unix_main.cpp

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/*
Copyright (C) 2002-2020 UFO: Alien Invasion.

This program is free software; you can redistribute it and/or
modify it under the terms of the GNU General Public License
as published by the Free Software Foundation; either version 2
of the License, or (at your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

See the GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.

*/

#include <unistd.h>
#include <sys/time.h>
#include <stdlib.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <pwd.h>
#include <dlfcn.h>
#include <fcntl.h>
#include <locale.h>
#include <signal.h>
#include <dirent.h>

#include "../../common/common.h"
#include "../system.h"

#ifdef HAVE_EXECINFO_H
#include <execinfo.h>
#define MAX_BACKTRACE_SYMBOLS 50
#endif

#ifdef HAVE_SYS_UTSNAME_H
#include <sys/utsname.h>
#endif

#ifdef HAVE_LINK_H
#include <link.h>
#endif

#ifndef COMPILE_UFO
#undef HAVE_BFD_H
#endif
#include "../../shared/bfd.h"

const char* Sys_GetCurrentUser (void)
{
    static char s_userName[MAX_VAR];
    const struct passwd* p;

    if ((p = getpwuid(getuid())) == nullptr)
        s_userName[0] = '\0';
    else {
        strncpy(s_userName, p->pw_name, sizeof(s_userName));
        s_userName[sizeof(s_userName) - 1] = '\0';
    }
    return s_userName;
}

void Sys_Error (const char* error, ...)
{
    va_list argptr;
    char string[1024];

    Sys_Backtrace();

#ifdef COMPILE_UFO
    Sys_ConsoleShutdown();
#endif

    /* change stdin to non blocking */
    fcntl(0, F_SETFL, fcntl (0, F_GETFL, 0) & ~FNDELAY);

#ifdef COMPILE_MAP
    Mem_Shutdown();
#endif

    va_start(argptr,error);
    Q_vsnprintf(string, sizeof(string), error, argptr);
    va_end(argptr);

    fprintf(stderr, "Error: %s\n", string);

    exit(1);
}

void Sys_Quit (void)
{
#ifdef COMPILE_UFO
    CL_Shutdown();
    Qcommon_Shutdown();
    Sys_ConsoleShutdown();
#elif COMPILE_MAP
    Mem_Shutdown();
#endif

    fcntl(STDIN_FILENO, F_SETFL, fcntl(STDIN_FILENO, F_GETFL, 0) & ~FNDELAY);
    exit(0);
}

#ifdef HAVE_LINK_H
static int Sys_BacktraceLibsCallback (struct dl_phdr_info* info, size_t size, void* data)
{
    FILE* crash = (FILE*)data;

    int end = 0;

    if (!info->dlpi_name || !info->dlpi_name[0])
        return 0;

    for (int j = 0; j < info->dlpi_phnum; j++) {
        end += info->dlpi_phdr[j].p_memsz;
    }

    fprintf(crash, "[0x" UFO_SIZE_T "x-0x" UFO_SIZE_T "x] %s\n", info->dlpi_addr, info->dlpi_addr + end, info->dlpi_name);
    return 0;
}

#ifdef HAVE_BFD_H

/* following code parts are taken from libcairo */

struct file_match {
    const char* file;
    void* address;
    void* base;
    void* hdr;
};

#define BUFFER_MAX (16*1024)
static char g_output[BUFFER_MAX];

static int find_matching_file (struct dl_phdr_info* info, size_t size, void* data)
{
#ifdef ElfW
    typedef ElfW(Phdr) Elf_Phdr;
    typedef ElfW(Addr) Elf_Addr;
#endif

    struct file_match* match = (file_match*)data;
    /* This code is modeled from Gfind_proc_info-lsb.c:callback() from libunwind */
    Elf_Addr const  load_base = info->dlpi_addr;
    Elf_Phdr const* phdr      = info->dlpi_phdr;
    for (long n = info->dlpi_phnum; --n >= 0; phdr++) {
        if (phdr->p_type == PT_LOAD) {
            Elf_Addr vaddr = phdr->p_vaddr + load_base;
            if (match->address >= (void*)vaddr && match->address < (void*)(vaddr + phdr->p_memsz)) {
                /* we found a match */
                match->file = info->dlpi_name;
                match->base = (void*)info->dlpi_addr;
            }
        }
    }
    return 0;
}

static void _backtrace (FILE* crash, void* const* buffer, int size)
{
    struct bfd_set* set = (bfd_set*)calloc(1, sizeof(*set));
    struct output_buffer ob;

    output_init(&ob, g_output, sizeof(g_output));

    bfd_init();

    for (int x = 0; x < size; x++) {
        struct file_match match = {(const char*)buffer[x], nullptr, nullptr, nullptr};
        const char* file = nullptr;
        const char* func = nullptr;
        unsigned line = 0;
        const char* procname;

        dl_iterate_phdr(find_matching_file, &match);
        const unsigned long addr = (char*)buffer[x] - (char*)match.base;

        if (match.file && strlen(match.file))
            procname = match.file;
        else
            procname = "/proc/self/exe";

        struct bfd_ctx* bc = get_bc(&ob, set, procname);
        if (bc) {
            find(bc, addr, &file, &func, &line);
            procname = bc->handle->filename;
        }

        if (func == nullptr) {
            output_print(&ob, "0x%x : %s : %s \n",
                    addr, procname == nullptr ? "unknown" : procname, file == nullptr ? "unknown" : file);
        } else {
            output_print(&ob, "0x%x : %s : %s (%d) : in function (%s) \n",
                    addr, procname == nullptr ? "unknown" : procname, file == nullptr ? "unknown" : file, line, func);
        }
    }

    fprintf(crash, "%s", g_output);

    release_set(set);
}

#endif

#endif

void Sys_Backtrace (void)
{
#ifdef COMPILE_UFO
    Com_BreakIntoDebugger();
#endif

    const char* dumpFile = "crashdump.txt";
    FILE* file = Sys_Fopen(dumpFile, "w");
    FILE* crash = file != nullptr ? file : stderr;

    fprintf(crash, "======start======\n");

#ifdef HAVE_SYS_UTSNAME_H
    struct utsname  info;
    uname(&info);
    fprintf(crash, "OS Info: %s %s %s %s %s\n", info.sysname, info.nodename, info.release, info.version, info.machine);
#endif

    fprintf(crash, BUILDSTRING ", cpu: " CPUSTRING ", version: " UFO_VERSION "\n\n");
    fflush(crash);

#ifdef HAVE_EXECINFO_H
    void* symbols[MAX_BACKTRACE_SYMBOLS];
    const int i = backtrace(symbols, MAX_BACKTRACE_SYMBOLS);
#if defined HAVE_LINK_H && defined HAVE_BFD_H
    _backtrace(crash, symbols, i);
#else
    backtrace_symbols_fd(symbols, i, fileno(crash));
#endif
#endif

#ifdef HAVE_LINK_H
    fprintf(crash, "Loaded libraries:\n");
    dl_iterate_phdr(Sys_BacktraceLibsCallback, crash);
#endif

    fprintf(crash, "======end========\n");

    if (file != nullptr)
        fclose(file);

#ifdef COMPILE_UFO
    Com_UploadCrashDump(dumpFile);
#endif
}