On Fri, Jan 27, 2023 at 8:16 PM Kees Cook <keescook@xxxxxxxxxxxx> wrote: > > One-element arrays (and multi-element arrays being treated as > dynamically sized) are deprecated[1] and are being replaced with > flexible array members in support of the ongoing efforts to tighten the > FORTIFY_SOURCE routines on memcpy(), correctly instrument array indexing > with UBSAN_BOUNDS, and to globally enable -fstrict-flex-arrays=3. > > Replace one-element array with flexible-array member in struct > acpi_resource_extended_irq. Replace 4-byte fixed-size array with 4-byte > padding in a union with a flexible-array member in struct > acpi_pci_routing_table. > > This results in no differences in binary output. > > Link: https://github.com/acpica/acpica/pull/813 > Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx> > Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx> > --- > v2: include stddef.h and switch to __DECLARE_FLEX_ARRAY() > v1: https://lore.kernel.org/lkml/20221118181538.never.225-kees@xxxxxxxxxx/ > --- > include/acpi/acrestyp.h | 9 +++++++-- > 1 file changed, 7 insertions(+), 2 deletions(-) > > diff --git a/include/acpi/acrestyp.h b/include/acpi/acrestyp.h > index a7fb8ddb3dc6..250046a7c870 100644 > --- a/include/acpi/acrestyp.h > +++ b/include/acpi/acrestyp.h > @@ -10,6 +10,8 @@ > #ifndef __ACRESTYP_H__ > #define __ACRESTYP_H__ > > +#include <linux/stddef.h> > + > /* > * Definitions for Resource Attributes > */ > @@ -332,7 +334,7 @@ struct acpi_resource_extended_irq { > u8 wake_capable; > u8 interrupt_count; > struct acpi_resource_source resource_source; > - u32 interrupts[1]; > + u32 interrupts[]; > }; > > struct acpi_resource_generic_register { > @@ -679,7 +681,10 @@ struct acpi_pci_routing_table { > u32 pin; > u64 address; /* here for 64-bit alignment */ > u32 source_index; > - char source[4]; /* pad to 64 bits so sizeof() works in all cases */ > + union { > + char pad[4]; /* pad to 64 bits so sizeof() works in all cases */ > + __DECLARE_FLEX_ARRAY(char, source); > + }; > }; > > #endif /* __ACRESTYP_H__ */ > -- With this applied I get: rafael@gratch:~/work/linux-pm/tools/power/acpi> make DESCEND tools/acpidbg MKDIR include CP include CC tools/acpidbg/acpidbg.o In file included from /scratch/rafael/work/linux-pm/tools/power/acpi/include/acpi/acpi.h:27:0, from acpidbg.c:9: /scratch/rafael/work/linux-pm/tools/power/acpi/include/acpi/acrestyp.h:686:3: error: expected specif ier-qualifier-list before ‘__DECLARE_FLEX_ARRAY’ __DECLARE_FLEX_ARRAY(char, source); ^~~~~~~~~~~~~~~~~~~~ make[1]: *** [../../Makefile.rules:25: /scratch/rafael/work/linux-pm/tools/power/acpi/tools/acpidbg/ acpidbg.o] Error 1 make: *** [Makefile:18: acpidbg] Error 2 The tools build successfully without it.
