mm: implement access_remote_vm

Provide an alternative to access_process_vm that allows the caller to obtain a
reference to the supplied mm_struct.

Signed-off-by: Stephen Wilson <wilsons@start.ca>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
This commit is contained in:
Stephen Wilson 2011-03-13 15:49:20 -04:00 committed by Al Viro
parent 206cb63657
commit 5ddd36b9c5
2 changed files with 18 additions and 0 deletions

View file

@ -971,6 +971,8 @@ static inline int handle_mm_fault(struct mm_struct *mm,
extern int make_pages_present(unsigned long addr, unsigned long end);
extern int access_process_vm(struct task_struct *tsk, unsigned long addr, void *buf, int len, int write);
extern int access_remote_vm(struct mm_struct *mm, unsigned long addr,
void *buf, int len, int write);
int __get_user_pages(struct task_struct *tsk, struct mm_struct *mm,
unsigned long start, int len, unsigned int foll_flags,

View file

@ -3711,6 +3711,22 @@ static int __access_remote_vm(struct task_struct *tsk, struct mm_struct *mm,
return buf - old_buf;
}
/**
* @access_remote_vm - access another process' address space
* @mm: the mm_struct of the target address space
* @addr: start address to access
* @buf: source or destination buffer
* @len: number of bytes to transfer
* @write: whether the access is a write
*
* The caller must hold a reference on @mm.
*/
int access_remote_vm(struct mm_struct *mm, unsigned long addr,
void *buf, int len, int write)
{
return __access_remote_vm(NULL, mm, addr, buf, len, write);
}
/*
* Access another process' address space.
* Source/target buffer must be kernel space,