Kernel/x86_64 - Debugging iret->CPL3 crash

[tpg/acess2.git] / Kernel / arch / x86_64 / proc.c

diff --git a/Kernel/arch/x86_64/proc.c b/Kernel/arch/x86_64/proc.c
index e83c20a..8cc1933 100644 (file)
--- a/Kernel/arch/x86_64/proc.c
+++ b/Kernel/arch/x86_64/proc.c
@@ -467,7 +467,7 @@ int Proc_Clone(Uint Flags)
 {
        tThread *newThread, *cur = Proc_GetCurThread();
        Uint    rip;
-       Uint    _savedregs[16];
+       Uint    _savedregs[16+1];
        
        newThread = Threads_CloneTCB(NULL, Flags);
        if(!newThread)  return -1;
@@ -490,7 +490,12 @@ int Proc_Clone(Uint Flags)
                return -1;
        }
        
-       Log("New (Clone) %p, rsp = %p\n", rip, newThread->SavedState.RSP);
+       Log("New (Clone) %p, rsp = %p", rip, newThread->SavedState.RSP);
+       {
+               Uint cr3;
+               __asm__ __volatile__ ("mov %%cr3, %0" : "=r" (cr3));
+               Log(" CR3 = %x, PADDR(RSP) = %x", cr3, MM_GetPhysAddr(newThread->SavedState.RSP));
+       }
        
        // Set EIP as parent
        newThread->SavedState.RIP = rip;
@@ -603,7 +608,8 @@ void Proc_StartUser(Uint Entrypoint, Uint *Bases, int ArgC, char **ArgV, char **
        for( i = 0; EnvP[i]; i++ )      EnvP[i] += delta;
        
        // User Mode Segments
-       ss = 0x23;      cs = 0x1B;
+       // 0x2B = 64-bit
+       ss = 0x23;      cs = 0x2B;
        
        // Arguments
        *--stack = (Uint)EnvP;
@@ -611,26 +617,39 @@ void Proc_StartUser(Uint Entrypoint, Uint *Bases, int ArgC, char **ArgV, char **
        *--stack = (Uint)ArgC;
        while(*Bases)
                *--stack = *Bases++;
-       *--stack = 0;   // Return Address
        
        Proc_StartProcess(ss, (Uint)stack, 0x202, cs, Entrypoint);
 }
 
 void Proc_StartProcess(Uint16 SS, Uint Stack, Uint Flags, Uint16 CS, Uint IP)
 {
-       if( CS != 0x1B || SS != 0x23 ) {
+       if( !(CS == 0x1B || CS == 0x2B) || SS != 0x23 ) {
                Log_Error("Proc", "Proc_StartProcess: CS / SS are not valid (%x, %x)",
                        CS, SS);
                Threads_Exit(0, -1);
        }
-//     MAGIC_BREAK();  
-       __asm__ __volatile__ (
-               "mov %0, %%rsp;\n\t"    // Set stack pointer
-               "mov %1, %%r11;\n\t"    // Set stack pointer
-               "sysret;\n\t"
-               : : "r" (Stack), "c" (IP), "r" (Flags)
-               : "r11"
-               );
+       Log("Proc_StartProcess: (SS=%x, Stack=%p, Flags=%x, CS=%x, IP=%p)",
+               SS, Stack, Flags, CS, IP);
+       if(CS == 0x1B)
+       {
+               // 32-bit return
+               __asm__ __volatile__ (
+                       "mov %0, %%rsp;\n\t"    // Set stack pointer
+                       "mov %2, %%r11;\n\t"    // Set RFLAGS
+                       "sysret;\n\t"
+                       : : "r" (Stack), "c" (IP), "r" (Flags)
+                       );
+       }
+       else
+       {
+               // 64-bit return
+               __asm__ __volatile__ (
+                       "mov %0, %%rsp;\n\t"    // Set stack pointer
+                       "mov %2, %%r11;\n\t"    // Set RFLAGS
+                       "sysretq;\n\t"
+                       : : "r" (Stack), "c" (IP), "r" (Flags)
+                       );
+       }
        for(;;);
 }
 
@@ -769,9 +788,10 @@ void Proc_Scheduler(int CPU, Uint RSP, Uint RIP)
                "invlpg (%%rsp)\n\t"
                "invlpg 0x1000(%%rsp)\n\t"
                "invlpg -0x1000(%%rsp)\n\t"
+               "xor %%eax, %%eax\n\t"
                "jmp *%1" : :   // And return to where we saved state (Proc_Clone or Proc_Scheduler)
                "r"(thread->SavedState.RSP), "r"(thread->SavedState.RIP),
-               "r"(thread->MemState.CR3), "a" (0)
+               "r"(thread->MemState.CR3)
                );
        for(;;);        // Shouldn't reach here
 }