[PATCH 22/32] ACPICA: actbl2: Replace 1-element arrays with flexible arrays

Rafael J. Wysocki
2023-04-05T14:01:45Z

From: Kees Cook <kees@outflux.net>

ACPICA commit 44f1af0664599e87bebc3a1260692baa27b2f264

Similar to "Replace one-element array with flexible-array", replace the
1-element array with a proper flexible array member as defined by C99.

This allows the code to operate without tripping compile-time and run-
time bounds checkers (e.g. via __builtin_object_size(), -fsanitize=bounds,
and/or -fstrict-flex-arrays=3).

The sizeof() uses with struct acpi_nfit_flush_address and struct
acpi_nfit_smbios have been adjusted to drop the open-coded subtraction
of the trailing single element. The result is no binary differences in
.text nor .data sections.

Link: https://github.com/acpica/acpica/commit/44f1af06
Signed-off-by: Bob Moore <robert.moore@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
---
drivers/acpi/nfit/core.c | 2 +-
include/acpi/actbl2.h | 16 ++++++++--------
2 files changed, 9 insertions(+), 9 deletions(-)

diff --git a/drivers/acpi/nfit/core.c b/drivers/acpi/nfit/core.c
index 4e48d6db05eb..981f8b0f595d 100644
--- a/drivers/acpi/nfit/core.c
+++ b/drivers/acpi/nfit/core.c
@@ -3477,7 +3477,7 @@ static __init int nfit_init(void)
BUILD_BUG_ON(sizeof(struct acpi_nfit_system_address) != 64);
BUILD_BUG_ON(sizeof(struct acpi_nfit_memory_map) != 48);
BUILD_BUG_ON(sizeof(struct acpi_nfit_interleave) != 20);
- BUILD_BUG_ON(sizeof(struct acpi_nfit_smbios) != 9);
+ BUILD_BUG_ON(sizeof(struct acpi_nfit_smbios) != 8);
BUILD_BUG_ON(sizeof(struct acpi_nfit_control_region) != 80);
BUILD_BUG_ON(sizeof(struct acpi_nfit_data_region) != 40);
BUILD_BUG_ON(sizeof(struct acpi_nfit_capabilities) != 16);
diff --git a/include/acpi/actbl2.h b/include/acpi/actbl2.h
index db292f325696..6d3251ea4c53 100644
--- a/include/acpi/actbl2.h
+++ b/include/acpi/actbl2.h
@@ -397,7 +397,7 @@ struct acpi_iort_node {
u32 identifier;
u32 mapping_count;
u32 mapping_offset;
- char node_data[1];
+ char node_data[];
};

/* Values for subtable Type above */
@@ -453,14 +453,14 @@ struct acpi_iort_memory_access {
*/
struct acpi_iort_its_group {
u32 its_count;
- u32 identifiers[1]; /* GIC ITS identifier array */
+ u32 identifiers[]; /* GIC ITS identifier array */
};

struct acpi_iort_named_component {
u32 node_flags;
u64 memory_properties; /* Memory access properties */
u8 memory_address_limit; /* Memory address size limit */
- char device_name[1]; /* Path of namespace object */
+ char device_name[]; /* Path of namespace object */
};

/* Masks for Flags field above */
@@ -474,7 +474,7 @@ struct acpi_iort_root_complex {
u32 pci_segment_number;
u8 memory_address_limit; /* Memory address size limit */
u16 pasid_capabilities; /* PASID Capabilities */
- u8 reserved[1]; /* Reserved, must be zero */
+ u8 reserved[]; /* Reserved, must be zero */
};

/* Masks for ats_attribute field above */
@@ -496,7 +496,7 @@ struct acpi_iort_smmu {
u32 context_interrupt_offset;
u32 pmu_interrupt_count;
u32 pmu_interrupt_offset;
- u64 interrupts[1]; /* Interrupt array */
+ u64 interrupts[]; /* Interrupt array */
};

/* Values for Model field above */
@@ -975,7 +975,7 @@ struct acpi_madt_local_sapic {
u8 reserved[3]; /* Reserved, must be zero */
u32 lapic_flags;
u32 uid; /* Numeric UID - ACPI 3.0 */
- char uid_string[1]; /* String UID - ACPI 3.0 */
+ char uid_string[]; /* String UID - ACPI 3.0 */
};

/* 8: Platform Interrupt Source */
@@ -1708,7 +1708,7 @@ struct acpi_nfit_interleave {
struct acpi_nfit_smbios {
struct acpi_nfit_header header;
u32 reserved; /* Reserved, must be zero */
- u8 data[1]; /* Variable length */
+ u8 data[]; /* Variable length */
};

/* 4: NVDIMM Control Region Structure */
@@ -1765,7 +1765,7 @@ struct acpi_nfit_flush_address {
u32 device_handle;
u16 hint_count;
u8 reserved[6]; /* Reserved, must be zero */
- u64 hint_address[1]; /* Variable length */
+ u64 hint_address[]; /* Variable length */
};

/* 7: Platform Capabilities Structure */
--
2.35.3