Support trampoline jumps on powerpc.

* grub-core/kern/dl.c (grub_dl_load_segments) [__powerpc__]: Follow
	__ia64__ path.
	(grub_dl_load_segments): Set mod->sz.
	(grub_dl_flush_cache): Flush whole space occupied by module, not just
	segments.
	* grub-core/kern/ia64/dl.c (nopm): Make const while on it.
	(jump): Likewise.
	* grub-core/kern/powerpc/dl.c (grub_arch_dl_get_tramp_got_size): New
	function.
	(trampoline): New struct.
	(trampoline_template): New const.
	(grub_arch_dl_relocate_symbols): Create trampolines on overflow.
	* include/grub/dl.h (grub_dl): Add sz element.
	[__powerpc__]: Follow __ia64__.
	(GRUB_ARCH_DL_TRAMP_ALIGN): Define on ppc.
	(GRUB_ARCH_DL_GOT_ALIGN): Likewise.
	(GRUB_ARCH_DL_TRAMP_SIZE): Likewise.
	(grub_arch_dl_get_tramp_got_size) [__powerpc__]: New proto.

ChangeLog

@@ -1,3 +1,26 @@
+2011-11-08  Vladimir Serbinenko  <phcoder@gmail.com>
+
+	Support trampoline jumps on powerpc.
+
+	* grub-core/kern/dl.c (grub_dl_load_segments) [__powerpc__]: Follow
+	__ia64__ path.
+	(grub_dl_load_segments): Set mod->sz.
+	(grub_dl_flush_cache): Flush whole space occupied by module, not just
+	segments.
+	* grub-core/kern/ia64/dl.c (nopm): Make const while on it.
+	(jump): Likewise.
+	* grub-core/kern/powerpc/dl.c (grub_arch_dl_get_tramp_got_size): New
+	function.
+	(trampoline): New struct.
+	(trampoline_template): New const.
+	(grub_arch_dl_relocate_symbols): Create trampolines on overflow.
+	* include/grub/dl.h (grub_dl): Add sz element.
+	[__powerpc__]: Follow __ia64__.
+	(GRUB_ARCH_DL_TRAMP_ALIGN): Define on ppc.
+	(GRUB_ARCH_DL_GOT_ALIGN): Likewise.
+	(GRUB_ARCH_DL_TRAMP_SIZE): Likewise.
+	(grub_arch_dl_get_tramp_got_size) [__powerpc__]: New proto.
+
 2011-11-06  Vladimir Serbinenko  <phcoder@gmail.com>
 
 	ZFS crypto support.

grub-core/kern/dl.c

@@ -233,7 +233,7 @@ grub_dl_load_segments (grub_dl_t mod, const Elf_Ehdr *e)
   unsigned i;
   Elf_Shdr *s;
   grub_size_t tsize = 0, talign = 1;
-#ifdef __ia64__
+#if defined (__ia64__) || defined (__powerpc__)
   grub_size_t tramp;
   grub_size_t got;
 #endif
@@ -248,9 +248,9 @@ grub_dl_load_segments (grub_dl_t mod, const Elf_Ehdr *e)
 	talign = s->sh_addralign;
     }
 
-#ifdef __ia64__
+#if defined (__ia64__) || defined (__powerpc__)
   grub_arch_dl_get_tramp_got_size (e, &tramp, &got);
-  tramp *= GRUB_IA64_DL_TRAMP_SIZE;
+  tramp *= GRUB_ARCH_DL_TRAMP_SIZE;
   got *= sizeof (grub_uint64_t);
   tsize += ALIGN_UP (tramp, GRUB_ARCH_DL_TRAMP_ALIGN);
   if (talign < GRUB_ARCH_DL_TRAMP_ALIGN)
@@ -269,6 +269,7 @@ grub_dl_load_segments (grub_dl_t mod, const Elf_Ehdr *e)
   mod->base = grub_memalign (talign, tsize);
   if (!mod->base)
     return grub_errno;
+  mod->sz = tsize;
   ptr = mod->base;
 
 #ifdef GRUB_MACHINE_EMU
@@ -316,7 +317,7 @@ grub_dl_load_segments (grub_dl_t mod, const Elf_Ehdr *e)
 	  mod->segment = seg;
 	}
     }
-#ifdef __ia64__
+#if defined (__ia64__) || defined (__powerpc__)
   ptr = (char *) ALIGN_UP ((grub_addr_t) ptr, GRUB_ARCH_DL_TRAMP_ALIGN);
   mod->tramp = ptr;
   ptr += tramp;
@@ -575,15 +576,9 @@ grub_dl_unref (grub_dl_t mod)
 static void
 grub_dl_flush_cache (grub_dl_t mod)
 {
-  grub_dl_segment_t seg;
-
-  for (seg = mod->segment; seg; seg = seg->next) {
-    if (seg->size) {
   grub_dprintf ("modules", "flushing 0x%lx bytes at %p\n",
-		    (unsigned long) seg->size, seg->addr);
+		(unsigned long) mod->sz, mod->base);
-      grub_arch_sync_caches (seg->addr, seg->size);
+  grub_arch_sync_caches (mod->base, mod->sz);
-    }
-  }
 }
 
 /* Load a module from core memory.  */

grub-core/kern/ia64/dl.c

@@ -104,13 +104,13 @@ add_value_to_slot_21 (grub_addr_t addr, grub_uint32_t value)
     }
 }
 
-static grub_uint8_t nopm[5] =
+static const grub_uint8_t nopm[5] =
   {
     /* [MLX]       nop.m 0x0 */
     0x05, 0x00, 0x00, 0x00, 0x01
   };
 
-static grub_uint8_t jump[0x20] =
+static const grub_uint8_t jump[0x20] =
   {
     /* ld8 r16=[r15],8 */
     0x02, 0x80, 0x20, 0x1e, 0x18, 0x14,

grub-core/kern/powerpc/dl.c

@@ -37,6 +37,65 @@ grub_arch_dl_check_header (void *ehdr)
   return GRUB_ERR_NONE;
 }
 
+void
+grub_arch_dl_get_tramp_got_size (const void *ehdr, grub_size_t *tramp,
+				 grub_size_t *got)
+{
+  const Elf_Ehdr *e = ehdr;
+  const Elf_Shdr *s;
+  Elf_Word entsize;
+  unsigned i;
+
+  *tramp = 0;
+  *got = 0;
+
+  /* Find a symbol table.  */
+  for (i = 0, s = (const Elf_Shdr *) ((const char *) e + e->e_shoff);
+       i < e->e_shnum;
+       i++, s = (const Elf_Shdr *) ((const char *) s + e->e_shentsize))
+    if (s->sh_type == SHT_SYMTAB)
+      break;
+
+  if (i == e->e_shnum)
+    return;
+
+  entsize = s->sh_entsize;
+
+  for (i = 0, s = (const Elf_Shdr *) ((const char *) e + e->e_shoff);
+       i < e->e_shnum;
+       i++, s = (const Elf_Shdr *) ((const char *) s + e->e_shentsize))
+    if (s->sh_type == SHT_RELA)
+      {
+	const Elf_Rela *rel, *max;
+	
+	for (rel = (const Elf_Rela *) ((const char *) e + s->sh_offset),
+	       max = rel + s->sh_size / s->sh_entsize;
+	     rel < max;
+	     rel++)
+	  if (ELF_R_TYPE (rel->r_info) == R_PPC_REL24)
+	    (*tramp)++;
+	
+      }
+
+  return;
+}
+
+/* For low-endian reverse lis and addr_high as well as ori and addr_low. */
+struct trampoline
+{
+  grub_uint32_t lis;
+  grub_uint32_t ori;
+  grub_uint32_t mtctr;
+  grub_uint32_t bctr;
+};
+
+static const struct trampoline trampoline_template = 
+  {
+    0x3c000000,
+    0x60000000,
+    0x7c0903a6,
+    0x4e800420,
+  };
 
 /* Relocate symbols.  */
 grub_err_t
@@ -46,6 +105,7 @@ grub_arch_dl_relocate_symbols (grub_dl_t mod, void *ehdr)
   Elf_Shdr *s;
   Elf_Word entsize;
   unsigned i;
+  struct trampoline *tptr = mod->tramp;
 
   /* Find a symbol table.  */
   for (i = 0, s = (Elf_Shdr *) ((char *) e + e->e_shoff);
@@ -106,7 +166,20 @@ grub_arch_dl_relocate_symbols (grub_dl_t mod, void *ehdr)
 		      Elf_Sword delta = value - (Elf_Word) addr;
 
 		      if (delta << 6 >> 6 != delta)
-			return grub_error (GRUB_ERR_BAD_MODULE, "relocation overflow");
+			{
+			  COMPILE_TIME_ASSERT (sizeof (struct trampoline)
+					       == GRUB_ARCH_DL_TRAMP_SIZE);
+			  grub_memcpy (tptr, &trampoline_template,
+				       sizeof (*tptr));
+			  delta = (grub_uint8_t *) tptr - (grub_uint8_t *) addr;
+			  tptr->lis |= (((value) >> 16) & 0xffff);
+			  tptr->ori |= ((value) & 0xffff);
+			  tptr++;
+			}
+			
+		      if (delta << 6 >> 6 != delta)
+			return grub_error (GRUB_ERR_BAD_MODULE,
+					   "relocation overflow");
 		      *addr = (*addr & 0xfc000003) | (delta & 0x3fffffc);
 		      break;
 		    }

include/grub/dl.h

@@ -136,11 +136,12 @@ struct grub_dl
   Elf_Sym *symtab;
   void (*init) (struct grub_dl *mod);
   void (*fini) (void);
-#ifdef __ia64__
+#if defined (__ia64__) || defined (__powerpc__)
   void *got;
   void *tramp;
 #endif
   void *base;
+  grub_size_t sz;
   struct grub_dl *next;
 };
 typedef struct grub_dl *grub_dl_t;
@@ -176,10 +177,20 @@ void
 grub_ia64_dl_get_tramp_got_size (const void *ehdr, grub_size_t *tramp,
 				 grub_size_t *got);
 
-#ifdef __ia64__
+#if defined (__ia64__)
 #define GRUB_ARCH_DL_TRAMP_ALIGN 16
 #define GRUB_ARCH_DL_GOT_ALIGN 16
 #define grub_arch_dl_get_tramp_got_size grub_ia64_dl_get_tramp_got_size
+#else
+void
+grub_arch_dl_get_tramp_got_size (const void *ehdr, grub_size_t *tramp,
+				 grub_size_t *got);
+#endif
+
+#ifdef __powerpc__
+#define GRUB_ARCH_DL_TRAMP_SIZE 16
+#define GRUB_ARCH_DL_TRAMP_ALIGN 4
+#define GRUB_ARCH_DL_GOT_ALIGN 4
 #endif
 
 #endif