ShellPkg: Refine the logic about allocating memory for variable name and data.

[mirror_edk2.git] / ShellPkg / Application / Shell / ShellEnvVar.c

diff --git a/ShellPkg/Application/Shell/ShellEnvVar.c b/ShellPkg/Application/Shell/ShellEnvVar.c
index b94711142af6c3ff4532ed1b6127e2b70eea9e31..de09174c624d6b0c736993ca4f3e48d7ca55cefc 100644 (file)
--- a/ShellPkg/Application/Shell/ShellEnvVar.c
+++ b/ShellPkg/Application/Shell/ShellEnvVar.c
@@ -1,7 +1,7 @@
 /** @file\r
   function declarations for shell environment functions.\r
 \r
-  Copyright (c) 2009 - 2011, Intel Corporation. All rights reserved.<BR>\r
+  Copyright (c) 2009 - 2015, Intel Corporation. All rights reserved.<BR>\r
   This program and the accompanying materials\r
   are licensed and made available under the terms and conditions of the BSD License\r
   which accompanies this distribution.  The full text of the license may be found at\r
@@ -14,6 +14,9 @@
 \r
 #include "Shell.h"\r
 \r
+#define INIT_NAME_BUFFER_SIZE  128\r
+#define INIT_DATA_BUFFER_SIZE  1024\r
+\r
 /**\r
   Reports whether an environment variable is Volatile or Non-Volatile.\r
 \r
@@ -125,59 +128,72 @@ GetEnvironmentVariableList(
 {\r
   CHAR16            *VariableName;\r
   UINTN             NameSize;\r
-  UINT64            MaxStorSize;\r
-  UINT64            RemStorSize;\r
-  UINT64            MaxVarSize;\r
+  UINTN             NameBufferSize;\r
   EFI_STATUS        Status;\r
   EFI_GUID          Guid;\r
   UINTN             ValSize;\r
+  UINTN             ValBufferSize;\r
   ENV_VAR_LIST      *VarList;\r
 \r
   if (ListHead == NULL) {\r
     return (EFI_INVALID_PARAMETER);\r
   }\r
-\r
-  if (gRT->Hdr.Revision >= EFI_2_00_SYSTEM_TABLE_REVISION) {\r
-    Status = gRT->QueryVariableInfo(EFI_VARIABLE_NON_VOLATILE|EFI_VARIABLE_BOOTSERVICE_ACCESS, &MaxStorSize, &RemStorSize, &MaxVarSize);\r
-    if (EFI_ERROR(Status)) {\r
-      return (Status);\r
-    }\r
-  } else {\r
-    Status = EFI_SUCCESS;\r
-    MaxVarSize = 16384;\r
-  }\r
-\r
-  NameSize = (UINTN)MaxVarSize;\r
-  VariableName = AllocateZeroPool(NameSize);\r
+  \r
+  Status = EFI_SUCCESS;\r
+  \r
+  ValBufferSize = INIT_DATA_BUFFER_SIZE;\r
+  NameBufferSize = INIT_NAME_BUFFER_SIZE;\r
+  VariableName = AllocateZeroPool(NameBufferSize);\r
   if (VariableName == NULL) {\r
     return (EFI_OUT_OF_RESOURCES);\r
   }\r
   *VariableName = CHAR_NULL;\r
 \r
   while (!EFI_ERROR(Status)) {\r
-    NameSize = (UINTN)MaxVarSize;\r
+    NameSize = NameBufferSize;\r
     Status = gRT->GetNextVariableName(&NameSize, VariableName, &Guid);\r
     if (Status == EFI_NOT_FOUND){\r
       Status = EFI_SUCCESS;\r
       break;\r
+    } else if (Status == EFI_BUFFER_TOO_SMALL) {\r
+      NameBufferSize = NameSize > NameBufferSize * 2 ? NameSize : NameBufferSize * 2;\r
+      SHELL_FREE_NON_NULL(VariableName);\r
+      VariableName = AllocateZeroPool(NameBufferSize);\r
+      if (VariableName == NULL) {\r
+        Status = EFI_OUT_OF_RESOURCES;\r
+        break;\r
+      }\r
+      NameSize = NameBufferSize;\r
+      Status = gRT->GetNextVariableName(&NameSize, VariableName, &Guid);\r
     }\r
+    \r
     if (!EFI_ERROR(Status) && CompareGuid(&Guid, &gShellVariableGuid)){\r
       VarList = AllocateZeroPool(sizeof(ENV_VAR_LIST));\r
       if (VarList == NULL) {\r
         Status = EFI_OUT_OF_RESOURCES;\r
       } else {\r
-        ValSize = 0;\r
+        ValSize = ValBufferSize;\r
+        VarList->Val = AllocateZeroPool(ValSize);\r
+        if (VarList->Val == NULL) {\r
+            SHELL_FREE_NON_NULL(VarList);\r
+            Status = EFI_OUT_OF_RESOURCES;\r
+            break;\r
+        }\r
         Status = SHELL_GET_ENVIRONMENT_VARIABLE_AND_ATTRIBUTES(VariableName, &VarList->Atts, &ValSize, VarList->Val);\r
         if (Status == EFI_BUFFER_TOO_SMALL){\r
-          VarList->Val = AllocateZeroPool(ValSize);\r
+          ValBufferSize = ValSize > ValBufferSize * 2 ? ValSize : ValBufferSize * 2;\r
+          SHELL_FREE_NON_NULL (VarList->Val);\r
+          VarList->Val = AllocateZeroPool(ValBufferSize);\r
           if (VarList->Val == NULL) {\r
             SHELL_FREE_NON_NULL(VarList);\r
             Status = EFI_OUT_OF_RESOURCES;\r
-          } else {\r
-            Status = SHELL_GET_ENVIRONMENT_VARIABLE_AND_ATTRIBUTES(VariableName, &VarList->Atts, &ValSize, VarList->Val);\r
+            break;\r
           }\r
+          \r
+          ValSize = ValBufferSize;\r
+          Status = SHELL_GET_ENVIRONMENT_VARIABLE_AND_ATTRIBUTES(VariableName, &VarList->Atts, &ValSize, VarList->Val);\r
         }\r
-        if (!EFI_ERROR(Status) && VarList != NULL) {\r
+        if (!EFI_ERROR(Status)) {\r
           VarList->Key = AllocateCopyPool(StrSize(VariableName), VariableName);\r
           if (VarList->Key == NULL) {\r
             SHELL_FREE_NON_NULL(VarList->Val);\r
@@ -186,11 +202,14 @@ GetEnvironmentVariableList(
           } else {\r
             InsertTailList(ListHead, &VarList->Link);\r
           }\r
+        } else {\r
+          SHELL_FREE_NON_NULL(VarList->Val);\r
+          SHELL_FREE_NON_NULL(VarList);\r
         }\r
-      }\r
+      } // if (VarList == NULL) ... else ...\r
     } // compare guid\r
   } // while\r
-  FreePool(VariableName);\r
+  SHELL_FREE_NON_NULL (VariableName);\r
 \r
   if (EFI_ERROR(Status)) {\r
     FreeEnvironmentVariableList(ListHead);\r