Portability: fix "EOFException: premature end of file" doing ELF on Windows.

OutputFile::read() was bad news; fsync() should work, but was missing.

src/file.cpp

@@ -410,21 +410,16 @@ void OutputFile::seek(off_t off, int whence)
     super::seek(off,whence);
 }
 
-int OutputFile::read(void *buf, int len)
+// WARNING: fsync() does not exist in some Windows environments.
-{
+// This trick works only on UNIX-like systems.
-    InputFile infile;
+//int OutputFile::read(void *buf, int len)
-    infile.open(this->getName(), O_RDONLY);
+//{
-    infile.seek(this->tell(), SEEK_SET);
+//    fsync(_fd);
-    return infile.read(buf, len);
+//    InputFile infile;
-}
+//    infile.open(this->getName(), O_RDONLY);
-
+//    infile.seek(this->tell(), SEEK_SET);
-int OutputFile::readx(void *buf, int len)
+//    return infile.read(buf, len);
-{
+//}
-    InputFile infile;
-    infile.open(this->getName(), O_RDONLY);
-    infile.seek(this->tell(), SEEK_SET);
-    return infile.readx(buf, len);
-}
 
 void OutputFile::set_extent(off_t offset, off_t length)
 {

src/file.h

@@ -141,8 +141,6 @@ public:
     // FIXME - these won't work when using the '--stdout' option
     virtual void seek(off_t off, int whence);
     virtual void rewrite(const void *buf, int len);
-    virtual int read(void *buf, int len);
-    virtual int readx(void *buf, int len);
 
     // util
     static void dump(const char *name, const void *buf, int len, int flags=-1);

src/p_lx_elf.cpp

@@ -196,17 +196,6 @@ PackLinuxElf::~PackLinuxElf()
     delete[] file_image; file_image = NULL;
 }
 
-// Swap the byte ranges  fo[a to b]  and  fo[b to c].
-static void swap_byte_ranges(OutputFile *fo, unsigned a, unsigned b, unsigned c)
-{
-    MemBuffer buf(c - a);
-    fo->seek(a, SEEK_SET);
-    fo->readx(buf, c - a);
-    fo->seek(a, SEEK_SET);
-    fo->rewrite(&buf[b - a], c - b);
-    fo->rewrite(&buf[0], b - a);
-}
-
 void PackLinuxElf::pack3(OutputFile *fo, Filter &ft)
 {
     sz_pack2b = fpad4(fo);  // after headers, all PT_LOAD, gaps
@@ -245,16 +234,28 @@ void PackLinuxElf::pack3(OutputFile *fo, Filter &ft)
     get_te16(&linfo.l_lsize) + len - sz_pack2a));
 
     len = fpad4(fo);
-    // Put the loader in the middle, after the compressed PT_LOADs
-    // and before the compressed gaps (and debuginfo!)
-    // As first written, loader is  fo[sz_pack2b to len],
-    // and gaps and debuginfo are   fo[sz_pack2a to sz_pack2b].
-    swap_byte_ranges(fo, sz_pack2a, sz_pack2b, len);
 }
 
 void PackLinuxElf32::pack3(OutputFile *fo, Filter &ft)
 {
-    super::pack3(fo, ft);
+    super::pack3(fo, ft);  // loader follows compressed PT_LOADs
+    // Then compressed gaps (including debuginfo.)
+    unsigned total_in = 0, total_out = 0;
+    for (unsigned k = 0; k < e_phnum; ++k) {
+        Extent x;
+        x.size = find_LOAD_gap(phdri, k, e_phnum);
+        if (x.size) {
+            x.offset = get_te32(&phdri[k].p_offset) +
+                       get_te32(&phdri[k].p_filesz);
+            packExtent(x, total_in, total_out, 0, fo);
+        }
+    }
+    // write block end marker (uncompressed size 0)
+    b_info hdr; memset(&hdr, 0, sizeof(hdr));
+    set_le32(&hdr.sz_cpr, UPX_MAGIC_LE32);
+    fo->write(&hdr, sizeof(hdr));
+    fpad4(fo);
+
     set_te32(&elfout.phdr[0].p_filesz, sz_pack2 + lsize);
     set_te32(&elfout.phdr[0].p_memsz,  sz_pack2 + lsize);
     if (0!=xct_off) {  // shared library
@@ -331,7 +332,24 @@ void PackLinuxElf32::pack3(OutputFile *fo, Filter &ft)
 
 void PackLinuxElf64::pack3(OutputFile *fo, Filter &ft)
 {
-    super::pack3(fo, ft);
+    super::pack3(fo, ft);  // loader follows compressed PT_LOADs
+    // Then compressed gaps (including debuginfo.)
+    unsigned total_in = 0, total_out = 0;
+    for (unsigned k = 0; k < e_phnum; ++k) {
+        Extent x;
+        x.size = find_LOAD_gap(phdri, k, e_phnum);
+        if (x.size) {
+            x.offset = get_te64(&phdri[k].p_offset) +
+                       get_te64(&phdri[k].p_filesz);
+            packExtent(x, total_in, total_out, 0, fo);
+        }
+    }
+    // write block end marker (uncompressed size 0)
+    b_info hdr; memset(&hdr, 0, sizeof(hdr));
+    set_le32(&hdr.sz_cpr, UPX_MAGIC_LE32);
+    fo->write(&hdr, sizeof(hdr));
+    fpad4(fo);
+
     set_te64(&elfout.phdr[0].p_filesz, sz_pack2 + lsize);
     set_te64(&elfout.phdr[0].p_memsz,  sz_pack2 + lsize);
     if (0!=xct_off) {  // shared library
@@ -2298,7 +2316,7 @@ unsigned PackLinuxElf32::find_LOAD_gap(
     return lo - hi;
 }
 
-void PackLinuxElf32::pack2(OutputFile *fo, Filter &ft)
+int PackLinuxElf32::pack2(OutputFile *fo, Filter &ft)
 {
     Extent x;
     unsigned k;
@@ -2356,17 +2374,15 @@ void PackLinuxElf32::pack2(OutputFile *fo, Filter &ft)
     }
     sz_pack2a = fpad4(fo);
 
+    // Accounting only; ::pack3 will do the compression and output
     for (k = 0; k < e_phnum; ++k) {
-        x.size = find_LOAD_gap(phdri, k, e_phnum);
+        total_in += find_LOAD_gap(phdri, k, e_phnum);
-        if (x.size) {
-            x.offset = get_te32(&phdri[k].p_offset) +
-                       get_te32(&phdri[k].p_filesz);
-            packExtent(x, total_in, total_out, 0, fo);
-        }
     }
 
     if ((off_t)total_in != file_size)
         throwEOFException();
+
+    return 0;  // omit end-of-compression bhdr for now
 }
 
 // Determine length of gap between PT_LOAD phdr[k] and closest PT_LOAD
@@ -2409,7 +2425,7 @@ unsigned PackLinuxElf64::find_LOAD_gap(
     return lo - hi;
 }
 
-void PackLinuxElf64::pack2(OutputFile *fo, Filter &ft)
+int PackLinuxElf64::pack2(OutputFile *fo, Filter &ft)
 {
     Extent x;
     unsigned k;
@@ -2467,17 +2483,15 @@ void PackLinuxElf64::pack2(OutputFile *fo, Filter &ft)
     }
     sz_pack2a = fpad4(fo);
 
-    for (k = 0; k < e_phnum; ++k) {
+    // Accounting only; ::pack3 will do the compression and output
-        x.size = find_LOAD_gap(phdri, k, e_phnum);
+    for (k = 0; k < e_phnum; ++k) { // 
-        if (x.size) {
+        total_in += find_LOAD_gap(phdri, k, e_phnum);
-            x.offset = get_te64(&phdri[k].p_offset) +
-                       get_te64(&phdri[k].p_filesz);
-            packExtent(x, total_in, total_out, 0, fo);
-        }
     }
 
     if ((off_t)total_in != file_size)
         throwEOFException();
+
+    return 0;  // omit end-of-compression bhdr for now
 }
 
 // Filter 0x50, 0x51 assume HostPolicy::isLE

src/p_lx_elf.h

@@ -50,7 +50,7 @@ protected:
     // because they depend on Elf32 or Elf64 data structures, which differ.
 
     virtual void pack1(OutputFile *, Filter &) = 0;  // generate executable header
-    virtual void pack2(OutputFile *, Filter &) = 0;  // append compressed data
+    virtual int  pack2(OutputFile *, Filter &) = 0;  // append compressed data
     virtual void pack3(OutputFile *, Filter &) = 0;  // append loader
     //virtual void pack4(OutputFile *, Filter &) = 0;  // append pack header
 
@@ -111,7 +111,7 @@ protected:
     virtual int  ARM_is_QNX(void);
 
     virtual void pack1(OutputFile *, Filter &);  // generate executable header
-    virtual void pack2(OutputFile *, Filter &);  // append compressed data
+    virtual int  pack2(OutputFile *, Filter &);  // append compressed data
     virtual void pack3(OutputFile *, Filter &);  // append loader
     virtual void pack4(OutputFile *, Filter &);  // append pack header
     virtual void unpack(OutputFile *fo);
@@ -228,7 +228,7 @@ protected:
     virtual int checkEhdr(Elf64_Ehdr const *ehdr) const;
 
     virtual void pack1(OutputFile *, Filter &);  // generate executable header
-    virtual void pack2(OutputFile *, Filter &);  // append compressed data
+    virtual int  pack2(OutputFile *, Filter &);  // append compressed data
     virtual void pack3(OutputFile *, Filter &);  // append loader
     virtual void pack4(OutputFile *, Filter &);  // append pack header
     virtual void unpack(OutputFile *fo);

src/p_lx_interp.cpp

@@ -124,12 +124,12 @@ void PackLinuxElf32x86interp::pack1(OutputFile *fo, Filter &)
 #undef E
 }
 
-void PackLinuxElf32x86interp::pack2(OutputFile *fo, Filter &ft)
+int PackLinuxElf32x86interp::pack2(OutputFile *fo, Filter &ft)
 {
     if (opt->o_unix.make_ptinterp) {
-        return;  // ignore current input file!
+        return 1;  // ignore current input file!
     }
-    super::pack2(fo, ft);
+    return super::pack2(fo, ft);
 }
 
 #undef PAGE_MASK

src/p_lx_interp.h

@@ -54,7 +54,7 @@ public:
 
 protected:
     virtual void pack1(OutputFile *, Filter &);  // generate executable header
-    virtual void pack2(OutputFile *, Filter &);  // append compressed data
+    virtual int  pack2(OutputFile *, Filter &);  // append compressed data
     virtual void pack3(OutputFile *, Filter &);  // build loader
 };
 

src/p_mach.cpp

@@ -899,7 +899,7 @@ void PackMachBase<T>::pack3(OutputFile *fo, Filter &ft)
 }
 
 template <class T>
-void PackMachBase<T>::pack2(OutputFile *fo, Filter &ft)  // append compressed body
+int  PackMachBase<T>::pack2(OutputFile *fo, Filter &ft)  // append compressed body
 {
     unsigned const lc_seg = lc_segment[sizeof(Addr)>>3];
     Extent x;
@@ -977,6 +977,8 @@ void PackMachBase<T>::pack2(OutputFile *fo, Filter &ft)  // append compressed bo
     if ((off_t)total_in != file_size)
         throwEOFException();
     segcmdo.filesize = fo->getBytesWritten();
+
+    return 1;
 }
 
 void PackMachPPC32::pack1_setup_threado(OutputFile *const fo)

src/p_mach.h

@@ -532,7 +532,7 @@ public:
 
     // called by the generic pack()
     virtual void pack1(OutputFile *, Filter &);  // generate executable header
-    virtual void pack2(OutputFile *, Filter &);  // append compressed data
+    virtual int  pack2(OutputFile *, Filter &);  // append compressed data
     virtual void pack3(OutputFile *, Filter &) = 0;  // append loader
     virtual void pack4(OutputFile *, Filter &) = 0;  // append PackHeader
 

src/p_unix.cpp

@@ -130,7 +130,7 @@ int PackUnix::getStrategy(Filter &/*ft*/)
     return (opt->no_filter ? -3 : ((opt->filter > 0) ? -2 : 2));
 }
 
-void PackUnix::pack2(OutputFile *fo, Filter &ft)
+int PackUnix::pack2(OutputFile *fo, Filter &ft)
 {
     // compress blocks
     unsigned total_in = 0;
@@ -224,6 +224,8 @@ void PackUnix::pack2(OutputFile *fo, Filter &ft)
     if ((off_t)total_in != file_size) {
         throwEOFException();
     }
+
+    return 1;  // default: write end-of-compression bhdr next
 }
 
 void
@@ -285,12 +287,13 @@ void PackUnix::pack(OutputFile *fo)
     set_te32(&hbuf.p_blocksize, blocksize);
     fo->write(&hbuf, sizeof(hbuf));
 
-    pack2(fo, ft);  // append the compressed body
+    // append the compressed body
-
+    if (pack2(fo, ft)) {
-    // write block end marker (uncompressed size 0)
+        // write block end marker (uncompressed size 0)
-    b_info hdr; memset(&hdr, 0, sizeof(hdr));
+        b_info hdr; memset(&hdr, 0, sizeof(hdr));
-    set_le32(&hdr.sz_cpr, UPX_MAGIC_LE32);
+        set_le32(&hdr.sz_cpr, UPX_MAGIC_LE32);
-    fo->write(&hdr, sizeof(hdr));
+        fo->write(&hdr, sizeof(hdr));
+    }
 
     pack3(fo, ft);  // append loader
 

src/p_unix.h

@@ -54,7 +54,7 @@ public:
 protected:
     // called by the generic pack()
     virtual void pack1(OutputFile *, Filter &);  // generate executable header
-    virtual void pack2(OutputFile *, Filter &);  // append compressed data
+    virtual int  pack2(OutputFile *, Filter &);  // append compressed data
     virtual void pack3(OutputFile *, Filter &);  // append loader
     virtual void pack4(OutputFile *, Filter &);  // append PackHeader