[kvm-unit-tests PATCH v3 03/27] lib: Ensure all struct definition for ACPI tables are packed

Nikos Nikoleris
2022-06-30T10:04:00Z

All ACPI table definitions are provided with precise definitions of
field sizes and offsets, make sure that no compiler optimization can
interfere with the memory layout of the corresponding structs.

Signed-off-by: Nikos Nikoleris <nikos.nikoleris@arm.com>
---
lib/acpi.h | 8 ++++++++
1 file changed, 8 insertions(+)

diff --git a/lib/acpi.h b/lib/acpi.h
index 456e62d..b853a55 100644
--- a/lib/acpi.h
+++ b/lib/acpi.h
@@ -3,6 +3,12 @@

#include "libcflat.h"

+/*
+ * All tables and structures must be byte-packed to match the ACPI
+ * specification, since the tables are provided by the system BIOS
+ */
+#pragma pack(1)
+
#define ACPI_SIGNATURE(c1, c2, c3, c4) \
((c1) | ((c2) << 8) | ((c3) << 16) | ((c4) << 24))

@@ -106,6 +112,8 @@ struct facs_descriptor_rev1
u8 reserved3 [40]; /* Reserved - must be zero */
};

+#pragma pack(0)
+
void set_efi_rsdp(struct rsdp_descriptor *rsdp);
void* find_acpi_table_addr(u32 sig);

--
2.25.1