Kernel/x86 - Fix PMem bitmap overflow

[tpg/acess2.git] / KernelLand / Kernel / arch / x86 / mm_phys.c

diff --git a/KernelLand/Kernel/arch/x86/mm_phys.c b/KernelLand/Kernel/arch/x86/mm_phys.c
index 37166a0..eb422c9 100644 (file)
--- a/KernelLand/Kernel/arch/x86/mm_phys.c
+++ b/KernelLand/Kernel/arch/x86/mm_phys.c
@@ -7,6 +7,7 @@
 #include <mm_virt.h>
 #include <pmemmap.h>
 #include <hal_proc.h>
+#include <semaphore.h>
 
 //#define USE_STACK    1
 #define TRACE_ALLOCS   0       // Print trace messages on AllocPhys/DerefPhys
@@ -41,11 +42,10 @@ void        **gaPageNodes = (void*)MM_PAGENODE_BASE;
 // === CODE ===
 void MM_Install(int NPMemRanges, tPMemMapEnt *PMemRanges)
 {
-       Uint    i;
        Uint64  maxAddr = 0;
        
        // --- Find largest address
-       for( i = 0; i < NPMemRanges; i ++ )
+       for( Uint i = 0; i < NPMemRanges; i ++ )
        {
                tPMemMapEnt     *ent = &PMemRanges[i];
                // If entry is RAM and is above `maxAddr`, change `maxAddr`
@@ -56,20 +56,33 @@ void MM_Install(int NPMemRanges, tPMemMapEnt *PMemRanges)
                        giTotalMemorySize += ent->Length >> 12;
                }
        }
+       LOG("giTotalMemorySize = %lli KiB", giTotalMemorySize*4);
+       LOG("maxAddr = 0x%X", maxAddr);
+       
+       // Clip to 32-bits
+       if( maxAddr > (1ULL << 32) ) {
+               maxAddr = (1ULL << 32);
+       }
        
        giPageCount = maxAddr >> 12;
        giLastPossibleFree = giPageCount - 1;
-       
        memsetd(gaPageBitmap, 0xFFFFFFFF, giPageCount/32);
        
        // Set up allocateable space
-       for( i = 0; i < NPMemRanges; i ++ )
+       for( Uint i = 0; i < NPMemRanges; i ++ )
        {
                tPMemMapEnt *ent = &PMemRanges[i];
                if( ent->Type == PMEMTYPE_FREE )
                {
                        Uint64  startpg = ent->Start / PAGE_SIZE;
                        Uint64  pgcount = ent->Length / PAGE_SIZE;
+                       // Ignore start addresses >32 bits
+                       if( startpg > (1 << 20) )
+                               continue ;
+                       // Clip lengths to 32-bit address space
+                       if( startpg + pgcount > (1<<20) )
+                               pgcount = (1<<20) - startpg;
+                       
                        while( startpg % 32 && pgcount ) {
                                gaPageBitmap[startpg/32] &= ~(1U << (startpg%32));
                                startpg ++;
@@ -86,13 +99,14 @@ void MM_Install(int NPMemRanges, tPMemMapEnt *PMemRanges)
                }
                else if( ent->Type == PMEMTYPE_USED )
                {
+                       // TODO: Clip?
                        giPhysAlloc += ent->Length / PAGE_SIZE;
                }
        }
 
        // Fill Superpage bitmap
        // - A set bit means that there are no free pages in this block of 32
-       for( i = 0; i < (giPageCount+31)/32; i ++ )
+       for( Uint i = 0; i < (giPageCount+31)/32; i ++ )
        {
                if( gaPageBitmap[i] + 1 == 0 ) {
                        gaSuperBitmap[i/32] |= (1 << i%32);
@@ -239,7 +253,7 @@ tPAddr MM_AllocPhys(void)
 
        // Release Spinlock
        Mutex_Release( &glPhysAlloc );
-       LEAVE('X', ret);
+       LEAVE('P', ret);
 
        #if TRACE_ALLOCS
        if( now() > 4000 ) {