bug in make_hatch_*(); simplify xfind_pages() when MAP_FIXED; update AT_BASE

src/stub/src/i386-linux.elf-main.c

@@ -291,6 +291,9 @@ make_hatch_x86(Elf32_Phdr const *const phdr, unsigned const reloc)
                 * hatch  = escape;
             }
         }
+        else {
+            hatch = 0;
+        }
     }
     return hatch;
 }
@@ -320,6 +323,9 @@ make_hatch_arm(Elf32_Phdr const *const phdr, unsigned const reloc)
             hatch[0]= 0xef90005b;  // syscall __NR_unmap
             hatch[1]= 0xe1a0f00e;  // mov pc,lr
         }
+        else {
+            hatch = 0;
+        }
     }
     return hatch;
 }
@@ -340,9 +346,12 @@ make_hatch_mips(
         )
         {
             hatch[0]= 0x0000000c;  // syscall
-            hatch[1]= 0x03e00008;  // jr $ra
+            hatch[1]= 0x03200008;  // jr $25  # $25 === $t9 === jp
             hatch[2]= 0x00000000;  //   nop
         }
+        else {
+            hatch = 0;
+        }
     }
     return hatch;
 }
@@ -440,9 +449,14 @@ xfind_pages(unsigned mflags, Elf32_Phdr const *phdr, int phnum,
     lo   -= ~page_mask & lo;  // round down to page boundary
     hi    =  page_mask & (hi - lo - page_mask -1);  // page length
     szlo  =  page_mask & (szlo    - page_mask -1);  // page length
+    if (MAP_FIXED & mflags) {
+        addr = (char *)lo;
+    }
+    else {
         addr = mmap((void *)lo, hi, PROT_NONE, mflags, -1, 0);
+        //munmap(szlo + addr, hi - szlo);
+    }
     *p_brk = hi + addr;  // the logical value of brk(0)
-    //mprotect(szlo + addr, hi - szlo, PROT_NONE);  // no access, but keep the frames!
     return (unsigned long)addr - lo;
 }
 
@@ -657,8 +671,9 @@ void *upx_main(
 ERR_LAB
             err_exit(19);
         }
-        entry = do_xmap(fdi, ehdr, 0, av, 0, 0);
+        entry = do_xmap(fdi, ehdr, 0, av, &reloc, 0);
-        //close(fdi);  // FIXME: bug in mipsel gcc 4.1.1
+        auxv_up(av, AT_BASE, reloc);  // uClibc only?
+        close(fdi);
         break;
     }
   }