[edk2-devel] [PATCH v2 1/2] MdePkg/BaseLib: Fix unaligned API prototypes
Michael D Kinney
michael.d.kinney at intel.com
Mon Aug 9 16:15:08 UTC 2021
Hi Marvin,
Can you provide an example of which C compiler is flagging this as
an error and what error message is generated.
Please enter a BZ with this background information and add link to the
BZ in the commit message.
This is a change to the BaseLib class, so we need to make sure there
are no impacts to any existing code. I looks like a safe change
because changing from a pointer to a fixed size type to VOID *
should be compatible. Please add that analysis to the background
in the BZ as well.
Thanks,
Mike
> -----Original Message-----
> From: Marvin Häuser <mhaeuser at posteo.de>
> Sent: Monday, August 9, 2021 2:51 AM
> To: devel at edk2.groups.io
> Cc: Kinney, Michael D <michael.d.kinney at intel.com>; Liming Gao <gaoliming at byosoft.com.cn>; Liu, Zhiguang
> <zhiguang.liu at intel.com>; Vitaly Cheptsov <vit9696 at protonmail.com>
> Subject: [PATCH v2 1/2] MdePkg/BaseLib: Fix unaligned API prototypes
>
> C prohibits not only dereferencing but also casting to unaligned
> pointers. Thus, the current set of unaligned APIs cannot be called
> safely. Update their prototypes to take VOID * pointers, which must
> be able to represent any valid pointer.
>
> Cc: Michael D Kinney <michael.d.kinney at intel.com>
> Cc: Liming Gao <gaoliming at byosoft.com.cn>
> Cc: Zhiguang Liu <zhiguang.liu at intel.com>
> Cc: Vitaly Cheptsov <vit9696 at protonmail.com>
> Signed-off-by: Marvin Häuser <mhaeuser at posteo.de>
> ---
> MdePkg/Library/BaseLib/Arm/Unaligned.c | 14 ++++-----
> MdePkg/Library/BaseLib/Unaligned.c | 32 ++++++++++----------
> MdePkg/Include/Library/BaseLib.h | 16 +++++-----
> 3 files changed, 31 insertions(+), 31 deletions(-)
>
> diff --git a/MdePkg/Library/BaseLib/Arm/Unaligned.c b/MdePkg/Library/BaseLib/Arm/Unaligned.c
> index e9934e7003cb..57f19fc44e0b 100644
> --- a/MdePkg/Library/BaseLib/Arm/Unaligned.c
> +++ b/MdePkg/Library/BaseLib/Arm/Unaligned.c
> @@ -59,7 +59,7 @@ ReadUnaligned16 (
> UINT16
>
> EFIAPI
>
> WriteUnaligned16 (
>
> - OUT UINT16 *Buffer,
>
> + OUT VOID *Buffer,
>
> IN UINT16 Value
>
> )
>
> {
>
> @@ -87,7 +87,7 @@ WriteUnaligned16 (
> UINT32
>
> EFIAPI
>
> ReadUnaligned24 (
>
> - IN CONST UINT32 *Buffer
>
> + IN CONST VOID *Buffer
>
> )
>
> {
>
> ASSERT (Buffer != NULL);
>
> @@ -116,7 +116,7 @@ ReadUnaligned24 (
> UINT32
>
> EFIAPI
>
> WriteUnaligned24 (
>
> - OUT UINT32 *Buffer,
>
> + OUT VOID *Buffer,
>
> IN UINT32 Value
>
> )
>
> {
>
> @@ -143,7 +143,7 @@ WriteUnaligned24 (
> UINT32
>
> EFIAPI
>
> ReadUnaligned32 (
>
> - IN CONST UINT32 *Buffer
>
> + IN CONST VOID *Buffer
>
> )
>
> {
>
> UINT16 LowerBytes;
>
> @@ -175,7 +175,7 @@ ReadUnaligned32 (
> UINT32
>
> EFIAPI
>
> WriteUnaligned32 (
>
> - OUT UINT32 *Buffer,
>
> + OUT VOID *Buffer,
>
> IN UINT32 Value
>
> )
>
> {
>
> @@ -202,7 +202,7 @@ WriteUnaligned32 (
> UINT64
>
> EFIAPI
>
> ReadUnaligned64 (
>
> - IN CONST UINT64 *Buffer
>
> + IN CONST VOID *Buffer
>
> )
>
> {
>
> UINT32 LowerBytes;
>
> @@ -234,7 +234,7 @@ ReadUnaligned64 (
> UINT64
>
> EFIAPI
>
> WriteUnaligned64 (
>
> - OUT UINT64 *Buffer,
>
> + OUT VOID *Buffer,
>
> IN UINT64 Value
>
> )
>
> {
>
> diff --git a/MdePkg/Library/BaseLib/Unaligned.c b/MdePkg/Library/BaseLib/Unaligned.c
> index a419cb85e53c..3041adcde606 100644
> --- a/MdePkg/Library/BaseLib/Unaligned.c
> +++ b/MdePkg/Library/BaseLib/Unaligned.c
> @@ -26,12 +26,12 @@
> UINT16
>
> EFIAPI
>
> ReadUnaligned16 (
>
> - IN CONST UINT16 *Buffer
>
> + IN CONST VOID *Buffer
>
> )
>
> {
>
> ASSERT (Buffer != NULL);
>
>
>
> - return *Buffer;
>
> + return *(CONST UINT16 *) Buffer;
>
> }
>
>
>
> /**
>
> @@ -52,13 +52,13 @@ ReadUnaligned16 (
> UINT16
>
> EFIAPI
>
> WriteUnaligned16 (
>
> - OUT UINT16 *Buffer,
>
> + OUT VOID *Buffer,
>
> IN UINT16 Value
>
> )
>
> {
>
> ASSERT (Buffer != NULL);
>
>
>
> - return *Buffer = Value;
>
> + return *(UINT16 *) Buffer = Value;
>
> }
>
>
>
> /**
>
> @@ -77,12 +77,12 @@ WriteUnaligned16 (
> UINT32
>
> EFIAPI
>
> ReadUnaligned24 (
>
> - IN CONST UINT32 *Buffer
>
> + IN CONST VOID *Buffer
>
> )
>
> {
>
> ASSERT (Buffer != NULL);
>
>
>
> - return *Buffer & 0xffffff;
>
> + return *(CONST UINT32 *) Buffer & 0xffffff;
>
> }
>
>
>
> /**
>
> @@ -103,13 +103,13 @@ ReadUnaligned24 (
> UINT32
>
> EFIAPI
>
> WriteUnaligned24 (
>
> - OUT UINT32 *Buffer,
>
> + OUT VOID *Buffer,
>
> IN UINT32 Value
>
> )
>
> {
>
> ASSERT (Buffer != NULL);
>
>
>
> - *Buffer = BitFieldWrite32 (*Buffer, 0, 23, Value);
>
> + *(UINT32 *) Buffer = BitFieldWrite32 (*(CONST UINT32 *) Buffer, 0, 23, Value);
>
> return Value;
>
> }
>
>
>
> @@ -129,12 +129,12 @@ WriteUnaligned24 (
> UINT32
>
> EFIAPI
>
> ReadUnaligned32 (
>
> - IN CONST UINT32 *Buffer
>
> + IN CONST VOID *Buffer
>
> )
>
> {
>
> ASSERT (Buffer != NULL);
>
>
>
> - return *Buffer;
>
> + return *(CONST UINT32 *) Buffer;
>
> }
>
>
>
> /**
>
> @@ -155,13 +155,13 @@ ReadUnaligned32 (
> UINT32
>
> EFIAPI
>
> WriteUnaligned32 (
>
> - OUT UINT32 *Buffer,
>
> + OUT VOID *Buffer,
>
> IN UINT32 Value
>
> )
>
> {
>
> ASSERT (Buffer != NULL);
>
>
>
> - return *Buffer = Value;
>
> + return *(UINT32 *) Buffer = Value;
>
> }
>
>
>
> /**
>
> @@ -180,12 +180,12 @@ WriteUnaligned32 (
> UINT64
>
> EFIAPI
>
> ReadUnaligned64 (
>
> - IN CONST UINT64 *Buffer
>
> + IN CONST VOID *Buffer
>
> )
>
> {
>
> ASSERT (Buffer != NULL);
>
>
>
> - return *Buffer;
>
> + return *(CONST UINT64 *) Buffer;
>
> }
>
>
>
> /**
>
> @@ -206,11 +206,11 @@ ReadUnaligned64 (
> UINT64
>
> EFIAPI
>
> WriteUnaligned64 (
>
> - OUT UINT64 *Buffer,
>
> + OUT VOID *Buffer,
>
> IN UINT64 Value
>
> )
>
> {
>
> ASSERT (Buffer != NULL);
>
>
>
> - return *Buffer = Value;
>
> + return *(UINT64 *) Buffer = Value;
>
> }
>
> diff --git a/MdePkg/Include/Library/BaseLib.h b/MdePkg/Include/Library/BaseLib.h
> index 2452c1d92e51..4d30f0539c6b 100644
> --- a/MdePkg/Include/Library/BaseLib.h
> +++ b/MdePkg/Include/Library/BaseLib.h
> @@ -3420,7 +3420,7 @@ DivS64x64Remainder (
> UINT16
>
> EFIAPI
>
> ReadUnaligned16 (
>
> - IN CONST UINT16 *Buffer
>
> + IN CONST VOID *Buffer
>
> );
>
>
>
>
>
> @@ -3442,7 +3442,7 @@ ReadUnaligned16 (
> UINT16
>
> EFIAPI
>
> WriteUnaligned16 (
>
> - OUT UINT16 *Buffer,
>
> + OUT VOID *Buffer,
>
> IN UINT16 Value
>
> );
>
>
>
> @@ -3463,7 +3463,7 @@ WriteUnaligned16 (
> UINT32
>
> EFIAPI
>
> ReadUnaligned24 (
>
> - IN CONST UINT32 *Buffer
>
> + IN CONST VOID *Buffer
>
> );
>
>
>
>
>
> @@ -3485,7 +3485,7 @@ ReadUnaligned24 (
> UINT32
>
> EFIAPI
>
> WriteUnaligned24 (
>
> - OUT UINT32 *Buffer,
>
> + OUT VOID *Buffer,
>
> IN UINT32 Value
>
> );
>
>
>
> @@ -3506,7 +3506,7 @@ WriteUnaligned24 (
> UINT32
>
> EFIAPI
>
> ReadUnaligned32 (
>
> - IN CONST UINT32 *Buffer
>
> + IN CONST VOID *Buffer
>
> );
>
>
>
>
>
> @@ -3528,7 +3528,7 @@ ReadUnaligned32 (
> UINT32
>
> EFIAPI
>
> WriteUnaligned32 (
>
> - OUT UINT32 *Buffer,
>
> + OUT VOID *Buffer,
>
> IN UINT32 Value
>
> );
>
>
>
> @@ -3549,7 +3549,7 @@ WriteUnaligned32 (
> UINT64
>
> EFIAPI
>
> ReadUnaligned64 (
>
> - IN CONST UINT64 *Buffer
>
> + IN CONST VOID *Buffer
>
> );
>
>
>
>
>
> @@ -3571,7 +3571,7 @@ ReadUnaligned64 (
> UINT64
>
> EFIAPI
>
> WriteUnaligned64 (
>
> - OUT UINT64 *Buffer,
>
> + OUT VOID *Buffer,
>
> IN UINT64 Value
>
> );
>
>
>
> --
> 2.31.1
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