linux-2.6.33/get_unmapped_area()
をテンプレートにして作成
[
トップ
] [
新規
|
一覧
|
検索
|
最終更新
|
ヘルプ
|
ログイン
]
開始行:
*参照元 [#ab446093]
#backlinks
*説明 [#t1e69ecd]
-パス: [[linux-2.6.33/mm/mmap.c]]
-FIXME: これは何？
--説明
**引数 [#u611384f]
-struct file *filp
--
--[[linux-2.6.33/file]]
-unsigned long addr
--
-unsigned long len
--
-unsigned long pgoff
--
-unsigned long flags
--
**返り値 [#tece2720]
-unsigned long
--
**参考 [#zda2b135]
*実装 [#sa376f5a]
/* Get an address range which is currently unmapped.
* For shmat() with addr=0.
*
* Ugly calling convention alert:
* Return value with the low bits set means error value,
* ie
* if (ret & ~PAGE_MASK)
* error = ret;
*
* This function "knows" that -ENOMEM has the bits set.
*/
#ifndef HAVE_ARCH_UNMAPPED_AREA
-アーキテクチャ独自の get_unmapped_area() を定義していな...
下記の標準関数を使用する。
--[[linux-2.6.33/HAVE_ARCH_UNMAPPED_AREA]]
unsigned long
arch_get_unmapped_area(struct file *filp, unsigned long ...
unsigned long len, unsigned long pgoff, unsigned long ...
{
struct mm_struct *mm = current->mm;
struct vm_area_struct *vma;
unsigned long start_addr;
-
--[[linux-2.6.33/mm_struct]]
--[[linux-2.6.33/vm_area_struct]]
if (len > TASK_SIZE)
return -ENOMEM;
-
--[[linux-2.6.33/TASK_SIZE]]
if (flags & MAP_FIXED)
return addr;
-
--[[linux-2.6.33/MAP_FIXED]]
if (addr) {
addr = PAGE_ALIGN(addr);
-
--[[linux-2.6.33/PAGE_ALIGN()]]
vma = find_vma(mm, addr);
-
--[[linux-2.6.33/find_vma()]]
if (TASK_SIZE - len >= addr &&
(!vma || addr + len <= vma->vm_start))
return addr;
}
if (len > mm->cached_hole_size) {
start_addr = addr = mm->free_area_cache;
} else {
start_addr = addr = TASK_UNMAPPED_BASE;
mm->cached_hole_size = 0;
-
--[[linux-2.6.33/TASK_UNMAPPED_BASE]]
}
full_search:
for (vma = find_vma(mm, addr); ; vma = vma->vm_next) {
-
--[[linux-2.6.33/find_vma()]]
/* At this point: (!vma || addr < vma->vm_end). */
if (TASK_SIZE - len < addr) {
/*
* Start a new search - just in case we missed
* some holes.
*/
if (start_addr != TASK_UNMAPPED_BASE) {
addr = TASK_UNMAPPED_BASE;
start_addr = addr;
mm->cached_hole_size = 0;
goto full_search;
}
return -ENOMEM;
}
if (!vma || addr + len <= vma->vm_start) {
/*
* Remember the place where we stopped the search:
*/
mm->free_area_cache = addr + len;
return addr;
}
if (addr + mm->cached_hole_size < vma->vm_start)
mm->cached_hole_size = vma->vm_start - addr;
addr = vma->vm_end;
}
}
#endif
*コメント [#n7581223]
終了行:
*参照元 [#ab446093]
#backlinks
*説明 [#t1e69ecd]
-パス: [[linux-2.6.33/mm/mmap.c]]
-FIXME: これは何？
--説明
**引数 [#u611384f]
-struct file *filp
--
--[[linux-2.6.33/file]]
-unsigned long addr
--
-unsigned long len
--
-unsigned long pgoff
--
-unsigned long flags
--
**返り値 [#tece2720]
-unsigned long
--
**参考 [#zda2b135]
*実装 [#sa376f5a]
/* Get an address range which is currently unmapped.
* For shmat() with addr=0.
*
* Ugly calling convention alert:
* Return value with the low bits set means error value,
* ie
* if (ret & ~PAGE_MASK)
* error = ret;
*
* This function "knows" that -ENOMEM has the bits set.
*/
#ifndef HAVE_ARCH_UNMAPPED_AREA
-アーキテクチャ独自の get_unmapped_area() を定義していな...
下記の標準関数を使用する。
--[[linux-2.6.33/HAVE_ARCH_UNMAPPED_AREA]]
unsigned long
arch_get_unmapped_area(struct file *filp, unsigned long ...
unsigned long len, unsigned long pgoff, unsigned long ...
{
struct mm_struct *mm = current->mm;
struct vm_area_struct *vma;
unsigned long start_addr;
-
--[[linux-2.6.33/mm_struct]]
--[[linux-2.6.33/vm_area_struct]]
if (len > TASK_SIZE)
return -ENOMEM;
-
--[[linux-2.6.33/TASK_SIZE]]
if (flags & MAP_FIXED)
return addr;
-
--[[linux-2.6.33/MAP_FIXED]]
if (addr) {
addr = PAGE_ALIGN(addr);
-
--[[linux-2.6.33/PAGE_ALIGN()]]
vma = find_vma(mm, addr);
-
--[[linux-2.6.33/find_vma()]]
if (TASK_SIZE - len >= addr &&
(!vma || addr + len <= vma->vm_start))
return addr;
}
if (len > mm->cached_hole_size) {
start_addr = addr = mm->free_area_cache;
} else {
start_addr = addr = TASK_UNMAPPED_BASE;
mm->cached_hole_size = 0;
-
--[[linux-2.6.33/TASK_UNMAPPED_BASE]]
}
full_search:
for (vma = find_vma(mm, addr); ; vma = vma->vm_next) {
-
--[[linux-2.6.33/find_vma()]]
/* At this point: (!vma || addr < vma->vm_end). */
if (TASK_SIZE - len < addr) {
/*
* Start a new search - just in case we missed
* some holes.
*/
if (start_addr != TASK_UNMAPPED_BASE) {
addr = TASK_UNMAPPED_BASE;
start_addr = addr;
mm->cached_hole_size = 0;
goto full_search;
}
return -ENOMEM;
}
if (!vma || addr + len <= vma->vm_start) {
/*
* Remember the place where we stopped the search:
*/
mm->free_area_cache = addr + len;
return addr;
}
if (addr + mm->cached_hole_size < vma->vm_start)
mm->cached_hole_size = vma->vm_start - addr;
addr = vma->vm_end;
}
}
#endif
*コメント [#n7581223]
ページ名:
![[PukiWiki]](image/pukiwiki.png "[PukiWiki]")
