Re: [Devel] Re: [PATCH] ACPICA: fix UBSAN warning using __builtin_offsetof

quoted

From: Jung-uk Kim <redacted>

Actually, I think we should let platform-specific acfoo.h decide what to
do here, i.e.,

That's a better solution. For Linux, it would look something like this:

--- a/include/acpi/actypes.h
+++ b/include/acpi/actypes.h

@@ -508,10 +508,15 @@ typedef u64 acpi_integer;

 #define ACPI_TO_POINTER(i)              ACPI_CAST_PTR (void, (acpi_size) (i))
 #define ACPI_TO_INTEGER(p)              ACPI_PTR_DIFF (p, (void *) 0)
-#define ACPI_OFFSET(d, f)               ACPI_PTR_DIFF (&(((d *) 0)->f), (void *) 0)
 #define ACPI_PHYSADDR_TO_PTR(i)         ACPI_TO_POINTER(i)
 #define ACPI_PTR_TO_PHYSADDR(i)         ACPI_TO_INTEGER(i)

+/* Platforms may want to define their own ACPI_OFFSET */
+
+#ifndef ACPI_OFFSET
+#define ACPI_OFFSET(d, f)               ACPI_PTR_DIFF (&(((d *) 0)->f), (void *) 0)
+#endif
+
 /* Optimizations for 4-character (32-bit) acpi_name manipulation */

 #ifndef ACPI_MISALIGNMENT_NOT_SUPPORTED

diff --git a/include/acpi/platform/aclinux.h b/include/acpi/platform/aclinux.h
index 987e2af7c335..5d1ca6015fce 100644
--- a/include/acpi/platform/aclinux.h
+++ b/include/acpi/platform/aclinux.h

@@ -71,6 +71,11 @@
 #undef ACPI_DEBUG_DEFAULT
 #define ACPI_DEBUG_DEFAULT          (ACPI_LV_INFO | ACPI_LV_REPAIR)

+/* Use gcc's builtin offset instead of the default */
+
+#undef ACPI_OFFSET
+#define ACPI_OFFSET(a,b)            __builtin_offsetof(a,b)
+
 #ifndef CONFIG_ACPI