ed8cae8ba0
This patch introduces the new syscall pipe2 which is like pipe but it also takes an additional parameter which takes a flag value. This patch implements the handling of O_CLOEXEC for the flag. I did not add support for the new syscall for the architectures which have a special sys_pipe implementation. I think the maintainers of those archs have the chance to go with the unified implementation but that's up to them. The implementation introduces do_pipe_flags. I did that instead of changing all callers of do_pipe because some of the callers are written in assembler. I would probably screw up changing the assembly code. To avoid breaking code do_pipe is now a small wrapper around do_pipe_flags. Once all callers are changed over to do_pipe_flags the old do_pipe function can be removed. The following test must be adjusted for architectures other than x86 and x86-64 and in case the syscall numbers changed. ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ #include <fcntl.h> #include <stdio.h> #include <unistd.h> #include <sys/syscall.h> #ifndef __NR_pipe2 # ifdef __x86_64__ # define __NR_pipe2 293 # elif defined __i386__ # define __NR_pipe2 331 # else # error "need __NR_pipe2" # endif #endif int main (void) { int fd[2]; if (syscall (__NR_pipe2, fd, 0) != 0) { puts ("pipe2(0) failed"); return 1; } for (int i = 0; i < 2; ++i) { int coe = fcntl (fd[i], F_GETFD); if (coe == -1) { puts ("fcntl failed"); return 1; } if (coe & FD_CLOEXEC) { printf ("pipe2(0) set close-on-exit for fd[%d]\n", i); return 1; } } close (fd[0]); close (fd[1]); if (syscall (__NR_pipe2, fd, O_CLOEXEC) != 0) { puts ("pipe2(O_CLOEXEC) failed"); return 1; } for (int i = 0; i < 2; ++i) { int coe = fcntl (fd[i], F_GETFD); if (coe == -1) { puts ("fcntl failed"); return 1; } if ((coe & FD_CLOEXEC) == 0) { printf ("pipe2(O_CLOEXEC) does not set close-on-exit for fd[%d]\n", i); return 1; } } close (fd[0]); close (fd[1]); puts ("OK"); return 0; } ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Signed-off-by: Ulrich Drepper <drepper@redhat.com> Acked-by: Davide Libenzi <davidel@xmailserver.org> Cc: Michael Kerrisk <mtk.manpages@googlemail.com> Cc: <linux-arch@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
286 lines
6.9 KiB
C
286 lines
6.9 KiB
C
/*
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* This file contains various system calls that have different calling
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* conventions on different platforms.
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*
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* Copyright (C) 1999-2000, 2002-2003, 2005 Hewlett-Packard Co
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* David Mosberger-Tang <davidm@hpl.hp.com>
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*/
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#include <linux/errno.h>
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#include <linux/fs.h>
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#include <linux/mm.h>
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#include <linux/mman.h>
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#include <linux/sched.h>
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#include <linux/shm.h>
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#include <linux/file.h> /* doh, must come after sched.h... */
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#include <linux/smp.h>
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#include <linux/syscalls.h>
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#include <linux/highuid.h>
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#include <linux/hugetlb.h>
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#include <asm/shmparam.h>
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#include <asm/uaccess.h>
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unsigned long
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arch_get_unmapped_area (struct file *filp, unsigned long addr, unsigned long len,
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unsigned long pgoff, unsigned long flags)
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{
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long map_shared = (flags & MAP_SHARED);
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unsigned long start_addr, align_mask = PAGE_SIZE - 1;
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struct mm_struct *mm = current->mm;
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struct vm_area_struct *vma;
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if (len > RGN_MAP_LIMIT)
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return -ENOMEM;
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/* handle fixed mapping: prevent overlap with huge pages */
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if (flags & MAP_FIXED) {
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if (is_hugepage_only_range(mm, addr, len))
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return -EINVAL;
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return addr;
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}
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#ifdef CONFIG_HUGETLB_PAGE
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if (REGION_NUMBER(addr) == RGN_HPAGE)
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addr = 0;
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#endif
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if (!addr)
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addr = mm->free_area_cache;
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if (map_shared && (TASK_SIZE > 0xfffffffful))
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/*
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* For 64-bit tasks, align shared segments to 1MB to avoid potential
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* performance penalty due to virtual aliasing (see ASDM). For 32-bit
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* tasks, we prefer to avoid exhausting the address space too quickly by
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* limiting alignment to a single page.
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*/
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align_mask = SHMLBA - 1;
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full_search:
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start_addr = addr = (addr + align_mask) & ~align_mask;
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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 (TASK_SIZE - len < addr || RGN_MAP_LIMIT - len < REGION_OFFSET(addr)) {
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if (start_addr != TASK_UNMAPPED_BASE) {
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/* Start a new search --- just in case we missed some holes. */
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addr = TASK_UNMAPPED_BASE;
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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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/* Remember the address where we stopped this search: */
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mm->free_area_cache = addr + len;
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return addr;
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}
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addr = (vma->vm_end + align_mask) & ~align_mask;
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}
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}
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asmlinkage long
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ia64_getpriority (int which, int who)
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{
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long prio;
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prio = sys_getpriority(which, who);
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if (prio >= 0) {
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force_successful_syscall_return();
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prio = 20 - prio;
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}
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return prio;
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}
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/* XXX obsolete, but leave it here until the old libc is gone... */
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asmlinkage unsigned long
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sys_getpagesize (void)
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{
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return PAGE_SIZE;
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}
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asmlinkage unsigned long
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ia64_brk (unsigned long brk)
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{
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unsigned long rlim, retval, newbrk, oldbrk;
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struct mm_struct *mm = current->mm;
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/*
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* Most of this replicates the code in sys_brk() except for an additional safety
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* check and the clearing of r8. However, we can't call sys_brk() because we need
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* to acquire the mmap_sem before we can do the test...
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*/
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down_write(&mm->mmap_sem);
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if (brk < mm->end_code)
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goto out;
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newbrk = PAGE_ALIGN(brk);
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oldbrk = PAGE_ALIGN(mm->brk);
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if (oldbrk == newbrk)
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goto set_brk;
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/* Always allow shrinking brk. */
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if (brk <= mm->brk) {
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if (!do_munmap(mm, newbrk, oldbrk-newbrk))
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goto set_brk;
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goto out;
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}
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/* Check against unimplemented/unmapped addresses: */
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if ((newbrk - oldbrk) > RGN_MAP_LIMIT || REGION_OFFSET(newbrk) > RGN_MAP_LIMIT)
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goto out;
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/* Check against rlimit.. */
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rlim = current->signal->rlim[RLIMIT_DATA].rlim_cur;
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if (rlim < RLIM_INFINITY && brk - mm->start_data > rlim)
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goto out;
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/* Check against existing mmap mappings. */
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if (find_vma_intersection(mm, oldbrk, newbrk+PAGE_SIZE))
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goto out;
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/* Ok, looks good - let it rip. */
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if (do_brk(oldbrk, newbrk-oldbrk) != oldbrk)
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goto out;
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set_brk:
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mm->brk = brk;
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out:
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retval = mm->brk;
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up_write(&mm->mmap_sem);
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force_successful_syscall_return();
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return retval;
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}
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/*
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* On IA-64, we return the two file descriptors in ret0 and ret1 (r8
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* and r9) as this is faster than doing a copy_to_user().
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*/
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asmlinkage long
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sys_pipe (void)
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{
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struct pt_regs *regs = task_pt_regs(current);
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int fd[2];
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int retval;
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retval = do_pipe_flags(fd, 0);
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if (retval)
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goto out;
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retval = fd[0];
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regs->r9 = fd[1];
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out:
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return retval;
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}
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int ia64_mmap_check(unsigned long addr, unsigned long len,
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unsigned long flags)
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{
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unsigned long roff;
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/*
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* Don't permit mappings into unmapped space, the virtual page table
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* of a region, or across a region boundary. Note: RGN_MAP_LIMIT is
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* equal to 2^n-PAGE_SIZE (for some integer n <= 61) and len > 0.
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*/
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roff = REGION_OFFSET(addr);
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if ((len > RGN_MAP_LIMIT) || (roff > (RGN_MAP_LIMIT - len)))
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return -EINVAL;
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return 0;
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}
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static inline unsigned long
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do_mmap2 (unsigned long addr, unsigned long len, int prot, int flags, int fd, unsigned long pgoff)
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{
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struct file *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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return -EBADF;
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if (!file->f_op || !file->f_op->mmap) {
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addr = -ENODEV;
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goto out;
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}
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}
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/* Careful about overflows.. */
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len = PAGE_ALIGN(len);
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if (!len || len > TASK_SIZE) {
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addr = -EINVAL;
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goto out;
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}
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down_write(¤t->mm->mmap_sem);
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addr = do_mmap_pgoff(file, addr, len, prot, flags, pgoff);
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up_write(¤t->mm->mmap_sem);
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out: if (file)
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fput(file);
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return addr;
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}
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/*
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* mmap2() is like mmap() except that the offset is expressed in units
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* of PAGE_SIZE (instead of bytes). This allows to mmap2() (pieces
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* of) files that are larger than the address space of the CPU.
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*/
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asmlinkage unsigned long
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sys_mmap2 (unsigned long addr, unsigned long len, int prot, int flags, int fd, long pgoff)
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{
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addr = do_mmap2(addr, len, prot, flags, fd, pgoff);
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if (!IS_ERR((void *) addr))
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force_successful_syscall_return();
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return addr;
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}
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asmlinkage unsigned long
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sys_mmap (unsigned long addr, unsigned long len, int prot, int flags, int fd, long off)
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{
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if (offset_in_page(off) != 0)
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return -EINVAL;
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addr = do_mmap2(addr, len, prot, flags, fd, off >> PAGE_SHIFT);
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if (!IS_ERR((void *) addr))
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force_successful_syscall_return();
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return addr;
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}
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asmlinkage unsigned long
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ia64_mremap (unsigned long addr, unsigned long old_len, unsigned long new_len, unsigned long flags,
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unsigned long new_addr)
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{
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extern unsigned long do_mremap (unsigned long addr,
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unsigned long old_len,
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unsigned long new_len,
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unsigned long flags,
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unsigned long new_addr);
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down_write(¤t->mm->mmap_sem);
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{
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addr = do_mremap(addr, old_len, new_len, flags, new_addr);
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}
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up_write(¤t->mm->mmap_sem);
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if (IS_ERR((void *) addr))
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return addr;
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force_successful_syscall_return();
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return addr;
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}
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#ifndef CONFIG_PCI
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asmlinkage long
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sys_pciconfig_read (unsigned long bus, unsigned long dfn, unsigned long off, unsigned long len,
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void *buf)
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{
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return -ENOSYS;
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}
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asmlinkage long
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sys_pciconfig_write (unsigned long bus, unsigned long dfn, unsigned long off, unsigned long len,
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void *buf)
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{
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return -ENOSYS;
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}
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#endif /* CONFIG_PCI */
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