root/arch/parisc/kernel/sys_parisc.c

DEFINITIONS

1. get_offset
2. shared_align_offset
3. COLOR_ALIGN
4. mmap_upper_limit
5. arch_get_unmapped_area
6. arch_get_unmapped_area_topdown
7. mmap_is_legacy
8. mmap_rnd
9. arch_mmap_rnd
10. mmap_legacy_base
11. arch_pick_mmap_layout
12. sys_mmap2
13. sys_mmap
14. parisc_truncate64
15. parisc_ftruncate64
16. sys_truncate64
17. sys_ftruncate64
18. sys_fcntl64
19. parisc_truncate64
20. parisc_ftruncate64
21. parisc_pread64
22. parisc_pwrite64
23. parisc_readahead
24. parisc_fadvise64_64
25. parisc_sync_file_range
26. parisc_fallocate
27. parisc_personality

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 
   3 /*
   4  *    PARISC specific syscalls
   5  *
   6  *    Copyright (C) 1999-2003 Matthew Wilcox <willy at parisc-linux.org>
   7  *    Copyright (C) 2000-2003 Paul Bame <bame at parisc-linux.org>
   8  *    Copyright (C) 2001 Thomas Bogendoerfer <tsbogend at parisc-linux.org>
   9  *    Copyright (C) 1999-2014 Helge Deller <deller@gmx.de>
  10  */
  11 
  12 #include <linux/uaccess.h>
  13 #include <asm/elf.h>
  14 #include <linux/file.h>
  15 #include <linux/fs.h>
  16 #include <linux/linkage.h>
  17 #include <linux/mm.h>
  18 #include <linux/mman.h>
  19 #include <linux/sched/signal.h>
  20 #include <linux/sched/mm.h>
  21 #include <linux/shm.h>
  22 #include <linux/syscalls.h>
  23 #include <linux/utsname.h>
  24 #include <linux/personality.h>
  25 #include <linux/random.h>
  26 
  27 /* we construct an artificial offset for the mapping based on the physical
  28  * address of the kernel mapping variable */
  29 #define GET_LAST_MMAP(filp)             \
  30         (filp ? ((unsigned long) filp->f_mapping) >> 8 : 0UL)
  31 #define SET_LAST_MMAP(filp, val)        \
  32          { /* nothing */ }
  33 
  34 static int get_offset(unsigned int last_mmap)
  35 {
  36         return (last_mmap & (SHM_COLOUR-1)) >> PAGE_SHIFT;
  37 }
  38 
  39 static unsigned long shared_align_offset(unsigned int last_mmap,
  40                                          unsigned long pgoff)
  41 {
  42         return (get_offset(last_mmap) + pgoff) << PAGE_SHIFT;
  43 }
  44 
  45 static inline unsigned long COLOR_ALIGN(unsigned long addr,
  46                          unsigned int last_mmap, unsigned long pgoff)
  47 {
  48         unsigned long base = (addr+SHM_COLOUR-1) & ~(SHM_COLOUR-1);
  49         unsigned long off  = (SHM_COLOUR-1) &
  50                 (shared_align_offset(last_mmap, pgoff) << PAGE_SHIFT);
  51 
  52         return base + off;
  53 }
  54 
  55 /*
  56  * Top of mmap area (just below the process stack).
  57  */
  58 
  59 /*
  60  * When called from arch_get_unmapped_area(), rlim_stack will be NULL,
  61  * indicating that "current" should be used instead of a passed-in
  62  * value from the exec bprm as done with arch_pick_mmap_layout().
  63  */
  64 static unsigned long mmap_upper_limit(struct rlimit *rlim_stack)
  65 {
  66         unsigned long stack_base;
  67 
  68         /* Limit stack size - see setup_arg_pages() in fs/exec.c */
  69         stack_base = rlim_stack ? rlim_stack->rlim_max
  70                                 : rlimit_max(RLIMIT_STACK);
  71         if (stack_base > STACK_SIZE_MAX)
  72                 stack_base = STACK_SIZE_MAX;
  73 
  74         /* Add space for stack randomization. */
  75         if (current->flags & PF_RANDOMIZE)
  76                 stack_base += (STACK_RND_MASK << PAGE_SHIFT);
  77 
  78         return PAGE_ALIGN(STACK_TOP - stack_base);
  79 }
  80 
  81 
  82 unsigned long arch_get_unmapped_area(struct file *filp, unsigned long addr,
  83                 unsigned long len, unsigned long pgoff, unsigned long flags)
  84 {
  85         struct mm_struct *mm = current->mm;
  86         struct vm_area_struct *vma, *prev;
  87         unsigned long task_size = TASK_SIZE;
  88         int do_color_align, last_mmap;
  89         struct vm_unmapped_area_info info;
  90 
  91         if (len > task_size)
  92                 return -ENOMEM;
  93 
  94         do_color_align = 0;
  95         if (filp || (flags & MAP_SHARED))
  96                 do_color_align = 1;
  97         last_mmap = GET_LAST_MMAP(filp);
  98 
  99         if (flags & MAP_FIXED) {
 100                 if ((flags & MAP_SHARED) && last_mmap &&
 101                     (addr - shared_align_offset(last_mmap, pgoff))
 102                                 & (SHM_COLOUR - 1))
 103                         return -EINVAL;
 104                 goto found_addr;
 105         }
 106 
 107         if (addr) {
 108                 if (do_color_align && last_mmap)
 109                         addr = COLOR_ALIGN(addr, last_mmap, pgoff);
 110                 else
 111                         addr = PAGE_ALIGN(addr);
 112 
 113                 vma = find_vma_prev(mm, addr, &prev);
 114                 if (task_size - len >= addr &&
 115                     (!vma || addr + len <= vm_start_gap(vma)) &&
 116                     (!prev || addr >= vm_end_gap(prev)))
 117                         goto found_addr;
 118         }
 119 
 120         info.flags = 0;
 121         info.length = len;
 122         info.low_limit = mm->mmap_legacy_base;
 123         info.high_limit = mmap_upper_limit(NULL);
 124         info.align_mask = last_mmap ? (PAGE_MASK & (SHM_COLOUR - 1)) : 0;
 125         info.align_offset = shared_align_offset(last_mmap, pgoff);
 126         addr = vm_unmapped_area(&info);
 127 
 128 found_addr:
 129         if (do_color_align && !last_mmap && !(addr & ~PAGE_MASK))
 130                 SET_LAST_MMAP(filp, addr - (pgoff << PAGE_SHIFT));
 131 
 132         return addr;
 133 }
 134 
 135 unsigned long
 136 arch_get_unmapped_area_topdown(struct file *filp, const unsigned long addr0,
 137                           const unsigned long len, const unsigned long pgoff,
 138                           const unsigned long flags)
 139 {
 140         struct vm_area_struct *vma, *prev;
 141         struct mm_struct *mm = current->mm;
 142         unsigned long addr = addr0;
 143         int do_color_align, last_mmap;
 144         struct vm_unmapped_area_info info;
 145 
 146         /* requested length too big for entire address space */
 147         if (len > TASK_SIZE)
 148                 return -ENOMEM;
 149 
 150         do_color_align = 0;
 151         if (filp || (flags & MAP_SHARED))
 152                 do_color_align = 1;
 153         last_mmap = GET_LAST_MMAP(filp);
 154 
 155         if (flags & MAP_FIXED) {
 156                 if ((flags & MAP_SHARED) && last_mmap &&
 157                     (addr - shared_align_offset(last_mmap, pgoff))
 158                         & (SHM_COLOUR - 1))
 159                         return -EINVAL;
 160                 goto found_addr;
 161         }
 162 
 163         /* requesting a specific address */
 164         if (addr) {
 165                 if (do_color_align && last_mmap)
 166                         addr = COLOR_ALIGN(addr, last_mmap, pgoff);
 167                 else
 168                         addr = PAGE_ALIGN(addr);
 169 
 170                 vma = find_vma_prev(mm, addr, &prev);
 171                 if (TASK_SIZE - len >= addr &&
 172                     (!vma || addr + len <= vm_start_gap(vma)) &&
 173                     (!prev || addr >= vm_end_gap(prev)))
 174                         goto found_addr;
 175         }
 176 
 177         info.flags = VM_UNMAPPED_AREA_TOPDOWN;
 178         info.length = len;
 179         info.low_limit = PAGE_SIZE;
 180         info.high_limit = mm->mmap_base;
 181         info.align_mask = last_mmap ? (PAGE_MASK & (SHM_COLOUR - 1)) : 0;
 182         info.align_offset = shared_align_offset(last_mmap, pgoff);
 183         addr = vm_unmapped_area(&info);
 184         if (!(addr & ~PAGE_MASK))
 185                 goto found_addr;
 186         VM_BUG_ON(addr != -ENOMEM);
 187 
 188         /*
 189          * A failed mmap() very likely causes application failure,
 190          * so fall back to the bottom-up function here. This scenario
 191          * can happen with large stack limits and large mmap()
 192          * allocations.
 193          */
 194         return arch_get_unmapped_area(filp, addr0, len, pgoff, flags);
 195 
 196 found_addr:
 197         if (do_color_align && !last_mmap && !(addr & ~PAGE_MASK))
 198                 SET_LAST_MMAP(filp, addr - (pgoff << PAGE_SHIFT));
 199 
 200         return addr;
 201 }
 202 
 203 static int mmap_is_legacy(void)
 204 {
 205         if (current->personality & ADDR_COMPAT_LAYOUT)
 206                 return 1;
 207 
 208         /* parisc stack always grows up - so a unlimited stack should
 209          * not be an indicator to use the legacy memory layout.
 210          * if (rlimit(RLIMIT_STACK) == RLIM_INFINITY)
 211          *      return 1;
 212          */
 213 
 214         return sysctl_legacy_va_layout;
 215 }
 216 
 217 static unsigned long mmap_rnd(void)
 218 {
 219         unsigned long rnd = 0;
 220 
 221         if (current->flags & PF_RANDOMIZE)
 222                 rnd = get_random_int() & MMAP_RND_MASK;
 223 
 224         return rnd << PAGE_SHIFT;
 225 }
 226 
 227 unsigned long arch_mmap_rnd(void)
 228 {
 229         return (get_random_int() & MMAP_RND_MASK) << PAGE_SHIFT;
 230 }
 231 
 232 static unsigned long mmap_legacy_base(void)
 233 {
 234         return TASK_UNMAPPED_BASE + mmap_rnd();
 235 }
 236 
 237 /*
 238  * This function, called very early during the creation of a new
 239  * process VM image, sets up which VM layout function to use:
 240  */
 241 void arch_pick_mmap_layout(struct mm_struct *mm, struct rlimit *rlim_stack)
 242 {
 243         mm->mmap_legacy_base = mmap_legacy_base();
 244         mm->mmap_base = mmap_upper_limit(rlim_stack);
 245 
 246         if (mmap_is_legacy()) {
 247                 mm->mmap_base = mm->mmap_legacy_base;
 248                 mm->get_unmapped_area = arch_get_unmapped_area;
 249         } else {
 250                 mm->get_unmapped_area = arch_get_unmapped_area_topdown;
 251         }
 252 }
 253 
 254 
 255 asmlinkage unsigned long sys_mmap2(unsigned long addr, unsigned long len,
 256         unsigned long prot, unsigned long flags, unsigned long fd,
 257         unsigned long pgoff)
 258 {
 259         /* Make sure the shift for mmap2 is constant (12), no matter what PAGE_SIZE
 260            we have. */
 261         return ksys_mmap_pgoff(addr, len, prot, flags, fd,
 262                                pgoff >> (PAGE_SHIFT - 12));
 263 }
 264 
 265 asmlinkage unsigned long sys_mmap(unsigned long addr, unsigned long len,
 266                 unsigned long prot, unsigned long flags, unsigned long fd,
 267                 unsigned long offset)
 268 {
 269         if (!(offset & ~PAGE_MASK)) {
 270                 return ksys_mmap_pgoff(addr, len, prot, flags, fd,
 271                                         offset >> PAGE_SHIFT);
 272         } else {
 273                 return -EINVAL;
 274         }
 275 }
 276 
 277 /* Fucking broken ABI */
 278 
 279 #ifdef CONFIG_64BIT
 280 asmlinkage long parisc_truncate64(const char __user * path,
 281                                         unsigned int high, unsigned int low)
 282 {
 283         return ksys_truncate(path, (long)high << 32 | low);
 284 }
 285 
 286 asmlinkage long parisc_ftruncate64(unsigned int fd,
 287                                         unsigned int high, unsigned int low)
 288 {
 289         return ksys_ftruncate(fd, (long)high << 32 | low);
 290 }
 291 
 292 /* stubs for the benefit of the syscall_table since truncate64 and truncate 
 293  * are identical on LP64 */
 294 asmlinkage long sys_truncate64(const char __user * path, unsigned long length)
 295 {
 296         return ksys_truncate(path, length);
 297 }
 298 asmlinkage long sys_ftruncate64(unsigned int fd, unsigned long length)
 299 {
 300         return ksys_ftruncate(fd, length);
 301 }
 302 asmlinkage long sys_fcntl64(unsigned int fd, unsigned int cmd, unsigned long arg)
 303 {
 304         return sys_fcntl(fd, cmd, arg);
 305 }
 306 #else
 307 
 308 asmlinkage long parisc_truncate64(const char __user * path,
 309                                         unsigned int high, unsigned int low)
 310 {
 311         return ksys_truncate(path, (loff_t)high << 32 | low);
 312 }
 313 
 314 asmlinkage long parisc_ftruncate64(unsigned int fd,
 315                                         unsigned int high, unsigned int low)
 316 {
 317         return sys_ftruncate64(fd, (loff_t)high << 32 | low);
 318 }
 319 #endif
 320 
 321 asmlinkage ssize_t parisc_pread64(unsigned int fd, char __user *buf, size_t count,
 322                                         unsigned int high, unsigned int low)
 323 {
 324         return ksys_pread64(fd, buf, count, (loff_t)high << 32 | low);
 325 }
 326 
 327 asmlinkage ssize_t parisc_pwrite64(unsigned int fd, const char __user *buf,
 328                         size_t count, unsigned int high, unsigned int low)
 329 {
 330         return ksys_pwrite64(fd, buf, count, (loff_t)high << 32 | low);
 331 }
 332 
 333 asmlinkage ssize_t parisc_readahead(int fd, unsigned int high, unsigned int low,
 334                                     size_t count)
 335 {
 336         return ksys_readahead(fd, (loff_t)high << 32 | low, count);
 337 }
 338 
 339 asmlinkage long parisc_fadvise64_64(int fd,
 340                         unsigned int high_off, unsigned int low_off,
 341                         unsigned int high_len, unsigned int low_len, int advice)
 342 {
 343         return ksys_fadvise64_64(fd, (loff_t)high_off << 32 | low_off,
 344                         (loff_t)high_len << 32 | low_len, advice);
 345 }
 346 
 347 asmlinkage long parisc_sync_file_range(int fd,
 348                         u32 hi_off, u32 lo_off, u32 hi_nbytes, u32 lo_nbytes,
 349                         unsigned int flags)
 350 {
 351         return ksys_sync_file_range(fd, (loff_t)hi_off << 32 | lo_off,
 352                         (loff_t)hi_nbytes << 32 | lo_nbytes, flags);
 353 }
 354 
 355 asmlinkage long parisc_fallocate(int fd, int mode, u32 offhi, u32 offlo,
 356                                 u32 lenhi, u32 lenlo)
 357 {
 358         return ksys_fallocate(fd, mode, ((u64)offhi << 32) | offlo,
 359                               ((u64)lenhi << 32) | lenlo);
 360 }
 361 
 362 long parisc_personality(unsigned long personality)
 363 {
 364         long err;
 365 
 366         if (personality(current->personality) == PER_LINUX32
 367             && personality(personality) == PER_LINUX)
 368                 personality = (personality & ~PER_MASK) | PER_LINUX32;
 369 
 370         err = sys_personality(personality);
 371         if (personality(err) == PER_LINUX32)
 372                 err = (err & ~PER_MASK) | PER_LINUX;
 373 
 374         return err;
 375 }