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 #define CONFIG_BINFMT_ELF32
  25
  26 /* Override some function names */
  27 #undef start_thread
  28 #define start_thread                    ia32_start_thread
  29 #define elf_format                      elf32_format
  30 #define init_elf_binfmt                 init_elf32_binfmt
  31 #define exit_elf_binfmt                 exit_elf32_binfmt
  32
  33 #undef CONFIG_BINFMT_ELF
  34 #ifdef CONFIG_BINFMT_ELF32
  35 # define CONFIG_BINFMT_ELF              CONFIG_BINFMT_ELF32
  36 #endif
  37
  38 #undef CONFIG_BINFMT_ELF_MODULE
  39 #ifdef CONFIG_BINFMT_ELF32_MODULE
  40 # define CONFIG_BINFMT_ELF_MODULE       CONFIG_BINFMT_ELF32_MODULE
  41 #endif
  42
  43 #undef CLOCKS_PER_SEC
  44 #define CLOCKS_PER_SEC  IA32_CLOCKS_PER_SEC
  45
  46 extern void ia64_elf32_init (struct pt_regs *regs);
  47
  48 static void elf32_set_personality (void);
  49
  50 #define setup_arg_pages(bprm)           ia32_setup_arg_pages(bprm)
  51 #define elf_map                         elf32_map
  52
  53 #undef SET_PERSONALITY
  54 #define SET_PERSONALITY(ex, ibcs2)      elf32_set_personality()
  55
  56 /* Ugly but avoids duplication */
  57 #include "../../../fs/binfmt_elf.c"
  58
  59 extern struct page *ia32_shared_page[];
  60 extern unsigned long *ia32_gdt;
  61
  62 struct page *
  63 ia32_install_shared_page (struct vm_area_struct *vma, unsigned long address, int no_share)
  64 {
  65         struct page *pg = ia32_shared_page[(address - vma->vm_start)/PAGE_SIZE];
  66
  67         get_page(pg);
  68         return pg;
  69 }
  70
  71 static struct vm_operations_struct ia32_shared_page_vm_ops = {
  72         .nopage =ia32_install_shared_page
  73 };
  74
  75 void
  76 ia64_elf32_init (struct pt_regs *regs)
  77 {
  78         struct vm_area_struct *vma;
  79
  80         /*
  81          * Map GDT and TSS below 4GB, where the processor can find them.  We need to map
  82          * it with privilege level 3 because the IVE uses non-privileged accesses to these
  83          * tables.  IA-32 segmentation is used to protect against IA-32 accesses to them.
  84          */
  85         vma = kmem_cache_alloc(vm_area_cachep, SLAB_KERNEL);
  86         if (vma) {
  87                 vma->vm_mm = current->mm;
  88                 vma->vm_start = IA32_GDT_OFFSET;
  89                 vma->vm_end = vma->vm_start + max(PAGE_SIZE, 2*IA32_PAGE_SIZE);
  90                 vma->vm_page_prot = PAGE_SHARED;
  91                 vma->vm_flags = VM_READ|VM_MAYREAD;
  92                 vma->vm_ops = &ia32_shared_page_vm_ops;
  93                 vma->vm_pgoff = 0;
  94                 vma->vm_file = NULL;
  95                 vma->vm_private_data = NULL;
  96                 down_write(&current->mm->mmap_sem);
  97                 {
  98                         insert_vm_struct(current->mm, vma);
  99                 }
 100                 up_write(&current->mm->mmap_sem);
 101         }
 102
 103         /*
 104          * Install LDT as anonymous memory.  This gives us all-zero segment descriptors
 105          * until a task modifies them via modify_ldt().
 106          */
 107         vma = kmem_cache_alloc(vm_area_cachep, SLAB_KERNEL);
 108         if (vma) {
 109                 vma->vm_mm = current->mm;
 110                 vma->vm_start = IA32_LDT_OFFSET;
 111                 vma->vm_end = vma->vm_start + PAGE_ALIGN(IA32_LDT_ENTRIES*IA32_LDT_ENTRY_SIZE);
 112                 vma->vm_page_prot = PAGE_SHARED;
 113                 vma->vm_flags = VM_READ|VM_WRITE|VM_MAYREAD|VM_MAYWRITE;
 114                 vma->vm_ops = NULL;
 115                 vma->vm_pgoff = 0;
 116                 vma->vm_file = NULL;
 117                 vma->vm_private_data = NULL;
 118                 down_write(&current->mm->mmap_sem);
 119                 {
 120                         insert_vm_struct(current->mm, vma);
 121                 }
 122                 up_write(&current->mm->mmap_sem);
 123         }
 124
 125         ia64_psr(regs)->ac = 0;         /* turn off alignment checking */
 126         regs->loadrs = 0;
 127         /*
 128          *  According to the ABI %edx points to an `atexit' handler.  Since we don't have
 129          *  one we'll set it to 0 and initialize all the other registers just to make
 130          *  things more deterministic, ala the i386 implementation.
 131          */
 132         regs->r8 = 0;   /* %eax */
 133         regs->r11 = 0;  /* %ebx */
 134         regs->r9 = 0;   /* %ecx */
 135         regs->r10 = 0;  /* %edx */
 136         regs->r13 = 0;  /* %ebp */
 137         regs->r14 = 0;  /* %esi */
 138         regs->r15 = 0;  /* %edi */
 139
 140         current->thread.eflag = IA32_EFLAG;
 141         current->thread.fsr = IA32_FSR_DEFAULT;
 142         current->thread.fcr = IA32_FCR_DEFAULT;
 143         current->thread.fir = 0;
 144         current->thread.fdr = 0;
 145
 146         /*
 147          * Setup GDTD.  Note: GDTD is the descrambled version of the pseudo-descriptor
 148          * format defined by Figure 3-11 "Pseudo-Descriptor Format" in the IA-32
 149          * architecture manual. Also note that the only fields that are not ignored are
 150          * `base', `limit', 'G', `P' (must be 1) and `S' (must be 0).
 151          */
 152         regs->r31 = IA32_SEG_UNSCRAMBLE(IA32_SEG_DESCRIPTOR(IA32_GDT_OFFSET, IA32_PAGE_SIZE - 1,
 153                                                             0, 0, 0, 1, 0, 0, 0));
 154         /* Setup the segment selectors */
 155         regs->r16 = (__USER_DS << 16) | __USER_DS; /* ES == DS, GS, FS are zero */
 156         regs->r17 = (__USER_DS << 16) | __USER_CS; /* SS, CS; ia32_load_state() sets TSS and LDT */
 157
 158         ia32_load_segment_descriptors(current);
 159         ia32_load_state(current);
 160 }
 161
 162 int
 163 ia32_setup_arg_pages (struct linux_binprm *bprm)
 164 {
 165         unsigned long stack_base;
 166         struct vm_area_struct *mpnt;
 167         struct mm_struct *mm = current->mm;
 168         int i;
 169
 170         stack_base = IA32_STACK_TOP - MAX_ARG_PAGES*PAGE_SIZE;
 171         mm->arg_start = bprm->p + stack_base;
 172
 173         bprm->p += stack_base;
 174         if (bprm->loader)
 175                 bprm->loader += stack_base;
 176         bprm->exec += stack_base;
 177
 178         mpnt = kmem_cache_alloc(vm_area_cachep, SLAB_KERNEL);
 179         if (!mpnt)
 180                 return -ENOMEM;
 181
 182         if (security_vm_enough_memory((IA32_STACK_TOP - (PAGE_MASK & (unsigned long) bprm->p))>>PAGE_SHIFT)) {
 183                 kmem_cache_free(vm_area_cachep, mpnt);
 184                 return -ENOMEM;
 185         }
 186
 187         down_write(&current->mm->mmap_sem);
 188         {
 189                 mpnt->vm_mm = current->mm;
 190                 mpnt->vm_start = PAGE_MASK & (unsigned long) bprm->p;
 191                 mpnt->vm_end = IA32_STACK_TOP;
 192                 mpnt->vm_page_prot = PAGE_COPY;
 193                 mpnt->vm_flags = VM_STACK_FLAGS;
 194                 mpnt->vm_ops = NULL;
 195                 mpnt->vm_pgoff = 0;
 196                 mpnt->vm_file = NULL;
 197                 mpnt->vm_private_data = 0;
 198                 insert_vm_struct(current->mm, mpnt);
 199                 current->mm->total_vm = (mpnt->vm_end - mpnt->vm_start) >> PAGE_SHIFT;
 200         }
 201
 202         for (i = 0 ; i < MAX_ARG_PAGES ; i++) {
 203                 struct page *page = bprm->page[i];
 204                 if (page) {
 205                         bprm->page[i] = NULL;
 206                         put_dirty_page(current, page, stack_base, PAGE_COPY);
 207                 }
 208                 stack_base += PAGE_SIZE;
 209         }
 210         up_write(&current->mm->mmap_sem);
 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         current->thread.flags |= IA64_THREAD_XSTACK;    /* data must be executable */
 222         set_fs(USER_DS);                                /* set addr limit for new TASK_SIZE */
 223 }
 224
 225 static unsigned long
 226 elf32_map (struct file *filep, unsigned long addr, struct elf_phdr *eppnt, int prot, int type)
 227 {
 228         unsigned long pgoff = (eppnt->p_vaddr) & ~IA32_PAGE_MASK;
 229
 230         return ia32_do_mmap(filep, (addr & IA32_PAGE_MASK), eppnt->p_filesz + pgoff, prot, type,
 231                             eppnt->p_offset - pgoff);
 232 }