From:   "Rafael J. Wysocki" <rjw@rjwysocki.net>
To:     Linux ACPI <linux-acpi@vger.kernel.org>
Cc:     LKML <linux-kernel@vger.kernel.org>,
        Bob Moore <robert.moore@intel.com>
Subject: [PATCH 01/19] ACPICA: actypes.h: Expand the ACPI_ACCESS_ definitions
Date:   Wed, 22 Dec 2021 16:57:34 +0100
Message-ID: <5779634.lOV4Wx5bFT@kreacher>
In-Reply-To: <11889746.O9o76ZdvQC@kreacher>
References: <11889746.O9o76ZdvQC@kreacher>
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From: Mark Langsdorf <mlangsdo@redhat.com>

ACPICA commit bc02c76d518135531483dfc276ed28b7ee632ce1

The current ACPI_ACCESS_*_WIDTH defines do not provide a way to
test that size is small enough to not cause an overflow when
applied to a 32-bit integer.

Rather than adding more magic numbers, add ACPI_ACCESS_*_SHIFT,
ACPI_ACCESS_*_MAX, and ACPI_ACCESS_*_DEFAULT #defines and
redefine ACPI_ACCESS_*_WIDTH in terms of the new #defines.

This was inititally reported on Linux where a size of 102 in
ACPI_ACCESS_BIT_WIDTH caused an overflow error in the SPCR
initialization code.

Link: https://github.com/acpica/acpica/commit/bc02c76d
Signed-off-by: Mark Langsdorf <mlangsdo@redhat.com>
Signed-off-by: Bob Moore <robert.moore@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
---
 include/acpi/actypes.h | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/include/acpi/actypes.h b/include/acpi/actypes.h
index ff8b3c913f21..248242dca28d 100644
--- a/include/acpi/actypes.h
+++ b/include/acpi/actypes.h
@@ -536,8 +536,14 @@ typedef u64 acpi_integer;
  * Can be used with access_width of struct acpi_generic_address and access_size of
  * struct acpi_resource_generic_register.
  */
-#define ACPI_ACCESS_BIT_WIDTH(size)     (1 << ((size) + 2))
-#define ACPI_ACCESS_BYTE_WIDTH(size)    (1 << ((size) - 1))
+#define ACPI_ACCESS_BIT_SHIFT		2
+#define ACPI_ACCESS_BYTE_SHIFT		-1
+#define ACPI_ACCESS_BIT_MAX		(31 - ACPI_ACCESS_BIT_SHIFT)
+#define ACPI_ACCESS_BYTE_MAX		(31 - ACPI_ACCESS_BYTE_SHIFT)
+#define ACPI_ACCESS_BIT_DEFAULT		(8 - ACPI_ACCESS_BIT_SHIFT)
+#define ACPI_ACCESS_BYTE_DEFAULT	(8 - ACPI_ACCESS_BYTE_SHIFT)
+#define ACPI_ACCESS_BIT_WIDTH(size)	(1 << ((size) + ACPI_ACCESS_BIT_SHIFT))
+#define ACPI_ACCESS_BYTE_WIDTH(size)	(1 << ((size) + ACPI_ACCESS_BYTE_SHIFT))
 
 /*******************************************************************************
  *
-- 
2.26.2