C++ Segment::buffer方法代码示例

std::string
MemoryMap::segmentTitle(const Segment &segment) {
    std::string s;
    
    s += (segment.accessibility() & READABLE)  !=0 ? "r" : "-";
    s += (segment.accessibility() & WRITABLE)  !=0 ? "w" : "-";
    s += (segment.accessibility() & EXECUTABLE)!=0 ? "x" : "-";
    s += (segment.accessibility() & PRIVATE)   !=0 ? "p" : "-";
    unsigned otherAccess = segment.accessibility() & ~(READABLE|WRITABLE|EXECUTABLE|PRIVATE);

    std::string bufname = segment.buffer()->name();
    if (bufname.find_first_of(" \t\n()")==std::string::npos)
        bufname = "buffer " + bufname;
    s += " at " + (bufname+std::string(12, ' ')).substr(0, 12);

    s += " + " + StringUtility::addrToString(segment.offset());

    if (otherAccess != 0)
        s += " access=" + StringUtility::addrToString(otherAccess, 8*sizeof otherAccess);
    
    if (!segment.name().empty()) {
        static const size_t limit = 100;
        std::string name = escapeString(segment.name());
        if (name.size()>limit)
            name = name.substr(0, limit-3) + "...";
        s += " " + name;
    }
    return s;
}

size_t
MemoryMap::insertFile(const std::string &fileName, rose_addr_t startVa, bool writable, std::string segmentName) {
    if (segmentName.empty())
        segmentName = FileSystem::toString(boost::filesystem::path(fileName).filename());
    Segment segment = Segment::fileInstance(fileName, READABLE | (writable?WRITABLE:0), segmentName);
    AddressInterval fileInterval = AddressInterval::baseSize(startVa, segment.buffer()->size());
    insert(fileInterval, segment);
    return fileInterval.size();
}

//.........这里部分代码省略.........

    // Prepare to read subordinate's memory
    std::string mapsName = "/proc/" + StringUtility::numberToString(pid) + "/maps";
    if (NULL==(local.mapsFile = fopen(mapsName.c_str(), "r")))
        throw insertProcessError(locatorString, "cannot open " + mapsName + ": " + strerror(errno));
    std::string memName = "/proc/" + StringUtility::numberToString(pid) + "/mem";
    if (-1 == (local.memFile = open(memName.c_str(), O_RDONLY)))
        throw insertProcessError(locatorString, "cannot open " + memName + ": " + strerror(errno));

    // Read each line from the /proc/xxx/maps to figure out what memory is mapped in the subordinate process. The format for
    // the part we're interested in is /^([0-9a-f]+)-([0-9a-f]+) ([-r][-w][-x])/ where $1 is the inclusive starting address, $2
    // is the exclusive ending address, and $3 are the permissions.
    int mapsFileLineNumber = 0;
    while (rose_getline(&local.buf, &local.bufsz, local.mapsFile)>0) {
        ++mapsFileLineNumber;

        // Begin address
        char *s=local.buf, *rest=s;
        errno = 0;
        rose_addr_t begin = rose_strtoull(s, &rest, 16);
        if (errno!=0 || rest==s || '-'!=*rest) {
            throw insertProcessError(locatorString, mapsName + " syntax error for beginning address at line " +
                                     StringUtility::numberToString(mapsFileLineNumber) + ": " + local.buf);
        }

        // End address
        s = rest+1;
        rose_addr_t end = rose_strtoull(s, &rest, 16);
        if (errno!=0 || rest==s || ' '!=*rest) {
            throw insertProcessError(locatorString, mapsName + " syntax error for ending address at line " +
                                     StringUtility::numberToString(mapsFileLineNumber) + ": " + local.buf);
        }
        if (begin >= end) {
            throw insertProcessError(locatorString, mapsName + " invalid address range at line " +
                                     StringUtility::numberToString(mapsFileLineNumber) + ": " + local.buf);
        }

        // Access permissions
        s = ++rest;
        if ((s[0]!='r' && s[0]!='-') || (s[1]!='w' && s[1]!='-') || (s[2]!='x' && s[2]!='-')) {
            throw insertProcessError(locatorString, mapsName + " invalid access permissions at line " +
                                     StringUtility::numberToString(mapsFileLineNumber) + ": " + local.buf);
        }
        unsigned accessibility = ('r'==s[0] ? READABLE : 0) | ('w'==s[1] ? WRITABLE : 0) | ('x'==s[2] ? EXECUTABLE : 0);

        // Skip over unused fields
        for (size_t nSpaces=0; nSpaces<4 && *s; ++s) {
            if (isspace(*s))
                ++nSpaces;
        }
        while (isspace(*s)) ++s;

        // Segment name according to the kernel
        std::string kernelSegmentName;
        while (*s && !isspace(*s))
            kernelSegmentName += *s++;

        // Create memory segment, but don't insert it until after we read all the data
        std::string segmentName = "proc:" + StringUtility::numberToString(pid);
        AddressInterval segmentInterval = AddressInterval::baseSize(begin, end-begin);
        Segment segment = Segment::anonymousInstance(segmentInterval.size(), accessibility,
                                                     segmentName + "(" + kernelSegmentName + ")");

        // Copy data from the subordinate process into our memory segment
        if (-1 == lseek(local.memFile, begin, SEEK_SET))
            throw insertProcessError(locatorString, memName + " seek failed: " + strerror(errno));
        size_t nRemain = segmentInterval.size();
        rose_addr_t segmentBufferOffset = 0;
        while (nRemain > 0) {
            uint8_t chunkBuf[8192];
            size_t chunkSize = std::min(nRemain, sizeof chunkBuf);
            ssize_t nRead = ::read(local.memFile, chunkBuf, chunkSize);
            if (-1==nRead) {
                if (EINTR==errno)
                    continue;
                //mlog[WARN] <<strerror(errno) <<" during read from " <<memName <<" for segment " <<kernelSegmentName
                //           <<" at " <<segmentInterval <<"\n";
                segmentName += "[" + boost::to_lower_copy(std::string(strerror(errno))) + "]";
                break;
            } else if (0==nRead) {
                //mlog[WARN] <<"short read from " <<memName <<" for segment " <<kernelSegmentName <<" at " <<segmentInterval <<"\n";
                segmentName += "[short read]";
                break;
            }
            rose_addr_t nWrite = segment.buffer()->write(chunkBuf, segmentBufferOffset, nRead);
            ASSERT_always_require(nWrite == (rose_addr_t)nRead);
            nRemain -= chunkSize;
            segmentBufferOffset += chunkSize;
        }
        if (nRemain > 0) {
            // If a read failed, map only what we could read
            segmentInterval = AddressInterval::baseSize(segmentInterval.least(), segmentInterval.size()-nRemain);
        }

        // Insert segment into memory map
        if (!segmentInterval.isEmpty())
            insert(segmentInterval, segment);
    }
#endif
}