On Wed, Apr 16, 2025 at 1:20 AM Kees Cook <k...@kernel.org> wrote: > > When a character array without a terminating NUL character has a static > initializer, GCC 15's -Wunterminated-string-initialization will only > warn if the array lacks the "nonstring" attribute[1]. Mark the 4-byte > ACPI identifier arrays with __nonstring (and the new __nonstring_array) > to correctly identify the char arrays as "not C strings" and thereby > eliminate the many warnings like this: > > In file included from include/acpi/actbl.h:371, > from include/acpi/acpi.h:26, > from include/linux/acpi.h:26, > from drivers/acpi/tables.c:19: > include/acpi/actbl1.h:30:33: warning: initializer-string for array of 'char' > truncates NUL terminator but destination lacks 'nonstring' attribute (5 chars > into 4 available) [-Wunterminated-string-initialization] > 30 | #define ACPI_SIG_BERT "BERT" /* Boot Error Record Table */ > | ^~~~~~ > drivers/acpi/tables.c:400:9: note: in expansion of macro 'ACPI_SIG_BERT' > 400 | ACPI_SIG_BERT, ACPI_SIG_BGRT, ACPI_SIG_CPEP, ACPI_SIG_ECDT, > | ^~~~~~~~~~~~~ > > Link: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=117178 [1] > Signed-off-by: Kees Cook <k...@kernel.org> > --- > Cc: "Rafael J. Wysocki" <raf...@kernel.org> > Cc: Len Brown <l...@kernel.org> > Cc: Robert Moore <robert.mo...@intel.com> > Cc: linux-a...@vger.kernel.org > Cc: acpica-de...@lists.linux.dev > --- > drivers/acpi/tables.c | 2 +- > include/acpi/actbl.h | 2 +- > 2 files changed, 2 insertions(+), 2 deletions(-) > > diff --git a/drivers/acpi/tables.c b/drivers/acpi/tables.c > index 2295abbecd14..0a9ade7117bd 100644 > --- a/drivers/acpi/tables.c > +++ b/drivers/acpi/tables.c > @@ -396,7 +396,7 @@ 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 = { > +static const char table_sigs[][ACPI_NAMESEG_SIZE] __nonstring_array > __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, > diff --git a/include/acpi/actbl.h b/include/acpi/actbl.h > index 451f6276da49..2fc89704be17 100644 > --- a/include/acpi/actbl.h > +++ b/include/acpi/actbl.h > @@ -66,7 +66,7 @@ > > ******************************************************************************/ > > struct acpi_table_header { > - char signature[ACPI_NAMESEG_SIZE]; /* ASCII table signature */ > + char signature[ACPI_NAMESEG_SIZE] __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 */ > --
Applied as 6.16 material. I've rebased it on top of https://web.git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=9d7a0577c9db35c4cc52db90bc415ea248446472 so basically the hunk in actbl.h is gone. Please see https://web.git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm.git/commit/?h=bleeding-edge&id=18eb45b67544b995a8a6f48a72b816fd75776f52 Thanks!
