.com/ClangBuiltLinux/linux/issues/378
> Signed-off-by: Justin Stitt <justinstitt@google.com>

Thanks for the patch!
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>

> ---
>  drivers/net/wireless/intel/iwlwifi/mvm/ftm-initiator.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/net/wireless/intel/iwlwifi/mvm/ftm-initiator.c b/drivers/net/wireless/intel/iwlwifi/mvm/ftm-initiator.c
> index 430044bc4755..e8702184c950 100644
> --- a/drivers/net/wireless/intel/iwlwifi/mvm/ftm-initiator.c
> +++ b/drivers/net/wireless/intel/iwlwifi/mvm/ftm-initiator.c
> @@ -1105,10 +1105,10 @@ static void iwl_mvm_debug_range_resp(struct iwl_mvm *mvm, u8 index,
>         IWL_DEBUG_INFO(mvm, "\tstatus: %d\n", res->status);
>         IWL_DEBUG_INFO(mvm, "\tBSSID: %pM\n", res->addr);
>         IWL_DEBUG_INFO(mvm, "\thost time: %llu\n", res->host_time);
> -       IWL_DEBUG_INFO(mvm, "\tburst index: %hhu\n", res->ftm.burst_index);
> +       IWL_DEBUG_INFO(mvm, "\tburst index: %d\n", res->ftm.burst_index);
>         IWL_DEBUG_INFO(mvm, "\tsuccess num: %u\n", res->ftm.num_ftmr_successes);
>         IWL_DEBUG_INFO(mvm, "\trssi: %d\n", res->ftm.rssi_avg);
> -       IWL_DEBUG_INFO(mvm, "\trssi spread: %hhu\n", res->ftm.rssi_spread);
> +       IWL_DEBUG_INFO(mvm, "\trssi spread: %d\n", res->ftm.rssi_spread);
>         IWL_DEBUG_INFO(mvm, "\trtt: %lld\n", res->ftm.rtt_avg);
>         IWL_DEBUG_INFO(mvm, "\trtt var: %llu\n", res->ftm.rtt_variance);
>         IWL_DEBUG_INFO(mvm, "\trtt spread: %llu\n", res->ftm.rtt_spread);
> --
> 2.37.0.144.g8ac04bfd2-goog
>


-- 
Thanks,
~Nick Desaulniers
Re: [PATCH] iwlwifi: mvm: fix clang -Wformat warnings
Posted by Justin Stitt 3 years, 9 months ago 
Any chance a maintainer could take a look at this patch? I am trying
to get it through this cycle and we are so close to enabling the
-Wformat option for Clang. There's only a handful of patches remaining
until the patch enabling this warning can be sent!
Re: [PATCH] iwlwifi: mvm: fix clang -Wformat warnings
Posted by Kalle Valo 3 years, 8 months ago 
Justin Stitt <justinstitt@google.com> writes:

> Any chance a maintainer could take a look at this patch? I am trying
> to get it through this cycle and we are so close to enabling the
> -Wformat option for Clang. There's only a handful of patches remaining
> until the patch enabling this warning can be sent!

Gregory, can I take this directly to wireless-next? I assigned it to me
in patchwork.

-- 
https://patchwork.kernel.org/project/linux-wireless/list/

https://wireless.wiki.kernel.org/en/developers/documentation/submittingpatches
Re: [PATCH] iwlwifi: mvm: fix clang -Wformat warnings
Posted by Greenman, Gregory 3 years, 8 months ago 
On Tue, 2022-07-26 at 17:27 +0300, Kalle Valo wrote:
> Justin Stitt <justinstitt@google.com> writes:
> 
> > Any chance a maintainer could take a look at this patch? I am trying
> > to get it through this cycle and we are so close to enabling the
> > -Wformat option for Clang. There's only a handful of patches remaining
> > until the patch enabling this warning can be sent!
> 
> Gregory, can I take this directly to wireless-next? I assigned it to me
> in patchwork.
> 
Sorry for the long delay. Yes, it looks like a good fix. Thanks!

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