From 17c2172cfd219215d2fbd0b990c58cf57beed06a Mon Sep 17 00:00:00 2001
From: jdh8d <jdh8d@git.zephyr-software.com>
Date: Fri, 15 Sep 2017 15:44:41 +0000
Subject: [PATCH] Added emt support for prefork+bilr+p1 (sketchy still), K6+NOG
(seems stable with all xforms enabled). I also did some peasoup/cfar fixes
to support determunistic ID assignment for IRDB objects -- this was needed
for marshaling because the EMT plugin uses ID matching to find identical
objects (stack, scoop, instruction, etc.) Next, I fixed bugs in p1transform
where the p1.map wasn't getting proper IDs. Lastly, I added an option to
zipr/elfwrite to disable bss-optimization, this was necessary for marshaling
as that bss segments stay named/mapped to the binary and cannot be combined
with other segments.
---
include/elfwrite.h | 17 ++++++++++++++--
include/zipr_impl.h | 3 ++-
src/elfwrite.cpp | 49 +++++++++++++++++++++++++++++++++------------
src/zipr.cpp | 6 ++++--
4 files changed, 57 insertions(+), 18 deletions(-)
diff --git a/include/elfwrite.h b/include/elfwrite.h
index 0c412bb..eaa2bb9 100644
--- a/include/elfwrite.h
+++ b/include/elfwrite.h
@@ -70,6 +70,18 @@ class ElfWriter
public:
LoadSegment_t() :filesz(0), memsz(0), filepos(0), start_page(0), m_perms(0) { }
+ LoadSegment_t( unsigned int p_filesz, unsigned int p_memsz, unsigned int p_filepos, unsigned int p_start_page, unsigned int p_m_perms)
+ :
+ filesz(p_filesz),
+ memsz(p_memsz),
+ filepos(p_filepos),
+ start_page(p_start_page),
+ m_perms(p_m_perms)
+ {
+
+ }
+
+
unsigned int filesz;
unsigned int memsz;
unsigned int filepos;
@@ -82,7 +94,7 @@ class ElfWriter
typedef std::map<libIRDB::virtual_offset_t, PageData_t> PageMap_t;
public:
- ElfWriter(libIRDB::FileIR_t* firp, bool write_sections) : m_firp(firp), m_write_sections(write_sections) { }
+ ElfWriter(libIRDB::FileIR_t* firp, bool write_sections, bool bss_opts) : m_firp(firp), m_write_sections(write_sections), m_bss_opts(bss_opts) { }
virtual ~ElfWriter() {}
void Write(const ELFIO::elfio *elfiop, libIRDB::FileIR_t* firp, const std::string &out_file, const std::string &infile);
@@ -112,6 +124,7 @@ class ElfWriter
protected:
libIRDB::FileIR_t* m_firp;
bool m_write_sections;
+ bool m_bss_opts;
private:
libIRDB::virtual_offset_t DetectMinAddr(const ELFIO::elfio *elfiop, libIRDB::FileIR_t* firp, const std::string &out_file);
libIRDB::virtual_offset_t DetectMaxAddr(const ELFIO::elfio *elfiop, libIRDB::FileIR_t* firp, const std::string &out_file);
@@ -134,7 +147,7 @@ class ElfWriterImpl : public ElfWriter
{
public:
- ElfWriterImpl(libIRDB::FileIR_t* firp, bool write_sections) : ElfWriter(firp, write_sections) { }
+ ElfWriterImpl(libIRDB::FileIR_t* firp, bool write_sections, bool bss_opts ) : ElfWriter(firp, write_sections, bss_opts) { }
protected:
int GetFileHeaderSize() { return sizeof(T_Elf_Ehdr); }
diff --git a/include/zipr_impl.h b/include/zipr_impl.h
index f4a340d..44824fd 100644
--- a/include/zipr_impl.h
+++ b/include/zipr_impl.h
@@ -55,6 +55,7 @@ class ZiprImpl_t : public Zipr_t
m_verbose("verbose", true),
m_apply_nop("apply_nop", false),
m_add_sections("add-sections", false),
+ m_bss_opts("bss-opts", true),
m_variant("variant"),
m_architecture("architecture"),
m_seed("seed", 0),
@@ -490,7 +491,7 @@ class ZiprImpl_t : public Zipr_t
// Options
ZiprOptions_t m_zipr_options;
ZiprStringOption_t m_output_filename, m_callbacks, m_objcopy;
- ZiprBooleanOption_t m_replop, m_verbose, m_apply_nop, m_add_sections;
+ ZiprBooleanOption_t m_replop, m_verbose, m_apply_nop, m_add_sections, m_bss_opts;
ZiprIntegerOption_t m_variant, m_architecture, m_seed;
ZiprStringOption_t m_dollop_map_filename;
diff --git a/src/elfwrite.cpp b/src/elfwrite.cpp
index e65edb0..4b63029 100644
--- a/src/elfwrite.cpp
+++ b/src/elfwrite.cpp
@@ -156,34 +156,50 @@ void ElfWriter::SortSegmap()
void ElfWriter::CreateSegmap(const ELFIO::elfio *elfiop, FileIR_t* firp, const string &out_file)
{
+ const auto should_bss_optimize= [&] (const PageData_t& perms)
+ {
+ return (perms.is_zero_initialized() && m_bss_opts);
+ };
+
+
+
// init some segment vars.
- virtual_offset_t segstart=pagemap.begin()->first;
- PageData_t segperms=pagemap.begin()->second;
- virtual_offset_t segend=segstart+PAGE_SIZE;
- virtual_offset_t initend=segstart;
- if(pagemap.begin()->second.is_zero_initialized())
- initend=segstart;
- else
- initend=segend;
+ auto segstart=pagemap.begin()->first;
+ auto segperms=pagemap.begin()->second;
+ auto segend=segstart+PAGE_SIZE;
+ auto initend=segstart;
- PageMap_t::iterator it=pagemap.begin();
+ const auto update_initend=[&](const PageData_t& perms)
+ {
+ if(should_bss_optimize(perms))
+ initend=segstart;
+ else
+ initend=segend;
+ };
+
+ update_initend(segperms);
+
+ auto it=pagemap.begin();
++it; // handled first one above.
for( /* init'd above */; it!=pagemap.end(); ++it)
{
// grab page address and perms
- virtual_offset_t pagestart=it->first;
- const PageData_t &perms=it->second;
+ const auto pagestart=it->first;
+ const auto &perms=it->second;
// if we switch perms, or skip a page
if( (perms.m_perms!=segperms.m_perms) || (segend!=pagestart))
{
+/*
LoadSegment_t *seg=new LoadSegment_t;
seg->memsz=segend-segstart;
seg->filesz=initend-segstart;
seg->start_page=segstart;
seg->m_perms=segperms.m_perms;
+*/
+ const auto seg=new LoadSegment_t(initend-segstart, segend-segstart, 0, segstart,segperms.m_perms);
segvec.push_back(seg);
cout<<"Found segment "<<hex<<segstart<<"-"<<(segend-1)<<", perms="<<segperms.m_perms<<", memsz="<<seg->memsz<<", filesz="<<seg->filesz<<endl;
@@ -191,28 +207,35 @@ void ElfWriter::CreateSegmap(const ELFIO::elfio *elfiop, FileIR_t* firp, const s
segperms=perms;
segstart=pagestart;
segend=segstart+PAGE_SIZE;
- if(perms.is_zero_initialized())
+
+ update_initend(perms);
+/*
+ if( should_bss_optimize(perms) ) // perms.is_zero_initialized() && m_bss_opts)
initend=segstart;
else
initend=segend;
+*/
}
else
{
// else, same permission and next page, extend segment.
segend=pagestart+PAGE_SIZE;
- if(!perms.is_zero_initialized())
+ if(! should_bss_optimize(perms) ) // !perms.is_zero_initialized() || ! m_bss_opts)
initend=pagestart+PAGE_SIZE;
}
}
// make sure we print the last one
+/*
LoadSegment_t *seg=new LoadSegment_t;
seg->memsz=segend-segstart;
seg->filesz=initend-segstart;
seg->start_page=segstart;
seg->m_perms=segperms.m_perms;
+*/
+ const auto seg=new LoadSegment_t(initend-segstart, segend-segstart, 0, segstart,segperms.m_perms);
segvec.push_back(seg);
cout<<"Found segment "<<hex<<segstart<<"-"<<(segend-1)<<", perms="<<segperms.m_perms<<", memsz="<<seg->memsz<<", filesz="<<seg->filesz<<endl;
diff --git a/src/zipr.cpp b/src/zipr.cpp
index c71d9d1..addf5e7 100644
--- a/src/zipr.cpp
+++ b/src/zipr.cpp
@@ -156,6 +156,7 @@ ZiprOptionsNamespace_t *ZiprImpl_t::RegisterOptions(ZiprOptionsNamespace_t *glob
m_add_sections.SetDescription("Enable writing of section headers using elfwriter.");
+ m_bss_opts.SetDescription("Enable/Disable optimizing BSS segments so they aren't written to the binary.");
m_verbose.SetDescription("Enable verbose output");
m_apply_nop.SetDescription("Apply NOP to patches that fallthrough.");
m_variant.SetDescription("Variant ID.");
@@ -185,6 +186,7 @@ ZiprOptionsNamespace_t *ZiprImpl_t::RegisterOptions(ZiprOptionsNamespace_t *glob
global->AddOption(&m_verbose);
global->AddOption(&m_apply_nop);
global->AddOption(&m_add_sections);
+ global->AddOption(&m_bss_opts);
zipr_namespace->MergeNamespace(memory_space.RegisterOptions(global));
return zipr_namespace;
@@ -3729,11 +3731,11 @@ void ZiprImpl_t::OutputBinaryFile(const string &name)
ElfWriter *ew=NULL;
if(m_firp->GetArchitectureBitWidth()==64)
{
- ew=new ElfWriter64(m_firp, m_add_sections);
+ ew=new ElfWriter64(m_firp, m_add_sections, m_bss_opts);
}
else if(m_firp->GetArchitectureBitWidth()==32)
{
- ew=new ElfWriter32(m_firp, m_add_sections);
+ ew=new ElfWriter32(m_firp, m_add_sections, m_bss_opts);
}
else assert(0);
--
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