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 #include "elfcore32.h"
  21
  22 #define CONFIG_BINFMT_ELF32
  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 CONFIG_BINFMT_ELF
  32 #ifdef CONFIG_BINFMT_ELF32
  33 # define CONFIG_BINFMT_ELF              CONFIG_BINFMT_ELF32
  34 #endif
  35
  36 #undef CONFIG_BINFMT_ELF_MODULE
  37 #ifdef CONFIG_BINFMT_ELF32_MODULE
  38 # define CONFIG_BINFMT_ELF_MODULE       CONFIG_BINFMT_ELF32_MODULE
  39 #endif
  40
  41 #undef CLOCKS_PER_SEC
  42 #define CLOCKS_PER_SEC  IA32_CLOCKS_PER_SEC
  43
  44 extern void ia64_elf32_init (struct pt_regs *regs);
  45 extern void put_dirty_page (struct task_struct * tsk, struct page *page, unsigned long address);
  46
  47 static void elf32_set_personality (void);
  48
  49 #define ELF_PLAT_INIT(_r, load_addr)    ia64_elf32_init(_r)
  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                         if (insert_vm_struct(current->mm, vma)) {
  99                                 kmem_cache_free(vm_area_cachep, vma);
 100                                 up_write(&current->mm->mmap_sem);
 101                                 return;
 102                         }
 103                 }
 104                 up_write(&current->mm->mmap_sem);
 105         }
 106
 107         /*
 108          * Install LDT as anonymous memory.  This gives us all-zero segment descriptors
 109          * until a task modifies them via modify_ldt().
 110          */
 111         vma = kmem_cache_alloc(vm_area_cachep, SLAB_KERNEL);
 112         if (vma) {
 113                 vma->vm_mm = current->mm;
 114                 vma->vm_start = IA32_LDT_OFFSET;
 115                 vma->vm_end = vma->vm_start + PAGE_ALIGN(IA32_LDT_ENTRIES*IA32_LDT_ENTRY_SIZE);
 116                 vma->vm_page_prot = PAGE_SHARED;
 117                 vma->vm_flags = VM_READ|VM_WRITE|VM_MAYREAD|VM_MAYWRITE;
 118                 vma->vm_ops = NULL;
 119                 vma->vm_pgoff = 0;
 120                 vma->vm_file = NULL;
 121                 vma->vm_private_data = NULL;
 122                 down_write(&current->mm->mmap_sem);
 123                 {
 124                         if (insert_vm_struct(current->mm, vma)) {
 125                                 kmem_cache_free(vm_area_cachep, vma);
 126                                 up_write(&current->mm->mmap_sem);
 127                                 return;
 128                         }
 129                 }
 130                 up_write(&current->mm->mmap_sem);
 131         }
 132
 133         ia64_psr(regs)->ac = 0;         /* turn off alignment checking */
 134         regs->loadrs = 0;
 135         /*
 136          *  According to the ABI %edx points to an `atexit' handler.  Since we don't have
 137          *  one we'll set it to 0 and initialize all the other registers just to make
 138          *  things more deterministic, ala the i386 implementation.
 139          */
 140         regs->r8 = 0;   /* %eax */
 141         regs->r11 = 0;  /* %ebx */
 142         regs->r9 = 0;   /* %ecx */
 143         regs->r10 = 0;  /* %edx */
 144         regs->r13 = 0;  /* %ebp */
 145         regs->r14 = 0;  /* %esi */
 146         regs->r15 = 0;  /* %edi */
 147
 148         current->thread.eflag = IA32_EFLAG;
 149         current->thread.fsr = IA32_FSR_DEFAULT;
 150         current->thread.fcr = IA32_FCR_DEFAULT;
 151         current->thread.fir = 0;
 152         current->thread.fdr = 0;
 153
 154         /*
 155          * Setup GDTD.  Note: GDTD is the descrambled version of the pseudo-descriptor
 156          * format defined by Figure 3-11 "Pseudo-Descriptor Format" in the IA-32
 157          * architecture manual. Also note that the only fields that are not ignored are
 158          * `base', `limit', 'G', `P' (must be 1) and `S' (must be 0).
 159          */
 160         regs->r31 = IA32_SEG_UNSCRAMBLE(IA32_SEG_DESCRIPTOR(IA32_GDT_OFFSET, IA32_PAGE_SIZE - 1,
 161                                                             0, 0, 0, 1, 0, 0, 0));
 162         /* Setup the segment selectors */
 163         regs->r16 = (__USER_DS << 16) | __USER_DS; /* ES == DS, GS, FS are zero */
 164         regs->r17 = (__USER_DS << 16) | __USER_CS; /* SS, CS; ia32_load_state() sets TSS and LDT */
 165
 166         ia32_load_segment_descriptors(current);
 167         ia32_load_state(current);
 168 }
 169
 170 int
 171 ia32_setup_arg_pages (struct linux_binprm *bprm)
 172 {
 173         unsigned long stack_base;
 174         struct vm_area_struct *mpnt;
 175         int i, ret;
 176
 177         stack_base = IA32_STACK_TOP - MAX_ARG_PAGES*PAGE_SIZE;
 178
 179         bprm->p += stack_base;
 180         if (bprm->loader)
 181                 bprm->loader += stack_base;
 182         bprm->exec += stack_base;
 183
 184         mpnt = kmem_cache_alloc(vm_area_cachep, SLAB_KERNEL);
 185         if (!mpnt)
 186                 return -ENOMEM;
 187
 188         down_write(&current->mm->mmap_sem);
 189         {
 190                 mpnt->vm_mm = current->mm;
 191                 mpnt->vm_start = PAGE_MASK & (unsigned long) bprm->p;
 192                 mpnt->vm_end = IA32_STACK_TOP;
 193                 mpnt->vm_page_prot = PAGE_COPY;
 194                 mpnt->vm_flags = VM_STACK_FLAGS;
 195                 mpnt->vm_ops = NULL;
 196                 mpnt->vm_pgoff = 0;
 197                 mpnt->vm_file = NULL;
 198                 mpnt->vm_private_data = 0;
 199                 if ((ret = insert_vm_struct(current->mm, mpnt))) {
 200                         up_write(&current->mm->mmap_sem);
 201                         kmem_cache_free(vm_area_cachep, mpnt);
 202                         return ret;
 203                 }
 204                 current->mm->total_vm = (mpnt->vm_end - mpnt->vm_start) >> PAGE_SHIFT;
 205         }
 206
 207         for (i = 0 ; i < MAX_ARG_PAGES ; i++) {
 208                 struct page *page = bprm->page[i];
 209                 if (page) {
 210                         bprm->page[i] = NULL;
 211                         put_dirty_page(current, page, stack_base);
 212                 }
 213                 stack_base += PAGE_SIZE;
 214         }
 215         up_write(&current->mm->mmap_sem);
 216
 217         return 0;
 218 }
 219
 220 static void
 221 elf32_set_personality (void)
 222 {
 223         set_personality(PER_LINUX32);
 224         current->thread.map_base  = IA32_PAGE_OFFSET/3;
 225         current->thread.task_size = IA32_PAGE_OFFSET;   /* use what Linux/x86 uses... */
 226         current->thread.flags |= IA64_THREAD_XSTACK;    /* data must be executable */
 227         set_fs(USER_DS);                                /* set addr limit for new TASK_SIZE */
 228 }
 229
 230 static unsigned long
 231 elf32_map (struct file *filep, unsigned long addr, struct elf_phdr *eppnt, int prot, int type)
 232 {
 233         unsigned long pgoff = (eppnt->p_vaddr) & ~IA32_PAGE_MASK;
 234
 235         return ia32_do_mmap(filep, (addr & IA32_PAGE_MASK), eppnt->p_filesz + pgoff, prot, type,
 236                             eppnt->p_offset - pgoff);
 237 }