*参照元 [#pc715bee]
#backlinks
*説明 [#j9cfcbb0]
-パス: [[linux-2.6.33/mm/mmap.c]]
-FIXME: これは何？
--説明
**引数 [#m7057ac7]
-struct file *file
--
--[[linux-2.6.33/file]]
-unsigned long addr
--
-unsigned long len
--
-unsigned long prot
--
-unsigned long flags
--
-unsigned long pgoff
--
**返り値 [#mb6e3e83]
-unsigned long
--
**参考 [#d593394c]
*実装 [#ye9c9916]
/*
* The caller must hold down_write(¤t->mm->mmap_sem).
*/
unsigned long do_mmap_pgoff(struct file *file, unsigned long addr,
unsigned long len, unsigned long prot,
unsigned long flags, unsigned long pgoff)
{
struct mm_struct * mm = current->mm;
struct inode *inode;
unsigned int vm_flags;
int error;
unsigned long reqprot = prot;
-
--[[linux-2.6.33/current(global)]]
--[[linux-2.6.33/mm_struct]]
--[[linux-2.6.33/inode]]
/*
* Does the application expect PROT_READ to imply PROT_EXEC?
*
* (the exception is when the underlying filesystem is noexec
* mounted, in which case we dont add PROT_EXEC.)
*/
if ((prot & PROT_READ) && (current->personality & READ_IMPLIES_EXEC))
if (!(file && (file->f_path.mnt->mnt_flags & MNT_NOEXEC)))
prot |= PROT_EXEC;
-
--[[linux-2.6.33/PROT_READ]]
--[[linux-2.6.33/READ_IMPLIES_EXEC]]
--[[linux-2.6.33/MNT_NOEXEC]]
--[[linux-2.6.33/PROT_EXEC]]
if (!len)
return -EINVAL;
-
--[[linux-2.6.33/EINVAL]]
if (!(flags & MAP_FIXED))
addr = round_hint_to_min(addr);
-
--[[linux-2.6.33/MAP_FIXED]]
--[[linux-2.6.33/round_hint_to_min()]]
/* Careful about overflows.. */
len = PAGE_ALIGN(len);
if (!len)
return -ENOMEM;
-
--[[linux-2.6.33/PAGE_ALIGN()]]
--[[linux-2.6.33/ENOMEM]]
/* offset overflow? */
if ((pgoff + (len >> PAGE_SHIFT)) < pgoff)
return -EOVERFLOW;
-
--[[linux-2.6.33/PAGE_SHIFT]]
--[[linux-2.6.33/EOVERFLOW]]
/* Too many mappings? */
if (mm->map_count > sysctl_max_map_count)
return -ENOMEM;
-
--[[linux-2.6.33/sysctl_max_map_count(global)]]
/* Obtain the address to map to. we verify (or select) it and ensure
* that it represents a valid section of the address space.
*/
addr = get_unmapped_area(file, addr, len, pgoff, flags);
if (addr & ~PAGE_MASK)
return addr;
-
--[[linux-2.6.33/get_unmapped_area()]]
--[[linux-2.6.33/PAGE_MASK]]
/* Do simple checking here so the lower-level routines won't have
* to. we assume access permissions have been handled by the open
* of the memory object, so we don't do any here.
*/
vm_flags = calc_vm_prot_bits(prot) | calc_vm_flag_bits(flags) |
mm->def_flags | VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC;
-
--[[linux-2.6.33/calc_vm_prot_bits()]]
--[[linux-2.6.33/calc_vm_flag_bits()]]
--[[linux-2.6.33/VM_MAYREAD]]
--[[linux-2.6.33/VM_MAYWRITE]]
--[[linux-2.6.33/VM_MAYEXEC]]
if (flags & MAP_LOCKED)
if (!can_do_mlock())
return -EPERM;
-
--[[linux-2.6.33/MAP_LOCKED]]
--[[linux-2.6.33/can_do_mlock()]]
--[[linux-2.6.33/EPERM]]
/* mlock MCL_FUTURE? */
if (vm_flags & VM_LOCKED) {
unsigned long locked, lock_limit;
locked = len >> PAGE_SHIFT;
locked += mm->locked_vm;
lock_limit = current->signal->rlim[RLIMIT_MEMLOCK].rlim_cur;
lock_limit >>= PAGE_SHIFT;
if (locked > lock_limit && !capable(CAP_IPC_LOCK))
return -EAGAIN;
}
-
--[[linux-2.6.33/VM_LOCKED]]
--[[linux-2.6.33/RLIMIT_MEMLOCK]]
--[[linux-2.6.33/capable()]]
--[[linux-2.6.33/CAP_IPC_LOCK]]
--[[linux-2.6.33/EAGAIN]]
inode = file ? file->f_path.dentry->d_inode : NULL;
if (file) {
switch (flags & MAP_TYPE) {
case MAP_SHARED:
if ((prot&PROT_WRITE) && !(file->f_mode&FMODE_WRITE))
return -EACCES;
-
--[[linux-2.6.33/MAP_TYPE]]
--[[linux-2.6.33/PROT_WRITE]]
--[[linux-2.6.33/FMODE_WRITE]]
--[[linux-2.6.33/EACCES]]
/*
* Make sure we don't allow writing to an append-only
* file..
*/
if (IS_APPEND(inode) && (file->f_mode & FMODE_WRITE))
return -EACCES;
-
--[[linux-2.6.33/IS_APPEND()]]
/*
* Make sure there are no mandatory locks on the file.
*/
if (locks_verify_locked(inode))
return -EAGAIN;
-
--[[linux-2.6.33/locks_verify_locked()]]
vm_flags |= VM_SHARED | VM_MAYSHARE;
if (!(file->f_mode & FMODE_WRITE))
vm_flags &= ~(VM_MAYWRITE | VM_SHARED);
/* fall through */
-
--[[linux-2.6.33/VM_MAYSHARE]]
case MAP_PRIVATE:
if (!(file->f_mode & FMODE_READ))
return -EACCES;
-
--[[linux-2.6.33/MAP_PRIVATE]]
--[[linux-2.6.33/FMODE_READ]]
if (file->f_path.mnt->mnt_flags & MNT_NOEXEC) {
if (vm_flags & VM_EXEC)
return -EPERM;
vm_flags &= ~VM_MAYEXEC;
}
-
--[[linux-2.6.33/MNT_NOEXEC]]
--[[linux-2.6.33/VM_EXEC]]
--[[linux-2.6.33/VM_MAYEXEC]]
if (!file->f_op || !file->f_op->mmap)
return -ENODEV;
break;
-
--[[linux-2.6.33/ENODEV]]
default:
return -EINVAL;
-
--[[linux-2.6.33/EINVAL]]
}
} else {
switch (flags & MAP_TYPE) {
case MAP_SHARED:
/*
* Ignore pgoff.
*/
pgoff = 0;
vm_flags |= VM_SHARED | VM_MAYSHARE;
break;
case MAP_PRIVATE:
/*
* Set pgoff according to addr for anon_vma.
*/
pgoff = addr >> PAGE_SHIFT;
break;
default:
return -EINVAL;
}
}
error = security_file_mmap(file, reqprot, prot, flags, addr, 0);
if (error)
return error;
-
--[[linux-2.6.33/security_file_mmap()]]
return mmap_region(file, addr, len, flags, vm_flags, pgoff);
-
--[[linux-2.6.33/mmap_region()]]
}
EXPORT_SYMBOL(do_mmap_pgoff);
-ライセンスに関係なくシンボルを公開する。
--[[linux-2.6.33/EXPORT_SYMBOL()]]
*コメント [#s12f1c2a]
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