Revert "Add a RTS option -xp to load PIC object anywhere in address space"

This reverts commit 5403a8636fe82f971234873564f3a05393b89b7a.

3 files changed, 51 insertions, 56 deletions

diff --git a/rts/linker/Elf.c b/rts/linker/Elf.c
index fe87aed0b0..fd24a92630 100644
--- a/rts/linker/Elf.c
+++ b/rts/linker/Elf.c
@@ -169,8 +169,6 @@ get_shndx_table(Elf_Ehdr* ehdr)
 void
 ocInit_ELF(ObjectCode * oc)
 {
-    ocDeinit_ELF(oc);
-
     oc->info = (struct ObjectCodeFormatInfo*)stgCallocBytes(
             1, sizeof *oc->info,
             "ocInit_Elf(ObjectCodeFormatInfo)");
@@ -320,7 +318,6 @@ ocDeinit_ELF(ObjectCode * oc)
         }
 
         stgFree(oc->info);
-        oc->info = NULL;
     }
 }
 
@@ -757,7 +754,7 @@ ocGetNames_ELF ( ObjectCode* oc )
           start = mem;
           mapped_start = mem;
 #else
-          if (USE_CONTIGUOUS_MMAP || RtsFlags.MiscFlags.linkerAlwaysPic) {
+          if (USE_CONTIGUOUS_MMAP) {
               // already mapped.
               start = oc->image + offset;
               alloc = SECTION_NOMEM;
@@ -1587,6 +1584,9 @@ do_Elf_Rela_relocations ( ObjectCode* oc, char* ehdrC,
 
       case COMPAT_R_X86_64_PC32:
       {
+#if defined(ALWAYS_PIC)
+          barf("R_X86_64_PC32 relocation, but ALWAYS_PIC.");
+#else
           StgInt64 off = value - P;
           if (off != (Elf64_Sword)off && X86_64_ELF_NONPIC_HACK) {
               StgInt64 pltAddress =
@@ -1603,6 +1603,7 @@ do_Elf_Rela_relocations ( ObjectCode* oc, char* ehdrC,
           }
           Elf64_Sword payload = off;
           memcpy((void*)P, &payload, sizeof(payload));
+#endif
           break;
       }
 
@@ -1615,6 +1616,9 @@ do_Elf_Rela_relocations ( ObjectCode* oc, char* ehdrC,
 
       case COMPAT_R_X86_64_32:
       {
+#if defined(ALWAYS_PIC)
+          barf("R_X86_64_32 relocation, but ALWAYS_PIC.");
+#else
           if (value != (Elf64_Word)value && X86_64_ELF_NONPIC_HACK) {
               StgInt64 pltAddress =
                   (StgInt64) &makeSymbolExtra(oc, ELF_R_SYM(info), S)
@@ -1630,11 +1634,15 @@ do_Elf_Rela_relocations ( ObjectCode* oc, char* ehdrC,
           }
           Elf64_Word payload = value;
           memcpy((void*)P, &payload, sizeof(payload));
+#endif
           break;
       }
 
       case COMPAT_R_X86_64_32S:
       {
+#if defined(ALWAYS_PIC)
+          barf("R_X86_64_32S relocation, but ALWAYS_PIC.");
+#else
           if ((StgInt64)value != (Elf64_Sword)value && X86_64_ELF_NONPIC_HACK) {
               StgInt64 pltAddress =
                   (StgInt64) &makeSymbolExtra(oc, ELF_R_SYM(info), S)
@@ -1650,6 +1658,7 @@ do_Elf_Rela_relocations ( ObjectCode* oc, char* ehdrC,
           }
           Elf64_Sword payload = value;
           memcpy((void*)P, &payload, sizeof(payload));
+#endif
           break;
       }
       case COMPAT_R_X86_64_REX_GOTPCRELX:
@@ -1671,6 +1680,9 @@ do_Elf_Rela_relocations ( ObjectCode* oc, char* ehdrC,
 #if defined(dragonfly_HOST_OS)
       case COMPAT_R_X86_64_GOTTPOFF:
       {
+#if defined(ALWAYS_PIC)
+          barf("R_X86_64_GOTTPOFF relocation, but ALWAYS_PIC.");
+#else
         /* determine the offset of S to the current thread's tls
            area
            XXX: Move this to the beginning of function */
@@ -1688,12 +1700,16 @@ do_Elf_Rela_relocations ( ObjectCode* oc, char* ehdrC,
           }
           Elf64_SWord payload = off;
           memcpy((void*)P, &payload, sizeof(payload));
+#endif
           break;
       }
 #endif
 
       case COMPAT_R_X86_64_PLT32:
       {
+#if defined(ALWAYS_PIC)
+          barf("R_X86_64_PLT32 relocation, but ALWAYS_PIC.");
+#else
           StgInt64 off = value - P;
           if (off != (Elf64_Sword)off) {
               StgInt64 pltAddress = (StgInt64) &makeSymbolExtra(oc, ELF_R_SYM(info), S)
@@ -1708,6 +1724,7 @@ do_Elf_Rela_relocations ( ObjectCode* oc, char* ehdrC,
           }
           Elf64_Sword payload = off;
           memcpy((void*)P, &payload, sizeof(payload));
+#endif
           break;
       }
 #endif
diff --git a/rts/linker/MachO.c b/rts/linker/MachO.c
index ff8ef7a1e4..5812e89cda 100644
--- a/rts/linker/MachO.c
+++ b/rts/linker/MachO.c
@@ -99,8 +99,6 @@ bool ocMprotect_MachO( ObjectCode *oc );
 void
 ocInit_MachO(ObjectCode * oc)
 {
-    ocDeinit_MachO(oc);
-
     oc->info = (struct ObjectCodeFormatInfo*)stgCallocBytes(
                 1, sizeof *oc->info,
                 "ocInit_MachO(ObjectCodeFormatInfo)");
@@ -162,19 +160,16 @@ ocInit_MachO(ObjectCode * oc)
 
 void
 ocDeinit_MachO(ObjectCode * oc) {
-    if (oc->info != NULL) {
-        if(oc->info->n_macho_symbols > 0) {
-            stgFree(oc->info->macho_symbols);
-        }
+    if(oc->info->n_macho_symbols > 0) {
+        stgFree(oc->info->macho_symbols);
+    }
 #if defined(aarch64_HOST_ARCH)
-        freeGot(oc);
-        for(int i = 0; i < oc->n_sections; i++) {
-            freeStubs(&oc->sections[i]);
-        }
-#endif
-        stgFree(oc->info);
-        oc->info = NULL;
+    freeGot(oc);
+    for(int i = 0; i < oc->n_sections; i++) {
+        freeStubs(&oc->sections[i]);
     }
+#endif
+    stgFree(oc->info);
 }
 
 static int
diff --git a/rts/linker/SymbolExtras.c b/rts/linker/SymbolExtras.c
index 4c40b10877..88541f44d0 100644
--- a/rts/linker/SymbolExtras.c
+++ b/rts/linker/SymbolExtras.c
@@ -19,12 +19,6 @@
 #include "linker/SymbolExtras.h"
 #include "linker/M32Alloc.h"
 
-#if defined(OBJFORMAT_ELF)
-#  include "linker/Elf.h"
-#elif defined(OBJFORMAT_MACHO)
-#  include "linker/MachO.h"
-#endif
-
 #include <string.h>
 #if RTS_LINKER_USE_MMAP
 #include <sys/mman.h>
@@ -52,24 +46,8 @@
 int ocAllocateSymbolExtras( ObjectCode* oc, int count, int first )
 {
   size_t n;
-  void* oldImage = oc->image;
-
-  if (count > 0) {
-    if (!RTS_LINKER_USE_MMAP) {
-
-      // round up to the nearest 4
-      int aligned = (oc->fileSize + 3) & ~3;
-      int misalignment = oc->misalignment;
 
-      oc->image -= misalignment;
-      oc->image = stgReallocBytes( oc->image,
-                               misalignment +
-                               aligned + sizeof (SymbolExtra) * count,
-                               "ocAllocateSymbolExtras" );
-      oc->image += misalignment;
-
-      oc->symbol_extras = (SymbolExtra *) (oc->image + aligned);
-    } else if (USE_CONTIGUOUS_MMAP || RtsFlags.MiscFlags.linkerAlwaysPic) {
+  if (RTS_LINKER_USE_MMAP && USE_CONTIGUOUS_MMAP) {
       n = roundUpToPage(oc->fileSize);
 
       /* Keep image and symbol_extras contiguous */
@@ -85,37 +63,42 @@ int ocAllocateSymbolExtras( ObjectCode* oc, int count, int first )
           oc->imageMapped = true;
           oc->fileSize = n + (sizeof(SymbolExtra) * count);
           oc->symbol_extras = (SymbolExtra *) (oc->image + n);
-          if (mprotect(new, allocated_size,
-                       PROT_READ | PROT_WRITE | PROT_EXEC) != 0) {
-            sysErrorBelch("unable to protect memory");
+          if(mprotect(new, allocated_size, PROT_READ | PROT_EXEC) != 0) {
+              sysErrorBelch("unable to protect memory");
           }
       }
       else {
           oc->symbol_extras = NULL;
           return 0;
       }
-    } else {
+  }
+  else if( count > 0 ) {
+    if (RTS_LINKER_USE_MMAP) {
+        n = roundUpToPage(oc->fileSize);
+
         oc->symbol_extras = m32_alloc(sizeof(SymbolExtra) * count, 8);
         if (oc->symbol_extras == NULL) return 0;
     }
+    else {
+        // round up to the nearest 4
+        int aligned = (oc->fileSize + 3) & ~3;
+        int misalignment = oc->misalignment;
+
+        oc->image -= misalignment;
+        oc->image = stgReallocBytes( oc->image,
+                                 misalignment +
+                                 aligned + sizeof (SymbolExtra) * count,
+                                 "ocAllocateSymbolExtras" );
+        oc->image += misalignment;
+
+        oc->symbol_extras = (SymbolExtra *) (oc->image + aligned);
+    }
   }
 
   if (oc->symbol_extras != NULL) {
       memset( oc->symbol_extras, 0, sizeof (SymbolExtra) * count );
   }
 
-  // ObjectCodeFormatInfo contains computed addresses based on offset to
-  // image, if the address of image changes, we need to invalidate
-  // the ObjectCodeFormatInfo and recompute it.
-  if (oc->image != oldImage) {
-#if defined(OBJFORMAT_MACHO)
-    ocInit_MachO( oc );
-#endif
-#if defined(OBJFORMAT_ELF)
-    ocInit_ELF( oc );
-#endif
-  }
-
   oc->first_symbol_extra = first;
   oc->n_symbol_extras = count;