01/01: [ROSLOAD]: Fix NX enabling

[Alex Ionescu]

https://git.reactos.org/?p=reactos.git;a=commitdiff;h=478348ead113ae5d5b5ea…

commit 478348ead113ae5d5b5eaf579b540f65339bebbd
Author:     Alex Ionescu <aionescu(a)gmail.com>
AuthorDate: Sun Jan 28 16:29:43 2018 +0100
Commit:     Alex Ionescu <aionescu(a)gmail.com>
CommitDate: Sun Jan 28 16:29:43 2018 +0100

    [ROSLOAD]: Fix NX enabling
    
    [ROSLOAD]: The IA32_MISC_ENABLE MSR bit actually _disables_ NX, so
    diabling the bit _enables_ NX.
    [ROSLOAD]: The MSR_XD_ENABLE_MASK is for the _high_ DWORD of the MSR
    (bit 34), not the low.
    [ROSLOAD]: Fix printf.
    [ENVIRON/ROSLOAD]: Switch to CPU_INFO structure instead of blindly using
    INT[4]. Revealed a bug in the PAE detection which was reading out of
    bounds.
---
 boot/environ/app/rosload/rosload.c | 39 ++++++++++++++++++++------------------
 boot/environ/include/bl.h          |  2 +-
 boot/environ/lib/misc/util.c       | 30 ++++++++++++++---------------
 boot/environ/lib/mm/i386/mmx86.c   |  6 +++---
 4 files changed, 40 insertions(+), 37 deletions(-)

diff --git a/boot/environ/app/rosload/rosload.c b/boot/environ/app/rosload/rosload.c
index 9120631a1f..3c51963251 100644
--- a/boot/environ/app/rosload/rosload.c
+++ b/boot/environ/app/rosload/rosload.c
@@ -9783,24 +9783,26 @@ OslpMain (
     _Out_ PULONG ReturnFlags
     )
 {
-    INT CpuInfo[4];
-    BOOLEAN NxDisabled;
+    CPU_INFO CpuInfo;
+    BOOLEAN NxEnabled;
     NTSTATUS Status;
     BOOLEAN ExecuteJump;
+    LARGE_INTEGER miscMsr;
 
     /* Check if the CPU supports NX */
-    BlArchCpuId(0x80000001, 0, CpuInfo);
-    if (!(CpuInfo[3] & 0x10000))
+    BlArchCpuId(0x80000001, 0, &CpuInfo);
+    if (!(CpuInfo.Edx & 0x10000))
     {
         /* It doesn't, check if this is Intel */
-        EfiPrintf(L"NX disabled: %d\r\n");
+        EfiPrintf(L"NX disabled: %lx\r\n", CpuInfo.Edx);
         if (BlArchGetCpuVendor() == CPU_INTEL)
         {
-            /* Then turn off the MSR feature for it */
-            EfiPrintf(L"NX being turned off\r\n");
-            __writemsr(MSR_IA32_MISC_ENABLE,
-                       __readmsr(MSR_IA32_MISC_ENABLE) & MSR_XD_ENABLE_MASK);
-            NxDisabled = TRUE;
+            /* Then turn off the MSR disable feature for it, enabling NX */
+            EfiPrintf(L"NX being turned on\r\n");
+            miscMsr.QuadPart = __readmsr(MSR_IA32_MISC_ENABLE);
+            miscMsr.HighPart &= MSR_XD_ENABLE_MASK;
+            __writemsr(MSR_IA32_MISC_ENABLE, miscMsr.QuadPart);
+            NxEnabled = TRUE;
         }
     }
 
@@ -9818,12 +9820,13 @@ OslpMain (
     /* Retore NX support */
     __writemsr(MSR_EFER, __readmsr(MSR_EFER) ^ MSR_NXE);
 
-    /* Did we disable NX? */
-    if (NxDisabled)
+    /* Did we manually enable NX? */
+    if (NxEnabled)
     {
-        /* Turn it back on */
-        __writemsr(MSR_IA32_MISC_ENABLE,
-                   __readmsr(MSR_IA32_MISC_ENABLE) | ~MSR_XD_ENABLE_MASK);
+        /* Turn it back off */
+        miscMsr.QuadPart = __readmsr(MSR_IA32_MISC_ENABLE);
+        miscMsr.HighPart |= ~MSR_XD_ENABLE_MASK;
+        __writemsr(MSR_IA32_MISC_ENABLE, miscMsr.QuadPart);
     }
 
     /* Go back */
@@ -9853,7 +9856,7 @@ OslMain (
     NTSTATUS Status;
     PBL_RETURN_ARGUMENTS ReturnArguments;
     PBL_APPLICATION_ENTRY AppEntry;
-    INT CpuInfo[4];
+    CPU_INFO CpuInfo;
     ULONG Flags;
 #ifdef DRAW_LOGO
     EFI_GRAPHICS_OUTPUT_BLT_PIXEL* gopBlt;
@@ -9887,10 +9890,10 @@ OslMain (
     if (BlArchIsCpuIdFunctionSupported(1))
     {
         /* Query CPU features */
-        BlArchCpuId(1, 0, CpuInfo);
+        BlArchCpuId(1, 0, &CpuInfo);
 
         /* Check if PAE is supported */
-        if (CpuInfo[4] & 0x40)
+        if (CpuInfo.Edx & 0x40)
         {
             EfiPrintf(L"PAE Supported, but won't be used\r\n");
         }
diff --git a/boot/environ/include/bl.h b/boot/environ/include/bl.h
index 7fa6c9667e..023e676d75 100644
--- a/boot/environ/include/bl.h
+++ b/boot/environ/include/bl.h
@@ -1666,7 +1666,7 @@ VOID
 BlArchCpuId (
     _In_ ULONG Function,
     _In_ ULONG SubFunction,
-    _Out_ INT* Result
+    _Out_ PCPU_INFO Result
     );
 
 CPU_VENDORS
diff --git a/boot/environ/lib/misc/util.c b/boot/environ/lib/misc/util.c
index d6e5459882..18f21cc2e9 100644
--- a/boot/environ/lib/misc/util.c
+++ b/boot/environ/lib/misc/util.c
@@ -904,12 +904,12 @@ BlArchGetPerformanceCounter (
     )
 {
 #if defined(_M_IX86) || defined(_M_X64)
-    INT CpuInfo[4];
+    CPU_INFO CpuInfo;
 
     /* Serialize with CPUID, if it exists */
     if (Archx86IsCpuidSupported())
     {
-        BlArchCpuId(0, 0, CpuInfo);
+        BlArchCpuId(0, 0, &CpuInfo);
     }
 
     /* Read the TSC */
@@ -924,12 +924,12 @@ VOID
 BlArchCpuId (
     _In_ ULONG Function,
     _In_ ULONG SubFunction,
-    _Out_ INT* Result
+    _Out_ PCPU_INFO Result
     )
 {
 #if defined(_M_IX86) || defined(_M_X64)
     /* Use the intrinsic */
-    __cpuidex(Result, Function, SubFunction);
+    __cpuidex((INT*)Result->AsUINT32, Function, SubFunction);
 #endif
 }
 
@@ -938,37 +938,37 @@ BlArchGetCpuVendor (
     VOID
     )
 {
-    INT CpuInfo[4];
+    CPU_INFO CpuInfo;
     INT Temp;
 
     /* Get the CPU Vendor */
-    BlArchCpuId(0, 0, CpuInfo);
-    Temp = CpuInfo[2];
-    CpuInfo[2] = CpuInfo[3];
-    CpuInfo[3] = Temp;
+    BlArchCpuId(0, 0, &CpuInfo);
+    Temp = CpuInfo.Ecx;
+    CpuInfo.Ecx = CpuInfo.Edx;
+    CpuInfo.Edx = Temp;
 
     /* Check against supported values */
-    if (!strncmp((PCHAR)&CpuInfo[1], "GenuineIntel", 12))
+    if (!strncmp((PCHAR)&CpuInfo.Ebx, "GenuineIntel", 12))
     {
         return CPU_INTEL;
     }
-    if (!strncmp((PCHAR)&CpuInfo[1], "AuthenticAMD", 12))
+    if (!strncmp((PCHAR)&CpuInfo.Ebx, "AuthenticAMD", 12))
     {
         return CPU_AMD;
     }
-    if (!strncmp((PCHAR)&CpuInfo[1], "CentaurHauls", 12))
+    if (!strncmp((PCHAR)&CpuInfo.Ebx, "CentaurHauls", 12))
     {
         return CPU_VIA;
     }
-    if (!strncmp((PCHAR)&CpuInfo[1], "CyrixInstead", 12))
+    if (!strncmp((PCHAR)&CpuInfo.Ebx, "CyrixInstead", 12))
     {
         return CPU_CYRIX;
     }
-    if (!strncmp((PCHAR)&CpuInfo[1], "GenuineTMx86", 12))
+    if (!strncmp((PCHAR)&CpuInfo.Ebx, "GenuineTMx86", 12))
     {
         return CPU_TRANSMETA;
     }
-    if (!strncmp((PCHAR)&CpuInfo[1], "RiseRiseRise", 12))
+    if (!strncmp((PCHAR)&CpuInfo.Ebx, "RiseRiseRise", 12))
     {
         return CPU_RISE;
     }
diff --git a/boot/environ/lib/mm/i386/mmx86.c b/boot/environ/lib/mm/i386/mmx86.c
index 38e52df1fd..b72a8983ae 100644
--- a/boot/environ/lib/mm/i386/mmx86.c
+++ b/boot/environ/lib/mm/i386/mmx86.c
@@ -1101,7 +1101,7 @@ MmArchInitialize (
 {
     NTSTATUS Status;
     ULONGLONG IncreaseUserVa, PerfCounter, CpuRandom;
-    INT CpuInfo[4];
+    CPU_INFO CpuInfo;
 
     /* For phase 2, just map deferred regions */
     if (Phase != 1)
@@ -1157,10 +1157,10 @@ MmArchInitialize (
             if (BlArchIsCpuIdFunctionSupported(1))
             {
                 /* Call it */
-                BlArchCpuId(1, 0, CpuInfo);
+                BlArchCpuId(1, 0, &CpuInfo);
 
                 /* Check if RDRAND is supported */
-                if (CpuInfo[2] & 0x40000000)
+                if (CpuInfo.Ecx & 0x40000000)
                 {
                     EfiPrintf(L"Your CPU can do RDRAND! Good for you!\r\n");
                     CpuRandom = 0;