p_armpe.cpp

UPX 源代码

            iats.add(idlls[ic]->iat,esize);
        }
        names.add(idlls[ic]->name,strlen(idlls[ic]->name) + 1 + 1);
    }
    ppi += 4;
    assert(ppi < oimport+soimport);
    soimport = ptr_diff(ppi,oimport);

    if (soimport == 4)
        soimport = 0;

    //OutputFile::dump("x0.imp", oimport, soimport);
    //OutputFile::dump("x1.imp", oimpdlls, soimpdlls);

    unsigned ilen = 0;
    names.flatten();
    if (names.ivnum > 1)
    {
        // The area occupied by the dll and imported names is not continuous
        // so to still support uncompression, I can't zero the iat area.
        // This decreases compression ratio, so FIXME somehow.
        infoWarning("can't remove unneeded imports");
        ilen += sizeof(import_desc) * dllnum;
#if defined(DEBUG)
        if (opt->verbose > 3)
            names.dump();
#endif
        // do some work for the unpacker
        im = im_save;
        for (ic = 0; ic < dllnum; ic++, im++)
        {
            memset(im,FILLVAL,sizeof(*im));
            im->dllname = ptr_diff(idlls[ic]->name,ibuf); // I only need this info
        }
    }
    else
    {
        iats.add(im_save,sizeof(import_desc) * dllnum);
        // zero unneeded data
        iats.clear();
        lookups.clear();
    }
    names.clear();

    iats.add(&names);
    iats.add(&lookups);
    iats.flatten();
    for (ic = 0; ic < iats.ivnum; ic++)
        ilen += iats.ivarr[ic].len;

    info("Imports: original size: %u bytes, preprocessed size: %u bytes",ilen,soimport);
    return names.ivnum == 1 ? names.ivarr[0].start : 0;
}


void PackArmPe::processTls(Interval *) // pass 1
{
    if ((sotls = ALIGN_UP(IDSIZE(PEDIR_TLS),4u)) == 0)
        return;

    // never should happen on wince
    throwCantPack("Static TLS entries found. Send a report please.");
}


/*************************************************************************
// pack
**************************************************************************/

bool PackArmPe::canPack()
{
    if (!readFileHeader() || (ih.cpu != 0x1c0 && ih.cpu != 0x1c2))
        return false;
    use_thumb_stub |= ih.cpu == 0x1c2 || (ih.entry & 1) == 1;
    use_thumb_stub |= (opt->cpu == opt->CPU_8086); // FIXME
    return true;
}


void PackArmPe::buildLoader(const Filter *ft)
{
    const unsigned char *loader = use_thumb_stub ? stub_arm_v4t_wince_pe : stub_arm_v4a_wince_pe;
    unsigned size = use_thumb_stub ? sizeof(stub_arm_v4t_wince_pe) : sizeof(stub_arm_v4a_wince_pe);

    // prepare loader
    initLoader(loader, size);

    if (isdll)
        addLoader("DllStart", NULL);
    addLoader("ExeStart", NULL);

    if (ph.method == M_NRV2E_8)
        addLoader("Call2E", NULL);
    else if (ph.method == M_NRV2B_8)
        addLoader("Call2B", NULL);
    else if (ph.method == M_NRV2D_8)
        addLoader("Call2D", NULL);
    else if (M_IS_LZMA(ph.method))
        addLoader("+40C,CallLZMA", NULL);


    if (ft->id == 0x50)
        addLoader("+40C,Unfilter_0x50", NULL);

    if (sorelocs)
        addLoader("+40C,Relocs", NULL);

    addLoader("+40C,Imports", NULL);
    addLoader("ProcessEnd", NULL);

    if (ph.method == M_NRV2E_8)
        addLoader(".ucl_nrv2e_decompress_8", NULL);
    else if (ph.method == M_NRV2B_8)
        addLoader(".ucl_nrv2b_decompress_8", NULL);
    else if (ph.method == M_NRV2D_8)
        addLoader(".ucl_nrv2d_decompress_8", NULL);
    else if (M_IS_LZMA(ph.method))
        addLoader("+40C,LZMA_DECODE,LZMA_DEC10", NULL);

    addLoader("IDENTSTR,UPX1HEAD", NULL);
}


void PackArmPe::pack(OutputFile *fo)
{
    // FIXME: we need to think about better support for --exact
    if (opt->exact)
        throwCantPackExact();

    const unsigned objs = ih.objects;
    isection = new pe_section_t[objs];
    fi->seek(pe_offset+sizeof(ih),SEEK_SET);
    fi->readx(isection,sizeof(pe_section_t)*objs);

    rvamin = isection[0].vaddr;

    infoHeader("[Processing %s, format %s, %d sections]", fn_basename(fi->getName()), getName(), objs);

    // check the PE header
    // FIXME: add more checks
    if (!opt->force && (
           (ih.cpu != 0x1c0 && ih.cpu != 0x1c2)
        || (ih.opthdrsize != 0xe0)
        || ((ih.flags & EXECUTABLE) == 0)
        || (ih.subsystem != 9)
        || (ih.entry == 0 /*&& !isdll*/)
        || (ih.ddirsentries != 16)
//        || IDSIZE(PEDIR_EXCEPTION) // is this used on arm?
//        || IDSIZE(PEDIR_COPYRIGHT)
       ))
        throwCantPack("unexpected value in PE header (try --force)");

    if (IDSIZE(PEDIR_SEC))
        IDSIZE(PEDIR_SEC) = IDADDR(PEDIR_SEC) = 0;
    //    throwCantPack("compressing certificate info is not supported");

    if (IDSIZE(PEDIR_COMRT))
        throwCantPack(".NET files (win32/net) are not yet supported");

    if (isdll)
        opt->win32_pe.strip_relocs = false;
    else if (opt->win32_pe.strip_relocs < 0)
        opt->win32_pe.strip_relocs = (ih.imagebase >= 0x10000);
    if (opt->win32_pe.strip_relocs)
    {
        if (ih.imagebase < 0x10000)
            throwCantPack("--strip-relocs is not allowed when imagebase < 0x10000");
        else
            ih.flags |= RELOCS_STRIPPED;
    }

    if (memcmp(isection[0].name,"UPX",3) == 0)
        throwAlreadyPackedByUPX();
    if (!opt->force && IDSIZE(15))
        throwCantPack("file is possibly packed/protected (try --force)");
    if (ih.entry && ih.entry < rvamin)
        throwCantPack("run a virus scanner on this file!");
    if (!opt->force && ih.subsystem == 1)
        throwCantPack("subsystem 'native' is not supported (try --force)");
    if (ih.filealign < 0x200)
        throwCantPack("filealign < 0x200 is not yet supported");

    handleStub(fi,fo,pe_offset);
    const unsigned usize = ih.imagesize;
    const unsigned xtrasize = UPX_MAX(ih.datasize, 65536u) + IDSIZE(PEDIR_IMPORT) + IDSIZE(PEDIR_BOUNDIM) + IDSIZE(PEDIR_IAT) + IDSIZE(PEDIR_DELAYIMP) + IDSIZE(PEDIR_RELOC);
    ibuf.alloc(usize + xtrasize);

    // BOUND IMPORT support. FIXME: is this ok?
    fi->seek(0,SEEK_SET);
    fi->readx(ibuf,isection[0].rawdataptr);

    Interval holes(ibuf);

    unsigned ic,jc,overlaystart = 0;
    ibuf.clear(0, usize);
    for (ic = jc = 0; ic < objs; ic++)
    {
        if (isection[ic].rawdataptr && overlaystart < isection[ic].rawdataptr + isection[ic].size)
            overlaystart = ALIGN_UP(isection[ic].rawdataptr + isection[ic].size,ih.filealign);
        if (isection[ic].vsize == 0)
            isection[ic].vsize = isection[ic].size;
        if ((isection[ic].flags & PEFL_BSS) || isection[ic].rawdataptr == 0
            || (isection[ic].flags & PEFL_INFO))
        {
            holes.add(isection[ic].vaddr,isection[ic].vsize);
            continue;
        }
        if (isection[ic].vaddr + isection[ic].size > usize)
            throwCantPack("section size problem");
        if (((isection[ic].flags & (PEFL_WRITE|PEFL_SHARED))
            == (PEFL_WRITE|PEFL_SHARED)))
            if (!opt->force)
                throwCantPack("writeable shared sections not supported (try --force)");
        if (jc && isection[ic].rawdataptr - jc > ih.filealign)
            throwCantPack("superfluous data between sections");
        fi->seek(isection[ic].rawdataptr,SEEK_SET);
        jc = isection[ic].size;
        if (jc > isection[ic].vsize)
            jc = isection[ic].vsize;
        if (isection[ic].vsize == 0) // hack for some tricky programs - may this break other progs?
            jc = isection[ic].vsize = isection[ic].size;
        if (isection[ic].vaddr + jc > ibuf.getSize())
            throwInternalError("buffer too small 1");
        fi->readx(ibuf + isection[ic].vaddr,jc);
        jc += isection[ic].rawdataptr;
    }

    // check for NeoLite
    if (find(ibuf + ih.entry, 64+7, "NeoLite", 7) >= 0)
        throwCantPack("file is already compressed with another packer");

    unsigned overlay = file_size - stripDebug(overlaystart);
    if (overlay >= (unsigned) file_size)
    {
#if 0
        if (overlay < file_size + ih.filealign)
            overlay = 0;
        else if (!opt->force)
            throwNotCompressible("overlay problem (try --force)");
#endif
        overlay = 0;
    }
    checkOverlay(overlay);

    Resource res;
    Interval tlsiv(ibuf);
    Export xport((char*)(unsigned char*)ibuf);

    const unsigned dllstrings = processImports();
    processTls(&tlsiv); // call before processRelocs!!
    processResources(&res);
    processExports(&xport);
    processRelocs();

    //OutputFile::dump("x1", ibuf, usize);

    // some checks for broken linkers - disable filter if necessary
    bool allow_filter = true;
    if (ih.codebase == ih.database
        || ih.codebase + ih.codesize > ih.imagesize
        || (isection[virta2objnum(ih.codebase,isection,objs)].flags & PEFL_CODE) == 0)
        allow_filter = false;

    const unsigned oam1 = ih.objectalign - 1;

    // FIXME: disabled: the uncompressor would not allocate enough memory
    //objs = tryremove(IDADDR(PEDIR_RELOC),objs);

    // FIXME: if the last object has a bss then this won't work
    // newvsize = (isection[objs-1].vaddr + isection[objs-1].size + oam1) &~ oam1;
    // temporary solution:
    unsigned newvsize = (isection[objs-1].vaddr + isection[objs-1].vsize + oam1) &~ oam1;

    //fprintf(stderr,"newvsize=%x objs=%d\n",newvsize,objs);
    if (newvsize + soimport + sorelocs > ibuf.getSize())
         throwInternalError("buffer too small 2");
    memcpy(ibuf+newvsize,oimport,soimport);
    memcpy(ibuf+newvsize+soimport,orelocs,sorelocs);

    cimports = newvsize - rvamin;   // rva of preprocessed imports
    crelocs = cimports + soimport;  // rva of preprocessed fixups

    ph.u_len = newvsize + soimport + sorelocs;

    // some extra data for uncompression support
    unsigned s = 0;
    upx_byte * const p1 = ibuf + ph.u_len;
    memcpy(p1 + s,&ih,sizeof (ih));
    s += sizeof (ih);
    memcpy(p1 + s,isection,ih.objects * sizeof(*isection));
    s += ih.objects * sizeof(*isection);
    if (soimport)
    {
        set_le32(p1 + s,cimports);
        set_le32(p1 + s + 4,dllstrings);
        s += 8;
    }
    if (sorelocs)
    {
        set_le32(p1 + s,crelocs);
        p1[s + 4] = (unsigned char) (big_relocs & 6);
        s += 5;
    }
    if (soresources)
    {
        set_le16(p1 + s,icondir_count);
        s += 2;
    }
    // end of extra data
    set_le32(p1 + s,ptr_diff(p1,ibuf) - rvamin);
    s += 4;
    ph.u_len += s;
    obuf.allocForCompression(ph.u_len);

    // prepare packheader
    ph.u_len -= rvamin;
    // prepare filter
    Filter ft(ph.level);
    ft.buf_len = ih.codesize;
    ft.addvalue = ih.codebase - rvamin;
    // compress
    int filter_strategy = allow_filter ? 0 : -3;

    // disable filters for files with broken headers
    if (ih.codebase + ih.codesize > ph.u_len)
    {
        ft.buf_len = 1;
        filter_strategy = -3;
    }

    // limit stack size needed for runtime decompression
    upx_compress_config_t cconf; cconf.reset();
    cconf.conf_lzma.max_num_probs = 1846 + (768 << 4); // ushort: ~28KB stack
    compressWithFilters(&ft, 2048, &cconf, filter_strategy,
                        ih.codebase, rvamin, 0, NULL, 0);
// info: see buildLoader()
    newvsize = (ph.u_len + rvamin + ph.overlap_overhead + oam1) &~ oam1;
    /*
    if (tlsindex && ((newvsize - ph.c_len - 1024 + oam1) &~ oam1) > tlsindex + 4)
    tlsindex = 0;
    */

    const unsigned lsize = getLoaderSize();

    int identsize = 0;
    const unsigned codesize = getLoaderSection("IDENTSTR",&identsize);
    assert(identsize > 0);
    getLoaderSection("UPX1HEAD",(int*)&ic);
    identsize += ic;

    pe_section_t osection[4];
    // section 0 : bss
    //         1 : [ident + header] + packed_data + unpacker + tls
    //         2 : not compressed data
    //         3 : resource data -- wince 5 needs a new section for this

    // identsplit - number of ident + (upx header) bytes to put into the PE header
    int identsplit = pe_offset + sizeof(osection) + sizeof(oh);
    if ((identsplit & 0x1ff) == 0)
        identsplit = 0;
    else if (((identsplit + identsize) ^ identsplit) < 0x200)
        identsplit = identsize;
    else
        identsplit = ALIGN_GAP(identsplit, 0x200);
    ic = identsize - identsplit;

    const unsigned c_len = ((ph.c_len + ic) & 15) == 0 ? ph.c_len : ph.c_len + 16 - ((ph.c_len + ic) & 15);
    obuf.clear(ph.c_len, c_len - ph.c_len);

    const unsigned s1size = ALIGN_UP(ic + c_len + codesize,4u) + sotls;
    const unsigned s1addr = (newvsize - (ic + c_len) + oam1) &~ oam1;

    const unsigned ncsection = (s1addr + s1size + oam1) &~ oam1;
    const unsigned upxsection = s1addr + ic + c_len;

    Reloc rel(1024); // new relocations are put here
    static const char* symbols_to_relocate[] = {
        "ONAM", "BIMP", "BREL", "FIBE", "FIBS", "ENTR", "DST0", "SRC0"
    };
    for (unsigned s2r = 0; s2r < TABLESIZE(symbols_to_relocate); s2r++)
    {
        unsigned off = linker->getSymbolOffset(symbols_to_relocate[s2r]);
        if (off != 0xdeaddead)
            rel.add(off + upxsection, 3);