On Mon, Apr 14, 2025 at 6:25 PM Brahmajit <brahmajit.xyz@xxxxxxxxx> wrote:
>
> 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?
No, this problem will be taken care of differently.
Thanks!
