Re: [edk2-devel] [Patch] ShellPkg/AcpiView: Fix IA32 link error

["Sami Mujawar" <sami.mujawar@arm.com>]

Hi Mike,

Since LocalityCount is 64-bit wide the SLIT validation code could possibly end up in an infinite loop. I am not aware of a platform that has a large enough LocalityCount to hit this condition. However, would it be good to have a check that limits the validation to MAX_UINT32?

e.g. Something like
if  (LocalityCount < MAX_UINT32) {
  // Validate
  for (Count = 0; Count < LocalityCount; Count++) {
    for (Index = 0; Index < LocalityCount; Index++) {
  ...
} else {
  Print (L"INFO: Skipping validation of System Localities as locality count is > MAX_UINT32\n");
}

Regards,

Sami Mujawar

-----Original Message-----
From: devel@edk2.groups.io <devel@edk2.groups.io> On Behalf Of Michael D Kinney via Groups.Io
Sent: 10 July 2019 11:35 PM
To: devel@edk2.groups.io
Cc: Jaben Carsey <jaben.carsey@intel.com>; Ray Ni <ray.ni@intel.com>; Zhichao Gao <zhichao.gao@intel.com>
Subject: [edk2-devel] [Patch] ShellPkg/AcpiView: Fix IA32 link error

https://bugzilla.tianocore.org/show_bug.cgi?id=1970

Update local variable in ParseAcpiSlot() to be UINT32 instead of UINT64 to avoid 64-bit multiply operation in the SLIT_ELEMENT() macro.

Cc: Jaben Carsey <jaben.carsey@intel.com>
Cc: Ray Ni <ray.ni@intel.com>
Cc: Zhichao Gao <zhichao.gao@intel.com>
Signed-off-by: Michael D Kinney <michael.d.kinney@intel.com>
---
 .../UefiShellAcpiViewCommandLib/Parsers/Slit/SlitParser.c     | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/ShellPkg/Library/UefiShellAcpiViewCommandLib/Parsers/Slit/SlitParser.c b/ShellPkg/Library/UefiShellAcpiViewCommandLib/Parsers/Slit/SlitParser.c
index 1f9dac66ee..af85c9aa1c 100644
--- a/ShellPkg/Library/UefiShellAcpiViewCommandLib/Parsers/Slit/SlitParser.c
+++ b/ShellPkg/Library/UefiShellAcpiViewCommandLib/Parsers/Slit/SlitPars
+++ er.c
@@ -57,8 +57,8 @@ ParseAcpiSlit (
   )
 {
   UINT32 Offset;
-  UINT64 Count;
-  UINT64 Index;
+  UINT32 Count;
+  UINT32 Index;
   UINT64 LocalityCount;
   UINT8* LocalityPtr;
   CHAR16 Buffer[80];  // Used for AsciiName param of ParseAcpi
--
2.21.0.windows.1




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