ppsspp/Core/ELF/ElfReader.cpp
2013-08-25 19:43:18 +02:00

586 lines
14 KiB
C++

// Copyright (c) 2012- PPSSPP Project.
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, version 2.0 or later versions.
// This program 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 General Public License 2.0 for more details.
// A copy of the GPL 2.0 should have been included with the program.
// If not, see http://www.gnu.org/licenses/
// Official git repository and contact information can be found at
// https://github.com/hrydgard/ppsspp and http://www.ppsspp.org/.
#include "Core/MemMap.h"
#include "Core/Reporting.h"
#include "../MIPS/MIPSTables.h"
#include "ElfReader.h"
#include "../Debugger/SymbolMap.h"
#include "../HLE/sceKernelMemory.h"
const char *ElfReader::GetSectionName(int section)
{
if (sections[section].sh_type == SHT_NULL)
return 0;
int nameOffset = sections[section].sh_name;
char *ptr = (char*)GetSectionDataPtr(header->e_shstrndx);
if (ptr)
return ptr + nameOffset;
else
return 0;
}
void addrToHiLo(u32 addr, u16 &hi, s16 &lo)
{
lo = (addr & 0xFFFF);
u32 naddr = addr - lo;
hi = naddr>>16;
u32 test = (hi<<16) + lo;
if (test != addr)
{
WARN_LOG_REPORT(LOADER, "HI16/LO16 relocation failure?");
}
}
void ElfReader::LoadRelocations(Elf32_Rel *rels, int numRelocs)
{
for (int r = 0; r < numRelocs; r++)
{
u32 info = rels[r].r_info;
u32 addr = rels[r].r_offset;
int type = info & 0xf;
int readwrite = (info>>8) & 0xff;
int relative = (info>>16) & 0xff;
//0 = code
//1 = data
addr += segmentVAddr[readwrite];
u32 op = Memory::Read_Instruction(addr).encoding;
const bool log = false;
//log=true;
if (log)
{
DEBUG_LOG(LOADER,"rel at: %08x type: %08x",addr,info);
}
u32 relocateTo = segmentVAddr[relative];
switch (type)
{
case R_MIPS_32:
if (log)
DEBUG_LOG(LOADER,"Full address reloc %08x", addr);
//full address, no problemo
op += relocateTo;
break;
case R_MIPS_26: //j, jal
//add on to put in correct address space
if (log)
DEBUG_LOG(LOADER,"j/jal reloc %08x", addr);
op = (op & 0xFC000000) | (((op&0x03FFFFFF)+(relocateTo>>2))&0x03FFFFFF);
break;
case R_MIPS_HI16: //lui part of lui-addiu pairs
{
if (log)
DEBUG_LOG(LOADER,"HI reloc %08x", addr);
u32 cur = (op & 0xFFFF) << 16;
u16 hi = 0;
bool found = false;
for (int t = r + 1; t<numRelocs; t++)
{
if ((rels[t].r_info & 0xF) == R_MIPS_LO16)
{
u32 corrLoAddr = rels[t].r_offset + segmentVAddr[readwrite];
if (log)
{
DEBUG_LOG(LOADER,"Corresponding lo found at %08x", corrLoAddr);
}
s16 lo = (s32)(s16)(u16)(Memory::ReadUnchecked_U32(corrLoAddr) & 0xFFFF); //signed??
cur += lo;
cur += relocateTo;
addrToHiLo(cur, hi, lo);
found = true;
break;
}
}
if (!found)
ERROR_LOG_REPORT(LOADER, "R_MIPS_HI16: could not find R_MIPS_LO16");
op = (op & 0xFFFF0000) | (hi);
}
break;
case R_MIPS_LO16: //addiu part of lui-addiu pairs
{
if (log)
DEBUG_LOG(LOADER,"LO reloc %08x", addr);
u32 cur = op & 0xFFFF;
cur += relocateTo;
cur &= 0xFFFF;
op = (op & 0xFFFF0000) | cur;
}
break;
case R_MIPS_GPREL16: //gp
// It seems safe to ignore this, almost a notification of a gp-relative operation?
break;
case R_MIPS_16:
{
char temp[256];
MIPSDisAsm(MIPSOpcode(op), 0, temp);
ERROR_LOG_REPORT(LOADER, "WARNING: Unsupported R_MIPS_16 reloc @ %08x : %s", addr, temp);
}
break;
case R_MIPS_NONE:
// This shouldn't matter, not sure the purpose of it.
break;
default:
{
char temp[256];
MIPSDisAsm(MIPSOpcode(op), 0, temp);
ERROR_LOG_REPORT(LOADER,"ARGH IT'S AN UNKNOWN RELOCATION!!!!!!!! %08x, type=%d : %s", addr, type, temp);
}
break;
}
Memory::Write_U32(op, addr);
}
}
void ElfReader::LoadRelocations2(int rel_seg)
{
Elf32_Phdr *ph;
u8 *buf, *end, *flag_table, *type_table;
int flag_table_size, type_table_size;
int flag_bits, seg_bits, type_bits;
int cmd, flag, seg, type;
int off_seg = 0, addr_seg, rel_base, rel_offset;
int relocate_to, last_type, lo16 = 0;
u32 op, addr;
int rcount = 0;
ph = segments + rel_seg;
buf = (u8*)GetSegmentPtr(rel_seg);
end = buf+ph->p_filesz;
flag_bits = buf[2];
type_bits = buf[3];
seg_bits = 1;
while((1<<seg_bits)<rel_seg)
seg_bits += 1;
buf += 4;
flag_table = buf;
flag_table_size = flag_table[0];
buf += flag_table_size;
type_table = buf;
type_table_size = type_table[0];
buf += type_table_size;
rel_base = 0;
last_type = -1;
while(buf<end){
cmd = *(u16*)(buf);
buf += 2;
flag = ( cmd<<(16-flag_bits))&0xffff;
flag = (flag>>(16-flag_bits))&0xffff;
flag = flag_table[flag];
seg = (cmd<<(16-seg_bits-flag_bits))&0xffff;
seg = (seg>>(16-seg_bits))&0xffff;
type = ( cmd<<(16-type_bits-seg_bits-flag_bits))&0xffff;
type = (type>>(16-type_bits))&0xffff;
type = type_table[type];
if((flag&0x01)==0){
off_seg = seg;
if((flag&0x06)==0){
rel_base = cmd>>(seg_bits+flag_bits);
}else if((flag&0x06)==4){
rel_base = buf[0] | (buf[1]<<8) | (buf[2]<<16) | (buf[3]<<24);
buf += 4;
}else{
ERROR_LOG_REPORT(LOADER, "Rel2: invalid size flag! %x", flag);
rel_base = 0;
}
}else{
addr_seg = seg;
relocate_to = segmentVAddr[addr_seg];
if((flag&0x06)==0x00){
rel_offset = cmd;
if(cmd&0x8000){
rel_offset |= 0xffff0000;
rel_offset >>= type_bits+seg_bits+flag_bits;
rel_offset |= 0xffff0000;
}else{
rel_offset >>= type_bits+seg_bits+flag_bits;
}
rel_base += rel_offset;
}else if((flag&0x06)==0x02){
rel_offset = cmd;
if(cmd&0x8000)
rel_offset |= 0xffff0000;
rel_offset >>= type_bits+seg_bits+flag_bits;
rel_offset = (rel_offset<<16) | (buf[0]) | (buf[1]<<8);
buf += 2;
rel_base += rel_offset;
}else if((flag&0x06)==0x04){
rel_base = buf[0] | (buf[1]<<8) | (buf[2]<<16) | (buf[3]<<24);
buf += 4;
}else{
ERROR_LOG_REPORT(LOADER, "Rel2: invalid relocat size flag! %x", flag);
}
rel_offset = rel_base+segmentVAddr[off_seg];
if((flag&0x38)==0x00){
lo16 = 0;
}else if((flag&0x38)==0x08){
if(last_type!=0x04)
lo16 = 0;
}else if((flag&0x38)==0x10){
lo16 = (buf[0]) | (buf[1]<<8);
if(lo16&0x8000)
lo16 |= 0xffff0000;
buf += 2;
}else{
ERROR_LOG_REPORT(LOADER, "Rel2: invalid lo16 type! %x", flag);
}
op = Memory::ReadUnchecked_U32(rel_offset);
DEBUG_LOG(LOADER, "Rel2: %5d: CMD=0x%04X type=%d off_seg=%d offset=%08x addr_seg=%d op=%08x\n", rcount, cmd, type, off_seg, rel_base, addr_seg, op);
switch(type){
case 0:
continue;
case 2: // R_MIPS_32
op += relocate_to;
break;
case 3: // R_MIPS_26
case 6: // R_MIPS_J26
case 7: // R_MIPS_JAL26
op = (op&0xFC000000) | (((op&0x03FFFFFF)+(relocate_to>>2))&0x03FFFFFF);
break;
case 4: // R_MIPS_HI16
addr = ((op<<16)+lo16)+relocate_to;
if(addr&0x8000)
addr += 0x00010000;
op = (op&0xffff0000) | (addr>>16 );
break;
case 1:
case 5: // R_MIPS_LO16
op = (op&0xffff0000) | (((op&0xffff)+relocate_to)&0xffff);
break;
default:
break;
}
Memory::Write_U32(op, rel_offset);
rcount += 1;
}
}
}
bool ElfReader::LoadInto(u32 loadAddress)
{
DEBUG_LOG(LOADER,"String section: %i", header->e_shstrndx);
//TODO - Check header->e_ident here
//let's dump string section
/*
char *ptr = (char*)GetSectionDataPtr(header->e_shstrndx);
if (*ptr == 0)
ptr++;
ptr+=513;
while (*ptr != 0)
{
int len = strlen(ptr);
LOG(LOADER,"XX %s",ptr);
ptr+=len;
ptr++;
}*/
sectionOffsets = new u32[GetNumSections()];
sectionAddrs = new u32[GetNumSections()];
// Should we relocate?
bRelocate = (header->e_type != ET_EXEC);
entryPoint = header->e_entry;
u32 totalStart = 0xFFFFFFFF;
u32 totalEnd = 0;
for (int i = 0; i < header->e_phnum; i++) {
Elf32_Phdr *p = &segments[i];
if (p->p_type == PT_LOAD) {
if (p->p_vaddr < totalStart)
totalStart = p->p_vaddr;
if (p->p_vaddr + p->p_memsz > totalEnd)
totalEnd = p->p_vaddr + p->p_memsz;
}
}
totalSize = totalEnd - totalStart;
if (!bRelocate)
{
// Binary is prerelocated, load it where the first segment starts
vaddr = userMemory.AllocAt(totalStart, totalSize, "ELF");
}
else if (loadAddress)
{
// Binary needs to be relocated: add loadAddress to the binary start address
vaddr = userMemory.AllocAt(loadAddress + totalStart, totalSize, "ELF");
}
else
{
// Just put it where there is room
vaddr = userMemory.Alloc(totalSize, false, "ELF");
}
if (vaddr == (u32)-1) {
ERROR_LOG_REPORT(LOADER, "Failed to allocate memory for ELF!");
return false;
}
if (bRelocate) {
DEBUG_LOG(LOADER,"Relocatable module");
entryPoint += vaddr;
} else {
DEBUG_LOG(LOADER,"Prerelocated executable");
}
DEBUG_LOG(LOADER,"%i segments:", header->e_phnum);
// First pass : Get the damn bits into RAM
u32 baseAddress = bRelocate?vaddr:0;
for (int i=0; i<header->e_phnum; i++)
{
Elf32_Phdr *p = segments + i;
DEBUG_LOG(LOADER, "Type: %08x Vaddr: %08x Filesz: %08x Memsz: %08x ", (int)p->p_type, (u32)p->p_vaddr, (int)p->p_filesz, (int)p->p_memsz);
if (p->p_type == PT_LOAD)
{
segmentVAddr[i] = baseAddress + p->p_vaddr;
u32 writeAddr = segmentVAddr[i];
u8 *src = GetSegmentPtr(i);
u8 *dst = Memory::GetPointer(writeAddr);
u32 srcSize = p->p_filesz;
u32 dstSize = p->p_memsz;
if (srcSize < dstSize)
{
memset(dst + srcSize, 0, dstSize - srcSize); //zero out bss
}
memcpy(dst, src, srcSize);
DEBUG_LOG(LOADER,"Loadable Segment Copied to %08x, size %08x", writeAddr, (u32)p->p_memsz);
}
}
userMemory.ListBlocks();
DEBUG_LOG(LOADER,"%i sections:", header->e_shnum);
for (int i = 0; i < GetNumSections(); i++)
{
Elf32_Shdr *s = &sections[i];
const char *name = GetSectionName(i);
u32 writeAddr = s->sh_addr + baseAddress;
sectionOffsets[i] = writeAddr - vaddr;
sectionAddrs[i] = writeAddr;
if (s->sh_flags & SHF_ALLOC)
{
DEBUG_LOG(LOADER,"Data Section found: %s Sitting at %08x, size %08x", name, writeAddr, (u32)s->sh_size);
}
else
{
DEBUG_LOG(LOADER,"NonData Section found: %s Ignoring (size=%08x) (flags=%08x)", name, (u32)s->sh_size, (u32)s->sh_flags);
}
}
DEBUG_LOG(LOADER,"Relocations:");
// Second pass: Do necessary relocations
for (int i=0; i<GetNumSections(); i++)
{
Elf32_Shdr *s = &sections[i];
const char *name = GetSectionName(i);
if (s->sh_type == SHT_PSPREL)
{
//We have a relocation table!
int sectionToModify = s->sh_info;
if (sectionToModify >= 0)
{
if (!(sections[sectionToModify].sh_flags & SHF_ALLOC))
{
ERROR_LOG_REPORT(LOADER, "Trying to relocate non-loaded section %s", GetSectionName(sectionToModify));
continue;
}
int numRelocs = s->sh_size / sizeof(Elf32_Rel);
Elf32_Rel *rels = (Elf32_Rel *)GetSectionDataPtr(i);
DEBUG_LOG(LOADER,"%s: Performing %i relocations on %s",name,numRelocs,GetSectionName(sectionToModify));
LoadRelocations(rels, numRelocs);
}
else
{
WARN_LOG_REPORT(LOADER, "sectionToModify = %i - ignoring PSP relocation sector %i", sectionToModify, i);
}
}
else if (s->sh_type == SHT_REL)
{
DEBUG_LOG(LOADER, "Traditional relocation section found.");
if (!bRelocate)
{
DEBUG_LOG(LOADER, "Binary is prerelocated. Skipping relocations.");
}
else
{
//We have a relocation table!
int sectionToModify = s->sh_info;
if (sectionToModify >= 0)
{
if (!(sections[sectionToModify].sh_flags & SHF_ALLOC))
{
ERROR_LOG_REPORT(LOADER, "Trying to relocate non-loaded section %s, ignoring", GetSectionName(sectionToModify));
continue;
}
}
else
{
WARN_LOG_REPORT(LOADER, "sectionToModify = %i - ignoring relocation sector %i", sectionToModify, i);
}
ERROR_LOG_REPORT(LOADER, "Traditional relocations unsupported.");
}
}
}
// Segment relocations (a few games use them)
if (GetNumSections() == 0)
{
for (int i=0; i<header->e_phnum; i++)
{
Elf32_Phdr *p = &segments[i];
if (p->p_type == 0x700000A0)
{
INFO_LOG(LOADER,"Loading segment relocations");
int numRelocs = p->p_filesz / sizeof(Elf32_Rel);
Elf32_Rel *rels = (Elf32_Rel *)GetSegmentPtr(i);
LoadRelocations(rels, numRelocs);
} else if (p->p_type == 0x700000A1)
{
INFO_LOG(LOADER,"Loading segment relocations2");
LoadRelocations2(i);
}
}
}
NOTICE_LOG(LOADER,"ELF loading completed successfully.");
return true;
}
SectionID ElfReader::GetSectionByName(const char *name, int firstSection)
{
for (int i = firstSection; i < header->e_shnum; i++)
{
const char *secname = GetSectionName(i);
if (secname != 0 && strcmp(name, secname) == 0)
{
return i;
}
}
return -1;
}
bool ElfReader::LoadSymbols()
{
bool hasSymbols = false;
SectionID sec = GetSectionByName(".symtab");
if (sec != -1)
{
int stringSection = sections[sec].sh_link;
const char *stringBase = (const char*)GetSectionDataPtr(stringSection);
//We have a symbol table!
Elf32_Sym *symtab = (Elf32_Sym *)(GetSectionDataPtr(sec));
int numSymbols = sections[sec].sh_size / sizeof(Elf32_Sym);
for (int sym = 0; sym<numSymbols; sym++)
{
int size = symtab[sym].st_size;
if (size == 0)
continue;
int bind = symtab[sym].st_info >> 4;
int type = symtab[sym].st_info & 0xF;
int sectionIndex = symtab[sym].st_shndx;
int value = symtab[sym].st_value;
const char *name = stringBase + symtab[sym].st_name;
if (bRelocate)
value += sectionAddrs[sectionIndex];
SymbolType symtype = ST_DATA;
switch (type)
{
case STT_OBJECT:
symtype = ST_DATA; break;
case STT_FUNC:
symtype = ST_FUNCTION; break;
default:
continue;
}
symbolMap.AddSymbol(name, value, size, symtype);
hasSymbols = true;
//...
}
}
return hasSymbols;
}