From d7d5c2634299d7cfd1df47ca6ed97ca77ee7a8b3 Mon Sep 17 00:00:00 2001
From: jdh8d <jdh8d@git.zephyr-software.com>
Date: Fri, 7 Apr 2017 14:24:41 +0000
Subject: [PATCH] Working version of eh-frame rewriting for non-pie
executables.
---
include/ehwrite.h | 5 +-
src/ehwrite.cpp | 128 ++++++++++++++++++++++++++++++++++------------
src/elfwrite.cpp | 4 +-
src/zipr.cpp | 11 ++--
4 files changed, 107 insertions(+), 41 deletions(-)
diff --git a/include/ehwrite.h b/include/ehwrite.h
index 357b288ba..a5f93b743 100644
--- a/include/ehwrite.h
+++ b/include/ehwrite.h
@@ -77,11 +77,12 @@ class EhWriterImpl_t : public EhWriter_t
libIRDB::Instruction_t* cs_insn_end;
libIRDB::Instruction_t* landing_pad;
int action_table_index;
- std::set<libIRDB::Relocation_t*> actions;
+ libIRDB::TTOrderVector_t actions;
};
std::vector<call_site_t> callsite_table;
- std::vector<std::set<libIRDB::Relocation_t*> > action_table;
+ std::vector<libIRDB::TTOrderVector_t> action_table;
std::vector<libIRDB::Relocation_t*> type_table;
+ uint64_t tt_encoding;
};
diff --git a/src/ehwrite.cpp b/src/ehwrite.cpp
index b7f01d08a..942fb19e1 100644
--- a/src/ehwrite.cpp
+++ b/src/ehwrite.cpp
@@ -218,7 +218,11 @@ bool EhWriterImpl_t<ptrsize>::EhProgramListingManip_t::isAdvanceDirective(const
template <int ptrsize>
EhWriterImpl_t<ptrsize>::FDErepresentation_t::LSDArepresentation_t::LSDArepresentation_t(Instruction_t* insn)
+ // if there are call sites, use the call site encoding. if not, set to omit for initializer.
+ // extend/canExtend should be able to extend an omit to a non-omit.
+ : tt_encoding( insn->GetEhCallSite() ? insn->GetEhCallSite()->GetTTEncoding() : 0xff)
{
+
extend(insn);
}
@@ -226,6 +230,10 @@ EhWriterImpl_t<ptrsize>::FDErepresentation_t::LSDArepresentation_t::LSDArepresen
static const auto RelocsEqual=[](const Relocation_t* a, const Relocation_t* b) -> bool
{
+ if(a==NULL && b==NULL)
+ return true;
+ if(a==NULL || b==NULL)
+ return false;
return
forward_as_tuple(a->GetType(), a->GetOffset(), a->GetWRT(), a->GetAddend()) ==
forward_as_tuple(b->GetType(), b->GetOffset(), b->GetWRT(), b->GetAddend());
@@ -237,16 +245,20 @@ bool EhWriterImpl_t<ptrsize>::FDErepresentation_t::LSDArepresentation_t::canExte
if(insn->GetEhCallSite() == NULL)
return true;
- const auto tt_encoding = insn->GetEhCallSite()->GetTTEncoding();
+ const auto insn_tt_encoding = insn->GetEhCallSite()->GetTTEncoding();
+
// no type table
- if(tt_encoding==0xff) // DW_EH_PE_omit
+ if(tt_encoding==0xff || insn_tt_encoding==0xff) // DW_EH_PE_omit (0xff)
{
- // but there's relocs for the type table,
- // this is a conflict.
- if(insn->GetEhCallSite()->GetRelocations().size() > 0 )
- return false;
+ // no encoding issues.
}
- assert(tt_encoding==0x3 || tt_encoding==0xff); // DW_EH_PE_udata4 or omit
+ // check if tt encodings match.
+ else if(insn_tt_encoding!=tt_encoding)
+ return true;
+
+ assert((tt_encoding&0xf)==0x3 || // encoding contains DW_EH_PE_udata4
+ (tt_encoding)==0xff || // or is exactly DW_EH_PE_omit
+ (tt_encoding&0xf)==0xb ); // or encoding contains DW_EH_PE_sdata4
const auto tt_entry_size=4;
const auto mismatch_tt_entry = find_if(
@@ -257,7 +269,11 @@ bool EhWriterImpl_t<ptrsize>::FDErepresentation_t::LSDArepresentation_t::canExte
const auto tt_index=candidate_reloc->GetOffset()/tt_entry_size;
if(tt_index>=type_table.size())
return false;
- return !RelocsEqual(candidate_reloc, type_table.at(tt_index));
+ const auto &tt_entry=type_table.at(tt_index);
+
+ if(tt_entry==NULL) // entry is empty, so no conflict
+ return false;
+ return !RelocsEqual(candidate_reloc, tt_entry);
}
);
@@ -272,6 +288,8 @@ void EhWriterImpl_t<ptrsize>::FDErepresentation_t::LSDArepresentation_t::extend(
if(insn->GetEhCallSite() == NULL)
return;
+ const auto insn_tt_encoding = insn->GetEhCallSite()->GetTTEncoding();
+
// FIXME: optimization possibilty: see if the last call site in the table
// has the same set of catch-types + landing_pad and is "close enough" to this insn.
// if so, combine.
@@ -285,6 +303,24 @@ void EhWriterImpl_t<ptrsize>::FDErepresentation_t::LSDArepresentation_t::extend(
cs.cs_insn_end=insn;
cs.landing_pad=insn->GetEhCallSite()->GetLandingPad();
+ if(tt_encoding == 0xff /* omit */)
+ {
+ /* existing is omit, use new encoding */
+ tt_encoding=insn_tt_encoding;
+ }
+ else if(insn_tt_encoding == 0xff /* omit */)
+ {
+ /* new encoding is omit, use current tt encoding */
+ }
+ else if(tt_encoding == insn_tt_encoding)
+ {
+ /* encodings match, -- do nothing */
+ }
+ else
+ assert(0); // canExtend failure?
+
+
+
// go through the relocations on the eh call site and
// resolve each one by putting it into a set.
@@ -303,13 +339,13 @@ void EhWriterImpl_t<ptrsize>::FDErepresentation_t::LSDArepresentation_t::extend(
// for now, this is the only supported reloc type on a EhCallSite
assert(reloc->GetType()=="type_table_entry");
- cs.actions.insert(reloc);
auto tt_it=find_if(type_table.begin(),type_table.end(),
- [reloc](const Relocation_t* candidate) { return RelocsEqual(candidate,reloc); });
+ [reloc](const Relocation_t* candidate) { return candidate!=NULL && RelocsEqual(candidate,reloc); });
if(tt_it==type_table.end())
{
const auto tt_encoding = insn->GetEhCallSite()->GetTTEncoding();
- assert(tt_encoding==0x3); // DW_EH_PE_udata4
+ assert((tt_encoding&0xf)==0x3 || // encoding contains DW_EH_PE_udata4
+ (tt_encoding&0xf)==0xb); // encoding contains DW_EH_PE_sdata4
const auto tt_entry_size=4;
const auto tt_index= reloc->GetOffset()/tt_entry_size;
if(tt_index>=type_table.size())
@@ -319,14 +355,8 @@ void EhWriterImpl_t<ptrsize>::FDErepresentation_t::LSDArepresentation_t::extend(
}
}
- // if the instruction has a cleanup, and there are other entries in the action table
- // add a NULL to the action table to indicate we need to insert a cleanup indicator.
- // if the cs.actions.size()==0, then we won't need any action list, and we can just set the "pointer"
- // to the action table entry to be "NULL"
- if(insn->GetEhCallSite()->GetHasCleanup() && cs.actions.size()>0)
- cs.actions.insert(NULL);
+ cs.actions=insn->GetEhCallSite()->GetTTOrderVector();
- // non-duplciating insert into the action table
auto at_it=find(action_table.begin(),action_table.end(), cs.actions);
if(at_it==action_table.end())
{
@@ -541,7 +571,25 @@ void EhWriterImpl_t<ptrsize>::GenerateEhOutput()
const auto landing_pad_base=calc_landing_pad_base();
// how to output actions
- const auto output_action=[&](const set<Relocation_t*> action_reloc_set, const uint32_t act_num) -> void
+ const auto output_action=[&](const libIRDB::TTOrderVector_t &act, const uint32_t act_num) -> void
+ {
+ const auto &ttov=act;
+ const auto biggest_ttov_index=ttov.size()-1;
+ auto act_entry_num=biggest_ttov_index;
+
+ for(int i=act_entry_num; i>=0; i--)
+ {
+ out<<"LSDA"<<dec<<lsda_num<<"_act"<<act_num<<"_start_entry"<<act_entry_num<<""<<":"<<endl;
+ out<<" .uleb128 "<<dec<<ttov.at(act_entry_num)<<endl;
+ if(act_entry_num==biggest_ttov_index)
+ out<<" .uleb128 0 "<<endl;
+ else
+ out<<" .uleb128 LSDA"<<lsda_num<<"_act"<<act_num<<"_start_entry"<<act_entry_num+1<<" - . "<<endl;
+ act_entry_num--;
+ }
+ };
+
+#if 0
{
// determine if cleanup is requested.
const auto cleanup_it=find(action_reloc_set.begin(), action_reloc_set.end(), (Relocation_t*)NULL);
@@ -578,7 +626,7 @@ void EhWriterImpl_t<ptrsize>::GenerateEhOutput()
{
const auto catch_all_reloc=*catch_all_it;
const auto tt_it=find_if(lsda->type_table.begin(), lsda->type_table.end(),
- [&](const Relocation_t* candidate) { return RelocsEqual(candidate, catch_all_reloc); });
+ [&](const Relocation_t* candidate) { return candidate && RelocsEqual(candidate, catch_all_reloc); });
assert(tt_it != lsda->type_table.end());
const auto tt_index=tt_it-lsda->type_table.begin();
@@ -607,7 +655,7 @@ void EhWriterImpl_t<ptrsize>::GenerateEhOutput()
}
const auto tt_it=find_if(lsda->type_table.begin(), lsda->type_table.end(),
- [action_reloc](const Relocation_t* candidate) { return RelocsEqual(action_reloc,candidate); } );
+ [action_reloc](const Relocation_t* candidate) { return candidate!=NULL && RelocsEqual(action_reloc,candidate); } );
assert(tt_it != lsda->type_table.end());
const auto tt_index=tt_it-lsda->type_table.begin();
out<<"LSDA"<<dec<<lsda_num<<"_act"<<act_num<<"_start_entry"<<act_entry_num<<""<<":"<<endl;
@@ -620,6 +668,7 @@ void EhWriterImpl_t<ptrsize>::GenerateEhOutput()
}
//out<<" .equ LSDA"<<lsda_num<<"_act"<<act_num<<"_start, LSDA"<<lsda_num<<"_act"<<act_num<<"_start_entry0"<<endl;
};
+#endif
const auto output_callsite=[&](const typename FDErepresentation_t::LSDArepresentation_t::call_site_t &cs, const uint32_t cs_num) -> void
@@ -658,7 +707,7 @@ void EhWriterImpl_t<ptrsize>::GenerateEhOutput()
};
- const auto output_header=[&]()
+ const auto output_lsda_header=[&]()
{
if(landing_pad_base==fde->start_addr)
{
@@ -678,18 +727,25 @@ void EhWriterImpl_t<ptrsize>::GenerateEhOutput()
}
out<<""<<endl;
out<<" # 3) encoding of type table entries"<<endl;
- out<<" .byte 0x3 # DW_EH_PE_udata4"<<endl;
+ out<<" .byte 0x"<<hex<<lsda->tt_encoding<<" # DW_EH_PE_udata4"<<endl;
out<<""<<endl;
out<<" # 4) type table pointer -- always a uleb128"<<endl;
- out<<" .uleb128 LSDA"<<lsda_num<<"_type_table_end - LSDA"<<lsda_num<<"_tt_ptr_end"<<endl;
- out<<"LSDA"<<lsda_num<<"_tt_ptr_end:"<<endl;
+ if(lsda->tt_encoding==0xff) /* omit */
+ {
+ out<<" # .uleb128 LSDAptr omitted"<< endl;
+ }
+ else
+ {
+ out<<" .uleb128 LSDA"<<dec<<lsda_num<<"_type_table_end - LSDA"<<lsda_num<<"_tt_ptr_end"<<endl;
+ }
+ out<<"LSDA"<<dec<<lsda_num<<"_tt_ptr_end:"<<endl;
out<<""<<endl;
out<<" # 5) call site table encoding"<<endl;
out<<" .byte 0x1 # DW_EH_PE_uleb128 "<<endl;
out<<""<<endl;
out<<" # 6) the length of the call site table"<<endl;
- out<<" .uleb128 LSDA"<<lsda_num<<"_cs_tab_end-LSDA"<<lsda_num<<"_cs_tab_start"<<endl;
- out<<"LSDA"<<lsda_num<<"_cs_tab_start:"<<endl;
+ out<<" .uleb128 LSDA"<<dec<<lsda_num<<"_cs_tab_end-LSDA"<<dec<<lsda_num<<"_cs_tab_start"<<endl;
+ out<<"LSDA"<<dec<<lsda_num<<"_cs_tab_start:"<<endl;
};
const auto output_call_site_table=[&]()
@@ -719,10 +775,15 @@ void EhWriterImpl_t<ptrsize>::GenerateEhOutput()
out<<"LSDA"<<dec<<lsda_num<<"_type_table_start:"<<endl;
for_each( lsda->type_table.rbegin(), lsda->type_table.rend(), [&](const Relocation_t* reloc)
{
- if(reloc->GetWRT()==NULL)
+ if(reloc==NULL)
+ {
+ // indicates a catch all or empty type table entry
+ out<<" .int 0x0 # not used!"<<endl;
+ }
+ else if(reloc->GetWRT()==NULL)
{
- // indicates a catch all
- out<<" .int 0x0"<<endl;
+ // indicates a catch all or empty type table entry
+ out<<" .int 0x0 # catch all "<<endl;
}
else
{
@@ -730,14 +791,17 @@ void EhWriterImpl_t<ptrsize>::GenerateEhOutput()
const auto scoop=dynamic_cast<DataScoop_t*>(reloc->GetWRT());
assert(scoop);
const auto final_addr=scoop->GetStart()->GetVirtualOffset() + reloc->GetAddend();
- out<<" .int 0x"<<hex<<final_addr<<endl;
+ if(((lsda->tt_encoding)&0x10) == 0x10) // if encoding contains pcrel (0x10).
+ out<<" .int 0x"<<hex<<final_addr<<" - . "<<endl;
+ else
+ out<<" .int 0x"<<hex<<final_addr<<endl;
}
});
out<<"LSDA"<<dec<<lsda_num<<"_type_table_end:"<<endl;
};
- output_header();
+ output_lsda_header();
output_call_site_table();
output_action_table();
output_type_table();
diff --git a/src/elfwrite.cpp b/src/elfwrite.cpp
index 9eb41bad3..22a3ce7ac 100644
--- a/src/elfwrite.cpp
+++ b/src/elfwrite.cpp
@@ -717,7 +717,7 @@ void ElfWriterImpl<T_Elf_Ehdr,T_Elf_Phdr,T_Elf_Addr,T_Elf_Shdr,T_Elf_Sym, T_Elf_
const PageData_t &page=pagemap[new_phdrs[i].p_vaddr+j];
// is it the last page?
- if(j+PAGE_SIZE < new_phdrs[i].p_filesz)
+ if(j+PAGE_SIZE < new_phdrs[i].p_filesz || m_write_sections )
{
fwrite(page.data.data(), PAGE_SIZE, 1, fout);
}
@@ -781,8 +781,6 @@ void ElfWriterImpl<T_Elf_Ehdr,T_Elf_Phdr,T_Elf_Addr,T_Elf_Shdr,T_Elf_Sym, T_Elf_
{
fseek(fout,0,SEEK_END);
long cur_file_pos=ftell(fout);
- fseek(fout,cur_file_pos+1,SEEK_SET);
- cur_file_pos=ftell(fout);
StringTable_t strtab;
diff --git a/src/zipr.cpp b/src/zipr.cpp
index 041e99de3..b1635e2ce 100644
--- a/src/zipr.cpp
+++ b/src/zipr.cpp
@@ -2229,7 +2229,7 @@ void ZiprImpl_t::PlaceDollops()
}
if (!placed) {
- cout << "Using default place locator." << endl;
+ // cout << "Using default place locator." << endl;
/*
* TODO: Re-enable this ONCE we figure out why the dollop
* sizes are not being recalculated correctly.
@@ -2351,7 +2351,7 @@ void ZiprImpl_t::PlaceDollops()
to_place->Place(cur_addr);
- cout << "to_place->GetSize(): " << to_place->GetSize() << endl;
+ // cout << "to_place->GetSize(): " << to_place->GetSize() << endl;
fits_entirely = (to_place->GetSize() <= (placement.GetEnd()-cur_addr));
all_fallthroughs_fit = (wcds <= (placement.GetEnd()-cur_addr));
@@ -3220,8 +3220,11 @@ RangeAddress_t ZiprImpl_t::PlopDollopEntry(
abs_displacement = *displacement;
*displacement = abs_displacement - addr;
- cout<<"absolute displacement: "<< hex << abs_displacement<<endl;
- cout<<"relative displacement: "<< hex << *displacement<<endl;
+ if(m_verbose)
+ {
+ cout<<"absolute displacement: "<< hex << abs_displacement<<endl;
+ cout<<"relative displacement: "<< hex << *displacement<<endl;
+ }
/*
* Update the instruction with the relative displacement.
--
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