Re: [PATCH 1/1] ACPI: Fix building with GCC 15

From: Brahmajit
Date: Mon Apr 14 2025 - 12:25:19 EST

On 14.04.2025 21:46, Brahmajit Das wrote:
> Since the Linux kernel initializes many non-C-string char arrays with
> literals. While it would be possible to convert initializers from:
> { "BOOP", ... }
> to something like:
> { { 'B', 'O', 'O', 'P' }, ... }
> that is annoying.
> Making -Wunterminated-string-initialization stay silent about char
> arrays marked with nonstring would be much better.
>
> Without the __attribute__((nonstring)) we would get the following build
> error:
>
> ...
> drivers/acpi/acpica/acpredef.h:903:11: error: initializer-string for array of ‘char’ truncates NUL terminator but destination lacks ‘nonstring’ attribute (5 chars into 4 available) [-Werror=unterminated-string-initialization]
> 903 | {{"_S3D", METHOD_0ARGS,
> | ^~~~~~
> drivers/acpi/acpica/acpredef.h:906:11: error: initializer-string for array of ‘char’ truncates NUL terminator but destination lacks ‘nonstring’ attribute (5 chars into 4 available) [-Werror=unterminated-string-initialization]
> 906 | {{"_S4D", METHOD_0ARGS,
> | ^~~~~~
>
> and,
>
> ...
> drivers/acpi/acpica/nsrepair2.c:115:10: error: initializer-string for array of ‘char’ truncates NUL terminator but destination lacks ‘nonstring’ attribute (5 chars into 4 available) [-Werror=unterminated-string-initialization]
> 115 | {"_ALR", acpi_ns_repair_ALR},
> | ^~~~~~
> drivers/acpi/acpica/nsrepair2.c:116:10: error: initializer-string for array of ‘char’ truncates NUL terminator but destination lacks ‘nonstring’ attribute (5 chars into 4 available) [-Werror=unterminated-string-initialization]
> 116 | {"_CID", acpi_ns_repair_CID},
> ...
>
> Upstream GCC has added this commit
> 622968990beee7499e951590258363545b4a3b57[0][1] which silences warning
> about truncating NUL char when initializing nonstring arrays.
>
> [0]: https://gcc.gnu.org/cgit/gcc/commit/?id=622968990beee7499e951590258363545b4a3b57
> [1]: https://gcc.gnu.org/cgit/gcc/commit/?id=afb46540d3921e96c4cd7ba8fa2c8b0901759455
>
> Thanks to Jakub Jelinek <jakub@xxxxxxxxxxx> for the gcc patch.
>
> Signed-off-by: Brahmajit Das <listout@xxxxxxxxxxx>
> ---
> drivers/acpi/acpica/aclocal.h | 4 ++--
> drivers/acpi/acpica/nsrepair2.c | 2 +-
> drivers/acpi/tables.c | 28 +++++++++++++++-------------
> include/acpi/actbl.h | 3 ++-
> 4 files changed, 20 insertions(+), 17 deletions(-)
>
> diff --git a/drivers/acpi/acpica/aclocal.h b/drivers/acpi/acpica/aclocal.h
> index 6f4fe47c955b..d2cda1b35e59 100644
> --- a/drivers/acpi/acpica/aclocal.h
> +++ b/drivers/acpi/acpica/aclocal.h
> @@ -293,7 +293,7 @@ acpi_status (*acpi_internal_method) (struct acpi_walk_state * walk_state);
> * expected_return_btypes - Allowed type(s) for the return value
> */
> struct acpi_name_info {
> - char name[ACPI_NAMESEG_SIZE];
> + char name[ACPI_NAMESEG_SIZE] __attribute__((nonstring));
> u16 argument_list;
> u8 expected_btypes;
> };
> @@ -370,7 +370,7 @@ typedef acpi_status (*acpi_object_converter) (struct acpi_namespace_node *
> converted_object);
>
> struct acpi_simple_repair_info {
> - char name[ACPI_NAMESEG_SIZE];
> + char name[ACPI_NAMESEG_SIZE] __attribute__((nonstring));
> u32 unexpected_btypes;
> u32 package_index;
> acpi_object_converter object_converter;
> diff --git a/drivers/acpi/acpica/nsrepair2.c b/drivers/acpi/acpica/nsrepair2.c
> index 1bb7b71f07f1..a28b1fa2b1ea 100644
> --- a/drivers/acpi/acpica/nsrepair2.c
> +++ b/drivers/acpi/acpica/nsrepair2.c
> @@ -25,7 +25,7 @@ acpi_status (*acpi_repair_function) (struct acpi_evaluate_info * info,
> return_object_ptr);
>
> typedef struct acpi_repair_info {
> - char name[ACPI_NAMESEG_SIZE];
> + char name[ACPI_NAMESEG_SIZE] __attribute__((nonstring));
> acpi_repair_function repair_function;
>
> } acpi_repair_info;
> diff --git a/drivers/acpi/tables.c b/drivers/acpi/tables.c
> index 2295abbecd14..27104cbb48b5 100644
> --- a/drivers/acpi/tables.c
> +++ b/drivers/acpi/tables.c
> @@ -396,19 +396,21 @@ static u8 __init acpi_table_checksum(u8 *buffer, u32 length)
> }
>
> /* All but ACPI_SIG_RSDP and ACPI_SIG_FACS: */
> -static const char table_sigs[][ACPI_NAMESEG_SIZE] __initconst = {
> - ACPI_SIG_BERT, ACPI_SIG_BGRT, ACPI_SIG_CPEP, ACPI_SIG_ECDT,
> - ACPI_SIG_EINJ, ACPI_SIG_ERST, ACPI_SIG_HEST, ACPI_SIG_MADT,
> - ACPI_SIG_MSCT, ACPI_SIG_SBST, ACPI_SIG_SLIT, ACPI_SIG_SRAT,
> - ACPI_SIG_ASF, ACPI_SIG_BOOT, ACPI_SIG_DBGP, ACPI_SIG_DMAR,
> - ACPI_SIG_HPET, ACPI_SIG_IBFT, ACPI_SIG_IVRS, ACPI_SIG_MCFG,
> - ACPI_SIG_MCHI, ACPI_SIG_SLIC, ACPI_SIG_SPCR, ACPI_SIG_SPMI,
> - ACPI_SIG_TCPA, ACPI_SIG_UEFI, ACPI_SIG_WAET, ACPI_SIG_WDAT,
> - ACPI_SIG_WDDT, ACPI_SIG_WDRT, ACPI_SIG_DSDT, ACPI_SIG_FADT,
> - ACPI_SIG_PSDT, ACPI_SIG_RSDT, ACPI_SIG_XSDT, ACPI_SIG_SSDT,
> - ACPI_SIG_IORT, ACPI_SIG_NFIT, ACPI_SIG_HMAT, ACPI_SIG_PPTT,
> - ACPI_SIG_NHLT, ACPI_SIG_AEST, ACPI_SIG_CEDT, ACPI_SIG_AGDI,
> - ACPI_SIG_NBFT };
> +static const char table_sigs[][ACPI_NAMESEG_SIZE] __initconst
> + __attribute__((nonstring)) = {
> + ACPI_SIG_BERT, ACPI_SIG_BGRT, ACPI_SIG_CPEP, ACPI_SIG_ECDT,
> + ACPI_SIG_EINJ, ACPI_SIG_ERST, ACPI_SIG_HEST, ACPI_SIG_MADT,
> + ACPI_SIG_MSCT, ACPI_SIG_SBST, ACPI_SIG_SLIT, ACPI_SIG_SRAT,
> + ACPI_SIG_ASF, ACPI_SIG_BOOT, ACPI_SIG_DBGP, ACPI_SIG_DMAR,
> + ACPI_SIG_HPET, ACPI_SIG_IBFT, ACPI_SIG_IVRS, ACPI_SIG_MCFG,
> + ACPI_SIG_MCHI, ACPI_SIG_SLIC, ACPI_SIG_SPCR, ACPI_SIG_SPMI,
> + ACPI_SIG_TCPA, ACPI_SIG_UEFI, ACPI_SIG_WAET, ACPI_SIG_WDAT,
> + ACPI_SIG_WDDT, ACPI_SIG_WDRT, ACPI_SIG_DSDT, ACPI_SIG_FADT,
> + ACPI_SIG_PSDT, ACPI_SIG_RSDT, ACPI_SIG_XSDT, ACPI_SIG_SSDT,
> + ACPI_SIG_IORT, ACPI_SIG_NFIT, ACPI_SIG_HMAT, ACPI_SIG_PPTT,
> + ACPI_SIG_NHLT, ACPI_SIG_AEST, ACPI_SIG_CEDT, ACPI_SIG_AGDI,
> + ACPI_SIG_NBFT
> + };
>
> #define ACPI_HEADER_SIZE sizeof(struct acpi_table_header)
>
> diff --git a/include/acpi/actbl.h b/include/acpi/actbl.h
> index 451f6276da49..88ba1b978053 100644
> --- a/include/acpi/actbl.h
> +++ b/include/acpi/actbl.h
> @@ -66,7 +66,8 @@
> ******************************************************************************/
>
> struct acpi_table_header {
> - char signature[ACPI_NAMESEG_SIZE]; /* ASCII table signature */
> + char signature[ACPI_NAMESEG_SIZE]
> + __attribute__((nonstring)); /* ASCII table signature */
> u32 length; /* Length of table in bytes, including this header */
> u8 revision; /* ACPI Specification minor version number */
> u8 checksum; /* To make sum of entire table == 0 */
> --
> 2.49.0
>

Do I need to send the acpica part to GitHub first?

--
Regards,
listout