static int ocVerifyImage_ELF ( ObjectCode* oc );
static int ocGetNames_ELF ( ObjectCode* oc );
static int ocResolve_ELF ( ObjectCode* oc );
-#if defined(powerpc_HOST_ARCH)
+#if defined(powerpc_HOST_ARCH) || defined(x86_64_HOST_ARCH)
static int ocAllocateSymbolExtras_ELF ( ObjectCode* oc );
#endif
#elif defined(OBJFORMAT_PEi386)
#endif
#endif
-#if defined(x86_64_HOST_ARCH) && defined(OBJFORMAT_ELF)
-static void*x86_64_high_symbol( char *lbl, void *addr );
-#endif
+/* on x86_64 we have a problem with relocating symbol references in
+ * code that was compiled without -fPIC. By default, the small memory
+ * model is used, which assumes that symbol references can fit in a
+ * 32-bit slot. The system dynamic linker makes this work for
+ * references to shared libraries by either (a) allocating a jump
+ * table slot for code references, or (b) moving the symbol at load
+ * time (and copying its contents, if necessary) for data references.
+ *
+ * We unfortunately can't tell whether symbol references are to code
+ * or data. So for now we assume they are code (the vast majority
+ * are), and allocate jump-table slots. Unfortunately this will
+ * 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
+ * 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
+ */
+#define X86_64_ELF_NONPIC_HACK 1
/* -----------------------------------------------------------------------------
* Built-in symbols from the RTS
if (val == NULL) {
# if defined(OBJFORMAT_ELF)
-# if defined(x86_64_HOST_ARCH)
- val = dlsym(dl_prog_handle, lbl);
- if (val >= (void *)0x80000000) {
- void *new_val;
- new_val = x86_64_high_symbol(lbl, val);
- IF_DEBUG(linker,debugBelch("lookupSymbol: relocating out of range symbol: %s = %p, now %p\n", lbl, val, new_val));
- return new_val;
- } else {
- return val;
- }
-# else
return dlsym(dl_prog_handle, lbl);
-# endif
# elif defined(OBJFORMAT_MACHO)
# if HAVE_DLFCN_H
/* On OS X 10.3 and later, we use dlsym instead of the old legacy
# if defined(OBJFORMAT_MACHO) && (defined(powerpc_HOST_ARCH) || defined(x86_64_HOST_ARCH))
r = ocAllocateSymbolExtras_MachO ( oc );
if (!r) { return r; }
-# elif defined(OBJFORMAT_ELF) && defined(powerpc_HOST_ARCH)
+# elif defined(OBJFORMAT_ELF) && (defined(powerpc_HOST_ARCH) || defined(x86_64_HOST_ARCH))
r = ocAllocateSymbolExtras_ELF ( oc );
if (!r) { return r; }
#endif
* them right next to the object code itself.
*/
-#if defined(powerpc_HOST_ARCH) || (defined(x86_64_HOST_ARCH) \
- && defined(darwin_TARGET_OS))
+#if defined(powerpc_HOST_ARCH) || defined(x86_64_HOST_ARCH)
/*
ocAllocateSymbolExtras
int pagesize, n, m;
#endif
int aligned;
+#ifndef USE_MMAP
int misalignment = 0;
-#if darwin_HOST_OS
+#ifdef darwin_HOST_OS
misalignment = oc->misalignment;
#endif
+#endif
if( count > 0 )
{
#endif
-#if x86_64_HOST_ARCH
-// On x86_64, 32-bit relocations are often used, which requires that
-// we can resolve a symbol to a 32-bit offset. However, shared
-// libraries are placed outside the 2Gb area, which leaves us with a
-// problem when we need to give a 32-bit offset to a symbol in a
-// shared library.
-//
-// For a function symbol, we can allocate a bounce sequence inside the
-// 2Gb area and resolve the symbol to this. The bounce sequence is
-// simply a long jump instruction to the real location of the symbol.
-//
-// For data references, we're screwed.
-//
-typedef struct {
- unsigned char jmp[8]; /* 6 byte instruction: jmpq *0x00000002(%rip) */
- void *addr;
-} x86_64_bounce;
-
-#define X86_64_BB_SIZE 1024
-
-static x86_64_bounce *x86_64_bounce_buffer = NULL;
-static nat x86_64_bb_next_off;
-
-static void*
-x86_64_high_symbol( char *lbl, void *addr )
-{
- x86_64_bounce *bounce;
-
- if ( x86_64_bounce_buffer == NULL ||
- x86_64_bb_next_off >= X86_64_BB_SIZE ) {
- x86_64_bounce_buffer =
- mmap(NULL, X86_64_BB_SIZE * sizeof(x86_64_bounce),
- PROT_EXEC|PROT_READ|PROT_WRITE,
- MAP_PRIVATE|EXTRA_MAP_FLAGS|MAP_ANONYMOUS, -1, 0);
- if (x86_64_bounce_buffer == MAP_FAILED) {
- barf("x86_64_high_symbol: mmap failed");
- }
- x86_64_bb_next_off = 0;
- }
- bounce = &x86_64_bounce_buffer[x86_64_bb_next_off];
- bounce->jmp[0] = 0xff;
- bounce->jmp[1] = 0x25;
- bounce->jmp[2] = 0x02;
- bounce->jmp[3] = 0x00;
- bounce->jmp[4] = 0x00;
- bounce->jmp[5] = 0x00;
- bounce->addr = addr;
- x86_64_bb_next_off++;
-
- IF_DEBUG(linker, debugBelch("x86_64: allocated bounce entry for %s->%p at %p\n",
- lbl, addr, bounce));
-
- insertStrHashTable(symhash, lbl, bounce);
- return bounce;
-}
-#endif
-
-
/*
* Generic ELF functions
*/
{
StgInt64 off = value - P;
if (off >= 0x7fffffffL || off < -0x80000000L) {
- barf("R_X86_64_PC32 relocation out of range: %s = %p",
- symbol, off);
- }
+#if X86_64_ELF_NONPIC_HACK
+ StgInt64 pltAddress = (StgInt64) &makeSymbolExtra(oc, ELF_R_SYM(info), S)
+ -> jumpIsland;
+ off = pltAddress + A - P;
+#else
+ barf("R_X86_64_PC32 relocation out of range: %s = %p\nRecompile %s with -fPIC.",
+ symbol, off, oc->fileName );
+#endif
+ }
*(Elf64_Word *)P = (Elf64_Word)off;
break;
}
case R_X86_64_32:
if (value >= 0x7fffffffL) {
- barf("R_X86_64_32 relocation out of range: %s = %p\n",
- symbol, value);
- }
+#if X86_64_ELF_NONPIC_HACK
+ StgInt64 pltAddress = (StgInt64) &makeSymbolExtra(oc, ELF_R_SYM(info), S)
+ -> jumpIsland;
+ value = pltAddress + A;
+#else
+ barf("R_X86_64_32 relocation out of range: %s = %p\nRecompile %s with -fPIC.",
+ symbol, value, oc->fileName );
+#endif
+ }
*(Elf64_Word *)P = (Elf64_Word)value;
break;
case R_X86_64_32S:
if ((StgInt64)value > 0x7fffffffL || (StgInt64)value < -0x80000000L) {
- barf("R_X86_64_32S relocation out of range: %s = %p\n",
- symbol, value);
+#if X86_64_ELF_NONPIC_HACK
+ StgInt64 pltAddress = (StgInt64) &makeSymbolExtra(oc, ELF_R_SYM(info), S)
+ -> jumpIsland;
+ value = pltAddress + A;
+#else
+ barf("R_X86_64_32S relocation out of range: %s = %p\nRecompile %s with -fPIC.",
+ symbol, value, oc->fileName );
+#endif
}
*(Elf64_Sword *)P = (Elf64_Sword)value;
break;
+
+ case R_X86_64_GOTPCREL:
+ {
+ StgInt64 gotAddress = (StgInt64) &makeSymbolExtra(oc, ELF_R_SYM(info), S)->addr;
+ StgInt64 off = gotAddress + A - P;
+ *(Elf64_Word *)P = (Elf64_Word)off;
+ break;
+ }
+
+ case R_X86_64_PLT32:
+ {
+ StgInt64 off = value - P;
+ if (off >= 0x7fffffffL || off < -0x80000000L) {
+ StgInt64 pltAddress = (StgInt64) &makeSymbolExtra(oc, ELF_R_SYM(info), S)
+ -> jumpIsland;
+ off = pltAddress + A - P;
+ }
+ *(Elf64_Word *)P = (Elf64_Word)off;
+ break;
+ }
#endif
default:
#endif /* ia64 */
/*
- * PowerPC ELF specifics
+ * PowerPC & X86_64 ELF specifics
*/
-#ifdef powerpc_HOST_ARCH
+#if defined(powerpc_HOST_ARCH) || defined(x86_64_HOST_ARCH)
static int ocAllocateSymbolExtras_ELF( ObjectCode *oc )
{
if( shdr[i].sh_entsize != sizeof( Elf_Sym ) )
{
errorBelch( "The entry size (%d) of the symtab isn't %d\n",
- shdr[i].sh_entsize, sizeof( Elf_Sym ) );
+ (int) shdr[i].sh_entsize, (int) sizeof( Elf_Sym ) );
return 0;
}
projects / ghc-hetmet.git / commitdiff