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Message-ID: <a3ea149b-adad-4680-bb59-ae460e8eda04@canonical.com>
Date:   Wed, 6 Dec 2023 17:37:27 +0100
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Subject: Re: [PATCH 1/1] ACPI: XSDT: struct acpi_table_xsdt must be packed
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To:     "Rafael J. Wysocki" <rafael@kernel.org>
Cc:     Robert Moore <robert.moore@intel.com>, Len Brown <lenb@kernel.org>,
        linux-acpi@vger.kernel.org, acpica-devel@lists.linux.dev,
        linux-kernel@vger.kernel.org
References: <20231111134827.174908-1-heinrich.schuchardt@canonical.com>
 <CAJZ5v0gGKuBNBvDj2fNMyCvKTrt2SWfusxyaf7W4jvvfL0nxUg@mail.gmail.com>
From:   Heinrich Schuchardt <heinrich.schuchardt@canonical.com>
In-Reply-To: <CAJZ5v0gGKuBNBvDj2fNMyCvKTrt2SWfusxyaf7W4jvvfL0nxUg@mail.gmail.com>
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On 06.12.23 17:30, Rafael J. Wysocki wrote:
> On Sat, Nov 11, 2023 at 2:48 PM Heinrich Schuchardt
> <heinrich.schuchardt@canonical.com> wrote:
>>
>> According to the ACPI 6.5 specification the component Entry starts at
>> offset 36 in the XSDT table which is not a multiple of 8. Hence we must
>> mark the structure as packed.
> 
> There is #pragma pack(1) at the beginning of actbl.h.  Is it not sufficient?

Sorry I missed that pragma.

> 
>> We did not see an error due to the incorrect packing yet as in
>> acpi_tb_parse_root_table() we use ACPI_ADD_PTR() to find the address of
>> Entry.
>>
>> Signed-off-by: Heinrich Schuchardt <heinrich.schuchardt@canonical.com>
>> ---
>>   include/acpi/actbl.h | 2 +-
>>   1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/include/acpi/actbl.h b/include/acpi/actbl.h
>> index 451f6276da49..1a37ac378765 100644
>> --- a/include/acpi/actbl.h
>> +++ b/include/acpi/actbl.h
>> @@ -148,7 +148,7 @@ struct acpi_table_rsdt {
>>   struct acpi_table_xsdt {
>>          struct acpi_table_header header;        /* Common ACPI table header */
>>          u64 table_offset_entry[1];      /* Array of pointers to ACPI tables */
>> -};
>> +} __packed;
>>
>>   #define ACPI_RSDT_ENTRY_SIZE        (sizeof (u32))
>>   #define ACPI_XSDT_ENTRY_SIZE        (sizeof (u64))
>> --
>> 2.40.1
>>