arch/ia64/ia32/binfmt_elf32.c

   1 /*
   2  * IA-32 ELF support.
   3  *
   4  * Copyright (C) 1999 Arun Sharma <arun.sharma@intel.com>
   5  * Copyright (C) 2001 Hewlett-Packard Co
   6  *      David Mosberger-Tang <davidm@hpl.hp.com>
   7  *
   8  * 06/16/00     A. Mallick      initialize csd/ssd/tssd/cflg for ia32_load_state
   9  * 04/13/01     D. Mosberger    dropped saving tssd in ar.k1---it's not needed
  10  * 09/14/01     D. Mosberger    fixed memory management for gdt/tss page
  11  */
  12 #include <linux/config.h>
  13
  14 #include <linux/types.h>
  15 #include <linux/mm.h>
  16 #include <linux/security.h>
  17
  18 #include <asm/param.h>
  19 #include <asm/signal.h>
  20
  21 #include "ia32priv.h"
  22 #include "elfcore32.h"
  23
  24 /* Override some function names */
  25 #undef start_thread
  26 #define start_thread                    ia32_start_thread
  27 #define elf_format                      elf32_format
  28 #define init_elf_binfmt                 init_elf32_binfmt
  29 #define exit_elf_binfmt                 exit_elf32_binfmt
  30
  31 #undef CLOCKS_PER_SEC
  32 #define CLOCKS_PER_SEC  IA32_CLOCKS_PER_SEC
  33
  34 extern void ia64_elf32_init (struct pt_regs *regs);
  35
  36 static void elf32_set_personality (void);
  37
  38 #define setup_arg_pages(bprm,exec)              ia32_setup_arg_pages(bprm,exec)
  39 #define elf_map                         elf32_map
  40
  41 #undef SET_PERSONALITY
  42 #define SET_PERSONALITY(ex, ibcs2)      elf32_set_personality()
  43
  44 #define elf_read_implies_exec(ex, have_pt_gnu_stack)    (!(have_pt_gnu_stack))
  45
  46 /* Ugly but avoids duplication */
  47 #include "../../../fs/binfmt_elf.c"
  48
  49 extern struct page *ia32_shared_page[];
  50 extern unsigned long *ia32_gdt;
  51
  52 struct page *
  53 ia32_install_shared_page (struct vm_area_struct *vma, unsigned long address, int *type)
  54 {
  55         struct page *pg = ia32_shared_page[smp_processor_id()];
  56         get_page(pg);
  57         if (type)
  58                 *type = VM_FAULT_MINOR;
  59         return pg;
  60 }
  61
  62 static struct vm_operations_struct ia32_shared_page_vm_ops = {
  63         .nopage = ia32_install_shared_page
  64 };
  65
  66 void
  67 ia64_elf32_init (struct pt_regs *regs)
  68 {
  69         struct vm_area_struct *vma;
  70
  71         /*
  72          * Map GDT below 4GB, where the processor can find it.  We need to map
  73          * it with privilege level 3 because the IVE uses non-privileged accesses to these
  74          * tables.  IA-32 segmentation is used to protect against IA-32 accesses to them.
  75          */
  76         vma = kmem_cache_alloc(vm_area_cachep, SLAB_KERNEL);
  77         if (vma) {
  78                 memset(vma, 0, sizeof(*vma));
  79                 vma->vm_mm = current->mm;
  80                 vma->vm_start = IA32_GDT_OFFSET;
  81                 vma->vm_end = vma->vm_start + PAGE_SIZE;
  82                 vma->vm_page_prot = PAGE_SHARED;
  83                 vma->vm_flags = VM_READ|VM_MAYREAD|VM_RESERVED;
  84                 vma->vm_ops = &ia32_shared_page_vm_ops;
  85                 down_write(&current->mm->mmap_sem);
  86                 {
  87                         insert_vm_struct(current->mm, vma);
  88                 }
  89                 up_write(&current->mm->mmap_sem);
  90         }
  91
  92         /*
  93          * Install LDT as anonymous memory.  This gives us all-zero segment descriptors
  94          * until a task modifies them via modify_ldt().
  95          */
  96         vma = kmem_cache_alloc(vm_area_cachep, SLAB_KERNEL);
  97         if (vma) {
  98                 memset(vma, 0, sizeof(*vma));
  99                 vma->vm_mm = current->mm;
 100                 vma->vm_start = IA32_LDT_OFFSET;
 101                 vma->vm_end = vma->vm_start + PAGE_ALIGN(IA32_LDT_ENTRIES*IA32_LDT_ENTRY_SIZE);
 102                 vma->vm_page_prot = PAGE_SHARED;
 103                 vma->vm_flags = VM_READ|VM_WRITE|VM_MAYREAD|VM_MAYWRITE;
 104                 down_write(&current->mm->mmap_sem);
 105                 {
 106                         insert_vm_struct(current->mm, vma);
 107                 }
 108                 up_write(&current->mm->mmap_sem);
 109         }
 110
 111         ia64_psr(regs)->ac = 0;         /* turn off alignment checking */
 112         regs->loadrs = 0;
 113         /*
 114          *  According to the ABI %edx points to an `atexit' handler.  Since we don't have
 115          *  one we'll set it to 0 and initialize all the other registers just to make
 116          *  things more deterministic, ala the i386 implementation.
 117          */
 118         regs->r8 = 0;   /* %eax */
 119         regs->r11 = 0;  /* %ebx */
 120         regs->r9 = 0;   /* %ecx */
 121         regs->r10 = 0;  /* %edx */
 122         regs->r13 = 0;  /* %ebp */
 123         regs->r14 = 0;  /* %esi */
 124         regs->r15 = 0;  /* %edi */
 125
 126         current->thread.eflag = IA32_EFLAG;
 127         current->thread.fsr = IA32_FSR_DEFAULT;
 128         current->thread.fcr = IA32_FCR_DEFAULT;
 129         current->thread.fir = 0;
 130         current->thread.fdr = 0;
 131
 132         /*
 133          * Setup GDTD.  Note: GDTD is the descrambled version of the pseudo-descriptor
 134          * format defined by Figure 3-11 "Pseudo-Descriptor Format" in the IA-32
 135          * architecture manual. Also note that the only fields that are not ignored are
 136          * `base', `limit', 'G', `P' (must be 1) and `S' (must be 0).
 137          */
 138         regs->r31 = IA32_SEG_UNSCRAMBLE(IA32_SEG_DESCRIPTOR(IA32_GDT_OFFSET, IA32_PAGE_SIZE - 1,
 139                                                             0, 0, 0, 1, 0, 0, 0));
 140         /* Setup the segment selectors */
 141         regs->r16 = (__USER_DS << 16) | __USER_DS; /* ES == DS, GS, FS are zero */
 142         regs->r17 = (__USER_DS << 16) | __USER_CS; /* SS, CS; ia32_load_state() sets TSS and LDT */
 143
 144         ia32_load_segment_descriptors(current);
 145         ia32_load_state(current);
 146 }
 147
 148 int
 149 ia32_setup_arg_pages (struct linux_binprm *bprm, int executable_stack)
 150 {
 151         unsigned long stack_base, grow;
 152         struct vm_area_struct *mpnt;
 153         struct mm_struct *mm = current->mm;
 154         int i;
 155
 156         stack_base = IA32_STACK_TOP - MAX_ARG_PAGES*PAGE_SIZE;
 157         mm->arg_start = bprm->p + stack_base;
 158
 159         bprm->p += stack_base;
 160         if (bprm->loader)
 161                 bprm->loader += stack_base;
 162         bprm->exec += stack_base;
 163
 164         mpnt = kmem_cache_alloc(vm_area_cachep, SLAB_KERNEL);
 165         if (!mpnt)
 166                 return -ENOMEM;
 167
 168         grow = (IA32_STACK_TOP - (PAGE_MASK & (unsigned long) bprm->p))
 169                 >> PAGE_SHIFT;
 170         if (security_vm_enough_memory(grow) ||
 171                 !vx_vmpages_avail(mm, grow)) {
 172                 kmem_cache_free(vm_area_cachep, mpnt);
 173                 return -ENOMEM;
 174         }
 175
 176         memset(mpnt, 0, sizeof(*mpnt));
 177
 178         down_write(&current->mm->mmap_sem);
 179         {
 180                 mpnt->vm_mm = current->mm;
 181                 mpnt->vm_start = PAGE_MASK & (unsigned long) bprm->p;
 182                 mpnt->vm_end = IA32_STACK_TOP;
 183                 if (executable_stack == EXSTACK_ENABLE_X)
 184                         mpnt->vm_flags = VM_STACK_FLAGS |  VM_EXEC;
 185                 else if (executable_stack == EXSTACK_DISABLE_X)
 186                         mpnt->vm_flags = VM_STACK_FLAGS & ~VM_EXEC;
 187                 else
 188                         mpnt->vm_flags = VM_STACK_FLAGS;
 189                 mpnt->vm_page_prot = (mpnt->vm_flags & VM_EXEC)?
 190                                         PAGE_COPY_EXEC: PAGE_COPY;
 191                 insert_vm_struct(current->mm, mpnt);
 192                 // current->mm->total_vm = (mpnt->vm_end - mpnt->vm_start) >> PAGE_SHIFT;
 193                 vx_vmpages_sub(current->mm, current->mm->total_vm -
 194                         ((mpnt->vm_end - mpnt->vm_start) >> PAGE_SHIFT));
 195         }
 196
 197         for (i = 0 ; i < MAX_ARG_PAGES ; i++) {
 198                 struct page *page = bprm->page[i];
 199                 if (page) {
 200                         bprm->page[i] = NULL;
 201                         install_arg_page(mpnt, page, stack_base);
 202                 }
 203                 stack_base += PAGE_SIZE;
 204         }
 205         up_write(&current->mm->mmap_sem);
 206
 207         /* Can't do it in ia64_elf32_init(). Needs to be done before calls to
 208            elf32_map() */
 209         current->thread.ppl = ia32_init_pp_list();
 210
 211         return 0;
 212 }
 213
 214 static void
 215 elf32_set_personality (void)
 216 {
 217         set_personality(PER_LINUX32);
 218         current->thread.map_base  = IA32_PAGE_OFFSET/3;
 219         current->thread.task_size = IA32_PAGE_OFFSET;   /* use what Linux/x86 uses... */
 220         set_fs(USER_DS);                                /* set addr limit for new TASK_SIZE */
 221 }
 222
 223 static unsigned long
 224 elf32_map (struct file *filep, unsigned long addr, struct elf_phdr *eppnt, int prot, int type, unsigned long unused)
 225 {
 226         unsigned long pgoff = (eppnt->p_vaddr) & ~IA32_PAGE_MASK;
 227
 228         return ia32_do_mmap(filep, (addr & IA32_PAGE_MASK), eppnt->p_filesz + pgoff, prot, type,
 229                             eppnt->p_offset - pgoff);
 230 }
 231
 232 #define cpu_uses_ia32el()       (local_cpu_data->family > 0x1f)
 233
 234 static int __init check_elf32_binfmt(void)
 235 {
 236         if (cpu_uses_ia32el()) {
 237                 printk("Please use IA-32 EL for executing IA-32 binaries\n");
 238                 return unregister_binfmt(&elf_format);
 239         }
 240         return 0;
 241 }
 242
 243 module_init(check_elf32_binfmt)