mirror of
https://github.com/LadybirdBrowser/ladybird.git
synced 2024-11-10 13:00:29 +03:00
Kernel+LibELF: Move sys$execve()'s loading logic from LibELF to Kernel
It was really weird that ELF loading was performed by the ELF::Loader class instead of just being done by the kernel itself. This patch moves all the layout logic from ELF::Loader over to sys$execve(). The kernel no longer cares about ELF::Loader and instead only uses an ELF::Image as an interpreting wrapper around executables.
This commit is contained in:
Andreas Kling
parent
d7ad082afa
commit
7551a66f73
Notes:
sideshowbarker
2024-07-19 00:37:19 +09:00
Author: https://github.com/awesomekling Commit: https://github.com/SerenityOS/serenity/commit/7551a66f738
@ -38,7 +38,7 @@
|
||||
#include <Kernel/VM/Region.h>
|
||||
#include <Kernel/VM/SharedInodeVMObject.h>
|
||||
#include <LibC/limits.h>
|
||||
#include <LibELF/Loader.h>
|
||||
#include <LibELF/Image.h>
|
||||
#include <LibELF/Validation.h>
|
||||
|
||||
//#define EXEC_DEBUG
|
||||
@ -84,8 +84,9 @@ KResultOr<Process::LoadResult> Process::load_elf_object(FileDescription& object_
|
||||
|
||||
MM.enter_process_paging_scope(*this);
|
||||
String object_name = LexicalPath(object_description.absolute_path()).basename();
|
||||
RefPtr<ELF::Loader> loader = ELF::Loader::create(region->vaddr().as_ptr(), loader_metadata.size, move(object_name));
|
||||
loader->map_section_hook = [&](VirtualAddress vaddr, size_t size, size_t alignment, size_t offset_in_image, bool is_readable, bool is_writable, bool is_executable, const String& name) -> u8* {
|
||||
auto elf_image = ELF::Image(region->vaddr().as_ptr(), loader_metadata.size);
|
||||
|
||||
auto map_section_hook = [&](VirtualAddress vaddr, size_t size, size_t alignment, size_t offset_in_image, bool is_readable, bool is_writable, bool is_executable, const String& name) -> u8* {
|
||||
ASSERT(size);
|
||||
ASSERT(alignment == PAGE_SIZE);
|
||||
int prot = 0;
|
||||
@ -103,7 +104,8 @@ KResultOr<Process::LoadResult> Process::load_elf_object(FileDescription& object_
|
||||
}
|
||||
return nullptr;
|
||||
};
|
||||
loader->alloc_section_hook = [&](VirtualAddress vaddr, size_t size, size_t alignment, bool is_readable, bool is_writable, const String& name) -> u8* {
|
||||
|
||||
auto alloc_section_hook = [&](VirtualAddress vaddr, size_t size, size_t alignment, bool is_readable, bool is_writable, const String& name) -> u8* {
|
||||
ASSERT(size);
|
||||
ASSERT(alignment == PAGE_SIZE);
|
||||
int prot = 0;
|
||||
@ -115,36 +117,101 @@ KResultOr<Process::LoadResult> Process::load_elf_object(FileDescription& object_
|
||||
return region->vaddr().as_ptr();
|
||||
return nullptr;
|
||||
};
|
||||
if (should_allocate_tls == ShouldAllocateTls::Yes) {
|
||||
loader->tls_section_hook = [&](size_t size, size_t alignment) {
|
||||
|
||||
auto tls_section_hook = [&](size_t size, size_t alignment) {
|
||||
ASSERT(should_allocate_tls == ShouldAllocateTls::Yes);
|
||||
ASSERT(size);
|
||||
master_tls_region = allocate_region({}, size, String(), PROT_READ | PROT_WRITE);
|
||||
master_tls_size = size;
|
||||
master_tls_alignment = alignment;
|
||||
return master_tls_region->vaddr().as_ptr();
|
||||
};
|
||||
}
|
||||
|
||||
ASSERT(!Processor::current().in_critical());
|
||||
bool success = loader->load();
|
||||
if (!success) {
|
||||
|
||||
bool failed = false;
|
||||
elf_image.for_each_program_header([&](const ELF::Image::ProgramHeader& program_header) {
|
||||
if (program_header.type() == PT_TLS) {
|
||||
auto* tls_image = tls_section_hook(program_header.size_in_memory(), program_header.alignment());
|
||||
if (!tls_image) {
|
||||
failed = true;
|
||||
return;
|
||||
}
|
||||
if (!elf_image.is_within_image(program_header.raw_data(), program_header.size_in_image())) {
|
||||
dbg() << "Shenanigans! ELF PT_TLS header sneaks outside of executable.";
|
||||
failed = true;
|
||||
return;
|
||||
}
|
||||
if (!copy_to_user(tls_image, program_header.raw_data(), program_header.size_in_image())) {
|
||||
failed = false;
|
||||
return;
|
||||
}
|
||||
return;
|
||||
}
|
||||
if (program_header.type() != PT_LOAD)
|
||||
return;
|
||||
if (program_header.is_writable()) {
|
||||
auto* allocated_section = alloc_section_hook(
|
||||
program_header.vaddr(),
|
||||
program_header.size_in_memory(),
|
||||
program_header.alignment(),
|
||||
program_header.is_readable(),
|
||||
program_header.is_writable(),
|
||||
String::format("%s-alloc-%s%s", m_name.is_empty() ? "elf" : m_name.characters(), program_header.is_readable() ? "r" : "", program_header.is_writable() ? "w" : ""));
|
||||
if (!allocated_section) {
|
||||
failed = true;
|
||||
return;
|
||||
}
|
||||
if (!elf_image.is_within_image(program_header.raw_data(), program_header.size_in_image())) {
|
||||
dbg() << "Shenanigans! Writable ELF PT_LOAD header sneaks outside of executable.";
|
||||
failed = true;
|
||||
return;
|
||||
}
|
||||
// It's not always the case with PIE executables (and very well shouldn't be) that the
|
||||
// virtual address in the program header matches the one we end up giving the process.
|
||||
// In order to copy the data image correctly into memory, we need to copy the data starting at
|
||||
// the right initial page offset into the pages allocated for the elf_alloc-XX section.
|
||||
// FIXME: There's an opportunity to munmap, or at least mprotect, the padding space between
|
||||
// the .text and .data PT_LOAD sections of the executable.
|
||||
// Accessing it would definitely be a bug.
|
||||
auto page_offset = program_header.vaddr();
|
||||
page_offset.mask(~PAGE_MASK);
|
||||
if (!copy_to_user((u8*)allocated_section + page_offset.get(), program_header.raw_data(), program_header.size_in_image())) {
|
||||
failed = false;
|
||||
return;
|
||||
}
|
||||
} else {
|
||||
auto* mapped_section = map_section_hook(
|
||||
program_header.vaddr(),
|
||||
program_header.size_in_memory(),
|
||||
program_header.alignment(),
|
||||
program_header.offset(),
|
||||
program_header.is_readable(),
|
||||
program_header.is_writable(),
|
||||
program_header.is_executable(),
|
||||
String::format("%s-map-%s%s%s", m_name.is_empty() ? "elf" : m_name.characters(), program_header.is_readable() ? "r" : "", program_header.is_writable() ? "w" : "", program_header.is_executable() ? "x" : ""));
|
||||
if (!mapped_section) {
|
||||
failed = true;
|
||||
}
|
||||
}
|
||||
});
|
||||
|
||||
if (failed) {
|
||||
klog() << "do_exec: Failure loading program";
|
||||
return KResult(-ENOEXEC);
|
||||
}
|
||||
|
||||
if (!loader->entry().offset(load_offset).get()) {
|
||||
klog() << "do_exec: Failure loading program, entry pointer is invalid! (" << loader->entry().offset(load_offset) << ")";
|
||||
if (!elf_image.entry().offset(load_offset).get()) {
|
||||
klog() << "do_exec: Failure loading program, entry pointer is invalid! (" << elf_image.entry().offset(load_offset) << ")";
|
||||
return KResult(-ENOEXEC);
|
||||
}
|
||||
|
||||
// NOTE: At this point, we've committed to the new executable.
|
||||
|
||||
return LoadResult {
|
||||
load_base_address,
|
||||
loader->entry().offset(load_offset).get(),
|
||||
elf_image.entry().offset(load_offset).get(),
|
||||
(size_t)loader_metadata.size,
|
||||
VirtualAddress(loader->image().program_header_table_offset()).offset(load_offset).get(),
|
||||
loader->image().program_header_count(),
|
||||
VirtualAddress(elf_image.program_header_table_offset()).offset(load_offset).get(),
|
||||
elf_image.program_header_count(),
|
||||
master_tls_region ? master_tls_region->make_weak_ptr() : nullptr,
|
||||
master_tls_size,
|
||||
master_tls_alignment
|
||||
|
||||
@ -29,20 +29,12 @@
|
||||
#include <AK/Memory.h>
|
||||
#include <AK/QuickSort.h>
|
||||
|
||||
#ifdef KERNEL
|
||||
# include <Kernel/VM/MemoryManager.h>
|
||||
# define do_memcpy copy_to_user
|
||||
#else
|
||||
# define do_memcpy memcpy
|
||||
#endif
|
||||
|
||||
//#define Loader_DEBUG
|
||||
|
||||
namespace ELF {
|
||||
|
||||
Loader::Loader(const u8* buffer, size_t size, String&& name, bool verbose_logging)
|
||||
Loader::Loader(const u8* buffer, size_t size, String&&, bool verbose_logging)
|
||||
: m_image(buffer, size, verbose_logging)
|
||||
, m_name(move(name))
|
||||
{
|
||||
if (m_image.is_valid())
|
||||
m_symbol_count = m_image.symbol_count();
|
||||
@ -52,98 +44,6 @@ Loader::~Loader()
|
||||
{
|
||||
}
|
||||
|
||||
bool Loader::load()
|
||||
{
|
||||
#ifdef Loader_DEBUG
|
||||
m_image.dump();
|
||||
#endif
|
||||
if (!m_image.is_valid())
|
||||
return false;
|
||||
|
||||
if (!layout())
|
||||
return false;
|
||||
|
||||
return true;
|
||||
}
|
||||
|
||||
bool Loader::layout()
|
||||
{
|
||||
bool failed = false;
|
||||
m_image.for_each_program_header([&](const Image::ProgramHeader& program_header) {
|
||||
if (program_header.type() == PT_TLS) {
|
||||
#ifdef KERNEL
|
||||
auto* tls_image = tls_section_hook(program_header.size_in_memory(), program_header.alignment());
|
||||
if (!tls_image) {
|
||||
failed = true;
|
||||
return;
|
||||
}
|
||||
if (!m_image.is_within_image(program_header.raw_data(), program_header.size_in_image())) {
|
||||
dbg() << "Shenanigans! ELF PT_TLS header sneaks outside of executable.";
|
||||
failed = true;
|
||||
return;
|
||||
}
|
||||
if (!do_memcpy(tls_image, program_header.raw_data(), program_header.size_in_image())) {
|
||||
failed = false;
|
||||
return;
|
||||
}
|
||||
#endif
|
||||
return;
|
||||
}
|
||||
if (program_header.type() != PT_LOAD)
|
||||
return;
|
||||
#ifdef KERNEL
|
||||
# ifdef Loader_DEBUG
|
||||
kprintf("PH: V%p %u r:%u w:%u\n", program_header.vaddr().get(), program_header.size_in_memory(), program_header.is_readable(), program_header.is_writable());
|
||||
# endif
|
||||
if (program_header.is_writable()) {
|
||||
auto* allocated_section = alloc_section_hook(
|
||||
program_header.vaddr(),
|
||||
program_header.size_in_memory(),
|
||||
program_header.alignment(),
|
||||
program_header.is_readable(),
|
||||
program_header.is_writable(),
|
||||
String::format("%s-alloc-%s%s", m_name.is_empty() ? "elf" : m_name.characters(), program_header.is_readable() ? "r" : "", program_header.is_writable() ? "w" : ""));
|
||||
if (!allocated_section) {
|
||||
failed = true;
|
||||
return;
|
||||
}
|
||||
if (!m_image.is_within_image(program_header.raw_data(), program_header.size_in_image())) {
|
||||
dbg() << "Shenanigans! Writable ELF PT_LOAD header sneaks outside of executable.";
|
||||
failed = true;
|
||||
return;
|
||||
}
|
||||
// It's not always the case with PIE executables (and very well shouldn't be) that the
|
||||
// virtual address in the program header matches the one we end up giving the process.
|
||||
// In order to copy the data image correctly into memory, we need to copy the data starting at
|
||||
// the right initial page offset into the pages allocated for the elf_alloc-XX section.
|
||||
// FIXME: There's an opportunity to munmap, or at least mprotect, the padding space between
|
||||
// the .text and .data PT_LOAD sections of the executable.
|
||||
// Accessing it would definitely be a bug.
|
||||
auto page_offset = program_header.vaddr();
|
||||
page_offset.mask(~PAGE_MASK);
|
||||
if (!do_memcpy((u8*)allocated_section + page_offset.get(), program_header.raw_data(), program_header.size_in_image())) {
|
||||
failed = false;
|
||||
return;
|
||||
}
|
||||
} else {
|
||||
auto* mapped_section = map_section_hook(
|
||||
program_header.vaddr(),
|
||||
program_header.size_in_memory(),
|
||||
program_header.alignment(),
|
||||
program_header.offset(),
|
||||
program_header.is_readable(),
|
||||
program_header.is_writable(),
|
||||
program_header.is_executable(),
|
||||
String::format("%s-map-%s%s%s", m_name.is_empty() ? "elf" : m_name.characters(), program_header.is_readable() ? "r" : "", program_header.is_writable() ? "w" : "", program_header.is_executable() ? "x" : ""));
|
||||
if (!mapped_section) {
|
||||
failed = true;
|
||||
}
|
||||
}
|
||||
#endif
|
||||
});
|
||||
return !failed;
|
||||
}
|
||||
|
||||
#ifndef KERNEL
|
||||
Optional<Image::Symbol> Loader::find_symbol(u32 address, u32* out_offset) const
|
||||
{
|
||||
|
||||
@ -48,12 +48,6 @@ public:
|
||||
static NonnullRefPtr<Loader> create(const u8* data, size_t size, String&& name = String::empty(), bool verbose_logging = true) { return adopt(*new Loader(data, size, move(name), verbose_logging)); }
|
||||
~Loader();
|
||||
|
||||
bool load();
|
||||
#if defined(KERNEL)
|
||||
Function<void*(VirtualAddress, size_t, size_t, bool, bool, const String&)> alloc_section_hook;
|
||||
Function<void*(size_t, size_t)> tls_section_hook;
|
||||
Function<void*(VirtualAddress, size_t, size_t, size_t, bool r, bool w, bool x, const String&)> map_section_hook;
|
||||
#endif
|
||||
VirtualAddress entry() const
|
||||
{
|
||||
return m_image.entry();
|
||||
@ -75,22 +69,17 @@ private:
|
||||
bool layout();
|
||||
|
||||
Image m_image;
|
||||
String m_name;
|
||||
|
||||
size_t m_symbol_count { 0 };
|
||||
|
||||
struct SortedSymbol {
|
||||
u32 address;
|
||||
StringView name;
|
||||
#ifndef KERNEL
|
||||
String demangled_name;
|
||||
Optional<Image::Symbol> symbol;
|
||||
#endif
|
||||
};
|
||||
|
||||
#ifndef KERNEL
|
||||
mutable Vector<SortedSymbol> m_sorted_symbols;
|
||||
#endif
|
||||
};
|
||||
|
||||
} // end namespace ELF
|
||||
|
||||
Loading…
Reference in New Issue
Block a user