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