diff mbox series

ACPICA: Fix sprintf() INT_MAX -Wformat-truncation= warn

Message ID 20221116152258.28772-1-skhan@linuxfoundation.org
State New
Headers
Series ACPICA: Fix sprintf() INT_MAX -Wformat-truncation= warn |

Commit Message

Shuah Khan Nov. 16, 2022, 3:22 p.m. UTC 
  utprint module is included in tools/acpidump and when acpidump is built,
the following warning occurs.

 CC       tools/acpidump/utprint.o
/usr/include/x86_64-linux-gnu/bits/stdio2.h: In function ‘sprintf’:
../../../../../drivers/acpi/acpica/utprint.c:602:18: warning: specified bound 4294901760 exceeds ‘INT_MAX’ [-Wformat-truncation=]
  602 |         length = vsnprintf(string, ACPI_UINT32_MAX-ACPI_UINT16_MAX,
      |                  ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  603 |                         format, args);
      |                         ~~~~~~~~~~~~~

Fix sprintf() to use ACPI_UINT32_MAX/2 to get rid of the truncate problem.
This change is inline other sprintf() implementations.

If using ACPI_UINT32_MAX is necessary in the kernel, acpidump might require
special case to get rid of this truncate problem.

Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
---
 drivers/acpi/acpica/utprint.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

Comments

Rafael J. Wysocki Nov. 16, 2022, 7:05 p.m. UTC | #1 
On Wed, Nov 16, 2022 at 4:23 PM Shuah Khan <skhan@linuxfoundation.org> wrote:
>
> utprint module is included in tools/acpidump and when acpidump is built,
> the following warning occurs.
>
>  CC       tools/acpidump/utprint.o
> /usr/include/x86_64-linux-gnu/bits/stdio2.h: In function ‘sprintf’:
> ../../../../../drivers/acpi/acpica/utprint.c:602:18: warning: specified bound 4294901760 exceeds ‘INT_MAX’ [-Wformat-truncation=]
>   602 |         length = vsnprintf(string, ACPI_UINT32_MAX-ACPI_UINT16_MAX,
>       |                  ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>   603 |                         format, args);
>       |                         ~~~~~~~~~~~~~
>
> Fix sprintf() to use ACPI_UINT32_MAX/2 to get rid of the truncate problem.
> This change is inline other sprintf() implementations.
>
> If using ACPI_UINT32_MAX is necessary in the kernel, acpidump might require
> special case to get rid of this truncate problem.

As ACPICA material, this should be submitted to the upstream project
on GitHub and honestly I'm not sure if it is going to be resolved this
way there.

> Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
> ---
>  drivers/acpi/acpica/utprint.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/acpi/acpica/utprint.c b/drivers/acpi/acpica/utprint.c
> index d5aa2109847f..02cff16c8f77 100644
> --- a/drivers/acpi/acpica/utprint.c
> +++ b/drivers/acpi/acpica/utprint.c
> @@ -599,7 +599,7 @@ int sprintf(char *string, const char *format, ...)
>         int length;
>
>         va_start(args, format);
> -       length = vsnprintf(string, ACPI_UINT32_MAX, format, args);
> +       length = vsnprintf(string, ACPI_UINT32_MAX/2, format, args);
>         va_end(args);
>
>         return (length);
> --
> 2.34.1
>
Shuah Khan Nov. 16, 2022, 7:53 p.m. UTC | #2 
On 11/16/22 12:05, Rafael J. Wysocki wrote:
> On Wed, Nov 16, 2022 at 4:23 PM Shuah Khan <skhan@linuxfoundation.org> wrote:
>>
>> utprint module is included in tools/acpidump and when acpidump is built,
>> the following warning occurs.
>>
>>   CC       tools/acpidump/utprint.o
>> /usr/include/x86_64-linux-gnu/bits/stdio2.h: In function ‘sprintf’:
>> ../../../../../drivers/acpi/acpica/utprint.c:602:18: warning: specified bound 4294901760 exceeds ‘INT_MAX’ [-Wformat-truncation=]
>>    602 |         length = vsnprintf(string, ACPI_UINT32_MAX-ACPI_UINT16_MAX,
>>        |                  ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>>    603 |                         format, args);
>>        |                         ~~~~~~~~~~~~~
>>
>> Fix sprintf() to use ACPI_UINT32_MAX/2 to get rid of the truncate problem.
>> This change is inline other sprintf() implementations.
>>
>> If using ACPI_UINT32_MAX is necessary in the kernel, acpidump might require
>> special case to get rid of this truncate problem.
> 
> As ACPICA material, this should be submitted to the upstream project
> on GitHub and honestly I'm not sure if it is going to be resolved this
> way there.

Thank you for your review. I will send this ACPICA upstream project.

thanks,
-- Shuah
diff mbox series

Patch

diff --git a/drivers/acpi/acpica/utprint.c b/drivers/acpi/acpica/utprint.c
index d5aa2109847f..02cff16c8f77 100644
--- a/drivers/acpi/acpica/utprint.c
+++ b/drivers/acpi/acpica/utprint.c
@@ -599,7 +599,7 @@  int sprintf(char *string, const char *format, ...)
 	int length;
 
 	va_start(args, format);
-	length = vsnprintf(string, ACPI_UINT32_MAX, format, args);
+	length = vsnprintf(string, ACPI_UINT32_MAX/2, format, args);
 	va_end(args);
 
 	return (length);