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/*
* IA-32 ELF support.
*
* Copyright (C) 1999 Arun Sharma <arun.sharma@intel.com>
* Copyright (C) 2001 Hewlett-Packard Co
* David Mosberger-Tang <davidm@hpl.hp.com>
*
* 06/16/00 A. Mallick initialize csd/ssd/tssd/cflg for ia32_load_state
* 04/13/01 D. Mosberger dropped saving tssd in ar.k1---it's not needed
* 09/14/01 D. Mosberger fixed memory management for gdt/tss page
*/
#include <linux/types.h>
#include <linux/mm.h>
#include <linux/security.h>
#include <asm/param.h>
#include <asm/signal.h>
#include "ia32priv.h"
#include "elfcore32.h"
/* Override some function names */
#undef start_thread
#define start_thread ia32_start_thread
#define elf_format elf32_format
#define init_elf_binfmt init_elf32_binfmt
#define exit_elf_binfmt exit_elf32_binfmt
#undef CLOCKS_PER_SEC
#define CLOCKS_PER_SEC IA32_CLOCKS_PER_SEC
extern void ia64_elf32_init (struct pt_regs *regs);
static void elf32_set_personality (void);
static unsigned long __attribute ((unused))
randomize_stack_top(unsigned long stack_top);
#define setup_arg_pages(bprm,tos,exec) ia32_setup_arg_pages(bprm,exec)
#define elf_map elf32_map
#undef SET_PERSONALITY
#define SET_PERSONALITY(ex) elf32_set_personality()
#define elf_read_implies_exec(ex, have_pt_gnu_stack) (!(have_pt_gnu_stack))
/* Ugly but avoids duplication */
#include "../../../fs/binfmt_elf.c"
extern struct page *ia32_shared_page[];
extern unsigned long *ia32_gdt;
extern struct page *ia32_gate_page;
int
ia32_install_shared_page (struct vm_area_struct *vma, struct vm_fault *vmf)
{
vmf->page = ia32_shared_page[smp_processor_id()];
get_page(vmf->page);
return 0;
}
int
ia32_install_gate_page (struct vm_area_struct *vma, struct vm_fault *vmf)
{
vmf->page = ia32_gate_page;
get_page(vmf->page);
return 0;
}
static const struct vm_operations_struct ia32_shared_page_vm_ops = {
.fault = ia32_install_shared_page
};
static const struct vm_operations_struct ia32_gate_page_vm_ops = {
.fault = ia32_install_gate_page
};
void
ia64_elf32_init (struct pt_regs *regs)
{
struct vm_area_struct *vma;
/*
* Map GDT below 4GB, where the processor can find it. We need to map
* it with privilege level 3 because the IVE uses non-privileged accesses to these
* tables. IA-32 segmentation is used to protect against IA-32 accesses to them.
*/
vma = kmem_cache_zalloc(vm_area_cachep, GFP_KERNEL);
if (vma) {
vma->vm_mm = current->mm;
vma->vm_start = IA32_GDT_OFFSET;
vma->vm_end = vma->vm_start + PAGE_SIZE;
vma->vm_page_prot = PAGE_SHARED;
vma->vm_flags = VM_READ|VM_MAYREAD|VM_RESERVED;
vma->vm_ops = &ia32_shared_page_vm_ops;
down_write(¤t->mm->mmap_sem);
{
if (insert_vm_struct(current->mm, vma)) {
kmem_cache_free(vm_area_cachep, vma);
up_write(¤t->mm->mmap_sem);
BUG();
}
}
up_write(¤t->mm->mmap_sem);
}
/*
* When user stack is not executable, push sigreturn code to stack makes
* segmentation fault raised when returning to kernel. So now sigreturn
* code is locked in specific gate page, which is pointed by pretcode
* when setup_frame_ia32
*/
vma = kmem_cache_zalloc(vm_area_cachep, GFP_KERNEL);
if (vma) {
vma->vm_mm = current->mm;
vma->vm_start = IA32_GATE_OFFSET;
vma->vm_end = vma->vm_start + PAGE_SIZE;
vma->vm_page_prot = PAGE_COPY_EXEC;
vma->vm_flags = VM_READ | VM_MAYREAD | VM_EXEC
| VM_MAYEXEC | VM_RESERVED;
vma->vm_ops = &ia32_gate_page_vm_ops;
down_write(¤t->mm->mmap_sem);
{
if (insert_vm_struct(current->mm, vma)) {
kmem_cache_free(vm_area_cachep, vma);
up_write(¤t->mm->mmap_sem);
BUG();
}
}
up_write(¤t->mm->mmap_sem);
}
/*
* Install LDT as anonymous memory. This gives us all-zero segment descriptors
* until a task modifies them via modify_ldt().
*/
vma = kmem_cache_zalloc(vm_area_cachep, GFP_KERNEL);
if (vma) {
vma->vm_mm = current->mm;
vma->vm_start = IA32_LDT_OFFSET;
vma->vm_end = vma->vm_start + PAGE_ALIGN(IA32_LDT_ENTRIES*IA32_LDT_ENTRY_SIZE);
vma->vm_page_prot = PAGE_SHARED;
vma->vm_flags = VM_READ|VM_WRITE|VM_MAYREAD|VM_MAYWRITE;
down_write(¤t->mm->mmap_sem);
{
if (insert_vm_struct(current->mm, vma)) {
kmem_cache_free(vm_area_cachep, vma);
up_write(¤t->mm->mmap_sem);
BUG();
}
}
up_write(¤t->mm->mmap_sem);
}
ia64_psr(regs)->ac = 0; /* turn off alignment checking */
regs->loadrs = 0;
/*
* According to the ABI %edx points to an `atexit' handler. Since we don't have
* one we'll set it to 0 and initialize all the other registers just to make
* things more deterministic, ala the i386 implementation.
*/
regs->r8 = 0; /* %eax */
regs->r11 = 0; /* %ebx */
regs->r9 = 0; /* %ecx */
regs->r10 = 0; /* %edx */
regs->r13 = 0; /* %ebp */
regs->r14 = 0; /* %esi */
regs->r15 = 0; /* %edi */
current->thread.eflag = IA32_EFLAG;
current->thread.fsr = IA32_FSR_DEFAULT;
current->thread.fcr = IA32_FCR_DEFAULT;
current->thread.fir = 0;
current->thread.fdr = 0;
/*
* Setup GDTD. Note: GDTD is the descrambled version of the pseudo-descriptor
* format defined by Figure 3-11 "Pseudo-Descriptor Format" in the IA-32
* architecture manual. Also note that the only fields that are not ignored are
* `base', `limit', 'G', `P' (must be 1) and `S' (must be 0).
*/
regs->r31 = IA32_SEG_UNSCRAMBLE(IA32_SEG_DESCRIPTOR(IA32_GDT_OFFSET, IA32_PAGE_SIZE - 1,
0, 0, 0, 1, 0, 0, 0));
/* Setup the segment selectors */
regs->r16 = (__USER_DS << 16) | __USER_DS; /* ES == DS, GS, FS are zero */
regs->r17 = (__USER_DS << 16) | __USER_CS; /* SS, CS; ia32_load_state() sets TSS and LDT */
ia32_load_segment_descriptors(current);
ia32_load_state(current);
}
/*
* Undo the override of setup_arg_pages() without this ia32_setup_arg_pages()
* will suffer infinite self recursion.
*/
#undef setup_arg_pages
int
ia32_setup_arg_pages (struct linux_binprm *bprm, int executable_stack)
{
int ret;
ret = setup_arg_pages(bprm, IA32_STACK_TOP, executable_stack);
if (!ret) {
/*
* Can't do it in ia64_elf32_init(). Needs to be done before
* calls to elf32_map()
*/
current->thread.ppl = ia32_init_pp_list();
}
return ret;
}
static void
elf32_set_personality (void)
{
set_personality(PER_LINUX32);
current->thread.map_base = IA32_PAGE_OFFSET/3;
}
static unsigned long
elf32_map(struct file *filep, unsigned long addr, struct elf_phdr *eppnt,
int prot, int type, unsigned long unused)
{
unsigned long pgoff = (eppnt->p_vaddr) & ~IA32_PAGE_MASK;
return ia32_do_mmap(filep, (addr & IA32_PAGE_MASK), eppnt->p_filesz + pgoff, prot, type,
eppnt->p_offset - pgoff);
}
#define cpu_uses_ia32el() (local_cpu_data->family > 0x1f)
static int __init check_elf32_binfmt(void)
{
if (cpu_uses_ia32el()) {
printk("Please use IA-32 EL for executing IA-32 binaries\n");
unregister_binfmt(&elf_format);
}
return 0;
}
module_init(check_elf32_binfmt)
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