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author | Marvin Häuser <mhaeuser@posteo.de> | 2023-03-22 00:02:40 -0700 |
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committer | mergify[bot] <37929162+mergify[bot]@users.noreply.github.com> | 2023-04-01 23:11:44 +0000 |
commit | 836042ffd8f1b423d76d01dbdb19982ee5339205 (patch) | |
tree | 463e06b6bc15726e6000cafb77bcb597feb5c1b5 /MdePkg/Include/Base.h | |
parent | 24e6daa2bcfb64bbe871f76d8e9774d67f247717 (diff) | |
download | edk2-836042ffd8f1b423d76d01dbdb19982ee5339205.zip edk2-836042ffd8f1b423d76d01dbdb19982ee5339205.tar.gz edk2-836042ffd8f1b423d76d01dbdb19982ee5339205.tar.bz2 |
MdePkg/Base.h: Introduce various alignment-related macros
ALIGNOF: Determining the alignment requirement of data types is
crucial to ensure safe memory accesses when parsing untrusted data.
IS_POW2: Determining whether a value is a power of two is important
to verify whether untrusted values are valid alignment values.
IS_ALIGNED: In combination with ALIGNOF data offsets can be verified.
A more general version of the IS_ALIGNED macro previously defined by
several modules.
ADDRESS_IS_ALIGNED: Variant of IS_ALIGNED for pointers and addresses.
Replaces module-specific definitions throughout the code base.
ALIGN_VALUE_ADDEND: The addend to align up can be used to directly
determine the required offset for data alignment.
Cc: Michael D Kinney <michael.d.kinney@intel.com>
Cc: Liming Gao <gaoliming@byosoft.com.cn>
Cc: Zhiguang Liu <zhiguang.liu@intel.com>
Cc: Vitaly Cheptsov <vit9696@protonmail.com>
Signed-off-by: Marvin Häuser <mhaeuser@posteo.de>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Reviewed-by: Michael D Kinney <michael.d.kinney@intel.com>
Diffstat (limited to 'MdePkg/Include/Base.h')
-rw-r--r-- | MdePkg/Include/Base.h | 98 |
1 files changed, 97 insertions, 1 deletions
diff --git a/MdePkg/Include/Base.h b/MdePkg/Include/Base.h index e89c849..6597e44 100644 --- a/MdePkg/Include/Base.h +++ b/MdePkg/Include/Base.h @@ -759,6 +759,40 @@ typedef UINTN *BASE_LIST; #endif
/**
+ Returns the alignment requirement of a type.
+
+ @param TYPE The name of the type to retrieve the alignment requirement of.
+
+ @return Alignment requirement, in Bytes, of TYPE.
+**/
+#if defined (__cplusplus)
+//
+// Standard C++ operator.
+//
+#define ALIGNOF(TYPE) alignof (TYPE)
+#elif defined (__GNUC__) || defined (__clang__) || (defined (_MSC_VER) && _MSC_VER >= 1900)
+//
+// All supported versions of GCC and Clang, as well as MSVC 2015 and later,
+// support the standard operator _Alignof.
+//
+#define ALIGNOF(TYPE) _Alignof (TYPE)
+#elif defined (_MSC_EXTENSIONS)
+//
+// Earlier versions of MSVC, at least MSVC 2008 and later, support the vendor
+// extension __alignof.
+//
+#define ALIGNOF(TYPE) __alignof (TYPE)
+#else
+//
+// For compilers that do not support inbuilt alignof operators, use OFFSET_OF.
+// CHAR8 is known to have both a size and an alignment requirement of 1 Byte.
+// As such, A must be located exactly at the offset equal to its alignment
+// requirement.
+//
+#define ALIGNOF(TYPE) OFFSET_OF (struct { CHAR8 C; TYPE A; }, A)
+#endif
+
+/**
Portable definition for compile time assertions.
Equivalent to C11 static_assert macro from assert.h.
@@ -793,6 +827,21 @@ STATIC_ASSERT (sizeof (CHAR16) == 2, "sizeof (CHAR16) does not meet UEFI Specif STATIC_ASSERT (sizeof (L'A') == 2, "sizeof (L'A') does not meet UEFI Specification Data Type requirements");
STATIC_ASSERT (sizeof (L"A") == 4, "sizeof (L\"A\") does not meet UEFI Specification Data Type requirements");
+STATIC_ASSERT (ALIGNOF (BOOLEAN) == sizeof (BOOLEAN), "Alignment of BOOLEAN does not meet UEFI Specification Data Type requirements");
+STATIC_ASSERT (ALIGNOF (INT8) == sizeof (INT8), "Alignment of INT8 does not meet UEFI Specification Data Type requirements");
+STATIC_ASSERT (ALIGNOF (UINT8) == sizeof (UINT8), "Alignment of INT16 does not meet UEFI Specification Data Type requirements");
+STATIC_ASSERT (ALIGNOF (INT16) == sizeof (INT16), "Alignment of INT16 does not meet UEFI Specification Data Type requirements");
+STATIC_ASSERT (ALIGNOF (UINT16) == sizeof (UINT16), "Alignment of UINT16 does not meet UEFI Specification Data Type requirements");
+STATIC_ASSERT (ALIGNOF (INT32) == sizeof (INT32), "Alignment of INT32 does not meet UEFI Specification Data Type requirements");
+STATIC_ASSERT (ALIGNOF (UINT32) == sizeof (UINT32), "Alignment of UINT32 does not meet UEFI Specification Data Type requirements");
+STATIC_ASSERT (ALIGNOF (INT64) == sizeof (INT64), "Alignment of INT64 does not meet UEFI Specification Data Type requirements");
+STATIC_ASSERT (ALIGNOF (UINT64) == sizeof (UINT64), "Alignment of UINT64 does not meet UEFI Specification Data Type requirements");
+STATIC_ASSERT (ALIGNOF (CHAR8) == sizeof (CHAR8), "Alignment of CHAR8 does not meet UEFI Specification Data Type requirements");
+STATIC_ASSERT (ALIGNOF (CHAR16) == sizeof (CHAR16), "Alignment of CHAR16 does not meet UEFI Specification Data Type requirements");
+STATIC_ASSERT (ALIGNOF (INTN) == sizeof (INTN), "Alignment of INTN does not meet UEFI Specification Data Type requirements");
+STATIC_ASSERT (ALIGNOF (UINTN) == sizeof (UINTN), "Alignment of UINTN does not meet UEFI Specification Data Type requirements");
+STATIC_ASSERT (ALIGNOF (VOID *) == sizeof (VOID *), "Alignment of VOID * does not meet UEFI Specification Data Type requirements");
+
//
// The following three enum types are used to verify that the compiler
// configuration for enum types is compliant with Section 2.3.1 of the
@@ -816,6 +865,10 @@ STATIC_ASSERT (sizeof (__VERIFY_UINT8_ENUM_SIZE) == 4, "Size of enum does not me STATIC_ASSERT (sizeof (__VERIFY_UINT16_ENUM_SIZE) == 4, "Size of enum does not meet UEFI Specification Data Type requirements");
STATIC_ASSERT (sizeof (__VERIFY_INT32_ENUM_SIZE) == 4, "Size of enum does not meet UEFI Specification Data Type requirements");
+STATIC_ASSERT (ALIGNOF (__VERIFY_UINT8_ENUM_SIZE) == sizeof (__VERIFY_UINT8_ENUM_SIZE), "Alignment of enum does not meet UEFI Specification Data Type requirements");
+STATIC_ASSERT (ALIGNOF (__VERIFY_UINT16_ENUM_SIZE) == sizeof (__VERIFY_UINT16_ENUM_SIZE), "Alignment of enum does not meet UEFI Specification Data Type requirements");
+STATIC_ASSERT (ALIGNOF (__VERIFY_INT32_ENUM_SIZE) == sizeof (__VERIFY_INT32_ENUM_SIZE), "Alignment of enum does not meet UEFI Specification Data Type requirements");
+
/**
Macro that returns a pointer to the data structure that contains a specified field of
that data structure. This is a lightweight method to hide information by placing a
@@ -838,6 +891,49 @@ STATIC_ASSERT (sizeof (__VERIFY_INT32_ENUM_SIZE) == 4, "Size of enum does not me #define BASE_CR(Record, TYPE, Field) ((TYPE *) ((CHAR8 *) (Record) - OFFSET_OF (TYPE, Field)))
/**
+ Checks whether a value is a power of two.
+
+ @param Value The value to check.
+
+ @retval TRUE Value is a power of two.
+ @retval FALSE Value is not a power of two.
+**/
+#define IS_POW2(Value) ((Value) != 0U && ((Value) & ((Value) - 1U)) == 0U)
+
+/**
+ Checks whether a value is aligned by a specified alignment.
+
+ @param Value The value to check.
+ @param Alignment The alignment boundary used to check against.
+
+ @retval TRUE Value is aligned by Alignment.
+ @retval FALSE Value is not aligned by Alignment.
+**/
+#define IS_ALIGNED(Value, Alignment) (((Value) & ((Alignment) - 1U)) == 0U)
+
+/**
+ Checks whether a pointer or address is aligned by a specified alignment.
+
+ @param Address The pointer or address to check.
+ @param Alignment The alignment boundary used to check against.
+
+ @retval TRUE Address is aligned by Alignment.
+ @retval FALSE Address is not aligned by Alignment.
+**/
+#define ADDRESS_IS_ALIGNED(Address, Alignment) IS_ALIGNED ((UINTN) (Address), Alignment)
+
+/**
+ Determines the addend to add to a value to round it up to the next boundary of
+ a specified alignment.
+
+ @param Value The value to round up.
+ @param Alignment The alignment boundary used to return the addend.
+
+ @return Addend to round Value up to alignment boundary Alignment.
+**/
+#define ALIGN_VALUE_ADDEND(Value, Alignment) (((Alignment) - (Value)) & ((Alignment) - 1U))
+
+/**
Rounds a value up to the next boundary using a specified alignment.
This function rounds Value up to the next boundary using the specified Alignment.
@@ -849,7 +945,7 @@ STATIC_ASSERT (sizeof (__VERIFY_INT32_ENUM_SIZE) == 4, "Size of enum does not me @return A value up to the next boundary.
**/
-#define ALIGN_VALUE(Value, Alignment) ((Value) + (((Alignment) - (Value)) & ((Alignment) - 1)))
+#define ALIGN_VALUE(Value, Alignment) ((Value) + ALIGN_VALUE_ADDEND (Value, Alignment))
/**
Adjust a pointer by adding the minimum offset required for it to be aligned on
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