From: Ruiyu Ni <ruiyu.ni@intel.com>
Date: Thu, 11 Oct 2018 07:51:45 +0000 (+0800)
Subject: ShellPkg/dmem: Only dump sizeof (EFI_SYSTEM_TABLE) bytes for gST
X-Git-Tag: edk2-stable201903~749
X-Git-Url: https://git.proxmox.com/?p=mirror_edk2.git;a=commitdiff_plain;h=f1a7d73a6880471b2f006044995276f65f44428a

ShellPkg/dmem: Only dump sizeof (EFI_SYSTEM_TABLE) bytes for gST

REF: https://bugzilla.tianocore.org/show_bug.cgi?id=1236

When "dmem" runs without additional arguments, it dumps the memory
content of EFI_SYSTEM_TABLE. But today's implementation dumps 512
bytes. It's not correct because sizeof (EFI_SYSTEM_TABLE) is less
than 512, the 512-read causes page fault exception in a heap-guard
enabled environment.

The patch changes the implementation to only dump
sizeof (EFI_SYSTEM_TABLE) bytes for gST.

Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: Ruiyu Ni <ruiyu.ni@intel.com>
Cc: Jaben Carsey <jaben.carsey@intel.com>
Reviewed-by: Jim Dailey <jim_dailey@.com>
---

diff --git a/ShellPkg/Library/UefiShellDebug1CommandsLib/Dmem.c b/ShellPkg/Library/UefiShellDebug1CommandsLib/Dmem.c
index f38593a9e9..a4c18c9b68 100644
--- a/ShellPkg/Library/UefiShellDebug1CommandsLib/Dmem.c
+++ b/ShellPkg/Library/UefiShellDebug1CommandsLib/Dmem.c
@@ -149,7 +149,7 @@ ShellCommandRunDmem (
       Temp1 = ShellCommandLineGetRawValue(Package, 1);
       if (Temp1 == NULL) {
         Address = gST;
-        Size = 512;
+        Size    = sizeof (*gST);
       } else {
         if (!ShellIsHexOrDecimalNumber(Temp1, TRUE, FALSE) || EFI_ERROR(ShellConvertStringToUint64(Temp1, (UINT64*)&Address, TRUE, FALSE))) {
           ShellPrintHiiEx(-1, -1, NULL, STRING_TOKEN (STR_GEN_PARAM_INV), gShellDebug1HiiHandle, L"dmem", Temp1);