dump_vvar.cpp

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <vector>
#include <iostream>
#include <sstream>
#include <fstream>
#include <iterator>

int main(int argc, char **argv) {
    std::string line;
    std::ifstream infile("/proc/self/maps");
    while (std::getline(infile, line)) {
        std::istringstream ss(line);
        std::istream_iterator<std::string> begin(ss);
        std::istream_iterator<std::string> end;
        std::vector<std::string> vstrings(begin, end);
        if (vstrings[vstrings.size()-1] == "[vvar]") {
            int dash = vstrings[0].find('-');
            std::string sstart = vstrings[0].substr(0, dash);
            std::string send = vstrings[0].substr(dash+1, std::string::npos);
            unsigned long start = strtoul(sstart.c_str(), NULL, 16);
            unsigned long end = strtoul(send.c_str(), NULL, 16);
            printf("Found vvar area from %#lx - %#lx, dumping...\n", start, end);
            for (uintptr_t addr = start; addr < end; addr += 16) {
                uint8_t *buf = (uint8_t *)addr;
                printf("%16lx ", addr);
                for (int i = 0; i < 16; i++) printf("%02x ", buf[i]);
                printf("|");
                for (int i = 0; i < 16; i++) printf("%c", ((buf[i] > 31) && (buf[i] < 127)) ? buf[i] : '.');
                printf("|\n");
            }
            // Sleep to let gdb attach
            while (1) sleep(1);
        }
    }
    return 0;
}