/* vi: set sw=4 ts=4: */
/* powerpc shared library loader suppport
 *
 * Copyright (C) 2001-2002,  David A. Schleef
 * Copyright (C) 2003, Erik Andersen
 *
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. The name of the above contributors may not be
 *    used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#if defined (__SUPPORT_LD_DEBUG__)
static const char *_dl_reltypes_tab[] =
	{ "R_PPC_NONE", "R_PPC_ADDR32", "R_PPC_ADDR24", "R_PPC_ADDR16",
	"R_PPC_ADDR16_LO", "R_PPC_ADDR16_HI", "R_PPC_ADDR16_HA",
	"R_PPC_ADDR14", "R_PPC_ADDR14_BRTAKEN", "R_PPC_ADDR14_BRNTAKEN",
	"R_PPC_REL24", "R_PPC_REL14", "R_PPC_REL14_BRTAKEN",
	"R_PPC_REL14_BRNTAKEN", "R_PPC_GOT16", "R_PPC_GOT16_LO",
	"R_PPC_GOT16_HI", "R_PPC_GOT16_HA", "R_PPC_PLTREL24",
	"R_PPC_COPY", "R_PPC_GLOB_DAT", "R_PPC_JMP_SLOT", "R_PPC_RELATIVE",
	"R_PPC_LOCAL24PC", "R_PPC_UADDR32", "R_PPC_UADDR16", "R_PPC_REL32",
	"R_PPC_PLT32", "R_PPC_PLTREL32", "R_PPC_PLT16_LO", "R_PPC_PLT16_HI",
	"R_PPC_PLT16_HA", "R_PPC_SDAREL16", "R_PPC_SECTOFF",
	"R_PPC_SECTOFF_LO", "R_PPC_SECTOFF_HI", "R_PPC_SECTOFF_HA",
};

static const char *
_dl_reltypes(int type)
{
  static char buf[22];  
  const char *str;
  
  if (type >= (int)(sizeof (_dl_reltypes_tab)/sizeof(_dl_reltypes_tab[0])) ||
      NULL == (str = _dl_reltypes_tab[type]))
  {
    str =_dl_simple_ltoa( buf, (unsigned long)(type));
  }
  return str;
}

static 
void debug_sym(Elf32_Sym *symtab,char *strtab,int symtab_index)
{
  if(_dl_debug_symbols)
  {
    if(symtab_index){
      _dl_dprintf(_dl_debug_file, "\n%s\n\tvalue=%x\tsize=%x\tinfo=%x\tother=%x\tshndx=%x",
		  strtab + symtab[symtab_index].st_name,
		  symtab[symtab_index].st_value,
		  symtab[symtab_index].st_size,
		  symtab[symtab_index].st_info,
		  symtab[symtab_index].st_other,
		  symtab[symtab_index].st_shndx);
    }
  }
}

static 
void debug_reloc(Elf32_Sym *symtab,char *strtab, ELF_RELOC *rpnt)
{
  if(_dl_debug_reloc)
  {
    int symtab_index;
    const char *sym;
    symtab_index = ELF32_R_SYM(rpnt->r_info);
    sym = symtab_index ? strtab + symtab[symtab_index].st_name : "sym=0x0";
    
  if(_dl_debug_symbols)
	  _dl_dprintf(_dl_debug_file, "\n\t");
  else
	  _dl_dprintf(_dl_debug_file, "\n%s\n\t", sym);
#ifdef ELF_USES_RELOCA
    _dl_dprintf(_dl_debug_file, "%s\toffset=%x\taddend=%x",
		_dl_reltypes(ELF32_R_TYPE(rpnt->r_info)),
		rpnt->r_offset,
		rpnt->r_addend);
#else
    _dl_dprintf(_dl_debug_file, "%s\toffset=%x\n",
		_dl_reltypes(ELF32_R_TYPE(rpnt->r_info)),
		rpnt->r_offset);
#endif
  }
}
#endif

extern int _dl_linux_resolve(void);

void _dl_init_got(unsigned long *plt,struct elf_resolve *tpnt)
{
	Elf32_Word *tramp;
	Elf32_Word num_plt_entries;
	Elf32_Word data_words;
	Elf32_Word rel_offset_words;
	Elf32_Word dlrr = (Elf32_Word) _dl_linux_resolve;

	//DPRINTF("init_got plt=%x, tpnt=%x\n", (unsigned long)plt,(unsigned long)tpnt);

	num_plt_entries = tpnt->dynamic_info[DT_PLTRELSZ] / sizeof(ELF_RELOC);
	//DPRINTF("n_plt_entries %d\n",n_plt_entries);

	rel_offset_words = PLT_DATA_START_WORDS(num_plt_entries);
	//DPRINTF("rel_offset_words %x\n",rel_offset_words);
	data_words = (Elf32_Word) (plt + rel_offset_words);
	//DPRINTF("data_words %x\n",data_words);

	tpnt->data_words = data_words;

	plt[PLT_LONGBRANCH_ENTRY_WORDS] = OPCODE_ADDIS_HI(11, 11, data_words);
	plt[PLT_LONGBRANCH_ENTRY_WORDS+1] = OPCODE_LWZ(11,data_words,11);

	plt[PLT_LONGBRANCH_ENTRY_WORDS+2] = OPCODE_MTCTR(11);
	plt[PLT_LONGBRANCH_ENTRY_WORDS+3] = OPCODE_BCTR();

	/* [4] */
	/* [5] */
	tramp = (Elf32_Word *) (plt + PLT_TRAMPOLINE_ENTRY_WORDS);

	/* For the long entries, subtract off data_words.  */
	tramp[0] = OPCODE_ADDIS_HI(11,11,-data_words);
	tramp[1] = OPCODE_ADDI(11,11,-data_words);

	/* Multiply index of entry by 3 (in r11).  */
	tramp[2] = OPCODE_SLWI(12,11,1);
	tramp[3] = OPCODE_ADD(11,12,11);
	if (dlrr <= 0x01fffffc || dlrr >= 0xfe000000) {
		/* Load address of link map in r12.  */
		tramp[4] = OPCODE_LI (12, (Elf32_Word) tpnt);
		tramp[5] = OPCODE_ADDIS_HI (12, 12, (Elf32_Word) tpnt);

		/* Call _dl_runtime_resolve.  */
		tramp[6] = OPCODE_BA (dlrr);
	} else {
		/* Get address of _dl_runtime_resolve in CTR.  */
		tramp[4] = OPCODE_LI(12,dlrr);
		tramp[5] = OPCODE_ADDIS_HI(12,12,dlrr);
		tramp[6] = OPCODE_MTCTR(12);

		/* Load address of link map in r12.  */
		tramp[7] = OPCODE_LI(12,(Elf32_Word) tpnt);
		tramp[8] = OPCODE_ADDIS_HI(12,12,(Elf32_Word) tpnt);

		/* Call _dl_runtime_resolve.  */
		tramp[9] = OPCODE_BCTR();
	}
	/* [16] unused */
	/* [17] unused */

	PPC_DCBST(plt);
	PPC_DCBST(plt+4);
	PPC_DCBST(plt+8);
	PPC_DCBST(plt+12);
	PPC_DCBST(plt+16-1);
	PPC_SYNC;
	PPC_ICBI(plt);
	PPC_ICBI(plt+16-1);
	PPC_ISYNC;
}

unsigned long _dl_linux_resolver(struct elf_resolve *tpnt, int reloc_entry)
{
	ELF_RELOC *this_reloc;
	char *strtab;
	Elf32_Sym *symtab;
	ELF_RELOC *rel_addr;
	int symtab_index;
	char *symname;
	Elf32_Addr *reloc_addr;
	Elf32_Addr  finaladdr;
	Elf32_Sword delta;

	rel_addr = (ELF_RELOC *) (tpnt->dynamic_info[DT_JMPREL] + tpnt->loadaddr);

	this_reloc = (void *)rel_addr + reloc_entry;
	symtab_index = ELF32_R_SYM(this_reloc->r_info);

	symtab = (Elf32_Sym *) (tpnt->dynamic_info[DT_SYMTAB] + tpnt->loadaddr);
	strtab = (char *) (tpnt->dynamic_info[DT_STRTAB] + tpnt->loadaddr);
	symname      = strtab + symtab[symtab_index].st_name;

#if defined (__SUPPORT_LD_DEBUG__)
	debug_sym(symtab,strtab,symtab_index);
	debug_reloc(symtab,strtab,this_reloc);

	if (ELF32_R_TYPE(this_reloc->r_info) != R_PPC_JMP_SLOT) {
		_dl_dprintf(2, "%s: Incorrect relocation type in jump relocation\n", _dl_progname);
		_dl_exit(1);
	};
#endif

	/* Address of dump instruction to fix up */
	reloc_addr = (Elf32_Addr *) (tpnt->loadaddr + this_reloc->r_offset);

#if defined (__SUPPORT_LD_DEBUG__)
	if(_dl_debug_reloc && _dl_debug_detail)
		_dl_dprintf(_dl_debug_file, "\n\tResolving symbol %s %x --> ", symname, (Elf32_Addr)reloc_addr);
#endif

	/* Get the address of the GOT entry */
	finaladdr = (Elf32_Addr) _dl_find_hash(strtab + symtab[symtab_index].st_name, 
						tpnt->symbol_scope, tpnt, resolver);
	if (!finaladdr) {
		_dl_dprintf(2, "%s: can't resolve symbol '%s'\n", _dl_progname, symname);
		_dl_exit(1);
	};

#if defined (__SUPPORT_LD_DEBUG__)
	if(_dl_debug_reloc && _dl_debug_detail)
		_dl_dprintf(_dl_debug_file, "%x\n", finaladdr);
#endif
	delta = finaladdr - (Elf32_Word)reloc_addr;
	if (delta<<6>>6 == delta) {
		*reloc_addr = OPCODE_B(delta);
	} else if (finaladdr <= 0x01fffffc || finaladdr >= 0xfe000000) {
		*reloc_addr = OPCODE_BA (finaladdr);
	} else {
		/* Warning: we don't handle double-sized PLT entries */
		Elf32_Word *plt, *data_words, index, offset;

		plt = (Elf32_Word *)(tpnt->dynamic_info[DT_PLTGOT] + tpnt->loadaddr);
		offset = reloc_addr - plt;
		index = (offset - PLT_INITIAL_ENTRY_WORDS)/2;
		data_words = (Elf32_Word *)tpnt->data_words;
		reloc_addr += 1;

		data_words[index] = finaladdr;
		PPC_SYNC;
		*reloc_addr =  OPCODE_B ((PLT_LONGBRANCH_ENTRY_WORDS - (offset+1)) * 4);
	}

	/* instructions were modified */
	PPC_DCBST(reloc_addr);
	PPC_SYNC;
	PPC_ICBI(reloc_addr);
	PPC_ISYNC;

	return finaladdr;
}

static int
_dl_parse(struct elf_resolve *tpnt, struct dyn_elf *scope,
	  unsigned long rel_addr, unsigned long rel_size,
	  int (*reloc_fnc) (struct elf_resolve *tpnt, struct dyn_elf *scope,
			    ELF_RELOC *rpnt, Elf32_Sym *symtab, char *strtab))
{
	unsigned int i;
	char *strtab;
	Elf32_Sym *symtab;
	ELF_RELOC *rpnt;
	int symtab_index;

	/* Now parse the relocation information */
	rpnt = (ELF_RELOC *)(intptr_t) (rel_addr + tpnt->loadaddr);
	rel_size = rel_size / sizeof(ELF_RELOC);

	symtab = (Elf32_Sym *)(intptr_t) (tpnt->dynamic_info[DT_SYMTAB] + tpnt->loadaddr);
	strtab = (char *) (tpnt->dynamic_info[DT_STRTAB] + tpnt->loadaddr);

	  for (i = 0; i < rel_size; i++, rpnt++) {
	        int res;
	    
		symtab_index = ELF32_R_SYM(rpnt->r_info);
		
		/* When the dynamic linker bootstrapped itself, it resolved some symbols.
		   Make sure we do not do them again */
		if (!symtab_index && tpnt->libtype == program_interpreter)
			continue;
		if (symtab_index && tpnt->libtype == program_interpreter &&
		    _dl_symbol(strtab + symtab[symtab_index].st_name))
			continue;

#if defined (__SUPPORT_LD_DEBUG__)
		debug_sym(symtab,strtab,symtab_index);
		debug_reloc(symtab,strtab,rpnt);
#endif

		res = reloc_fnc (tpnt, scope, rpnt, symtab, strtab);

		if (res==0) continue;

		_dl_dprintf(2, "\n%s: ",_dl_progname);
		
		if (symtab_index)
		  _dl_dprintf(2, "symbol '%s': ", strtab + symtab[symtab_index].st_name);
		  
		if (res <0)
		{
		        int reloc_type = ELF32_R_TYPE(rpnt->r_info);
#if defined (__SUPPORT_LD_DEBUG__)
			_dl_dprintf(2, "can't handle reloc type %s\n ", _dl_reltypes(reloc_type));
#else
			_dl_dprintf(2, "can't handle reloc type %x\n", reloc_type);
#endif			
			_dl_exit(-res);
		}
		else if (res >0)
		{
			_dl_dprintf(2, "can't resolve symbol\n");
			return res;
		}
	  }
	  return 0;
}

static int
_dl_do_lazy_reloc (struct elf_resolve *tpnt, struct dyn_elf *scope,
		   ELF_RELOC *rpnt, Elf32_Sym *symtab, char *strtab)
{
	Elf32_Addr *reloc_addr;
	Elf32_Word *plt, index, offset;

	(void)scope;
	(void)symtab;
	(void)strtab;

	reloc_addr = (Elf32_Addr *)(tpnt->loadaddr + rpnt->r_offset);
#if defined (__SUPPORT_LD_DEBUG__)
	if (ELF32_R_TYPE(rpnt->r_info) != R_PPC_JMP_SLOT) {
		_dl_dprintf(2, "Reloc type != R_PPC_JMP_SLOT. Type is 0x%x\n", ELF32_R_TYPE(rpnt->r_info));
		return -1;
	}
#endif
	plt = (Elf32_Word *)(tpnt->dynamic_info[DT_PLTGOT] + tpnt->loadaddr);
	offset = reloc_addr - plt;
	index = (offset - PLT_INITIAL_ENTRY_WORDS)/2;
	reloc_addr[0] = OPCODE_LI(11,index*4);
	reloc_addr[1] = OPCODE_B((PLT_TRAMPOLINE_ENTRY_WORDS + 2 - (offset+1)) * 4);

	/* instructions were modified */
	PPC_DCBST(reloc_addr);
	PPC_DCBST(reloc_addr+1);
	PPC_SYNC;
	PPC_ICBI(reloc_addr);
	PPC_ICBI(reloc_addr+1);
	PPC_ISYNC;

#if defined (__SUPPORT_LD_DEBUG__)
	if(_dl_debug_reloc && _dl_debug_detail)
		_dl_dprintf(_dl_debug_file, "\tpatched: %x", reloc_addr);
#endif
	return 0;
}

static int
_dl_do_reloc (struct elf_resolve *tpnt,struct dyn_elf *scope,
	      ELF_RELOC *rpnt, Elf32_Sym *symtab, char *strtab)
{
	int reloc_type;
	int symtab_index;
	char *symname;
	Elf32_Addr *reloc_addr;
	Elf32_Addr finaladdr;

	unsigned long symbol_addr;
#if defined (__SUPPORT_LD_DEBUG__)
	unsigned long old_val;
#endif
	reloc_addr   = (Elf32_Addr *)(intptr_t) (tpnt->loadaddr + (unsigned long) rpnt->r_offset);
	reloc_type   = ELF32_R_TYPE(rpnt->r_info);
	if (reloc_type == R_PPC_RELATIVE) {
		*reloc_addr = tpnt->loadaddr + rpnt->r_addend;
		return 0;
	}
	if (reloc_type == R_PPC_NONE || reloc_type == R_PPC_COPY) /*  R_PPC_COPY is handled later */
		return 0;
	symtab_index = ELF32_R_SYM(rpnt->r_info);
	symname      = strtab + symtab[symtab_index].st_name;

	symbol_addr = (unsigned long) _dl_find_hash(symname, scope, 
						    (reloc_type == R_PPC_JMP_SLOT ? tpnt : NULL), symbolrel);
	/*
	 * We want to allow undefined references to weak symbols - this might
	 * have been intentional.  We should not be linking local symbols
	 * here, so all bases should be covered.
	 */
	if (!symbol_addr && ELF32_ST_BIND(symtab[symtab_index].st_info) == STB_GLOBAL) {
#if defined (__SUPPORT_LD_DEBUG__)
		_dl_dprintf(2, "\tglobal symbol '%s' already defined in '%s', rel type: %s\n",
			    symname, tpnt->libname, _dl_reltypes(reloc_type));
#endif
		return 0;
	}
#if defined (__SUPPORT_LD_DEBUG__)
	old_val = *reloc_addr;
#endif
	finaladdr = (Elf32_Addr) (symbol_addr + rpnt->r_addend);

	switch (reloc_type) {
	case R_PPC_ADDR32:
	case R_PPC_GLOB_DAT:
		*reloc_addr = finaladdr;
		return 0; /* No code code modified */
		break;
	case R_PPC_JMP_SLOT:
	{
		Elf32_Sword delta = finaladdr - (Elf32_Word)reloc_addr;
		
		if (delta<<6>>6 == delta) {
			*reloc_addr = OPCODE_B(delta);
		} else if (finaladdr <= 0x01fffffc || finaladdr >= 0xfe000000) {
			*reloc_addr = OPCODE_BA (finaladdr);
		} else {
			/* Warning: we don't handle double-sized PLT entries */
			Elf32_Word *plt, *data_words, index, offset;

			plt = (Elf32_Word *)(tpnt->dynamic_info[DT_PLTGOT] + tpnt->loadaddr);
			offset = reloc_addr - plt;
			index = (offset - PLT_INITIAL_ENTRY_WORDS)/2;
			data_words = (Elf32_Word *)tpnt->data_words;

			data_words[index] = finaladdr;
			reloc_addr[0] = OPCODE_LI(11,index*4);
			reloc_addr[1] = OPCODE_B((PLT_LONGBRANCH_ENTRY_WORDS - (offset+1)) * 4);

			/* instructions were modified */
			PPC_DCBST(reloc_addr+1);
			PPC_SYNC;
			PPC_ICBI(reloc_addr+1);
		}
		break;
	}
	case R_PPC_COPY:
		/* This does not work yet, R_PPC_COPY is handled later, see if statemet above */
		if (symbol_addr) {
#if defined (__SUPPORT_LD_DEBUG__)
			if(_dl_debug_move)
				_dl_dprintf(_dl_debug_file,"\n%s move %x bytes from %x to %x",
					    symname, symtab[symtab_index].st_size,
					    symbol_addr, symtab[symtab_index].st_value);
#endif
			_dl_memcpy((char *) reloc_addr, (char *) finaladdr, symtab[symtab_index].st_size);
		}
		return 0; /* No code code modified */
		break;
	case R_PPC_ADDR16_HA:
		*(short *)reloc_addr = (finaladdr + 0x8000)>>16;
		break;
	case R_PPC_ADDR16_HI:
		*(short *)reloc_addr = finaladdr >> 16;
		break;
	case R_PPC_ADDR16_LO:
		*(short *)reloc_addr = finaladdr;
		break;
	case R_PPC_REL24:
	{
		Elf32_Sword delta = finaladdr - (Elf32_Word)reloc_addr;
		if(delta<<6>>6 != delta){
			_dl_dprintf(2, "%s: symbol '%s' R_PPC_REL24 is out of range.\n\tCompile shared libraries with -fPIC!\n",
				    _dl_progname, symname);
			_dl_exit(1);
		}
		*reloc_addr = (*reloc_addr & 0xfc000003) | (delta & 0x3fffffc);
		break;
	}
	default:
		_dl_dprintf(2, "%s: can't handle reloc type ", _dl_progname);
#if defined (__SUPPORT_LD_DEBUG__)
		_dl_dprintf(2, "%s ", _dl_reltypes[reloc_type]);
#endif
		if (symtab_index)
			_dl_dprintf(2, "'%s'\n", strtab + symtab[symtab_index].st_name);
		return -1;
	};

	/* instructions were modified */
	PPC_DCBST(reloc_addr);
	PPC_SYNC;
	PPC_ICBI(reloc_addr);
	PPC_ISYNC;
#if defined (__SUPPORT_LD_DEBUG__)
	if(_dl_debug_reloc && _dl_debug_detail)
		_dl_dprintf(_dl_debug_file, "\tpatched: %x ==> %x @ %x", old_val, *reloc_addr, reloc_addr);
#endif
	return 0;
}

/* This is done as a separate step, because there are cases where
   information is first copied and later initialized.  This results in
   the wrong information being copied.  Someone at Sun was complaining about
   a bug in the handling of _COPY by SVr4, and this may in fact be what he
   was talking about.  Sigh. */
static int
_dl_do_copy (struct elf_resolve *tpnt, struct dyn_elf *scope,
	     ELF_RELOC *rpnt, Elf32_Sym *symtab, char *strtab)
{
	int reloc_type;
	int symtab_index;
	unsigned long *reloc_addr;
	unsigned long symbol_addr;
	int goof = 0;
	char *symname;
	  
	reloc_addr = (unsigned long *)(intptr_t) (tpnt->loadaddr + (unsigned long) rpnt->r_offset);
	reloc_type = ELF32_R_TYPE(rpnt->r_info);
	if (reloc_type != R_PPC_COPY) 
		return 0;
	symtab_index = ELF32_R_SYM(rpnt->r_info);
	symbol_addr = 0;
	symname      = strtab + symtab[symtab_index].st_name;
		
	if (symtab_index) {
		symbol_addr = (unsigned long) _dl_find_hash(symname, scope, NULL, copyrel);
		if (!symbol_addr) goof++;
	}
	if (!goof) {
#if defined (__SUPPORT_LD_DEBUG__)
	        if(_dl_debug_move)
		  _dl_dprintf(_dl_debug_file,"\n%s move %x bytes from %x to %x",
			     symname, symtab[symtab_index].st_size,
			     symbol_addr, symtab[symtab_index].st_value);
#endif
			_dl_memcpy((char *) reloc_addr,
					(char *) (symbol_addr + (unsigned long)rpnt->r_addend), symtab[symtab_index].st_size);
	}

	return goof;
}

void _dl_parse_lazy_relocation_information(struct elf_resolve *tpnt, 
	unsigned long rel_addr, unsigned long rel_size, int type)
{
	(void) type;
	(void)_dl_parse(tpnt, NULL, rel_addr, rel_size, _dl_do_lazy_reloc);
}

int _dl_parse_relocation_information(struct elf_resolve *tpnt, 
	unsigned long rel_addr, unsigned long rel_size, int type)
{
	(void) type;
	return _dl_parse(tpnt, tpnt->symbol_scope, rel_addr, rel_size, _dl_do_reloc);
}

int _dl_parse_copy_information(struct dyn_elf *xpnt, unsigned long rel_addr, 
	unsigned long rel_size, int type)
{
	(void) type;
	return _dl_parse(xpnt->dyn, xpnt->next, rel_addr, rel_size, _dl_do_copy);
}