From 199031b2b0233652ad5d5fdf73f0f44c0f264d55 Mon Sep 17 00:00:00 2001
From: Pierre Gondois <Pierre.Gondois@arm.com>
Date: Fri, 28 Oct 2022 17:32:53 +0200
Subject: [PATCH] SecurityPkg/RngDxe: Documentation/include/parameter cleanup

This patch:
-Update RngGetBytes() documentation to align the function
 definition and declaration.
-Improve input parameter checking. Even though 'This'
 it is not used, the parameter should always point to the
 current EFI_RNG_PROTOCOL.
-Removes TimerLib inclusion as unused.

Signed-off-by: Pierre Gondois <pierre.gondois@arm.com>
Acked-by: Jiewen Yao <jiewen.yao@intel.com>
---
 SecurityPkg/RandomNumberGenerator/RngDxe/AArch64/RngDxe.c | 3 +--
 SecurityPkg/RandomNumberGenerator/RngDxe/Rand/RngDxe.c    | 2 +-
 SecurityPkg/RandomNumberGenerator/RngDxe/RngDxe.c         | 3 +--
 3 files changed, 3 insertions(+), 5 deletions(-)

diff --git a/SecurityPkg/RandomNumberGenerator/RngDxe/AArch64/RngDxe.c b/SecurityPkg/RandomNumberGenerator/RngDxe/AArch64/RngDxe.c
index 6d989f7ea3..f9c740d761 100644
--- a/SecurityPkg/RandomNumberGenerator/RngDxe/AArch64/RngDxe.c
+++ b/SecurityPkg/RandomNumberGenerator/RngDxe/AArch64/RngDxe.c
@@ -23,7 +23,6 @@
 #include <Library/BaseLib.h>
 #include <Library/BaseMemoryLib.h>
 #include <Library/UefiBootServicesTableLib.h>
-#include <Library/TimerLib.h>
 #include <Protocol/Rng.h>
 
 #include "RngDxeInternals.h"
@@ -61,7 +60,7 @@ RngGetRNG (
 {
   EFI_STATUS  Status;
 
-  if ((RNGValueLength == 0) || (RNGValue == NULL)) {
+  if ((This == NULL) || (RNGValueLength == 0) || (RNGValue == NULL)) {
     return EFI_INVALID_PARAMETER;
   }
 
diff --git a/SecurityPkg/RandomNumberGenerator/RngDxe/Rand/RngDxe.c b/SecurityPkg/RandomNumberGenerator/RngDxe/Rand/RngDxe.c
index b2d2236380..8f5d8e740f 100644
--- a/SecurityPkg/RandomNumberGenerator/RngDxe/Rand/RngDxe.c
+++ b/SecurityPkg/RandomNumberGenerator/RngDxe/Rand/RngDxe.c
@@ -59,7 +59,7 @@ RngGetRNG (
 {
   EFI_STATUS  Status;
 
-  if ((RNGValueLength == 0) || (RNGValue == NULL)) {
+  if ((This == NULL) || (RNGValueLength == 0) || (RNGValue == NULL)) {
     return EFI_INVALID_PARAMETER;
   }
 
diff --git a/SecurityPkg/RandomNumberGenerator/RngDxe/RngDxe.c b/SecurityPkg/RandomNumberGenerator/RngDxe/RngDxe.c
index 6608ca8804..d7905a7f4d 100644
--- a/SecurityPkg/RandomNumberGenerator/RngDxe/RngDxe.c
+++ b/SecurityPkg/RandomNumberGenerator/RngDxe/RngDxe.c
@@ -23,7 +23,6 @@ SPDX-License-Identifier: BSD-2-Clause-Patent
 #include <Library/BaseMemoryLib.h>
 #include <Library/UefiBootServicesTableLib.h>
 #include <Library/RngLib.h>
-#include <Library/TimerLib.h>
 #include <Protocol/Rng.h>
 
 #include "RngDxeInternals.h"
@@ -72,7 +71,7 @@ RngDriverEntry (
 }
 
 /**
-  Calls RDRAND to fill a buffer of arbitrary size with random bytes.
+  Runs CPU RNG instruction to fill a buffer of arbitrary size with random bytes.
 
   @param[in]   Length        Size of the buffer, in bytes,  to fill with.
   @param[out]  RandBuffer    Pointer to the buffer to store the random result.