1 #include <linux/errno.h> 2 #include <linux/sched.h> 3 #include <linux/syscalls.h> 4 #include <linux/mm.h> 5 #include <linux/fs.h> 6 #include <linux/smp.h> 7 #include <linux/sem.h> 8 #include <linux/msg.h> 9 #include <linux/shm.h> 10 #include <linux/stat.h> 11 #include <linux/mman.h> 12 #include <linux/file.h> 13 #include <linux/utsname.h> 14 #include <linux/personality.h> 15 #include <linux/random.h> 16 17 #include <asm/uaccess.h> 18 #include <asm/ia32.h> 19 20 /* 21 * sys_pipe() is the normal C calling standard for creating 22 * a pipe. It's not the way Unix traditionally does this, though. 23 */ 24 asmlinkage long sys_pipe(int __user *fildes) 25 { 26 int fd[2]; 27 int error; 28 29 error = do_pipe(fd); 30 if (!error) { 31 if (copy_to_user(fildes, fd, 2*sizeof(int))) 32 error = -EFAULT; 33 } 34 return error; 35 } 36 37 asmlinkage long sys_mmap(unsigned long addr, unsigned long len, unsigned long prot, unsigned long flags, 38 unsigned long fd, unsigned long off) 39 { 40 long error; 41 struct file * file; 42 43 error = -EINVAL; 44 if (off & ~PAGE_MASK) 45 goto out; 46 47 error = -EBADF; 48 file = NULL; 49 flags &= ~(MAP_EXECUTABLE | MAP_DENYWRITE); 50 if (!(flags & MAP_ANONYMOUS)) { 51 file = fget(fd); 52 if (!file) 53 goto out; 54 } 55 down_write(¤t->mm->mmap_sem); 56 error = do_mmap_pgoff(file, addr, len, prot, flags, off >> PAGE_SHIFT); 57 up_write(¤t->mm->mmap_sem); 58 59 if (file) 60 fput(file); 61 out: 62 return error; 63 } 64 65 static void find_start_end(unsigned long flags, unsigned long *begin, 66 unsigned long *end) 67 { 68 if (!test_thread_flag(TIF_IA32) && (flags & MAP_32BIT)) { 69 unsigned long new_begin; 70 /* This is usually used needed to map code in small 71 model, so it needs to be in the first 31bit. Limit 72 it to that. This means we need to move the 73 unmapped base down for this case. This can give 74 conflicts with the heap, but we assume that glibc 75 malloc knows how to fall back to mmap. Give it 1GB 76 of playground for now. -AK */ 77 *begin = 0x40000000; 78 *end = 0x80000000; 79 if (current->flags & PF_RANDOMIZE) { 80 new_begin = randomize_range(*begin, *begin + 0x02000000, 0); 81 if (new_begin) 82 *begin = new_begin; 83 } 84 } else { 85 *begin = TASK_UNMAPPED_BASE; 86 *end = TASK_SIZE; 87 } 88 } 89 90 unsigned long 91 arch_get_unmapped_area(struct file *filp, unsigned long addr, 92 unsigned long len, unsigned long pgoff, unsigned long flags) 93 { 94 struct mm_struct *mm = current->mm; 95 struct vm_area_struct *vma; 96 unsigned long start_addr; 97 unsigned long begin, end; 98 99 if (flags & MAP_FIXED) 100 return addr; 101 102 find_start_end(flags, &begin, &end); 103 104 if (len > end) 105 return -ENOMEM; 106 107 if (addr) { 108 addr = PAGE_ALIGN(addr); 109 vma = find_vma(mm, addr); 110 if (end - len >= addr && 111 (!vma || addr + len <= vma->vm_start)) 112 return addr; 113 } 114 if (((flags & MAP_32BIT) || test_thread_flag(TIF_IA32)) 115 && len <= mm->cached_hole_size) { 116 mm->cached_hole_size = 0; 117 mm->free_area_cache = begin; 118 } 119 addr = mm->free_area_cache; 120 if (addr < begin) 121 addr = begin; 122 start_addr = addr; 123 124 full_search: 125 for (vma = find_vma(mm, addr); ; vma = vma->vm_next) { 126 /* At this point: (!vma || addr < vma->vm_end). */ 127 if (end - len < addr) { 128 /* 129 * Start a new search - just in case we missed 130 * some holes. 131 */ 132 if (start_addr != begin) { 133 start_addr = addr = begin; 134 mm->cached_hole_size = 0; 135 goto full_search; 136 } 137 return -ENOMEM; 138 } 139 if (!vma || addr + len <= vma->vm_start) { 140 /* 141 * Remember the place where we stopped the search: 142 */ 143 mm->free_area_cache = addr + len; 144 return addr; 145 } 146 if (addr + mm->cached_hole_size < vma->vm_start) 147 mm->cached_hole_size = vma->vm_start - addr; 148 149 addr = vma->vm_end; 150 } 151 } 152 153 154 unsigned long 155 arch_get_unmapped_area_topdown(struct file *filp, const unsigned long addr0, 156 const unsigned long len, const unsigned long pgoff, 157 const unsigned long flags) 158 { 159 struct vm_area_struct *vma; 160 struct mm_struct *mm = current->mm; 161 unsigned long addr = addr0; 162 163 /* requested length too big for entire address space */ 164 if (len > TASK_SIZE) 165 return -ENOMEM; 166 167 if (flags & MAP_FIXED) 168 return addr; 169 170 /* for MAP_32BIT mappings we force the legact mmap base */ 171 if (!test_thread_flag(TIF_IA32) && (flags & MAP_32BIT)) 172 goto bottomup; 173 174 /* requesting a specific address */ 175 if (addr) { 176 addr = PAGE_ALIGN(addr); 177 vma = find_vma(mm, addr); 178 if (TASK_SIZE - len >= addr && 179 (!vma || addr + len <= vma->vm_start)) 180 return addr; 181 } 182 183 /* check if free_area_cache is useful for us */ 184 if (len <= mm->cached_hole_size) { 185 mm->cached_hole_size = 0; 186 mm->free_area_cache = mm->mmap_base; 187 } 188 189 /* either no address requested or can't fit in requested address hole */ 190 addr = mm->free_area_cache; 191 192 /* make sure it can fit in the remaining address space */ 193 if (addr > len) { 194 vma = find_vma(mm, addr-len); 195 if (!vma || addr <= vma->vm_start) 196 /* remember the address as a hint for next time */ 197 return (mm->free_area_cache = addr-len); 198 } 199 200 if (mm->mmap_base < len) 201 goto bottomup; 202 203 addr = mm->mmap_base-len; 204 205 do { 206 /* 207 * Lookup failure means no vma is above this address, 208 * else if new region fits below vma->vm_start, 209 * return with success: 210 */ 211 vma = find_vma(mm, addr); 212 if (!vma || addr+len <= vma->vm_start) 213 /* remember the address as a hint for next time */ 214 return (mm->free_area_cache = addr); 215 216 /* remember the largest hole we saw so far */ 217 if (addr + mm->cached_hole_size < vma->vm_start) 218 mm->cached_hole_size = vma->vm_start - addr; 219 220 /* try just below the current vma->vm_start */ 221 addr = vma->vm_start-len; 222 } while (len < vma->vm_start); 223 224 bottomup: 225 /* 226 * A failed mmap() very likely causes application failure, 227 * so fall back to the bottom-up function here. This scenario 228 * can happen with large stack limits and large mmap() 229 * allocations. 230 */ 231 mm->cached_hole_size = ~0UL; 232 mm->free_area_cache = TASK_UNMAPPED_BASE; 233 addr = arch_get_unmapped_area(filp, addr0, len, pgoff, flags); 234 /* 235 * Restore the topdown base: 236 */ 237 mm->free_area_cache = mm->mmap_base; 238 mm->cached_hole_size = ~0UL; 239 240 return addr; 241 } 242 243 244 asmlinkage long sys_uname(struct new_utsname __user * name) 245 { 246 int err; 247 down_read(&uts_sem); 248 err = copy_to_user(name, utsname(), sizeof (*name)); 249 up_read(&uts_sem); 250 if (personality(current->personality) == PER_LINUX32) 251 err |= copy_to_user(&name->machine, "i686", 5); 252 return err ? -EFAULT : 0; 253 } 254