254 lines
6.1 KiB
C
254 lines
6.1 KiB
C
#include <linux/errno.h>
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#include <linux/sched.h>
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#include <linux/syscalls.h>
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#include <linux/mm.h>
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#include <linux/fs.h>
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#include <linux/smp.h>
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#include <linux/sem.h>
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#include <linux/msg.h>
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#include <linux/shm.h>
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#include <linux/stat.h>
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#include <linux/mman.h>
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#include <linux/file.h>
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#include <linux/utsname.h>
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#include <linux/personality.h>
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#include <linux/random.h>
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#include <asm/uaccess.h>
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#include <asm/ia32.h>
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/*
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* sys_pipe() is the normal C calling standard for creating
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* a pipe. It's not the way Unix traditionally does this, though.
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*/
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asmlinkage long sys_pipe(int __user *fildes)
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{
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int fd[2];
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int error;
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error = do_pipe(fd);
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if (!error) {
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if (copy_to_user(fildes, fd, 2*sizeof(int)))
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error = -EFAULT;
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}
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return error;
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}
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asmlinkage long sys_mmap(unsigned long addr, unsigned long len, unsigned long prot, unsigned long flags,
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unsigned long fd, unsigned long off)
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{
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long error;
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struct file * file;
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error = -EINVAL;
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if (off & ~PAGE_MASK)
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goto out;
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error = -EBADF;
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file = NULL;
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flags &= ~(MAP_EXECUTABLE | MAP_DENYWRITE);
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if (!(flags & MAP_ANONYMOUS)) {
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file = fget(fd);
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if (!file)
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goto out;
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}
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down_write(¤t->mm->mmap_sem);
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error = do_mmap_pgoff(file, addr, len, prot, flags, off >> PAGE_SHIFT);
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up_write(¤t->mm->mmap_sem);
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if (file)
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fput(file);
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out:
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return error;
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}
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static void find_start_end(unsigned long flags, unsigned long *begin,
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unsigned long *end)
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{
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if (!test_thread_flag(TIF_IA32) && (flags & MAP_32BIT)) {
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unsigned long new_begin;
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/* This is usually used needed to map code in small
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model, so it needs to be in the first 31bit. Limit
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it to that. This means we need to move the
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unmapped base down for this case. This can give
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conflicts with the heap, but we assume that glibc
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malloc knows how to fall back to mmap. Give it 1GB
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of playground for now. -AK */
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*begin = 0x40000000;
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*end = 0x80000000;
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if (current->flags & PF_RANDOMIZE) {
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new_begin = randomize_range(*begin, *begin + 0x02000000, 0);
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if (new_begin)
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*begin = new_begin;
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}
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} else {
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*begin = TASK_UNMAPPED_BASE;
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*end = TASK_SIZE;
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}
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}
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unsigned long
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arch_get_unmapped_area(struct file *filp, unsigned long addr,
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unsigned long len, unsigned long pgoff, unsigned long flags)
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{
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struct mm_struct *mm = current->mm;
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struct vm_area_struct *vma;
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unsigned long start_addr;
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unsigned long begin, end;
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if (flags & MAP_FIXED)
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return addr;
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find_start_end(flags, &begin, &end);
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if (len > end)
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return -ENOMEM;
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if (addr) {
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addr = PAGE_ALIGN(addr);
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vma = find_vma(mm, addr);
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if (end - len >= addr &&
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(!vma || addr + len <= vma->vm_start))
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return addr;
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}
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if (((flags & MAP_32BIT) || test_thread_flag(TIF_IA32))
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&& len <= mm->cached_hole_size) {
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mm->cached_hole_size = 0;
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mm->free_area_cache = begin;
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}
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addr = mm->free_area_cache;
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if (addr < begin)
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addr = begin;
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start_addr = addr;
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full_search:
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for (vma = find_vma(mm, addr); ; vma = vma->vm_next) {
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/* At this point: (!vma || addr < vma->vm_end). */
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if (end - len < addr) {
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/*
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* Start a new search - just in case we missed
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* some holes.
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*/
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if (start_addr != begin) {
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start_addr = addr = begin;
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mm->cached_hole_size = 0;
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goto full_search;
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}
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return -ENOMEM;
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}
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if (!vma || addr + len <= vma->vm_start) {
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/*
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* Remember the place where we stopped the search:
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*/
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mm->free_area_cache = addr + len;
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return addr;
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}
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if (addr + mm->cached_hole_size < vma->vm_start)
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mm->cached_hole_size = vma->vm_start - addr;
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addr = vma->vm_end;
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}
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}
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unsigned long
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arch_get_unmapped_area_topdown(struct file *filp, const unsigned long addr0,
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const unsigned long len, const unsigned long pgoff,
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const unsigned long flags)
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{
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struct vm_area_struct *vma;
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struct mm_struct *mm = current->mm;
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unsigned long addr = addr0;
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/* requested length too big for entire address space */
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if (len > TASK_SIZE)
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return -ENOMEM;
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if (flags & MAP_FIXED)
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return addr;
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/* for MAP_32BIT mappings we force the legact mmap base */
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if (!test_thread_flag(TIF_IA32) && (flags & MAP_32BIT))
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goto bottomup;
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/* requesting a specific address */
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if (addr) {
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addr = PAGE_ALIGN(addr);
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vma = find_vma(mm, addr);
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if (TASK_SIZE - len >= addr &&
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(!vma || addr + len <= vma->vm_start))
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return addr;
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}
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/* check if free_area_cache is useful for us */
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if (len <= mm->cached_hole_size) {
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mm->cached_hole_size = 0;
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mm->free_area_cache = mm->mmap_base;
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}
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/* either no address requested or can't fit in requested address hole */
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addr = mm->free_area_cache;
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/* make sure it can fit in the remaining address space */
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if (addr > len) {
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vma = find_vma(mm, addr-len);
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if (!vma || addr <= vma->vm_start)
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/* remember the address as a hint for next time */
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return (mm->free_area_cache = addr-len);
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}
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if (mm->mmap_base < len)
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goto bottomup;
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addr = mm->mmap_base-len;
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do {
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/*
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* Lookup failure means no vma is above this address,
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* else if new region fits below vma->vm_start,
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* return with success:
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*/
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vma = find_vma(mm, addr);
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if (!vma || addr+len <= vma->vm_start)
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/* remember the address as a hint for next time */
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return (mm->free_area_cache = addr);
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/* remember the largest hole we saw so far */
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if (addr + mm->cached_hole_size < vma->vm_start)
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mm->cached_hole_size = vma->vm_start - addr;
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/* try just below the current vma->vm_start */
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addr = vma->vm_start-len;
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} while (len < vma->vm_start);
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bottomup:
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/*
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* A failed mmap() very likely causes application failure,
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* so fall back to the bottom-up function here. This scenario
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* can happen with large stack limits and large mmap()
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* allocations.
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*/
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mm->cached_hole_size = ~0UL;
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mm->free_area_cache = TASK_UNMAPPED_BASE;
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addr = arch_get_unmapped_area(filp, addr0, len, pgoff, flags);
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/*
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* Restore the topdown base:
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*/
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mm->free_area_cache = mm->mmap_base;
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mm->cached_hole_size = ~0UL;
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return addr;
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}
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asmlinkage long sys_uname(struct new_utsname __user * name)
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{
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int err;
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down_read(&uts_sem);
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err = copy_to_user(name, utsname(), sizeof (*name));
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up_read(&uts_sem);
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if (personality(current->personality) == PER_LINUX32)
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err |= copy_to_user(&name->machine, "i686", 5);
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return err ? -EFAULT : 0;
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}
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