Re: [patch V3] MdeModulePkg/ReportStatusCodeLib: Avoid using AllocatePool if possible

["Zeng, Star" <star.zeng@intel.com>]

Hi Dandan,

/DxeReportStatusCodeLib/ReportStatusCodeLib.c:

The " Retrieve the current TPL " code block is not needed also when using stack buffer, so it can be also moved to else condition.

And the code block below is redundant, so it can be removed.
  if (StatusCodeData == NULL) {
    //
    // If a buffer could not be allocated, then see if the local variable Buffer can be used
    //
    if (ExtendedDataSize > (MAX_EXTENDED_DATA_SIZE - sizeof (EFI_STATUS_CODE_DATA))) {
      //
      // The local variable Buffer not large enough to hold the extended data associated
      // with the status code being reported.
      //
      DEBUG ((EFI_D_ERROR, "Status code extended data is too large to be reported!\n"));
      return EFI_OUT_OF_RESOURCES;
    }
    StatusCodeData = (EFI_STATUS_CODE_DATA  *)Buffer;
  }

The code for /RuntimeDxeReportStatusCodeLib/ReportStatusCodeLib.c can be also refined.

To be easily understand, check https://github.com/lzeng14/edk2/tree/ReportStatusCode for reference.


Thanks,
Star
-----Original Message-----
From: edk2-devel [mailto:edk2-devel-bounces@lists.01.org] On Behalf Of Dandan Bi
Sent: Monday, February 18, 2019 10:43 AM
To: edk2-devel@lists.01.org
Cc: Max Knutsen <maknutse@microsoft.com>; Wu, Hao A <hao.a.wu@intel.com>; Michael Turner <Michael.Turner@microsoft.com>; Gao, Liming <liming.gao@intel.com>; Zeng, Star <star.zeng@intel.com>
Subject: [edk2] [patch V3] MdeModulePkg/ReportStatusCodeLib: Avoid using AllocatePool if possible

From: Max Knutsen <maknutse@microsoft.com>

REF: https://bugzilla.tianocore.org/show_bug.cgi?id=1114

V2: simplify the code logic.
update
if (!mHaveExitedBootServices &&
  (StatusCodeData != (EFI_STATUS_CODE_DATA *) StatusCodeBuffer)) {
  gBS->FreePool (StatusCodeData);
}
to
if (StatusCodeData != (EFI_STATUS_CODE_DATA *) StatusCodeBuffer) {
  gBS->FreePool (StatusCodeData);
}

V3:
And the code below into the else condition (stack buffer is not enough) in /DxeReportStatusCodeLib/ReportStatusCodeLib.c

  if (gBS == NULL || gBS->AllocatePool == NULL || gBS->FreePool == NULL) {
    return EFI_UNSUPPORTED;
  }

When report status code with ExtendedData data, and the extended data can fit in the local static buffer, there is no need to use AllocatePool to hold the ExtendedData data.

This patch is just to do the enhancement to avoid using AllocatePool.

Cc: Star Zeng <star.zeng@intel.com>
Cc: Jian J Wang <jian.j.wang@intel.com>
Cc: Hao Wu <hao.a.wu@intel.com>
Cc: Michael Turner <Michael.Turner@microsoft.com>
Cc: Liming Gao <liming.gao@intel.com>
Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: Dandan Bi <dandan.bi@intel.com>
---
 .../DxeReportStatusCodeLib/ReportStatusCodeLib.c  | 15 +++++++++------
 .../ReportStatusCodeLib.c                         |  9 +++++++--
 2 files changed, 16 insertions(+), 8 deletions(-)

diff --git a/MdeModulePkg/Library/DxeReportStatusCodeLib/ReportStatusCodeLib.c b/MdeModulePkg/Library/DxeReportStatusCodeLib/ReportStatusCodeLib.c
index b28dc5c3bb..3bca0a94ee 100644
--- a/MdeModulePkg/Library/DxeReportStatusCodeLib/ReportStatusCodeLib.c
+++ b/MdeModulePkg/Library/DxeReportStatusCodeLib/ReportStatusCodeLib.c
@@ -494,24 +494,27 @@ ReportStatusCodeEx (
   UINT64                Buffer[(MAX_EXTENDED_DATA_SIZE / sizeof (UINT64)) + 1];
 
   ASSERT (!((ExtendedData == NULL) && (ExtendedDataSize != 0)));
   ASSERT (!((ExtendedData != NULL) && (ExtendedDataSize == 0)));
 
-  if (gBS == NULL || gBS->AllocatePool == NULL || gBS->FreePool == NULL) {
-    return EFI_UNSUPPORTED;
-  }
-
   //
   // Retrieve the current TPL
   //
   Tpl = gBS->RaiseTPL (TPL_HIGH_LEVEL);
   gBS->RestoreTPL (Tpl);
 
   StatusCodeData = NULL;
-  if (Tpl <= TPL_NOTIFY) {
+  if (ExtendedDataSize <= (MAX_EXTENDED_DATA_SIZE - sizeof (EFI_STATUS_CODE_DATA))) {
+    //
+    // Use Buffer instead of allocating if possible.
+    //
+    StatusCodeData = (EFI_STATUS_CODE_DATA *)Buffer;  } else if (gBS == 
+ NULL || gBS->AllocatePool == NULL || gBS->FreePool == NULL) {
+    return EFI_UNSUPPORTED;
+  } else if (Tpl <= TPL_NOTIFY){
     //
-    // Allocate space for the Status Code Header and its buffer
+    // If Buffer is not big enough, allocate space for the Status Code 
+ Header and its buffer
     //
     gBS->AllocatePool (EfiBootServicesData, sizeof (EFI_STATUS_CODE_DATA) + ExtendedDataSize, (VOID **)&StatusCodeData);
   }
 
   if (StatusCodeData == NULL) {
diff --git a/MdeModulePkg/Library/RuntimeDxeReportStatusCodeLib/ReportStatusCodeLib.c b/MdeModulePkg/Library/RuntimeDxeReportStatusCodeLib/ReportStatusCodeLib.c
index b73103517a..75e2f88ad2 100644
--- a/MdeModulePkg/Library/RuntimeDxeReportStatusCodeLib/ReportStatusCodeLib.c
+++ b/MdeModulePkg/Library/RuntimeDxeReportStatusCodeLib/ReportStatusCod
+++ eLib.c
@@ -635,11 +635,14 @@ ReportStatusCodeEx (
   if (mHaveExitedBootServices) {
     if (sizeof (EFI_STATUS_CODE_DATA) + ExtendedDataSize > MAX_EXTENDED_DATA_SIZE) {
       return EFI_OUT_OF_RESOURCES;
     }
     StatusCodeData = (EFI_STATUS_CODE_DATA *) StatusCodeBuffer;
-  } else  {
+  } else if (sizeof (EFI_STATUS_CODE_DATA) + ExtendedDataSize > MAX_EXTENDED_DATA_SIZE) {
+    //
+    // Only use AllocatePool for larger ExtendedData.
+    //
     if (gBS == NULL || gBS->AllocatePool == NULL || gBS->FreePool == NULL) {
       return EFI_UNSUPPORTED;
     }
 
     //
@@ -648,10 +651,12 @@ ReportStatusCodeEx (
     StatusCodeData = NULL;
     gBS->AllocatePool (EfiBootServicesData, sizeof (EFI_STATUS_CODE_DATA) + ExtendedDataSize, (VOID **)&StatusCodeData);
     if (StatusCodeData == NULL) {
       return EFI_OUT_OF_RESOURCES;
     }
+  } else {
+    StatusCodeData = (EFI_STATUS_CODE_DATA *) StatusCodeBuffer;
   }
 
   //
   // Fill in the extended data header
   //
@@ -678,11 +683,11 @@ ReportStatusCodeEx (
   Status = InternalReportStatusCode (Type, Value, Instance, CallerId, StatusCodeData);
 
   //
   // Free the allocated buffer
   //
-  if (!mHaveExitedBootServices) {
+  if (StatusCodeData != (EFI_STATUS_CODE_DATA *) StatusCodeBuffer) {
     gBS->FreePool (StatusCodeData);
   }
 
   return Status;
 }
--
2.18.0.windows.1

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