arch/ia64/kernel/sys_ia64.c

   1 /*
   2  * This file contains various system calls that have different calling
   3  * conventions on different platforms.
   4  *
   5  * Copyright (C) 1999-2000, 2002-2003, 2005 Hewlett-Packard Co
   6  *      David Mosberger-Tang <davidm@hpl.hp.com>
   7  */
   8 #include <linux/config.h>
   9 #include <linux/errno.h>
  10 #include <linux/fs.h>
  11 #include <linux/mm.h>
  12 #include <linux/mman.h>
  13 #include <linux/sched.h>
  14 #include <linux/shm.h>
  15 #include <linux/file.h>         /* doh, must come after sched.h... */
  16 #include <linux/smp.h>
  17 #include <linux/smp_lock.h>
  18 #include <linux/syscalls.h>
  19 #include <linux/highuid.h>
  20 #include <linux/hugetlb.h>
  21
  22 #include <asm/shmparam.h>
  23 #include <asm/uaccess.h>
  24
  25 unsigned long
  26 arch_get_unmapped_area (struct file *filp, unsigned long addr, unsigned long len,
  27                         unsigned long pgoff, unsigned long flags)
  28 {
  29         long map_shared = (flags & MAP_SHARED);
  30         unsigned long start_addr, align_mask = PAGE_SIZE - 1;
  31         struct mm_struct *mm = current->mm;
  32         struct vm_area_struct *vma;
  33
  34         if (len > RGN_MAP_LIMIT)
  35                 return -ENOMEM;
  36
  37 #ifdef CONFIG_HUGETLB_PAGE
  38         if (REGION_NUMBER(addr) == REGION_HPAGE)
  39                 addr = 0;
  40 #endif
  41         if (!addr)
  42                 addr = mm->free_area_cache;
  43
  44         if (map_shared && (TASK_SIZE > 0xfffffffful))
  45                 /*
  46                  * For 64-bit tasks, align shared segments to 1MB to avoid potential
  47                  * performance penalty due to virtual aliasing (see ASDM).  For 32-bit
  48                  * tasks, we prefer to avoid exhausting the address space too quickly by
  49                  * limiting alignment to a single page.
  50                  */
  51                 align_mask = SHMLBA - 1;
  52
  53   full_search:
  54         start_addr = addr = (addr + align_mask) & ~align_mask;
  55
  56         for (vma = find_vma(mm, addr); ; vma = vma->vm_next) {
  57                 /* At this point:  (!vma || addr < vma->vm_end). */
  58                 if (TASK_SIZE - len < addr || RGN_MAP_LIMIT - len < REGION_OFFSET(addr)) {
  59                         if (start_addr != TASK_UNMAPPED_BASE) {
  60                                 /* Start a new search --- just in case we missed some holes.  */
  61                                 addr = TASK_UNMAPPED_BASE;
  62                                 goto full_search;
  63                         }
  64                         return -ENOMEM;
  65                 }
  66                 if (!vma || addr + len <= vma->vm_start) {
  67                         /* Remember the address where we stopped this search:  */
  68                         mm->free_area_cache = addr + len;
  69                         return addr;
  70                 }
  71                 addr = (vma->vm_end + align_mask) & ~align_mask;
  72         }
  73 }
  74
  75 asmlinkage long
  76 ia64_getpriority (int which, int who)
  77 {
  78         long prio;
  79
  80         prio = sys_getpriority(which, who);
  81         if (prio >= 0) {
  82                 force_successful_syscall_return();
  83                 prio = 20 - prio;
  84         }
  85         return prio;
  86 }
  87
  88 /* XXX obsolete, but leave it here until the old libc is gone... */
  89 asmlinkage unsigned long
  90 sys_getpagesize (void)
  91 {
  92         return PAGE_SIZE;
  93 }
  94
  95 asmlinkage unsigned long
  96 ia64_brk (unsigned long brk)
  97 {
  98         unsigned long rlim, retval, newbrk, oldbrk;
  99         struct mm_struct *mm = current->mm;
 100
 101         /*
 102          * Most of this replicates the code in sys_brk() except for an additional safety
 103          * check and the clearing of r8.  However, we can't call sys_brk() because we need
 104          * to acquire the mmap_sem before we can do the test...
 105          */
 106         down_write(&mm->mmap_sem);
 107
 108         if (brk < mm->end_code)
 109                 goto out;
 110         newbrk = PAGE_ALIGN(brk);
 111         oldbrk = PAGE_ALIGN(mm->brk);
 112         if (oldbrk == newbrk)
 113                 goto set_brk;
 114
 115         /* Always allow shrinking brk. */
 116         if (brk <= mm->brk) {
 117                 if (!do_munmap(mm, newbrk, oldbrk-newbrk))
 118                         goto set_brk;
 119                 goto out;
 120         }
 121
 122         /* Check against unimplemented/unmapped addresses: */
 123         if ((newbrk - oldbrk) > RGN_MAP_LIMIT || REGION_OFFSET(newbrk) > RGN_MAP_LIMIT)
 124                 goto out;
 125
 126         /* Check against rlimit.. */
 127         rlim = current->signal->rlim[RLIMIT_DATA].rlim_cur;
 128         if (rlim < RLIM_INFINITY && brk - mm->start_data > rlim)
 129                 goto out;
 130
 131         /* Check against existing mmap mappings. */
 132         if (find_vma_intersection(mm, oldbrk, newbrk+PAGE_SIZE))
 133                 goto out;
 134
 135         /* Ok, looks good - let it rip. */
 136         if (do_brk(oldbrk, newbrk-oldbrk) != oldbrk)
 137                 goto out;
 138 set_brk:
 139         mm->brk = brk;
 140 out:
 141         retval = mm->brk;
 142         up_write(&mm->mmap_sem);
 143         force_successful_syscall_return();
 144         return retval;
 145 }
 146
 147 /*
 148  * On IA-64, we return the two file descriptors in ret0 and ret1 (r8
 149  * and r9) as this is faster than doing a copy_to_user().
 150  */
 151 asmlinkage long
 152 sys_pipe (void)
 153 {
 154         struct pt_regs *regs = ia64_task_regs(current);
 155         int fd[2];
 156         int retval;
 157
 158         retval = do_pipe(fd);
 159         if (retval)
 160                 goto out;
 161         retval = fd[0];
 162         regs->r9 = fd[1];
 163   out:
 164         return retval;
 165 }
 166
 167 static inline unsigned long
 168 do_mmap2 (unsigned long addr, unsigned long len, int prot, int flags, int fd, unsigned long pgoff)
 169 {
 170         unsigned long roff;
 171         struct file *file = NULL;
 172
 173         flags &= ~(MAP_EXECUTABLE | MAP_DENYWRITE);
 174         if (!(flags & MAP_ANONYMOUS)) {
 175                 file = fget(fd);
 176                 if (!file)
 177                         return -EBADF;
 178
 179                 if (!file->f_op || !file->f_op->mmap) {
 180                         addr = -ENODEV;
 181                         goto out;
 182                 }
 183         }
 184
 185         /*
 186          * A zero mmap always succeeds in Linux, independent of whether or not the
 187          * remaining arguments are valid.
 188          */
 189         if (len == 0)
 190                 goto out;
 191
 192         /* Careful about overflows.. */
 193         len = PAGE_ALIGN(len);
 194         if (!len || len > TASK_SIZE) {
 195                 addr = -EINVAL;
 196                 goto out;
 197         }
 198
 199         /*
 200          * Don't permit mappings into unmapped space, the virtual page table of a region,
 201          * or across a region boundary.  Note: RGN_MAP_LIMIT is equal to 2^n-PAGE_SIZE
 202          * (for some integer n <= 61) and len > 0.
 203          */
 204         roff = REGION_OFFSET(addr);
 205         if ((len > RGN_MAP_LIMIT) || (roff > (RGN_MAP_LIMIT - len))) {
 206                 addr = -EINVAL;
 207                 goto out;
 208         }
 209
 210         down_write(&current->mm->mmap_sem);
 211         addr = do_mmap_pgoff(file, addr, len, prot, flags, pgoff);
 212         up_write(&current->mm->mmap_sem);
 213
 214 out:    if (file)
 215                 fput(file);
 216         return addr;
 217 }
 218
 219 /*
 220  * mmap2() is like mmap() except that the offset is expressed in units
 221  * of PAGE_SIZE (instead of bytes).  This allows to mmap2() (pieces
 222  * of) files that are larger than the address space of the CPU.
 223  */
 224 asmlinkage unsigned long
 225 sys_mmap2 (unsigned long addr, unsigned long len, int prot, int flags, int fd, long pgoff)
 226 {
 227         addr = do_mmap2(addr, len, prot, flags, fd, pgoff);
 228         if (!IS_ERR((void *) addr))
 229                 force_successful_syscall_return();
 230         return addr;
 231 }
 232
 233 asmlinkage unsigned long
 234 sys_mmap (unsigned long addr, unsigned long len, int prot, int flags, int fd, long off)
 235 {
 236         if (offset_in_page(off) != 0)
 237                 return -EINVAL;
 238
 239         addr = do_mmap2(addr, len, prot, flags, fd, off >> PAGE_SHIFT);
 240         if (!IS_ERR((void *) addr))
 241                 force_successful_syscall_return();
 242         return addr;
 243 }
 244
 245 asmlinkage unsigned long
 246 ia64_mremap (unsigned long addr, unsigned long old_len, unsigned long new_len, unsigned long flags,
 247              unsigned long new_addr)
 248 {
 249         extern unsigned long do_mremap (unsigned long addr,
 250                                         unsigned long old_len,
 251                                         unsigned long new_len,
 252                                         unsigned long flags,
 253                                         unsigned long new_addr);
 254
 255         down_write(&current->mm->mmap_sem);
 256         {
 257                 addr = do_mremap(addr, old_len, new_len, flags, new_addr);
 258         }
 259         up_write(&current->mm->mmap_sem);
 260
 261         if (IS_ERR((void *) addr))
 262                 return addr;
 263
 264         force_successful_syscall_return();
 265         return addr;
 266 }
 267
 268 #ifndef CONFIG_PCI
 269
 270 asmlinkage long
 271 sys_pciconfig_read (unsigned long bus, unsigned long dfn, unsigned long off, unsigned long len,
 272                     void *buf)
 273 {
 274         return -ENOSYS;
 275 }
 276
 277 asmlinkage long
 278 sys_pciconfig_write (unsigned long bus, unsigned long dfn, unsigned long off, unsigned long len,
 279                      void *buf)
 280 {
 281         return -ENOSYS;
 282 }
 283
 284 #endif /* CONFIG_PCI */