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 /* Ugly but avoids duplication */
  45 #include "../../../fs/binfmt_elf.c"
  46
  47 extern struct page *ia32_shared_page[];
  48 extern unsigned long *ia32_gdt;
  49
  50 struct page *
  51 ia32_install_shared_page (struct vm_area_struct *vma, unsigned long address, int *type)
  52 {
  53         struct page *pg = ia32_shared_page[smp_processor_id()];
  54         get_page(pg);
  55         if (type)
  56                 *type = VM_FAULT_MINOR;
  57         return pg;
  58 }
  59
  60 static struct vm_operations_struct ia32_shared_page_vm_ops = {
  61         .nopage = ia32_install_shared_page
  62 };
  63
  64 void
  65 ia64_elf32_init (struct pt_regs *regs)
  66 {
  67         struct vm_area_struct *vma;
  68
  69         /*
  70          * Map GDT below 4GB, where the processor can find it.  We need to map
  71          * it with privilege level 3 because the IVE uses non-privileged accesses to these
  72          * tables.  IA-32 segmentation is used to protect against IA-32 accesses to them.
  73          */
  74         vma = kmem_cache_alloc(vm_area_cachep, SLAB_KERNEL);
  75         if (vma) {
  76                 memset(vma, 0, sizeof(*vma));
  77                 vma->vm_mm = current->mm;
  78                 vma->vm_start = IA32_GDT_OFFSET;
  79                 vma->vm_end = vma->vm_start + PAGE_SIZE;
  80                 vma->vm_page_prot = PAGE_SHARED;
  81                 vma->vm_flags = VM_READ|VM_MAYREAD|VM_RESERVED;
  82                 vma->vm_ops = &ia32_shared_page_vm_ops;
  83                 down_write(&current->mm->mmap_sem);
  84                 {
  85                         insert_vm_struct(current->mm, vma);
  86                 }
  87                 up_write(&current->mm->mmap_sem);
  88         }
  89
  90         /*
  91          * Install LDT as anonymous memory.  This gives us all-zero segment descriptors
  92          * until a task modifies them via modify_ldt().
  93          */
  94         vma = kmem_cache_alloc(vm_area_cachep, SLAB_KERNEL);
  95         if (vma) {
  96                 memset(vma, 0, sizeof(*vma));
  97                 vma->vm_mm = current->mm;
  98                 vma->vm_start = IA32_LDT_OFFSET;
  99                 vma->vm_end = vma->vm_start + PAGE_ALIGN(IA32_LDT_ENTRIES*IA32_LDT_ENTRY_SIZE);
 100                 vma->vm_page_prot = PAGE_SHARED;
 101                 vma->vm_flags = VM_READ|VM_WRITE|VM_MAYREAD|VM_MAYWRITE;
 102                 down_write(&current->mm->mmap_sem);
 103                 {
 104                         insert_vm_struct(current->mm, vma);
 105                 }
 106                 up_write(&current->mm->mmap_sem);
 107         }
 108
 109         ia64_psr(regs)->ac = 0;         /* turn off alignment checking */
 110         regs->loadrs = 0;
 111         /*
 112          *  According to the ABI %edx points to an `atexit' handler.  Since we don't have
 113          *  one we'll set it to 0 and initialize all the other registers just to make
 114          *  things more deterministic, ala the i386 implementation.
 115          */
 116         regs->r8 = 0;   /* %eax */
 117         regs->r11 = 0;  /* %ebx */
 118         regs->r9 = 0;   /* %ecx */
 119         regs->r10 = 0;  /* %edx */
 120         regs->r13 = 0;  /* %ebp */
 121         regs->r14 = 0;  /* %esi */
 122         regs->r15 = 0;  /* %edi */
 123
 124         current->thread.eflag = IA32_EFLAG;
 125         current->thread.fsr = IA32_FSR_DEFAULT;
 126         current->thread.fcr = IA32_FCR_DEFAULT;
 127         current->thread.fir = 0;
 128         current->thread.fdr = 0;
 129
 130         /*
 131          * Setup GDTD.  Note: GDTD is the descrambled version of the pseudo-descriptor
 132          * format defined by Figure 3-11 "Pseudo-Descriptor Format" in the IA-32
 133          * architecture manual. Also note that the only fields that are not ignored are
 134          * `base', `limit', 'G', `P' (must be 1) and `S' (must be 0).
 135          */
 136         regs->r31 = IA32_SEG_UNSCRAMBLE(IA32_SEG_DESCRIPTOR(IA32_GDT_OFFSET, IA32_PAGE_SIZE - 1,
 137                                                             0, 0, 0, 1, 0, 0, 0));
 138         /* Setup the segment selectors */
 139         regs->r16 = (__USER_DS << 16) | __USER_DS; /* ES == DS, GS, FS are zero */
 140         regs->r17 = (__USER_DS << 16) | __USER_CS; /* SS, CS; ia32_load_state() sets TSS and LDT */
 141
 142         ia32_load_segment_descriptors(current);
 143         ia32_load_state(current);
 144 }
 145
 146 int
 147 ia32_setup_arg_pages (struct linux_binprm *bprm, int executable_stack)
 148 {
 149         unsigned long stack_base, grow;
 150         struct vm_area_struct *mpnt;
 151         struct mm_struct *mm = current->mm;
 152         int i;
 153
 154         stack_base = IA32_STACK_TOP - MAX_ARG_PAGES*PAGE_SIZE;
 155         mm->arg_start = bprm->p + stack_base;
 156
 157         bprm->p += stack_base;
 158         if (bprm->loader)
 159                 bprm->loader += stack_base;
 160         bprm->exec += stack_base;
 161
 162         mpnt = kmem_cache_alloc(vm_area_cachep, SLAB_KERNEL);
 163         if (!mpnt)
 164                 return -ENOMEM;
 165
 166         grow = (IA32_STACK_TOP - (PAGE_MASK & (unsigned long) bprm->p))
 167                 >> PAGE_SHIFT;
 168         if (security_vm_enough_memory(grow) ||
 169                 !vx_vmpages_avail(mm, grow)) {
 170                 kmem_cache_free(vm_area_cachep, mpnt);
 171                 return -ENOMEM;
 172         }
 173
 174         memset(mpnt, 0, sizeof(*mpnt));
 175
 176         down_write(&current->mm->mmap_sem);
 177         {
 178                 mpnt->vm_mm = current->mm;
 179                 mpnt->vm_start = PAGE_MASK & (unsigned long) bprm->p;
 180                 mpnt->vm_end = IA32_STACK_TOP;
 181                 if (executable_stack == EXSTACK_ENABLE_X)
 182                         mpnt->vm_flags = VM_STACK_FLAGS |  VM_EXEC;
 183                 else if (executable_stack == EXSTACK_DISABLE_X)
 184                         mpnt->vm_flags = VM_STACK_FLAGS & ~VM_EXEC;
 185                 else
 186                         mpnt->vm_flags = VM_STACK_FLAGS;
 187                 mpnt->vm_page_prot = (mpnt->vm_flags & VM_EXEC)?
 188                                         PAGE_COPY_EXEC: PAGE_COPY;
 189                 insert_vm_struct(current->mm, mpnt);
 190                 // current->mm->total_vm = (mpnt->vm_end - mpnt->vm_start) >> PAGE_SHIFT;
 191                 vx_vmpages_sub(current->mm, current->mm->total_vm -
 192                         ((mpnt->vm_end - mpnt->vm_start) >> PAGE_SHIFT));
 193         }
 194
 195         for (i = 0 ; i < MAX_ARG_PAGES ; i++) {
 196                 struct page *page = bprm->page[i];
 197                 if (page) {
 198                         bprm->page[i] = NULL;
 199                         install_arg_page(mpnt, page, stack_base);
 200                 }
 201                 stack_base += PAGE_SIZE;
 202         }
 203         up_write(&current->mm->mmap_sem);
 204
 205         return 0;
 206 }
 207
 208 static void
 209 elf32_set_personality (void)
 210 {
 211         set_personality(PER_LINUX32);
 212         current->thread.map_base  = IA32_PAGE_OFFSET/3;
 213         current->thread.task_size = IA32_PAGE_OFFSET;   /* use what Linux/x86 uses... */
 214         current->thread.flags |= IA64_THREAD_XSTACK;    /* data must be executable */
 215         set_fs(USER_DS);                                /* set addr limit for new TASK_SIZE */
 216 }
 217
 218 static unsigned long
 219 elf32_map (struct file *filep, unsigned long addr, struct elf_phdr *eppnt, int prot, int type)
 220 {
 221         unsigned long pgoff = (eppnt->p_vaddr) & ~IA32_PAGE_MASK;
 222
 223         return ia32_do_mmap(filep, (addr & IA32_PAGE_MASK), eppnt->p_filesz + pgoff, prot, type,
 224                             eppnt->p_offset - pgoff);
 225 }
 226
 227 #define cpu_uses_ia32el()       (local_cpu_data->family > 0x1f)
 228
 229 static int __init check_elf32_binfmt(void)
 230 {
 231         if (cpu_uses_ia32el()) {
 232                 printk("Please use IA-32 EL for executing IA-32 binaries\n");
 233                 return unregister_binfmt(&elf_format);
 234         }
 235         return 0;
 236 }
 237
 238 module_init(check_elf32_binfmt)