From c1b768104a3458d08e7c7240aaac82fc7e70e3df Mon Sep 17 00:00:00 2001
From: "John Hodge (sonata)" <tpg@mutabah.net>
Date: Mon, 26 Nov 2012 16:05:26 +0800
Subject: [PATCH] Kernel/x86_64 - Debugging GUI errors (and a wild goose chase)

---
 KernelLand/Kernel/arch/x86_64/desctab.asm     | 22 +++++--
 KernelLand/Kernel/arch/x86_64/errors.c        |  4 ++
 .../Kernel/arch/x86_64/include/mm_virt.h      |  2 +-
 KernelLand/Kernel/arch/x86_64/mm_virt.c       | 64 ++++++++++++++-----
 KernelLand/Kernel/arch/x86_64/proc.asm        |  2 +
 KernelLand/Kernel/arch/x86_64/proc.c          | 23 ++++++-
 KernelLand/Kernel/libc.c                      |  7 +-
 KernelLand/Kernel/syscalls.c                  | 13 ++--
 KernelLand/Kernel/threads.c                   |  2 +-
 KernelLand/Modules/Display/BochsGA/bochsvbe.c |  2 -
 10 files changed, 105 insertions(+), 36 deletions(-)

diff --git a/KernelLand/Kernel/arch/x86_64/desctab.asm b/KernelLand/Kernel/arch/x86_64/desctab.asm
index 22b41be0..e8331735 100644
--- a/KernelLand/Kernel/arch/x86_64/desctab.asm
+++ b/KernelLand/Kernel/arch/x86_64/desctab.asm
@@ -276,17 +276,23 @@ DEFIRQ	i
 %assign i i+1
 %endrep
 
+[extern Proc_int_SetIRQIP]
+
 [global IrqCommon]
 IrqCommon:
 	PUSH_GPR
 	push gs
 	push fs
-
+	
+	mov rdi, [rsp+(16+2+2)*8]	; 2SReg + GPRs + Int/Errcode = RIP
+	call Proc_int_SetIRQIP
+	push rax
+	
 ;	mov rdi, csIRQ_Fired
 ;	mov rsi, [rsp+(16+2)*8]
 ;	call Log
 	
-	mov ebx, [rsp+(16+2)*8]	; Get interrupt number (16 GPRS + 2 SRs)
+	mov ebx, [rsp+(1+2+16)*8]	; Get interrupt number (16 GPRS + 2 SRs)
 	shl ebx, 2	; *4
 	mov rax, gaIRQ_Handlers
 	lea rbx, [rax+rbx*8]
@@ -300,7 +306,7 @@ IrqCommon:
 	test rax, rax	; Check if it exists
 	jz .skip.%[i]
 	; Set RDI to IRQ number
-	mov rdi, [rsp+(16+2+1)*8]	; Get IRQ number
+	mov rdi, [rsp+(16+2+1+1)*8]	; Get IRQ number
 	mov rsi, [rbx-gaIRQ_Handlers+gaIRQ_DataPtrs]
 	call rax	; Call
 .skip.%[i]:
@@ -311,12 +317,15 @@ IrqCommon:
 	
 	; ACK
 	mov al, 0x20
-	mov rdi, [rsp+(16+2)*8]	; Get IRQ number
+	mov rdi, [rsp+(16+2+1)*8]	; Get IRQ number
 	cmp rdi, 8
 	jb .skipAckSecondary
 	out 0xA0, al
 .skipAckSecondary:
 	out 0x20, al
+
+	pop rdi
+	call Proc_int_SetIRQIP
 	
 	pop fs
 	pop gs
@@ -398,7 +407,10 @@ SyscallStub:
 	mov [rsp+0x28], r10	; Arg4
 	mov [rsp+0x30], r8	; Arg5
 	mov [rsp+0x38], r9	; Arg6
-	
+
+	mov rdi, rcx	
+	call Proc_int_SetIRQIP
+
 	mov rdi, rsp
 	sub rsp, 8
 	call SyscallHandler
diff --git a/KernelLand/Kernel/arch/x86_64/errors.c b/KernelLand/Kernel/arch/x86_64/errors.c
index e7812c3e..fda31139 100644
--- a/KernelLand/Kernel/arch/x86_64/errors.c
+++ b/KernelLand/Kernel/arch/x86_64/errors.c
@@ -13,6 +13,7 @@
 extern int	MM_PageFault(tVAddr Addr, Uint ErrorCode, tRegs *Regs);
 extern void	Error_Backtrace(Uint IP, Uint BP);
 extern void	Proc_EnableSSE(void);
+extern void	Threads_Dump(void);
 extern void	Proc_RestoreSSE(Uint32 Data);
 
 // === PROTOTYPES ===
@@ -98,6 +99,9 @@ void Error_Handler(tRegs *Regs)
 			*(Uint8*)(Regs->RIP+2), *(Uint8*)(Regs->RIP+3)
 			);
 		break;
+	case 2: // NMI
+		Threads_Dump();
+		break;
 	}
 	
 	__asm__ __volatile__ ("cli");
diff --git a/KernelLand/Kernel/arch/x86_64/include/mm_virt.h b/KernelLand/Kernel/arch/x86_64/include/mm_virt.h
index 6cf25f02..120afb3f 100644
--- a/KernelLand/Kernel/arch/x86_64/include/mm_virt.h
+++ b/KernelLand/Kernel/arch/x86_64/include/mm_virt.h
@@ -84,7 +84,7 @@
 // === FUNCTIONS ===
 void	MM_FinishVirtualInit(void);
 tVAddr	MM_NewKStack(void);
-tVAddr	MM_Clone(void);
+tVAddr	MM_Clone(int bCopyUser);
 tVAddr	MM_NewWorkerStack(void *StackData, size_t StackSize);
 
 #endif
diff --git a/KernelLand/Kernel/arch/x86_64/mm_virt.c b/KernelLand/Kernel/arch/x86_64/mm_virt.c
index e1e59c08..de7ae521 100644
--- a/KernelLand/Kernel/arch/x86_64/mm_virt.c
+++ b/KernelLand/Kernel/arch/x86_64/mm_virt.c
@@ -722,43 +722,73 @@ int MM_IsValidBuffer(tVAddr Addr, size_t Size)
 
 	Size += Addr & (PAGE_SIZE-1);
 	Addr &= ~(PAGE_SIZE-1);
-	Addr &= ((1UL << 48)-1);	// Clap to address space
+	// NC addr
+	if( ((Addr >> 47) & 1) != ((Addr>>48) == 0xFFFF))
+		return 0;
+	Addr &= ((1UL << 48)-1);	// Clamp to address space
 
 	pml4 = Addr >> 39;
 	pdp = Addr >> 30;
 	dir = Addr >> 21;
 	tab = Addr >> 12;
 
-	if( !(PAGEMAPLVL4(pml4) & 1) )	return 0;
-	if( !(PAGEDIRPTR(pdp) & 1) )	return 0;
-	if( !(PAGEDIR(dir) & 1) )	return 0;
-	if( !(PAGETABLE(tab) & 1) )	return 0;
+	if( !(PAGEMAPLVL4(pml4) & 1) ) {
+		Log_Debug("MMVirt", "PML4E %i NP", pml4);
+		return 0;
+	}
+	if( !(PAGEDIRPTR(pdp) & 1) ) {
+		Log_Debug("MMVirt", "PDPE %i NP", pdp);
+		return 0;
+	}
+	if( !(PAGEDIR(dir) & 1) ) {
+		Log_Debug("MMVirt", "PDE %i NP", dir);
+		return 0;
+	}
+	if( !(PAGETABLE(tab) & 1) ) {
+		Log_Debug("MMVirt", "PTE %i NP", tab);
+		return 0;
+	}
 	
 	bIsUser = !!(PAGETABLE(tab) & PF_USER);
 
 	while( Size >= PAGE_SIZE )
 	{
+		tab ++;
+		Size -= PAGE_SIZE;
+		
 		if( (tab & 511) == 0 )
 		{
 			dir ++;
-			if( ((dir >> 9) & 511) == 0 )
+			if( (dir & 511) == 0 )
 			{
 				pdp ++;
-				if( ((pdp >> 18) & 511) == 0 )
+				if( (pdp & 511) == 0 )
 				{
 					pml4 ++;
-					if( !(PAGEMAPLVL4(pml4) & 1) )	return 0;
+					if( !(PAGEMAPLVL4(pml4) & 1) ) {
+						Log_Debug("MMVirt", "IsValidBuffer - PML4E %x NP, Size=%x", pml4, Size);
+						return 0;
+					}
+				}
+				if( !(PAGEDIRPTR(pdp) & 1) ) {
+					Log_Debug("MMVirt", "IsValidBuffer - PDPE %x NP", pdp);
+					return 0;
 				}
-				if( !(PAGEDIRPTR(pdp) & 1) )	return 0;
 			}
-			if( !(PAGEDIR(dir) & 1) )	return 0;
+			if( !(PAGEDIR(dir) & 1) ) {
+				Log_Debug("MMVirt", "IsValidBuffer - PDE %x NP", dir);
+				return 0;
+			}
 		}
 		
-		if( !(PAGETABLE(tab) & 1) )   return 0;
-		if( bIsUser && !(PAGETABLE(tab) & PF_USER) )	return 0;
-
-		tab ++;
-		Size -= PAGE_SIZE;
+		if( !(PAGETABLE(tab) & 1) ) {
+			Log_Debug("MMVirt", "IsValidBuffer - PTE %x NP", tab);
+			return 0;
+		}
+		if( bIsUser && !(PAGETABLE(tab) & PF_USER) ) {
+			Log_Debug("MMVirt", "IsValidBuffer - PTE %x Not user", tab);
+			return 0;
+		}
 	}
 	return 1;
 }
@@ -894,7 +924,7 @@ void MM_FreeTemp(void *Ptr)
 
 
 // --- Address Space Clone --
-tPAddr MM_Clone(void)
+tPAddr MM_Clone(int bNoUserCopy)
 {
 	tPAddr	ret;
 	 int	i;
@@ -910,7 +940,7 @@ tPAddr MM_Clone(void)
 	INVLPG_ALL();
 	
 	// #3 Set Copy-On-Write to all user pages
-	if( Threads_GetPID() != 0 )
+	if( Threads_GetPID() != 0 && !bNoUserCopy )
 	{
 		for( i = 0; i < 256; i ++)
 		{
diff --git a/KernelLand/Kernel/arch/x86_64/proc.asm b/KernelLand/Kernel/arch/x86_64/proc.asm
index f44d65b0..f3b3a28a 100644
--- a/KernelLand/Kernel/arch/x86_64/proc.asm
+++ b/KernelLand/Kernel/arch/x86_64/proc.asm
@@ -39,6 +39,8 @@ Proc_CloneInt:
 	PUSH_GPR
 	; Save RSP
 	mov [rdi], rsp
+	; Call MM_Clone (with bNoUserCopy flag)
+	mov rdi, rdx
 	call MM_Clone
 	; Save CR3
 	mov rsi, [rsp+0x30]	; Saved version of RSI
diff --git a/KernelLand/Kernel/arch/x86_64/proc.c b/KernelLand/Kernel/arch/x86_64/proc.c
index 884babb3..46e2b21c 100644
--- a/KernelLand/Kernel/arch/x86_64/proc.c
+++ b/KernelLand/Kernel/arch/x86_64/proc.c
@@ -37,7 +37,7 @@ extern void	APStartup(void);	// 16-bit AP startup code
 
 extern Uint	GetRIP(void);	// start.asm
 extern Uint	SaveState(Uint *RSP, Uint *Regs);
-extern Uint	Proc_CloneInt(Uint *RSP, Uint *CR3);
+extern Uint	Proc_CloneInt(Uint *RSP, Uint *CR3, int bCopyUserVM);
 extern void	NewTaskHeader(void);	// Actually takes cdecl args
 extern void	Proc_InitialiseSSE(void);
 extern void	Proc_SaveSSE(Uint DestPtr);
@@ -75,6 +75,7 @@ void	Proc_StartProcess(Uint16 SS, Uint Stack, Uint Flags, Uint16 CS, Uint IP) NO
 //void	Proc_DumpThreadCPUState(tThread *Thread);
 //void	Proc_Reschedule(void);
 void	Proc_Scheduler(int CPU, Uint RSP, Uint RIP);
+Uint	Proc_int_SetIRQIP(Uint RIP);
 
 // === GLOBALS ===
 //!\brief Used by desctab.asm in SyscallStub
@@ -507,7 +508,7 @@ tTID Proc_Clone(Uint Flags)
 	if(!newThread)	return -1;
 	
 	// Save core machine state
-	rip = Proc_CloneInt(&newThread->SavedState.RSP, &newThread->Process->MemState.CR3);
+	rip = Proc_CloneInt(&newThread->SavedState.RSP, &newThread->Process->MemState.CR3, !!(Flags & CLONE_NOUSER));
 	if(rip == 0)	return 0;	// Child
 	newThread->KernelStack = cur->KernelStack;
 	newThread->SavedState.RIP = rip;
@@ -725,7 +726,14 @@ void Proc_CallFaultHandler(tThread *Thread)
 
 void Proc_DumpThreadCPUState(tThread *Thread)
 {
-	Log("  At %04x:%016llx", Thread->SavedState.UserCS, Thread->SavedState.UserRIP);
+	if( Thread->CurCPU == GetCPUNum() ) {
+		// TODO: Backtrace to IRQ
+		Log("  IRQ %016llx", Thread->SavedState.UserRIP);
+	}
+	else {
+		Log("  At %016llx, SP=%016llx", Thread->SavedState.RIP, Thread->SavedState.RSP);
+		Log("  User %04x:%016llx", Thread->SavedState.UserCS, Thread->SavedState.UserRIP);
+	}
 }
 
 void Proc_Reschedule(void)
@@ -825,5 +833,14 @@ void Proc_Scheduler(int CPU, Uint RSP, Uint RIP)
 #endif
 }
 
+Uint Proc_int_SetIRQIP(Uint RIP)
+{
+	 int	cpu = GetCPUNum();
+	tThread	*thread = gaCPUs[cpu].Current;
+	Uint	rv = thread->SavedState.UserRIP;
+	thread->SavedState.UserRIP = RIP;
+	return rv;
+}
+
 // === EXPORTS ===
 EXPORT(Proc_SpawnWorker);
diff --git a/KernelLand/Kernel/libc.c b/KernelLand/Kernel/libc.c
index 1b6f3716..c6df2cd6 100644
--- a/KernelLand/Kernel/libc.c
+++ b/KernelLand/Kernel/libc.c
@@ -226,7 +226,9 @@ int vsnprintf(char *__s, size_t __maxlen, const char *__format, va_list args)
 		if(c == 'p') {
 			Uint	ptr = va_arg(args, Uint);
 			PUTCH('*');	PUTCH('0');	PUTCH('x');
-			for( len = BITS/4; len --; )
+			for( len = BITS/4; len -- && ((ptr>>(len*4))&15) == 0; )
+				;
+			for( len ++; len --; )
 				PUTCH( cUCDIGITS[ (ptr>>(len*4))&15 ] );
 			continue ;
 		}
@@ -738,7 +740,8 @@ void *memmove(void *__dest, const void *__src, size_t len)
 	
 }
 
-// NOTE: Strictly not libc, but lib.c is used by userland code too
+// NOTE: Strictly not libc, but lib.c is used by userland code too and hence these two
+// can't be in it.
 /**
  * \name Memory Validation
  * \{
diff --git a/KernelLand/Kernel/syscalls.c b/KernelLand/Kernel/syscalls.c
index 5a1d5967..82389bbb 100644
--- a/KernelLand/Kernel/syscalls.c
+++ b/KernelLand/Kernel/syscalls.c
@@ -13,13 +13,13 @@
 #include <events.h>
 
 #define CHECK_NUM_NULLOK(v,size)	\
-	if((v)&&!Syscall_Valid((size),(v))){ret=-1;err=-EINVAL;break;}
+	if((v)&&!Syscall_Valid((size),(v))){LOG("CHECK_NUM_NULLOK: %p(%x) FAIL",v,size);ret=-1;err=-EINVAL;break;}
 #define CHECK_STR_NULLOK(v)	\
-	if((v)&&!Syscall_ValidString((v))){ret=-1;err=-EINVAL;break;}
+	if((v)&&!Syscall_ValidString((v))){LOG("CHECK_STR_NULLOK: %p FAIL",v);ret=-1;err=-EINVAL;break;}
 #define CHECK_NUM_NONULL(v,size)	\
-	if(!(v)||!Syscall_Valid((size),(v))){ret=-1;err=-EINVAL;break;}
+	if(!(v)||!Syscall_Valid((size),(v))){LOG("CHECK_NUM_NONULL: %p(%x) FAIL",v,size);ret=-1;err=-EINVAL;break;}
 #define CHECK_STR_NONULL(v)	\
-	if(!(v)||!Syscall_ValidString((v))){ret=-1;err=-EINVAL;break;}
+	if(!(v)||!Syscall_ValidString((v))){LOG("CHECK_STR_NONULL: %p FAIL",v);ret=-1;err=-EINVAL;break;}
 #define CHECK_STR_ARRAY(arr)	do {\
 	 int	i;\
 	char	**tmp = (char**)arr; \
@@ -400,7 +400,10 @@ int Syscall_ValidString(const char *Addr)
  */
 int Syscall_Valid(int Size, const void *Addr)
 {
-	if(!MM_IsUser( (tVAddr)Addr ))	return 0;
+	if(!MM_IsUser( (tVAddr)Addr )) {
+		Log_Debug("Syscalls", "Syscall_Valid - %p not user", Addr);
+		return 0;
+	}
 	
 	return CheckMem( Addr, Size );
 }
diff --git a/KernelLand/Kernel/threads.c b/KernelLand/Kernel/threads.c
index 17cccca1..a21db4af 100644
--- a/KernelLand/Kernel/threads.c
+++ b/KernelLand/Kernel/threads.c
@@ -1079,7 +1079,7 @@ void Threads_int_DumpThread(tThread *thread)
 	default:	break;
 	}
 	Log("  Priority %i, Quantum %i", thread->Priority, thread->Quantum);
-	Log("  KStack 0x%x", thread->KernelStack);
+	Log("  KStack %p", thread->KernelStack);
 	if( thread->bInstrTrace )
 		Log("  Tracing Enabled");
 	Proc_DumpThreadCPUState(thread);
diff --git a/KernelLand/Modules/Display/BochsGA/bochsvbe.c b/KernelLand/Modules/Display/BochsGA/bochsvbe.c
index 70f0c915..84473df7 100644
--- a/KernelLand/Modules/Display/BochsGA/bochsvbe.c
+++ b/KernelLand/Modules/Display/BochsGA/bochsvbe.c
@@ -47,8 +47,6 @@ enum {
 	VBE_DISPI_INDEX_Y_OFFSET
 };
 
-extern void MM_DumpTables(tVAddr Start, tVAddr End);
-
 // === PROTOTYPES ===
 // Driver
  int	BGA_Install(char **Arguments);
-- 
2.20.1