On Fri, Jan 27, 2023 at 08:43:05PM +0100, Rafael J. Wysocki wrote: > 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. I think a "make clean" is needed first? It builds for me... -- Kees Cook
