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Diffstat (limited to 'compiler/elf_builder.h')
-rw-r--r--compiler/elf_builder.h133
1 files changed, 99 insertions, 34 deletions
diff --git a/compiler/elf_builder.h b/compiler/elf_builder.h
index 124ed03c21..323c933ab1 100644
--- a/compiler/elf_builder.h
+++ b/compiler/elf_builder.h
@@ -584,11 +584,12 @@ class ElfBuilder FINAL {
// | Elf_Ehdr |
// +-------------------------+
// | Elf_Phdr PHDR |
- // | Elf_Phdr LOAD R | .dynsym .dynstr .hash .rodata
+ // | Elf_Phdr LOAD R | .dynsym .dynstr .hash .eh_frame .eh_frame_hdr .rodata
// | Elf_Phdr LOAD R X | .text
// | Elf_Phdr LOAD RW | .bss (Optional)
// | Elf_Phdr LOAD RW | .dynamic
// | Elf_Phdr DYNAMIC | .dynamic
+ // | Elf_Phdr EH_FRAME R | .eh_frame_hdr
// +-------------------------+
// | .dynsym |
// | Elf_Sym STN_UNDEF |
@@ -615,6 +616,10 @@ class ElfBuilder FINAL {
// | ... |
// | Elf_Word chain[c - 1] |
// +-------------------------+
+ // | .eh_frame | (Optional)
+ // +-------------------------+
+ // | .eh_frame_hdr | (Optional)
+ // +-------------------------+
// | .rodata |
// | oatdata..oatexec-4 |
// +-------------------------+
@@ -648,22 +653,21 @@ class ElfBuilder FINAL {
// | .shstrtab\0 |
// | .symtab\0 | (Optional)
// | .strtab\0 | (Optional)
- // | .debug_str\0 | (Optional)
- // | .debug_info\0 | (Optional)
// | .eh_frame\0 | (Optional)
- // | .debug_line\0 | (Optional)
+ // | .eh_frame_hdr\0 | (Optional)
+ // | .debug_info\0 | (Optional)
// | .debug_abbrev\0 | (Optional)
+ // | .debug_str\0 | (Optional)
+ // | .debug_line\0 | (Optional)
// +-------------------------+ (Optional)
// | .debug_info | (Optional)
// +-------------------------+ (Optional)
// | .debug_abbrev | (Optional)
// +-------------------------+ (Optional)
- // | .eh_frame | (Optional)
+ // | .debug_str | (Optional)
// +-------------------------+ (Optional)
// | .debug_line | (Optional)
// +-------------------------+ (Optional)
- // | .debug_str | (Optional)
- // +-------------------------+ (Optional)
// | Elf_Shdr NULL |
// | Elf_Shdr .dynsym |
// | Elf_Shdr .dynstr |
@@ -673,11 +677,12 @@ class ElfBuilder FINAL {
// | Elf_Shdr .bss | (Optional)
// | Elf_Shdr .dynamic |
// | Elf_Shdr .shstrtab |
+ // | Elf_Shdr .eh_frame | (Optional)
+ // | Elf_Shdr .eh_frame_hdr | (Optional)
// | Elf_Shdr .debug_info | (Optional)
// | Elf_Shdr .debug_abbrev | (Optional)
- // | Elf_Shdr .eh_frame | (Optional)
- // | Elf_Shdr .debug_line | (Optional)
// | Elf_Shdr .debug_str | (Optional)
+ // | Elf_Shdr .debug_line | (Optional)
// +-------------------------+
if (fatal_error_) {
@@ -718,6 +723,9 @@ class ElfBuilder FINAL {
program_headers_[PH_DYNAMIC].p_type = PT_DYNAMIC;
program_headers_[PH_DYNAMIC].p_flags = PF_R | PF_W;
+ program_headers_[PH_EH_FRAME_HDR].p_type = PT_NULL;
+ program_headers_[PH_EH_FRAME_HDR].p_flags = PF_R;
+
// Get the dynstr string.
dynstr_ = dynsym_builder_.GenerateStrtab();
@@ -828,10 +836,37 @@ class ElfBuilder FINAL {
hash_builder_.GetSection()->sh_size = hash_.size() * sizeof(Elf_Word);
hash_builder_.GetSection()->sh_link = hash_builder_.GetLink();
+ // Get the layout of the extra sections with SHF_ALLOC flag.
+ // This will deal with .eh_frame and .eh_frame_hdr.
+ // .eh_frame contains relative pointers to .text which we
+ // want to fixup between the calls to Init() and Write().
+ // Therefore we handle those sections here as opposed to Write().
+ // It also has the nice side effect of including .eh_frame
+ // with the rest of LOAD_R segment. It must come before .rodata
+ // because .rodata and .text must be next to each other.
+ Elf_Shdr* prev = hash_builder_.GetSection();
+ for (auto* it : other_builders_) {
+ if ((it->GetSection()->sh_flags & SHF_ALLOC) != 0) {
+ it->GetSection()->sh_offset = NextOffset<Elf_Word, Elf_Shdr>(*it->GetSection(), *prev);
+ it->GetSection()->sh_addr = it->GetSection()->sh_offset;
+ it->GetSection()->sh_size = it->GetBuffer()->size();
+ it->GetSection()->sh_link = it->GetLink();
+ prev = it->GetSection();
+ }
+ }
+ // If the sections exist, check that they have been handled.
+ const auto* eh_frame = FindRawSection(".eh_frame");
+ if (eh_frame != nullptr) {
+ DCHECK_NE(eh_frame->GetSection()->sh_offset, 0u);
+ }
+ const auto* eh_frame_hdr = FindRawSection(".eh_frame_hdr");
+ if (eh_frame_hdr != nullptr) {
+ DCHECK_NE(eh_frame_hdr->GetSection()->sh_offset, 0u);
+ }
+
// Get the layout of the rodata section.
rodata_builder_.GetSection()->sh_offset =
- NextOffset<Elf_Word, Elf_Shdr>(*rodata_builder_.GetSection(),
- *hash_builder_.GetSection());
+ NextOffset<Elf_Word, Elf_Shdr>(*rodata_builder_.GetSection(), *prev);
rodata_builder_.GetSection()->sh_addr = rodata_builder_.GetSection()->sh_offset;
rodata_builder_.GetSection()->sh_size = rodata_builder_.GetSize();
rodata_builder_.GetSection()->sh_link = rodata_builder_.GetLink();
@@ -909,9 +944,7 @@ class ElfBuilder FINAL {
}
// Setup all the other sections.
- for (ElfRawSectionBuilder<Elf_Word, Elf_Sword, Elf_Shdr> *builder = other_builders_.data(),
- *end = builder + other_builders_.size();
- builder != end; ++builder) {
+ for (auto* builder : other_builders_) {
section_ptrs_.push_back(builder->GetSection());
AssignSectionStr(builder, &shstrtab_);
builder->SetSectionIndex(section_index_);
@@ -958,20 +991,22 @@ class ElfBuilder FINAL {
}
}
- // Get the layout of the extra sections. (This will deal with the debug
- // sections if they are there)
- for (auto it = other_builders_.begin(); it != other_builders_.end(); ++it) {
- it->GetSection()->sh_offset = NextOffset<Elf_Word, Elf_Shdr>(*it->GetSection(), *prev);
- it->GetSection()->sh_addr = 0;
- it->GetSection()->sh_size = it->GetBuffer()->size();
- it->GetSection()->sh_link = it->GetLink();
-
- // We postpone adding an ElfFilePiece to keep the order in "pieces."
-
- prev = it->GetSection();
- if (debug_logging_) {
- LOG(INFO) << it->GetName() << " off=" << it->GetSection()->sh_offset
- << " size=" << it->GetSection()->sh_size;
+ // Get the layout of the extra sections without SHF_ALLOC flag.
+ // (This will deal with the debug sections if they are there)
+ for (auto* it : other_builders_) {
+ if ((it->GetSection()->sh_flags & SHF_ALLOC) == 0) {
+ it->GetSection()->sh_offset = NextOffset<Elf_Word, Elf_Shdr>(*it->GetSection(), *prev);
+ it->GetSection()->sh_addr = 0;
+ it->GetSection()->sh_size = it->GetBuffer()->size();
+ it->GetSection()->sh_link = it->GetLink();
+
+ // We postpone adding an ElfFilePiece to keep the order in "pieces."
+
+ prev = it->GetSection();
+ if (debug_logging_) {
+ LOG(INFO) << it->GetName() << " off=" << it->GetSection()->sh_offset
+ << " size=" << it->GetSection()->sh_size;
+ }
}
}
@@ -1044,6 +1079,26 @@ class ElfBuilder FINAL {
program_headers_[PH_DYNAMIC].p_memsz = dynamic_builder_.GetSection()->sh_size;
program_headers_[PH_DYNAMIC].p_align = dynamic_builder_.GetSection()->sh_addralign;
+ const auto* eh_frame_hdr = FindRawSection(".eh_frame_hdr");
+ if (eh_frame_hdr != nullptr) {
+ const auto* eh_frame = FindRawSection(".eh_frame");
+ // Check layout:
+ // 1) eh_frame is before eh_frame_hdr.
+ // 2) There's no gap.
+ CHECK(eh_frame != nullptr);
+ CHECK_LE(eh_frame->GetSection()->sh_offset, eh_frame_hdr->GetSection()->sh_offset);
+ CHECK_EQ(eh_frame->GetSection()->sh_offset + eh_frame->GetSection()->sh_size,
+ eh_frame_hdr->GetSection()->sh_offset);
+
+ program_headers_[PH_EH_FRAME_HDR].p_type = PT_GNU_EH_FRAME;
+ program_headers_[PH_EH_FRAME_HDR].p_offset = eh_frame_hdr->GetSection()->sh_offset;
+ program_headers_[PH_EH_FRAME_HDR].p_vaddr = eh_frame_hdr->GetSection()->sh_addr;
+ program_headers_[PH_EH_FRAME_HDR].p_paddr = eh_frame_hdr->GetSection()->sh_addr;
+ program_headers_[PH_EH_FRAME_HDR].p_filesz = eh_frame_hdr->GetSection()->sh_size;
+ program_headers_[PH_EH_FRAME_HDR].p_memsz = eh_frame_hdr->GetSection()->sh_size;
+ program_headers_[PH_EH_FRAME_HDR].p_align = eh_frame_hdr->GetSection()->sh_addralign;
+ }
+
// Finish setup of the Ehdr values.
elf_header_.e_phoff = PHDR_OFFSET;
elf_header_.e_shoff = sections_offset;
@@ -1108,7 +1163,7 @@ class ElfBuilder FINAL {
}
// Postponed debug info.
- for (auto it = other_builders_.begin(); it != other_builders_.end(); ++it) {
+ for (auto* it : other_builders_) {
pieces.push_back(new ElfFileMemoryPiece<Elf_Word>(it->GetName(), it->GetSection()->sh_offset,
it->GetBuffer()->data(),
it->GetBuffer()->size()));
@@ -1125,12 +1180,21 @@ class ElfBuilder FINAL {
return true;
}
- // Adds the given raw section to the builder. This will copy it. The caller
- // is responsible for deallocating their copy.
- void RegisterRawSection(ElfRawSectionBuilder<Elf_Word, Elf_Sword, Elf_Shdr> bld) {
+ // Adds the given raw section to the builder. It does not take ownership.
+ void RegisterRawSection(ElfRawSectionBuilder<Elf_Word, Elf_Sword, Elf_Shdr>* bld) {
other_builders_.push_back(bld);
}
+ const ElfRawSectionBuilder<Elf_Word, Elf_Sword, Elf_Shdr>*
+ FindRawSection(const char* name) {
+ for (const auto* other_builder : other_builders_) {
+ if (other_builder->GetName() == name) {
+ return other_builder;
+ }
+ }
+ return nullptr;
+ }
+
private:
void SetISA(InstructionSet isa) {
switch (isa) {
@@ -1282,7 +1346,8 @@ class ElfBuilder FINAL {
PH_LOAD_RW_BSS = 3,
PH_LOAD_RW_DYNAMIC = 4,
PH_DYNAMIC = 5,
- PH_NUM = 6,
+ PH_EH_FRAME_HDR = 6,
+ PH_NUM = 7,
};
static const uint32_t PHDR_SIZE = sizeof(Elf_Phdr) * PH_NUM;
Elf_Phdr program_headers_[PH_NUM];
@@ -1306,7 +1371,7 @@ class ElfBuilder FINAL {
ElfSectionBuilder<Elf_Word, Elf_Sword, Elf_Shdr> hash_builder_;
ElfDynamicBuilder<Elf_Word, Elf_Sword, Elf_Dyn, Elf_Shdr> dynamic_builder_;
ElfSectionBuilder<Elf_Word, Elf_Sword, Elf_Shdr> shstrtab_builder_;
- std::vector<ElfRawSectionBuilder<Elf_Word, Elf_Sword, Elf_Shdr>> other_builders_;
+ std::vector<ElfRawSectionBuilder<Elf_Word, Elf_Sword, Elf_Shdr>*> other_builders_;
DISALLOW_COPY_AND_ASSIGN(ElfBuilder);
};
generated by cgit v1.2.3-59-g8ed1b (git 2.39.0) at 2025-10-22 06:57:15 +0000