Module elf 

ELF64 loader for Strat9-OS.

Parses ELF64 headers and loads PT_LOAD segments into a user address space, then creates a kernel task that trampolines into Ring 3 via IRETQ.

Supports :

• ET_EXEC
• ET_DYN (PIE/static-PIE)
• ELF64 little-endian x86_64 binaries.

Does not support (or need future fix) :

• Fix TODO : allocation heap during ELF loading PARTIALLY DONE (#67) : program-header vectors and boot-stack argv pointers now use try_reserve_exact-based fallible collection and fail the load with an error instead of aborting. Full rollback of already-mapped segments still requires a fallible GlobalAlloc.

• Fix TODO : find_free_vma_range : fallback hardcoded 0x1000_0000 DONE : the fallback was removed; a failed search now fails the load with “No virtual range for ET_DYN image”.

Security:

• User stack has a guard page (user_stack_base() - 4096) that is intentionally left unmapped. Stack underflows hit it and page-fault.

Macros

elf_trace 🔒

Structs

Elf64Dyn 🔒

Elf64Header 🔒

Parsed ELF64 file header (copy-friendly, no borrows).

Elf64Phdr 🔒

Parsed ELF64 program header (copy-friendly, packed for raw byte reading).

Elf64Rela 🔒

Elf64Sym 🔒

LoadedElfInfo

Result of loading an ELF image into an address space.

Constants

AT_BASE 🔒

AT_ENTRY 🔒

AT_PAGESZ 🔒

AT_PHDR 🔒

AT_PHENT 🔒

AT_PHNUM 🔒

AT_RANDOM 🔒

DT_JMPREL 🔒

DT_NULL 🔒

DT_PLTREL 🔒

DT_PLTRELSZ 🔒

DT_RELA 🔒

DT_RELACOUNT 🔒

DT_RELAENT 🔒

DT_RELASZ 🔒

DT_RELR 🔒

DT_RELRENT 🔒

DT_RELRSZ 🔒

DT_STRTAB 🔒

DT_SYMENT 🔒

DT_SYMTAB 🔒

ET_DYN 🔒

ET_EXEC 🔒

MAX_INTERP_PATH_LEN 🔒

Maximum PT_INTERP path length we accept.

PF_R 🔒

PF_W 🔒

PF_X 🔒

PT_DYNAMIC 🔒

PT_GNU_RELRO 🔒

PT_GNU_STACK 🔒

PT_INTERP 🔒

PT_LOAD 🔒

PT_TLS 🔒

R_X86_64_64 🔒

R_X86_64_COPY 🔒

R_X86_64_DTPMOD64 🔒

R_X86_64_DTPOFF64 🔒

R_X86_64_GLOB_DAT 🔒

R_X86_64_IRELATIVE 🔒

R_X86_64_JUMP_SLOT 🔒

R_X86_64_RELATIVE 🔒

R_X86_64_TPOFF64 🔒

USER_ADDR_MAX

Maximum virtual address we accept for user-space mappings.

USER_RFLAGS 🔒

Standard user-mode RFLAGS: IF=1, reserved bit 1 set.

USER_STACK_MAX_PAGES

Upper bound on a per-process user stack (2048 pages = 8 MiB), to keep a buggy or hostile caller from exhausting the user address space / frames.

USER_STACK_MIN_PAGES

Lower bound on a per-process user stack (4 pages = 16 KiB): the boot stack layout alone (argv/envp/auxv + guard margins) needs at least one page, and tiny stacks would fault immediately.

USER_STACK_PAGES

Number of 4 KiB pages for the user stack (16 pages = 64 KiB).

Functions

apply_dynamic_relocations 🔒

Performs the apply dynamic relocations operation.

apply_relr_relocations 🔒

Performs the apply relr relocations operation.

apply_segment_permissions 🔒

Performs the apply segment permissions operation.

call_ifunc_resolver 🔒

Calls a user-space IFUNC resolver function and returns its result.

compute_load_bias_and_entry 🔒

Compute load bias and relocated entry for ET_EXEC / ET_DYN.

compute_load_bounds 🔒

Compute total mapped bounds for all PT_LOAD segments.

elf_flags_to_vma 🔒

Convert ELF p_flags to VmaFlags.

elf_ring3_trampoline 🔒

Parameters for the Ring 3 trampoline, stored in a static so the Trampoline that switches to user address space and does IRETQ to Ring 3.

find_relocated_phdr_vaddr 🔒

Performs the find relocated phdr vaddr operation.

generate_aux_random_seed 🔒

load_and_run_elf

Load an ELF64 binary and schedule it as a Ring 3 user task.

load_and_run_elf_with_args

Load an ELF64 binary with command-line arguments and schedule it as a Ring 3 task.

load_and_run_elf_with_caps

Performs the load and run elf with caps operation.

load_and_run_elf_with_stack

Load an ELF64 binary with an explicit per-process user stack size.

load_elf_image

Load an ELF binary into the provided address space. Returns the entry point address.

load_elf_task_inner 🔒

Internal ELF task builder used by all public loading APIs. extra_args are written to the user stack as argv[1..] after the program name.

load_elf_task_with_caps

Thin public wrapper that keeps the existing API stable.

load_segment 🔒

Load a single PT_LOAD segment into the given address space.

parse_header 🔒

Parse and validate the ELF64 file header from raw bytes.

parse_interp_path 🔒

Parses interp path.

pie_base 🔒

Get the randomized PIE base address for ELF loading.

program_headers 🔒

Iterate over program headers in the ELF.

push_auxv 🔒

Performs the push auxv operation.

read_elf_from_vfs 🔒

Reads elf from vfs.

read_user_mapped_bytes 🔒

Reads user mapped bytes.

read_user_mapped_bytes_pub

Reads user mapped bytes pub.

read_user_u64 🔒

Reads user u64.

setup_boot_user_stack 🔒

Performs the setup boot user stack operation. Sets up the initial user-space stack for a freshly loaded ELF task.

try_collect_exact 🔒

Collects an exact-size-hint iterator into a Vec, failing cleanly on allocation failure instead of aborting (issue #67).

user_stack_base 🔒

Get the randomized user stack base address.

user_stack_guard 🔒

Get the guard page address below the user stack.

user_stack_top 🔒

Get the randomized user stack top address.

write_user_mapped_bytes 🔒

Writes user mapped bytes.

write_user_mapped_bytes_pub

Writes user mapped bytes pub.

write_user_u64 🔒

Writes user u64.

write_user_u64_pub

Writes user u64 pub.