Fixes to error handling and User text mappings

[tpg/acess2.git] / Kernel / arch / x86 / mm_virt.c

diff --git a/Kernel/arch/x86/mm_virt.c b/Kernel/arch/x86/mm_virt.c
index 6976c65..f3cd7bb 100644 (file)
--- a/Kernel/arch/x86/mm_virt.c
+++ b/Kernel/arch/x86/mm_virt.c
@@ -9,7 +9,7 @@
  * 0xFE - Unused
  * 0xFF - System Calls / Kernel's User Code
  */
-#define DEBUG  1
+#define DEBUG  0
 #define SANITY 1
 #include <acess.h>
 #include <mm_phys.h>
@@ -66,6 +66,7 @@ typedef Uint32        tTabEnt;
 #endif
 
 // === IMPORTS ===
+extern void    _UsertextEnd, _UsertextBase;
 extern Uint32  gaInitPageDir[1024];
 extern Uint32  gaInitPageTable[1024];
 extern void    Threads_SegFault(tVAddr Addr);
@@ -153,6 +154,12 @@ void MM_InstallVirtual()
                memset( &gaPageTable[i*1024], 0, 0x1000 );
        }
        #endif
+       
+       // Unset kernel on the User Text pages
+       for( i = ((tVAddr)&_UsertextEnd-(tVAddr)&_UsertextBase+0xFFF)/4096; i--; ) {
+               Log("MM_SetFlags( 0x%08x, 0, MM_PFLAG_KERNEL)", (tVAddr)&_UsertextBase + i*4096);
+               MM_SetFlags( (tVAddr)&_UsertextBase + i*4096, 0, MM_PFLAG_KERNEL );
+       }
 }
 
 /**
@@ -208,12 +215,14 @@ void MM_PageFault(tVAddr Addr, Uint ErrorCode, tRegs *Regs)
                        (ErrorCode&1?"bad/locked":"non-present"),
                        (ErrorCode&16?" (Instruction Fetch)":"")
                        );
-               Warning("User Pagefault: Instruction at %p accessed %p", Regs->eip, Addr);
+               Warning("User Pagefault: Instruction at %04x:%08x accessed %p", Regs->cs, Regs->eip, Addr);
                __asm__ __volatile__ ("sti");   // Restart IRQs
                Threads_SegFault(Addr);
                return ;
        }
        
+       Debug_KernelPanic();
+       
        // -- Check Error Code --
        if(ErrorCode & 8)
                Warning("Reserved Bits Trashed!");
@@ -779,15 +788,25 @@ void MM_SetFlags(tVAddr VAddr, Uint Flags, Uint Mask)
        // Read-Only
        if( Mask & MM_PFLAG_RO )
        {
-               if( Flags & MM_PFLAG_RO )       *ent &= ~PF_WRITE;
-               else    *ent |= PF_WRITE;
+               if( Flags & MM_PFLAG_RO ) {
+                       *ent &= ~PF_WRITE;
+               }
+               else {
+                       gaPageDir[VAddr >> 22] |= PF_WRITE;
+                       *ent |= PF_WRITE;
+               }
        }
        
        // Kernel
        if( Mask & MM_PFLAG_KERNEL )
        {
-               if( Flags & MM_PFLAG_KERNEL )   *ent &= ~PF_USER;
-               else    *ent |= PF_USER;
+               if( Flags & MM_PFLAG_KERNEL ) {
+                       *ent &= ~PF_USER;
+               }
+               else {
+                       gaPageDir[VAddr >> 22] |= PF_USER;
+                       *ent |= PF_USER;
+               }
        }
        
        // Copy-On-Write
@@ -802,6 +821,9 @@ void MM_SetFlags(tVAddr VAddr, Uint Flags, Uint Mask)
                        *ent |= PF_WRITE;
                }
        }
+       
+       //Log("MM_SetFlags: *ent = 0x%08x, gaPageDir[%i] = 0x%08x",
+       //      *ent, VAddr >> 22, gaPageDir[VAddr >> 22]);
 }
 
 /**
@@ -1011,7 +1033,7 @@ void MM_UnmapHWPages(tVAddr VAddr, Uint Number)
        
        for( j = 0; j < Number; j++ )
        {
-               MM_DerefPhys( gaPageTable[ (HW_MAP_ADDR >> 12) + i + j ] );
+               MM_DerefPhys( gaPageTable[ (HW_MAP_ADDR >> 12) + i + j ] & ~0xFFF );
                gaPageTable[ (HW_MAP_ADDR >> 12) + i + j ] = 0;
        }