- 追加された行はこの色です。
- 削除された行はこの色です。
*参照元 [#cc520445]
#backlinks
*説明 [#b741f145]
-パス: [[linux-2.6.33/mm/mmap.c]]
-FIXME: これは何？
--説明
**引数 [#ue41253b]
-struct file *file
--
--[[linux-2.6.33/file]]
unsigned long addr
-unsigned long addr
--
unsigned long len
-unsigned long len
--
unsigned long flags
-unsigned long flags
--
unsigned int vm_flags
-unsigned int vm_flags
--
unsigned long pgoff
-unsigned long pgoff
--
**返り値 [#w4132174]
-long
-unsigned long
--
**参考 [#a1dae6d1]
*実装 [#t5cc2978]
unsigned long mmap_region(struct file *file, unsigned long addr,
unsigned long len, unsigned long flags,
unsigned int vm_flags, unsigned long pgoff)
{
struct mm_struct *mm = current->mm;
struct vm_area_struct *vma, *prev;
int correct_wcount = 0;
int error;
struct rb_node **rb_link, *rb_parent;
unsigned long charged = 0;
struct inode *inode = file ? file->f_path.dentry->d_inode : NULL;
-
--[[linux-2.6.33/current(global)]]
--[[linux-2.6.33/mm_struct]]
--[[linux-2.6.33/vm_area_struct]]
--[[linux-2.6.33/rb_node]]
--[[linux-2.6.33/inode]]
/* Clear old maps */
error = -ENOMEM;
-
--[[linux-2.6.33/ENOMEM]]
munmap_back:
vma = find_vma_prepare(mm, addr, &prev, &rb_link, &rb_parent);
if (vma && vma->vm_start < addr + len) {
if (do_munmap(mm, addr, len))
return -ENOMEM;
goto munmap_back;
}
-
--[[linux-2.6.33/find_vma_prepare()]]
--[[linux-2.6.33/do_munmap()]]
/* Check against address space limit. */
if (!may_expand_vm(mm, len >> PAGE_SHIFT))
return -ENOMEM;
-
--[[linux-2.6.33/may_expand_vm()]]
--[[linux-2.6.33/PAGE_SHIFT]]
/*
* Set 'VM_NORESERVE' if we should not account for the
* memory use of this mapping.
*/
if ((flags & MAP_NORESERVE)) {
/* We honor MAP_NORESERVE if allowed to overcommit */
if (sysctl_overcommit_memory != OVERCOMMIT_NEVER)
vm_flags |= VM_NORESERVE;
/* hugetlb applies strict overcommit unless MAP_NORESERVE */
if (file && is_file_hugepages(file))
vm_flags |= VM_NORESERVE;
}
-
--[[linux-2.6.33/MAP_NORESERVE]]
--[[linux-2.6.33/sysctl_overcommit_memory(global)]]
--[[linux-2.6.33/OVERCOMMIT_NEVER]]
--[[linux-2.6.33/VM_NORESERVE]]
--[[linux-2.6.33/is_file_hugepages()]]
/*
* Private writable mapping: check memory availability
*/
if (accountable_mapping(file, vm_flags)) {
charged = len >> PAGE_SHIFT;
if (security_vm_enough_memory(charged))
return -ENOMEM;
vm_flags |= VM_ACCOUNT;
}
-
--[[linux-2.6.33/accountable_mapping()]]
--[[linux-2.6.33/security_vm_enough_memory()]]
--[[linux-2.6.33/VM_ACCOUNT]]
/*
* Can we just expand an old mapping?
*/
vma = vma_merge(mm, prev, addr, addr + len, vm_flags, NULL, file, pgoff, NULL);
if (vma)
goto out;
-
--[[linux-2.6.33/vma_merge()]]
/*
* Determine the object being mapped and call the appropriate
* specific mapper. the address has already been validated, but
* not unmapped, but the maps are removed from the list.
*/
vma = kmem_cache_zalloc(vm_area_cachep, GFP_KERNEL);
if (!vma) {
error = -ENOMEM;
goto unacct_error;
}
-
--[[linux-2.6.33/kmem_cache_zalloc()]]
--[[linux-2.6.33/vm_area_cachep(global)]]
--[[linux-2.6.33/GFP_KERNEL]]
vma->vm_mm = mm;
vma->vm_start = addr;
vma->vm_end = addr + len;
vma->vm_flags = vm_flags;
vma->vm_page_prot = vm_get_page_prot(vm_flags);
vma->vm_pgoff = pgoff;
-
--[[linux-2.6.33/vm_get_page_prot()]]
if (file) {
error = -EINVAL;
if (vm_flags & (VM_GROWSDOWN|VM_GROWSUP))
goto free_vma;
if (vm_flags & VM_DENYWRITE) {
error = deny_write_access(file);
if (error)
goto free_vma;
correct_wcount = 1;
}
-
--[[linux-2.6.33/VM_GROWSDOWN]]
--[[linux-2.6.33/VM_GROWSUP]]
--[[linux-2.6.33/VM_DENYWRITE]]
--[[linux-2.6.33/deny_write_access()]]
vma->vm_file = file;
get_file(file);
error = file->f_op->mmap(file, vma);
if (error)
goto unmap_and_free_vma;
if (vm_flags & VM_EXECUTABLE)
added_exe_file_vma(mm);
-
--[[linux-2.6.33/get_file()]]
--[[linux-2.6.33/VM_EXECUTABLE]]
--[[linux-2.6.33/added_exe_file_vma()]]
/* Can addr have changed??
*
* Answer: Yes, several device drivers can do it in their
* f_op->mmap method. -DaveM
*/
addr = vma->vm_start;
pgoff = vma->vm_pgoff;
vm_flags = vma->vm_flags;
} else if (vm_flags & VM_SHARED) {
error = shmem_zero_setup(vma);
if (error)
goto free_vma;
-
--[[linux-2.6.33/VM_SHARED]]
--[[linux-2.6.33/shmem_zero_setup()]]
}
if (vma_wants_writenotify(vma)) {
pgprot_t pprot = vma->vm_page_prot;
/* Can vma->vm_page_prot have changed??
*
* Answer: Yes, drivers may have changed it in their
* f_op->mmap method.
*
* Ensures that vmas marked as uncached stay that way.
*/
vma->vm_page_prot = vm_get_page_prot(vm_flags & ~VM_SHARED);
if (pgprot_val(pprot) == pgprot_val(pgprot_noncached(pprot)))
vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
-
--[[linux-2.6.33/pgprot_t]]
--[[linux-2.6.33/vm_get_page_prot()]]
--[[linux-2.6.33/pgprot_val()]]
--[[linux-2.6.33/pgprot_noncached()]]
}
vma_link(mm, vma, prev, rb_link, rb_parent);
file = vma->vm_file;
-
--[[linux-2.6.33/vma_link()]]
/* Once vma denies write, undo our temporary denial count */
if (correct_wcount)
atomic_inc(&inode->i_writecount);
-
--[[linux-2.6.33/atomic_inc()]]
out:
perf_event_mmap(vma);
-
--[[linux-2.6.33/perf_event_mmap()]]
mm->total_vm += len >> PAGE_SHIFT;
vm_stat_account(mm, vm_flags, file, len >> PAGE_SHIFT);
-
--[[linux-2.6.33/vm_stat_account()]]
if (vm_flags & VM_LOCKED) {
/*
* makes pages present; downgrades, drops, reacquires mmap_sem
*/
long nr_pages = mlock_vma_pages_range(vma, addr, addr + len);
if (nr_pages < 0)
return nr_pages; /* vma gone! */
mm->locked_vm += (len >> PAGE_SHIFT) - nr_pages;
} else if ((flags & MAP_POPULATE) && !(flags & MAP_NONBLOCK))
make_pages_present(addr, addr + len);
return addr;
-
--[[linux-2.6.33/VM_LOCKED]]
--[[linux-2.6.33/mlock_vma_pages_range()]]
--[[linux-2.6.33/MAP_POPULATE]]
--[[linux-2.6.33/MAP_NONBLOCK]]
--[[linux-2.6.33/make_pages_present()]]
unmap_and_free_vma:
if (correct_wcount)
atomic_inc(&inode->i_writecount);
vma->vm_file = NULL;
fput(file);
-
--[[linux-2.6.33/fput()]]
/* Undo any partial mapping done by a device driver. */
unmap_region(mm, vma, prev, vma->vm_start, vma->vm_end);
charged = 0;
-
--[[linux-2.6.33/unmap_region()]]
free_vma:
kmem_cache_free(vm_area_cachep, vma);
-
--[[linux-2.6.33/kmem_cache_free()]]
unacct_error:
if (charged)
vm_unacct_memory(charged);
return error;
-
--[[linux-2.6.33/vm_unacct_memory()]]
}
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