/* * IA-32 ELF support. * * Copyright (C) 1999 Arun Sharma * Copyright (C) 2001 Hewlett-Packard Co * David Mosberger-Tang * * 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 #include #include #include #include #include #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); #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, ibcs2) 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; struct page * ia32_install_shared_page (struct vm_area_struct *vma, unsigned long address, int *type) { struct page *pg = ia32_shared_page[smp_processor_id()]; get_page(pg); if (type) *type = VM_FAULT_MINOR; return pg; } struct page * ia32_install_gate_page (struct vm_area_struct *vma, unsigned long address, int *type) { struct page *pg = ia32_gate_page; get_page(pg); if (type) *type = VM_FAULT_MINOR; return pg; } static struct vm_operations_struct ia32_shared_page_vm_ops = { .nopage = ia32_install_shared_page }; static struct vm_operations_struct ia32_gate_page_vm_ops = { .nopage = 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_alloc(vm_area_cachep, SLAB_KERNEL); if (vma) { memset(vma, 0, sizeof(*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_alloc(vm_area_cachep, SLAB_KERNEL); if (vma) { memset(vma, 0, sizeof(*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_alloc(vm_area_cachep, SLAB_KERNEL); if (vma) { memset(vma, 0, sizeof(*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 regs->r17 = (__USER_DS ia32_load_segment_descriptors(current); ia32_load_state(current); } int ia32_setup_arg_pages (struct linux_binprm *bprm, int executable_stack) { unsigned long stack_base; struct vm_area_struct *mpnt; struct mm_struct *mm = current->mm; int i, ret; stack_base = IA32_STACK_TOP - MAX_ARG_PAGES*PAGE_SIZE; mm->arg_start = bprm->p + stack_base; bprm->p += stack_base; if (bprm->loader) bprm->loader += stack_base; bprm->exec += stack_base; mpnt = kmem_cache_alloc(vm_area_cachep, SLAB_KERNEL); if (!mpnt) return -ENOMEM; memset(mpnt, 0, sizeof(*mpnt)); down_write(¤t->mm->mmap_sem); { mpnt->vm_mm = current->mm; mpnt->vm_start = PAGE_MASK & (unsigned long) bprm->p; mpnt->vm_end = IA32_STACK_TOP; if (executable_stack == EXSTACK_ENABLE_X) mpnt->vm_flags = VM_STACK_FLAGS | VM_EXEC; else if (executable_stack == EXSTACK_DISABLE_X) mpnt->vm_flags = VM_STACK_FLAGS & ~VM_EXEC; else mpnt->vm_flags = VM_STACK_FLAGS; mpnt->vm_page_prot = (mpnt->vm_flags & VM_EXEC)? PAGE_COPY_EXEC: PAGE_COPY; if ((ret = insert_vm_struct(current->mm, mpnt))) { up_write(¤t->mm->mmap_sem); kmem_cache_free(vm_area_cachep, mpnt); return ret; } current->mm->stack_vm = current->mm->total_vm = vma_pages(mpnt); } for (i = 0 ; i < MAX_ARG_PAGES ; i++) { struct page *page = bprm->page[i]; if (page) { bprm->page[i] = NULL; install_arg_page(mpnt, page, stack_base); } stack_base += PAGE_SIZE; } up_write(¤t->mm->mmap_sem); /* 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 0; } 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 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"); return unregister_binfmt(&elf_format); } return 0; } module_init(check_elf32_binfmt)
