-----Original Message-----
From: Nick Desaulniers <ndesaulniers@google.com>
Sent: Thursday, June 11, 2020 10:06 AM
To: Kaneda, Erik <redacted>
Cc: Jung-uk Kim <redacted>; Wysocki, Rafael J
[off-list ref]; Ard Biesheuvel [off-list ref];
dvyukov@google.com; glider@google.com; linux-arm-
kernel@lists.infradead.org; linux-kernel@vger.kernel.org;
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acpi@vger.kernel.org; devel@acpica.org
Subject: Re: [Devel] Re: [PATCH] ACPICA: fix UBSAN warning using
__builtin_offsetof
On Thu, Jun 11, 2020 at 9:45 AM Kaneda, Erik [off-list ref]
wrote:
quoted
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)
quoted
#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)
quoted
+#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
quoted
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
Hi,
Sorry about the delayed response.
Looks good at first glance. Wouldn't actypes.h need to include
platform/acenv.h first though? Otherwise you put some header
inclusion order dependency on folks who include actypes.h to first
include acenv.h otherwise we're not getting the definition in terms of
__builtin_offsetof.
Actypes.h is intended for ACPICA use. For files using ACPI_OFFSET, they include headers like acpi.h that ends up including aclinux.h before including actypes.h. For those using ACPI_OFFSET, precedence will be given to the definition in aclinux.h before falling back to the definition in actypes.
Erik
--
Thanks,
~Nick Desaulniers
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