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
  16 #include <asm/param.h>
  17 #include <asm/signal.h>
  18 #include <asm/ia32.h>
  19
  20 #define CONFIG_BINFMT_ELF32
  21
  22 /* Override some function names */
  23 #undef start_thread
  24 #define start_thread                    ia32_start_thread
  25 #define elf_format                      elf32_format
  26 #define init_elf_binfmt                 init_elf32_binfmt
  27 #define exit_elf_binfmt                 exit_elf32_binfmt
  28
  29 #undef CONFIG_BINFMT_ELF
  30 #ifdef CONFIG_BINFMT_ELF32
  31 # define CONFIG_BINFMT_ELF              CONFIG_BINFMT_ELF32
  32 #endif
  33
  34 #undef CONFIG_BINFMT_ELF_MODULE
  35 #ifdef CONFIG_BINFMT_ELF32_MODULE
  36 # define CONFIG_BINFMT_ELF_MODULE       CONFIG_BINFMT_ELF32_MODULE
  37 #endif
  38
  39 #undef CLOCKS_PER_SEC
  40 #define CLOCKS_PER_SEC  IA32_CLOCKS_PER_SEC
  41
  42 extern void ia64_elf32_init (struct pt_regs *regs);
  43 extern void put_dirty_page (struct task_struct * tsk, struct page *page, unsigned long address);
  44
  45 static void elf32_set_personality (void);
  46
  47 #define ELF_PLAT_INIT(_r)               ia64_elf32_init(_r)
  48 #define setup_arg_pages(bprm)           ia32_setup_arg_pages(bprm)
  49 #define elf_map                         elf32_map
  50
  51 #undef SET_PERSONALITY
  52 #define SET_PERSONALITY(ex, ibcs2)      elf32_set_personality()
  53
  54 /* Ugly but avoids duplication */
  55 #include "../../../fs/binfmt_elf.c"
  56
  57 extern struct page *ia32_shared_page[];
  58 extern unsigned long *ia32_gdt;
  59
  60 struct page *
  61 ia32_install_shared_page (struct vm_area_struct *vma, unsigned long address, int no_share)
  62 {
  63         struct page *pg = ia32_shared_page[(address - vma->vm_start)/PAGE_SIZE];
  64
  65         get_page(pg);
  66         return pg;
  67 }
  68
  69 static struct vm_operations_struct ia32_shared_page_vm_ops = {
  70         nopage: ia32_install_shared_page
  71 };
  72
  73 void
  74 ia64_elf32_init (struct pt_regs *regs)
  75 {
  76         struct vm_area_struct *vma;
  77
  78         /*
  79          * Map GDT and TSS below 4GB, where the processor can find them.  We need to map
  80          * it with privilege level 3 because the IVE uses non-privileged accesses to these
  81          * tables.  IA-32 segmentation is used to protect against IA-32 accesses to them.
  82          */
  83         vma = kmem_cache_alloc(vm_area_cachep, SLAB_KERNEL);
  84         if (vma) {
  85                 vma->vm_mm = current->mm;
  86                 vma->vm_start = IA32_GDT_OFFSET;
  87                 vma->vm_end = vma->vm_start + max(PAGE_SIZE, 2*IA32_PAGE_SIZE);
  88                 vma->vm_page_prot = PAGE_SHARED;
  89                 vma->vm_flags = VM_READ|VM_MAYREAD;
  90                 vma->vm_ops = &ia32_shared_page_vm_ops;
  91                 vma->vm_pgoff = 0;
  92                 vma->vm_file = NULL;
  93                 vma->vm_private_data = NULL;
  94                 down_write(&current->mm->mmap_sem);
  95                 {
  96                         insert_vm_struct(current->mm, vma);
  97                 }
  98                 up_write(&current->mm->mmap_sem);
  99         }
 100
 101         /*
 102          * Install LDT as anonymous memory.  This gives us all-zero segment descriptors
 103          * until a task modifies them via modify_ldt().
 104          */
 105         vma = kmem_cache_alloc(vm_area_cachep, SLAB_KERNEL);
 106         if (vma) {
 107                 vma->vm_mm = current->mm;
 108                 vma->vm_start = IA32_LDT_OFFSET;
 109                 vma->vm_end = vma->vm_start + PAGE_ALIGN(IA32_LDT_ENTRIES*IA32_LDT_ENTRY_SIZE);
 110                 vma->vm_page_prot = PAGE_SHARED;
 111                 vma->vm_flags = VM_READ|VM_WRITE|VM_MAYREAD|VM_MAYWRITE;
 112                 vma->vm_ops = NULL;
 113                 vma->vm_pgoff = 0;
 114                 vma->vm_file = NULL;
 115                 vma->vm_private_data = NULL;
 116                 down_write(&current->mm->mmap_sem);
 117                 {
 118                         insert_vm_struct(current->mm, vma);
 119                 }
 120                 up_write(&current->mm->mmap_sem);
 121         }
 122
 123         ia64_psr(regs)->ac = 0;         /* turn off alignment checking */
 124         regs->loadrs = 0;
 125         /*
 126          *  According to the ABI %edx points to an `atexit' handler.  Since we don't have
 127          *  one we'll set it to 0 and initialize all the other registers just to make
 128          *  things more deterministic, ala the i386 implementation.
 129          */
 130         regs->r8 = 0;   /* %eax */
 131         regs->r11 = 0;  /* %ebx */
 132         regs->r9 = 0;   /* %ecx */
 133         regs->r10 = 0;  /* %edx */
 134         regs->r13 = 0;  /* %ebp */
 135         regs->r14 = 0;  /* %esi */
 136         regs->r15 = 0;  /* %edi */
 137
 138         current->thread.eflag = IA32_EFLAG;
 139         current->thread.fsr = IA32_FSR_DEFAULT;
 140         current->thread.fcr = IA32_FCR_DEFAULT;
 141         current->thread.fir = 0;
 142         current->thread.fdr = 0;
 143
 144         /*
 145          * Setup GDTD.  Note: GDTD is the descrambled version of the pseudo-descriptor
 146          * format defined by Figure 3-11 "Pseudo-Descriptor Format" in the IA-32
 147          * architecture manual. Also note that the only fields that are not ignored are
 148          * `base', `limit', 'G', `P' (must be 1) and `S' (must be 0).
 149          */
 150         regs->r31 = IA32_SEG_UNSCRAMBLE(IA32_SEG_DESCRIPTOR(IA32_GDT_OFFSET, IA32_PAGE_SIZE - 1,
 151                                                             0, 0, 0, 1, 0, 0, 0));
 152         /* Setup the segment selectors */
 153         regs->r16 = (__USER_DS << 16) | __USER_DS; /* ES == DS, GS, FS are zero */
 154         regs->r17 = (__USER_DS << 16) | __USER_CS; /* SS, CS; ia32_load_state() sets TSS and LDT */
 155
 156         ia32_load_segment_descriptors(current);
 157         ia32_load_state(current);
 158 }
 159
 160 int
 161 ia32_setup_arg_pages (struct linux_binprm *bprm)
 162 {
 163         unsigned long stack_base;
 164         struct vm_area_struct *mpnt;
 165         int i;
 166
 167         stack_base = IA32_STACK_TOP - MAX_ARG_PAGES*PAGE_SIZE;
 168
 169         bprm->p += stack_base;
 170         if (bprm->loader)
 171                 bprm->loader += stack_base;
 172         bprm->exec += stack_base;
 173
 174         mpnt = kmem_cache_alloc(vm_area_cachep, SLAB_KERNEL);
 175         if (!mpnt)
 176                 return -ENOMEM;
 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                 mpnt->vm_page_prot = PAGE_COPY;
 184                 mpnt->vm_flags = VM_STACK_FLAGS;
 185                 mpnt->vm_ops = NULL;
 186                 mpnt->vm_pgoff = 0;
 187                 mpnt->vm_file = NULL;
 188                 mpnt->vm_private_data = 0;
 189                 insert_vm_struct(current->mm, mpnt);
 190                 current->mm->total_vm = (mpnt->vm_end - mpnt->vm_start) >> PAGE_SHIFT;
 191         }
 192
 193         for (i = 0 ; i < MAX_ARG_PAGES ; i++) {
 194                 struct page *page = bprm->page[i];
 195                 if (page) {
 196                         bprm->page[i] = NULL;
 197                         put_dirty_page(current, page, stack_base);
 198                 }
 199                 stack_base += PAGE_SIZE;
 200         }
 201         up_write(&current->mm->mmap_sem);
 202
 203         return 0;
 204 }
 205
 206 static void
 207 elf32_set_personality (void)
 208 {
 209         set_personality(PER_LINUX32);
 210         current->thread.map_base  = IA32_PAGE_OFFSET/3;
 211         current->thread.task_size = IA32_PAGE_OFFSET;   /* use what Linux/x86 uses... */
 212         current->thread.flags |= IA64_THREAD_XSTACK;    /* data must be executable */
 213         set_fs(USER_DS);                                /* set addr limit for new TASK_SIZE */
 214 }
 215
 216 static unsigned long
 217 elf32_map (struct file *filep, unsigned long addr, struct elf_phdr *eppnt, int prot, int type)
 218 {
 219         unsigned long pgoff = (eppnt->p_vaddr) & ~IA32_PAGE_MASK;
 220
 221         return ia32_do_mmap(filep, (addr & IA32_PAGE_MASK), eppnt->p_filesz + pgoff, prot, type,
 222                             eppnt->p_offset - pgoff);
 223 }