Added option `--force-execve' which forces the use of the generic

linux/386 format.

committer: mfx <mfx> 977486503 +0000

src/conf.h

@@ -516,6 +516,7 @@ struct options_t {
     } tos;
     struct {
         unsigned blocksize;
+        bool force_execve;          // force the linux/386 execve format
         enum { SCRIPT_MAX = 32 };
         const char *script_name;
     } unix;

src/main.cpp

@@ -637,6 +637,9 @@ static int do_option(int optc, const char *arg)
         getoptvar(&opt->unix.blocksize, 8192u, ~0u);
         break;
     case 661:
+        opt->unix.force_execve = true;
+        break;
+    case 662:
         opt->unix.script_name = "/usr/local/lib/upx/upxX";
         if (mfx_optarg && mfx_optarg[0])
             set_script_name(mfx_optarg,1);
@@ -742,8 +745,9 @@ static const struct mfx_option longopts[] =
     // dos/sys
     // unix
     {"blocksize",        0x31, 0, 660},     // --blocksize=
+    {"force-execve",     0x10, 0, 661},     // force linux/386 execve format
 #if 0
-    {"script",           0x31, 0, 661},     // --script=
+    {"script",           0x31, 0, 662},     // --script=
 #endif
     // watcom/le
     {"le",                  0, 0, 620},     // produce LE output

src/p_lx_elf.cpp

@@ -173,19 +173,13 @@ bool PackLinuxI386elf::canPack()
 
     fi->readx(buf, sizeof(buf));
     fi->seek(0, SEEK_SET);
-    if (0 != memcmp(buf, "\x7f\x45\x4c\x46\x01\x01\x01", 7)) // ELF 32-bit LSB
+    Elf_LE32_Ehdr const *const ehdr = (Elf_LE32_Ehdr const *)buf;
-        return false;
 
     // now check the ELF header
-    Elf_LE32_Ehdr const *const ehdr = (Elf_LE32_Ehdr const *)buf;
+    if (checkEhdr(ehdr) != 0)
-    if (memcmp(buf+8, "FreeBSD", 7) == 0)       // branded as FreeBSD
-        return false;
-    if (ehdr->e_type != 2)                      // executable
-        return false;
-    if (ehdr->e_machine != 3 && ehdr->e_machine != 6) // Intel 80[34]86
-        return false;
-    if (ehdr->e_version != 1)                   // version
         return false;
+
+    // additional requirements for linux/elf386
     if (ehdr->e_ehsize != sizeof(*ehdr)) {
         throwCantPack("invalid Ehdr e_ehsize");
         return false;

src/p_lx_exc.cpp

@@ -88,6 +88,31 @@ int PackLinuxI386::getLoaderPrefixSize() const
 //
 **************************************************************************/
 
+// basic check of an Linux ELF Ehdr
+int PackLinuxI386::checkEhdr(const Elf_LE32_Ehdr *ehdr) const
+{
+    const unsigned char * const buf = ehdr->e_ident;
+
+    // NOTE: ELF executables are now handled by p_lx_elf.cpp.
+    if (memcmp(buf, "\x7f\x45\x4c\x46\x01\x01\x01", 7)) // ELF 32-bit LSB
+        return -1;
+
+    // FIXME: add special checks for uncompresed "vmlinux" kernel
+    // now check the ELF header
+    if (!memcmp(buf+8, "FreeBSD", 7))                   // branded
+        return 1;
+    if (ehdr->e_type != 2)                              // executable
+        return 2;
+    if (ehdr->e_machine != 3 && ehdr->e_machine != 6)   // Intel 80[34]86
+        return 3;
+    if (ehdr->e_version != 1)                           // version
+        return 4;
+
+    // success
+    return 0;
+}
+
+
 bool PackLinuxI386::canPack()
 {
     if (exetype != 0)
@@ -101,25 +126,16 @@ bool PackLinuxI386::canPack()
 
     exetype = 0;
     const unsigned l = get_le32(buf);
-#if 0
+
-    // NOTE: ELF executables are now handled by p_lx_elf.cpp.
+    int elf = checkEhdr(&ehdr);
-    if (!memcmp(buf, "\x7f\x45\x4c\x46\x01\x01\x01", 7)) // ELF 32-bit LSB
+    if (elf >= 0)
     {
-        // FIXME: add special checks for uncompresed "vmlinux" kernel
+        // NOTE: ELF executables are now handled by p_lx_elf.cpp,
-        exetype = 1;
+        //   so we only handle them here if force_execve
-        // now check the ELF header
+        if (elf == 0 && opt->unix.force_execve)
-        if (!memcmp(buf+8, "FreeBSD", 7))               // branded
+            exetype = 1;
-            exetype = 0;
-        if (ehdr.e_type != 2)                           // executable
-            exetype = 0;
-        if (ehdr.e_machine != 3 && ehdr.e_machine != 6) // Intel 80[34]86
-            exetype = 0;
-        if (ehdr.e_version != 1)                        // version
-            exetype = 0;
     }
-    else
+    else if (l == 0x00640107 || l == 0x00640108 || l == 0x0064010b || l == 0x006400cc)
-#endif
-    if (l == 0x00640107 || l == 0x00640108 || l == 0x0064010b || l == 0x006400cc)
     {
         // OMAGIC / NMAGIC / ZMAGIC / QMAGIC
         exetype = 2;

src/p_lx_exc.h

@@ -50,6 +50,8 @@ protected:
     virtual int getLoaderSize() const;
     virtual int getLoaderPrefixSize() const;
 
+    virtual int checkEhdr(const Elf_LE32_Ehdr *ehdr) const;
+
     virtual void patchLoader();
     virtual void patchLoaderChecksum();
     virtual void updateLoader(OutputFile *);

src/packmast.cpp

@@ -185,17 +185,20 @@ static Packer* try_packers(InputFile *f, try_function func)
     //
     // linux
     //
-#if 0
+    if (!opt->unix.force_execve)
-    if (opt->unix.script_name)
     {
-        if ((p = func(new PackLinuxI386sep(f),f)) != NULL)
+#if 0
+        if (opt->unix.script_name)
+        {
+            if ((p = func(new PackLinuxI386sep(f),f)) != NULL)
+                return p;
+        }
+#endif
+        if ((p = func(new PackLinuxI386elf(f),f)) != NULL)
+            return p;
+        if ((p = func(new PackLinuxI386sh(f),f)) != NULL)
             return p;
     }
-#endif
-    if ((p = func(new PackLinuxI386elf(f),f)) != NULL)
-        return p;
-    if ((p = func(new PackLinuxI386sh(f),f)) != NULL)
-        return p;
     if ((p = func(new PackLinuxI386(f),f)) != NULL)
         return p;