[PATCH EDK2 v1 0/1] ArmPkg/ArmDisassemblerLib: fix incorrect comparison

[PATCH EDK2 v1 0/1] ArmPkg/ArmDisassemblerLib: fix incorrect comparison

[wenyi,xie]

Main Changes :
As shift = (OpCode >> 5) & 0x3, shift will never be larger than 0x3,
so the comparison between shift and 0x12 will always be false. The right
shift type of ASR is 0x2, so 0x12 should to changed to 0x2.

Wenyi Xie (1):
  ArmPkg/ArmDisassemblerLib: fix incorrect comparison

 ArmPkg/Library/ArmDisassemblerLib/ArmDisassembler.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

-- 
2.20.1.windows.1

[PATCH EDK2 v1 1/1] ArmPkg/ArmDisassemblerLib: fix incorrect comparison

[wenyi,xie]

As shift = (OpCode >> 5) & 0x3, shift will never be larger than 0x3,
so the comparison between shift and 0x12 will always be false. The right
shift type of ASR is 0x2.

Cc: Leif Lindholm <leif@nuviainc.com>
Cc: Ard Biesheuvel <ard.biesheuvel@arm.com>
Signed-off-by: Wenyi Xie <xiewenyi2@huawei.com>
---
 ArmPkg/Library/ArmDisassemblerLib/ArmDisassembler.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/ArmPkg/Library/ArmDisassemblerLib/ArmDisassembler.c b/ArmPkg/Library/ArmDisassemblerLib/ArmDisassembler.c
index b4f0f8dbbfc9..d206cf4ea908 100644
--- a/ArmPkg/Library/ArmDisassemblerLib/ArmDisassembler.c
+++ b/ArmPkg/Library/ArmDisassemblerLib/ArmDisassembler.c
@@ -240,7 +240,7 @@ DisassembleArmInstruction (
           if (shift_imm == 0) {
             shift_imm = 32;
           }
-        } else if (shift == 0x12) {
+        } else if (shift == 0x2) {
           Type = "ASR";
         } else if (shift_imm == 0) {
           AsciiSPrint (&Buf[Index], Size - Index, "[%a, #%a%a, %a, RRX]%a", gReg[Rn], SIGN (U), gReg[Rm], WRITE (W));
@@ -270,7 +270,7 @@ DisassembleArmInstruction (
           if (shift_imm == 0) {
             shift_imm = 32;
           }
-        } else if (shift == 0x12) {
+        } else if (shift == 0x2) {
           Type = "ASR";
         } else if (shift_imm == 0) {
           AsciiSPrint (&Buf[Index], Size - Index, "[%a], #%a%a, %a, RRX", gReg[Rn], SIGN (U), gReg[Rm]);
-- 
2.20.1.windows.1

Re: [edk2-devel] [PATCH EDK2 v1 1/1] ArmPkg/ArmDisassemblerLib: fix incorrect comparison

[Leif Lindholm]

On Tue, Dec 08, 2020 at 21:07:49 +0800, wenyi,xie via groups.io wrote:
> As shift = (OpCode >> 5) & 0x3, shift will never be larger than 0x3,
> so the comparison between shift and 0x12 will always be false. The right
> shift type of ASR is 0x2.

Whoops[tm].

> Cc: Leif Lindholm <leif@nuviainc.com>
> Cc: Ard Biesheuvel <ard.biesheuvel@arm.com>
> Signed-off-by: Wenyi Xie <xiewenyi2@huawei.com>

Reviewed-by: Leif Lindholm <leif@nuviainc.com>
Pushed as 8e4cb8fbceb8.

Thanks!

> ---
>  ArmPkg/Library/ArmDisassemblerLib/ArmDisassembler.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/ArmPkg/Library/ArmDisassemblerLib/ArmDisassembler.c b/ArmPkg/Library/ArmDisassemblerLib/ArmDisassembler.c
> index b4f0f8dbbfc9..d206cf4ea908 100644
> --- a/ArmPkg/Library/ArmDisassemblerLib/ArmDisassembler.c
> +++ b/ArmPkg/Library/ArmDisassemblerLib/ArmDisassembler.c
> @@ -240,7 +240,7 @@ DisassembleArmInstruction (
>            if (shift_imm == 0) {
>              shift_imm = 32;
>            }
> -        } else if (shift == 0x12) {
> +        } else if (shift == 0x2) {
>            Type = "ASR";
>          } else if (shift_imm == 0) {
>            AsciiSPrint (&Buf[Index], Size - Index, "[%a, #%a%a, %a, RRX]%a", gReg[Rn], SIGN (U), gReg[Rm], WRITE (W));
> @@ -270,7 +270,7 @@ DisassembleArmInstruction (
>            if (shift_imm == 0) {
>              shift_imm = 32;
>            }
> -        } else if (shift == 0x12) {
> +        } else if (shift == 0x2) {
>            Type = "ASR";
>          } else if (shift_imm == 0) {
>            AsciiSPrint (&Buf[Index], Size - Index, "[%a], #%a%a, %a, RRX", gReg[Rn], SIGN (U), gReg[Rm]);
> -- 
> 2.20.1.windows.1
> 
> 
> 
> 
> 
>