elf.c File Reference

The ELF loader. More...

#include <core/system.h>
#include <core/panic.h>
#include <core/arch.h>
#include <sys/proc.h>
#include <sys/sched.h>
#include <sys/elf.h>
#include <mm/vm.h>

Go to the source code of this file.

Macros
#define	ELF_CLASS   ELFCLASS64

Typedefs
typedef struct elf64_hdr	elf_hdr
typedef struct elf64_phdr	elf_phdr

Functions
static int	binfmt_elf_load_segments (struct proc *proc, struct vnode *vnode)
	Maps the loadable segments of an ELF file into a process, and sets its entry point and the start of its heap.
int	binfmt_elf_check (struct vnode *vnode)
	Says whether a file is an ELF program this kernel can run: its magic number, class and machine.
int	binfmt_elf_load (struct proc *proc, const char *path, struct vnode *vnode)
	Loads an ELF program into a process.

Detailed Description

The ELF loader.

A program's loadable segments (PT_LOAD) are mapped from its file, lazily: the pages are read in by page faults, when the program first touches them. A writable segment is copied on write, so that the file stays as it is. The heap starts after the last segment.

Definition in file elf.c.

Macro Definition Documentation

ELF_CLASS

#define ELF_CLASS   ELFCLASS64

Definition at line 31 of file elf.c.

Referenced by binfmt_elf_check(), and binfmt_elf_load_segments().

Typedef Documentation

elf_hdr

typedef struct elf64_hdr elf_hdr

Definition at line 32 of file elf.c.

elf_phdr

typedef struct elf64_phdr elf_phdr

Definition at line 33 of file elf.c.

Function Documentation

binfmt_elf_check()

int binfmt_elf_check

(

struct vnode *

vnode

)

Says whether a file is an ELF program this kernel can run: its magic number, class and machine.

It is checked before the process's old program is destroyed.

Parameters

vnode

the file

Returns

0 if it is, or -ENOEXEC

Definition at line 199 of file elf.c.

References binfmt_elf_check(), elf32_hdr::e_ident, elf32_hdr::e_machine, EI_CLASS, EI_MAG0, EI_MAG1, EI_MAG2, EI_MAG3, ELF_CLASS, ELF_MACHINE, ELFMAG0, ELFMAG1, ELFMAG2, ELFMAG3, and vfs_read().

Referenced by binfmt_elf_check().

binfmt_elf_load()

int binfmt_elf_load	(	struct proc *	proc,
		const char *	path,
		struct vnode *	vnode )

Loads an ELF program into a process.

Parameters

proc	the process, whose address space is empty
path	not used
vnode	the program's file

Returns

0, -EINVAL or -ENOMEM

Definition at line 227 of file elf.c.

References binfmt_elf_load(), and binfmt_elf_load_segments().

Referenced by binfmt_elf_load().

binfmt_elf_load_segments()

int binfmt_elf_load_segments ( struct proc * proc, struct vnode * vnode )

static

Maps the loadable segments of an ELF file into a process, and sets its entry point and the start of its heap.

Returns 0, -EINVAL for a file whose headers aren't valid, or -ENOMEM. On failure, the mappings added so far are left for the caller to release.

Definition at line 42 of file elf.c.

References vm_entry::base, binfmt_elf_load_segments(), elf64_hdr::e_entry, elf64_hdr::e_ident, elf64_hdr::e_machine, elf64_hdr::e_phentsize, elf64_hdr::e_phnum, elf64_hdr::e_phoff, EI_CLASS, ELF_CLASS, ELF_MACHINE, proc::entry, vm_entry::flags, proc::heap, proc::heap_start, kfree(), memset(), vm_entry::off, elf64_phdr::p_filesz, elf64_phdr::p_flags, elf64_phdr::p_memsz, elf64_phdr::p_offset, elf64_phdr::p_type, elf64_phdr::p_vaddr, PAGE_ALIGN, PAGE_MASK, PAGE_ROUND, PF_R, PF_W, PF_X, PT_LOAD, vm_entry::qnode, vm_entry::size, USER_STACK_BASE, vfs_read(), VM_COPY, vm_space::vm_entries, vm_entry_new(), vm_entry::vm_object, vm_object_incref(), vm_object_vnode(), proc::vm_space, VM_UR, VM_UW, and VM_UX.

Referenced by binfmt_elf_load(), and binfmt_elf_load_segments().