vfs: check userland buffers before reading them.

[haiku.git] / src / kits / debug / debug_support.cpp

/*
 * Copyright 2005-2009, Ingo Weinhold, ingo_weinhold@gmx.de.
 * Copyright 2010-2013, Rene Gollent, rene@gollent.com.
 * Distributed under the terms of the MIT License.
 */

#include <new>

#include <string.h>

#include <AutoDeleter.h>
#include <debug_support.h>

#include "arch_debug_support.h"
#include "Image.h"
#include "SymbolLookup.h"


using std::nothrow;


struct debug_symbol_lookup_context {
        SymbolLookup*   lookup;
};

struct debug_symbol_iterator : BPrivate::Debug::SymbolIterator {
        bool    ownsImage;

        debug_symbol_iterator()
                :
                ownsImage(false)
        {
        }

        ~debug_symbol_iterator()
        {
                if (ownsImage)
                        delete image;
        }
};


// init_debug_context
status_t
init_debug_context(debug_context *context, team_id team, port_id nubPort)
{
        if (!context || team < 0 || nubPort < 0)
                return B_BAD_VALUE;

        context->team = team;
        context->nub_port = nubPort;

        // create the reply port
        context->reply_port = create_port(1, "debug reply port");
        if (context->reply_port < 0)
                return context->reply_port;

        return B_OK;
}

// destroy_debug_context
void
destroy_debug_context(debug_context *context)
{
        if (context) {
                if (context->reply_port >= 0)
                        delete_port(context->reply_port);

                context->team = -1;
                context->nub_port = -1;
                context->reply_port = -1;
        }
}

// send_debug_message
status_t
send_debug_message(debug_context *context, int32 messageCode,
        const void *message, int32 messageSize, void *reply, int32 replySize)
{
        if (!context)
                return B_BAD_VALUE;

        // send message
        while (true) {
                status_t result = write_port(context->nub_port, messageCode, message,
                        messageSize);
                if (result == B_OK)
                        break;
                if (result != B_INTERRUPTED)
                        return result;
        }

        if (!reply)
                return B_OK;

        // read reply
        while (true) {
                int32 code;
                ssize_t bytesRead = read_port(context->reply_port, &code, reply,
                        replySize);
                if (bytesRead > 0)
                        return B_OK;
                if (bytesRead != B_INTERRUPTED)
                        return bytesRead;
        }
}

// debug_read_memory_partial
ssize_t
debug_read_memory_partial(debug_context *context, const void *address,
        void *buffer, size_t size)
{
        if (!context)
                return B_BAD_VALUE;

        if (size == 0)
                return 0;
        if (size > B_MAX_READ_WRITE_MEMORY_SIZE)
                size = B_MAX_READ_WRITE_MEMORY_SIZE;

        // prepare the message
        debug_nub_read_memory message;
        message.reply_port = context->reply_port;
        message.address = (void*)address;
        message.size = size;

        // send the message
        debug_nub_read_memory_reply reply;
        status_t error = send_debug_message(context, B_DEBUG_MESSAGE_READ_MEMORY,
                &message, sizeof(message), &reply, sizeof(reply));

        if (error != B_OK)
                return error;
        if (reply.error != B_OK)
                return reply.error;

        // copy the read data
        memcpy(buffer, reply.data, reply.size);
        return reply.size;
}

// debug_read_memory
ssize_t
debug_read_memory(debug_context *context, const void *_address, void *_buffer,
        size_t size)
{
        const char *address = (const char *)_address;
        char *buffer = (char*)_buffer;

        // check parameters
        if (!context || !address || !buffer)
                return B_BAD_VALUE;
        if (size == 0)
                return 0;

        // read as long as we can read data
        ssize_t sumRead = 0;
        while (size > 0) {
                ssize_t bytesRead = debug_read_memory_partial(context, address, buffer,
                        size);
                if (bytesRead < 0) {
                        if (sumRead > 0)
                                return sumRead;
                        return bytesRead;
                }

                address += bytesRead;
                buffer += bytesRead;
                sumRead += bytesRead;
                size -= bytesRead;
        }

        return sumRead;
}

// debug_read_string
ssize_t
debug_read_string(debug_context *context, const void *_address, char *buffer,
        size_t size)
{
        const char *address = (const char *)_address;

        // check parameters
        if (!context || !address || !buffer || size == 0)
                return B_BAD_VALUE;

        // read as long as we can read data
        ssize_t sumRead = 0;
        while (size > 0) {
                ssize_t bytesRead = debug_read_memory_partial(context, address, buffer,
                        size);
                if (bytesRead < 0) {
                        // always null-terminate what we have (even, if it is an empty
                        // string) and be done
                        *buffer = '\0';
                        return (sumRead > 0 ? sumRead : bytesRead);
                }

                int chunkSize = strnlen(buffer, bytesRead);
                if (chunkSize < bytesRead) {
                        // we found a terminating null
                        sumRead += chunkSize;
                        return sumRead;
                }

                address += bytesRead;
                buffer += bytesRead;
                sumRead += bytesRead;
                size -= bytesRead;
        }

        // We filled the complete buffer without encountering a terminating null
        // replace the last char. But nevertheless return the full size to indicate
        // that the buffer was too small.
        buffer[-1] = '\0';

        return sumRead;
}

// debug_write_memory_partial
ssize_t
debug_write_memory_partial(debug_context *context, const void *address,
        void *buffer, size_t size)
{
        if (!context)
                return B_BAD_VALUE;

        if (size == 0)
                return 0;
        if (size > B_MAX_READ_WRITE_MEMORY_SIZE)
                size = B_MAX_READ_WRITE_MEMORY_SIZE;

        // prepare the message
        debug_nub_write_memory message;
        message.reply_port = context->reply_port;
        message.address = (void*)address;
        message.size = size;
        memcpy(message.data, buffer, size);

        // send the message
        debug_nub_write_memory_reply reply;
        status_t error = send_debug_message(context, B_DEBUG_MESSAGE_WRITE_MEMORY,
                &message, sizeof(message), &reply, sizeof(reply));

        if (error != B_OK)
                return error;
        if (reply.error != B_OK)
                return reply.error;

        return reply.size;
}

// debug_write_memory
ssize_t
debug_write_memory(debug_context *context, const void *_address, void *_buffer,
        size_t size)
{
        const char *address = (const char *)_address;
        char *buffer = (char*)_buffer;

        // check parameters
        if (!context || !address || !buffer)
                return B_BAD_VALUE;
        if (size == 0)
                return 0;

        ssize_t sumWritten = 0;
        while (size > 0) {
                ssize_t bytesWritten = debug_write_memory_partial(context, address, buffer,
                        size);
                if (bytesWritten < 0) {
                        if (sumWritten > 0)
                                return sumWritten;
                        return bytesWritten;
                }

                address += bytesWritten;
                buffer += bytesWritten;
                sumWritten += bytesWritten;
                size -= bytesWritten;
        }

        return sumWritten;
}

// debug_get_cpu_state
status_t
debug_get_cpu_state(debug_context *context, thread_id thread,
        debug_debugger_message *messageCode, debug_cpu_state *cpuState)
{
        if (!context || !cpuState)
                return B_BAD_VALUE;

        // prepare message
        debug_nub_get_cpu_state message;
        message.reply_port = context->reply_port;
        message.thread = thread;

        // send message
        debug_nub_get_cpu_state_reply reply;
        status_t error = send_debug_message(context, B_DEBUG_MESSAGE_GET_CPU_STATE,
                &message, sizeof(message), &reply, sizeof(reply));
        if (error == B_OK)
                error = reply.error;

        // get state
        if (error == B_OK) {
                *cpuState = reply.cpu_state;
                if (messageCode)
                        *messageCode = reply.message;
        }

        return error;
}


// #pragma mark -

// debug_get_instruction_pointer
status_t
debug_get_instruction_pointer(debug_context *context, thread_id thread,
        void **ip, void **stackFrameAddress)
{
        if (!context || !ip || !stackFrameAddress)
                return B_BAD_VALUE;

        return arch_debug_get_instruction_pointer(context, thread, ip,
                stackFrameAddress);
}

// debug_get_stack_frame
status_t
debug_get_stack_frame(debug_context *context, void *stackFrameAddress,
        debug_stack_frame_info *stackFrameInfo)
{
        if (!context || !stackFrameAddress || !stackFrameInfo)
                return B_BAD_VALUE;

        return arch_debug_get_stack_frame(context, stackFrameAddress,
                stackFrameInfo);
}


// #pragma mark -

// debug_create_symbol_lookup_context
status_t
debug_create_symbol_lookup_context(team_id team, image_id image,
        debug_symbol_lookup_context **_lookupContext)
{
        if (team < 0 || !_lookupContext)
                return B_BAD_VALUE;

        // create the lookup context
        debug_symbol_lookup_context *lookupContext
                = new(std::nothrow) debug_symbol_lookup_context;
        if (lookupContext == NULL)
                return B_NO_MEMORY;
        ObjectDeleter<debug_symbol_lookup_context> contextDeleter(lookupContext);

        // create and init symbol lookup
        SymbolLookup *lookup = new(std::nothrow) SymbolLookup(team, image);
        if (lookup == NULL)
                return B_NO_MEMORY;
        ObjectDeleter<SymbolLookup> lookupDeleter(lookup);

        try {
                status_t error = lookup->Init();
                if (error != B_OK)
                        return error;
        } catch (BPrivate::Debug::Exception exception) {
                return exception.Error();
        }

        // everything went fine: return the result
        lookupContext->lookup = lookup;
        *_lookupContext = lookupContext;
        contextDeleter.Detach();
        lookupDeleter.Detach();

        return B_OK;
}

// debug_delete_symbol_lookup_context
void
debug_delete_symbol_lookup_context(debug_symbol_lookup_context *lookupContext)
{
        if (lookupContext) {
                delete lookupContext->lookup;
                delete lookupContext;
        }
}


// debug_get_symbol
status_t
debug_get_symbol(debug_symbol_lookup_context* lookupContext, image_id image,
        const char* name, int32 symbolType, void** _symbolLocation,
        size_t* _symbolSize, int32* _symbolType)
{
        if (!lookupContext || !lookupContext->lookup)
                return B_BAD_VALUE;
        SymbolLookup* lookup = lookupContext->lookup;

        return lookup->GetSymbol(image, name, symbolType, _symbolLocation,
                _symbolSize, _symbolType);
}


// debug_lookup_symbol_address
status_t
debug_lookup_symbol_address(debug_symbol_lookup_context *lookupContext,
        const void *address, void **baseAddress, char *symbolName,
        int32 symbolNameSize, char *imageName, int32 imageNameSize,
        bool *exactMatch)
{
        if (!lookupContext || !lookupContext->lookup)
                return B_BAD_VALUE;
        SymbolLookup *lookup = lookupContext->lookup;

        // find the symbol
        addr_t _baseAddress;
        const char *_symbolName;
        size_t _symbolNameLen;
        const char *_imageName;
        try {
                status_t error = lookup->LookupSymbolAddress((addr_t)address,
                        &_baseAddress, &_symbolName, &_symbolNameLen, &_imageName,
                        exactMatch);
                if (error != B_OK)
                        return error;
        } catch (BPrivate::Debug::Exception exception) {
                return exception.Error();
        }

        // translate/copy the results
        if (baseAddress)
                *baseAddress = (void*)_baseAddress;

        if (symbolName && symbolNameSize > 0) {
                if (_symbolName && _symbolNameLen > 0) {
                        strlcpy(symbolName, _symbolName,
                                min_c((size_t)symbolNameSize, _symbolNameLen + 1));
                } else
                        symbolName[0] = '\0';
        }

        if (imageName) {
                if (imageNameSize > B_PATH_NAME_LENGTH)
                        imageNameSize = B_PATH_NAME_LENGTH;
                strlcpy(imageName, _imageName, imageNameSize);
        }

        return B_OK;
}


status_t
debug_create_image_symbol_iterator(debug_symbol_lookup_context* lookupContext,
        image_id imageID, debug_symbol_iterator** _iterator)
{
        if (!lookupContext || !lookupContext->lookup)
                return B_BAD_VALUE;
        SymbolLookup *lookup = lookupContext->lookup;

        debug_symbol_iterator* iterator = new(std::nothrow) debug_symbol_iterator;
        if (iterator == NULL)
                return B_NO_MEMORY;

        status_t error;
        try {
                error = lookup->InitSymbolIterator(imageID, *iterator);
        } catch (BPrivate::Debug::Exception exception) {
                error = exception.Error();
        }

        // Work-around for a runtime loader problem. A freshly fork()ed child does
        // still have image_t structures with the parent's image ID's, so we
        // wouldn't find the image in this case.
        if (error != B_OK) {
                // Get the image info and re-try looking with the text base address.
                // Note, that we can't easily check whether the image is part of the
                // target team at all (there's no image_info::team, we'd have to
                // iterate through all images).
                image_info imageInfo;
                error = get_image_info(imageID, &imageInfo);
                if (error == B_OK) {
                        try {
                                error = lookup->InitSymbolIteratorByAddress(
                                        (addr_t)imageInfo.text, *iterator);
                        } catch (BPrivate::Debug::Exception exception) {
                                error = exception.Error();
                        }
                }
        }

        if (error != B_OK) {
                delete iterator;
                return error;
        }

        *_iterator = iterator;
        return B_OK;
}


status_t
debug_create_file_symbol_iterator(const char* path,
        debug_symbol_iterator** _iterator)
{
        if (path == NULL)
                return B_BAD_VALUE;

        // create the iterator
        debug_symbol_iterator* iterator = new(std::nothrow) debug_symbol_iterator;
        if (iterator == NULL)
                return B_NO_MEMORY;
        ObjectDeleter<debug_symbol_iterator> iteratorDeleter(iterator);

        // create the image file
        ImageFile* imageFile = new(std::nothrow) ImageFile;
        if (imageFile == NULL)
                return B_NO_MEMORY;

        // init the iterator
        iterator->image = imageFile;
        iterator->ownsImage = true;
        iterator->currentIndex = -1;

        // init the image file
        status_t error = imageFile->Init(path);
        if (error != B_OK)
                return error;

        iteratorDeleter.Detach();
        *_iterator = iterator;

        return B_OK;
}


void
debug_delete_symbol_iterator(debug_symbol_iterator* iterator)
{
        delete iterator;
}


// debug_next_image_symbol
status_t
debug_next_image_symbol(debug_symbol_iterator* iterator, char* nameBuffer,
        size_t nameBufferLength, int32* _symbolType, void** _symbolLocation,
        size_t* _symbolSize)
{
        if (iterator == NULL || iterator->image == NULL)
                return B_BAD_VALUE;

        const char* symbolName;
        size_t symbolNameLen;
        addr_t symbolLocation;

        try {
                status_t error = iterator->image->NextSymbol(iterator->currentIndex,
                        &symbolName, &symbolNameLen, &symbolLocation, _symbolSize,
                        _symbolType);
                if (error != B_OK)
                        return error;
        } catch (BPrivate::Debug::Exception exception) {
                return exception.Error();
        }

        *_symbolLocation = (void*)symbolLocation;

        if (symbolName != NULL && symbolNameLen > 0) {
                strlcpy(nameBuffer, symbolName,
                        min_c(nameBufferLength, symbolNameLen + 1));
        } else
                nameBuffer[0] = '\0';

        return B_OK;
}


status_t
debug_get_symbol_iterator_image_info(debug_symbol_iterator* iterator,
        image_info* info)
{
        if (iterator == NULL || iterator->image == NULL || info == NULL)
                return B_BAD_VALUE;

        *info = iterator->image->Info();
        return B_OK;
}