* Added vm_debug_copy_page_memory() which copies memory from a potentially not

mapped page.
* debug_{mem,strl}cpy():
  - Added "team" parameter for specifying the address space the address are
    to be interpreted in.
  - When the standard memcpy() (with fault handler) fails, fall back to
    vm_debug_copy_page_memory().
* Added debug_is_debugged_team(): Predicate returning true, if the supplied
  team_id refers to the same team debug_get_debugged_thread() belongs to.
* Added DebuggedThreadSetter class for scope-based debug_set_debugged_thread().
  Made use of it in several debugger functions.
* print_demangled_call() (x86): Fixed unsafe memory access.

Allows KDL stack traces to work correctly again, even if the page daemon has
already unmapped the concerned pages.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@36230 a95241bf-73f2-0310-859d-f6bbb57e9c96

headers/private/kernel/debug.h

@@ -132,8 +132,10 @@ extern bool		debug_is_kernel_memory_accessible(addr_t address, size_t size,
 					uint32 protection);
 extern int		debug_call_with_fault_handler(jmp_buf jumpBuffer,
 					void (*function)(void*), void* parameter);
-extern status_t	debug_memcpy(void* to, const void* from, size_t size);
-extern ssize_t	debug_strlcpy(char* to, const char* from, size_t size);
+extern status_t	debug_memcpy(team_id teamID, void* to, const void* from,
+					size_t size);
+extern ssize_t	debug_strlcpy(team_id teamID, char* to, const char* from,
+					size_t size);
 
 extern char		kgetc(void);
 extern void		kputs(const char *string);
@@ -172,8 +174,9 @@ extern status_t	debug_get_next_demangled_argument(uint32* _cookie,
 
 extern struct thread* debug_set_debugged_thread(struct thread* thread);
 extern struct thread* debug_get_debugged_thread();
-extern struct arch_debug_registers* debug_get_debug_registers(int32 cpu);
+extern bool debug_is_debugged_team(team_id teamID);
 
+extern struct arch_debug_registers* debug_get_debug_registers(int32 cpu);
 
 extern status_t	_user_kernel_debugger(const char *message);
 extern void		_user_debug_output(const char *userString);
@@ -182,4 +185,27 @@ extern void		_user_debug_output(const char *userString);
 }
 #endif
 
+
+#ifdef __cplusplus
+
+struct DebuggedThreadSetter {
+	DebuggedThreadSetter(struct thread* thread)
+		:
+		fPreviousThread(debug_set_debugged_thread(thread))
+	{
+	}
+
+	~DebuggedThreadSetter()
+	{
+		debug_set_debugged_thread(fPreviousThread);
+	}
+
+private:
+	struct thread*	fPreviousThread;
+};
+
+
+#endif	// __cplusplus
+
+
 #endif	/* _KERNEL_DEBUG_H */

headers/private/kernel/vm/vm.h

@@ -140,6 +140,9 @@ status_t vm_memcpy_to_physical(addr_t to, const void* from, size_t length,
 			bool user);
 void vm_memcpy_physical_page(addr_t to, addr_t from);
 
+status_t vm_debug_copy_page_memory(team_id teamID, void* unsafeMemory,
+			void* buffer, size_t size, bool copyToUnsafe);
+
 // user syscalls
 area_id _user_create_area(const char *name, void **address, uint32 addressSpec,
 			size_t size, uint32 lock, uint32 protection);

src/system/kernel/arch/m68k/arch_debug.cpp

@@ -1,5 +1,5 @@
 /*
- * Copyright 2003-2009, Haiku Inc. All rights reserved.
+ * Copyright 2003-2010, Haiku Inc. All rights reserved.
  * Distributed under the terms of the MIT License.
  *
  * Authors:
@@ -66,8 +66,10 @@ static status_t
 get_next_frame(addr_t framePointer, addr_t *next, addr_t *ip)
 {
 	stack_frame frame;
-	if (debug_memcpy(&frame, (void*)framePointer, sizeof(frame)) != B_OK)
+	if (debug_memcpy(B_CURRENT_TEAM, &frame, (void*)framePointer, sizeof(frame))
+			!= B_OK) {
 		return B_BAD_ADDRESS;
+	}
 
 	*ip = frame.return_address;
 	*next = (addr_t)frame.previous;

src/system/kernel/arch/ppc/arch_debug.cpp

@@ -1,5 +1,5 @@
 /*
- * Copyright 2003-2009, Haiku Inc. All rights reserved.
+ * Copyright 2003-2010, Haiku Inc. All rights reserved.
  * Distributed under the terms of the MIT License.
  *
  * Authors:
@@ -65,8 +65,10 @@ static status_t
 get_next_frame(addr_t framePointer, addr_t *next, addr_t *ip)
 {
 	stack_frame frame;
-	if (debug_memcpy(&frame, (void*)framePointer, sizeof(frame)) != B_OK)
+	if (debug_memcpy(B_CURRENT_TEAM, &frame, (void*)framePointer, sizeof(frame))
+			!= B_OK) {
 		return B_BAD_ADDRESS;
+	}
 
 	*ip = frame.return_address;
 	*next = (addr_t)frame.previous;

src/system/kernel/arch/x86/arch_debug.cpp

@@ -1,5 +1,5 @@
 /*
- * Copyright 2009, Ingo Weinhold, [email protected].
+ * Copyright 2009-2010, Ingo Weinhold, [email protected].
  * Copyright 2002-2008, Axel Dörfler, [email protected].
  * Distributed under the terms of the MIT License.
  *
@@ -81,7 +81,7 @@ static status_t
 get_next_frame_debugger(addr_t ebp, addr_t *_next, addr_t *_eip)
 {
 	stack_frame frame;
-	if (debug_memcpy(&frame, (void*)ebp, sizeof(frame)) != B_OK)
+	if (debug_memcpy(B_CURRENT_TEAM, &frame, (void*)ebp, sizeof(frame)) != B_OK)
 		return B_BAD_ADDRESS;
 
 	*_eip = frame.return_address;
@@ -126,6 +126,21 @@ set_debug_argument_variable(int32 index, uint64 value)
 }
 
 
+template<typename Type>
+static Type
+read_function_argument_value(void* argument, bool& _valueKnown)
+{
+	Type value;
+	if (debug_memcpy(B_CURRENT_TEAM, &value, argument, sizeof(Type)) == B_OK) {
+		_valueKnown = true;
+		return value;
+	}
+
+	_valueKnown = false;
+	return 0;
+}
+
+
 static status_t
 print_demangled_call(const char* image, const char* symbol, addr_t args,
 	bool noObjectMethod, bool addDebugVariables)
@@ -151,10 +166,15 @@ print_demangled_call(const char* image, const char* symbol, addr_t args,
 		const char* lastName = strrchr(name, ':') - 1;
 		int namespaceLength = lastName - name;
 
-		kprintf("<%s> %.*s<\33[32m%p\33[0m>%s", image, namespaceLength, name,
-			*(uint32 **)arg, lastName);
+		uint32 argValue = 0;
+		if (debug_memcpy(B_CURRENT_TEAM, &argValue, arg, 4) == B_OK) {
+			kprintf("<%s> %.*s<\33[32m%#" B_PRIx32 "\33[0m>%s", image,
+				namespaceLength, name, argValue, lastName);
+		} else
+			kprintf("<%s> %.*s<???>%s", image, namespaceLength, name, lastName);
+
 		if (addDebugVariables)
-			set_debug_variable("_this", *(uint32 *)arg);
+			set_debug_variable("_this", argValue);
 		arg++;
 	} else
 		kprintf("<%s> %s", image, name);
@@ -172,78 +192,103 @@ print_demangled_call(const char* image, const char* symbol, addr_t args,
 		// retrieve value and type identifier
 
 		uint64 value;
+		bool valueKnown = false;
 
 		switch (type) {
 			case B_INT64_TYPE:
-				value = *(int64*)arg;
-				kprintf("int64: \33[34m%Ld\33[0m", value);
+				value = read_function_argument_value<int64>(arg, valueKnown);
+				if (valueKnown)
+					kprintf("int64: \33[34m%Ld\33[0m", value);
 				break;
 			case B_INT32_TYPE:
-				value = *(int32*)arg;
-				kprintf("int32: \33[34m%ld\33[0m", (int32)value);
+				value = read_function_argument_value<int32>(arg, valueKnown);
+				if (valueKnown)
+					kprintf("int32: \33[34m%ld\33[0m", (int32)value);
 				break;
 			case B_INT16_TYPE:
-				value = *(int16*)arg;
-				kprintf("int16: \33[34m%d\33[0m", (int16)value);
+				value = read_function_argument_value<int16>(arg, valueKnown);
+				if (valueKnown)
+					kprintf("int16: \33[34m%d\33[0m", (int16)value);
 				break;
 			case B_INT8_TYPE:
-				value = *(int8*)arg;
-				kprintf("int8: \33[34m%d\33[0m", (int8)value);
+				value = read_function_argument_value<int8>(arg, valueKnown);
+				if (valueKnown)
+					kprintf("int8: \33[34m%d\33[0m", (int8)value);
 				break;
 			case B_UINT64_TYPE:
-				value = *(uint64*)arg;
-				kprintf("uint64: \33[34m%#Lx\33[0m", value);
-				if (value < 0x100000)
-					kprintf(" (\33[34m%Lu\33[0m)", value);
+				value = read_function_argument_value<uint64>(arg, valueKnown);
+				if (valueKnown) {
+					kprintf("uint64: \33[34m%#Lx\33[0m", value);
+					if (value < 0x100000)
+						kprintf(" (\33[34m%Lu\33[0m)", value);
+				}
 				break;
 			case B_UINT32_TYPE:
-				value = *(uint32*)arg;
-				kprintf("uint32: \33[34m%#lx\33[0m", (uint32)value);
-				if (value < 0x100000)
-					kprintf(" (\33[34m%lu\33[0m)", (uint32)value);
+				value = read_function_argument_value<uint32>(arg, valueKnown);
+				if (valueKnown) {
+					kprintf("uint32: \33[34m%#lx\33[0m", (uint32)value);
+					if (value < 0x100000)
+						kprintf(" (\33[34m%lu\33[0m)", (uint32)value);
+				}
 				break;
 			case B_UINT16_TYPE:
-				value = *(uint16*)arg;
-				kprintf("uint16: \33[34m%#x\33[0m (\33[34m%u\33[0m)",
-					(uint16)value, (uint16)value);
+				value = read_function_argument_value<uint16>(arg, valueKnown);
+				if (valueKnown) {
+					kprintf("uint16: \33[34m%#x\33[0m (\33[34m%u\33[0m)",
+						(uint16)value, (uint16)value);
+				}
 				break;
 			case B_UINT8_TYPE:
-				value = *(uint8*)arg;
-				kprintf("uint8: \33[34m%#x\33[0m (\33[34m%u\33[0m)",
-					(uint8)value, (uint8)value);
+				value = read_function_argument_value<uint8>(arg, valueKnown);
+				if (valueKnown) {
+					kprintf("uint8: \33[34m%#x\33[0m (\33[34m%u\33[0m)",
+						(uint8)value, (uint8)value);
+				}
 				break;
 			case B_BOOL_TYPE:
-				value = *(uint8*)arg;
-				kprintf("\33[34m%s\33[0m", value ? "true" : "false");
+				value = read_function_argument_value<uint8>(arg, valueKnown);
+				if (valueKnown)
+					kprintf("\33[34m%s\33[0m", value ? "true" : "false");
 				break;
 			default:
 				if (buffer[0])
 					kprintf("%s: ", buffer);
 
 				if (length == 4) {
-					value = *(uint32*)arg;
-					if (value == 0
-						&& (type == B_POINTER_TYPE || type == B_REF_TYPE))
-						kprintf("NULL");
-					else
-						kprintf("\33[34m%#lx\33[0m", (uint32)value);
+					value = read_function_argument_value<uint32>(arg,
+						valueKnown);
+					if (valueKnown) {
+						if (value == 0
+							&& (type == B_POINTER_TYPE || type == B_REF_TYPE))
+							kprintf("NULL");
+						else
+							kprintf("\33[34m%#lx\33[0m", (uint32)value);
+					}
 					break;
 				}
 
-				if (length == 8)
-					value = *(uint64*)arg;
-				else
+
+				if (length == 8) {
+					value = read_function_argument_value<uint64>(arg,
+						valueKnown);
+				} else
 					value = (uint64)arg;
-				kprintf("\33[34m%#Lx\33[0m", value);
+
+				if (valueKnown)
+					kprintf("\33[34m%#Lx\33[0m", value);
 				break;
 		}
 
-		if (type == B_STRING_TYPE) {
+		if (!valueKnown)
+			kprintf("???");
+
+		if (valueKnown && type == B_STRING_TYPE) {
 			if (value == 0)
 				kprintf(" \33[31m\"<NULL>\"\33[0m");
-			else if (debug_strlcpy(buffer, (char*)value, kBufferSize) < B_OK)
+			else if (debug_strlcpy(B_CURRENT_TEAM, buffer, (char*)value,
+					kBufferSize) < B_OK) {
 				kprintf(" \33[31m\"<???>\"\33[0m");
-			else
+			} else
 				kprintf(" \33[36m\"%s\"\33[0m", buffer);
 		}
 
@@ -564,6 +609,8 @@ stack_trace(int argc, char **argv)
 			&thread, &ebp, &oldPageDirectory))
 		return 0;
 
+	DebuggedThreadSetter threadSetter(thread);
+
 	if (thread != NULL) {
 		kprintf("stack trace for thread %ld \"%s\"\n", thread->id,
 			thread->name);
@@ -736,6 +783,8 @@ show_call(int argc, char **argv)
 			&oldPageDirectory))
 		return 0;
 
+	DebuggedThreadSetter threadSetter(thread);
+
 	int32 callIndex = strtoul(argv[argc == 3 ? 2 : 1], NULL, 0);
 
 	if (thread != NULL)
@@ -816,6 +865,8 @@ dump_iframes(int argc, char **argv)
 	if (thread != NULL)
 		kprintf("iframes for thread %ld \"%s\"\n", thread->id, thread->name);
 
+	DebuggedThreadSetter threadSetter(thread);
+
 	struct iframe* frame = find_previous_iframe(thread, x86_read_ebp());
 	while (frame != NULL) {
 		print_iframe(frame);
@@ -889,12 +940,11 @@ cmd_in_context(int argc, char** argv)
 		}
 	}
 
-	struct thread* previousThread = debug_set_debugged_thread(thread);
-
 	// execute the command
-	evaluate_debug_command(commandLine);
-
-	debug_set_debugged_thread(previousThread);
+	{
+		DebuggedThreadSetter threadSetter(thread);
+		evaluate_debug_command(commandLine);
+	}
 
 	// reset the page directory
 	if (oldPageDirectory)
@@ -927,6 +977,8 @@ bool
 arch_debug_contains_call(struct thread *thread, const char *symbol,
 	addr_t start, addr_t end)
 {
+	DebuggedThreadSetter threadSetter(thread);
+
 	addr_t ebp;
 	if (thread == thread_get_current_thread())
 		ebp = x86_read_ebp();

src/system/kernel/debug/debug.cpp

@@ -1852,33 +1852,69 @@ debug_call_with_fault_handler(jmp_buf jumpBuffer, void (*function)(void*),
 
 /*!	Similar to user_memcpy(), but can only be invoked from within the kernel
 	debugger (and must not be used outside).
+	The supplied \a teamID specifies the address space in which to interpret
+	the addresses. It can be \c B_CURRENT_TEAM for debug_get_debugged_thread(),
+	or any valid team ID. If the addresses are both kernel addresses, the
+	argument is ignored and the current address space is used.
 */
 status_t
-debug_memcpy(void* to, const void* from, size_t size)
+debug_memcpy(team_id teamID, void* to, const void* from, size_t size)
 {
 	// don't allow address overflows
 	if ((addr_t)from + size < (addr_t)from || (addr_t)to + size < (addr_t)to)
 		return B_BAD_ADDRESS;
 
-	debug_memcpy_parameters parameters = {to, from, size};
+	// Try standard memcpy() with fault handler, if the addresses can be
+	// interpreted in the current address space.
+	if ((IS_KERNEL_ADDRESS(from) && IS_KERNEL_ADDRESS(to))
+			|| debug_is_debugged_team(teamID)) {
+		debug_memcpy_parameters parameters = {to, from, size};
 
-	if (debug_call_with_fault_handler(gCPU[sDebuggerOnCPU].fault_jump_buffer,
-			&debug_memcpy_trampoline, &parameters) != 0) {
-		return B_BAD_ADDRESS;
+		if (debug_call_with_fault_handler(gCPU[sDebuggerOnCPU].fault_jump_buffer,
+				&debug_memcpy_trampoline, &parameters) == 0) {
+			return B_OK;
+		}
 	}
+
+	// Try harder. The pages of the respective memory could be unmapped but
+	// still exist in a cache (the page daemon does that with inactive pages).
+	while (size > 0) {
+		uint8 buffer[32];
+		size_t toCopy = std::min(size, sizeof(buffer));
+
+		// restrict the size so we don't cross page boundaries
+		if (((addr_t)from + toCopy) % B_PAGE_SIZE < toCopy)
+			toCopy -= ((addr_t)from + toCopy) % B_PAGE_SIZE;
+		if (((addr_t)to + toCopy) % B_PAGE_SIZE < toCopy)
+			toCopy -= ((addr_t)to + toCopy) % B_PAGE_SIZE;
+
+		if (vm_debug_copy_page_memory(teamID, (void*)from, buffer, toCopy,
+				false) != B_OK
+			|| vm_debug_copy_page_memory(teamID, to, buffer, toCopy, true)
+				!= B_OK) {
+			return B_BAD_ADDRESS;
+		}
+
+		from = (const uint8*)from + toCopy;
+		to = (uint8*)to + toCopy;
+		size -= toCopy;
+	}
+
 	return B_OK;
 }
 
 
 /*!	Similar to user_strlcpy(), but can only be invoked from within the kernel
 	debugger (and must not be used outside).
+	The supplied \a teamID specifies the address space in which to interpret
+	the addresses. It can be \c B_CURRENT_TEAM for debug_get_debugged_thread(),
+	or any valid team ID. If the addresses are both kernel addresses, the
+	argument is ignored and the current address space is used.
 */
 ssize_t
-debug_strlcpy(char* to, const char* from, size_t size)
+debug_strlcpy(team_id teamID, char* to, const char* from, size_t size)
 {
-	if (size == 0)
-		return 0;
-	if (from == NULL || to == NULL)
+	if (from == NULL || (to == NULL && size > 0))
 		return B_BAD_ADDRESS;
 
 	// limit size to avoid address overflows
@@ -1887,18 +1923,80 @@ debug_strlcpy(char* to, const char* from, size_t size)
 		// NOTE: Since strlcpy() determines the length of \a from, the source
 		// address might still overflow.
 
-	debug_strlcpy_parameters parameters = {to, from, maxSize};
+	// Try standard strlcpy() with fault handler, if the addresses can be
+	// interpreted in the current address space.
+	if ((IS_KERNEL_ADDRESS(from) && IS_KERNEL_ADDRESS(to))
+			|| debug_is_debugged_team(teamID)) {
+		debug_strlcpy_parameters parameters = {to, from, maxSize};
 
-	if (debug_call_with_fault_handler(gCPU[sDebuggerOnCPU].fault_jump_buffer,
-			&debug_strlcpy_trampoline, &parameters) != 0) {
-		return B_BAD_ADDRESS;
+		if (debug_call_with_fault_handler(
+				gCPU[sDebuggerOnCPU].fault_jump_buffer,
+				&debug_strlcpy_trampoline, &parameters) == 0) {
+			// If we hit the address overflow boundary, fail.
+			if (parameters.result >= maxSize && maxSize < size)
+				return B_BAD_ADDRESS;
+
+			return parameters.result;
+		}
 	}
 
-	// If we hit the address overflow boundary, fail.
-	if (parameters.result >= maxSize && maxSize < size)
-		return B_BAD_ADDRESS;
+	// Try harder. The pages of the respective memory could be unmapped but
+	// still exist in a cache (the page daemon does that with inactive pages).
+	size_t totalLength = 0;
+	while (maxSize > 0) {
+		char buffer[32];
+		size_t toCopy = std::min(maxSize, sizeof(buffer));
 
-	return parameters.result;
+		// restrict the size so we don't cross page boundaries
+		if (((addr_t)from + toCopy) % B_PAGE_SIZE < toCopy)
+			toCopy -= ((addr_t)from + toCopy) % B_PAGE_SIZE;
+		if (((addr_t)to + toCopy) % B_PAGE_SIZE < toCopy)
+			toCopy -= ((addr_t)to + toCopy) % B_PAGE_SIZE;
+
+		// copy the next part of the string from the source
+		if (vm_debug_copy_page_memory(teamID, (void*)from, buffer, toCopy,
+				false) != B_OK) {
+			return B_BAD_ADDRESS;
+		}
+
+		// determine the length of the part and whether we've reached the end
+		// of the string
+		size_t length = strnlen(buffer, toCopy);
+		bool endOfString = length < toCopy;
+
+		from = (const char*)from + toCopy;
+		totalLength += length;
+		maxSize -= length;
+
+		if (endOfString) {
+			// only copy the actual string, including the terminating null
+			toCopy = length + 1;
+		}
+
+		if (size > 0) {
+			// We still have space left in the target buffer.
+			if (size <= length) {
+				// Not enough space for the complete part. Null-terminate it and
+				// copy what we can.
+				buffer[size - 1] = '\0';
+				totalLength += length - size;
+				toCopy = size;
+			}
+
+			if (vm_debug_copy_page_memory(teamID, to, buffer, toCopy, true)
+					!= B_OK) {
+				return B_BAD_ADDRESS;
+			}
+
+			to = (char*)to + toCopy;
+			size -= toCopy;
+		}
+
+		if (endOfString)
+			return totalLength;
+	}
+
+	return totalLength;
 }
 
 
@@ -2060,6 +2158,22 @@ debug_get_debugged_thread()
 }
 
 
+/*!	Returns whether the supplied team ID refers to the same team the currently
+	debugged thread (debug_get_debugged_thread()) belongs to.
+	Always returns \c true, if \c B_CURRENT_TEAM is given.
+*/
+bool
+debug_is_debugged_team(team_id teamID)
+{
+	if (teamID == B_CURRENT_TEAM)
+		return true;
+
+	struct thread* thread = debug_get_debugged_thread();
+	return thread != NULL && thread->team != NULL
+		&& thread->team->id == teamID;
+}
+
+
 //	#pragma mark -
 //	userland syscalls
 

src/system/kernel/debug/debug_parser.cpp

@@ -1,5 +1,5 @@
 /*
- * Copyright 2008-2009, Ingo Weinhold, ingo_weinhold@gmx.de
+ * Copyright 2008-2010, Ingo Weinhold, ingo_weinhold@gmx.de
  * Copyright 2006, Stephan Aßmus, superstippi@gmx.de
  * Distributed under the terms of the MIT License.
  */
@@ -723,7 +723,7 @@ ExpressionParser::_ParseExpression(bool expectAssignment)
 					break;
 			}
 
-			if (debug_memcpy(address, &buffer, size) != B_OK) {
+			if (debug_memcpy(B_CURRENT_TEAM, address, &buffer, size) != B_OK) {
 				snprintf(sTempBuffer, sizeof(sTempBuffer),
 					"failed to write to address %p", address);
 				parse_exception(sTempBuffer, position);
@@ -1062,7 +1062,7 @@ ExpressionParser::_ParseDereference(void** _address, uint32* _size)
 
 	// read bytes from address into a tempory buffer
 	uint64 buffer;
-	if (debug_memcpy(&buffer, address, size) != B_OK) {
+	if (debug_memcpy(B_CURRENT_TEAM, &buffer, address, size) != B_OK) {
 		snprintf(sTempBuffer, sizeof(sTempBuffer),
 			"failed to dereference address %p", address);
 		parse_exception(sTempBuffer, starPosition);

src/system/kernel/debug/gdb.cpp

@@ -296,9 +296,10 @@ gdb_parse_command(void)
 			// for gdb may be trying to access an stray pointer
 			// We copy the memory to a safe buffer using
 			// the bulletproof debug_memcpy().
-			if (debug_memcpy(sSafeMemory, (char*)address, len) < 0)
+			if (debug_memcpy(B_CURRENT_TEAM, sSafeMemory, (char*)address, len)
+					< 0) {
 				gdb_reply("E02");
-			else
+			} else
 				gdb_memreply(sSafeMemory, len);
 
 			break;

src/system/kernel/elf.cpp

@@ -1,5 +1,5 @@
 /*
- * Copyright 2009, Ingo Weinhold, ingo_weinhold@gmx.de.
+ * Copyright 2009-2010, Ingo Weinhold, ingo_weinhold@gmx.de.
  * Copyright 2002-2009, Axel Dörfler, axeld@pinc-software.de.
  * Distributed under the terms of the MIT License.
  *
@@ -1467,8 +1467,10 @@ public:
 		if (!IS_USER_ADDRESS(address))
 			return false;
 
-		if (debug_debugger_running())
-			return debug_strlcpy(buffer, address, bufferSize) >= 0;
+		if (debug_debugger_running()) {
+			return debug_strlcpy(B_CURRENT_TEAM, buffer, address, bufferSize)
+				>= 0;
+		}
 		return user_strlcpy(buffer, address, bufferSize) >= 0;
 	}
 
@@ -1491,7 +1493,7 @@ UserSymbolLookup::_Read(const T* address, T& data)
 		return false;
 
 	if (debug_debugger_running())
-		return debug_memcpy(&data, address, sizeof(T)) == B_OK;
+		return debug_memcpy(B_CURRENT_TEAM, &data, address, sizeof(T)) == B_OK;
 	return user_memcpy(&data, address, sizeof(T)) == B_OK;
 }
 

src/system/kernel/vm/vm.cpp

@@ -2640,9 +2640,11 @@ display_mem(int argc, char** argv)
 		// string mode
 		for (i = 0; true; i++) {
 			char c;
-			if (debug_memcpy(&c, (char*)copyAddress + i, 1) != B_OK
-				|| c == '\0')
+			if (debug_memcpy(B_CURRENT_TEAM, &c, (char*)copyAddress + i, 1)
+					!= B_OK
+				|| c == '\0') {
 				break;
+			}
 
 			if (c == '\n')
 				kprintf("\\n");
@@ -2671,8 +2673,8 @@ display_mem(int argc, char** argv)
 
 				for (j = 0; j < displayed; j++) {
 					char c;
-					if (debug_memcpy(&c, (char*)copyAddress + i * itemSize + j,
-							1) != B_OK) {
+					if (debug_memcpy(B_CURRENT_TEAM, &c,
+							(char*)copyAddress + i * itemSize + j, 1) != B_OK) {
 						displayed = j;
 						break;
 					}
@@ -2689,8 +2691,8 @@ display_mem(int argc, char** argv)
 				kprintf("  ");
 			}
 
-			if (debug_memcpy(&value, (uint8*)copyAddress + i * itemSize,
-					itemSize) != B_OK) {
+			if (debug_memcpy(B_CURRENT_TEAM, &value,
+					(uint8*)copyAddress + i * itemSize, itemSize) != B_OK) {
 				kprintf("read fault");
 				break;
 			}
@@ -4658,6 +4660,93 @@ vm_memcpy_physical_page(addr_t to, addr_t from)
 }
 
 
+/*!	Copies a range of memory directly from/to a page that might not be mapped
+	at the moment.
+
+	For \a unsafeMemory the current mapping (if any is ignored). The function
+	walks through the respective area's cache chain to find the physical page
+	and copies from/to it directly.
+	The memory range starting at \a unsafeMemory with a length of \a size bytes
+	must not cross a page boundary.
+
+	\param teamID The team ID identifying the address space \a unsafeMemory is
+		to be interpreted in. Ignored, if \a unsafeMemory is a kernel address
+		(the kernel address space is assumed in this case). If \c B_CURRENT_TEAM
+		is passed, the address space of the thread returned by
+		debug_get_debugged_thread() is used.
+	\param unsafeMemory The start of the unsafe memory range to be copied
+		from/to.
+	\param buffer A safely accessible kernel buffer to be copied from/to.
+	\param size The number of bytes to be copied.
+	\param copyToUnsafe If \c true, memory is copied from \a buffer to
+		\a unsafeMemory, the other way around otherwise.
+*/
+status_t
+vm_debug_copy_page_memory(team_id teamID, void* unsafeMemory, void* buffer,
+	size_t size, bool copyToUnsafe)
+{
+	if (size > B_PAGE_SIZE
+			|| ((addr_t)unsafeMemory + size) % B_PAGE_SIZE < size) {
+		return B_BAD_VALUE;
+	}
+
+	// get the address space for the debugged thread
+	VMAddressSpace* addressSpace;
+	if (IS_KERNEL_ADDRESS(unsafeMemory)) {
+		addressSpace = VMAddressSpace::Kernel();
+	} else if (teamID == B_CURRENT_TEAM) {
+		struct thread* thread = debug_get_debugged_thread();
+		if (thread == NULL || thread->team == NULL)
+			return B_BAD_ADDRESS;
+
+		addressSpace = thread->team->address_space;
+	} else
+		addressSpace = VMAddressSpace::DebugGet(teamID);
+
+	if (addressSpace == NULL)
+		return B_BAD_ADDRESS;
+
+	// get the area
+	VMArea* area = addressSpace->LookupArea((addr_t)unsafeMemory);
+	if (area == NULL)
+		return B_BAD_ADDRESS;
+
+	// search the page
+	off_t cacheOffset = (addr_t)unsafeMemory - area->Base()
+		+ area->cache_offset;
+	VMCache* cache = area->cache;
+	vm_page* page = NULL;
+	while (cache != NULL) {
+		page = cache->DebugLookupPage(cacheOffset);
+		if (page != NULL)
+			break;
+
+		// Page not found in this cache -- if it is paged out, we must not try
+		// to get it from lower caches.
+		if (cache->DebugHasPage(cacheOffset))
+			break;
+
+		cache = cache->source;
+	}
+
+	if (page == NULL)
+		return B_UNSUPPORTED;
+
+	// copy from/to physical memory
+	addr_t physicalAddress = page->physical_page_number * B_PAGE_SIZE
+		+ (addr_t)unsafeMemory % B_PAGE_SIZE;
+
+	if (copyToUnsafe) {
+		if (page->Cache() != area->cache)
+			return B_UNSUPPORTED;
+
+		return vm_memcpy_to_physical(physicalAddress, buffer, size, false);
+	}
+
+	return vm_memcpy_from_physical(buffer, physicalAddress, size, false);
+}
+
+
 //	#pragma mark - kernel public API