Re: [PATCH] acpi: respect const qualifier

From: Sam Protsenko
Date: Fri Apr 25 2014 - 11:02:30 EST


> This is not a mainline kernel problem, surely?

Correct, this warning is just example of possible issue that can be
occurred because of missing "const" qualifier. Actually I saw this
warning in Linaro ACPI kernel (intended for ARMv8 AArch64
architecture).

But I believe that this issue should be fixed in mainline kernel,
because it can cause the same warning in the future.

On 21 April 2014 23:44, Rafael J. Wysocki <rjw@xxxxxxxxxxxxx> wrote:
> On Thursday, April 17, 2014 06:53:26 PM Semen Protsenko wrote:
>> This patch fixes next warning:
>>
>> <------------------------------- cut here --------------------------------->
>> drivers/acpi/property.c: In function âacpi_free_propertiesâ:
>> drivers/acpi/property.c:35:2: warning: passing argument 1 of âacpi_os_freeâ
>> discards âconstâ qualifier from pointer
>> target type [enabled by default]
>>
>> ACPI_FREE(adev->properties);
>> <------------------------------- cut here --------------------------------->
>
> This is not a mainline kernel problem, surely?
>
>>
>> The problem is next:
>>
>> - acpi_free_properties() calls ACPI_FREE(), passing "const *"
>> parameter to it
>> - ACPI_FREE() is macro for acpi_os_free()
>> - acpi_os_free() takes "void *" parameter
>> - acpi_os_free() calls kfree()
>> - but kfree() requires "const void *" parameter
>>
>> So acpi_os_free() should require "const void *" parameter as well.
>>
>> Signed-off-by: Semen Protsenko <semen.protsenko@xxxxxxxxxx>
>> ---
>> include/acpi/platform/aclinux.h | 2 +-
>> 1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/include/acpi/platform/aclinux.h b/include/acpi/platform/aclinux.h
>> index 93c55ed..c6fa763 100644
>> --- a/include/acpi/platform/aclinux.h
>> +++ b/include/acpi/platform/aclinux.h
>> @@ -174,7 +174,7 @@ static inline void *acpi_os_allocate_zeroed(acpi_size size)
>> #define ACPI_USE_ALTERNATE_PROTOTYPE_acpi_os_allocate_zeroed
>> #define USE_NATIVE_ALLOCATE_ZEROED
>>
>> -static inline void acpi_os_free(void *memory)
>> +static inline void acpi_os_free(const void *memory)
>> {
>> kfree(memory);
>> }
>>
>
> --
> I speak only for myself.
> Rafael J. Wysocki, Intel Open Source Technology Center.
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