diff mbox series

[kvm-unit-tests,v6,07/32] lib/acpi: Ensure all struct definition for ACPI tables are packed

Message ID 20230530160924.82158-8-nikos.nikoleris@arm.com (mailing list archive)
State New, archived
Headers show
Series EFI and ACPI support for arm64 | expand

Commit Message

Nikos Nikoleris May 30, 2023, 4:08 p.m. UTC 
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>
Reviewed-by: Andrew Jones <andrew.jones@linux.dev>
---
 lib/acpi.h | 9 +++++++++
 1 file changed, 9 insertions(+)
diff mbox series

Patch

diff --git a/lib/acpi.h b/lib/acpi.h
index f9a344e9..7eb18cf3 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 firmware.
+ */
+#pragma pack(1)
+
 #define ACPI_SIGNATURE(c1, c2, c3, c4) \
 	((c1) | ((c2) << 8) | ((c3) << 16) | ((c4) << 24))
 
@@ -103,6 +109,9 @@  struct acpi_table_facs_rev1 {
 	u8 reserved3[40];	/* Reserved - must be zero */
 };
 
+/* Reset to default packing */
+#pragma pack()
+
 void set_efi_rsdp(struct acpi_table_rsdp *rsdp);
 void *find_acpi_table_addr(u32 sig);