Re: [PATCH v2 5/5] ArmPkg/DefaultExceptionHandlerLib: use console if available

[Laszlo Ersek <lersek@redhat.com>]

On 01/15/19 09:23, Ard Biesheuvel wrote:
> Print the minimal 'exception occurred' message to the console instead
> of straight to the serial port if the console is available. This makes
> such messages visible on systems where the console is graphical and
> the serial is not connected.
> 
> Contributed-under: TianoCore Contribution Agreement 1.1
> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
> Reviewed-by: Leif Lindholm <leif.lindholm@linaro.org>
> ---
>  ArmPkg/Library/DefaultExceptionHandlerLib/AArch64/DefaultExceptionHandler.c | 12 ++++++++++--
>  ArmPkg/Library/DefaultExceptionHandlerLib/Arm/DefaultExceptionHandler.c     |  7 ++++++-
>  ArmPkg/Library/DefaultExceptionHandlerLib/DefaultExceptionHandlerLib.inf    |  1 +
>  3 files changed, 17 insertions(+), 3 deletions(-)

Please consider updating the following, before pushing the patch:

> diff --git a/ArmPkg/Library/DefaultExceptionHandlerLib/AArch64/DefaultExceptionHandler.c b/ArmPkg/Library/DefaultExceptionHandlerLib/AArch64/DefaultExceptionHandler.c
> index 1024bf48c63d..362acd5ba6d2 100644
> --- a/ArmPkg/Library/DefaultExceptionHandlerLib/AArch64/DefaultExceptionHandler.c
> +++ b/ArmPkg/Library/DefaultExceptionHandlerLib/AArch64/DefaultExceptionHandler.c
> @@ -22,6 +22,7 @@
>  #include <Library/PrintLib.h>
>  #include <Library/ArmDisassemblerLib.h>
>  #include <Library/SerialPortLib.h>
> +#include <Library/UefiBootServicesTableLib.h>
>  
>  #include <Guid/DebugImageInfoTable.h>
>  #include <Protocol/DebugSupport.h>
> @@ -159,14 +160,21 @@ DefaultExceptionHandler (
>    INT32  Offset;
>  
>    if (mRecursiveException) {
> -    CharCount = AsciiSPrint (Buffer, sizeof (Buffer),"\nRecursive exception occurred while dumping the CPU state\n");
> -    SerialPortWrite ((UINT8 *) Buffer, CharCount);
> +    STATIC CHAR8 CONST Message[] = "\nRecursive exception occurred while dumping the CPU state\n";
> +
> +    SerialPortWrite ((UINT8 *)Message, AsciiStrLen (Message));

(1) A micro-optimization could be (sizeof Message - 1) rather than
AsciiStrLen (Message), but it's mostly irrelevant.

> +    if (gST->ConOut != NULL) {
> +      AsciiPrint (Message);
> +    }
>      CpuDeadLoop ();
>    }
>    mRecursiveException = TRUE;
>  
>    CharCount = AsciiSPrint (Buffer,sizeof (Buffer),"\n\n%a Exception at 0x%016lx\n", gExceptionTypeString[ExceptionType], SystemContext.SystemContextAArch64->ELR);
>    SerialPortWrite ((UINT8 *) Buffer, CharCount);
> +  if (gST->ConOut != NULL) {
> +    AsciiPrint (Buffer);
> +  }
>  
>    DEBUG_CODE_BEGIN ();
>      CHAR8  *Pdb, *PrevPdb;
> diff --git a/ArmPkg/Library/DefaultExceptionHandlerLib/Arm/DefaultExceptionHandler.c b/ArmPkg/Library/DefaultExceptionHandlerLib/Arm/DefaultExceptionHandler.c
> index cc79cb2fa301..a79f73725aed 100644
> --- a/ArmPkg/Library/DefaultExceptionHandlerLib/Arm/DefaultExceptionHandler.c
> +++ b/ArmPkg/Library/DefaultExceptionHandlerLib/Arm/DefaultExceptionHandler.c
> @@ -21,6 +21,7 @@
>  #include <Library/PrintLib.h>
>  #include <Library/ArmDisassemblerLib.h>
>  #include <Library/SerialPortLib.h>
> +#include <Library/UefiBootServicesTableLib.h>
>  
>  #include <Guid/DebugImageInfoTable.h>
>  
> @@ -194,7 +195,11 @@ DefaultExceptionHandler (
>  
>    CharCount = AsciiSPrint (Buffer,sizeof (Buffer),"\n%a Exception PC at 0x%08x  CPSR 0x%08x ",
>           gExceptionTypeString[ExceptionType], SystemContext.SystemContextArm->PC, SystemContext.SystemContextArm->CPSR);
> -  SerialPortWrite ((UINT8 *) Buffer, CharCount);
> +  if (gST->ConOut != NULL) {
> +    AsciiPrint (Buffer);
> +  } else {
> +    SerialPortWrite ((UINT8 *)Buffer, CharCount);
> +  }

(2) I think the "serial PLUS console" reporting applies to the 32-bit
lib instance as well, so I assume not updating this from v1 was an
oversight.

>  
>    DEBUG_CODE_BEGIN ();
>      CHAR8   *Pdb;
> diff --git a/ArmPkg/Library/DefaultExceptionHandlerLib/DefaultExceptionHandlerLib.inf b/ArmPkg/Library/DefaultExceptionHandlerLib/DefaultExceptionHandlerLib.inf
> index 7609f82d89a1..6bc48714c9dc 100644
> --- a/ArmPkg/Library/DefaultExceptionHandlerLib/DefaultExceptionHandlerLib.inf
> +++ b/ArmPkg/Library/DefaultExceptionHandlerLib/DefaultExceptionHandlerLib.inf
> @@ -42,6 +42,7 @@ [LibraryClasses]
>    PeCoffGetEntryPointLib
>    ArmDisassemblerLib
>    SerialPortLib
> +  UefiBootServicesTableLib
>  
>  [Guids]
>    gEfiDebugImageInfoTableGuid
> 

With (2) updated, and regardless of (1):

Acked-by: Laszlo Ersek <lersek@redhat.com>

Thanks!
Laszlo