-----Original Message----- From: Nick Desaulniers ndesaulniers@google.com Sent: Thursday, June 11, 2020 10:06 AM To: Kaneda, Erik erik.kaneda@intel.com Cc: Jung-uk Kim jkim@freebsd.org; Wysocki, Rafael J rafael.j.wysocki@intel.com; Ard Biesheuvel ardb@kernel.org; dvyukov@google.com; glider@google.com; linux-arm- kernel@lists.infradead.org; linux-kernel@vger.kernel.org; lorenzo.pieralisi@arm.com; mark.rutland@arm.com; pcc@google.com; rjw@rjwysocki.net; will@kernel.org; stable@vger.kernel.org; linux- 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 erik.kaneda@intel.com wrote:
From: Jung-uk Kim jkim@FreeBSD.org
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 *)
#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
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