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* [PATCH] iwlwifi: pcie: fix constant-conversion warning
@ 2021-10-29 15:42 Arnd Bergmann
  2021-10-31  7:06 ` Kalle Valo
  0 siblings, 1 reply; 8+ messages in thread
From: Arnd Bergmann @ 2021-10-29 15:42 UTC (permalink / raw)
  To: Johannes Berg
  Cc: Arnd Bergmann, Luca Coelho, Kalle Valo, David S. Miller,
	Jakub Kicinski, Nathan Chancellor, Nick Desaulniers,
	Yaara Baruch, Matti Gottlieb, Emmanuel Grumbach, linux-wireless,
	netdev, linux-kernel, llvm

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 (int) cast makes that clearer to the compiler.

Fixes: 3f7320428fa4 ("iwlwifi: pcie: simplify iwl_pci_find_dev_info()")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
 drivers/net/wireless/intel/iwlwifi/pcie/drv.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/wireless/intel/iwlwifi/pcie/drv.c b/drivers/net/wireless/intel/iwlwifi/pcie/drv.c
index c574f041f096..81e8f2fc4982 100644
--- a/drivers/net/wireless/intel/iwlwifi/pcie/drv.c
+++ b/drivers/net/wireless/intel/iwlwifi/pcie/drv.c
@@ -1341,7 +1341,7 @@ iwl_pci_find_dev_info(u16 device, u16 subsystem_device,
 {
 	int i;
 
-	for (i = ARRAY_SIZE(iwl_dev_info_table) - 1; i >= 0; i--) {
+	for (i = (int)ARRAY_SIZE(iwl_dev_info_table) - 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


^ permalink raw reply related	[flat|nested] 8+ messages in thread

* Re: [PATCH] iwlwifi: pcie: fix constant-conversion warning
  2021-10-29 15:42 [PATCH] iwlwifi: pcie: fix constant-conversion warning Arnd Bergmann
@ 2021-10-31  7:06 ` Kalle Valo
  2021-11-01  7:29   ` Coelho, Luciano
  0 siblings, 1 reply; 8+ messages in thread
From: Kalle Valo @ 2021-10-31  7:06 UTC (permalink / raw)
  To: Arnd Bergmann
  Cc: Johannes Berg, Arnd Bergmann, Luca Coelho, David S. Miller,
	Jakub Kicinski, Nathan Chancellor, Nick Desaulniers,
	Yaara Baruch, Matti Gottlieb, Emmanuel Grumbach, linux-wireless,
	netdev, linux-kernel, llvm

Arnd Bergmann <arnd@kernel.org> writes:

> 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 (int) cast makes that clearer to the compiler.
>
> Fixes: 3f7320428fa4 ("iwlwifi: pcie: simplify iwl_pci_find_dev_info()")
> Signed-off-by: Arnd Bergmann <arnd@arndb.de>

Luca, can I take this to wireless-drivers? Ack?

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

https://wireless.wiki.kernel.org/en/developers/documentation/submittingpatches

^ permalink raw reply	[flat|nested] 8+ messages in thread

* Re: [PATCH] iwlwifi: pcie: fix constant-conversion warning
  2021-10-31  7:06 ` Kalle Valo
@ 2021-11-01  7:29   ` Coelho, Luciano
  2021-11-01  7:32     ` Coelho, Luciano
  0 siblings, 1 reply; 8+ messages in thread
From: Coelho, Luciano @ 2021-11-01  7:29 UTC (permalink / raw)
  To: arnd, kvalo
  Cc: davem, Berg, Johannes, Baruch, Yaara, llvm, linux-wireless,
	nathan, kuba, Gottlieb, Matti, ndesaulniers, Grumbach, Emmanuel,
	linux-kernel, arnd, netdev

On Sun, 2021-10-31 at 09:06 +0200, Kalle Valo wrote:
> Arnd Bergmann <arnd@kernel.org> writes:
> 
> > 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 (int) cast makes that clearer to the compiler.
> > 
> > Fixes: 3f7320428fa4 ("iwlwifi: pcie: simplify iwl_pci_find_dev_info()")
> > Signed-off-by: Arnd Bergmann <arnd@arndb.de>
> 
> Luca, can I take this to wireless-drivers? Ack?

Yes, please do.

Thanks.

Acked-by: Luca Coelho <luciano.coelho@intel.com>

--
Cheers,
Luca.

^ permalink raw reply	[flat|nested] 8+ messages in thread

* Re: [PATCH] iwlwifi: pcie: fix constant-conversion warning
  2021-11-01  7:29   ` Coelho, Luciano
@ 2021-11-01  7:32     ` Coelho, Luciano
  0 siblings, 0 replies; 8+ messages in thread
From: Coelho, Luciano @ 2021-11-01  7:32 UTC (permalink / raw)
  To: arnd, kvalo
  Cc: davem, Berg, Johannes, Baruch, Yaara, llvm, linux-wireless,
	nathan, kuba, Gottlieb, Matti, ndesaulniers, Grumbach, Emmanuel,
	linux-kernel, arnd, netdev

On Mon, 2021-11-01 at 09:29 +0200, Luciano Coelho wrote:
> On Sun, 2021-10-31 at 09:06 +0200, Kalle Valo wrote:
> > Arnd Bergmann <arnd@kernel.org> writes:
> > 
> > > 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 (int) cast makes that clearer to the compiler.
> > > 
> > > Fixes: 3f7320428fa4 ("iwlwifi: pcie: simplify iwl_pci_find_dev_info()")
> > > Signed-off-by: Arnd Bergmann <arnd@arndb.de>
> > 
> > Luca, can I take this to wireless-drivers? Ack?
> 
> Yes, please do.
> 
> Thanks.
> 
> Acked-by: Luca Coelho <luciano.coelho@intel.com>

Actually, wouldn't it be simpler to change the declaration of i to be
unsigned int?

--
Luca.



^ permalink raw reply	[flat|nested] 8+ messages in thread

* Re: [PATCH] iwlwifi: pcie: fix constant-conversion warning
  2021-11-10 21:38 ` Nick Desaulniers
  2021-11-10 21:39   ` Nick Desaulniers
@ 2021-11-11  7:33   ` Arnd Bergmann
  1 sibling, 0 replies; 8+ messages in thread
From: Arnd Bergmann @ 2021-11-11  7:33 UTC (permalink / raw)
  To: Nick Desaulniers
  Cc: Luca Coelho, Kalle Valo, David S. Miller, Jakub Kicinski,
	Johannes Berg, Arnd Bergmann, Nathan Chancellor, Yaara Baruch,
	Matti Gottlieb, Emmanuel Grumbach, linux-wireless, Networking,
	Linux Kernel Mailing List, llvm

On Wed, Nov 10, 2021 at 10:38 PM Nick Desaulniers
<ndesaulniers@google.com> wrote:
>
> On Thu, Nov 4, 2021 at 6:37 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 (int) cast makes that clearer to the compiler.
> >
> > Fixes: 3f7320428fa4 ("iwlwifi: pcie: simplify iwl_pci_find_dev_info()")
> > Signed-off-by: Arnd Bergmann <arnd@arndb.de>
> > ---
> >  drivers/net/wireless/intel/iwlwifi/pcie/drv.c | 2 +-
> >  1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/drivers/net/wireless/intel/iwlwifi/pcie/drv.c b/drivers/net/wireless/intel/iwlwifi/pcie/drv.c
> > index c574f041f096..81e8f2fc4982 100644
> > --- a/drivers/net/wireless/intel/iwlwifi/pcie/drv.c
> > +++ b/drivers/net/wireless/intel/iwlwifi/pcie/drv.c
> > @@ -1341,7 +1341,7 @@ iwl_pci_find_dev_info(u16 device, u16 subsystem_device,
> >  {
> >         int i;
> >
> > -       for (i = ARRAY_SIZE(iwl_dev_info_table) - 1; i >= 0; i--) {
> > +       for (i = (int)ARRAY_SIZE(iwl_dev_info_table) - 1; i >= 0; i--) {
>
> Perhaps `i` could be a `size_t` instead of an `int`?
>
> size_t i = ARRAY_SIZE(iwl_dev_info_table);
> while (i--) {
>   ...

I imagine 'i' is idiomatically 'int' in inner iterations.

I've sent a different fix now.

        Arnd

^ permalink raw reply	[flat|nested] 8+ messages in thread

* Re: [PATCH] iwlwifi: pcie: fix constant-conversion warning
  2021-11-10 21:38 ` Nick Desaulniers
@ 2021-11-10 21:39   ` Nick Desaulniers
  2021-11-11  7:33   ` Arnd Bergmann
  1 sibling, 0 replies; 8+ messages in thread
From: Nick Desaulniers @ 2021-11-10 21:39 UTC (permalink / raw)
  To: Arnd Bergmann
  Cc: Luca Coelho, Kalle Valo, David S. Miller, Jakub Kicinski,
	Johannes Berg, Arnd Bergmann, Nathan Chancellor, Yaara Baruch,
	Matti Gottlieb, Emmanuel Grumbach, linux-wireless, netdev,
	linux-kernel, llvm

On Wed, Nov 10, 2021 at 1:38 PM Nick Desaulniers
<ndesaulniers@google.com> wrote:
>
> On Thu, Nov 4, 2021 at 6:37 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 (int) cast makes that clearer to the compiler.
> >
> > Fixes: 3f7320428fa4 ("iwlwifi: pcie: simplify iwl_pci_find_dev_info()")
> > Signed-off-by: Arnd Bergmann <arnd@arndb.de>

Also, looks like 0day bot reported as well:
https://lore.kernel.org/lkml/202111070825.gigxmmDq-lkp@intel.com/

Reported-by: kernel test robot <lkp@intel.com>


-- 
Thanks,
~Nick Desaulniers

^ permalink raw reply	[flat|nested] 8+ messages in thread

* Re: [PATCH] iwlwifi: pcie: fix constant-conversion warning
  2021-11-04 13:37 Arnd Bergmann
@ 2021-11-10 21:38 ` Nick Desaulniers
  2021-11-10 21:39   ` Nick Desaulniers
  2021-11-11  7:33   ` Arnd Bergmann
  0 siblings, 2 replies; 8+ messages in thread
From: Nick Desaulniers @ 2021-11-10 21:38 UTC (permalink / raw)
  To: Arnd Bergmann
  Cc: Luca Coelho, Kalle Valo, David S. Miller, Jakub Kicinski,
	Johannes Berg, Arnd Bergmann, Nathan Chancellor, Yaara Baruch,
	Matti Gottlieb, Emmanuel Grumbach, linux-wireless, netdev,
	linux-kernel, llvm

On Thu, Nov 4, 2021 at 6:37 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 (int) cast makes that clearer to the compiler.
>
> Fixes: 3f7320428fa4 ("iwlwifi: pcie: simplify iwl_pci_find_dev_info()")
> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
> ---
>  drivers/net/wireless/intel/iwlwifi/pcie/drv.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/net/wireless/intel/iwlwifi/pcie/drv.c b/drivers/net/wireless/intel/iwlwifi/pcie/drv.c
> index c574f041f096..81e8f2fc4982 100644
> --- a/drivers/net/wireless/intel/iwlwifi/pcie/drv.c
> +++ b/drivers/net/wireless/intel/iwlwifi/pcie/drv.c
> @@ -1341,7 +1341,7 @@ iwl_pci_find_dev_info(u16 device, u16 subsystem_device,
>  {
>         int i;
>
> -       for (i = ARRAY_SIZE(iwl_dev_info_table) - 1; i >= 0; i--) {
> +       for (i = (int)ARRAY_SIZE(iwl_dev_info_table) - 1; i >= 0; i--) {

Perhaps `i` could be a `size_t` instead of an `int`?

size_t i = ARRAY_SIZE(iwl_dev_info_table);
while (i--) {
  ...

>                 const struct iwl_dev_info *dev_info = &iwl_dev_info_table[i];
>
>                 if (dev_info->device != (u16)IWL_CFG_ANY &&
> --
> 2.29.2
>


-- 
Thanks,
~Nick Desaulniers

^ permalink raw reply	[flat|nested] 8+ messages in thread

* [PATCH] iwlwifi: pcie: fix constant-conversion warning
@ 2021-11-04 13:37 Arnd Bergmann
  2021-11-10 21:38 ` Nick Desaulniers
  0 siblings, 1 reply; 8+ messages in thread
From: Arnd Bergmann @ 2021-11-04 13:37 UTC (permalink / raw)
  To: Luca Coelho, Kalle Valo, David S. Miller, Jakub Kicinski, Johannes Berg
  Cc: Arnd Bergmann, Nathan Chancellor, Nick Desaulniers, Yaara Baruch,
	Matti Gottlieb, Emmanuel Grumbach, linux-wireless, netdev,
	linux-kernel, llvm

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 (int) cast makes that clearer to the compiler.

Fixes: 3f7320428fa4 ("iwlwifi: pcie: simplify iwl_pci_find_dev_info()")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
 drivers/net/wireless/intel/iwlwifi/pcie/drv.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/wireless/intel/iwlwifi/pcie/drv.c b/drivers/net/wireless/intel/iwlwifi/pcie/drv.c
index c574f041f096..81e8f2fc4982 100644
--- a/drivers/net/wireless/intel/iwlwifi/pcie/drv.c
+++ b/drivers/net/wireless/intel/iwlwifi/pcie/drv.c
@@ -1341,7 +1341,7 @@ iwl_pci_find_dev_info(u16 device, u16 subsystem_device,
 {
 	int i;
 
-	for (i = ARRAY_SIZE(iwl_dev_info_table) - 1; i >= 0; i--) {
+	for (i = (int)ARRAY_SIZE(iwl_dev_info_table) - 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


^ permalink raw reply related	[flat|nested] 8+ messages in thread

end of thread, other threads:[~2021-11-11  7:33 UTC | newest]

Thread overview: 8+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2021-10-29 15:42 [PATCH] iwlwifi: pcie: fix constant-conversion warning Arnd Bergmann
2021-10-31  7:06 ` Kalle Valo
2021-11-01  7:29   ` Coelho, Luciano
2021-11-01  7:32     ` Coelho, Luciano
2021-11-04 13:37 Arnd Bergmann
2021-11-10 21:38 ` Nick Desaulniers
2021-11-10 21:39   ` Nick Desaulniers
2021-11-11  7:33   ` Arnd Bergmann

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