Implement IFUNC for PPC.

7 files changed, 187 insertions, 14 deletions

diff --git a/ChangeLog b/ChangeLog
index 5fd0861f23..3359bc20bf 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,4 +1,24 @@
-2009-10-30  Ulrich Drepper  <drepper@redhat.com>
+2009-07-30  Alan Modra  <amodra@bigpond.net.au>
+
+	* elf/elf.h (R_PPC_NUM, R_PPC64_NUM): Delete unused and incorrect.
+	(R_PPC_REL16*): Correct comments.
+	(R_PPC_IRELATIVE, R_PPC64_IRELATIVE, R_PPC64_JMP_IREL): Define.
+	(R_PPC64_REL16, R_PPC64_REL16_LO, R_PPC64_REL16_HI,
+	 R_PPC64_REL16_HA): Define.
+	* sysdeps/powerpc/powerpc32/dl-irel.h: New file.
+	* sysdeps/powerpc/powerpc64/dl-irel.h: New file.
+	* sysdeps/powerpc/powerpc32/dl-machine.c (__elf_machine_fixup_plt):
+	Delete unused "reloc" param.
+	(__process_machine_rela): Handle R_PPC_IRELATIVE.
+	* sysdeps/powerpc/powerpc32/dl-machine.h (__elf_machine_fixup_plt):
+	Delete "reloc" param.
+	(elf_machine_rela): Handle STT_GNU_IFUNC functions and
+	R_PPC_IRELATIVE.
+	* sysdeps/powerpc/powerpc64/dl-machine.h (resolve_ifunc): New function.
+	(elf_machine_rela): Handle STT_GNU_IFUNC functions and new ifunc
+	relocations.
+
+d2009-10-30  Ulrich Drepper  <drepper@redhat.com>
 
 	[BZ #10315]
 	* sysdeps/gnu/netinet/udp.h: Define UDP_CORK, UDP_ENCAP,
diff --git a/elf/elf.h b/elf/elf.h
index ce6de07e91..c772ff41ad 100644
--- a/elf/elf.h
+++ b/elf/elf.h
@@ -2041,9 +2041,6 @@ typedef Elf32_Addr Elf32_Conflict;
 #define R_PPC_GOT_DTPREL16_HI	93 /* half16*	(sym+add)@got@dtprel@h */
 #define R_PPC_GOT_DTPREL16_HA	94 /* half16*	(sym+add)@got@dtprel@ha */
 
-/* Keep this the last entry.  */
-#define R_PPC_NUM		95
-
 /* The remaining relocs are from the Embedded ELF ABI, and are not
    in the SVR4 ELF ABI.  */
 #define R_PPC_EMB_NADDR32	101
@@ -2071,11 +2068,14 @@ typedef Elf32_Addr Elf32_Conflict;
 #define R_PPC_DIAB_RELSDA_HI	184	/* like EMB_RELSDA, but high 16 bit */
 #define R_PPC_DIAB_RELSDA_HA	185	/* like EMB_RELSDA, adjusted high 16 */
 
+/* GNU extension to support local ifunc.  */
+#define R_PPC_IRELATIVE		248
+
 /* GNU relocs used in PIC code sequences.  */
-#define R_PPC_REL16		249	/* word32   (sym-.) */
-#define R_PPC_REL16_LO		250	/* half16   (sym-.)@l */
-#define R_PPC_REL16_HI		251	/* half16   (sym-.)@h */
-#define R_PPC_REL16_HA		252	/* half16   (sym-.)@ha */
+#define R_PPC_REL16		249	/* half16   (sym+add-.) */
+#define R_PPC_REL16_LO		250	/* half16   (sym+add-.)@l */
+#define R_PPC_REL16_HI		251	/* half16   (sym+add-.)@h */
+#define R_PPC_REL16_HA		252	/* half16   (sym+add-.)@ha */
 
 /* This is a phony reloc to handle any old fashioned TOC16 references
    that may still be in object files.  */
@@ -2197,8 +2197,13 @@ typedef Elf32_Addr Elf32_Conflict;
 #define R_PPC64_DTPREL16_HIGHEST 105 /* half16	(sym+add)@dtprel@highest */
 #define R_PPC64_DTPREL16_HIGHESTA 106 /* half16	(sym+add)@dtprel@highesta */
 
-/* Keep this the last entry.  */
-#define R_PPC64_NUM		107
+/* GNU extension to support local ifunc.  */
+#define R_PPC64_JMP_IREL	247
+#define R_PPC64_IRELATIVE	248
+#define R_PPC64_REL16		249	/* half16   (sym+add-.) */
+#define R_PPC64_REL16_LO	250	/* half16   (sym+add-.)@l */
+#define R_PPC64_REL16_HI	251	/* half16   (sym+add-.)@h */
+#define R_PPC64_REL16_HA	252	/* half16   (sym+add-.)@ha */
 
 /* PowerPC64 specific values for the Dyn d_tag field.  */
 #define DT_PPC64_GLINK  (DT_LOPROC + 0)
diff --git a/sysdeps/powerpc/powerpc32/dl-irel.h b/sysdeps/powerpc/powerpc32/dl-irel.h
new file mode 100644
index 0000000000..3f204cd7ae
--- /dev/null
+++ b/sysdeps/powerpc/powerpc32/dl-irel.h
@@ -0,0 +1,45 @@
+/* Machine-dependent ELF indirect relocation inline functions.
+   PowerPC version.
+   Copyright (C) 2009 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, write to the Free
+   Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
+   02111-1307 USA.  */
+
+#ifndef _DL_IREL_H
+#define _DL_IREL_H
+
+#include <stdio.h>
+#include <unistd.h>
+
+#define ELF_MACHINE_IRELA	1
+
+static inline void
+__attribute ((always_inline))
+elf_irela (const Elf32_Rela *reloc)
+{
+  unsigned int r_type = ELF32_R_TYPE (reloc->r_info);
+
+  if (__builtin_expect (r_type == R_PPC_IRELATIVE, 1))
+    {
+      Elf32_Addr *const reloc_addr = (void *) reloc->r_offset;
+      Elf32_Addr value = ((Elf32_Addr (*) (void)) reloc->r_addend) ();
+      *reloc_addr = value;
+    }
+  else
+    __libc_fatal ("unexpected reloc type in static binary");
+}
+
+#endif /* dl-irel.h */
diff --git a/sysdeps/powerpc/powerpc32/dl-machine.c b/sysdeps/powerpc/powerpc32/dl-machine.c
index 71540bd185..ee4c3e0c1c 100644
--- a/sysdeps/powerpc/powerpc32/dl-machine.c
+++ b/sysdeps/powerpc/powerpc32/dl-machine.c
@@ -337,7 +337,7 @@ __elf_machine_runtime_setup (struct link_map *map, int lazy, int profile)
 }
 
 Elf32_Addr
-__elf_machine_fixup_plt (struct link_map *map, const Elf32_Rela *reloc,
+__elf_machine_fixup_plt (struct link_map *map,
 			 Elf32_Addr *reloc_addr, Elf32_Addr finaladdr)
 {
   Elf32_Sword delta = finaladdr - (Elf32_Word) reloc_addr;
@@ -430,6 +430,10 @@ __process_machine_rela (struct link_map *map,
       *reloc_addr = finaladdr;
       return;
 
+    case R_PPC_IRELATIVE:
+      *reloc_addr = ((Elf32_Addr (*) (void)) finaladdr) ();
+      return;
+
     case R_PPC_UADDR32:
       ((char *) reloc_addr)[0] = finaladdr >> 24;
       ((char *) reloc_addr)[1] = finaladdr >> 16;
diff --git a/sysdeps/powerpc/powerpc32/dl-machine.h b/sysdeps/powerpc/powerpc32/dl-machine.h
index a50ffdd1c2..6f8d0f506e 100644
--- a/sysdeps/powerpc/powerpc32/dl-machine.h
+++ b/sysdeps/powerpc/powerpc32/dl-machine.h
@@ -226,7 +226,6 @@ elf_machine_runtime_setup (struct link_map *map,
 
 /* Change the PLT entry whose reloc is 'reloc' to call the actual routine.  */
 extern Elf32_Addr __elf_machine_fixup_plt (struct link_map *map,
-					   const Elf32_Rela *reloc,
 					   Elf32_Addr *reloc_addr,
 					   Elf32_Addr finaladdr);
 
@@ -237,7 +236,7 @@ elf_machine_fixup_plt (struct link_map *map, lookup_t t,
 {
   if (map->l_info[DT_PPC(GOT)] == 0)
     /* Handle old style PLT.  */
-    return __elf_machine_fixup_plt (map, reloc, reloc_addr, finaladdr);
+    return __elf_machine_fixup_plt (map, reloc_addr, finaladdr);
 
   *reloc_addr = finaladdr;
   return finaladdr;
@@ -317,6 +316,11 @@ elf_machine_rela (struct link_map *map, const Elf32_Rela *reloc,
   value = reloc->r_addend;
 #endif
 
+  if (sym != NULL
+      && __builtin_expect (ELFW(ST_TYPE) (sym->st_info) == STT_GNU_IFUNC, 0)
+      && __builtin_expect (sym->st_shndx != SHN_UNDEF, 1))
+    value = ((Elf32_Addr (*) (void)) value) ();
+
   /* A small amount of code is duplicated here for speed.  In libc,
      more than 90% of the relocs are R_PPC_RELATIVE; in the X11 shared
      libraries, 60% are R_PPC_RELATIVE, 24% are R_PPC_GLOB_DAT or
diff --git a/sysdeps/powerpc/powerpc64/dl-irel.h b/sysdeps/powerpc/powerpc64/dl-irel.h
new file mode 100644
index 0000000000..6cded5091d
--- /dev/null
+++ b/sysdeps/powerpc/powerpc64/dl-irel.h
@@ -0,0 +1,58 @@
+/* Machine-dependent ELF indirect relocation inline functions.
+   PowerPC64 version.
+   Copyright (C) 2009 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, write to the Free
+   Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
+   02111-1307 USA.  */
+
+#ifndef _DL_IREL_H
+#define _DL_IREL_H
+
+#include <stdio.h>
+#include <unistd.h>
+
+#define ELF_MACHINE_IRELA	1
+
+typedef struct
+{
+  Elf64_Addr fd_func;
+  Elf64_Addr fd_toc;
+  Elf64_Addr fd_aux;
+} Elf64_FuncDesc;
+
+static inline void
+__attribute ((always_inline))
+elf_irela (const Elf64_Rela *reloc)
+{
+  unsigned int r_type = ELF64_R_TYPE (reloc->r_info);
+
+  if (__builtin_expect (r_type == R_PPC64_IRELATIVE, 1))
+    {
+      Elf64_Addr *const reloc_addr = (void *) reloc->r_offset;
+      Elf64_Addr value = ((Elf64_Addr (*) (void)) reloc->r_addend) ();
+      *reloc_addr = value;
+    }
+  else if (__builtin_expect (r_type == R_PPC64_JMP_IREL, 1))
+    {
+      Elf64_Addr *const reloc_addr = (void *) reloc->r_offset;
+      Elf64_Addr value = ((Elf64_Addr (*) (void)) reloc->r_addend) ();
+      *(Elf64_FuncDesc *) reloc_addr = *(Elf64_FuncDesc *) value;
+    }
+  else
+    __libc_fatal ("unexpected reloc type in static binary");
+}
+
+#endif /* dl-irel.h */
diff --git a/sysdeps/powerpc/powerpc64/dl-machine.h b/sysdeps/powerpc/powerpc64/dl-machine.h
index b674dbef43..8a720ae9c2 100644
--- a/sysdeps/powerpc/powerpc64/dl-machine.h
+++ b/sysdeps/powerpc/powerpc64/dl-machine.h
@@ -526,6 +526,29 @@ elf_machine_tprel (struct link_map *map,
 }
 #endif
 
+/* Call function at address VALUE (an OPD entry) to resolve ifunc relocs.  */
+auto inline Elf64_Addr __attribute__ ((always_inline))
+resolve_ifunc (Elf64_Addr value,
+	       const struct link_map *map, const struct link_map *sym_map)
+{
+  /* The function we are calling may not yet have its opd entry relocated.  */
+  Elf64_FuncDesc opd;
+  if (map != sym_map
+#if !defined RTLD_BOOTSTRAP && defined SHARED
+      /* Bootstrap map doesn't have l_relocated set for it.  */
+      && sym_map != &GL(dl_rtld_map)
+#endif
+      && !sym_map->l_relocated)
+    {
+      Elf64_FuncDesc *func = (Elf64_FuncDesc *) value;
+      opd.fd_func = func->fd_func + sym_map->l_addr;
+      opd.fd_toc = func->fd_toc + sym_map->l_addr;
+      opd.fd_aux = func->fd_aux;
+      value = (Elf64_Addr) &opd;
+    }
+  return ((Elf64_Addr (*) (void)) value) ();
+}
+
 /* Perform the relocation specified by RELOC and SYM (which is fully
    resolved).  MAP is the object containing the reloc.  */
 auto inline void __attribute__ ((always_inline))
@@ -550,11 +573,17 @@ elf_machine_rela (struct link_map *map,
   if (__builtin_expect (r_type == R_PPC64_NONE, 0))
     return;
 
-  /* We need SYM_MAP even in the absence of TLS, for elf_machine_fixup_plt.  */
+  /* We need SYM_MAP even in the absence of TLS, for elf_machine_fixup_plt
+     and STT_GNU_IFUNC.  */
   struct link_map *sym_map = RESOLVE_MAP (&sym, version, r_type);
   Elf64_Addr value = ((sym_map == NULL ? 0 : sym_map->l_addr + sym->st_value)
 		      + reloc->r_addend);
 
+  if (sym != NULL
+      && __builtin_expect (ELFW(ST_TYPE) (sym->st_info) == STT_GNU_IFUNC, 0)
+      && __builtin_expect (sym->st_shndx != SHN_UNDEF, 1))
+    value = resolve_ifunc (value, map, sym_map);
+
   /* For relocs that don't edit code, return.
      For relocs that might edit instructions, break from the switch.  */
   switch (r_type)
@@ -564,6 +593,14 @@ elf_machine_rela (struct link_map *map,
       *reloc_addr = value;
       return;
 
+    case R_PPC64_IRELATIVE:
+      value = resolve_ifunc (value, map, sym_map);
+      *reloc_addr = value;
+      return;
+
+    case R_PPC64_JMP_IREL:
+      value = resolve_ifunc (value, map, sym_map);
+      /* Fall thru */
     case R_PPC64_JMP_SLOT:
 #ifdef RESOLVE_CONFLICT_FIND_MAP
       elf_machine_plt_conflict (reloc_addr, value);