Re: [PATCH] ShellPkg/editor: Fix system hang when console max column > 200

["Carsey, Jaben" <jaben.carsey@intel.com>]

Reviewed-by: Jaben Carsey <jaben.carsey@intel.com>

> -----Original Message-----
> From: Ni, Ruiyu
> Sent: Wednesday, October 18, 2017 11:15 PM
> To: edk2-devel@lists.01.org
> Cc: Carsey, Jaben <jaben.carsey@intel.com>
> Subject: [PATCH] ShellPkg/editor: Fix system hang when console max column
> > 200
> Importance: High
> 
> EditorClearLine() assumes the console max column is less than 200.
> When the max column is bigger than 200, the code incorrectly
> modifies the content out side of Line buffer.
> It may cause system hang or reset.
> 
> The patch changes the function to print several times when
> the max column is bigger than 200.
> 
> Contributed-under: TianoCore Contribution Agreement 1.1
> Signed-off-by: Ruiyu Ni <ruiyu.ni@intel.com>
> Cc: Jaben Carsey <jaben.carsey@intel.com>
> ---
>  .../UefiShellDebug1CommandsLib.c                   | 31 +++++++++++++---------
>  1 file changed, 19 insertions(+), 12 deletions(-)
> 
> diff --git
> a/ShellPkg/Library/UefiShellDebug1CommandsLib/UefiShellDebug1Comman
> dsLib.c
> b/ShellPkg/Library/UefiShellDebug1CommandsLib/UefiShellDebug1Comman
> dsLib.c
> index 8e2141bf43..d26d08f95c 100644
> ---
> a/ShellPkg/Library/UefiShellDebug1CommandsLib/UefiShellDebug1Comman
> dsLib.c
> +++
> b/ShellPkg/Library/UefiShellDebug1CommandsLib/UefiShellDebug1Comman
> dsLib.c
> @@ -185,6 +185,7 @@ EditorClearLine (
>    IN UINTN LastRow
>    )
>  {
> +  UINTN  Col;
>    CHAR16 Line[200];
> 
>    if (Row == 0) {
> @@ -193,22 +194,28 @@ EditorClearLine (
> 
>    //
>    // prepare a blank line
> +  // If max column is larger, split to multiple prints.
>    //
> -  SetMem16(Line, LastCol*sizeof(CHAR16), L' ');
> -
> -  if (Row == LastRow) {
> +  SetMem16 (Line, sizeof (Line), L' ');
> +  Line[ARRAY_SIZE (Line) - 1] = CHAR_NULL;
> +
> +  for (Col = 1; Col <= LastCol; Col += ARRAY_SIZE (Line) - 1) {
> +    if (Col + ARRAY_SIZE (Line) - 1 > LastCol) {
> +      if (Row == LastRow) {
> +        //
> +        // if CHAR_NULL is still at position LastCol, it will cause first line error
> +        //
> +        Line[(LastCol % (ARRAY_SIZE (Line) - 1)) - 1] = CHAR_NULL;
> +      } else {
> +        Line[LastCol % (ARRAY_SIZE (Line) - 1)] = CHAR_NULL;
> +      }
> +    }
> +
>      //
> -    // if CHAR_NULL is still at position 80, it will cause first line error
> +    // print out the blank line
>      //
> -    Line[LastCol - 1] = CHAR_NULL;
> -  } else {
> -    Line[LastCol] = CHAR_NULL;
> +    ShellPrintEx ((INT32) Col - 1, (INT32) Row - 1, Line);
>    }
> -
> -  //
> -  // print out the blank line
> -  //
> -  ShellPrintEx (0, ((INT32)Row) - 1, Line);
>  }
> 
>  /**
> --
> 2.12.2.windows.2