Revert "Batch merge"

This reverts commit 76c8fd674435a652c75a96c85abbf26f1f221876.

8 files changed, 113 insertions, 133 deletions

diff --git a/rts/linker/Elf.c b/rts/linker/Elf.c
index b647d207cb..9ea10d443f 100644
--- a/rts/linker/Elf.c
+++ b/rts/linker/Elf.c
@@ -53,13 +53,11 @@
  * SILENTLY generate crashing code for data references.  This hack is
  * enabled by X86_64_ELF_NONPIC_HACK.
  *
- * One workaround is to use shared Haskell libraries. This is the case
- * when dynamically-linked GHCi is used.
- *
- * Another workaround is to keep the static libraries but compile them
- * with -fPIC -fexternal-dynamic-refs, because that will generate PIC
- * references to data which can be relocated. This is the case when
- * +RTS -xp is passed.
+ * One workaround is to use shared Haskell libraries.  This is
+ * coming.  Another workaround is to keep the static libraries but
+ * compile them with -fPIC, because that will generate PIC references
+ * to data which can be relocated.  The PIC code is still too green to
+ * do this systematically, though.
  *
  * See bug #781
  * See thread http://www.haskell.org/pipermail/cvs-ghc/2007-September/038458.html
@@ -76,7 +74,7 @@
  * Sym*_NeedsProto: the symbol is undefined and we add a dummy
  *                  default proto extern void sym(void);
  */
-#define X86_64_ELF_NONPIC_HACK (!RtsFlags.MiscFlags.linkerAlwaysPic)
+#define X86_64_ELF_NONPIC_HACK 1
 
 #if defined(sparc_HOST_ARCH)
 #  define ELF_TARGET_SPARC  /* Used inside <elf.h> */
@@ -171,8 +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)");
@@ -322,7 +318,6 @@ ocDeinit_ELF(ObjectCode * oc)
         }
 
         stgFree(oc->info);
-        oc->info = NULL;
     }
 }
 
@@ -581,7 +576,7 @@ ocVerifyImage_ELF ( ObjectCode* oc )
 /* Figure out what kind of section it is.  Logic derived from
    Figure 1.14 ("Special Sections") of the ELF document
    ("Portable Formats Specification, Version 1.1"). */
-static SectionKind getSectionKind_ELF( Elf_Shdr *hdr, int *is_bss )
+static int getSectionKind_ELF( Elf_Shdr *hdr, int *is_bss )
 {
     *is_bss = false;
 
@@ -683,31 +678,23 @@ ocGetNames_ELF ( ObjectCode* oc )
       StgWord mapped_size = 0, mapped_offset = 0;
       StgWord size = shdr[i].sh_size;
       StgWord offset = shdr[i].sh_offset;
-      StgWord align = shdr[i].sh_addralign;
 
       if (is_bss && size > 0) {
          /* This is a non-empty .bss section.  Allocate zeroed space for
             it, and set its .sh_offset field such that
             ehdrC + .sh_offset == addr_of_zeroed_space.  */
-#if defined(NEED_GOT) || RTS_LINKER_USE_MMAP
-          if (USE_CONTIGUOUS_MMAP || RtsFlags.MiscFlags.linkerAlwaysPic) {
-              /* The space for bss sections is already preallocated */
-              ASSERT(oc->bssBegin != NULL);
-              alloc = SECTION_NOMEM;
-              start =
-                oc->image + roundUpToAlign(oc->bssBegin - oc->image, align);
-              oc->bssBegin = (char*)start + size;
-              ASSERT(oc->bssBegin <= oc->bssEnd);
-          } else {
-              /* Use mmapForLinker to allocate .bss, otherwise the malloced
-               * address might be out of range for sections that are mmaped.
-               */
-              alloc = SECTION_MMAP;
-              start = mmapForLinker(size, MAP_ANONYMOUS, -1, 0);
-              mapped_start = start;
-              mapped_offset = 0;
-              mapped_size = roundUpToPage(size);
-          }
+#if defined(NEED_GOT)
+          /* always use mmap if we use GOT slots.  Otherwise the malloced
+           * address might be out of range for sections that are mmaped.
+           */
+          alloc = SECTION_MMAP;
+          start = mmap(NULL, size,
+                       PROT_READ | PROT_WRITE | PROT_EXEC,
+                       MAP_ANON | MAP_PRIVATE,
+                       -1, 0);
+          mapped_start = start;
+          mapped_offset = 0;
+          mapped_size = roundUpToPage(size);
 #else
           alloc = SECTION_MALLOC;
           start = stgCallocBytes(1, size, "ocGetNames_ELF(BSS)");
@@ -767,7 +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;
@@ -1598,6 +1585,9 @@ 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 =
@@ -1614,6 +1604,7 @@ do_Elf_Rela_relocations ( ObjectCode* oc, char* ehdrC,
           }
           Elf64_Sword payload = off;
           memcpy((void*)P, &payload, sizeof(payload));
+#endif
           break;
       }
 
@@ -1626,6 +1617,9 @@ 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)
@@ -1641,11 +1635,15 @@ 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)
@@ -1661,6 +1659,7 @@ 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:
@@ -1682,6 +1681,9 @@ 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 */
@@ -1699,12 +1701,16 @@ 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)
@@ -1719,6 +1725,7 @@ do_Elf_Rela_relocations ( ObjectCode* oc, char* ehdrC,
           }
           Elf64_Sword payload = off;
           memcpy((void*)P, &payload, sizeof(payload));
+#endif
           break;
       }
 #endif
@@ -1884,27 +1891,22 @@ int ocRunInit_ELF( ObjectCode *oc )
 
 #if defined(NEED_SYMBOL_EXTRAS)
 
-int ocAllocateExtras_ELF( ObjectCode *oc )
+int ocAllocateSymbolExtras_ELF( ObjectCode *oc )
 {
-  Elf_Ehdr *ehdr = (Elf_Ehdr *) oc->image;
-  Elf_Shdr* shdr = (Elf_Shdr *) ( ((char *)oc->image) + ehdr->e_shoff );
-  Elf_Shdr* symtab = NULL;
-  Elf_Word shnum = elf_shnum(ehdr);
-  int bssSize = 0;
-
-  for (Elf_Word i = 0; i < shnum; ++i) {
-    if(shdr[i].sh_type == SHT_SYMTAB) {
-      symtab = &shdr[i];
-    } else {
-      int isBss = 0;
-      getSectionKind_ELF(&shdr[i], &isBss);
-      if (isBss && shdr[i].sh_size > 0) {
-        bssSize += roundUpToAlign(shdr[i].sh_size, shdr[i].sh_addralign);
-      }
-    }
-  }
+  Elf_Ehdr *ehdr;
+  Elf_Shdr* shdr;
+  Elf_Word i, shnum;
+
+  ehdr = (Elf_Ehdr *) oc->image;
+  shdr = (Elf_Shdr *) ( ((char *)oc->image) + ehdr->e_shoff );
+
+  shnum = elf_shnum(ehdr);
+
+  for( i = 0; i < shnum; i++ )
+    if( shdr[i].sh_type == SHT_SYMTAB )
+      break;
 
-  if (symtab == NULL)
+  if( i == shnum )
   {
     // Not having a symbol table is not in principle a problem.
     // When an object file has no symbols then the 'strip' program
@@ -1914,15 +1916,15 @@ int ocAllocateExtras_ELF( ObjectCode *oc )
     return 1;
   }
 
-  if( symtab->sh_entsize != sizeof( Elf_Sym ) )
+  if( shdr[i].sh_entsize != sizeof( Elf_Sym ) )
   {
     errorBelch( "The entry size (%d) of the symtab isn't %d\n",
-      (int) symtab->sh_entsize, (int) sizeof( Elf_Sym ) );
+      (int) shdr[i].sh_entsize, (int) sizeof( Elf_Sym ) );
 
     return 0;
   }
 
-  return ocAllocateExtras(oc, symtab->sh_size / sizeof( Elf_Sym ), 0, bssSize);
+  return ocAllocateSymbolExtras( oc, shdr[i].sh_size / sizeof( Elf_Sym ), 0 );
 }
 
 #endif /* NEED_SYMBOL_EXTRAS */
diff --git a/rts/linker/Elf.h b/rts/linker/Elf.h
index 30c993b98c..b0d6638e6a 100644
--- a/rts/linker/Elf.h
+++ b/rts/linker/Elf.h
@@ -13,6 +13,6 @@ int ocVerifyImage_ELF    ( ObjectCode* oc );
 int ocGetNames_ELF       ( ObjectCode* oc );
 int ocResolve_ELF        ( ObjectCode* oc );
 int ocRunInit_ELF        ( ObjectCode* oc );
-int ocAllocateExtras_ELF ( ObjectCode *oc );
+int ocAllocateSymbolExtras_ELF( ObjectCode *oc );
 
 #include "EndPrivate.h"
diff --git a/rts/linker/MachO.c b/rts/linker/MachO.c
index ca5befca77..c6a6c28440 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
@@ -187,22 +182,19 @@ resolveImports(
 #if defined(x86_64_HOST_ARCH) || defined(aarch64_HOST_ARCH)
 
 int
-ocAllocateExtras_MachO(ObjectCode* oc)
+ocAllocateSymbolExtras_MachO(ObjectCode* oc)
 {
-    IF_DEBUG(linker, debugBelch("ocAllocateExtras_MachO: start\n"));
+    IF_DEBUG(linker, debugBelch("ocAllocateSymbolExtras_MachO: start\n"));
 
     if (NULL != oc->info->symCmd) {
-        IF_DEBUG(linker,
-            debugBelch("ocAllocateExtras_MachO: allocate %d symbols\n",
-                oc->info->symCmd->nsyms));
-        IF_DEBUG(linker, debugBelch("ocAllocateExtras_MachO: done\n"));
-        return ocAllocateExtras(oc, oc->info->symCmd->nsyms, 0, 0);
+        IF_DEBUG(linker, debugBelch("ocAllocateSymbolExtras_MachO: allocate %d symbols\n", oc->info->symCmd->nsyms));
+        IF_DEBUG(linker, debugBelch("ocAllocateSymbolExtras_MachO: done\n"));
+        return ocAllocateSymbolExtras(oc, oc->info->symCmd->nsyms, 0);
     }
 
-    IF_DEBUG(linker,
-        debugBelch("ocAllocateExtras_MachO: allocated no symbols\n"));
-    IF_DEBUG(linker, debugBelch("ocAllocateExtras_MachO: done\n"));
-    return ocAllocateExtras(oc, 0, 0, 0);
+    IF_DEBUG(linker, debugBelch("ocAllocateSymbolExtras_MachO: allocated no symbols\n"));
+    IF_DEBUG(linker, debugBelch("ocAllocateSymbolExtras_MachO: done\n"));
+    return ocAllocateSymbolExtras(oc,0,0);
 }
 
 #else
diff --git a/rts/linker/MachO.h b/rts/linker/MachO.h
index 4fb58e8668..b495c2b9b1 100644
--- a/rts/linker/MachO.h
+++ b/rts/linker/MachO.h
@@ -13,7 +13,7 @@ int ocGetNames_MachO       ( ObjectCode* oc );
 int ocResolve_MachO        ( ObjectCode* oc );
 int ocRunInit_MachO        ( ObjectCode* oc );
 int machoGetMisalignment( FILE * );
-int ocAllocateExtras_MachO ( ObjectCode* oc );
+int ocAllocateSymbolExtras_MachO ( ObjectCode* oc );
 
 #if defined(powerpc_HOST_ARCH)
 void machoInitSymbolsWithoutUnderscore( void );
diff --git a/rts/linker/PEi386.c b/rts/linker/PEi386.c
index 6cf0d52d39..cc92fa78a2 100644
--- a/rts/linker/PEi386.c
+++ b/rts/linker/PEi386.c
@@ -1778,7 +1778,7 @@ ocGetNames_PEi386 ( ObjectCode* oc )
  * so simply set correct pointer here.
  */
 bool
-ocAllocateExtras_PEi386 ( ObjectCode* oc )
+ocAllocateSymbolExtras_PEi386 ( ObjectCode* oc )
 {
    /* If the ObjectCode was unloaded we don't need a trampoline, it's likely
       an import library so we're discarding it earlier.  */
diff --git a/rts/linker/PEi386.h b/rts/linker/PEi386.h
index 538f132ab5..eb5bec8b78 100644
--- a/rts/linker/PEi386.h
+++ b/rts/linker/PEi386.h
@@ -57,7 +57,7 @@ bool ocRunInit_PEi386     ( ObjectCode *oc );
 bool ocGetNames_PEi386    ( ObjectCode* oc );
 bool ocVerifyImage_PEi386 ( ObjectCode* oc );
 SymbolAddr *lookupSymbol_PEi386(SymbolName *lbl);
-bool ocAllocateExtras_PEi386 ( ObjectCode* oc );
+bool ocAllocateSymbolExtras_PEi386 ( ObjectCode* oc );
 SymbolAddr *lookupSymbolInDLLs ( const SymbolName* lbl );
 /* See Note [mingw-w64 name decoration scheme] */
 /* We use myindex to calculate array addresses, rather than
diff --git a/rts/linker/SymbolExtras.c b/rts/linker/SymbolExtras.c
index a9e4c37967..88541f44d0 100644
--- a/rts/linker/SymbolExtras.c
+++ b/rts/linker/SymbolExtras.c
@@ -19,23 +19,16 @@
 #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>
 #endif /* RTS_LINKER_USE_MMAP */
 
 /*
-  ocAllocateExtras
+  ocAllocateSymbolExtras
 
   Allocate additional space at the end of the object file image to make room
-  for jump islands (powerpc, x86_64, arm), GOT entries (x86_64) and
-  bss sections.
+  for jump islands (powerpc, x86_64, arm) and GOT entries (x86_64).
 
   PowerPC relative branch instructions have a 24 bit displacement field.
   As PPC code is always 4-byte-aligned, this yields a +-32MB range.
@@ -50,30 +43,16 @@
   filled in by makeSymbolExtra below.
 */
 
-int ocAllocateExtras(ObjectCode* oc, int count, int first, int bssSize)
+int ocAllocateSymbolExtras( ObjectCode* oc, int count, int first )
 {
-  void* oldImage = oc->image;
-
-  if (count > 0 || bssSize > 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,
-                               "ocAllocateExtras" );
-      oc->image += misalignment;
-
-      oc->symbol_extras = (SymbolExtra *) (oc->image + aligned);
-    } else if (USE_CONTIGUOUS_MMAP || RtsFlags.MiscFlags.linkerAlwaysPic) {
-      /* Keep image, bssExtras and symbol_extras contiguous */
-      size_t n = roundUpToPage(oc->fileSize);
-      bssSize = roundUpToAlign(bssSize, 8);
-      size_t allocated_size = n + bssSize + (sizeof(SymbolExtra) * count);
+  size_t n;
+
+  if (RTS_LINKER_USE_MMAP && USE_CONTIGUOUS_MMAP) {
+      n = roundUpToPage(oc->fileSize);
+
+      /* Keep image and symbol_extras contiguous */
+
+      size_t allocated_size = n + (sizeof(SymbolExtra) * count);
       void *new = mmapForLinker(allocated_size, MAP_ANONYMOUS, -1, 0);
       if (new) {
           memcpy(new, oc->image, oc->fileSize);
@@ -82,37 +61,44 @@ int ocAllocateExtras(ObjectCode* oc, int count, int first, int bssSize)
           }
           oc->image = new;
           oc->imageMapped = true;
-          oc->fileSize = allocated_size;
-          oc->symbol_extras = (SymbolExtra *) (oc->image + n + bssSize);
-          oc->bssBegin = oc->image + n;
-          oc->bssEnd = oc->image + n + bssSize;
+          oc->fileSize = n + (sizeof(SymbolExtra) * count);
+          oc->symbol_extras = (SymbolExtra *) (oc->image + n);
+          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;
 
diff --git a/rts/linker/SymbolExtras.h b/rts/linker/SymbolExtras.h
index af828e66fa..4974c06e7d 100644
--- a/rts/linker/SymbolExtras.h
+++ b/rts/linker/SymbolExtras.h
@@ -7,7 +7,7 @@
 
 #if defined(NEED_SYMBOL_EXTRAS)
 
-int ocAllocateExtras(ObjectCode* oc, int count, int first, int bssSize);
+int ocAllocateSymbolExtras( ObjectCode* oc, int count, int first );
 
 #if defined(arm_HOST_ARCH)
 SymbolExtra* makeArmSymbolExtra( ObjectCode const* oc,