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Throw more light into .eh_frame and other

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David Gonzalez Martin 2024-09-28 20:57:01 -06:00 committed by David
parent 26944f4e53
commit 8249595e9c
1 changed files with 60 additions and 52 deletions
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112
bootstrap/main.c
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@ -7654,7 +7654,6 @@ STRUCT(EhFrameHeaderEntry)
u32 fde;
};
STRUCT(Uleb128)
{
u64 number;
@ -8483,32 +8482,53 @@ may_be_unused fn void write_elf(Thread* thread, const ObjectOptions* const restr
auto name = elf_get_section_name(builder, strlit(".gnu.version_r"));
ELFVersionRequirementEntry entries[] = {
{
.hash = glibc_225.hash,
.flags = 0,
.index = 3,
.name_offset = glibc_225.offset,
.next = sizeof(ELFVersionRequirementEntry),
},
{
.hash = glibc_234.hash,
.flags = 0,
.index = 2,
.name_offset = glibc_234.offset,
.next = 0,
},
};
ELFVersionRequirement first_requirement = {
.version = 1,
.count = array_length(entries),
.name_offset = libcso6,
.aux_offset = sizeof(ELFVersionRequirement),
.next = 0,
STRUCT(Requirement)
{
ELFVersionRequirement req;
ELFVersionRequirementEntry* entry_pointer;
u32 entry_count;
};
*vb_add_struct(&builder->file, ELFVersionRequirement) = first_requirement;
memcpy(vb_add(&builder->file, sizeof(entries)), entries, sizeof(entries));
Requirement requirements[] = {
{
.req = {
.version = 1,
.name_offset = libcso6,
.aux_offset = sizeof(ELFVersionRequirement),
.next = 0,
},
.entry_pointer = (ELFVersionRequirementEntry[]) {
{
.hash = glibc_225.hash,
.flags = 0,
.index = 3,
.name_offset = glibc_225.offset,
.next = sizeof(ELFVersionRequirementEntry),
},
{
.hash = glibc_234.hash,
.flags = 0,
.index = 2,
.name_offset = glibc_234.offset,
.next = 0,
},
},
.entry_count = 2,
}
};
for (u32 i = 0; i < array_length(requirements); i += 1)
{
auto req = &requirements[i];
auto requirement = req->req;
requirement.count = req->entry_count;
*vb_add_struct(&builder->file, ELFVersionRequirement) = requirement;
auto entry_size = req->entry_count * sizeof(*req->entry_pointer);
memcpy(vb_add(&builder->file, entry_size), req->entry_pointer, entry_size);
}
auto size = builder->file.length - offset;
@ -8522,7 +8542,7 @@ may_be_unused fn void write_elf(Thread* thread, const ObjectOptions* const restr
.offset = offset,
.size = size,
.link = dynamic_string_table_index,
.info = 1, // TODO: figure out
.info = array_length(requirements),
.alignment = alignment,
.entry_size = 0,
};
@ -8666,20 +8686,6 @@ may_be_unused fn void write_elf(Thread* thread, const ObjectOptions* const restr
u32 main_offset = 0;
u32 main_size = 0;
// SymbolRelocation _start_libc_start_main_relocation;
// SymbolRelocation _start_main_relocation;
// SymbolRelocation text_1_tmc_end_1_relocation;
// SymbolRelocation text_1_tmc_end_2_relocation;
// SymbolRelocation text_2_tmc_end_1_relocation;
// SymbolRelocation text_2_tmc_end_2_relocation;
// SymbolRelocation text_ITM_deregisterTMCloneTable_relocation;
// SymbolRelocation text_ITM_registerTMCloneTable_relocation;
// SymbolRelocation text_fini_array_tmc_end_1_relocation;
// SymbolRelocation text_fini_array_tmc_end_2_relocation;
// SymbolRelocation text_fini_array_cxa_finalize_1_relocation;
// SymbolRelocation text_fini_array_cxa_finalize_2_relocation;
// SymbolRelocation text_fini_array_dso_handle_relocation;
auto text_section_index = builder->section_headers.length;
{
//.text
@ -9053,6 +9059,8 @@ may_be_unused fn void write_elf(Thread* thread, const ObjectOptions* const restr
u32 eh_frame_size = 0;
u32 eh_frame_alignment = 0;
u32 eh_frame_hdr_section_index = builder->section_headers.length;
u32 eh_frame_header_entries = 0;
EhFrameHeader* eh_frame_header = 0;
{
// .eh_frame_hdr
auto* section_header = vb_add(&builder->section_headers, 1);
@ -9067,25 +9075,18 @@ may_be_unused fn void write_elf(Thread* thread, const ObjectOptions* const restr
// TODO: figure out a link between this and the code
EhFrameHeaderEntry entries[] = {
{ .pc = -4068, .fde = 0x34 },
{ .pc = -3816, .fde = 0x4c },
{ .pc = _start_offset - offset, .fde = 0x34 },
{ .pc = main_offset - offset, .fde = 0x4c },
};
EhFrameHeader eh_frame_hdr = {
.version = 1,
.pointer_encoding = elf_eh_frame_sdata4 | elf_eh_frame_pcrel,
.count_encoding = elf_eh_frame_udata4 | elf_eh_frame_absptr,
.table_encoding = elf_eh_frame_sdata4 | elf_eh_frame_datarel,
.frame_start = 0x18,
.entry_count = array_length(entries),
};
eh_frame_header_entries = array_length(entries);
auto size = sizeof(eh_frame_hdr) + sizeof(entries);
auto size = sizeof(EhFrameHeader) + sizeof(entries);
eh_frame_size = size;
auto* dst = vb_add(&builder->file, size);
eh_frame_header = (EhFrameHeader*)dst;
memcpy(dst, &eh_frame_hdr, sizeof(eh_frame_hdr));
memcpy(dst + sizeof(eh_frame_hdr), entries, sizeof(entries));
memcpy(dst + sizeof(EhFrameHeader), entries, sizeof(entries));
*section_header = (ELFSectionHeader) {
.name_offset = name,
@ -9110,6 +9111,14 @@ may_be_unused fn void write_elf(Thread* thread, const ObjectOptions* const restr
vb_align(&builder->file, alignment);
auto offset = builder->file.length;
*eh_frame_header = (EhFrameHeader){
.version = 1,
.pointer_encoding = elf_eh_frame_sdata4 | elf_eh_frame_pcrel,
.count_encoding = elf_eh_frame_udata4 | elf_eh_frame_absptr,
.table_encoding = elf_eh_frame_sdata4 | elf_eh_frame_datarel,
.frame_start = offset - (((u8*)eh_frame_header - builder->file.pointer) + offsetof(EhFrameHeader, frame_start)),
.entry_count = eh_frame_header_entries,
};
auto name = elf_get_section_name(builder, strlit(".eh_frame"));
@ -9123,7 +9132,6 @@ may_be_unused fn void write_elf(Thread* thread, const ObjectOptions* const restr
auto augmentation = strlit("zR");
memcpy(vb_add(&builder->file, augmentation.length + 1), augmentation.pointer, augmentation.length + 1);
u32 code_alignment_factor = 1;
uleb128_encode(&builder->file, code_alignment_factor);