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